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Islam R, Majurski P, Kwon J, Sharma A, Tummala SRSK. Benchmarking Artificial Neural Network Architectures for High-Performance Spiking Neural Networks. Sensors (Basel) 2024; 24:1329. [PMID: 38400487 PMCID: PMC10892219 DOI: 10.3390/s24041329] [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: 01/22/2024] [Revised: 02/13/2024] [Accepted: 02/17/2024] [Indexed: 02/25/2024]
Abstract
Organizations managing high-performance computing systems face a multitude of challenges, including overarching concerns such as overall energy consumption, microprocessor clock frequency limitations, and the escalating costs associated with chip production. Evidently, processor speeds have plateaued over the last decade, persisting within the range of 2 GHz to 5 GHz. Scholars assert that brain-inspired computing holds substantial promise for mitigating these challenges. The spiking neural network (SNN) particularly stands out for its commendable power efficiency when juxtaposed with conventional design paradigms. Nevertheless, our scrutiny has brought to light several pivotal challenges impeding the seamless implementation of large-scale neural networks (NNs) on silicon. These challenges encompass the absence of automated tools, the need for multifaceted domain expertise, and the inadequacy of existing algorithms to efficiently partition and place extensive SNN computations onto hardware infrastructure. In this paper, we posit the development of an automated tool flow capable of transmuting any NN into an SNN. This undertaking involves the creation of a novel graph-partitioning algorithm designed to strategically place SNNs on a network-on-chip (NoC), thereby paving the way for future energy-efficient and high-performance computing paradigms. The presented methodology showcases its effectiveness by successfully transforming ANN architectures into SNNs with a marginal average error penalty of merely 2.65%. The proposed graph-partitioning algorithm enables a 14.22% decrease in inter-synaptic communication and an 87.58% reduction in intra-synaptic communication, on average, underscoring the effectiveness of the proposed algorithm in optimizing NN communication pathways. Compared to a baseline graph-partitioning algorithm, the proposed approach exhibits an average decrease of 79.74% in latency and a 14.67% reduction in energy consumption. Using existing NoC tools, the energy-latency product of SNN architectures is, on average, 82.71% lower than that of the baseline architectures.
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Affiliation(s)
- Riadul Islam
- Department of Computer Science and Electrical Engineering, University of Maryland, Baltimore County, Baltimore, MD 21250, USA
| | - Patrick Majurski
- Department of Computer Science and Electrical Engineering, University of Maryland, Baltimore County, Baltimore, MD 21250, USA
| | - Jun Kwon
- Department of Computer Science and Electrical Engineering, University of Maryland, Baltimore County, Baltimore, MD 21250, USA
| | - Anurag Sharma
- Department of Computer Science and Electrical Engineering, University of Maryland, Baltimore County, Baltimore, MD 21250, USA
| | - Sri Ranga Sai Krishna Tummala
- Department of Computer Science and Electrical Engineering, University of Maryland, Baltimore County, Baltimore, MD 21250, USA
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Okada JI, Washio T, Sugiura S, Hisada T. Low-energy defibrillation using a base-apex epicardial electrode. Pacing Clin Electrophysiol 2023; 46:1325-1332. [PMID: 37830313 DOI: 10.1111/pace.14832] [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] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/25/2023] [Revised: 08/17/2023] [Accepted: 09/10/2023] [Indexed: 10/14/2023]
Abstract
BACKGROUND Current implantable cardioverter defibrillators (ICDs) require electric conduction with high voltage and high energy, which can impair cardiac function and induce another malignant arrhythmia. As a result, there has been a demand for an ICD that can effectively operate with lower energy to mitigate the risks of a strong electric shock. METHODS A pair of sheet-shaped electrodes covering the heart were analyzed in three configurations (top-bottom, left-right, and front-back) using a heart simulator. We also varied the distance between the two electrodes (clearance) to identify the electrode shape with the lowest defibrillation threshold (DFT). We also investigated the ICD shock waveform, shock direction, and the effect of the backside insulator of the electrode. RESULTS The DFT was high when the clearance was too small and the DFT was high even when the clearance was too large, suggesting that an optimal value clearance. The top-bottom electrodes with optimal clearance showed the lowest DFT when the biphasic shocks set the top electrode to a high potential first and then the bottom electrode was set to a high potential. An interval between a first shock waveform and a second shock waveform should be provided for low-energy defibrillation. Because the insulator prevents unnecessary current flow to the backside, the DFT of the electrodes with insulators is less than those without insulators. CONCLUSION Painless defibrillation using sheet-shaped electrodes on the epicardium is predicated on the basis of results using a heart simulator.
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Affiliation(s)
- Jun-Ichi Okada
- UT-Heart Inc., Setagaya-ku, Tokyo, Japan
- Graduate School of Frontier Sciences, The University of Tokyo, Kashiwa-shi, Chiba, Japan
| | - Takumi Washio
- UT-Heart Inc., Setagaya-ku, Tokyo, Japan
- Graduate School of Frontier Sciences, The University of Tokyo, Kashiwa-shi, Chiba, Japan
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Glavin D, Grua EM, Nakamura CA, Scazufca M, Ribeiro Dos Santos E, Wong GHY, Hollingworth W, Peters TJ, Araya R, Van de Ven P. Patient Health Questionnaire-9 Item Pairing Predictiveness for Prescreening Depressive Symptomatology: Machine Learning Analysis. JMIR Ment Health 2023; 10:e48444. [PMID: 37856186 PMCID: PMC10623235 DOI: 10.2196/48444] [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] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/24/2023] [Revised: 07/13/2023] [Accepted: 08/10/2023] [Indexed: 10/20/2023] Open
Abstract
BACKGROUND Anhedonia and depressed mood are considered the cardinal symptoms of major depressive disorder. These are the first 2 items of the Patient Health Questionnaire (PHQ)-9 and comprise the ultrabrief PHQ-2 used for prescreening depressive symptomatology. The prescreening performance of alternative PHQ-9 item pairings is rarely compared with that of the PHQ-2. OBJECTIVE This study aims to use machine learning (ML) with the PHQ-9 items to identify and validate the most predictive 2-item depressive symptomatology ultrabrief questionnaire and to test the generalizability of the best pairings found on the primary data set, with 6 external data sets from different populations to validate their use as prescreening instruments. METHODS All 36 possible PHQ-9 item pairings (each yielding scores of 0-6) were investigated using ML-based methods with logistic regression models. Their performances were evaluated based on the classification of depressive symptomatology, defined as PHQ-9 scores ≥10. This gave each pairing an equal opportunity and avoided any bias in item pairing selection. RESULTS The ML-based PHQ-9 items 2 and 4 (phq2&4), the depressed mood and low-energy item pairing, and PHQ-9 items 2 and 8 (phq2&8), the depressed mood and psychomotor retardation or agitation item pairing, were found to be the best on the primary data set training split. They generalized well on the primary data set test split with area under the curves (AUCs) of 0.954 and 0.946, respectively, compared with an AUC of 0.942 for the PHQ-2. The phq2&4 had a higher AUC than the PHQ-2 on all 6 external data sets, and the phq2&8 had a higher AUC than the PHQ-2 on 3 data sets. The phq2&4 had the highest Youden index (an unweighted average of sensitivity and specificity) on 2 external data sets, and the phq2&8 had the highest Youden index on another 2. The PHQ-2≥2 cutoff also had the highest Youden index on 2 external data sets, joint highest with the phq2&4 on 1, but its performance fluctuated the most. The PHQ-2≥3 cutoff had the highest Youden index on 1 external data set. The sensitivity and specificity achieved by the phq2&4 and phq2&8 were more evenly balanced than the PHQ-2≥2 and ≥3 cutoffs. CONCLUSIONS The PHQ-2 did not prove to be a more effective prescreening instrument when compared with other PHQ-9 item pairings. Evaluating all item pairings showed that, compared with alternative partner items, the anhedonia item underperformed alongside the depressed mood item. This suggests that the inclusion of anhedonia as a core symptom of depression and its presence in ultrabrief questionnaires may be incompatible with the empirical evidence. The use of the PHQ-2 to prescreen for depressive symptomatology could result in a greater number of misclassifications than alternative item pairings.
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Affiliation(s)
- Darragh Glavin
- Department of Electronic and Computer Engineering, University of Limerick, Limerick, Ireland
- Health Research Institute, University of Limerick, Limerick, Ireland
| | - Eoin Martino Grua
- Department of Electronic and Computer Engineering, University of Limerick, Limerick, Ireland
- Health Research Institute, University of Limerick, Limerick, Ireland
| | - Carina Akemi Nakamura
- Departamento de Psiquiatria, Faculdade de Medicina, Universidade de Sao Paulo, Sao Paulo, Brazil
| | - Marcia Scazufca
- Departamento de Psiquiatria, Faculdade de Medicina, Universidade de Sao Paulo, Sao Paulo, Brazil
- Instituto de Psiquiatria, Hospital das Clinicas, Faculdade de Medicina, Universidade de Sao Paulo, Sao Paulo, Brazil
| | | | - Gloria H Y Wong
- Department of Social Work and Social Administration, University of Hong Kong, Pok Fu Lam, China (Hong Kong)
- Sau Po Centre on Ageing, University of Hong Kong, Pok Fu Lam, China (Hong Kong)
| | | | - Tim J Peters
- Bristol Dental School, University of Bristol, Bristol, United Kingdom
| | - Ricardo Araya
- Centre for Global Mental Health, Institute of Psychiatry, King's College London, London, United Kingdom
| | - Pepijn Van de Ven
- Department of Electronic and Computer Engineering, University of Limerick, Limerick, Ireland
- Health Research Institute, University of Limerick, Limerick, Ireland
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Defoort-Levkov GRN, Bahm A, Philipp P. Ultralow-energy amorphization of contaminated silicon samples investigated by molecular dynamics. Beilstein J Nanotechnol 2023; 14:834-849. [PMID: 37560350 PMCID: PMC10407782 DOI: 10.3762/bjnano.14.68] [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] [Figures] [Subscribe] [Scholar Register] [Received: 03/24/2023] [Accepted: 07/13/2023] [Indexed: 08/11/2023]
Abstract
Ion beam processes related to focused ion beam milling, surface patterning, and secondary ion mass spectrometry require precision and control. Quality and cleanliness of the sample are also crucial factors. Furthermore, several domains of nanotechnology and industry use nanoscaled samples that need to be controlled to an extreme level of precision. To reduce the irradiation-induced damage and to limit the interactions of the ions with the sample, low-energy ion beams are used because of their low implantation depths. Yet, low-energy ion beams come with a variety of challenges. When such low energies are used, the residual gas molecules in the instrument chamber can adsorb on the sample surface and impact the ion beam processes. In this paper we pursue an investigation on the effects of the most common contaminant, water, sputtered by ultralow-energy ion beams, ranging from 50 to 500 eV and covering the full range of incidence angles, using molecular dynamics simulations with the ReaxFF potential. We show that the expected sputtering yield trends are maintained down to the lowest sputtering yields. A region of interest with low damage is obtained for incidence angles around 60° to 75°. We also demonstrate that higher energies induce a larger removal of the water contaminant and, at the same time, induce an increased amorphization, which leads to a trade-off between sample cleanliness and damage.
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Affiliation(s)
- Grégoire R N Defoort-Levkov
- Advanced Instrumentation for Nano-Analytics (AINA), Materials Research and Technology Department (MRT), Luxembourg Institute of Science and Technology (LIST), 4422 Belvaux, Luxembourg
- University of Luxembourg, 4365 Esch-sur-Alzette, Luxembourg
| | - Alan Bahm
- Thermo Fisher Scientific, Hillsboro, OR, 97124, USA
| | - Patrick Philipp
- Advanced Instrumentation for Nano-Analytics (AINA), Materials Research and Technology Department (MRT), Luxembourg Institute of Science and Technology (LIST), 4422 Belvaux, Luxembourg
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Pires PC, Fernandes M, Nina F, Gama F, Gomes MF, Rodrigues LE, Meirinho S, Silvestre S, Alves G, Santos AO. Innovative Aqueous Nanoemulsion Prepared by Phase Inversion Emulsification with Exceptional Homogeneity. Pharmaceutics 2023; 15:1878. [PMID: 37514064 PMCID: PMC10384498 DOI: 10.3390/pharmaceutics15071878] [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: 05/29/2023] [Revised: 06/22/2023] [Accepted: 06/30/2023] [Indexed: 07/30/2023] Open
Abstract
Formulating low-solubility or low-permeability drugs is a challenge, particularly with the low administration volumes required in intranasal drug delivery. Nanoemulsions (NE) can solve both issues, but their production and physical stability can be challenging, particularly when a high proportion of lipids is necessary. Hence, the aim of the present work was to develop a NE with good solubilization capacity for lipophilic drugs like simvastatin and able to promote the absorption of drugs with low permeability like fosphenytoin. Compositions with high proportion of two lipids were screened and characterized. Surprisingly, one of the compositions did not require high energy methods for high droplet size homogeneity. To better understand formulation factors important for this feature, several related compositions were evaluated, and their relative cytotoxicity was screened. Optimized compositions contained a high proportion of propylene glycol monocaprylate NF, formed very homogenous NE using a low-energy phase inversion method, solubilized simvastatin at high drug strength, and promoted a faster intranasal absorption of the hydrophilic prodrug fosphenytoin. Hence, a new highly homogeneous NE obtained by a simple low-energy method was successfully developed, which is a potential alternative for industrial application for the solubilization and protection of lipophilic actives, as well as (co-)administration of hydrophilic molecules.
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Affiliation(s)
- Patrícia C Pires
- CICS-UBI-Health Sciences Research Centre, University of Beira Interior, Av. Infante D. Henrique, 6200-506 Covilhã, Portugal
- Department of Pharmaceutical Technology, Faculty of Pharmacy, University of Coimbra, 3000-548 Coimbra, Portugal
- Associated Laboratory for Green Chemistry (LAQV) of the Network of Chemistry and Technology (REQUIMTE), Faculty of Pharmacy, University of Coimbra, 3000-548 Coimbra, Portugal
| | - Mariana Fernandes
- CICS-UBI-Health Sciences Research Centre, University of Beira Interior, Av. Infante D. Henrique, 6200-506 Covilhã, Portugal
- Faculty of Health Sciences, University of Beira Interior, Av. Infante D. Henrique, 6200-506 Covilhã, Portugal
| | - Francisca Nina
- CICS-UBI-Health Sciences Research Centre, University of Beira Interior, Av. Infante D. Henrique, 6200-506 Covilhã, Portugal
- Faculty of Health Sciences, University of Beira Interior, Av. Infante D. Henrique, 6200-506 Covilhã, Portugal
| | - Francisco Gama
- CICS-UBI-Health Sciences Research Centre, University of Beira Interior, Av. Infante D. Henrique, 6200-506 Covilhã, Portugal
- Faculty of Health Sciences, University of Beira Interior, Av. Infante D. Henrique, 6200-506 Covilhã, Portugal
| | - Maria F Gomes
- CICS-UBI-Health Sciences Research Centre, University of Beira Interior, Av. Infante D. Henrique, 6200-506 Covilhã, Portugal
- Faculty of Health Sciences, University of Beira Interior, Av. Infante D. Henrique, 6200-506 Covilhã, Portugal
| | - Lina E Rodrigues
- CICS-UBI-Health Sciences Research Centre, University of Beira Interior, Av. Infante D. Henrique, 6200-506 Covilhã, Portugal
- Faculty of Health Sciences, University of Beira Interior, Av. Infante D. Henrique, 6200-506 Covilhã, Portugal
| | - Sara Meirinho
- CICS-UBI-Health Sciences Research Centre, University of Beira Interior, Av. Infante D. Henrique, 6200-506 Covilhã, Portugal
- Faculty of Health Sciences, University of Beira Interior, Av. Infante D. Henrique, 6200-506 Covilhã, Portugal
| | - Samuel Silvestre
- CICS-UBI-Health Sciences Research Centre, University of Beira Interior, Av. Infante D. Henrique, 6200-506 Covilhã, Portugal
- Faculty of Sciences, University of Beira Interior, Rua Marquês d'Ávila e Bolama, 6201-001 Covilhã, Portugal
| | - Gilberto Alves
- CICS-UBI-Health Sciences Research Centre, University of Beira Interior, Av. Infante D. Henrique, 6200-506 Covilhã, Portugal
- Faculty of Health Sciences, University of Beira Interior, Av. Infante D. Henrique, 6200-506 Covilhã, Portugal
| | - Adriana O Santos
- CICS-UBI-Health Sciences Research Centre, University of Beira Interior, Av. Infante D. Henrique, 6200-506 Covilhã, Portugal
- Faculty of Health Sciences, University of Beira Interior, Av. Infante D. Henrique, 6200-506 Covilhã, Portugal
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Karasawa A, Andi B, Fuchs MR, Shi W, McSweeney S, Hendrickson WA, Liu Q. Multi-crystal native-SAD phasing at 5 keV with a helium environment. IUCrJ 2022; 9:768-777. [PMID: 36381147 PMCID: PMC9634608 DOI: 10.1107/s205225252200971x] [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] [Figures] [Subscribe] [Scholar Register] [Received: 08/18/2022] [Accepted: 10/03/2022] [Indexed: 06/16/2023]
Abstract
De novo structure determination from single-wavelength anomalous diffraction using native sulfur or phospho-rus in biomolecules (native-SAD) is an appealing method to mitigate the labor-intensive production of heavy-atom derivatives and seleno-methio-nyl substitutions. The native-SAD method is particularly attractive for membrane proteins, which are difficult to produce and often recalcitrant to grow into decent-sized crystals. Native-SAD uses lower-energy X-rays to enhance anomalous signals from sulfur or phospho-rus. However, at lower energies, the scattering and absorption of air contribute to the background noise, reduce the signals and are thus adverse to native-SAD phasing. We have previously demonstrated native-SAD phasing at an energy of 5 keV in air at the NSLS-II FMX beamline. Here, the use of a helium path developed to reduce both the noise from background scattering and the air absorption of the diffracted X-ray beam are described. The helium path was used for collection of anomalous diffraction data at 5 keV for two proteins: thaumatin and the membrane protein TehA. Although anomalous signals from each individual crystal are very weak, robust anomalous signals are obtained from data assembled from micrometre-sized crystals. The thaumatin structure was determined from 15 microcrystals and the TehA structure from 18 microcrystals. These results demonstrate the usefulness of a helium environment in support of native-SAD phasing at 5 keV.
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Affiliation(s)
- Akira Karasawa
- Center on Membrane Protein Production and Analysis, New York Structural Biology Center, New York, NY 10027, USA
| | - Babak Andi
- Photon Sciences, NSLS-II, Brookhaven National Laboratory, Upton, NY 11973, USA
| | - Martin R. Fuchs
- Photon Sciences, NSLS-II, Brookhaven National Laboratory, Upton, NY 11973, USA
| | - Wuxian Shi
- Photon Sciences, NSLS-II, Brookhaven National Laboratory, Upton, NY 11973, USA
| | - Sean McSweeney
- Photon Sciences, NSLS-II, Brookhaven National Laboratory, Upton, NY 11973, USA
| | - Wayne A. Hendrickson
- Center on Membrane Protein Production and Analysis, New York Structural Biology Center, New York, NY 10027, USA
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY 10032, USA
- Department of Physiology and Cellular Biophysics, Columbia University, New York, NY 10032, USA
| | - Qun Liu
- Photon Sciences, NSLS-II, Brookhaven National Laboratory, Upton, NY 11973, USA
- Biology Department, Brookhaven National Laboratory, Upton, NY 11973, USA
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Defoort-Levkov GRN, Bahm A, Philipp P. Influence of water contamination on the sputtering of silicon with low-energy argon ions investigated by molecular dynamics simulations. Beilstein J Nanotechnol 2022; 13:986-1003. [PMID: 36225852 PMCID: PMC9520830 DOI: 10.3762/bjnano.13.86] [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] [Figures] [Subscribe] [Scholar Register] [Received: 03/17/2022] [Accepted: 09/06/2022] [Indexed: 06/16/2023]
Abstract
Focused ion beams (FIB) are a common tool in nanotechnology for surface analysis, sample preparation for electron microscopy and atom probe tomography, surface patterning, nanolithography, nanomachining, and nanoprinting. For many of these applications, a precise control of ion-beam-induced processes is essential. The effect of contaminations on these processes has not been thoroughly explored but can often be substantial, especially for ultralow impact energies in the sub-keV range. In this paper we investigate by molecular dynamics (MD) simulations how one of the most commonly found residual contaminations in vacuum chambers (i.e., water adsorbed on a silicon surface) influences sputtering by 100 eV argon ions. The incidence angle was changed from normal incidence to close to grazing incidence. For the simulation conditions used in this work, the adsorption of water favours the formation of defects in silicon by mixing hydrogen and oxygen atoms into the substrate. The sputtering yield of silicon is not significantly changed by the contamination, but the fraction of hydrogen and oxygen atoms that is sputtered largely depends on the incidence angle. This fraction is the largest for incidence angles between 70 and 80° defined with respect to the sample surface. Overall, it changes from 25% to 65%.
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Affiliation(s)
- Grégoire R N Defoort-Levkov
- Advanced Instrumentation for Nano-Analytics (AINA), Materials Research and Technology Department (MRT), Luxembourg Institute of Science and Technology (LIST), 4422 Belvaux, Luxembourg
- University of Luxembourg, 4365 Esch-sur-Alzette, Luxembourg
| | - Alan Bahm
- Thermo Fisher Scientific, Hillsboro, OR, 97124, USA
| | - Patrick Philipp
- Advanced Instrumentation for Nano-Analytics (AINA), Materials Research and Technology Department (MRT), Luxembourg Institute of Science and Technology (LIST), 4422 Belvaux, Luxembourg
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Ogawa T, Yamazawa Y, Kawai S, Mouri A, Katane J, Park IY, Takai Y, Agemura T. A Novel Monochromator with Offset Cylindrical Lenses and Its Application to a Low-Voltage Scanning Electron Microscope. Microsc Microanal 2022; 28:1-13. [PMID: 35164889 DOI: 10.1017/s1431927622000150] [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] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Low-voltage scanning electron microscopes (LV-SEMs) are widely used in nanoscience. However, image resolution for SEMs is restricted by chromatic aberration due to energy spread of the electron beam at low acceleration voltage. This study introduces a new monochromator (MC) with offset cylindrical lenses (CLs) as one solution for LV-SEMs. The MC optics, with highly excited CLs in offset layouts, has advantageous high performance and simple experimental setup, making it suitable for field emission LV-SEMs. In a preliminary evaluation, our MC reduced the energy spread from 770 to 67 meV. The MC was integrated into a commercial SEM equipped with an out-lens (a conventional objective lens without immersion magnetic or retarding electric fields) and an Everhart–Thornley detector. Comparing SEM images under two conditions with the MC turned on or off, the spatial resolution was improved by 58% at 0.5 and 1 keV. The filtering effect of the MC decreased the probe current with a ratio (i.e., transmittance) of 5.7%, which was consistent with estimations based on measured energy spreads. To the best of our knowledge, this is the first report on an effective MC with higher-energy resolution than 100 meV and the results offer encouraging prospects for LV-SEM technology.
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Affiliation(s)
- Takashi Ogawa
- Advanced Instrumentation Institute, Korea Research Institute of Standards and Science, 267 Gajeong-ro, Yuseong, Daejeon34113, Republic of Korea
- Major in Nano Science, University of Science and Technology, 217 Gajeong-ro, Yuseong, Daejeon34113, Republic of Korea
| | - Yu Yamazawa
- Hitachi High-Tech Corporation, 882 Ichige, Hitachinaka, Ibaraki312-8504, Japan
| | - Satoshi Kawai
- Hitachi High-Tech Corporation, 882 Ichige, Hitachinaka, Ibaraki312-8504, Japan
| | - Atsushi Mouri
- Hitachi High-Tech Corporation, 882 Ichige, Hitachinaka, Ibaraki312-8504, Japan
| | - Junichi Katane
- Hitachi High-Tech Corporation, 882 Ichige, Hitachinaka, Ibaraki312-8504, Japan
| | - In-Yong Park
- Advanced Instrumentation Institute, Korea Research Institute of Standards and Science, 267 Gajeong-ro, Yuseong, Daejeon34113, Republic of Korea
- Major in Nano Science, University of Science and Technology, 217 Gajeong-ro, Yuseong, Daejeon34113, Republic of Korea
| | - Yoshizo Takai
- Department of Material and Life Science, Graduate School of Engineering, Osaka University, 2-1 Yamada-oka, Suita, Osaka, Japan
| | - Toshihide Agemura
- Hitachi High-Tech Corporation, 882 Ichige, Hitachinaka, Ibaraki312-8504, Japan
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Bai Y, Buren B, Yang Z, Zhou B, Chen M. Feshbach resonances in D + HD(v = 1, j = 0) reaction at low collision energies. J Comput Chem 2021; 42:2334-2340. [PMID: 34613618 DOI: 10.1002/jcc.26763] [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: 07/16/2021] [Revised: 08/30/2021] [Accepted: 09/20/2021] [Indexed: 11/09/2022]
Abstract
Feshbach resonances in D + HD(v = 1, j = 0) reaction are studied by using the time-independent quantum method. The integral cross section (ICS) results present three Feshbach resonance peaks, which are different from H + HD(v = 1, j = 0) reaction dominated by only one peak. These resonances are attributed to coupling with adiabatic effective potentials of D + HD(v = 1, j = 1) reaction, and the most obvious peak is contributed by J = 1 at 83.16 cm-1 collision energy. For J = 0 and 2, the resonances are related with the same L partial wave and present a double-peak structure in total ICS. The characteristics of product angular distribution show that the resonance of J = 1 is long-lived, while the lifetimes are relatively shorter for the resonance of J = 0 and 2.
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Affiliation(s)
- Yuwen Bai
- Key Laboratory of Materials Modification by Laser, Electron, and Ion Beams (Ministry of Education), School of Physics, Dalian University of Technology, Dalian, China
| | - Bayaer Buren
- Key Laboratory of Materials Modification by Laser, Electron, and Ion Beams (Ministry of Education), School of Physics, Dalian University of Technology, Dalian, China
| | - Zijiang Yang
- Key Laboratory of Materials Modification by Laser, Electron, and Ion Beams (Ministry of Education), School of Physics, Dalian University of Technology, Dalian, China
| | - Boyi Zhou
- Key Laboratory of Materials Modification by Laser, Electron, and Ion Beams (Ministry of Education), School of Physics, Dalian University of Technology, Dalian, China
| | - Maodu Chen
- Key Laboratory of Materials Modification by Laser, Electron, and Ion Beams (Ministry of Education), School of Physics, Dalian University of Technology, Dalian, China
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Rolland M, Truong NP, Parkatzidis K, Pilkington EH, Torzynski AL, Style RW, Dufresne ER, Anastasaki A. Shape-Controlled Nanoparticles from a Low-Energy Nanoemulsion. JACS Au 2021; 1:1975-1986. [PMID: 34841413 PMCID: PMC8611665 DOI: 10.1021/jacsau.1c00321] [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] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/21/2021] [Indexed: 06/13/2023]
Abstract
Nanoemulsion technology enables the production of uniform nanoparticles for a wide range of applications. However, existing nanoemulsion strategies are limited to the production of spherical nanoparticles. Here, we describe a low-energy nanoemulsion method to produce nanoparticles with various morphologies. By selecting a macro-RAFT agent (poly(di(ethylene glycol) ethyl ether methacrylate-co-N-(2-hydroxypropyl) methacrylamide) (P(DEGMA-co-HPMA))) that dramatically lowers the interfacial tension between monomer droplets and water, we can easily produce nanoemulsions at room temperature by manual shaking for a few seconds. With the addition of a common ionic surfactant (SDS), these nanoscale droplets are robustly stabilized at both the formation and elevated temperatures. Upon polymerization, we produce well-defined block copolymers forming nanoparticles with a wide range of controlled morphologies, including spheres, worm balls, worms, and vesicles. Our nanoemulsion polymerization is robust and well-controlled even without stirring or external deoxygenation. This method significantly expands the toolbox and availability of nanoemulsions and their tailor-made polymeric nanomaterials.
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Affiliation(s)
- Manon Rolland
- Laboratory
for Polymeric Materials, Department of Materials, ETH Zürich, Vladimir-Prelog-Weg 5, 8093 Zürich, Switzerland
| | - Nghia P. Truong
- Laboratory
for Polymeric Materials, Department of Materials, ETH Zürich, Vladimir-Prelog-Weg 5, 8093 Zürich, Switzerland
- Monash
Institute of Pharmaceutical Sciences, Monash
University, Parkville, Victoria 3052, Australia
| | - Kostas Parkatzidis
- Laboratory
for Polymeric Materials, Department of Materials, ETH Zürich, Vladimir-Prelog-Weg 5, 8093 Zürich, Switzerland
| | - Emily H. Pilkington
- Monash
Institute of Pharmaceutical Sciences, Monash
University, Parkville, Victoria 3052, Australia
| | - Alexandre L. Torzynski
- Laboratory
of Soft and Living Materials, Department of Materials, ETH Zürich, Vladimir-Prelog-Weg 5, 8093 Zürich, Switzerland
| | - Robert W. Style
- Laboratory
of Soft and Living Materials, Department of Materials, ETH Zürich, Vladimir-Prelog-Weg 5, 8093 Zürich, Switzerland
| | - Eric R. Dufresne
- Laboratory
of Soft and Living Materials, Department of Materials, ETH Zürich, Vladimir-Prelog-Weg 5, 8093 Zürich, Switzerland
| | - Athina Anastasaki
- Laboratory
for Polymeric Materials, Department of Materials, ETH Zürich, Vladimir-Prelog-Weg 5, 8093 Zürich, Switzerland
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Ryterska K, Kordek A, Załęska P. Has Menstruation Disappeared? Functional Hypothalamic Amenorrhea-What Is This Story about? Nutrients 2021; 13:2827. [PMID: 34444987 DOI: 10.3390/nu13082827] [Citation(s) in RCA: 3] [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] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2021] [Revised: 08/10/2021] [Accepted: 08/14/2021] [Indexed: 01/14/2023] Open
Abstract
Functional hypothalamic amenorrhea (FHA) is a very common condition affecting women of procreative age. There are many reasons for this disorder, including a low availability of energy in the diet, low micro- and macronutrient intake, overly intensive physical activity, disturbed regeneration processes, sleep disorders, stress, and psychological disorders. The main determinant is long-term stress and an inability to handle the effects of that stress. FHA is a very complex disorder and often goes undiagnosed. Moreover, therapeutic interventions do not address all the causes of the disorder, which could have implications for women’s health. As shown by scientific reports, this condition can be reversed by modifying its causes. This review of the literature aims to update the current knowledge of functional hypothalamic amenorrhea and underscores the complexity of the disorder, with particular emphasis on the nutritional aspects and potential interventions for restoring balance.
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12
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Calle-García JA, Pedemonte G, Matas M, Albertí G. [Lisfranc lesions: clinical-functional repercussion]. Acta Ortop Mex 2021; 35:311-316. [PMID: 35139588] [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] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
OBJECTIVE Clinical and functional evaluation of patients with Lisfranc lesion without work or sport cause and treated in our center. MATERIAL AND METHODS Thirteen patients with Lisfranc lesion without occupational or sports causes were divided into two groups, high-energy and low-energy injuries. Were analyzed the return to work and sports activity prior to the injury and the use of footwear and insoles after the injury. Also were assessed AOFAS and EVA postoperative score and posterior complications after lesion recovery. RESULTS High-energy group included 7 patients who underwent surgery on an average of 7.3 days. Of the total of patients, 4 presented post-surgical sequelae. Of these patients, one patient was unable to return to their previous work activity and two patients were unable to practice the usual sports activity. The AOFAS was 79.4 and EVA 2.8. In the low energy group, we found six patients operated on 5.6 days on average. All of them were able to return to their previous work and sports activity. The AOFAS were 84.8 and the EVA 1.6. Statistically significant differences were not observed in any of the variables studied. CONCLUSION Patients with Lisfranc injury out of laboral or sports background present good clinical and functional results.
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Affiliation(s)
- J A Calle-García
- Servicio de Cirugía Ortopédica y Traumatología, Hospital Universitari Germans Trias i Pujol, Badalona, Barcelona, España
| | - G Pedemonte
- Servicio de Cirugía Ortopédica y Traumatología, Hospital Universitari Germans Trias i Pujol, Badalona, Barcelona, España
| | - M Matas
- Servicio de Cirugía Ortopédica y Traumatología, Hospital Universitari Germans Trias i Pujol, Badalona, Barcelona, España
| | - G Albertí
- Servicio de Cirugía Ortopédica y Traumatología, Hospital Universitari Germans Trias i Pujol, Badalona, Barcelona, España
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Almuqrin AH, Albarzan B, Olarinoye OI, Kumar A, Alwadai N, Sayyed MI. Mechanical and Gamma Ray Absorption Behavior of PbO-WO 3-Na 2O-MgO-B 2O 3 Glasses in the Low Energy Range. Materials (Basel) 2021; 14:3466. [PMID: 34206454 DOI: 10.3390/ma14133466] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/23/2021] [Revised: 06/02/2021] [Accepted: 06/08/2021] [Indexed: 11/17/2022]
Abstract
The Makishima and Mackenzie model has been used to determine the mechanical properties of the PbO-WO3-Na2O-MgO-B2O3 glass system. The number of bonds per unit volume of the glasses (nb) increases from 9.40 × 1022 to 10.09 × 1022 cm−3 as the PbO content increases from 30 to 50 mol%. The Poisson’s ratio (σ) for the examined glasses falls between 0.174 and 0.210. The value of the fractal bond connectivity (d) for the present glasses ranges from 3.08 to 3.59. Gamma photon and fast neutron shielding parameters were evaluated via Phy-X/PSD, while that of electrons were calculated via the ESTAR platform. Analysis of the parameters showed that both photon and electron attenuation ability improve with the PbO content. The fast neutron removal cross section of the glasses varies from 0.094–0.102 cm−1 as PbO molar content reduced from 50–30 mol%. Further analysis of shielding parameters of the investigated glass system showed that they possess good potential to function in radiation protection applications.
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Rughoobur G, Jain L, Akinwande AI. Electron transmission through suspended graphene membranes measured with a low-voltage gated Si field emitter array. Nanotechnology 2021; 32:285201. [PMID: 33831850 DOI: 10.1088/1361-6528/abf5fb] [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: 12/10/2020] [Accepted: 04/07/2021] [Indexed: 06/12/2023]
Abstract
We experimentally demonstrate the transmission of electrons through different number (1, 2, and 5) of suspended graphene layers at electron energies between 20 and 250 eV. Electrons with initial energies lower than 40 eV are generated using silicon field emitter arrays with 1μm pitch, and accelerated towards the graphene layers supported by a silicon nitride grid biased at voltages from -20 to 200 V. We measured significant increase in current collected at the anode with the presence of graphene, which is attributed to the possible generation of secondary electrons by primary electrons impinging on the graphene membrane. Highest output current was recorded with monolayer graphene at approximately 90 eV, with up to 1.7 times the incident current. The transparency of graphene to low-energy electrons and its impermeability to gas molecules could enable low-voltage field emission electron sources, which often require ultra-high vacuum, to operate in a relatively poor vacuum environment.
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Affiliation(s)
- Girish Rughoobur
- Microsystems Technology Laboratories, Massachusetts Institute of Technology, 60 Vassar Street, Cambridge, MA 02139, United States of America
| | - Lay Jain
- Microsystems Technology Laboratories, Massachusetts Institute of Technology, 60 Vassar Street, Cambridge, MA 02139, United States of America
| | - Akintunde I Akinwande
- Microsystems Technology Laboratories, Massachusetts Institute of Technology, 60 Vassar Street, Cambridge, MA 02139, United States of America
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Latz C, Asshauer T, Rathjen C, Mirshahi A. Femtosecond-Laser Assisted Surgery of the Eye: Overview and Impact of the Low-Energy Concept. Micromachines (Basel) 2021; 12:122. [PMID: 33498878 DOI: 10.3390/mi12020122] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/15/2020] [Revised: 01/13/2021] [Accepted: 01/18/2021] [Indexed: 11/16/2022]
Abstract
This article provides an overview of both established and innovative applications of femtosecond (fs)-laser-assisted surgical techniques in ophthalmology. Fs-laser technology is unique because it allows cutting tissue at very high precision inside the eye. Fs lasers are mainly used for surgery of the human cornea and lens. New areas of application in ophthalmology are on the horizon. The latest improvement is the high pulse frequency, low-energy concept; by enlarging the numerical aperture of the focusing optics, the pulse energy threshold for optical breakdown decreases, and cutting with practically no side effects is enabled.
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Gledovic A, Janosevic Lezaic A, Nikolic I, Tasic-Kostov M, Antic-Stankovic J, Krstonosic V, Randjelovic D, Bozic D, Ilic D, Tamburic S, Savic S. Polyglycerol Ester-Based Low Energy Nanoemulsions with Red Raspberry Seed Oil and Fruit Extracts: Formulation Development toward Effective In Vitro/In Vivo Bioperformance. Nanomaterials (Basel) 2021; 11:nano11010217. [PMID: 33467701 PMCID: PMC7830947 DOI: 10.3390/nano11010217] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [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: 12/13/2020] [Revised: 01/11/2021] [Accepted: 01/12/2021] [Indexed: 01/15/2023]
Abstract
This study focuses on the development of biocompatible oil-in-water (O/W) nanoemulsions based on polyglycerol esters, as promising carriers for natural actives: red raspberry seed oil—RO and hydro-glycolic fruit extracts from red raspberry—RE and French oak—FE. Nanoemulsions were obtained via phase inversion composition (PIC) method at room temperature by dilution of microemulsion phase, confirmed by visual appearance, percentage of transmittance, microscopic, rheological and differential scanning calorimetry (DSC) investigations. The results have shown that the basic RO-loaded formulation could be further enriched with hydro-glycolic fruit extracts from red raspberry or French oak, while keeping a semi-transparent appearance due to the fine droplet size (Z-ave: 50 to 70 nm, PDI value ≤ 0.1). The highest antioxidant activity (~92% inhibition of the DPPH radical) was achieved in the formulation containing both lipophilic (RO) and hydrophilic antioxidants (FE), due to their synergistic effect. The nanoemulsion carrier significantly increased the selective cytotoxic effect of RO towards malignant melanoma (Fem-X) cells, compared to normal human keratinocytes (HaCaT). In vivo study on human volunteers showed satisfactory safety profiles and significant improvement in skin hydration during 2 h after application for all nanoemulsions. Therefore, polyglycerol ester-based nanoemulsions can be promoted as effective carriers for red raspberry seed oil and/or hydro-glycolic fruit extracts in topical formulations intended for skin protection and hydration.
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Affiliation(s)
- Ana Gledovic
- Department of Pharmaceutical Technology and Cosmetology, Faculty of Pharmacy, University of Belgrade, 11121 Belgrade, Serbia;
- Correspondence: (A.G.); (S.S.); Tel.: +381-113951367 (A.G.); +381-113951288 (S.S.)
| | - Aleksandra Janosevic Lezaic
- Department of Physical Chemistry and Instrumental Methods, Faculty of Pharmacy, University of Belgrade, 11121 Belgrade, Serbia;
| | - Ines Nikolic
- Department of Pharmaceutical Technology and Cosmetology, Faculty of Pharmacy, University of Belgrade, 11121 Belgrade, Serbia;
| | - Marija Tasic-Kostov
- Department of Pharmacy, Faculty of Medicine, University of Nis, 18000 Nis, Serbia; (M.T.-K.); (D.I.)
| | - Jelena Antic-Stankovic
- Department of Microbiology and Immunology, Faculty of Pharmacy, University of Belgrade, 11121 Belgrade, Serbia; (J.A.-S.); (D.B.)
| | - Veljko Krstonosic
- Department of Pharmacy, Faculty of Medicine, University of Novi Sad, 21000 Novi Sad, Serbia;
| | - Danijela Randjelovic
- Department of Microelectronic Technologies, Institute of Chemistry, Technology and Metallurgy, University of Belgrade, 11000 Belgrade, Serbia;
| | - Dragana Bozic
- Department of Microbiology and Immunology, Faculty of Pharmacy, University of Belgrade, 11121 Belgrade, Serbia; (J.A.-S.); (D.B.)
| | - Dusan Ilic
- Department of Pharmacy, Faculty of Medicine, University of Nis, 18000 Nis, Serbia; (M.T.-K.); (D.I.)
| | - Slobodanka Tamburic
- Cosmetic Science Research Group, London College of Fashion, University of the Arts London, London WC1V 7EY, UK;
| | - Snezana Savic
- Department of Pharmaceutical Technology and Cosmetology, Faculty of Pharmacy, University of Belgrade, 11121 Belgrade, Serbia;
- Correspondence: (A.G.); (S.S.); Tel.: +381-113951367 (A.G.); +381-113951288 (S.S.)
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Michalczyk MM, Maszczyk A, Stastny P. The Effects of Low-Energy Moderate-Carbohydrate (MCD) and Mixed (MixD) Diets on Serum Lipid Profiles and Body Composition in Middle-Aged Men: A Randomized Controlled Parallel-Group Clinical Trial. Int J Environ Res Public Health 2020; 17:E1332. [PMID: 32092918 DOI: 10.3390/ijerph17041332] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/05/2020] [Revised: 02/14/2020] [Accepted: 02/18/2020] [Indexed: 12/17/2022]
Abstract
Carbohydrate-restricted diets have become very popular due to their numerous health benefits. The aim of this study was to determine the influence of 4 weeks of a well-planned, low-energy moderate-carbohydrate diet (MCD) and a low-energy mixed diet (MixD) on the lipoprotein profile, glucose and C-reactive protein concentrations, body mass, and body composition in middle-aged males. Sixty middle-aged males were randomly assigned to the following groups: hypocaloric MCD (32% carbohydrates, 28% proteins, and 40% fat), hypocaloric MixD (50% carbohydrates, 20% proteins, and 30% fat), and a conventional (control) diet (CD; 48% carbohydrates, 15% proteins, and 37% fat). The participants who were classified into the MCD and MixD groups consumed 20% fewer calories daily than the total daily energy expenditure (TDEE). Baseline and postintervention fasting triacylglycerol (TG), LDL (low-density lipoprotein) cholesterol (LDL-C), HDL (high-density lipoprotein) cholesterol (HDL-C), total cholesterol (tCh), glucose (Gl), and C-reactive protein were evaluated. Body mass (BM) and body composition changes, including body fat (BF), % body fat (PBF), and muscle mass (MM), were monitored. Compared with MixD and CD, MCD significantly changed the fasting serum concentrations of TG (p < 0.05), HDL-C (p < 0.05), LDL-C (p < 0.05), tCh (p < 0.05), and glucose (p < 0.01). Additionally, body fat content (kg and %) was significantly reduced (p < 0.05) after MCD compared with MixD and CD. After the MixD intervention, BM and MM decreased (p < 0.05) compared with baseline values. Compared with baseline, after the MixD, BM, MM, tCh, LDL-C, and TG changed significantly. The 4 week low-energy MCD intervention changed lipoproteins, glucose, and body fat to a greater extent than the low-energy MixD. A hypocaloric MCD may be suggested for middle-aged male subjects who want to lose weight by reducing body fat content without compromising muscle mass.
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Xu L, Yu RJ, Ding XM, Li M, Wu Y, Zhu L, Chen D, Peng C, Zeng CJ, Guo WY. Efficacy of low-energy selective laser trabeculoplasty on the treatment of primary open angle glaucoma. Int J Ophthalmol 2019; 12:1432-1437. [PMID: 31544039 DOI: 10.18240/ijo.2019.09.10] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [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: 12/18/2018] [Accepted: 04/08/2019] [Indexed: 12/20/2022] Open
Abstract
AIM To investigate the efficacy of low-energy selective laser trabeculoplasty (SLT) on the treatment of primary open angle glaucoma (POAG) patients. METHODS Outpatients with POAG who underwent 360-degree SLT using an initial energy of 0.3 mJ (total energy of 30-40 mJ) were reviewed retrospectively from September 2011 to January 2018. RESULTS Eight-six eyes of 44 POAG patients underwent 360-degree SLT using initial energy of 0.3 mJ and were followed up regularly. The total energy used was 32.5±2.5 mJ (23-40 mJ, 105±6 spots). The average pretreatment intraocular pressure (IOP) was 19.8±3.9 mm Hg. At 1, 3, 6mo, 1, and 2y, the post-SLT IOPs (mm Hg) were 16.9±3.3, 16.5±3.3, 17.1±3.4, 16.6±3.5, 16.5±2.8, which were significantly lower than that before treatment (P<0.001). The patients in the SLT success group were found to be younger than those in the SLT failure group. After SLT, 59 eyes that maintained pretreatment medications were defined as the drug retention group. The pre-SLT IOP was 20.1±3.7 mm Hg. At 1, 3, 6mo, 1, and 2y, the post-SLT IOPs (mm Hg) were 17.3±3.6, 16.6±3.5, 17.2±3.6, 16.9±3.8 and 16.5±2.9, respectively. Twenty-seven eyes that required reduced drugs were defined as the drug reduction group. The pre-SLT IOP was 19.2±4.4 mm Hg. At 1, 3, 6mo, 1, and 2y, the post-SLT IOPs (mm Hg) were 16.1±2.6, 16.5±3.1, 16.8±2.9, 16.0±2.6 and 16.3±2.4, respectively. Compared with the pretreatment IOPs, the post-SLT IOPs were significantly lower in drug retention group and drug reduction group. The patients in the drug reduction group were found to be younger than those in the drug retention group. CONCLUSION Low-energy SLT is safe and effective for POAG patients during a 2-year follow-up. Younger POAG patients may obtain better results after low-energy SLT treatment.
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Affiliation(s)
- Li Xu
- Department of Ophthalmology, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200011, China.,Shanghai Key Laboratory of Orbital Diseases and Ocular Oncology, Shanghai 200011, China
| | - Ru-Jing Yu
- Department of Ophthalmology, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200011, China.,Shanghai Key Laboratory of Orbital Diseases and Ocular Oncology, Shanghai 200011, China
| | - Xu-Ming Ding
- Department of Ophthalmology, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200011, China.,Shanghai Key Laboratory of Orbital Diseases and Ocular Oncology, Shanghai 200011, China
| | - Mao Li
- Department of Ophthalmology, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200011, China.,Shanghai Key Laboratory of Orbital Diseases and Ocular Oncology, Shanghai 200011, China
| | - Yue Wu
- Department of Ophthalmology, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200011, China.,Shanghai Key Laboratory of Orbital Diseases and Ocular Oncology, Shanghai 200011, China
| | - Li Zhu
- Department of Ophthalmology, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200011, China.,Shanghai Key Laboratory of Orbital Diseases and Ocular Oncology, Shanghai 200011, China
| | - Di Chen
- Department of Ophthalmology, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200011, China.,Shanghai Key Laboratory of Orbital Diseases and Ocular Oncology, Shanghai 200011, China
| | - Cheng Peng
- Department of Ophthalmology, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200011, China.,Shanghai Key Laboratory of Orbital Diseases and Ocular Oncology, Shanghai 200011, China
| | - Chang-Juan Zeng
- Department of Ophthalmology, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200011, China.,Shanghai Key Laboratory of Orbital Diseases and Ocular Oncology, Shanghai 200011, China
| | - Wen-Yi Guo
- Department of Ophthalmology, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200011, China.,Shanghai Key Laboratory of Orbital Diseases and Ocular Oncology, Shanghai 200011, China
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Sun DZ, Sun L, Yang Y. On Secure Simple Pairing in Bluetooth Standard v5.0-Part II: Privacy Analysis and Enhancement for Low Energy. Sensors (Basel) 2019; 19:E3259. [PMID: 31344911 DOI: 10.3390/s19153259] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/12/2019] [Revised: 07/16/2019] [Accepted: 07/17/2019] [Indexed: 11/16/2022]
Abstract
Bluetooth low energy devices are very popular in wireless personal area networks. According to the Bluetooth standard specifications, the low energy secure simple pairing (LESSP) protocol is the process by which the pairing devices negotiate the authenticated secret key. To violate the user privacy, the adversary can perhaps link the runs of the LESSP protocol to the targeted device, which usually relates to the specially appointed user. Hence, we investigate deep into the privacy of the LESSP protocol. Our main contributions are threefold: (1) We demonstrate that the LESSP protocol suffers from privacy vulnerability. That is, an adversary without any secret key is able to identify the targeted device by the LESSP protocol. (2) An improvement is therefore proposed to repair the privacy vulnerability in the LESSP protocol. (3) We develop a formal privacy model to evaluate the privacy vulnerabilities in the LESSP protocol and its improved versions. We further prove that our improvement on the LESSP protocol is private under the privacy model. In addition, the performance evaluation shows that our improvement is as efficient as the LESSP protocol. Our research results are beneficial to the privacy enhancement of Bluetooth systems in wireless personal area networks.
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Bird JT, Tague ED, Zinke L, Schmidt JM, Steen AD, Reese B, Marshall IPG, Webster G, Weightman A, Castro HF, Campagna SR, Lloyd KG. Uncultured Microbial Phyla Suggest Mechanisms for Multi-Thousand-Year Subsistence in Baltic Sea Sediments. mBio 2019; 10:e02376-18. [PMID: 30992358 DOI: 10.1128/mBio.02376-18] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Much of life on Earth exists in a very slow-growing state, with microbes from deeply buried marine sediments representing an extreme example. These environments are like natural laboratories that have run multi-thousand-year experiments that are impossible to perform in a laboratory. We borrowed some techniques that are commonly used in laboratory experiments and applied them to these natural samples to make hypotheses about how these microbes subsist for so long at low activity. We found that some methods for stabilizing proteins and nucleic acids might be used by many members of the community. We also found evidence for niche differentiation strategies, and possibly cross-feeding, suggesting that even though they are barely growing, complex ecological interactions continue to occur over ultralong timescales. Energy-starved microbes in deep marine sediments subsist at near-zero growth for thousands of years, yet the mechanisms for their subsistence are unknown because no model strains have been cultivated from most of these groups. We investigated Baltic Sea sediments with single-cell genomics, metabolomics, metatranscriptomics, and enzyme assays to identify possible subsistence mechanisms employed by uncultured Atribacteria, Aminicenantes, Actinobacteria group OPB41, Aerophobetes, Chloroflexi, Deltaproteobacteria, Desulfatiglans, Bathyarchaeota, and Euryarchaeota marine group II lineages. Some functions appeared to be shared by multiple lineages, such as trehalose production and NAD+-consuming deacetylation, both of which have been shown to increase cellular life spans in other organisms by stabilizing proteins and nucleic acids, respectively. Other possible subsistence mechanisms differed between lineages, possibly providing them different physiological niches. Enzyme assays and transcripts suggested that Atribacteria and Actinobacteria group OPB41 catabolized sugars, whereas Aminicenantes and Atribacteria catabolized peptides. Metabolite and transcript data suggested that Atribacteria utilized allantoin, possibly as an energetic substrate or chemical protectant, and also possessed energy-efficient sodium pumps. Atribacteria single-cell amplified genomes (SAGs) recruited transcripts for full pathways for the production of all 20 canonical amino acids, and the gene for amino acid exporter YddG was one of their most highly transcribed genes, suggesting that they may benefit from metabolic interdependence with other cells. Subsistence of uncultured phyla in deep subsurface sediments may occur through shared strategies of using chemical protectants for biomolecular stabilization, but also by differentiating into physiological niches and metabolic interdependencies.
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Wijesooriya K. Part I: Out-of-field dose mapping for 6X and 6X-flattening-filter-free beams on the TrueBeam for extended distances. Med Phys 2019; 46:868-876. [PMID: 30589941 DOI: 10.1002/mp.13362] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [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: 01/09/2018] [Revised: 12/03/2018] [Accepted: 12/17/2018] [Indexed: 01/09/2023] Open
Abstract
PURPOSE With increasing cancer treatment success rates, many patients go on to live long, productive lives following recovery. Therefore, minimizing potential side effects due to dose outside the treated field is becoming a significant consideration in radiation therapy. With many potential treatment configurations available, it is important to quantify how out-of-field dose varies with common variables such as distance from isocenter, couch angle, jaw size, and flattening-filter setting. The accurate quantification of out-of-field dose at extended distances could also benefit researchers and detector developers. While data exist for out-of-field dose from older linear accelerator (Linac) models, the phenomenon has not been described for the latest generation of machines, such as the Varian TrueBeam. The purpose of this study was to comprehensively quantify out-of-field dose for the Varian TrueBeam Linac low energy photons in a wide range of positions and treatment geometries. METHOD AND MATERIALS Out-of-field doses were measured using two phantom setups: (a) A large volume ion chamber with a buildup sleeve to quantify head leakage and collimator scatter background dose; and (b) A farmer ion chamber in solid water to incorporate phantom scatter in addition to collimator scatter, and head leakage background dose. In both cases, the ion chamber was positioned with its length along the slowly varying transverse direction (perpendicular to the radial from isocenter). Doses were measured for four symmetric jaw settings (2 × 2 cm2 , 4 × 4 cm2 , 10 × 10 cm2 , and 20 × 20 cm2 ) for a range of distances from the isocenter (0-100 cm). The angular dependence of the out-of-field dose was measured using four different angles: 0°, 45°, 90°, and 135° with respect to the in-plane direction. All measurements were performed for both 6X and 6X-flattening-filter-free (FFF) beams. RESULTS The lowest out-of-field doses were observed at 60 cm away from isocenter in both in-plane and cross-plane directions for fields smaller than 10 × 10 cm2 . Out-of-field dose decreased with decreasing jaw size (a factor of 4.7 for 6X-FFF and a factor of 3.1 for 6X going from 20 × 20 cm2 to 2 × 2 cm2 at 60 cm from isocenter in the in-plane direction). The 6X-FFF beam produced out-of-field doses as low as 64% of the 6X beam. CONCLUSION This study presents a comprehensive description of 6X and 6X-FFF out-of-field doses on a Varian TrueBeam Linac including measurements at a range of positions, angles, and jaw settings and with and without phantom scatter.
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Affiliation(s)
- Krishni Wijesooriya
- Department of Radiation Oncology, University of Virginia, Charlottesville, VA, 22908, USA.,Department of Physics, University of Virginia, Charlottesville, VA, 22904, USA
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Wang J, Shen J, Shi W, Qiao G, Wu S, Wang X. A Novel Energy-Efficient Contention-Based MAC Protocol Used for OA-UWSN. Sensors (Basel) 2019; 19:E183. [PMID: 30621019 DOI: 10.3390/s19010183] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/28/2018] [Revised: 12/26/2018] [Accepted: 12/26/2018] [Indexed: 11/16/2022]
Abstract
A hybrid optical-acoustic underwater wireless sensor network (OA-UWSN) was proposed to solve the problem of high-speed transmission of real-time video and images in marine information detection. This paper proposes a novel energy-efficient contention-based media access control (MAC) protocol (OA-CMAC) for the OA-UWSN. Based on optical-acoustic fusion technology, our proposed OA-CMAC combines the postponed access mechanism in carrier sense multiple access with collision avoidance (CSMA/CA) and multiplexing-based spatial division multiple access (SDMA) technology to achieve high-speed and real-time data transmission. The protocol first performs an acoustic handshake to obtain the location information of a transceiver node, ensuring that the channel is idle. Otherwise, it performs postponed access and waits for the next time slot to contend for the channel again. Then, an optical handshake is performed to detect whether the channel condition satisfies the optical transmission, and beam alignment is performed at the same time. Finally, the nodes transmit data using optical communication. If the channel conditions do not meet the requirements for optical communication, a small amount of data with high priority is transmitted through acoustic communication. An evaluation of the proposed MAC protocol was performed with OMNeT++ simulations. The results showed that when the optical handshaking success ratio was greater than 50%, compared to the O-A handshake protocol in the literature, our protocol could result in doubled throughput. Due to the low energy consumption of optical communication, the node's lifetime is 30% longer than that of pure acoustic communication, greatly reducing the network operation cost. Therefore, it is suitable for large-scale underwater sensor networks with high loads.
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Bradley JA, Amend JP, LaRowe DE. Survival of the fewest: Microbial dormancy and maintenance in marine sediments through deep time. Geobiology 2019; 17:43-59. [PMID: 30248245 PMCID: PMC6585783 DOI: 10.1111/gbi.12313] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/05/2018] [Revised: 07/17/2018] [Accepted: 08/21/2018] [Indexed: 06/01/2023]
Abstract
Microorganisms buried in marine sediments are known to endure starvation over geologic timescales. However, the mechanisms of how these microorganisms cope with prolonged energy limitation is unknown and therefore yet to be captured in a quantitative framework. Here, we present a novel mathematical model that considers (a) the physiological transitions between the active and dormant states of microorganisms, (b) the varying requirement for maintenance power between these phases, and (c) flexibility in the provenance (i.e., source) of energy from exogenous and endogenous catabolism. The model is applied to sediments underlying the oligotrophic South Pacific Gyre where microorganisms endure ultra-low fluxes of energy for tens of millions of years. Good fits between model simulations and measurements of cellular carbon and organic carbon concentrations are obtained and are interpreted as follows: (a) the unfavourable microbial habitat in South Pacific Gyre sediments triggers rapid mortality and a transition to dormancy; (b) there is minimal biomass growth, and organic carbon consumption is dominated by catabolism to support maintenance activities rather than new biomass synthesis; (c) the amount of organic carbon that microorganisms consume for maintenance activities is equivalent to approximately 2% of their carbon biomass per year; and (d) microorganisms must rely solely on exogenous rather than endogenous catabolism to persist in South Pacific Gyre sediments over long timescales. This leads us to the conclusion that under oligotrophic conditions, the fitness of an organism is determined by its ability to simply stay alive, rather than to grow. This modelling framework is designed to be flexible for application to other sites and habitats, and thus serves as a new quantitative tool for determining the habitability of and an ultimate limit for life in any environment.
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Affiliation(s)
- James A. Bradley
- Department of Earth SciencesUniversity of Southern CaliforniaLos AngelesCalifornia
| | - Jan P. Amend
- Department of Earth SciencesUniversity of Southern CaliforniaLos AngelesCalifornia
- Department of Biological SciencesUniversity of Southern CaliforniaLos AngelesCalifornia
| | - Douglas E. LaRowe
- Department of Earth SciencesUniversity of Southern CaliforniaLos AngelesCalifornia
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Omura Y. Empirical and Theoretical Modeling of Low-Frequency Noise Behavior of Ultrathin Silicon-on-Insulator MOSFETs Aiming at Low-Voltage and Low-Energy Regime. Micromachines (Basel) 2018; 10:E5. [PMID: 30583561 DOI: 10.3390/mi10010005] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/04/2018] [Revised: 12/15/2018] [Accepted: 12/18/2018] [Indexed: 11/16/2022]
Abstract
This paper theoretically revisits the low-frequency noise behavior of the inversion-channel silicon-on-insulator metal-oxide-semiconductor field-effect transistor (SOI MOSFET) and the buried-channel SOI MOSFET because the quality of both Si/SiO2 interfaces (top and bottom) should modulate the low-frequency fluctuation characteristics of both devices. It also addresses the low-frequency noise behavior of sub-100-nm channel SOI MOSFETs. We deepen the discussion of the low-frequency noise behavior in the subthreshold bias range in order to elucidate the device’s potential for future low-voltage and low-power applications. As expected, analyses suggest that the weak inversion channel near the top surface of the SOI MOSFET is strongly influenced by interface traps near the top surface of the SOI layer because the traps are not well shielded by low-density surface inversion carriers in the subthreshold bias range. Unexpectedly, we find that the buried channel is primarily influenced by interface traps near the top surface of the SOI layer, not by traps near the bottom surface of the SOI layer. This is not due to the simplified capacitance coupling effect. These interesting characteristics of current fluctuation spectral intensity are explained well by the theoretical models proposed here.
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Abstract
Earth's subsurface is often isolated from phototrophic energy sources and characterized by chemotrophic modes of life. These environments are often oligotrophic and limited in electron donors or electron acceptors, and include continental crust, subseafloor oceanic crust, and marine sediment as well as subglacial lakes and the subsurface of polar desert soils. These low energy subsurface environments are therefore uniquely positioned for examining minimum energetic requirements and adaptations for chemotrophic life. Current targets for astrobiology investigations of extant life are planetary bodies with largely inhospitable surfaces, such as Mars, Europa, and Enceladus. Subsurface environments on Earth thus serve as analogs to explore possibilities of subsurface life on extraterrestrial bodies. The purpose of this review is to provide an overview of subsurface environments as potential analogs, and the features of microbial communities existing in these low energy environments, with particular emphasis on how they inform the study of energetic limits required for life. The thermodynamic energetic calculations presented here suggest that free energy yields of reactions and energy density of some metabolic redox reactions on Mars, Europa, Enceladus, and Titan could be comparable to analog environments in Earth's low energy subsurface habitats.
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Affiliation(s)
| | | | - Beth N. Orcutt
- Bigelow Laboratory for Ocean Sciences, East Boothbay, ME, United States
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Bartmann W, Belochitskii P, Breuker H, Butin F, Carli C, Eriksson T, Oelert W, Ostojic R, Pasinelli S, Tranquille G. The ELENA facility. Philos Trans A Math Phys Eng Sci 2018; 376:rsta.2017.0266. [PMID: 29459416 PMCID: PMC5829171 DOI: 10.1098/rsta.2017.0266] [Citation(s) in RCA: 5] [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] [Accepted: 01/08/2018] [Indexed: 06/08/2023]
Abstract
The CERN Antiproton Decelerator (AD) provides antiproton beams with a kinetic energy of 5.3 MeV to an active user community. The experiments would profit from a lower beam energy, but this extraction energy is the lowest one possible under good conditions with the given circumference of the AD. The Extra Low Energy Antiproton ring (ELENA) is a small synchrotron with a circumference a factor of 6 smaller than the AD to further decelerate antiprotons from the AD from 5.3 MeV to 100 keV. Controlled deceleration in a synchrotron equipped with an electron cooler to reduce emittances in all three planes will allow the existing AD experiments to increase substantially their antiproton capture efficiencies and render new experiments possible. ELENA ring commissioning is taking place at present and first beams to a new experiment installed in a new experimental area are foreseen in 2017. The transfer lines from ELENA to existing experiments in the old experimental area will be installed during CERN Long Shutdown 2 (LS2) in 2019 and 2020. The status of the project and ring commissioning will be reported.This article is part of the Theo Murphy meeting issue 'Antiproton physics in the ELENA era'.
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Affiliation(s)
| | | | | | | | | | | | - Walter Oelert
- Johannes Gutenberg University Mainz, 55099 Mainz, Germany
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Derbez M, Wyart G, Le Ponner E, Ramalho O, Ribéron J, Mandin C. Indoor air quality in energy-efficient dwellings: Levels and sources of pollutants. Indoor Air 2018; 28:318-338. [PMID: 28960493 DOI: 10.1111/ina.12431] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [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: 01/23/2017] [Accepted: 09/21/2017] [Indexed: 05/12/2023]
Abstract
Worldwide, public policies are promoting energy-efficient buildings and accelerating the thermal renovation of existing buildings. The effects of these changes on the indoor air quality (IAQ) in these buildings remain insufficiently understood. In this context, a field study was conducted in 72 energy-efficient dwellings to describe the pollutants known to be associated with health concerns. Measured parameters included the concentrations of 19 volatile organic compounds and aldehydes, nitrogen dioxide, particulate matter (PM2.5 ), radon, temperature, and relative humidity. The air stuffiness index and night-time air exchange rate were calculated from the monitored carbon dioxide (CO2 ) concentrations. Indoor and outdoor measurements were performed at each dwelling during 1 week in each of the two following seasons: heating and non-heating. Moreover, questionnaires were completed by the occupants to characterize the building, equipment, household, and occupants' habits. Perspective on our results was provided by previous measurements made in low-energy European dwellings. Statistical comparisons with the French housing stock and a pilot study showed higher concentrations of terpenes, that is, alpha-pinene and limonene, and hexaldehyde in our study than in previous studies. Alpha-pinene and hexaldehyde are emitted by wood or wood-based products used for the construction, insulation, decoration, and furnishings of the dwellings, whereas limonene is more associated with discontinuous sources related to human activities.
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Affiliation(s)
- M Derbez
- Scientific and Technical Center for Building (CSTB), Health and Comfort Direction, French Observatory of Indoor Air Quality (OQAI), University of Paris-Est, Marne la Vallée Cedex 2, France
| | - G Wyart
- Scientific and Technical Center for Building (CSTB), Health and Comfort Direction, French Observatory of Indoor Air Quality (OQAI), University of Paris-Est, Marne la Vallée Cedex 2, France
| | - E Le Ponner
- Scientific and Technical Center for Building (CSTB), Health and Comfort Direction, French Observatory of Indoor Air Quality (OQAI), University of Paris-Est, Marne la Vallée Cedex 2, France
| | - O Ramalho
- Scientific and Technical Center for Building (CSTB), Health and Comfort Direction, French Observatory of Indoor Air Quality (OQAI), University of Paris-Est, Marne la Vallée Cedex 2, France
| | - J Ribéron
- Scientific and Technical Center for Building (CSTB), Health and Comfort Direction, French Observatory of Indoor Air Quality (OQAI), University of Paris-Est, Marne la Vallée Cedex 2, France
| | - C Mandin
- Scientific and Technical Center for Building (CSTB), Health and Comfort Direction, French Observatory of Indoor Air Quality (OQAI), University of Paris-Est, Marne la Vallée Cedex 2, France
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Abstract
Marine sediments constitute one of the most energy-limited habitats on Earth, in which microorganisms persist over extraordinarily long timescales with very slow metabolisms. This habitat provides an ideal environment in which to study the energetic limits of life. However, the bioenergetic factors that can determine whether microorganisms will grow, lie dormant, or die, as well as the selective environmental pressures that determine energetic trade-offs between growth and maintenance activities, are not well understood. Numerical models will be pivotal in addressing these knowledge gaps. However, models rarely account for the variable physiological states of microorganisms and their demand for energy. Here, we review established modeling constructs for microbial growth rate, yield, maintenance, and physiological state, and then provide a new model that incorporates all of these factors. We discuss this new model in context with its future application to the marine subsurface. Understanding the factors that regulate cell death, physiological state changes, and the provenance of maintenance energy (i.e., endogenous versus exogenous metabolism), is crucial to the design of this model. Further, measurements of growth rate, growth yield, and basal metabolic activity will enable bioenergetic parameters to be better constrained. Last, biomass and biogeochemical rate measurements will enable model simulations to be validated. The insight provided from the development and application of new microbial modeling tools for marine sediments will undoubtedly advance the understanding of the minimum power required to support life, and the ecophysiological strategies that organisms utilize to cope under extreme energy limitation for extended periods of time.
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Affiliation(s)
- James A Bradley
- Department of Earth Sciences, University of Southern California, Los Angeles, CA, United States
| | - Jan P Amend
- Department of Earth Sciences, University of Southern California, Los Angeles, CA, United States.,Department of Biological Sciences, University of Southern California, Los Angeles, CA, United States
| | - Douglas E LaRowe
- Department of Earth Sciences, University of Southern California, Los Angeles, CA, United States
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Abstract
BACKGROUND Lisfranc injuries result from high- and low-energy mechanisms though the literature has been more focused on high-energy mechanisms. A comparison of high-energy (HE) and low-energy (LE) injury patterns is lacking. The objective of this study was to report injury patterns in LE Lisfranc joint injuries and compare them to HE injury patterns. METHODS Operative Lisfranc injuries were identified over a 5-year period. Patient demographics, mechanism of injury, injury pattern, associated injuries, missed diagnoses, clinical course, and imaging studies were reviewed and compared. HE mechanism was defined as motor vehicle crash, motorcycle crash, direct crush, and fall from greater than 4 feet and LE mechanism as athletic activity, ground level twisting, or fall from less than 4 feet. Thirty-two HE and 48 LE cases were identified with 19.3 months of average follow-up. RESULTS There were no differences in demographics or missed diagnosis frequency (21% HE vs 18% LE). Time to seek care was not significantly different. HE injuries were more likely to have concomitant nonfoot fractures (37% vs 6%), concomitant foot fractures (78% vs 4%), cuboid fractures (31% vs 6%), metatarsal base fractures (84% vs 29%), displaced intra-articular fractures (59% vs 4%), and involvement of all 5 rays (23% vs 6%). LE injuries were more commonly ligamentous (68% vs 16%), with fewer rays involved (2.7 vs 4.1). CONCLUSIONS LE mechanisms were a more common cause of Lisfranc joint injury in this cohort. These mechanisms generally resulted in an isolated, primarily ligamentous injury sparing the lateral column. Both types had high rates of missed injury that could result in delayed treatment. Differences in injury patterns could help direct future research to optimize treatment algorithms. LEVEL OF EVIDENCE Level III, comparative series.
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Affiliation(s)
- Christopher H Renninger
- 1 Trauma and Foot and Ankle Surgery, Department of Orthopedics, Naval Medical Center San Diego, San Diego, CA, USA
| | - Grant Cochran
- 1 Trauma and Foot and Ankle Surgery, Department of Orthopedics, Naval Medical Center San Diego, San Diego, CA, USA
| | - Trevor Tompane
- 1 Trauma and Foot and Ankle Surgery, Department of Orthopedics, Naval Medical Center San Diego, San Diego, CA, USA
| | - Joseph Bellamy
- 1 Trauma and Foot and Ankle Surgery, Department of Orthopedics, Naval Medical Center San Diego, San Diego, CA, USA
| | - Kevin Kuhn
- 1 Trauma and Foot and Ankle Surgery, Department of Orthopedics, Naval Medical Center San Diego, San Diego, CA, USA
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Yamashita M, Leyden MR, Adaniya H, Cheung MP, Hirai T, Qi Y, Shintake T. Graphene specimen support technique for low voltage STEM imaging. Microscopy (Oxf) 2017; 66:261-271. [PMID: 28453814 DOI: 10.1093/jmicro/dfx014] [Citation(s) in RCA: 2] [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: 11/09/2016] [Accepted: 04/13/2017] [Indexed: 06/07/2023] Open
Abstract
The scanning transmission electron microscopy (STEM) mode of today's field emission scanning electron microscopes enables sub-nanometer resolution imaging. Graphene is a single-atom thick, electrically conductive material, making it an excellent specimen support for the low voltage STEM imaging of nanometer-sized objects such as viruses. Here we present low voltage STEM images of bacteriophage T4 recorded on highly cleaned graphene films. The results show that ultrathin graphene support films markedly improve image signal at low accelerating voltages. Staining with a low atomic number methylamine vanadate stain combined with the graphene support film enables the clear visualization of the fine structure of the T4 tail by the low voltage STEM technique. Despite the advantages of graphene support films, difficulties are often encountered in placing hydrophilic biological samples on hydrophobic graphene electron microscopy grids. We employed a spin sedimentation sample loading method to overcome this problem.
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Affiliation(s)
- Masao Yamashita
- Okinawa Institute of Science and Technology Graduate University, 1919-1 Tancha, Onna-son, Kunigami-gun, Okinawa 904-0495, Japan
| | - Matthew Ryan Leyden
- Okinawa Institute of Science and Technology Graduate University, 1919-1 Tancha, Onna-son, Kunigami-gun, Okinawa 904-0495, Japan
| | - Hidehito Adaniya
- Okinawa Institute of Science and Technology Graduate University, 1919-1 Tancha, Onna-son, Kunigami-gun, Okinawa 904-0495, Japan
| | - Martin Philip Cheung
- Okinawa Institute of Science and Technology Graduate University, 1919-1 Tancha, Onna-son, Kunigami-gun, Okinawa 904-0495, Japan
| | - Teruhisa Hirai
- Cellular and Structural Physiology Institute, Nagoya University, Chikusa-ku, Furo-cho, Nagoya 464-8601, Japan
| | - Yabing Qi
- Okinawa Institute of Science and Technology Graduate University, 1919-1 Tancha, Onna-son, Kunigami-gun, Okinawa 904-0495, Japan
| | - Tsumoru Shintake
- Okinawa Institute of Science and Technology Graduate University, 1919-1 Tancha, Onna-son, Kunigami-gun, Okinawa 904-0495, Japan
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Connolly AJ, Vigmond E, Bishop MJ. Bidomain Predictions of Virtual Electrode-Induced Make and Break Excitations around Blood Vessels. Front Bioeng Biotechnol 2017; 5:18. [PMID: 28396856 PMCID: PMC5366349 DOI: 10.3389/fbioe.2017.00018] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [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: 12/12/2016] [Accepted: 03/02/2017] [Indexed: 11/16/2022] Open
Abstract
Introduction and background Virtual electrodes formed by field stimulation during defibrillation of cardiac tissue play an important role in eliciting activations. It has been suggested that the coronary vasculature is an important source of virtual electrodes, especially during low-energy defibrillation. This work aims to further the understanding of how virtual electrodes from the coronary vasculature influence defibrillation outcomes. Methods Using the bidomain model, we investigated how field stimulation elicited activations from virtual electrodes around idealized intramural blood vessels. Strength–interval curves, which quantify the stimulus strength required to elicit wavefront propagation from the vessels at different states of tissue refractoriness, were computed for each idealized geometry. Results Make excitations occurred at late diastolic intervals, originating from regions of depolarization around the vessel. Break excitations occurred at early diastolic intervals, whereby the vessels were able to excite surrounding refractory tissue due to the local restoration of excitability by virtual electrode-induced hyperpolarizations. Overall, strength–interval curves had similar morphologies and underlying excitation mechanisms compared with previous experimental and numerical unipolar stimulation studies of cardiac tissue. Including the presence of the vessel wall increased the field strength required for make excitations but decreased the field strength required for break excitations, and the field strength at which break excitations occurred was generally greater than 5 V/cm. Finally, in a more realistic ventricular slice geometry, the proximity of virtual electrodes around subepicardial vessels was seen to cause break excitations in the form of propagating unstable wavelets to the subepicardial layer. Conclusion Representing the blood vessel wall microstructure in computational bidomain models of defibrillation is recommended as it significantly alters the electrophysiological response of the vessel to field stimulation. Although vessels may facilitate excitation of relatively refractory tissue via break excitations, the field strength required for this is generally greater than those used in the literature on low-energy defibrillation. However, the high-intensity shocks used in standard defibrillation may elicit break excitation propagation from the coronary vasculature.
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Affiliation(s)
- Adam J Connolly
- Department of Biomedical Engineering and Imaging Sciences, King's College London , London , UK
| | - Edward Vigmond
- IHU Liryc, Electrophysiology and Heart Modeling Instituté, Fondation Bordeaux Université, Bordeaux, France; IMB, UMR 5251, Univ. Bordeaux, Talence, France
| | - Martin J Bishop
- Department of Biomedical Engineering and Imaging Sciences, King's College London , London , UK
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Forde P, Kennelly C, Gerrity S, Collins G, Clifford E. An evaluation of the performance and optimization of a new wastewater treatment technology: the air suction flow-biofilm reactor. Environ Technol 2015; 36:1188-1204. [PMID: 25413003 DOI: 10.1080/09593330.2014.982724] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
In this laboratory study, a novel wastewater treatment technology, the air suction flow-biofilm reactor (ASF-BR) - a sequencing batch biofilm reactor technology with a passive aeration mechanism - was investigated for its efficiency in removing organic carbon, nitrogen and phosphorus, from high-strength synthetic wastewaters. A laboratory-scale ASF-BR comprising 2 reactors, 350 mm in diameter and 450 mm in height, was investigated over 2 studies (Studies 1 and 2) for a total of 430 days. Study 1 lasted a total of 166 days and involved a 9-step sequence alternating between aeration, anoxic treatment and settlement. The cycle time was 12.1 h and the reactors were operated at a substrate loading rate of 3.60 g filtered chemical oxygen demand (CODf)/m2 media/d, 0.28 g filtered total nitrogen (TNf)/m2 media/d, 0.24 g ammonium-nitrogen (NH4-N)/m2 media/d and 0.07 g ortho-phosphate (PO4-P)/m2 media/d. The average removal rates achieved during Study 1 were 98% CODf, 88% TNf, 97% NH4-N and 35% PO4-P. During Study 2 (264 days), the unit was operated at a loading rate of 2.49 g CODf/m2 media/d, 0.24 g TNf/m2 media/d, 0.20 g NH4-N/m2 media/d and 0.06 PO4-P/m2 media/d. The energy requirement during this study was reduced by modifying the treatment cycle in include fewer pumping cycles. Removal rates in Study 2 averaged 97% CODf, 86% TNf, 99% NH4-N and 76% PO4-P. The excess sludge production of the system was evaluated and detailed analyses of the treatment cycles were carried out. Biomass yields were estimated at 0.09 g SS/g CODf, removed and 0.21 g SS/g CODf, removed for Studies 1 and 2, respectively. Gene analysis showed that the use of a partial vacuum did not affect the growth of ammonia-oxidizing bacteria. The results indicate that the ASF-BR and passive aeration technologies can offer efficient alternatives to existing technologies.
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Affiliation(s)
- P Forde
- a Civil Engineering, College of Engineering and Informatics , National University of Ireland, Galway , Galway , Ireland
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Abstract
We have developed a gamma-ray imaging system that combines a high-resolution silicon detector with two sets of movable, half-keel-edged copper-tungsten blades configured as crossed slits. These apertures can be positioned independently between the object and detector, producing an anamorphic image in which the axial and transaxial magnifications are not constrained to be equal. The detector is a 60 mm × 60 mm, one-millimeter-thick, one-megapixel silicon double-sided strip detector with a strip pitch of 59 μm. The flexible nature of this system allows the application of adaptive imaging techniques. We present system details; calibration, acquisition, and reconstruction methods; and imaging results.
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Janardhan AH, Gutbrod SR, Li W, Lang D, Schuessler RB, Efimov IR. Multistage electrotherapy delivered through chronically-implanted leads terminates atrial fibrillation with lower energy than a single biphasic shock. J Am Coll Cardiol 2013; 63:40-8. [PMID: 24076284 DOI: 10.1016/j.jacc.2013.07.098] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/22/2013] [Revised: 07/24/2013] [Accepted: 07/27/2013] [Indexed: 10/26/2022]
Abstract
OBJECTIVES The goal of this study was to develop a low-energy, implantable device-based multistage electrotherapy (MSE) to terminate atrial fibrillation (AF). BACKGROUND Previous attempts to perform cardioversion of AF by using an implantable device were limited by the pain caused by use of a high-energy single biphasic shock (BPS). METHODS Transvenous leads were implanted into the right atrium (RA), coronary sinus, and left pulmonary artery of 14 dogs. Self-sustaining AF was induced by 6 ± 2 weeks of high-rate RA pacing. Atrial defibrillation thresholds of standard versus experimental electrotherapies were measured in vivo and studied by using optical imaging in vitro. RESULTS The mean AF cycle length (CL) in vivo was 112 ± 21 ms (534 beats/min). The impedances of the RA-left pulmonary artery and RA-coronary sinus shock vectors were similar (121 ± 11 Ω vs. 126 ± 9 Ω; p = 0.27). BPS required 1.48 ± 0.91 J (165 ± 34 V) to terminate AF. In contrast, MSE terminated AF with significantly less energy (0.16 ± 0.16 J; p < 0.001) and significantly lower peak voltage (31.1 ± 19.3 V; p < 0.001). In vitro optical imaging studies found that AF was maintained by localized foci originating from pulmonary vein-left atrium interfaces. MSE Stage 1 shocks temporarily disrupted localized foci; MSE Stage 2 entrainment shocks continued to silence the localized foci driving AF; and MSE Stage 3 pacing stimuli enabled consistent RA-left atrium activation until sinus rhythm was restored. CONCLUSIONS Low-energy MSE significantly reduced the atrial defibrillation thresholds compared with BPS in a canine model of AF. MSE may enable painless, device-based AF therapy.
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Affiliation(s)
- Ajit H Janardhan
- Department of Medicine, Cardiovascular Division, Washington University School of Medicine, St. Louis, Missouri
| | - Sarah R Gutbrod
- Department of Biomedical Engineering, Washington University, St. Louis, Missouri
| | - Wenwen Li
- Department of Biomedical Engineering, Washington University, St. Louis, Missouri
| | - Di Lang
- Department of Biomedical Engineering, Washington University, St. Louis, Missouri
| | - Richard B Schuessler
- Department of Biomedical Engineering, Washington University, St. Louis, Missouri; Department of Surgery, Cardiothoracic Division, Washington University School of Medicine, St. Louis, Missouri
| | - Igor R Efimov
- Department of Medicine, Cardiovascular Division, Washington University School of Medicine, St. Louis, Missouri; Department of Biomedical Engineering, Washington University, St. Louis, Missouri.
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Kano S, Tanikawa H, Mogami Y, Shibata SI, Takanashi S, Oji Y, Aoki T, Oba H, Ikegami S, Takahashi J. Comparison between continuous and discontinuous multiple vertebral compression fractures. Eur Spine J 2012; 21:1867-72. [PMID: 22391866 PMCID: PMC3459131 DOI: 10.1007/s00586-012-2210-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [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: 06/05/2011] [Revised: 11/07/2011] [Accepted: 02/17/2012] [Indexed: 10/28/2022]
Abstract
BACKGROUND The majority of multiple vertebral fractures (MVFs) occur under high-energy conditions; however, some cases occurring under minor-energy conditions exist. Fractures in successive vertebrae (continuous type) and in skipped vertebrae (discontinuous type) can exist. PURPOSE The objective of this study was to compare and evaluate the cause, level of injury, and relationship to osteoporosis between continuous and discontinuous MVFs. METHODS We studied 77 subjects (173 vertebrae) who had presented with acute back pain between September 2007 and April 2010 and who received diagnoses of fresh MVFs through magnetic resonance imaging. Subjects with continuous and discontinuous fractures were evaluated based on age, sex, bone mineral density (BMD), level of affected vertebrae, and cause of injury. RESULTS Subjects with discontinuous MVFs were significantly older and comprised more female patients. Mean BMD, measured by dual-emission X-ray absorptiometry, was 0.70 and 0.58 g/cm(3) for the continuous and discontinuous MVFs, respectively, demonstrating a significant difference. Of 34 patients with discontinuous MVFs, 32 (94%) exhibited vertebral fractures in the thoracolumbar junction. In subjects with continuous MVFs, the MVFs of 19 (44%) subjects were caused by high-energy trauma, whereas mild trauma and unknown cause were identified in 14 (41%) and 13 (38%) subjects with discontinuous MVFs, respectively. CONCLUSIONS Discontinuous MVFs generally caused by mild outer force, and often occurred at the thoracolumbar junction. Continuous MVFs, frequently, were caused by high-energy trauma.
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Affiliation(s)
- Shuji Kano
- Department of Orthopaedic Surgery, Azumi General Hospital, 3207-1 Ikeda, Ikeda-machi, Kita-azumi-gun, Nagano, 399-8695, Japan,
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Lenart BA, Neviaser AS, Lyman S, Chang CC, Edobor-Osula F, Steele B, van der Meulen MCH, Lorich DG, Lane JM. Association of low-energy femoral fractures with prolonged bisphosphonate use: a case control study. Osteoporos Int 2009; 20:1353-62. [PMID: 19066707 PMCID: PMC4415520 DOI: 10.1007/s00198-008-0805-x] [Citation(s) in RCA: 253] [Impact Index Per Article: 16.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/28/2008] [Accepted: 10/01/2008] [Indexed: 10/21/2022]
Abstract
SUMMARY Recent evidence has linked long-term bisphosphonate use with insufficiency fractures of the femur in postmenopausal women. In this case-control study, we have identified a significant association between a unique fracture of the femoral shaft, a transverse fracture in an area of thickened cortices, and long-term bisphosphonate use. Further studies are warranted. INTRODUCTION Although clinical trials confirm the anti-fracture efficacy of bisphosphonates over 3-5 years, the long-term effects of bisphosphonate use on bone metabolism are unknown. Femoral insufficiency fractures in patients on prolonged treatment have been reported. METHODS We performed a retrospective case-control study of postmenopausal women who presented with low-energy femoral fractures from 2000 to 2007. Forty-one subtrochanteric and femoral shaft fracture cases were identified and matched by age, race, and body mass index to one intertrochanteric and femoral neck fracture each. RESULTS Bisphosphonate use was observed in 15 of the 41 subtrochanteric/shaft cases, compared to nine of the 82 intertrochanteric/femoral neck controls (Mantel-Haenszel odds ratio (OR), 4.44 [95% confidence interval (CI) 1.77-11.35]; P = 0.002). A common X-ray pattern was identified in ten of the 15 subtrochanteric/shaft cases on a bisphosphonate. This X-ray pattern was highly associated with bisphosphonate use (OR, 15.33 [95% CI 3.06-76.90]; P < 0.001). Duration of bisphosphonate use was longer in subtrochanteric/shaft cases compared to both hip fracture controls groups (P = 0.001). CONCLUSIONS We found a significantly greater proportion of patients with subtrochanteric/shaft fractures to be on long-term bisphosphonates than intertrochanteric/femoral neck fractures. Bisphosphonate use was highly associated with a unique X-ray pattern. Further studies are warranted.
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Affiliation(s)
- B. A. Lenart
- Hospital for Special Surgery, 535 E. 70th St., New York, NY 10021, USA. Weill Medical College, Cornell University, New York, NY, USA
| | - A. S. Neviaser
- Hospital for Special Surgery, 535 E. 70th St., New York, NY 10021, USA. Medical Orthopedic Trauma Service, New York Presbyterian Hospital–Weill Cornell Medical Center, New York, NY, USA
| | - S. Lyman
- Methodology & Statistics Core, Hospital for Special Surgery, 535 E. 70th St., New York, NY 10021, USA
| | - C. C. Chang
- Hospital for Special Surgery, 535 E. 70th St., New York, NY 10021, USA. Weill Medical College, Cornell University, New York, NY, USA
| | - F. Edobor-Osula
- Hospital for Special Surgery, 535 E. 70th St., New York, NY 10021, USA. Weill Medical College, Cornell University, New York, NY, USA
| | - B. Steele
- Hospital for Special Surgery, 535 E. 70th St., New York, NY 10021, USA. Weill Medical College, Cornell University, New York, NY, USA
| | - M. C. H. van der Meulen
- Mechanical & Aerospace Engineering, Cornell University, 219A Upson Hall, Ithaca, NY 14853, USA
| | - D. G. Lorich
- Hospital for Special Surgery, 535 E. 70th St., New York, NY 10021, USA. Weill Medical College, Cornell University, New York, NY, USA. Medical Orthopedic Trauma Service, New York Presbyterian Hospital–Weill Cornell Medical Center, New York, NY, USA
| | - J. M. Lane
- Hospital for Special Surgery, 535 E. 70th St., New York, NY 10021, USA. Weill Medical College, Cornell University, New York, NY, USA. Medical Orthopedic Trauma Service, New York Presbyterian Hospital–Weill Cornell Medical Center, New York, NY, USA
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Wang Y, Yoon SF, Ngo CY, Ahn J. Surface Morphology Evolution of GaAs by Low Energy Ion Sputtering. Nanoscale Res Lett 2007; 2:504. [PMCID: PMC3246606 DOI: 10.1007/s11671-007-9090-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/18/2007] [Accepted: 08/17/2007] [Indexed: 05/31/2023]
Abstract
Low energy Ar+ion sputtering, typically below 1,200 eV, of GaAs at normal beam incident angle is investigated. Surface morphology development with respect to varying energy is analyzed and discussed. Dot-like patterns in the nanometer scale are obtained above 600 eV. As the energy approaches upper eV range regular dots have evolved. The energy dependent dot evolution is evaluated based on solutions of the isotropic Kuramoto-Sivashinsky equation. The results are in agreement with the theoretical model which describes a power law dependency of the characteristic wavelength on ion energy in the ion-induced diffusion regime.
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Affiliation(s)
- Y Wang
- School of Electrical and Electronic Engineering, Nanyang Technological University, Nanyang Avenue, Singapore, 639798, Singapore
| | - SF Yoon
- School of Electrical and Electronic Engineering, Nanyang Technological University, Nanyang Avenue, Singapore, 639798, Singapore
| | - CY Ngo
- School of Electrical and Electronic Engineering, Nanyang Technological University, Nanyang Avenue, Singapore, 639798, Singapore
| | - J Ahn
- School of Electrical and Electronic Engineering, Nanyang Technological University, Nanyang Avenue, Singapore, 639798, Singapore
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