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Khan S, Chand S, Sivasakthi P, Samanta PK, Chakraborty C. A Highly Robust and Conducting Ultramicroporous 3D Fe(II)-Based Metal-Organic Framework for Efficient Energy Storage. Small 2024:e2401102. [PMID: 38573909 DOI: 10.1002/smll.202401102] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/10/2024] [Revised: 03/21/2024] [Indexed: 04/06/2024]
Abstract
Exploitation of metal-organic framework (MOF) materials as active electrodes for energy storage or conversion is reasonably challenging owing to their poor robustness against various acidic/basic conditions and conventionally low electric conductivity. Keeping this in perspective, herein, a 3D ultramicroporous triazolate Fe-MOF (abbreviated as Fe-MET) is judiciously employed using cheap and commercially available starting materials. Fe-MET possesses ultra-stability against various chemical environments (pH-1 to pH-14 with varied organic solvents) and is highly electrically conductive (σ = 0.19 S m-1) in one fell swoop. By taking advantage of the properties mentioned above, Fe-MET electrodes give prominence to electrochemical capacitor (EC) performance by delivering an astounding gravimetric (304 F g-1) and areal (181 mF cm-2) capacitance at 0.5 A g-1 current density with exceptionally high cycling stability. Implementation of Fe-MET as an exclusive (by not using any conductive additives) EC electrode in solid-state energy storage devices outperforms most of the reported MOF-based EC materials and even surpasses certain porous carbon and graphene materials, showcasing superior capabilities and great promise compared to various other alternatives as energy storage materials.
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Affiliation(s)
- Soumen Khan
- Department of Chemistry, Birla Institute of Technology & Science (BITS) Pilani, Hyderabad Campus Jawaharnagar, Samirpet, Hyderabad, Telangana, 500078, India
- Materials Center for Sustainable Energy & Environment (McSEE), Birla Institute of Technology & Science (BITS) Pilani, Hyderabad Campus, Jawaharnagar, Samirpet, Hyderabad, Telangana, 500078, India
| | - Santanu Chand
- Department of Applied Chemistry, Graduate School of Engineering, The University of Tokyo, Bunkyo-ku, Tokyo, 113-8656, Japan
| | - Pandiyan Sivasakthi
- Department of Chemistry, Birla Institute of Technology & Science (BITS) Pilani, Hyderabad Campus Jawaharnagar, Samirpet, Hyderabad, Telangana, 500078, India
| | - Pralok K Samanta
- Department of Chemistry, Birla Institute of Technology & Science (BITS) Pilani, Hyderabad Campus Jawaharnagar, Samirpet, Hyderabad, Telangana, 500078, India
| | - Chanchal Chakraborty
- Department of Chemistry, Birla Institute of Technology & Science (BITS) Pilani, Hyderabad Campus Jawaharnagar, Samirpet, Hyderabad, Telangana, 500078, India
- Materials Center for Sustainable Energy & Environment (McSEE), Birla Institute of Technology & Science (BITS) Pilani, Hyderabad Campus, Jawaharnagar, Samirpet, Hyderabad, Telangana, 500078, India
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Groen JA, Crezee J, van Laarhoven HWM, Coolen BF, Strijkers GJ, Bijlsma MF, Kok HP. Robust, planning-based targeted locoregional tumour heating in small animals. Phys Med Biol 2024; 69:085017. [PMID: 38471172 DOI: 10.1088/1361-6560/ad3324] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2023] [Accepted: 03/12/2024] [Indexed: 03/14/2024]
Abstract
Objective.To improve hyperthermia in clinical practice, pre-clinical hyperthermia research is essential to investigate hyperthermia effects and assess novel treatment strategies. Translating pre-clinical hyperthermia findings into clinically viable protocols requires laboratory animal treatment techniques similar to clinical hyperthermia techniques. The ALBA micro8 electromagnetic heating system (Med-logix SRL, Rome, Italy) has recently been developed to provide the targeted locoregional tumour heating currently lacking for pre-clinical research. This study evaluates the heat focusing properties of this device and its ability to induce robust locoregional tumour heating under realistic physiological conditions using simulations.Approach.Simulations were performed using the Plan2Heat treatment planning package (Amsterdam UMC, the Netherlands). First, the specific absorption rate (SAR) focus was characterised using a homogeneous phantom. Hereafter, a digital mouse model was used for the characterisation of heating robustness in a mouse. Device settings were optimised for treatment of a pancreas tumour and tested for varying circumstances. The impact of uncertainties in tissue property and perfusion values was evaluated using polynomial chaos expansion. Treatment quality and robustness were evaluated based on SAR and temperature distributions.Main results.The SAR distributions within the phantom are well-focused and can be adjusted to target any specific location. The focus size (full-width half-maximum) is a spheroid with diameters 9 mm (radially) and 20 mm (axially). The mouse model simulations show strong robustness against respiratory motion and intestine and stomach filling (∆T90≤0.14°C).Mouse positioning errors in the cranial-caudal direction lead to∆T90≤0.23°C. Uncertainties in tissue property and perfusion values were found to impact the treatment plan up to 0.56 °C (SD), with a variation onT90of 0.32 °C (1 SD).Significance.Our work shows that the pre-clinical phased-array system can provide adequate and robust locoregional heating of deep-seated target regions in mice. Using our software, robust treatment plans can be generated for pre-clinical hyperthermia research.
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Affiliation(s)
- Jort A Groen
- Amsterdam UMC location University of Amsterdam, Radiation Oncology, Amsterdam, The Netherlands
- Cancer Center Amsterdam, Cancer biology and immunology, Amsterdam, The Netherlands
- Cancer Center Amsterdam, Treatment and quality of life, Amsterdam, The Netherlands
| | - Johannes Crezee
- Amsterdam UMC location University of Amsterdam, Radiation Oncology, Amsterdam, The Netherlands
- Cancer Center Amsterdam, Cancer biology and immunology, Amsterdam, The Netherlands
- Cancer Center Amsterdam, Treatment and quality of life, Amsterdam, The Netherlands
| | - Hanneke W M van Laarhoven
- Cancer Center Amsterdam, Treatment and quality of life, Amsterdam, The Netherlands
- Amsterdam UMC location University of Amsterdam, Department of Medical Oncology, Amsterdam, The Netherlands
| | - Bram F Coolen
- Amsterdam UMC location University of Amsterdam, Department of Biomedical Engineering and Physics, Amsterdam, The Netherlands
| | - Gustav J Strijkers
- Amsterdam UMC location University of Amsterdam, Department of Biomedical Engineering and Physics, Amsterdam, The Netherlands
| | - Maarten F Bijlsma
- Cancer Center Amsterdam, Cancer biology and immunology, Amsterdam, The Netherlands
- Amsterdam UMC location University of Amsterdam, Center for Experimental and Molecular Medicine, Laboratory for Experimental Oncology and Radiobiology, Amsterdam, The Netherlands
- Cancer Center Amsterdam, Imaging and biomarkers, Amsterdam, the Netherlands
- Oncode Institute, Amsterdam, The Netherlands
| | - H Petra Kok
- Amsterdam UMC location University of Amsterdam, Radiation Oncology, Amsterdam, The Netherlands
- Cancer Center Amsterdam, Cancer biology and immunology, Amsterdam, The Netherlands
- Cancer Center Amsterdam, Treatment and quality of life, Amsterdam, The Netherlands
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Ji X, Fan X, Liu X, Gu J, Lu H, Luan Z, Liang J. Highly Elastic, Robust, and Efficient Hydrogel Solar Absorber against Harsh Environmental Impacts. Nano Lett 2024; 24:3498-3506. [PMID: 38440992 DOI: 10.1021/acs.nanolett.4c00456] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/06/2024]
Abstract
Solar distillation is a promising approach for addressing water scarcity, but relentless stress/strain perturbations induced by wind and waves would inevitably cause structural damage to solar absorbers. Despite notable advances in efficient solar absorbers, there have been no reports of compliant and robust solar absorbers withstanding practical mechanical impacts. Herein, an elastic and robust hydrogel absorber that exhibited a high level of evaporation performance was fabricated by introducing ion-coordinated MXene nanosheets as photothermal conversion units and mechanically enhanced fillers. The ion-coordinated MXene nanosheets acting as strong cross-linking points provided excellent elasticity and robustness to the hydrogel absorber. As a result, the evaporation rate of hydrogel absorber, with a high initial value of 2.61 kg m-2 h-1 under one sun irradiation, remained at 2.15 kg m-2 h-1 under a 100% tensile strain state and 2.40 kg m-2 h-1 after 10 000 stretching-releasing cycles. This continuous and stable water desalination approach provides a promising device for actual seawater distillation.
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Affiliation(s)
- Xinyi Ji
- School of Materials Science and Engineering, Nankai University, Tianjin 300350, P. R. China
| | - Xiangqian Fan
- School of Materials Science and Engineering, Nankai University, Tianjin 300350, P. R. China
- School of Energy and Power Engineering, North University of China, Taiyuan 030051, P. R. China
| | - Xue Liu
- School of Materials Science and Engineering, Nankai University, Tianjin 300350, P. R. China
| | - Jianfeng Gu
- School of Materials Science and Engineering, Nankai University, Tianjin 300350, P. R. China
| | - Haolin Lu
- School of Materials Science and Engineering, Nankai University, Tianjin 300350, P. R. China
| | - Zhaohui Luan
- School of Materials Science and Engineering, Nankai University, Tianjin 300350, P. R. China
| | - Jiajie Liang
- School of Materials Science and Engineering, Nankai University, Tianjin 300350, P. R. China
- Key Laboratory of Functional Polymer Materials of Ministry of Education, College of Chemistry, Nankai University, Tianjin 300350, P. R. China
- Smart Sensing Interdisciplinary Science Center, School of Materials Science and Engineering, Nankai University, Tianjin 300350, P. R. China
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Guo B, Lin J, Mo F, Ding Y, Zeng T, Liang H, Wang L, Chen X, Mo J, Li DS, Yang HY, Bai J. Robust and Corrosion-Resistant Overall Water Splitting Electrode Enabled by Additive Manufacturing. Small 2024:e2312216. [PMID: 38412417 DOI: 10.1002/smll.202312216] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/28/2023] [Revised: 02/15/2024] [Indexed: 02/29/2024]
Abstract
Electrolysis of water has emerged as a prominent area of research in recent years. As a promising catalyst support, copper foam is widely investigated for electrolytic water, yet the insufficient mechanical strength and corrosion resistance render it less suitable for harsh working conditions. To exploit high-performance catalyst supports, various metal supports are comprehensively evaluated, and Ti6 Al4 V (Ti64) support exhibited outstanding compression and corrosion resistance. With this in mind, a 3D porous Ti64 catalyst support is fabricated using the selective laser sintering (SLM) 3D printing technology, and a conductive layer of nickel (Ni) is coated to increase the electrical conductivity and facilitate the deposition of catalysts. Subsequently, Co0.8 Ni0.2 (CO3 )0.5 (OH)·0.11H2 O (CoNiCH) nanoneedles are deposited. The resulting porous Ti64/Ni/CoNiCH electrode displayed an impressive performance in the oxygen evolution reaction (OER) and reached 30 mA cm-2 at an overpotential of only 200 mV. Remarkably, even after being compressed at 15.04 MPa, no obvious structural deformation is observed, and the attenuation of its catalytic efficiency is negligible. Based on the computational analysis, the CoNiCH catalyst demonstrated superior catalytic activity at the Ni site in comparison to the Co site. Furthermore, the electrode reached 30 mA cm-2 at 1.75 V in full water splitting conditions and showed no significant performance degradation even after 60 h of continuous operation. This study presents an innovative approach to robust and corrosion-resistant catalyst design.
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Affiliation(s)
- Binbin Guo
- Shenzhen Key Laboratory for Additive Manufacturing of High-performance Materials, Department of Mechanical and Energy Engineering, Southern University of Science and Technology, Shenzhen, 518055, P. R. China
- Pillar of Engineering Product Development, Singapore University of Technology and Design, 8 Somapah Road, Singapore, 487372, Singapore
| | - Jie Lin
- Key Laboratory of Carbon Materials of Zhejiang Province, Wenzhou Key Lab of Advanced Energy Storage and Conversion, Zhejiang Province Key Lab of Leather Engineering, College of Chemistry and Materials Engineering, Wenzhou University, Wenzhou, Zhejiang, 325035, P. R. China
| | - Funian Mo
- Shenzhen Key Laboratory of Flexible Printed Electronics Technology Center, Harbin Institute of Technology, Shenzhen, 518055, P. R. China
| | - Yihong Ding
- Key Laboratory of Carbon Materials of Zhejiang Province, Wenzhou Key Lab of Advanced Energy Storage and Conversion, Zhejiang Province Key Lab of Leather Engineering, College of Chemistry and Materials Engineering, Wenzhou University, Wenzhou, Zhejiang, 325035, P. R. China
| | - Tianbiao Zeng
- Key Laboratory of Carbon Materials of Zhejiang Province, Wenzhou Key Lab of Advanced Energy Storage and Conversion, Zhejiang Province Key Lab of Leather Engineering, College of Chemistry and Materials Engineering, Wenzhou University, Wenzhou, Zhejiang, 325035, P. R. China
| | - Haowen Liang
- Shenzhen Key Laboratory for Additive Manufacturing of High-performance Materials, Department of Mechanical and Energy Engineering, Southern University of Science and Technology, Shenzhen, 518055, P. R. China
| | - Liping Wang
- Shenzhen Key Laboratory for Additive Manufacturing of High-performance Materials, Department of Mechanical and Energy Engineering, Southern University of Science and Technology, Shenzhen, 518055, P. R. China
| | - Xiaoteng Chen
- Shenzhen Key Laboratory for Additive Manufacturing of High-performance Materials, Department of Mechanical and Energy Engineering, Southern University of Science and Technology, Shenzhen, 518055, P. R. China
| | - Jiewen Mo
- Shenzhen Key Laboratory for Additive Manufacturing of High-performance Materials, Department of Mechanical and Energy Engineering, Southern University of Science and Technology, Shenzhen, 518055, P. R. China
| | - Dong-Sheng Li
- College of Materials and Chemical Engineering, Key Laboratory of Inorganic Nonmetallic Crystalline and Energy Conversion Materials, China Three Gorges University, Yichang, 443002, P. R. China
| | - Hui Ying Yang
- Pillar of Engineering Product Development, Singapore University of Technology and Design, 8 Somapah Road, Singapore, 487372, Singapore
| | - Jiaming Bai
- Shenzhen Key Laboratory for Additive Manufacturing of High-performance Materials, Department of Mechanical and Energy Engineering, Southern University of Science and Technology, Shenzhen, 518055, P. R. China
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Shen C, He Y, Qin J. Robust Multi-Dimensional Time Series Forecasting. Entropy (Basel) 2024; 26:92. [PMID: 38275500 DOI: 10.3390/e26010092] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/22/2023] [Revised: 01/19/2024] [Accepted: 01/19/2024] [Indexed: 01/27/2024]
Abstract
Large-scale and high-dimensional time series data are widely generated in modern applications such as intelligent transportation and environmental monitoring. However, such data contains much noise, outliers, and missing values due to interference during measurement or transmission. Directly forecasting such types of data (i.e., anomalous data) can be extremely challenging. The traditional method to deal with anomalies is to cut out the time series with anomalous value entries or replace the data. Both methods may lose important knowledge from the original data. In this paper, we propose a multidimensional time series forecasting framework that can better handle anomalous values: the robust temporal nonnegative matrix factorization forecasting model (RTNMFFM) for multi-dimensional time series. RTNMFFM integrates the autoregressive regularizer into nonnegative matrix factorization (NMF) with the application of the L2,1 norm in NMF. This approach improves robustness and alleviates overfitting compared to standard methods. In addition, to improve the accuracy of model forecasts on severely missing data, we propose a periodic smoothing penalty that keeps the sparse time slices as close as possible to the time slice with high confidence. Finally, we train the model using the alternating gradient descent algorithm. Numerous experiments demonstrate that RTNMFFM provides better robustness and better prediction accuracy.
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Affiliation(s)
- Chen Shen
- State Key Laboratory of Public Big Data, College of Computer Science and Technology, Guizhou University, Guiyang 550025, China
| | - Yong He
- State Key Laboratory of Public Big Data, College of Computer Science and Technology, Guizhou University, Guiyang 550025, China
| | - Jin Qin
- State Key Laboratory of Public Big Data, College of Computer Science and Technology, Guizhou University, Guiyang 550025, China
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Ohashi Y, Takahashi N, Sobue Y, Suzuki M, Sato R, Maeda M, Terabe K, Asai S, Imagama S. Well-controlled disease activity with drug treatment will not improve the frailty status of RA patients to robust state: A multicenter observational study (T-FLAG). Int J Rheum Dis 2024; 27:e14946. [PMID: 37975650 DOI: 10.1111/1756-185x.14946] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2023] [Revised: 10/07/2023] [Accepted: 10/12/2023] [Indexed: 11/19/2023]
Abstract
OBJECTIVES To investigate a plateau in treatment enhancement for improving the frailty status of rheumatoid arthritis (RA) patients. METHODS A total of 345 RA patients who were not robust in 2021 were assigned to the improved ("robust 2022," n = 51) and non-improved ("pre-frailty/frailty 2022," n = 294) groups. Factors associated with "robust 2022" were examined by logistic regression analysis. Patients were assigned to the stable (Follow-up mean DAS28-ESR in 2020 and 2021 < 3.2, n = 225) and unstable (≥3.2, n = 120) groups, which were further divided into the non-improved (stable: n = 180, unstable: n = 114) and improved (stable: n = 45, unstable: n = 6) groups. Factors influencing Japanese Cardiovascular Health Study (J-CHS) score were examined by multiple regression analysis. Changes over 2 years were compared between the non-improved and improved groups of the stable group. RESULTS The associated factor of "robust 2022" was the follow-up meanDAS28-ESR in 2020 and 2021 < 3.2 (i.e., stable state) (OR: 4.01). Follow-up mean DAS28-ESR in 2020 and 2021 was associated with J-CHS score (T = 2.536, p = .013) only in the unstable group. In the stable group, HAQ-DI was lower (2020: 0.32 vs. 0.16; 2021: 0.32 vs. 0.17; 2022: 0.32 vs. 0.21), and the proportion of J-CHS: Q4 (weakness) was lower (2020: 48.4 vs. 17.8%; 2021: 55.0 vs. 29.2%; 2022: 50.4 vs. 0%), in the improved group than in the non-improved group, whereas both groups maintained clinical and functional remission over 2 years. CONCLUSIONS Drug treatment to maintain well-controlled disease activity alone is insufficient for improving patients' frailty status after achieving treat-to-target goals, suggesting the need for multifaceted approaches.
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Affiliation(s)
- Yoshifumi Ohashi
- Department of Orthopedic Surgery, Nagoya University Graduate School of Medicine, Nagoya, Japan
- Department of Orthopedic Surgery, Yokkaichi Municipal Hospital, Yokkaichi, Japan
| | - Nobunori Takahashi
- Department of Orthopedic Surgery, Nagoya University Graduate School of Medicine, Nagoya, Japan
- Department of Orthopedic Surgery, Graduate School of Medicine, Aichi Medical University, Nagakute, Japan
| | - Yasumori Sobue
- Department of Orthopedic Surgery, Japan Red Cross, Aichi Medical Center, Nagoya Daiichi Hospital, Nagoya, Japan
| | - Mochihito Suzuki
- Department of Orthopedic Surgery, Nagoya University Graduate School of Medicine, Nagoya, Japan
- Department of Orthopedic Surgery, Japan Community Health Care Organization, Kani Tono Hospital, Gifu, Japan
| | - Ryo Sato
- Department of Orthopedic Surgery, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Masataka Maeda
- Department of Orthopedic Surgery, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Kenya Terabe
- Department of Orthopedic Surgery, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Shuji Asai
- Department of Orthopedic Surgery, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Shiro Imagama
- Department of Orthopedic Surgery, Nagoya University Graduate School of Medicine, Nagoya, Japan
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Hosseini M, Huang J, Williams MD, Gonzalez GA, Jiang X, Falkinham JO, Ducker WA. Robust and Transparent Silver Oxide Coating Fabricated at Room Temperature Kills Clostridioides difficile Spores, MRSA, and Pseudomonas aeruginosa. Microorganisms 2023; 12:83. [PMID: 38257910 PMCID: PMC10818310 DOI: 10.3390/microorganisms12010083] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2023] [Revised: 12/21/2023] [Accepted: 12/27/2023] [Indexed: 01/24/2024] Open
Abstract
Antimicrobial coatings can inhibit the transmission of infectious diseases when they provide a quick kill that is achieved long after the coating application. Here, we describe the fabrication and testing of a glass coating containing Ag2O microparticles that was prepared from sodium silicate at room temperature. The half-lives of both methicillin-resistant Staphylococcus aureus (MRSA) and Pseudomonas aeruginosa on this coating are only 2-4 min. The half-life of Clostridioides difficile spores is about 9-12 min, which is extremely short for a spore. Additional tests on MRSA demonstrate that the coating retains its antimicrobial activity after abrasion and that an increased loading of Ag2O leads to a shorter half-life. This coating combines the properties of optical transparency, robustness, fast kill, and room temperature preparation that are highly desirable for an antimicrobial coating.
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Affiliation(s)
- Mohsen Hosseini
- Department of Chemical Engineering, Center for Soft Matter and Biological Physics, Virginia Tech, Blacksburg, VA 24061, USA; (M.H.); (G.A.G.)
| | - Jinge Huang
- Department of Food, Nutrition, and Packaging Sciences, Clemson University, Clemson, SC 29634, USA; (J.H.); (X.J.)
| | - Myra D. Williams
- Department of Biological Sciences, Virginia Tech, Blacksburg, VA 24061, USA; (M.D.W.); (J.O.F.III)
| | - Gerardo Alexander Gonzalez
- Department of Chemical Engineering, Center for Soft Matter and Biological Physics, Virginia Tech, Blacksburg, VA 24061, USA; (M.H.); (G.A.G.)
| | - Xiuping Jiang
- Department of Food, Nutrition, and Packaging Sciences, Clemson University, Clemson, SC 29634, USA; (J.H.); (X.J.)
| | - Joseph O. Falkinham
- Department of Biological Sciences, Virginia Tech, Blacksburg, VA 24061, USA; (M.D.W.); (J.O.F.III)
| | - William A. Ducker
- Department of Chemical Engineering, Center for Soft Matter and Biological Physics, Virginia Tech, Blacksburg, VA 24061, USA; (M.H.); (G.A.G.)
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Shahsavari S, Moghimbeigi A, Kalhor R, Moghadas Jafari A, Bagherpour-kalo M, Yaseri M, Hosseini M. Zero-Inflated Count Regression Models in Solving Challenges Posed by Outlier-Prone Data; an Application to Length of Hospital Stay. Arch Acad Emerg Med 2023; 12:e13. [PMID: 38371448 PMCID: PMC10871051 DOI: 10.22037/aaem.v12i1.2074] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 02/20/2024]
Abstract
Introduction Ignoring outliers in data may lead to misleading results. Length of stay (LOS) is often considered a count variable with a high frequency of outliers. This study exemplifies the potential of robust methodologies in enhancing the accuracy and reliability of analyses conducted on skewed and outlier-prone count data of LOS. Methods The application of Zero-Inflated Poisson (ZIP) and robust Zero-Inflated Poisson (RZIP) models in solving challenges posed by outlier LOS data were evaluated. The ZIP model incorporates two components, tackling excess zeros with a zero-inflation component and modeling positive counts with a Poisson component. The RZIP model introduces the Robust Expectation-Solution (RES) algorithm to enhance parameter estimation and address the impact of outliers on the model's performance. Results Data from 254 intensive care unit patients were analyzed (62.2% male). Patients aged 65 or older accounted for 58.3% of the sample. Notably, 38.6% of patients exhibited zero LOS. The overall mean LOS was 5.89 (± 9.81) days, and 9.45% of cases displayed outliers. Our analysis using the RZIP model revealed significant predictors of LOS, including age, underlying comorbidities (p<0.001), and insurance status (p=0.013). Model comparison demonstrated the RZIP model's superiority over ZIP, as evidenced by lower Akaike information criteria (AIC) and Bayesians information criteria (BIC) values. Conclusions The application of the RZIP model allowed us to uncover meaningful insights into the factors influencing LOS, paving the way for more informed decision-making in hospital management.
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Affiliation(s)
- Saeed Shahsavari
- Department of Epidemiology and Biostatistics, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran
| | - Abbas Moghimbeigi
- Department of Biostatistics and Epidemiology, School of Health, Research Center for Health, Safety and Environment, Alborz University of Medical Sciences, Karaj, Iran
| | - Rohollah Kalhor
- Social Determinants of Health Research Center, Research Institute for Prevention of Non-Communicable Diseases, Qazvin University of Medical Sciences, Qazvin, Iran
| | - Ali Moghadas Jafari
- Tehran Medical Sciences Azad University, Farhikhtegan Hospital, Tehran, Iran
| | - Mehrdad Bagherpour-kalo
- Department of Epidemiology and Biostatistics, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran
| | - Mehdi Yaseri
- Department of Epidemiology and Biostatistics, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran
| | - Mostafa Hosseini
- Department of Epidemiology and Biostatistics, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran
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Creskey M, Li L, Ning Z, Fekete EE, Mayne J, Walker K, Ampaw A, Ben R, Zhang X, Figeys D. An economic and robust TMT labeling approach for high throughput proteomic and metaproteomic analysis. Proteomics 2023; 23:e2200116. [PMID: 36528842 DOI: 10.1002/pmic.202200116] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2022] [Revised: 12/13/2022] [Accepted: 12/14/2022] [Indexed: 12/23/2022]
Abstract
Multiplexed quantitative proteomics using tandem mass tag (TMT) is increasingly used in -omic study of complex samples. While TMT-based proteomics has the advantages of the higher quantitative accuracy, fewer missing values, and reduced instrument analysis time, it is limited by the additional reagent cost. In addition, current TMT labeling workflows involve repeated small volume pipetting of reagents in volatile solvents, which may increase the sample-to-sample variations and is not readily suitable for high throughput applications. In this study, we demonstrated that the TMT labeling procedures could be streamlined by using pre-aliquoted dry TMT reagents in a 96 well plate or 12-tube strip. As little as 50 μg dry TMT per channel was used to label 6-12 μg peptides, yielding high TMT labeling efficiency (∼99%) in both microbiome and mammalian cell line samples. We applied this workflow to analyze 97 samples in a study to evaluate whether ice recrystallization inhibitors improve the cultivability and activity of frozen microbiota. The results demonstrated tight sample clustering corresponding to groups and consistent microbiome responses to prebiotic treatments. This study supports the use of TMT reagents that are pre-aliquoted, dried, and stored for robust quantitative proteomics and metaproteomics in high throughput applications.
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Affiliation(s)
- Marybeth Creskey
- Regulatory Research Division, Centre for Oncology, Radiopharmaceuticals and Research, Biologic and Radiopharmaceutical Drugs Directorate, Health Products and Food Branch, Health Canada, Ottawa, Canada
| | - Leyuan Li
- School of Pharmaceutical Sciences, Faculty of Medicine, University of Ottawa, Ottawa, Canada
- Ottawa Institute of Systems Biology and Department of Biochemistry, Microbiology and Immunology, Faculty of Medicine, University of Ottawa, Ottawa, Canada
| | - Zhibin Ning
- School of Pharmaceutical Sciences, Faculty of Medicine, University of Ottawa, Ottawa, Canada
- Ottawa Institute of Systems Biology and Department of Biochemistry, Microbiology and Immunology, Faculty of Medicine, University of Ottawa, Ottawa, Canada
| | - Emily Ef Fekete
- Regulatory Research Division, Centre for Oncology, Radiopharmaceuticals and Research, Biologic and Radiopharmaceutical Drugs Directorate, Health Products and Food Branch, Health Canada, Ottawa, Canada
| | - Janice Mayne
- School of Pharmaceutical Sciences, Faculty of Medicine, University of Ottawa, Ottawa, Canada
- Ottawa Institute of Systems Biology and Department of Biochemistry, Microbiology and Immunology, Faculty of Medicine, University of Ottawa, Ottawa, Canada
| | - Krystal Walker
- School of Pharmaceutical Sciences, Faculty of Medicine, University of Ottawa, Ottawa, Canada
- Ottawa Institute of Systems Biology and Department of Biochemistry, Microbiology and Immunology, Faculty of Medicine, University of Ottawa, Ottawa, Canada
| | - Anna Ampaw
- Department of Chemistry, Faculty of Science, University of Ottawa, Ottawa, Canada
| | - Robert Ben
- Department of Chemistry, Faculty of Science, University of Ottawa, Ottawa, Canada
| | - Xu Zhang
- Regulatory Research Division, Centre for Oncology, Radiopharmaceuticals and Research, Biologic and Radiopharmaceutical Drugs Directorate, Health Products and Food Branch, Health Canada, Ottawa, Canada
- School of Pharmaceutical Sciences, Faculty of Medicine, University of Ottawa, Ottawa, Canada
| | - Daniel Figeys
- School of Pharmaceutical Sciences, Faculty of Medicine, University of Ottawa, Ottawa, Canada
- Ottawa Institute of Systems Biology and Department of Biochemistry, Microbiology and Immunology, Faculty of Medicine, University of Ottawa, Ottawa, Canada
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10
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Trimpin S, Inutan E, Coffinberger H, Hoang K, Yenchick F, Wager-Miller J, Pophristic M, Mackie K, McEwen CN. Instrumentation development, improvement, simplification, and miniaturization: The multifunctional plate source for use in mass spectrometry. Eur J Mass Spectrom (Chichester) 2023; 29:276-291. [PMID: 37999746 DOI: 10.1177/14690667231211486] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/25/2023]
Abstract
In remembrance of Prof. Dr Przybylski, we are presenting a vision towards his beloved mass spectrometry (MS) and its far-reaching promises outside of the academic laboratory. Sub-atmospheric pressure (AP) ionization MS is well positioned to make a step-change in direct ionization, a concept that allows sublimation/evaporation ionization and mass analyses of volatile and nonvolatile molecules from clean or dirty samples, directly, accurately, sensitively, and in a straightforward manner that has the potential to expand the field of MS into unchartered application areas. Contrary to ambient ionization MS, ionization commences in the sub-AP region of the mass spectrometer, important for practical and safety reasons, and offers inter alia, simplicity, speed, sensitivity, and robustness directly from real-world samples without cleanup. The plate source concept, presented here, provides an easy to use, rapid, and direct sample introduction from AP into the sub-AP of a mass spectrometer. Utilizing sub-AP ionization MS based on the plate source concept, small to large molecules from various environments that would be deemed too dirty for some direct MS methods are demonstrated. The new source concept can be expanded to include multiple ionization methods using the same plate source "front end" without the need to vent the mass spectrometer between the different methods, thus allowing ionization of more compounds on the same mass spectrometer for which any one ionization method may be insufficient. Examples such as fentanyl, gamma-hydroxybutyric acid, clozapine, 1-propionyllysergic acid, hydrocodone angiotensin I and II, myoglobin, and carbonic anhydrase are included.
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Affiliation(s)
- Sarah Trimpin
- Wayne State University, Detroit, MI, USA
- Research and Development, MSTM, LLC, Philadelphia, PA, USA
| | - Ellen Inutan
- Department of Chemistry, Mindanao State University-Illigan Institute of Technology, Illigan City, Philippines
| | - Hope Coffinberger
- Research and Development, MSTM, LLC, Philadelphia, PA, USA
- Department of Chemistry & Biochemistry, Saint Joseph's University, Philadelphia, PA, USA
| | - Khoa Hoang
- Research and Development, MSTM, LLC, Philadelphia, PA, USA
- Department of Chemistry & Biochemistry, Saint Joseph's University, Philadelphia, PA, USA
| | | | - James Wager-Miller
- Psychological and Brain Sciences Campus, Indiana University, Bloomington, IN, USA
| | - Milan Pophristic
- Research and Development, MSTM, LLC, Philadelphia, PA, USA
- Department of Chemistry & Biochemistry, Saint Joseph's University, Philadelphia, PA, USA
| | - Ken Mackie
- Psychological and Brain Sciences Campus, Indiana University, Bloomington, IN, USA
| | - Charles N McEwen
- Research and Development, MSTM, LLC, Philadelphia, PA, USA
- Department of Chemistry & Biochemistry, Saint Joseph's University, Philadelphia, PA, USA
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11
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Cao Y, Liu B, Pu J. Robust control for a tracked mobile robot based on a finite-time convergence zeroing neural network. Front Neurorobot 2023; 17:1242063. [PMID: 37799573 PMCID: PMC10547886 DOI: 10.3389/fnbot.2023.1242063] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2023] [Accepted: 08/22/2023] [Indexed: 10/07/2023] Open
Abstract
Introduction Since tracked mobile robot is a typical non-linear system, it has been a challenge to achieve the trajectory tracking of tracked mobile robots. A zeroing neural network is employed to control a tracked mobile robot to track the desired trajectory. Methods A new fractional exponential activation function is designed in this study, and the implicit derivative dynamic model of the tracked mobile robot is presented, termed finite-time convergence zeroing neural network. The proposed model is analyzed based on the Lyapunov stability theory, and the upper bound of the convergence time is given. In addition, the robustness of the finite-time convergence zeroing neural network model is investigated under different error disturbances. Results and discussion Numerical experiments of tracking an eight-shaped trajectory are conducted successfully, validating the proposed model for the trajectory tracking problem of tracked mobile robots. Comparative results validate the effectiveness and superiority of the proposed model for the kinematical resolution of tracked mobile robots even in a disturbance environment.
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Affiliation(s)
- Yuxuan Cao
- College of Power Engineering, Naval University of Engineering, Wuhan, China
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12
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Li Y, Bai Y, Wang Z, Gong Q, Li M, Bo Y, Xu H, Jiang G, Chi K. Exquisitely Constructing a Robust MOF with Dual Pore Sizes for Efficient CO 2 Capture. Molecules 2023; 28:6276. [PMID: 37687104 PMCID: PMC10488667 DOI: 10.3390/molecules28176276] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2023] [Revised: 08/17/2023] [Accepted: 08/18/2023] [Indexed: 09/10/2023] Open
Abstract
Developing metal-organic framework (MOF) adsorbents with excellent performance and robust stability is of critical importance to reduce CO2 emissions yet challenging. Herein, a robust ultra-microporous MOF, Cu(bpfb)(bdc), with mixed ligands of N, N'-(1,4-phenylene)diisonicotinamide (bpfb), and 1,4-dicarboxybenzene (bdc) was delicately constructed. Structurally, this material possesses double-interpenetrated frameworks formed by two staggered, independent frameworks, resulting in two types of narrow ultra-micropores of 3.4 × 5.0 and 4.2 × 12.8 Å2, respectively. The above structural properties make its highly selective separation at 273~298 K with a CO2 capacity of 71.0~86.2 mg/g. Its adsorption heat over CO2 and IAST selectivity were calculated to be 27 kJ/mol and 52.2, respectively. Remarkably, cyclic breakthrough experiments corroborate its impressive performance in CO2/N2 separation in not only dry but also 75% RH humid conditions. Molecular simulation reveals that C-H···OCO2 in the pores plays a pivotal role in the high selectivity of CO2 adsorption. These results point out the huge potential application of this material for CO2/N2 separation.
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Affiliation(s)
- Yanxi Li
- CNPC Petrochemical Research Institute Company Limited, Beijing 102206, China (M.L.)
| | - Yuhua Bai
- CNPC Petrochemical Research Institute Company Limited, Beijing 102206, China (M.L.)
- College of Chemical Engineering and Environment, China University of Petroleum-Beijing, Beijing 102249, China
| | - Zhuozheng Wang
- CNPC Petrochemical Research Institute Company Limited, Beijing 102206, China (M.L.)
| | - Qihan Gong
- CNPC Petrochemical Research Institute Company Limited, Beijing 102206, China (M.L.)
| | - Mengchen Li
- CNPC Petrochemical Research Institute Company Limited, Beijing 102206, China (M.L.)
| | - Yawen Bo
- CNPC Petrochemical Research Institute Company Limited, Beijing 102206, China (M.L.)
| | - Hua Xu
- CNPC Petrochemical Research Institute Company Limited, Beijing 102206, China (M.L.)
| | - Guiyuan Jiang
- College of Chemical Engineering and Environment, China University of Petroleum-Beijing, Beijing 102249, China
| | - Kebin Chi
- CNPC Petrochemical Research Institute Company Limited, Beijing 102206, China (M.L.)
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13
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Chong Y, Huo Y, Jiang S, Wang X, Zhang B, Liu T, Chen X, Han T, Smith P, Wang S, Jiang J. Machine learning of spectra-property relationship for imperfect and small chemistry data. Proc Natl Acad Sci U S A 2023; 120:e2220789120. [PMID: 37155896 PMCID: PMC10193941 DOI: 10.1073/pnas.2220789120] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2022] [Accepted: 03/16/2023] [Indexed: 05/10/2023] Open
Abstract
Machine learning (ML) is causing profound changes to chemical research through its powerful statistical and mathematical methodological capabilities. However, the nature of chemistry experiments often sets very high hurdles to collect high-quality data that are deficiency free, contradicting the need of ML to learn from big data. Even worse, the black-box nature of most ML methods requires more abundant data to ensure good transferability. Herein, we combine physics-based spectral descriptors with a symbolic regression method to establish interpretable spectra-property relationship. Using the machine-learned mathematical formulas, we have predicted the adsorption energy and charge transfer of the CO-adsorbed Cu-based MOF systems from their infrared and Raman spectra. The explicit prediction models are robust, allowing them to be transferrable to small and low-quality dataset containing partial errors. Surprisingly, they can be used to identify and clean error data, which are common data scenarios in real experiments. Such robust learning protocol will significantly enhance the applicability of machine-learned spectroscopy for chemical science.
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Affiliation(s)
- Yuanyuan Chong
- Hefei National Research Center for Physical Sciences at the Microscale, School of Chemistry and Materials Science, University of Science and Technology of China, Hefei230026, China
| | - Yaoyuan Huo
- Hefei National Research Center for Physical Sciences at the Microscale, School of Chemistry and Materials Science, University of Science and Technology of China, Hefei230026, China
| | - Shuang Jiang
- Hefei National Research Center for Physical Sciences at the Microscale, School of Chemistry and Materials Science, University of Science and Technology of China, Hefei230026, China
| | - Xijun Wang
- Hefei National Research Center for Physical Sciences at the Microscale, School of Chemistry and Materials Science, University of Science and Technology of China, Hefei230026, China
| | - Baichen Zhang
- Hefei National Research Center for Physical Sciences at the Microscale, School of Chemistry and Materials Science, University of Science and Technology of China, Hefei230026, China
| | - Tianfu Liu
- State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Science, Fuzhou350002, China
| | - Xin Chen
- GuSu Laboratory of Materials, Suzhou215123, China
| | - TianTian Han
- Hefei JiShu Quantum Technology Co. Ltd., Hefei230026, China
| | | | - Song Wang
- Hefei National Research Center for Physical Sciences at the Microscale, School of Chemistry and Materials Science, University of Science and Technology of China, Hefei230026, China
| | - Jun Jiang
- Hefei National Research Center for Physical Sciences at the Microscale, School of Chemistry and Materials Science, University of Science and Technology of China, Hefei230026, China
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14
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Abdulhamid A, El Najjar G, Alayesh A, Alghanmi A. Enhancing Strategic Learning Through the Implementation of Robust Process Improvement in a Specialized Tertiary Care Hospital. Glob J Qual Saf Healthc 2023; 6:42-54. [PMID: 37333759 PMCID: PMC10275630 DOI: 10.36401/jqsh-22-17] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/02/2022] [Revised: 02/09/2023] [Accepted: 02/13/2023] [Indexed: 06/20/2023]
Abstract
Introduction Performance improvement (PI) in healthcare is essential to improve health, patient experience, and reduce costs. PI projects became low, inconsistent and weakly-sustained in our hospital. The low number and low sustainability were scarcely in alignment with our strategic goal to become a high reliability organization (HRO). This was due to lack of standardized knowledge and ability to initiate and sustain PI projects. Therefore, a structured framework was developed, followed by the building of capacity and capability in the use of robust process improvement (RPI) amidst the COVID-19 pandemic. Methods A team of healthcare quality professionals collaborated with Hospital Performance Improvement-Press Ganey for hospital-wide quality improvement project. The team received training on RPI from Press Ganey and created the framework to use . This framework is based on the Institute for Healthcare Improvement Model for Improvement, Lean, Six Sigma, and FOCUS-PDSA (Find-Organize-Clarify-Understand-Select-Plan-Do-Study-Act). Thereafter, the team of internal coaches organized an RPI training course that consisted of 6 sessions, for clinical and nonclinical staff , using classroom and virtual sessions during the pandemic. This course was increased to eight sessions to avoid information overload. Process measures were collected using a survey to obtain feedback, whereas outcome measures were from the number of completed projects and their effects related to costs, access to care, waiting time, number of harms, and compliance. Results Participation and submission improved after three PDSA (Plan-Do-Study-Act) cycles. This resulted in an increased number of completed and sustained projects from 50 in 2019 to 94 in 2020 and continued to rise to 109 in 2021. There were 140 and 122 certified RPI coaches in 2020 and 2021, respectively. Although there was a decrease in the number of certified coaches in 2021, the number of completed projects was higher than in 2020. The overall effect of these completed projects by the third quarter of 2021 showed improvement in access to care by 39%, compliance to standards of care by 48%, satisfaction by 8%, and reduction in costs by 47,010 SAR, in waiting time of 170 hours, and in the number of harms by 89. Conclusion This quality improvement project led to enhanced capacity of staff as seen in the increased number of certified RPI coaches, thereby increasing the submission and completion of projects in 1 year. Its sustainability during the 2 succeeding years continued to enhance project completion and maintenance, bringing quality improvement benefits to the organization and the patients.
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Affiliation(s)
- Alliazer Abdulhamid
- Quality Management Department, King Faisal Specialist Hospital and Research Centre, Riyadh, Saudi Arabia
| | - Ghiwa El Najjar
- Quality and Patient Experience Section, Organ Transplant Center of Excellence (OTCoE), King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Aljohara Alayesh
- Quality Management Department, King Faisal Specialist Hospital and Research Centre, Riyadh, Saudi Arabia
| | - Arwa Alghanmi
- Quality Management Department, King Faisal Specialist Hospital and Research Centre, Riyadh, Saudi Arabia
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15
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Pistorio AL, Chung KC, Miller LE, Adams JE, Hammert WC. Protocol of a Multicenter Prospective Trial of Office-Based Carpal Tunnel Release With Ultrasound Guidance ( ROBUST). Cureus 2023; 15:e37479. [PMID: 37056220 PMCID: PMC10092058 DOI: 10.7759/cureus.37479] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/07/2023] [Indexed: 04/15/2023] Open
Abstract
Background Carpal tunnel release (CTR) is a common surgical procedure for patients with severe or refractory carpal tunnel syndrome (CTS) symptoms. Historically, CTR procedures have been performed in a hospital or an ambulatory surgery center (ASC). However, due to advancements in techniques, greater patient demand, and concerns about growing healthcare costs, there is a distinct trend toward performing CTR procedures in an office-based setting. Several small studies with limited follow-up duration have demonstrated the feasibility of CTR with ultrasound guidance (CTR-US) when performed in an office-based setting. The objective of this study is to evaluate the safety and effectiveness of office-based CTR-US in a large cohort of patients (n=140) with symptomatic CTS followed for two years post-treatment. Design and methods ROBUST is a prospective multicenter observational study in which 140 subjects at up to 12 sites in the United States will be treated with CTR-US in an office-based setting. The primary endpoint of the study is the change in the Boston Carpal Tunnel Questionnaire Symptom Severity Scale score. Secondary endpoints include time to return to normal daily activities, time to return to work among employed subjects, change in the Boston Carpal Tunnel Questionnaire Functional Status Scale score, change in the Michigan Hand Questionnaire overall and domain scores, change in the Numeric Pain Scale score, change in the EuroQoL-5 Dimension 5-Level score, global satisfaction scores, and the incidence of device or procedure-related adverse events. The primary analysis of study endpoints will occur three months post-treatment. Patient follow-up in this study will continue for two years. Conclusions A central institutional review board approved the study protocol, and a data safety monitoring board will provide study oversight. The authors plan to report study results at medical conferences and in peer-reviewed medical journals. The outcomes of ROBUST will provide physicians, patients, and payors with important safety and effectiveness data regarding the clinical utility of CTR-US when performed in an office setting.
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Affiliation(s)
- Ashley L Pistorio
- Department of Plastic Surgery, Kirk Kerkorian School of Medicine, University of Nevada, Las Vegas, USA
| | - Kevin C Chung
- Comprehensive Hand Center, Michigan Medicine, University of Michigan, Ann Arbor, USA
| | - Larry E Miller
- Department of Biostatistics, Miller Scientific, Johnson City, USA
| | - Julie E Adams
- Department of Orthopedic Surgery, University of Tennessee College of Medicine, Chattanooga, USA
| | - Warren C Hammert
- Department of Orthopedic Surgery, Division of Hand Surgery, Duke University Medical Center, Durham, USA
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16
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Kaser AN, Kaplan DM, Goette W, Kiselica AM. The impact of conventional versus robust norming on cognitive characterization and clinical classification of MCI and dementia. J Neuropsychol 2023; 17:108-124. [PMID: 36124357 PMCID: PMC10006397 DOI: 10.1111/jnp.12289] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2021] [Accepted: 07/22/2022] [Indexed: 11/30/2022]
Abstract
We examined the impact of conventional versus robust normative approaches on cognitive characterization and clinical classification of MCI versus dementia. The sample included participants from the National Alzheimer's Coordinating Center Uniform Data Set. Separate demographically adjusted z-scores for cognitive tests were derived from conventional (n = 4273) and robust (n = 602) normative groups. To assess the impact of deriving scores from a conventional versus robust normative group on cognitive characterization, we examined likelihood of having a low score on each neuropsychological test. Next, we created receiver operating characteristic (ROC) curves for the ability of normed scores derived from each normative group to differentiate between MCI (n = 3570) and dementia (n = 1564). We examined the impact of choice of normative group on classification accuracy by comparing sensitivity and specificity values and areas under the curves (AUC). Compared with using a conventional normative group, using a robust normative group resulted in a higher likelihood of low cognitive scores for individuals classified with MCI and dementia. Comparison of the classification accuracy for distinguishing MCI from dementia did not suggest a statistically significant advantage for either normative approach (Z = -0.29, p = .77; AUC = 0.86 for conventional and AUC = 0.86 for robust). In summary, these results indicate that using a robust normative group increases the likelihood of characterizing cognitive performance as low. However, there is not a clear advantage of using a robust over a conventional normative group when differentiating between MCI and dementia.
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Affiliation(s)
- Alyssa N. Kaser
- Department of Psychiatry, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - David M. Kaplan
- Department of Economics, University of Missouri, Columbia, Missouri, USA
| | - William Goette
- Department of Psychiatry, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Andrew M. Kiselica
- Department of Health Psychology, University of Missouri, Columbia, Missouri, USA
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17
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Franklin SL, Schuurmans M, Otikovs M, Borman PTS, van Osch MJP, Bos C. Arterial spin labeling using spatio-temporal encoding readout for robust perfusion imaging in inhomogenous magnetic fields. Magn Reson Med 2023; 89:1092-1101. [PMID: 36420871 PMCID: PMC10099794 DOI: 10.1002/mrm.29506] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2021] [Revised: 10/10/2022] [Accepted: 10/10/2022] [Indexed: 11/25/2022]
Abstract
PURPOSE To evaluate the feasibility of spatio-temporal encoding (SPEN) readout for pseudo-continuous ASL (pCASL) in brain, and its robustness to susceptibility artifacts as introduced by aneurysm clips. METHODS A 2D self-refocused T2 *-compensated hybrid SPEN scheme, with super-resolution reconstruction was implemented on a 1.5T Philips system. Q (=BWchirp *Tchirp ) was varied and, the aneurysm clip-induced artifact was evaluated in phantom (label-images) as well as in vivo (perfusion-weighted signal (PWS)-maps and temporal SNR (tSNR)). In vivo results were compared to gradient-echo EPI (GE-EPI) and spin-echo EPI (SE-EPI). The dependence of tSNR on TR was evaluated separately for SPEN and SE-EPI. SPEN with Q ˜ 75 encodes with the same off-resonance robustness as EPI. RESULTS The clip-induced artifact with SPEN decreased with increase in Q, and was smaller compared to SE-EPI and GE-EPI in vivo. tSNR decreased with Q and the tSNR of GE-EPI and SE-EPI corresponded to SPEN with a Q-value of approximately ˜85 and ˜108, respectively. In addition, SPEN perfusion images showed a higher tSNR (p < 0.05) for TR = 4000 ms compared to TR = 2100 ms, while SE-EPI did not. tSNR remained relatively stable when the time between SPEN-excitation and start of the next labeling-module was more than ˜1000 ms. CONCLUSION Feasibility of combining SPEN with pCASL imaging was demonstrated, enabling cerebral perfusion measurements with a higher robustness to field inhomogeneity (Q > 75) compared to SE-EPI and GE-EPI. However, the SPEN chirp-pulse saturates incoming blood, thereby reducing pCASL labeling efficiency of the next acquisition for short TRs. Future developments are needed to enable 3D scanning.
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Affiliation(s)
- Suzanne L Franklin
- Center for Image Sciences, University Medical Center Utrecht, Utrecht, The Netherlands.,C.J. Gorter Center for High Field MRI, Department of Radiology, Leiden University Medical Center, Leiden, The Netherlands
| | - Megan Schuurmans
- Center for Image Sciences, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Martins Otikovs
- Department of Chemical and Biological Physics, Weizmann Institute of Science, Rehovot, Israel
| | - Pim T S Borman
- Department of Radiotherapy, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Matthias J P van Osch
- C.J. Gorter Center for High Field MRI, Department of Radiology, Leiden University Medical Center, Leiden, The Netherlands.,Leiden Institute for Brain and Cognition, Leiden University, Leiden, The Netherlands
| | - Clemens Bos
- Center for Image Sciences, University Medical Center Utrecht, Utrecht, The Netherlands
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Hopkins M, Fil J, Jones EG, Furber S. BitBrain and Sparse Binary Coincidence (SBC) memories: Fast, robust learning and inference for neuromorphic architectures. Front Neuroinform 2023; 17:1125844. [PMID: 37025552 PMCID: PMC10071999 DOI: 10.3389/fninf.2023.1125844] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2022] [Accepted: 03/03/2023] [Indexed: 04/08/2023] Open
Abstract
We present an innovative working mechanism (the SBC memory) and surrounding infrastructure (BitBrain) based upon a novel synthesis of ideas from sparse coding, computational neuroscience and information theory that enables fast and adaptive learning and accurate, robust inference. The mechanism is designed to be implemented efficiently on current and future neuromorphic devices as well as on more conventional CPU and memory architectures. An example implementation on the SpiNNaker neuromorphic platform has been developed and initial results are presented. The SBC memory stores coincidences between features detected in class examples in a training set, and infers the class of a previously unseen test example by identifying the class with which it shares the highest number of feature coincidences. A number of SBC memories may be combined in a BitBrain to increase the diversity of the contributing feature coincidences. The resulting inference mechanism is shown to have excellent classification performance on benchmarks such as MNIST and EMNIST, achieving classification accuracy with single-pass learning approaching that of state-of-the-art deep networks with much larger tuneable parameter spaces and much higher training costs. It can also be made very robust to noise. BitBrain is designed to be very efficient in training and inference on both conventional and neuromorphic architectures. It provides a unique combination of single-pass, single-shot and continuous supervised learning; following a very simple unsupervised phase. Accurate classification inference that is very robust against imperfect inputs has been demonstrated. These contributions make it uniquely well-suited for edge and IoT applications.
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19
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Liu Y, Li C, Li J, Feng L. Joint User Scheduling and Hybrid Beamforming Design for Massive MIMO LEO Satellite Multigroup Multicast Communication Systems. Sensors (Basel) 2022; 22:6858. [PMID: 36146210 PMCID: PMC9503289 DOI: 10.3390/s22186858] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/10/2022] [Revised: 09/06/2022] [Accepted: 09/07/2022] [Indexed: 06/16/2023]
Abstract
In the satellite multigroup multicast communication systems based on the DVB-S2X standard, due to the limitation of the DVB-S2X frame structure, user scheduling and beamforming design have become the focus of academic research. In this work, we take the massive multi-input multi-output (MIMO) low earth orbit (LEO) satellite communication system adopting the DVB-S2X standard as the research scenario, and the LEO satellite adopts a uniform planar array (UPA) based on the fully connected hybrid structure. We focus on the coupling design of user scheduling and beamforming; meanwhile, the scheme design takes the influence of residual Doppler shift and phase disturbance on channel errors into account. Under the constraints of total transmission power and quality of service (QoS), we study the robust joint user scheduling and hybrid beamforming design aimed at maximizing the energy efficiency (EE). For this problem, we first adopt the hierarchical clustering algorithm to group users. Then, the semidefinite programming (SDP) algorithm and the concave convex process (CCCP) framework are applied to tackle the optimization of user scheduling and hybrid beamforming design. To handle the rank-one matrix constraint, the penalty iteration algorithm is proposed. To balance the performance and complexity of the algorithm, the user preselected step is added before joint design. Finally, to obtain the digital beamforming matrix and the analog beamforming matrix in a hybrid beamformer, the alternative optimization algorithm based on the majorization-minimization framework (MM-AltOpt) is proposed. Numerical simulation results show that the EE of the proposed joint user scheduling and beamforming design algorithm is higher than that of the traditional decoupling design algorithms.
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Affiliation(s)
- Yang Liu
- Graduate School, Space Engineering University, Beijing 101416, China
| | - Changqing Li
- Space Information School, Space Engineering University, Beijing 101416, China
| | - Jiong Li
- Space Information School, Space Engineering University, Beijing 101416, China
| | - Lu Feng
- Graduate School, Space Engineering University, Beijing 101416, China
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20
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Chen W, Wang W, Luong DX, Li JT, Granja V, Advincula PA, Ge C, Chyan Y, Yang K, Algozeeb WA, Higgs CF, Tour JM. Robust Superhydrophobic Surfaces via the Sand-In Method. ACS Appl Mater Interfaces 2022; 14:35053-35063. [PMID: 35862236 DOI: 10.1021/acsami.2c05076] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Superhydrophobic surfaces have gained sustained attention because of their extensive applications in the fields of self-cleaning, anti-icing, and drag reduction systems. Water droplets must have large apparent contact angle (CA) (>150°) and small CA hysteresis (<10°) on these surfaces. However, previous research usually involves complex fabrication strategies to modify the surface wettability. It is also challenging to maintain the temporal and mechanical stability of the delicate surface textures. Here, we develop a one-step solvent-free sand-in method to fabricate robust superhydrophobic surfaces directly atop various substrates with an apparent CA up to ∼163.8° and hysteresis less than 5°. The water repellency can withstand 100 Scotch tape peeling tests and remain stable after being stored under ambient humid conditions in Houston, Texas, for 18 months or being heated at 130 °C in air for 24 h. The superhydrophobic surfaces have excellent anti-icing ability, including a ∼2.6× longer water freezing time and ∼40% smaller ice adhesion strength with the temperature as low as -35 °C. Since the surface layers are fabricated by sanding the substrates with the powder additives, the surface damage can be repaired by a direct re-sanding treatment with the same powder additives. Further sand-in condition screenings broaden surface wettability from hydrophilic to superhydrophobic. The sand-in method induces the surface modification and the formation of the tribofilm. Surface and materials characterizations reveal that both microstructures and nanoscale asperities of the tribofilms contribute to the robust superhydrophobic features of sanded surfaces.
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Affiliation(s)
- Weiyin Chen
- Department of Chemistry, Rice University, 6100 Main Street, Houston, Texas 77005, United States
| | - Winston Wang
- Department of Chemistry, Rice University, 6100 Main Street, Houston, Texas 77005, United States
| | - Duy Xuan Luong
- Department of Chemistry, Rice University, 6100 Main Street, Houston, Texas 77005, United States
| | - John Tianci Li
- Department of Chemistry, Rice University, 6100 Main Street, Houston, Texas 77005, United States
| | - Victoria Granja
- Mechanical Engineering Department, Rice University, 6100 Main Street, Houston, Texas 77005, United States
| | - Paul A Advincula
- Department of Chemistry, Rice University, 6100 Main Street, Houston, Texas 77005, United States
| | - Chang Ge
- Applied Physics Programe, Rice University, 6100 Main Street, Houston, Texas 77005, United States
| | - Yieu Chyan
- Department of Chemistry, Rice University, 6100 Main Street, Houston, Texas 77005, United States
| | - Kaichun Yang
- Department of Chemistry, Rice University, 6100 Main Street, Houston, Texas 77005, United States
- Civil Engineering Department, Rice University, 6100 Main Street, Houston, Texas 77005, United States
| | - Wala A Algozeeb
- Department of Chemistry, Rice University, 6100 Main Street, Houston, Texas 77005, United States
| | - C Fred Higgs
- Mechanical Engineering Department, Rice University, 6100 Main Street, Houston, Texas 77005, United States
- Department of Bioengineering, Rice University, 6100 Main Street, Houston, Texas 77005, United States
| | - James M Tour
- Department of Chemistry, Rice University, 6100 Main Street, Houston, Texas 77005, United States
- Department of Materials Science and NanoEngineering, Rice University, 6100 Main Street, Houston, Texas 77005, United States
- Smalley-Curl Institute, Rice University, 6100 Main Street, Houston, Texas 77005, United States
- NanoCarbon Center and the Welch Institute for Advanced Materials, Rice University, 6100 Main Street, Houston, Texas 77005, United States
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21
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He Z, Li X, Wang H, Su F, Wang D, Yao D, Zheng Y. Synergistic Regulation of the Microstructure for Multifunctional Graphene Aerogels by a Dual Template Method. ACS Appl Mater Interfaces 2022; 14:22544-22553. [PMID: 35511465 DOI: 10.1021/acsami.2c00525] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
The performance of graphene aerogels (GAs) is based on the microstructure. However, GAs face a challenge of simultaneously controlling the size and alignment of pores strategically. Herein, we initially proposed a simple strategy to construct GAs with an adjustable structure based on the emulsion and ice dual template methods. Specifically, GAs with a honeycomb structure prepared by conventional freezing (CGAs) exhibited a high specific surface of 176 m2/g, superelasticity with a compressive strain of 95%, isotropic compression and thermal insulation performances, as well as an excellent absorption capacity of 150-550 g/g. Instead, the GAs with a bamboo-like network frozen by unidirectional freezing (UGAs) showed anisotropy in compression and thermal insulation behavior. Furthermore, UGAs exhibited incredible special stress (7.9 kPa cm3/mg) along the axial direction twice than that of the radial direction. Meanwhile, the apparent temperature of UGAs was only 45.6 °C when placed on a 120 °C hot stage along the radial direction. Remarkably, the properties of CGAs and UGAs were significantly improved with the adjustment of the microstructure.
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Affiliation(s)
- Zhongjie He
- School of Chemistry and Chemical Engineering, Northwestern Polytechnical University, Xi'an, Shaanxi 710129, P. R. China
| | - Xiaoqian Li
- School of Chemistry and Chemical Engineering, Northwestern Polytechnical University, Xi'an, Shaanxi 710129, P. R. China
| | - Hongni Wang
- School of Chemistry and Chemical Engineering, Northwestern Polytechnical University, Xi'an, Shaanxi 710129, P. R. China
| | - Fangfang Su
- School of Chemistry and Chemical Engineering, Northwestern Polytechnical University, Xi'an, Shaanxi 710129, P. R. China
| | - Dechao Wang
- School of Chemistry and Chemical Engineering, Northwestern Polytechnical University, Xi'an, Shaanxi 710129, P. R. China
| | - Dongdong Yao
- School of Chemistry and Chemical Engineering, Northwestern Polytechnical University, Xi'an, Shaanxi 710129, P. R. China
| | - Yaping Zheng
- School of Chemistry and Chemical Engineering, Northwestern Polytechnical University, Xi'an, Shaanxi 710129, P. R. China
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22
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Rao J, Mu J, Li F, Liu S. Infrared Small Target Detection Based on Weighted Local Coefficient of Variation Measure. Sensors (Basel) 2022; 22:3462. [PMID: 35591152 DOI: 10.3390/s22093462] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/01/2022] [Revised: 04/26/2022] [Accepted: 04/29/2022] [Indexed: 11/30/2022]
Abstract
Robust infrared (IR) small target detection is critical for infrared search and track (IRST) systems and is a challenging task for complicated backgrounds. Current algorithms have poor performance on complex backgrounds, and there is a high false alarm rate or even missed detection. To address this problem, a weighted local coefficient of variation (WLCV) is proposed for IR small target detection. This method consists of three stages. First, the preprocessing stage can enhance the original IR image and extract potential targets. Second, the detection stage consists of a background suppression module (BSM) and a local coefficient of variation (LCV) module. BSM uses a special three-layer window that combines the anisotropy of the target and differences in the grayscale distribution. LCV exploits the discrete statistical properties of the target grayscale. The weighted advantages of the two modules complement each other and greatly improve the effect of small target enhancement and background suppression. Finally, the weighted saliency map is subjected to adaptive threshold segmentation to extract the true target for detection. The experimental results show that the proposed method is more robust to different target sizes and background types than other methods and has a higher detection accuracy.
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23
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Baisero D, Schuster R, Plumptre AJ. Redefining and mapping global irreplaceability. Conserv Biol 2022; 36:e13806. [PMID: 34254360 DOI: 10.1111/cobi.13806] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/22/2020] [Revised: 07/01/2021] [Accepted: 07/09/2021] [Indexed: 06/13/2023]
Abstract
Irreplaceability is a concept used to describe how close a site is to being essential for achieving conservation targets. Current methods for measuring irreplaceability are based on representative combinations of sites, giving them an extrinsic nature and exponential computational requirements. Surrogate measures based on efficiency (complementarity) are often used as alternatives, but they were never intended for this purpose and do not measure irreplaceability. Current approaches used to estimate irreplaceability have key limitations. Some of these are a result of the tools used, but some are due to the nature of the current definition of irreplaceability. For irreplaceability to be stable and useful for conservation purposes and to resolve limitations, irreplaceability measures should adhere to five axioms; baseline coherence, monotonic responsiveness, proportional responsiveness, intrinsic stability, and bounded outputs. We designed a robust method for measuring a site's proximity to irreplaceability that adheres to these requirements and used it to develop the first systematic global map of irreplaceability based on data for terrestrial vertebrates (n = 29,837 species, >1 million grid cells). At least 3.5% of land surface was highly irreplaceable, and 47.6% of highly irreplaceable cells were contained in 12 countries. More generous thresholds of irreplaceability flag greater portions of land surface that would still be realistic to protect under current global objectives. Irreplaceable sites should form a critical component of any global conservation plan and should be part of the UN Convention on Biological Diversity's post2020 Global Biodiversity Framework strategy, forming part of the 30% protection by 2030 target that is gaining support. The reliable identification of irreplaceable sites will be crucial to halting extinctions.
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Affiliation(s)
- Daniele Baisero
- Key Biodiversity Areas Secretariat, c/o BirdLife International, Cambridge, UK
- Wildlife Conservation Society, Bronx, New York, USA
| | - Richard Schuster
- Department of Biology, Carleton University, Ottawa, Ontario, Canada
| | - Andrew J Plumptre
- Key Biodiversity Areas Secretariat, c/o BirdLife International, Cambridge, UK
- Conservation Science Group, Zoology Department, Cambridge University, Cambridge, UK
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24
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Jensch A, Lopes MB, Vinga S, Radde N. ROSIE: RObust Sparse ensemble for outlIEr detection and gene selection in cancer omics data. Stat Methods Med Res 2022; 31:947-958. [PMID: 35072570 PMCID: PMC9014683 DOI: 10.1177/09622802211072456] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
The extraction of novel information from omics data is a challenging task, in
particular, since the number of features (e.g. genes) often far exceeds the
number of samples. In such a setting, conventional parameter estimation leads to
ill-posed optimization problems, and regularization may be required. In
addition, outliers can largely impact classification accuracy. Here we introduce ROSIE, an ensemble classification approach, which combines
three sparse and robust classification methods for outlier detection and feature
selection and further performs a bootstrap-based validity check. Outliers of
ROSIE are determined by the rank product test using outlier rankings of all
three methods, and important features are selected as features commonly selected
by all methods. We apply ROSIE to RNA-Seq data from The Cancer Genome Atlas (TCGA) to classify
observations into Triple-Negative Breast Cancer (TNBC) and non-TNBC tissue
samples. The pre-processed dataset consists of 16,600 genes and more than 1,000 samples. We demonstrate that ROSIE selects important features
and outliers in a robust way. Identified outliers are concordant with the
distribution of the commonly selected genes by the three methods, and results
are in line with other independent studies. Furthermore, we discuss the
association of some of the selected genes with the TNBC subtype in other
investigations. In summary, ROSIE constitutes a robust and sparse procedure to
identify outliers and important genes through binary classification. Our
approach is ad hoc applicable to other datasets, fulfilling the overall goal of
simultaneously identifying outliers and candidate disease biomarkers to the
targeted in therapy research and personalized medicine frameworks.
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Affiliation(s)
- Antje Jensch
- Institute for Systems Theory and Automatic Control, 9149University of Stuttgart, Germany
| | - Marta B Lopes
- Center for Mathematics and Applications (CMA), NOVA School of Science and Technology, Caparica, Portugal.,NOVA Laboratory for Computer Science and Informatics (NOVA LINCS), NOVA School of Science and Technology, Caparica, Portugal
| | - Susana Vinga
- INESC-ID, Instituto Superior Técnico, 72971Universidade de Lisboa, Portugal.,IDMEC, Instituto Superior Técnico, Universidade de Lisboa, Portugal
| | - Nicole Radde
- Institute for Systems Theory and Automatic Control, 9149University of Stuttgart, Germany
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25
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Ren J, He J, Kong X, Li H. Robustness of ventilation systems in the control of walking-induced indoor fluctuations: Method development and case study. Build Simul 2022; 15:1645-1660. [PMID: 35194487 PMCID: PMC8854482 DOI: 10.1007/s12273-022-0888-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/28/2021] [Revised: 01/04/2022] [Accepted: 01/24/2022] [Indexed: 05/11/2023]
Abstract
Walking-induced fluctuations have a significant influence on indoor airflow and pollutant dispersion. This study developed a method to quantify the robustness of ventilation systems in the control of walking-induced fluctuation control. Experiments were conducted in a full-scale chamber with four different kinds of ventilation systems: ceiling supply and side return (CS), ceiling supply and ceiling return (CC), side supply and ceiling return (SC), and side supply and side return (SS). The measured temperature, flow and pollutant field data was (1) denoised by FFT filtering or wavelet transform; (2) fitted by a Gaussian function; (3) feature-extracted for the range and time scale disturbance; and then (4) used to calculate the range scale and time scale robustness for different ventilation systems with dimensionless equations developed in this study. The selection processes for FFT filtering and wavelet transform, FFT filter cut-off frequency, wavelet function, and decomposition layers are also discussed, as well as the threshold for wavelet denoising, which can be adjusted accordingly if the walking frequency or sampling frequency differs from that in other studies. The results show that for the flow and pollutant fields, the use of a ventilation system can increase the range scale robustness by 19.7%-39.4% and 10.0%-38.8%, respectively; and the SS system was 7.0%-25.7% more robust than the other three ventilation systems. However, all four kinds of ventilation systems had a very limited effect in controlling the time scale disturbance.
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Affiliation(s)
- Jianlin Ren
- School of Energy and Environmental Engineering, Hebei University of Technology, Tianjin, 300401 China
| | - Junjie He
- School of Energy and Environmental Engineering, Hebei University of Technology, Tianjin, 300401 China
| | - Xiangfei Kong
- School of Energy and Environmental Engineering, Hebei University of Technology, Tianjin, 300401 China
| | - Hongwan Li
- Department of Environmental Engineering Sciences, University of Florida, Gainesville, USA
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26
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Ghahremani-Nahr J, Kian R, Sabet E, Akbari V. A bi-objective blood supply chain model under uncertain donation, demand, capacity and cost: a robust possibilistic-necessity approach. Oper Res Int J 2022; 22:4685-4723. [PMCID: PMC9098156 DOI: 10.1007/s12351-022-00710-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/21/2021] [Revised: 04/04/2022] [Accepted: 04/11/2022] [Indexed: 05/20/2023]
Abstract
This paper addresses a multi-objective blood supply chain network design, considering economic and environmental aspects. The objective of this model is to simultaneously minimize a blood supply chain operational cost and its logistical carbon footprint. In order to embed the uncertainty of transportation costs, blood demand, capacity of facilities and carbon emission, a novel robust possibilistic-necessity optimization used regarding a hybrid optimistic-pessimistic form. For solving our bi-objective model, three multi-objective decision making approaches including LP-metric, Goal-Programming and Torabi- Hassini methods are examined. These approaches are assessed and ranked with respect to several attributes using a statistical test and TOPSIS method. Our proposed model can accommodate a wide range of decision-makers’ viewpoints with the normalized objective weights, both at the operational or strategic level. The trade-offs between the cost and carbon emission for each method has been depicted in our analyses and a Pareto frontier is determined, using a real case study data of 21 cities in the North-West of Iran considering a 12-month implementation time window.
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Affiliation(s)
| | - Ramez Kian
- Nottingham Business School, Nottingham Trent University, Nottingham, NG1 4FQ UK
| | - Ehsan Sabet
- Wolfson School of Mechanical, Electrical and Manufacturing Engineering, Loughborough University, Leicestershire, LE11 3TU UK
| | - Vahid Akbari
- Nottingham University Business School, University of Nottingham, Jubilee Campus, Nottingham, NG8 1BB UK
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27
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Chang CC, Wu CS, Tseng HY, Lee CY, Wu IC, Hsu CC, Chang HY, Chiu YF, Hsiung CA. Assessment of incident frailty hazard associated with depressive symptoms in a Taiwanese longitudinal study. Int Psychogeriatr 2022; 34:61-70. [PMID: 34275507 DOI: 10.1017/S1041610221000806] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
OBJECTIVES To estimate the risks of depressive symptoms for developing frailty, accounting for baseline robust or pre-frailty status. DESIGN An incident cohort study design. SETTING Community dwellers aged 55 years and above from urban and rural areas in seven regions in Taiwan. PARTICIPANTS A total of 2,717 participants from the Healthy Aging Longitudinal Study in Taiwan (HALST) were included. Subjects with frailty at baseline were excluded. The average follow-up period was 5.9 years. MEASUREMENTS Depressive symptoms were measured by the 20-item Center for Epidemiological Studies Depression (CES-D) Scale. Frailty was assessed using the Fried frailty measurement. Participants were stratified by baseline robust or pre-frailty status to reduce the confounding effects of the shared criteria between depressive symptoms and frailty. Overall and stratified survival analyses were conducted to assess risks of developing frailty as a result of baseline depressive symptoms. RESULTS One hundred individuals (3.7%) had depressive symptoms at baseline. Twenty-seven individuals (27.0%) with depressive symptoms developed frailty, whereas only 305 out of the 2,617 participants (11.7%) without depressive symptoms developed frailty during the follow-up period. After adjusting for covariates, depressive symptoms were associated with a 2.6-fold (95% CI 1.6, 4.2) increased hazard of incident frailty. The patterns of increased hazard were also observed when further stratified by baseline robust or pre-frailty status. CONCLUSIONS Depressive symptoms increased the risk of developing frailty among the older Asian population. The impact of late-life depressive symptoms on physical health was notable. These findings also replicated results from Western populations. Future policies on geriatric public health need to focus more on treatment and intervention against geriatric depressive symptoms to prevent incident frailty among older population.
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28
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Wang X, Liu J, Liu G. Diseases Detection of Occlusion and Overlapping Tomato Leaves Based on Deep Learning. Front Plant Sci 2021; 12:792244. [PMID: 34956290 PMCID: PMC8702556 DOI: 10.3389/fpls.2021.792244] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/10/2021] [Accepted: 11/09/2021] [Indexed: 05/02/2023]
Abstract
Background: In view of the existence of light shadow, branches occlusion, and leaves overlapping conditions in the real natural environment, problems such as slow detection speed, low detection accuracy, high missed detection rate, and poor robustness in plant diseases and pests detection technology arise. Results: Based on YOLOv3-tiny network architecture, to reduce layer-by-layer loss of information during network transmission, and to learn from the idea of inverse-residual block, this study proposes a YOLOv3-tiny-IRB algorithm to optimize its feature extraction network, improve the gradient disappearance phenomenon during network deepening, avoid feature information loss, and realize network multilayer feature multiplexing and fusion. The network is trained by the methods of expanding datasets and multiscale strategies to obtain the optimal weight model. Conclusion: The experimental results show that when the method is tested on the self-built tomato diseases and pests dataset, and while ensuring the detection speed (206 frame rate per second), the mean Average precision (mAP) under three conditions: (a) deep separation, (b) debris occlusion, and (c) leaves overlapping are 98.3, 92.1, and 90.2%, respectively. Compared with the current mainstream object detection methods, the proposed method improves the detection accuracy of tomato diseases and pests under conditions of occlusion and overlapping in real natural environment.
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Affiliation(s)
- Xuewei Wang
- Shandong Provincial University Laboratory for Protected Horticulture, Blockchain Laboratory of Agricultural Vegetables, Weifang University of Science and Technology, Weifang, China
| | - Jun Liu
- Shandong Provincial University Laboratory for Protected Horticulture, Blockchain Laboratory of Agricultural Vegetables, Weifang University of Science and Technology, Weifang, China
| | - Guoxu Liu
- College of Information and Control Engineering, Weifang University, Weifang, China
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29
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Zhao X, Peng Y, Cao X, Yu K, Lang H. Robust Superlubric Interface across Nano- and Micro-Scales Enabled by Fluoroalkylsilane Self-Assembled Monolayers and Atomically Thin Graphene. ACS Appl Mater Interfaces 2021; 13:56704-56717. [PMID: 34792342 DOI: 10.1021/acsami.1c20008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Robust superlubrication across nano- and microscales is highly desirable at the interface with asperities of different sizes in durable micro/nanoelectromechanical systems under a harsh environment. A novel method to fabricate superlubric interfaces across nano- and microscales is developed by combining a batch of surface modification with atomically thin graphene. The robust superlubric interface across nano- and microscales between hydrophobic 1H,1H,2H,2H-perfluorodecyltrichlorosilane (FDTS) self-assembly monolayers (SAMs) and graphene was achieved under high relative humidity, sliding speed, and contact pressure. The superlubric mechanisms at the interface of FDTS/graphene could be attributed to the following at different scales: the hydrophobicity of FDTS SAMs and graphene preventing the capillary interaction of the interfacial friction under high relative humidity; the high elastic modulus of graphene leading to small interfacial contact area; the compressing and orientating of FDTS SAMs decreasing interfacial shear strength under high contact pressure; the surface modification of FDTS molecules reducing the interfacial potential barriers when sliding on the atomically thin graphene. The robust superlubric interface across nano- and microscales reducing the friction at the complicated interfaces with asperities at different scales and improving the performance and durability have great potentials in the field of micro/nano mechanical systems.
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Affiliation(s)
- Xiuhua Zhao
- College of Mechanical Engineering, Donghua University, Shanghai 201620, P. R. China
| | - Yitian Peng
- College of Mechanical Engineering, Donghua University, Shanghai 201620, P. R. China
- Shanghai Collaborative Innovation Center for High Performance Fiber Composites, Donghua University, Shanghai 201620, P. R. China
| | - Xing'an Cao
- College of Mechanical Engineering, Donghua University, Shanghai 201620, P. R. China
| | - Kang Yu
- College of Mechanical Engineering, Donghua University, Shanghai 201620, P. R. China
| | - Haojie Lang
- College of Mechanical Engineering, Donghua University, Shanghai 201620, P. R. China
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30
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Burger DA, Schall R, van der Merwe S. A robust method for the assessment of average bioequivalence in the presence of outliers and skewness. Pharm Res 2021; 38:1697-1709. [PMID: 34676489 DOI: 10.1007/s11095-021-03110-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2021] [Accepted: 09/10/2021] [Indexed: 11/29/2022]
Abstract
PURPOSE In this paper, we propose a robust Bayesian method for the assessment of average bioequivalence based on data from conventional crossover studies. We evaluate and motivate empirically the need for robust methods in bioequivalence studies by comparing the results of robust and conventional statistical methods in a large data pool of bioequivalence studies. METHODS Robustness of the statistical methodology is achieved by replacing the normal distributions for residuals in the linear mixed model with skew-t distributions. In this way, the statistical model can accommodate skew and heavy-tailed data, particularly outliers, yielding robust statistical inference without the need for excluding outliers from the analysis. We performed a simulation study to investigate and compare the performance of the robust and conventional models. RESULTS Our study shows that in some trials, the distribution of residuals is skew and heavy-tailed. In the presence of outliers, the 90% confidence intervals for the ratio of geometric means tend to be narrower for the robust methods than for the conventional method. Our simulation study shows that the robust method has suitable frequentist properties and yields more precise confidence intervals and higher statistical power than the conventional maximum likelihood method when outliers are present in the data. CONCLUSIONS As a sensitivity analysis, we recommend the fit of robust models for handling outliers that are occasionally encountered in crossover design bioequivalence data.
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Affiliation(s)
| | - Robert Schall
- Department of Mathematical Statistics and Actuarial Science, University of the Free State, Bloemfontein, South Africa.,IQVIA, Biostatistics, Bloemfontein, South Africa
| | - Sean van der Merwe
- Department of Mathematical Statistics and Actuarial Science, University of the Free State, Bloemfontein, South Africa
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31
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Wanigatunga AA, Cai Y, Urbanek JK, Mitchell CM, Roth DL, Miller ER, Michos ED, Juraschek SP, Walston J, Xue QL, Appel LJ, Schrack JA. Objectively measured patterns of daily physical activity and phenotypic frailty. J Gerontol A Biol Sci Med Sci 2021; 77:1882-1889. [PMID: 34562073 DOI: 10.1093/gerona/glab278] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2021] [Indexed: 11/15/2022] Open
Abstract
BACKGROUND Self-reported low physical activity is a defining feature of phenotypic frailty but does not adequately capture physical activity performed throughout the day. This study examined associations between accelerometer-derived patterns of routine daily physical activity and frailty. METHODS Wrist accelerometer and frailty data from 638 participants (mean age 77 (SD=5.5) years; 44% women) were used to derive five physical activity metrics: active minutes/day, sedentary minutes/day, total activity counts/day, activity fragmentation (reciprocal of the average active bout length) and sedentary fragmentation (reciprocal of the average sedentary bout length). Robust, pre-frail and frail statuses were identified using the physical frailty phenotype defined as having 0, 1-2, or ≥3 of the following criterion: weight loss, exhaustion, slowness, self-reported low activity, and weakness. Frailty was collapsed into not frail (robust and prefrail) and frail, and each frailty criteria was dichotomized. Multiple logistic regression was used to model each accelerometer metric. Separate frailty criteria and interactions with age and sex were also examined. RESULTS With higher amounts and intensity of daily activity (more active minutes, fewer sedentary minutes, higher activity counts) and lower activity fragmentation, the odds of frailty were lower compared to robust/prefrail states (p<0.02 for all). For interactions, only an age by sedentary fragmentation interaction on the odds of frailty was observed (p=0.01). For each separate criteria, accelerometer metrics were associated with odds of slowness, low activity, and weakness. CONCLUSION Less favorable patterns of objectively measured daily physical activity are associated with frailty and the components of slowness, low self-reported activity, and weakness.
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Affiliation(s)
- Amal A Wanigatunga
- Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, USA.,Center on Aging and Health, Johns Hopkins University and Medical Institutions, Baltimore, Maryland, USA
| | - Yurun Cai
- Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, USA
| | - Jacek K Urbanek
- Division of Geriatric Medicine, Johns Hopkins School of Medicine, Baltimore, Maryland, USA
| | - Christine M Mitchell
- Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, USA.,Welch Center for Prevention, Epidemiology, and Clinical Research, Johns Hopkins University and Medical Institutions, Baltimore, Maryland, USA
| | - David L Roth
- Center on Aging and Health, Johns Hopkins University and Medical Institutions, Baltimore, Maryland, USA.,Division of Geriatric Medicine, Johns Hopkins School of Medicine, Baltimore, Maryland, USA
| | - Edgar R Miller
- Welch Center for Prevention, Epidemiology, and Clinical Research, Johns Hopkins University and Medical Institutions, Baltimore, Maryland, USA.,Division of General Internal Medicine, Johns Hopkins School of Medicine, Baltimore, Maryland, USA
| | - Erin D Michos
- Welch Center for Prevention, Epidemiology, and Clinical Research, Johns Hopkins University and Medical Institutions, Baltimore, Maryland, USA.,Division of Cardiology, Johns Hopkins School of Medicine, Baltimore, Maryland, USA
| | - Stephen P Juraschek
- Division of General Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School Teaching Hospital, Boston, Massachusetts, USA
| | - Jeremy Walston
- Division of Geriatric Medicine, Johns Hopkins School of Medicine, Baltimore, Maryland, USA
| | - Qian-Li Xue
- Center on Aging and Health, Johns Hopkins University and Medical Institutions, Baltimore, Maryland, USA.,Division of Geriatric Medicine, Johns Hopkins School of Medicine, Baltimore, Maryland, USA
| | - Lawrence J Appel
- Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, USA.,Welch Center for Prevention, Epidemiology, and Clinical Research, Johns Hopkins University and Medical Institutions, Baltimore, Maryland, USA.,Division of General Internal Medicine, Johns Hopkins School of Medicine, Baltimore, Maryland, USA
| | - Jennifer A Schrack
- Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, USA.,Center on Aging and Health, Johns Hopkins University and Medical Institutions, Baltimore, Maryland, USA
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32
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Xie H, Xu WH, Jia SH, Wu T. Tunable fabrication of biomimetic polypropylene nanopillars with robust superhydrophobicity and antireflectivity. Nanotechnology 2021; 32:395301. [PMID: 34126610 DOI: 10.1088/1361-6528/ac0b18] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/24/2020] [Accepted: 06/14/2021] [Indexed: 06/12/2023]
Abstract
The fine nanopillars on the natural cicada wing, which exhibits outstanding superhydrophobicity and anti-reflectivity, are carefully observed and analyzed. Here, a promising strategy by combining anodic aluminum oxide template and hot embossing is proposed for rapidly and efficiently mimicking the orderly and densely arranged nanopillars on the cicada wing surface to polypropylene (PP) surfaces. By adjusting the compression pressure, the nanostructures on the PP replica surface gradually evolve from nanoprotrusion-like features to nanopillar-like features so that a gradient wetting behavior from hydrophilicity to hydrophobicity and further to superhydrophobicity appears on the PP replica surfaces. Specifically, the biomimetic PP replica surface exhibits a contact angle of 159 ± 3° and a rolling angle of 8 ± 3° at a compression pressure of 15 MPa. Moreover, the biomimetic PP replica surface can stabilize its superhydrophobic state under a 1.96 kPa external pressure during the dynamic droplet impact. Besides robust dynamic superhydrophobicity, the biomimetic PP replica surface also demonstrated excellent anti-reflectivity because of the gradually changed effective refractive index. Therefore, the biomimetic PP replica inherits both the superhydrophobicity and anti-reflectivity of the natural cicada wing, which makes the products can effectively reduce the external damage when applied to agricultural films, dustproof films, and packaging materials.
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Affiliation(s)
- Heng Xie
- School of Chemistry and Chemical Engineering, Huazhong University of Science & Technology, Wuhan, Hubei, 430074, People's Republic of China
| | - Wen-Hua Xu
- Guangdong Provincial Key Laboratory of Technique and Equipment for Macromolecular Advanced Manufacturing, South China University of Technology, Guangzhou, Guangdong, 510640, People's Republic of China
| | - Shun-Heng Jia
- Guangdong Provincial Key Laboratory of Technique and Equipment for Macromolecular Advanced Manufacturing, South China University of Technology, Guangzhou, Guangdong, 510640, People's Republic of China
| | - Ting Wu
- Guangdong Provincial Key Laboratory of Technique and Equipment for Macromolecular Advanced Manufacturing, South China University of Technology, Guangzhou, Guangdong, 510640, People's Republic of China
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Zhu Z, Yasui T, Liu Q, Nagashima K, Takahashi T, Shimada T, Yanagida T, Baba Y. Fabrication of a Robust In 2O 3 Nanolines FET Device as a Biosensor Platform. Micromachines (Basel) 2021; 12:642. [PMID: 34072848 DOI: 10.3390/mi12060642] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/12/2021] [Revised: 05/26/2021] [Accepted: 05/30/2021] [Indexed: 01/14/2023]
Abstract
Field-effect transistors (FETs) are attractive biosensor platforms for rapid and accurate detection of various analytes through surface immobilization of specific bio-receptors. Since it is difficult to maintain the electrical stability of semiconductors of sensing channel under physiological conditions for long periods, passivation by a stable metal oxide dielectric layer, such as Al2O3 or HfO2, is currently used as a common method to prevent damage. However, protecting the sensing channel by passivation has the disadvantage that the distance between the target and the conductive channel increases, and the sensing signal will be degraded by Debye shielding. Even though many efforts use semiconductor materials directly as channels for biosensors, the electrical stability of semiconductors in the physiological environments has rarely been studied. In this work, an In2O3 nanolines FET device with high robustness in artificial physiological solution of phosphate buffered saline (PBS) was fabricated and used as a platform for biosensors without employing passivation on the sensing channel. The FET device demonstrated reproducibility with an average threshold voltage (VTH) of 5.235 V and a standard deviation (SD) of 0.382 V. We tested the robustness of the In2O3 nanolines FET device in PBS solution and found that the device had a long-term electrical stability in PBS with more than 9 days’ exposure. Finally, we demonstrated its applicability as a biosensor platform by testing the biosensing performance towards miR-21 targets after immobilizing the phosphonic acid terminated DNA probes. Since the surface immobilization of multiple bioreceptors is feasible, we demonstrate that the robust In2O3 FET device can be an excellent biosensor platform for biosensors.
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Santinha J, Matos C, Figueiredo M, Papanikolaou N. Improving performance and generalizability in radiogenomics: a pilot study for prediction of IDH1/2 mutation status in gliomas with multicentric data. J Med Imaging (Bellingham) 2021; 8:031905. [PMID: 33937440 PMCID: PMC8082292 DOI: 10.1117/1.jmi.8.3.031905] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2020] [Accepted: 04/13/2021] [Indexed: 12/22/2022] Open
Abstract
Purpose: Radiogenomics offers a potential virtual and noninvasive biopsy. However, radiogenomics models often suffer from generalizability issues, which cause a performance degradation on unseen data. In MRI, differences in the sequence parameters, manufacturers, and scanners make this generalizability issue worse. Such image acquisition information may be used to define different environments and select robust and invariant radiomic features associated with the clinical outcome that should be included in radiomics/radiogenomics models. Approach: We assessed 77 low-grade gliomas and glioblastomas multiform patients publicly available in TCGA and TCIA. Radiomics features were extracted from multiparametric MRI images (T1-weighted, contrast-enhanced T1-weighted, T2-weighted, and fluid-attenuated inversion recovery) and different regions-of-interest (enhancing tumor, nonenhancing tumor/necrosis, and edema). A method developed to find variables that are part of causal structures was used for feature selection and compared with an embedded feature selection approach commonly used in radiomics/radiogenomics studies, across two different scenarios: (1) leaving data from a center as an independent held-out test set and tuning the model with the data from the remaining centers and (2) use stratified partitioning to obtain the training and the held-out test sets. Results: In scenario (1), the performance of the proposed methodology and the traditional embedded method was AUC: 0.75 [0.25; 1.00] versus 0.83 [0.50; 1.00], Sens.: 0.67 [0.20; 0.93] versus 0.67 [0.20; 0.93], Spec.: 0.75 [0.30; 0.95] versus 0.75 [0.30; 0.95], and MCC: 0.42 [0.19; 0.68] versus 0.42 [0.19; 0.68] for center 1 as the held-out test set. The performance of both methods for center 2 as the held-out test set was AUC: 0.64 [0.36; 0.91] versus 0.55 [0.27; 0.82], Sens.: 0.00 [0.00; 0.73] versus 0.00 [0.00; 0.73], Spec.: 0.82 [0.52; 0.94] versus 0.91 [0.62; 0.98], and MCC: - 0.13 [ - 0.38 ; - 0.04 ] versus - 0.09 [ - 0.38 ; - 0.02 ] , whereas for center 3 was AUC: 0.80 [0.62; 0.95] versus 0.89 [0.56; 0.96], Sens.: 0.86 [0.48; 0.97] versus 0.86 [0.48; 0.97], Spec.: 0.72 [0.54; 0.85] versus 0.79 [0.61; 0.90], and MCC: 0.47 [0.41; 0.53] versus 0.55 [0.48; 0.60]. For center 4, the performance of both methods was AUC: 0.77 [0.51; 1.00] versus 0.75 [0.47; 0.97], Sens.: 0.53 [0.30; 0.75] versus 0.00 [0.00; 0.15], Spec.: 0.71 [0.35; 0.91] versus 0.86 [0.48; 0.97], and MCC: 0.23 [0.16; 0.31] versus. - 0.32 [ - 0.46 ; - 0.20 ] . In scenario (2), the performance of these methods was AUC: 0.89 [0.71; 1.00] versus 0.79 [0.58; 0.94], Sens.: 0.86 [0.80; 0.92] versus 0.43 [0.15; 0.74], Spec.: 0.87 [0.62; 0.96] versus 0.87 [0.62; 0.96], and MCC: 0.70 [0.60; 0.77] versus 0.33 [0.24; 0.42]. Conclusions: This proof-of-concept study demonstrated good performance by the proposed feature selection method in the majority of the studied scenarios, as it promotes robustness of features included in the models and the models' generalizability by making used imaging data of different scanners or with sequence parameters.
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Affiliation(s)
- João Santinha
- Clinical Computational Imaging Group, Champalimaud Research, Champalimaud Foundation, Lisboa, Portugal.,Universidade de Lisboa, Instituto de Telecomunicações, Instituto Superior Técnico, Lisboa, Portugal
| | - Celso Matos
- Champalimaud Clinical Center, Radiology Department, Champalimaud Foundation, Lisboa, Portugal
| | - Mário Figueiredo
- Universidade de Lisboa, Instituto de Telecomunicações, Instituto Superior Técnico, Lisboa, Portugal
| | - Nikolaos Papanikolaou
- Clinical Computational Imaging Group, Champalimaud Research, Champalimaud Foundation, Lisboa, Portugal
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De K, Banerjee J, Rajan SP, Chatterjee P, Chakrawarty A, Khan MA, Singh V, Dey AB. Development and Psychometric Validation of a New Scale for Assessment and Screening of Frailty Among Older Indians. Clin Interv Aging 2021; 16:537-547. [PMID: 33790548 PMCID: PMC8007478 DOI: 10.2147/cia.s292969] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2020] [Accepted: 02/16/2021] [Indexed: 12/12/2022] Open
Abstract
Background Frailty is a major challenge for healthcare systems in ageing societies. This dynamic state of health is a reflection of reduced reserve in various organ systems and enhanced vulnerability to stressors. Research in this area of geriatrics and gerontology is limited in low- and middle-income countries (LMICs) like India. This study is directed at development of a culturally appropriate and validated assessment scale for frailty among older Indians. Methods After extensive review of the literature on existing scales, a preliminary draft scale was formed. This draft was pre- and pilot-tested to check feasibility and modified accordingly. The final scale was validated on 107 older adults by confirmatory factor analysis and was named the Frailty Assessment and Screening Tool (FAST). The Fried’s frailty phenotype was also administered on the same 107 older adults and scores of both were co-related. Suitable cut-off scores were found for frail and pre-frail older adults. Results The final version of the FAST consisted of 14 questions pertaining to 10 domains. It has good reliability. Cronbach’s alpha co-efficient was 0.99; test–retest reliability was 0.97 and validity by confirmatory factor analysis was adequate. The Kaiser–CMeyer–Olkin (KMO) of sampling adequacy was 0.699, and Bartlett’s test of sphericity was significant (χ2 = 353.471, p < 0.001). FAST scores had a cut-off of ≥ 7/14 for frail and ≥ 5/14 for pre-frail elderly. Conclusion The FAST is a validated tool with good psychometric properties. It is expected that it will be helpful in screening pre-frail and frail older adults in India and other LMICs and guide in clinical decision making for intervention.
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Affiliation(s)
- Karishma De
- Department of Geriatric Medicine, All India Institute of Medical Sciences, New Delhi, India
| | - Joyita Banerjee
- Department of Geriatric Medicine, All India Institute of Medical Sciences, New Delhi, India
| | - Sreerag P Rajan
- Department of Geriatric Medicine, All India Institute of Medical Sciences, New Delhi, India
| | - Prasun Chatterjee
- Department of Geriatric Medicine, All India Institute of Medical Sciences, New Delhi, India
| | - Avinash Chakrawarty
- Department of Geriatric Medicine, All India Institute of Medical Sciences, New Delhi, India
| | - Maroof A Khan
- Department of Biostatistics, All India Institute of Medical Sciences, New Delhi, India
| | - Vishwajeet Singh
- Department of Geriatric Medicine, All India Institute of Medical Sciences, New Delhi, India
| | - Aparajit B Dey
- Department of Geriatric Medicine, All India Institute of Medical Sciences, New Delhi, India
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Abstract
Superhydrophobicity originating from the "lotus effect" enables novel applications such as self-cleaning, anti-fouling, anti-icing, anti-corrosion, and oil-water separation. However, their real-world applications are hindered by some main shortcomings, especially the organic solvent problem, complex chemical modification of nanoparticles, and poor mechanical stability of obtained surfaces. Here, we report for the first time the solvent-free, chemical modification-free, and mechanically, chemically, and UV robust superhydrophobic powder coatings. The coatings were fabricated by adding commercially available polytetrafluoroethylene (PTFE) particles into powder coatings and by following the regular powder-coating processing route. The formation of such superhydrophobic surfaces was attributed to PTFE particles, which hindered the microscale leveling of powder coatings during curing. Through adjusting the dosage of PTFE, the hydrophobicity of obtained coatings can be tuned in a large range (water contact angle from 92 to 162°). The superhydrophobic coatings exhibited remarkable mechanical robustness against abrasion because of the unique hierarchical micro/nanoscale roughness and low surface energy throughout the coating and the solid lubrication effect of PTFE particles. The coatings also have robustness against chemical corrosion and UV irradiation owing to high bonding energy and chemical inertness of PTFE. Moreover, the coatings show attractive performances including self-cleaning, anti-rain, anti-snow, and anti-icing. With these multifaceted features, such superhydrophobic coatings are promising for outdoor applications. This study also contributes to the preparation of robust superhydrophobic surfaces in an environmentally friendly way.
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Affiliation(s)
- Jinbao Huang
- Department of Chemical and Biochemical Engineering, Western University, London, Ontario N6A 5B9, Canada
| | - Marshall Yang
- Department of Chemical and Biochemical Engineering, Western University, London, Ontario N6A 5B9, Canada
| | - Hui Zhang
- Department of Chemical and Biochemical Engineering, Western University, London, Ontario N6A 5B9, Canada
| | - Jesse Zhu
- Department of Chemical and Biochemical Engineering, Western University, London, Ontario N6A 5B9, Canada
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Raes W, Knudde N, De Bruycker J, Dhaene T, Stevens N. Experimental Evaluation of Machine Learning Methods for Robust Received Signal Strength-Based Visible Light Positioning. Sensors (Basel) 2020; 20:E6109. [PMID: 33121055 DOI: 10.3390/s20216109] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/31/2020] [Revised: 10/16/2020] [Accepted: 10/22/2020] [Indexed: 11/17/2022]
Abstract
In this work, the use of Machine Learning methods for robust Received Signal Strength (RSS)-based Visible Light Positioning (VLP) is experimentally evaluated. The performance of Multilayer Perceptron (MLP) models and Gaussian processes (GP) is investigated when using relative RSS input features. The experimental set-up for the RSS-based VLP technology uses light-emitting diodes (LEDs) transmitting intensity modulated light and a single photodiode (PD) as a receiver. The experiments focus on achieving robustness to cope with unknown received signal strength modifications over time. Therefore, several datasets were collected, where per dataset either the LEDs transmitting power is modified or the PD aperture is partly obfuscated by dust particles. Two relative RSS schemes are investigated. The first scheme uses the maximum received light intensity to normalize the received RSS vector, while the second approach obtains RSS ratios by combining all possible unique pairs of received intensities. The Machine Learning (ML) methods are compared to a relative multilateration implementation. It is demonstrated that the adopted MLP and GP models exhibit superior performance and higher robustness when compared to the multilateration strategies. Furthermore, when comparing the investigated ML models, the GP model is proven to be more robust than the MLP for the considered scenarios.
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Lin D, Zhang X, Yuan S, Li Y, Xu F, Wang X, Li C, Wang H. Robust Waterborne Superhydrophobic Coatings with Reinforced Composite Interfaces. ACS Appl Mater Interfaces 2020; 12:48216-48224. [PMID: 32993286 DOI: 10.1021/acsami.0c14471] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Waterborne superhydrophobic coatings have attracted tremendous attention recently, but their practical applications are severely limited by hydrophobic instability and poor mechanical durability. Herein, a novel robust waterborne PTFE-CP&MgO-AOP superhydrophobic coating was successfully fabricated by reinforcing composite interfaces. Combined with the self-polymerization of dopamine and the in situ grown MgO, CNTs-polydopamine&MgO (CP&MgO) particles with improved interfacial compatibility were obtained. Through the cross-linking and hydrogen bonding interactions, phosphate networks (CP&MgO-AOP) with the aluminum orthophosphate (AOP) binder were formed during dehydration polymerization. The phosphate networks not only enhanced the interfacial interaction among CP&MgO to form coral-like structures but also strengthened the interfacial binding force between the waterborne polytetrafluoroethylene (PTFE) coating and the substrate. With the enhanced composite interfacial strength, the waterborne PTFE-CP&MgO-AOP coating exhibited excellent wear-resistance, which can withstand more than 1.27 × 105 abrasion cycles. Moreover, the chemical bonding between the functional groups of phosphate networks and metal substrate improved the adhesion strength from grade 5 to 1. Furthermore, the prepared coating surface with the reticular/coral-like composite structures can lock the stable gas layer to maintain excellent hydrophobic stability, even under the conditions of strong acidic/alkaline, high-temperature, xenon lamp irradiation, and mechanical wear. Thus, this study is expected to open new insights into interfacial enhancement of robust waterborne superhydrophobic coatings.
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Affiliation(s)
- Dan Lin
- School of Chemical Engineering and Technology and State Key Laboratory for Chemical Engineering, Tianjin University, Tianjin 300350, PR China
- Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), Tianjin University, Tianjin 300072, PR China
| | - Xiguang Zhang
- School of Chemical Engineering and Technology and State Key Laboratory for Chemical Engineering, Tianjin University, Tianjin 300350, PR China
- Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), Tianjin University, Tianjin 300072, PR China
| | - Sicheng Yuan
- School of Chemical Engineering and Technology and State Key Laboratory for Chemical Engineering, Tianjin University, Tianjin 300350, PR China
- Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), Tianjin University, Tianjin 300072, PR China
| | - Yuan Li
- School of Chemical Engineering and Technology and State Key Laboratory for Chemical Engineering, Tianjin University, Tianjin 300350, PR China
- Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), Tianjin University, Tianjin 300072, PR China
| | - Fei Xu
- School of Chemical Engineering and Technology and State Key Laboratory for Chemical Engineering, Tianjin University, Tianjin 300350, PR China
- Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), Tianjin University, Tianjin 300072, PR China
| | - Xiao Wang
- School of Chemical Engineering and Technology and State Key Laboratory for Chemical Engineering, Tianjin University, Tianjin 300350, PR China
- Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), Tianjin University, Tianjin 300072, PR China
| | - Cheng Li
- School of Chemical Engineering and Technology and State Key Laboratory for Chemical Engineering, Tianjin University, Tianjin 300350, PR China
- Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), Tianjin University, Tianjin 300072, PR China
| | - Huaiyuan Wang
- School of Chemical Engineering and Technology and State Key Laboratory for Chemical Engineering, Tianjin University, Tianjin 300350, PR China
- Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), Tianjin University, Tianjin 300072, PR China
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Parast L, Garcia TP, Prentice RL, Carroll RJ. Robust methods to correct for measurement error when evaluating a surrogate marker. Biometrics 2020; 78:9-23. [PMID: 33021738 DOI: 10.1111/biom.13386] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2019] [Revised: 09/16/2020] [Accepted: 09/30/2020] [Indexed: 11/27/2022]
Abstract
The identification of valid surrogate markers of disease or disease progression has the potential to decrease the length and costs of future studies. Most available methods that assess the value of a surrogate marker ignore the fact that surrogates are often measured with error. Failing to adjust for measurement error can erroneously identify a useful surrogate marker as not useful or vice versa. We investigate and propose robust methods to correct for the effect of measurement error when evaluating a surrogate marker using multiple estimators developed for parametric and nonparametric estimates of the proportion of treatment effect explained by the surrogate marker. In addition, we quantify the attenuation bias induced by measurement error and develop inference procedures to allow for variance and confidence interval estimation. Through a simulation study, we show that our proposed estimators correct for measurement error in the surrogate marker and that our inference procedures perform well in finite samples. We illustrate these methods by examining a potential surrogate marker that is measured with error, hemoglobin A1c, using data from the Diabetes Prevention Program clinical trial.
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Affiliation(s)
- Layla Parast
- RAND Corporation, Statistics Group, Santa Monica, California
| | - Tanya P Garcia
- Department of Biostatistics, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina
| | - Ross L Prentice
- Public Health Sciences Division, Fred Hutchinson Cancer Research Center, Seattle, Washington
| | - Raymond J Carroll
- Department of Statistics, Texas A&M University, College Station, Texas.,School of Mathematical and Physical Sciences, University of Technology Sydney, Broadway, NSW, Australia
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Wiik E, Jones JPG, Pynegar E, Bottazzi P, Asquith N, Gibbons J, Kontoleon A. Mechanisms and impacts of an incentive-based conservation program with evidence from a randomized control trial. Conserv Biol 2020; 34:1076-1088. [PMID: 32294257 DOI: 10.1111/cobi.13508] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/11/2019] [Revised: 02/06/2020] [Accepted: 02/07/2020] [Indexed: 06/11/2023]
Abstract
Conservation science needs more high-quality impact evaluations, especially ones that explore mechanisms of success or failure. Randomized control trials (RCTs) provide particularly robust evidence of the effectiveness of interventions (although they have been criticized as reductionist and unable to provide insights into mechanisms), but there have been few such experiments investigating conservation at the landscape scale. We explored the impact of Watershared, an incentive-based conservation program in the Bolivian Andes, with one of the few RCTs of landscape-scale conservation in existence. There is strong interest in such incentive-based conservation approaches as some argue they can avoid negative social impacts sometimes associated with protected areas. We focused on social and environmental outcomes based on responses from a household survey in 129 communities randomly allocated to control or treatment (conducted both at the baseline in 2010 and repeated in 2015-2016). We controlled for incomplete program uptake by combining standard RCT analysis with matching methods and investigated mechanisms by exploring intermediate and ultimate outcomes according to the underlying theory of change. Previous analyses, focused on single biophysical outcomes, showed that over its first 5 years Watershared did not slow deforestation or improve water quality at the landscape scale. We found that Watershared influenced some outcomes measured using the survey, but the effects were complex, and some were unexpected. We thus demonstrated how RCTs can provide insights into the pathways of impact, as well as whether an intervention has impact. This paper, one of the first registered reports in conservation science, demonstrates how preregistration can help make complex research designs more transparent, avoid cherry picking, and reduce publication bias.
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Affiliation(s)
- Emma Wiik
- School of Natural Sciences, Deiniol Road, Bangor University, Bangor, LL57 2UW, U.K
| | - Julia P G Jones
- School of Natural Sciences, Deiniol Road, Bangor University, Bangor, LL57 2UW, U.K
| | - Edwin Pynegar
- School of Natural Sciences, Deiniol Road, Bangor University, Bangor, LL57 2UW, U.K
- Fundacion Natura Bolivia, Calle Rio Totaitu 15, Santa Cruz de la Sierra, Bolivia
| | - Patrick Bottazzi
- School of Natural Sciences, Deiniol Road, Bangor University, Bangor, LL57 2UW, U.K
- Institute of Geography, University of Bern, Hallerstrasse 12, Bern, 3012, Switzerland
| | - Nigel Asquith
- Sustainability Science Program, Harvard Kennedy School, Cambridge, MA, 02138, U.S.A
- Cuencas Sustentables, Calle Rio Totaitu 15, Santa Cruz de la Sierra, Bolivia
| | - James Gibbons
- School of Natural Sciences, Deiniol Road, Bangor University, Bangor, LL57 2UW, U.K
| | - Andreas Kontoleon
- Department of Land Economy, University of Cambridge, 19 Silber Street, Cambridge, CB3 9EP, U.K
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Parast L, Griffin BA. Quantifying the bias due to observed individual confounders in causal treatment effect estimates. Stat Med 2020; 39:2447-2476. [PMID: 32388870 DOI: 10.1002/sim.8549] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2019] [Revised: 03/25/2020] [Accepted: 03/25/2020] [Indexed: 11/10/2022]
Abstract
It is often of interest to use observational data to estimate the causal effect of a target exposure or treatment on an outcome. When estimating the treatment effect, it is essential to appropriately adjust for selection bias due to observed confounders using, for example, propensity score weighting. Selection bias due to confounders occurs when individuals who are treated are substantially different from those who are untreated with respect to covariates that are also associated with the outcome. A comparison of the unadjusted, naive treatment effect estimate with the propensity score adjusted treatment effect estimate provides an estimate of the selection bias due to these observed confounders. In this article, we propose methods to identify the observed covariate that explains the largest proportion of the estimated selection bias. Identification of the most influential observed covariate or covariates is important in resource-sensitive settings where the number of covariates obtained from individuals needs to be minimized due to cost and/or patient burden and in settings where this covariate can provide actionable information to healthcare agencies, providers, and stakeholders. We propose straightforward parametric and nonparametric procedures to examine the role of observed covariates and quantify the proportion of the observed selection bias explained by each covariate. We demonstrate good finite sample performance of our proposed estimates using a simulation study and use our procedures to identify the most influential covariates that explain the observed selection bias in estimating the causal effect of alcohol use on progression of Huntington's disease, a rare neurological disease.
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Affiliation(s)
- Layla Parast
- Statistics Group, RAND Corporation, Santa Monica, California, USA
| | - Beth Ann Griffin
- Statistics Group, RAND Corporation, Santa Monica, California, USA
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Truong V, Duncan NW. Suggestions for improving the visualization of magnetic resonance spectroscopy voxels and spectra. R Soc Open Sci 2020; 7:200600. [PMID: 32968522 PMCID: PMC7481722 DOI: 10.1098/rsos.200600] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/09/2020] [Accepted: 07/13/2020] [Indexed: 05/10/2023]
Abstract
Magnetic resonance spectroscopy (MRS) has seen an increase in popularity as a method for studying the human brain. This approach is dependent on voxel localization and spectral quality, knowledge of which are essential for judging the validity and robustness of any analysis. As such, visualization plays a central role in appropriately communicating MRS studies. The quality of data visualization has been shown to be poor in a number of biomedical fields and so we sought to appraise this in MRS papers. To do this, we conducted a survey of the psychiatric single-voxel MRS literature. This revealed a generally low standard, with a significant proportion of papers not providing the voxel location and spectral quality information required to judge their validity or replicate the experiment. Based on this, we then present a series of suggestions for a minimal standard for MRS data visualization. The primary point of these is that both voxel location and MRS spectra be presented from all participants. Participant group membership should be indicated where more than one is included in the experiment (e.g. patients and controls). A set of suggested figure layouts that fulfil these requirements are presented with sample code provided to produce these (github.com/nwd2918/MRS-voxel-plot).
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Affiliation(s)
- Vuong Truong
- Graduate Institute of Mind, Brain and Consciousness, Taipei Medical University, Taipei, Taiwan
- Brain and Consciousness Research Centre, TMU-ShuangHo Hospital, New Taipei City, Taiwan
| | - Niall W. Duncan
- Graduate Institute of Mind, Brain and Consciousness, Taipei Medical University, Taipei, Taiwan
- Brain and Consciousness Research Centre, TMU-ShuangHo Hospital, New Taipei City, Taiwan
- Author for correspondence: Niall W. Duncan e-mail:
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Liu X, Zhao M, Xu Z, Xu H, Li S. Construction of a Robust Sphingomonas sp. Strain for Welan Gum Production via the Expression of Global Transcriptional Regulator IrrE. Front Bioeng Biotechnol 2020; 8:674. [PMID: 32695762 PMCID: PMC7338795 DOI: 10.3389/fbioe.2020.00674] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2020] [Accepted: 06/01/2020] [Indexed: 11/16/2022] Open
Abstract
Welan gum is a widely used microbial polysaccharide produced by Sphingomonas sp. However, an important factor hindering the expansion of its production is the maladaptation of strain to fermentation conditions. In this work, the global transcriptional regulator gene irre was selected as a stress-resistant element. And it was integrated into the site of the genomic carotene synthesis key enzyme gene crtB to construct a robust carotenoid-free welan gum producing strain. Fermentation with the recombinant strain effectively reduced the ethanol consumption and pigment content in the product. The tolerance temperature increased by 10°C without the need for controlling the pH. Under this fermentation condition, welan gum concentration could still reach 20.26 ± 0.25 g/L, which was 187.38% higher than that of the wild-type strain (7.05 ± 0.15 g/L). Transcriptome analysis showed that with the control of IrrE, more than 1000 genes that are involved in multiple pathways, including two-component system, bacterial chemotaxis, flagellar assembly, and cell cycle, exhibited changes at the transcriptional level and jointly allowed the strain to protect against environmental stresses.
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Affiliation(s)
- Xiaoliu Liu
- State Key Laboratory of Materials-Oriented Chemical Engineering, Nanjing, China.,College of Bioscience and Engineering, Hebei University of Economics and Business, Shijiazhuang, China
| | - Ming Zhao
- State Key Laboratory of Materials-Oriented Chemical Engineering, Nanjing, China.,College of Food Science and Light Industry, Nanjing Tech University, Nanjing, China
| | - Zheng Xu
- State Key Laboratory of Materials-Oriented Chemical Engineering, Nanjing, China.,College of Food Science and Light Industry, Nanjing Tech University, Nanjing, China
| | - Hong Xu
- State Key Laboratory of Materials-Oriented Chemical Engineering, Nanjing, China.,College of Food Science and Light Industry, Nanjing Tech University, Nanjing, China.,Jiangsu National Synergetic Innovation Center for Advanced Materials (SICAM), Nanjing, China
| | - Sha Li
- State Key Laboratory of Materials-Oriented Chemical Engineering, Nanjing, China.,College of Food Science and Light Industry, Nanjing Tech University, Nanjing, China
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Stiller AM, Usoro JO, Lawson J, Araya B, González-González MA, Danda VR, Voit WE, Black BJ, Pancrazio JJ. Mechanically Robust, Softening Shape Memory Polymer Probes for Intracortical Recording. Micromachines (Basel) 2020; 11:E619. [PMID: 32630553 PMCID: PMC7344527 DOI: 10.3390/mi11060619] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/21/2020] [Revised: 06/22/2020] [Accepted: 06/23/2020] [Indexed: 02/06/2023]
Abstract
While intracortical microelectrode arrays (MEAs) may be useful in a variety of basic and clinical scenarios, their implementation is hindered by a variety of factors, many of which are related to the stiff material composition of the device. MEAs are often fabricated from high modulus materials such as silicon, leaving devices vulnerable to brittle fracture and thus complicating device fabrication and handling. For this reason, polymer-based devices are being heavily investigated; however, their implementation is often difficult due to mechanical instability that requires insertion aids during implantation. In this study, we design and fabricate intracortical MEAs from a shape memory polymer (SMP) substrate that remains stiff at room temperature but softens to 20 MPa after implantation, therefore allowing the device to be implanted without aids. We demonstrate chronic recordings and electrochemical measurements for 16 weeks in rat cortex and show that the devices are robust to physical deformation, therefore making them advantageous for surgical implementation.
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Affiliation(s)
- Allison M. Stiller
- Department of Bioengineering, The University of Texas at Dallas, Richardson, TX 75080, USA; (J.O.U.); (J.L.); (B.A.); (W.E.V.); (B.J.B.); (J.J.P.)
| | - Joshua O. Usoro
- Department of Bioengineering, The University of Texas at Dallas, Richardson, TX 75080, USA; (J.O.U.); (J.L.); (B.A.); (W.E.V.); (B.J.B.); (J.J.P.)
| | - Jennifer Lawson
- Department of Bioengineering, The University of Texas at Dallas, Richardson, TX 75080, USA; (J.O.U.); (J.L.); (B.A.); (W.E.V.); (B.J.B.); (J.J.P.)
| | - Betsiti Araya
- Department of Bioengineering, The University of Texas at Dallas, Richardson, TX 75080, USA; (J.O.U.); (J.L.); (B.A.); (W.E.V.); (B.J.B.); (J.J.P.)
| | | | | | - Walter E. Voit
- Department of Bioengineering, The University of Texas at Dallas, Richardson, TX 75080, USA; (J.O.U.); (J.L.); (B.A.); (W.E.V.); (B.J.B.); (J.J.P.)
- Qualia, Inc., Dallas, TX 75252, USA;
- Department of Materials Science and Engineering, The University of Texas at Dallas, Richardson, TX 75080, USA
| | - Bryan J. Black
- Department of Bioengineering, The University of Texas at Dallas, Richardson, TX 75080, USA; (J.O.U.); (J.L.); (B.A.); (W.E.V.); (B.J.B.); (J.J.P.)
| | - Joseph J. Pancrazio
- Department of Bioengineering, The University of Texas at Dallas, Richardson, TX 75080, USA; (J.O.U.); (J.L.); (B.A.); (W.E.V.); (B.J.B.); (J.J.P.)
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45
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Yang J, Li J, Jia X, Li Y, Song H. Fabrication of Robust and Transparent Slippery Coating with Hot Water Repellency, Antifouling Property, and Corrosion Resistance. ACS Appl Mater Interfaces 2020; 12:28645-28654. [PMID: 32453938 DOI: 10.1021/acsami.0c06743] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Water-repellent coatings with low sliding angles for aqueous liquids are of great significance for practical applications. However, these coatings are susceptible to various types of damage during service and lose their effect. Herein, a robust and transparent slippery coating with extremely low water sliding angle was fabricated by covalently grafting polydimethylsiloxane (PDMS) brushes in a cross-linked skeleton of epoxy resin. Polyamidoamine G5.0 with 128 NH2 end groups was used as curing agent to induce the high cross-linking of the coating and the abundant PDMS brushes being grafted into it. Because of low surface energy and high mobility of PDMS brushes, the obtained coating exhibited a slippery performance for aqueous liquids (10 μL) with a sliding angle lower than 3° and a sliding speed as high as 1.16 mm/s. Even a 10 μL water droplet with temperature of 80 °C can slide off the coating at a low sliding angle (<5°). The strong intermolecular interactions of epoxy cross-linked skeleton endowed the coating with excellent physical and chemical stability. The sliding angle of the coating had no obvious change after heating at 120 °C for 100 h and placing outdoors for 7 months. The slippery performance was not affected by thumb press, knife scratching, high-speed friction, and water of different pH values. Furthermore, because of the excellent stability, antifouling performance, and corrosion resistance, the slippery coating can be applied to a variety of substrates, which makes the robust slippery coating have real potential for practical applications.
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Affiliation(s)
- Jin Yang
- School of Materials Science & Engineering, Shaanxi Key Laboratory of Green Preparation and Functionalization for Inorganic Materials, Shaanxi University of Science & Technology, Xi'an, Shaanxi 710021, P. R. China
| | - Jiayu Li
- Institute for Advanced Materials, School of Materials Science and Engineering, Jiangsu University, Zhenjiang 212013, P. R. China
| | - Xiaohua Jia
- School of Materials Science & Engineering, Shaanxi Key Laboratory of Green Preparation and Functionalization for Inorganic Materials, Shaanxi University of Science & Technology, Xi'an, Shaanxi 710021, P. R. China
| | - Yong Li
- School of Materials Science & Engineering, Shaanxi Key Laboratory of Green Preparation and Functionalization for Inorganic Materials, Shaanxi University of Science & Technology, Xi'an, Shaanxi 710021, P. R. China
| | - Haojie Song
- School of Materials Science & Engineering, Shaanxi Key Laboratory of Green Preparation and Functionalization for Inorganic Materials, Shaanxi University of Science & Technology, Xi'an, Shaanxi 710021, P. R. China
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Burton A, Offer K, Hardcastle N. A robust VMAT delivery solution for single-fraction lung SABR utilizing FFF beams minimizing dosimetric compromise. J Appl Clin Med Phys 2020; 21:299-304. [PMID: 32469150 PMCID: PMC7484828 DOI: 10.1002/acm2.12919] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2020] [Revised: 04/29/2020] [Accepted: 04/30/2020] [Indexed: 12/25/2022] Open
Abstract
Peripheral lung lesions treated with a single fraction of stereotactic ablative body radiotherapy (SABR) utilizing volumetric modulated arc therapy (VMAT) delivery and flattening filter‐free (FFF) beams represent a potentially high‐risk scenario for clinically significant dose blurring effects due to interplay between the respiratory motion of the lesion and dynamic multi‐leaf collimators (MLCs). The aim of this study was to determine an efficient means of developing low‐modulation VMAT plans in the Eclipse treatment planning system (v15.5, Varian Medical Systems, Palo Alto, USA) in order to minimize this risk, while maintaining dosimetric quality. The study involved 19 patients where an internal target volume (ITV) was contoured to encompass the entire range of tumor motion, and a planning target volume (PTV) created using a 5‐mm isotropic expansion of this contour. Each patient had seven plan variations created, with each rescaled to achieve the clinical planning goal for PTV coverage. All plan variations used the same field arrangement, and consisted of one dynamic conformal arc therapy (DCAT) plan, and six VMAT plans with varying degrees of modulation restriction, achieved through utilizing different combinations of the aperture shape controller (ASC) in the calculation parameters, and monitor unit (MU) objective during optimization. The dosimetric quality was assessed based on RTOG conformity indices (CI100/CI50), as well as adherence to dose–volume metrics used clinically at our institution. Plan complexity was assessed based on the modulation factor (MU/cGy) and the field edge metric. While VMAT plans with the least modulation restriction achieved the best dosimetry, it was found that there was no clinically significant trade‐off in terms of dose to organs at risk and conformity by reducing complexity. Furthermore, it was found that utilizing the ASC and MU objective could reduce plan complexity to near‐DCAT levels with improved dosimetry, which may be sufficiently robust to overcome the interplay effect.
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Affiliation(s)
- Alex Burton
- Peter MacCallum Cancer Centre, Melbourne, VIC, Australia
| | - Keith Offer
- Peter MacCallum Cancer Centre, Melbourne, VIC, Australia
| | - Nicholas Hardcastle
- Peter MacCallum Cancer Centre, Melbourne, VIC, Australia.,Centre for Medical Radiation Physics, University of Wollongong, Wollongong, NSW, Australia
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47
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Yang CY, Bialecka-Fornal M, Weatherwax C, Larkin JW, Prindle A, Liu J, Garcia-Ojalvo J, Süel GM. Encoding Membrane-Potential-Based Memory within a Microbial Community. Cell Syst 2020; 10:417-423.e3. [PMID: 32343961 PMCID: PMC7286314 DOI: 10.1016/j.cels.2020.04.002] [Citation(s) in RCA: 52] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2019] [Revised: 02/13/2020] [Accepted: 04/02/2020] [Indexed: 12/29/2022]
Abstract
Cellular membrane potential plays a key role in the formation and retrieval of memories in the metazoan brain, but it remains unclear whether such memory can also be encoded in simpler organisms like bacteria. Here, we show that single-cell-level memory patterns can be imprinted in bacterial biofilms by light-induced changes in the membrane potential. We demonstrate that transient optical perturbations generate a persistent and robust potassium-channel-mediated change in the membrane potential of bacteria within the biofilm. The light-exposed cells respond in an anti-phase manner, relative to unexposed cells, to both natural and induced oscillations in extracellular ion concentrations. This anti-phase response, which persists for hours following the transient optical stimulus, enables a direct single-cell resolution visualization of spatial memory patterns within the biofilm. The ability to encode robust and persistent membrane-potential-based memory patterns could enable computations within prokaryotic communities and suggests a parallel between neurons and bacteria.
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Affiliation(s)
- Chih-Yu Yang
- Division of Biological Sciences, University of California, San Diego, Pacific Hall Room 2225B, Mail Code 0347, 9500 Gilman Drive, La Jolla, CA 92093, USA
| | - Maja Bialecka-Fornal
- Division of Biological Sciences, University of California, San Diego, Pacific Hall Room 2225B, Mail Code 0347, 9500 Gilman Drive, La Jolla, CA 92093, USA
| | - Colleen Weatherwax
- Division of Biological Sciences, University of California, San Diego, Pacific Hall Room 2225B, Mail Code 0347, 9500 Gilman Drive, La Jolla, CA 92093, USA
| | - Joseph W Larkin
- Division of Biological Sciences, University of California, San Diego, Pacific Hall Room 2225B, Mail Code 0347, 9500 Gilman Drive, La Jolla, CA 92093, USA
| | - Arthur Prindle
- Division of Biological Sciences, University of California, San Diego, Pacific Hall Room 2225B, Mail Code 0347, 9500 Gilman Drive, La Jolla, CA 92093, USA; Department of Biochemistry and Molecular Genetics, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA
| | - Jintao Liu
- Division of Biological Sciences, University of California, San Diego, Pacific Hall Room 2225B, Mail Code 0347, 9500 Gilman Drive, La Jolla, CA 92093, USA; Center for Infectious Diseases Research and Tsinghua-Peking Center for Life Sciences, School of Medicine, Tsinghua University, Beijing 100084, People's Republic of China
| | - Jordi Garcia-Ojalvo
- Department of Experimental and Health Sciences, Universitat Pompeu Fabra, Barcelona Biomedical Research Park, Barcelona 08003, Spain
| | - Gürol M Süel
- Division of Biological Sciences, University of California, San Diego, Pacific Hall Room 2225B, Mail Code 0347, 9500 Gilman Drive, La Jolla, CA 92093, USA; San Diego Center for Systems Biology, University of California, San Diego, La Jolla, CA 92093, USA; Center for Microbiome Innovation, University of California, San Diego, La Jolla, CA 92093-0380, USA.
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48
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Bonett DG, Price RM. Interval estimation for linear functions of medians in within-subjects and mixed designs. Br J Math Stat Psychol 2020; 73:333-346. [PMID: 31062346 DOI: 10.1111/bmsp.12171] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/18/2018] [Revised: 03/10/2019] [Indexed: 06/09/2023]
Abstract
The currently available distribution-free confidence interval for a difference of medians in a within-subjects design requires an unrealistic assumption of identical distribution shapes. A confidence interval for a general linear function of medians is proposed for within-subjects designs that do not assume identical distribution shapes. The proposed method can be combined with a method for linear functions of independent medians to provide a confidence interval for a linear function of medians in mixed designs. Simulation results show that the proposed methods have good small-sample properties under a wide range of conditions. The proposed methods are illustrated with examples, and R functions that implement the new methods are provided.
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Affiliation(s)
- Douglas G Bonett
- Department of Psychology, University of California, Santa Cruz, California, USA
| | - Robert M Price
- Department of Mathematics and Statistics, East Tennessee State University, Johnson City, Tennessee, USA
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49
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Sun J, Lu G, Zhou J, Yuan Y, Zhu X, Nie J. Robust Physically Linked Double-Network Ionogel as a Flexible Bimodal Sensor. ACS Appl Mater Interfaces 2020; 12:14272-14279. [PMID: 32129592 DOI: 10.1021/acsami.0c01472] [Citation(s) in RCA: 55] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
To date, ionogel sensors have aroused the extensive interest as an alternative to hydrogel sensors, as they are promising materials to solve the problems of easy drying and easy freezing. However, the weak mechanical properties of ionogels have seriously hindered their large-scale application. Herein, a robust physically linked double-network ionogel (DN ionogel) was fabricated via interpenetrating a poly(hydroxyethyl acrylate) network into an agarose network in 1-ethyl-3-methylimidazolium chloride. The DN ionogel possessed good mechanical properties, high transparency, extreme temperature tolerance, and excellent self-adhesion. The superior electromechanical properties render the DN ionogel as a perfect candidate to be utilized as a strain sensor to monitor various human activities. In addition, the DN ionogel exhibited reasonably high sensitivity to temperature. Therefore, it is believed that this high performance strain-temperature bimodal sensor offers a promising prospect in flexible intelligent electronics.
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Affiliation(s)
- Jingxian Sun
- State Key Laboratory of Chemical Resource Engineering, Beijing University of Chemical Technology, Beijing 100029, P. R. China
| | - Guoqiang Lu
- State Key Laboratory of Chemical Resource Engineering, Beijing University of Chemical Technology, Beijing 100029, P. R. China
| | - Jiulei Zhou
- State Key Laboratory of Chemical Resource Engineering, Beijing University of Chemical Technology, Beijing 100029, P. R. China
| | - Yixin Yuan
- State Key Laboratory of Chemical Resource Engineering, Beijing University of Chemical Technology, Beijing 100029, P. R. China
| | - Xiaoqun Zhu
- State Key Laboratory of Chemical Resource Engineering, Beijing University of Chemical Technology, Beijing 100029, P. R. China
| | - Jun Nie
- State Key Laboratory of Chemical Resource Engineering, Beijing University of Chemical Technology, Beijing 100029, P. R. China
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50
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Huang Y, Zhou XH. Identification of the optimal treatment regimen in the presence of missing covariates. Stat Med 2020; 39:353-368. [PMID: 31774192 PMCID: PMC6954309 DOI: 10.1002/sim.8407] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2018] [Revised: 09/25/2019] [Accepted: 09/27/2019] [Indexed: 12/25/2022]
Abstract
Covariates associated with treatment-effect heterogeneity can potentially be used to make personalized treatment recommendations towards best clinical outcomes. Methods for treatment-selection rule development that directly maximize treatment-selection benefits have attracted much interest in recent years, due to the robustness of these methods to outcome modeling. In practice, the task of treatment-selection rule development can be further complicated by missingness in data. Here, we consider the identification of optimal treatment-selection rules for a binary disease outcome when measurements of an important covariate from study participants are partly missing. Under the missing at random assumption, we develop a robust estimator of treatment-selection rules under the direct-optimization paradigm. This estimator targets the maximum selection benefits to the population under correct specification of at least one mechanism from each of the two sets-missing data or conditional covariate distribution, and treatment assignment or disease outcome model. We evaluate and compare performance of the proposed estimator with alternative direct-optimization estimators through extensive simulation studies. We demonstrate the application of the proposed method through a real data example from an Alzheimer's disease study for developing covariate combinations to guide the treatment of Alzheimer's disease.
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Affiliation(s)
- Ying Huang
- Vaccine & Infectious Diseases Division, Fred Hutchinson Cancer Research Center, Seattle, WA, 98109, USA,Correspondence;
| | - Xiao-Hua Zhou
- Department of Biostatistics, Peking University, Beijing, China,Correspondence;
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