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Integrated molybdenum single atom array sensors with multichannels for nitrite detection in foods. Biosens Bioelectron 2024; 257:116345. [PMID: 38692247 DOI: 10.1016/j.bios.2024.116345] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2024] [Revised: 04/15/2024] [Accepted: 04/26/2024] [Indexed: 05/03/2024]
Abstract
Nitrite (NO2-) is present in a variety of foods, but the excessive intake of NO2- can indirectly lead to carcinogenic, teratogenic, mutagenicity and other risks to the human body. Therefore, the detection of NO2- is crucial for maintaining human health. In this study, an integrated array sensor for NO2- detection is developed based on molybdenum single atom material (IMSMo-SAC) using high-resolution electrohydrodynamic (EHD) printing technology. The sensor comprises three components: a printed electrode array, multichannels designed on polydimethylsiloxane (PDMS) and an electronic signal process device with bluetooth. By utilizing Mo-SAC to facilitate electron transfer during the redox reaction, rapid and efficient detection of NO2- can be achieved. The sensor has a wide linear range of 0.1 μM-107.8 mM, a low detection limit of 33 nM and a high sensitivity of 0.637 mA-1mM-1 cm-2. Furthermore, employing this portable array sensor allows simultaneously measurements of NO2- concentrations in six different foods samples with acceptable recovery rates. This array sensor holds great potential for detecting of small molecules in various fields.
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Machine Learning-Assistant Colorimetric Sensor Arrays for Intelligent and Rapid Diagnosis of Urinary Tract Infection. ACS Sens 2024. [PMID: 38530950 DOI: 10.1021/acssensors.3c02687] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/28/2024]
Abstract
Urinary tract infections (UTIs), which can lead to pyelonephritis, urosepsis, and even death, are among the most prevalent infectious diseases worldwide, with a notable increase in treatment costs due to the emergence of drug-resistant pathogens. Current diagnostic strategies for UTIs, such as urine culture and flow cytometry, require time-consuming protocols and expensive equipment. We present here a machine learning-assisted colorimetric sensor array based on recognition of ligand-functionalized Fe single-atom nanozymes (SANs) for the identification of microorganisms at the order, genus, and species levels. Colorimetric sensor arrays are built from the SAN Fe1-NC functionalized with four types of recognition ligands, generating unique microbial identification fingerprints. By integrating the colorimetric sensor arrays with a trained computational classification model, the platform can identify more than 10 microorganisms in UTI urine samples within 1 h. Diagnostic accuracy of up to 97% was achieved in 60 UTI clinical samples, holding great potential for translation into clinical practice applications.
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Nickel Single-Atom Catalyst Boosts Electrochemiluminescence of Graphitic Carbon Nitride for Sensitive Detection of HBV DNA. Anal Chem 2023; 95:18207-18214. [PMID: 38010370 DOI: 10.1021/acs.analchem.3c03989] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2023]
Abstract
Owing to excellent catalytic activity, single-atom catalysts (SACs) have recently attracted considerable research interest in the electrochemiluminescence (ECL) field. However, the applications of SACs are mostly limited to conventional luminol ECL system. Hence, it is necessary to explore the application of SACs in more ECL systems. In this work, nickel single-atom catalysts (Ni SACs) were successfully applied in the graphitic carbon nitride (g-C3N4)-H2O2 ECL system to significantly enhance its cathodic emission. Notably, g-C3N4 acted not only as an ECL luminophore but also as a support to anchor Ni SACs. Ni SACs can significantly activate H2O2 to produce abundant OH• radicals for enhancing the cathodic ECL emission of g-C3N4. Ni SACs-anchored g-C3N4 (Ni SACs@g-C3N4) had a 10-fold enhanced ECL intensity as compared to g-C3N4. Finally, the Ni SACs@g-C3N4-H2O2 ECL system was developed to detect hepatitis B virus (HBV) DNA by incorporating an entropy-driven DNA walking machine-assisted CRISPR-Cas12a amplification strategy. The constructed biosensor exhibited excellent detection performance for HBV DNA with a limit of detection as low as 17 aM. This work puts forward a new idea for enhancing the cathodic ECL of g-C3N4-H2O2 and expands the application of SACs in the ECL system.
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[Short-term observation of electrical acoustic stimulation in patients with low frequency residual hearing after cochlear implant]. ZHONGHUA ER BI YAN HOU TOU JING WAI KE ZA ZHI = CHINESE JOURNAL OF OTORHINOLARYNGOLOGY HEAD AND NECK SURGERY 2023; 58:1173-1182. [PMID: 38186091 DOI: 10.3760/cma.j.cn115330-20230907-00081] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Indexed: 01/09/2024]
Abstract
Objective: To analyze the effects of electrical acoustic stimulation (EAS) on speech and tone recognition as well as music perception in children with low-frequency residual hearing (LFRH) after cochlear implant (CI). Methods: A total of twelve Mandarin patients with LFRH who underwent unilateral CI from January 2017 to October 2020 were recruited, including 8 males and 4 females. There were 5 cases of pre-lingual deafness and 7 cases of post-lingual deafness. The median age at implantation was 12 years old (3-62 years). All patients had residual hearing (RH) before surgery, wore hearing aid (HA) timely, had an effective rehabilitation and the duration of use of electrical stimulation was 37.0±16.2 months. On the implanted side, the thresholds of 125 Hz and 250 Hz were less than and equal to 80 dB HL after implantation. A two-month follow-up clinical study was conducted with the EAS devices. The EAS effects were evaluated before, immediately after and 2 months after upgrade, including speech recognition rate, tone recognition and music tests. SPSS 23.0 software was used for statistical analysis. Results: A total of ten patients completed a two-month clinical follow-up and efficiency evaluation. Compared to the electrical stimulation, the recognition rate of spondee word significantly decreased after the immediate use of EAS (71.7±4.3 vs 79.6±3.1, P=0.018). Compared to the electrical stimulation as well as immediate use of EAS, the results of sentence in noise, tone in noise, and SRT of sentence in noise were all significantly improved at 2 months after use of EAS (P<0.05). The pitch discrimination was significantly improved at 2 months after the use of EAS compared with that before the use of EAS (P=0.042). Compared with before (P=0.021) and immediately (P=0.017) use of EAS, the ability of rhythm resolution was significantly improved. There were no significant differences in other test results (P>0.05). Conclusions: The low-frequency acoustic information provided by EAS as well as the electrical-acoustic stimulation mode can provide rich auditory cues of speech perception in noise, tone recognition in noise, and musical discrimination for CI subjects. It can promote the improvement of complex listening ability of CI patients undergoing long-term electrical stimulation in a short time and comprehensively improve their hearing capacities.
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A single-atom cobalt integrated flexible sensor for simultaneous detection of dihydroxybenzene isomers. NANOSCALE 2023. [PMID: 37161875 DOI: 10.1039/d2nr06293c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
Simultaneous detection of dihydroxybenzene isomers including hydroquinone (HQ), catechol (CC), and resorcinol (RS) is significant for water quality control as they are highly toxic and often coexist. However, it is a great challenge to realize their accurate and simultaneous detection due to their similarity in structure and properties. Herein, an electrochemical flexible strip with single-atom cobalt (SA-Co/NG) was constructed through high-resolution electrohydrodynamic (EHD) printing for dihydroxybenzene isomer's simultaneous detection. Results showed that the provided SA-Co/NG strip exhibited excellent sensing performance with reliable repeatability, reproducibility, long-term stability, and flexibility. Linear ranges of 0.50-31 745 μM, 0.50-5909 μM, and 0.50-153.5 μM were achieved for HQ, CC, and RS, respectively, with a detection limit of 0.164 μM. Based on the experimental data, the mechanism concerning SA-Co/NG catalytic activity towards HQ can be deduced, starting from the combination of Co* and OH- in water, followed by the formation of Co-OH-dihydroxybenzene, and finally leading to O-H bond dissociation to generate benzoquinone. As for CC or RS, pyridinic N or CO synergistic with a single Co atom catalyzes their oxidation. Besides, the printed flexible SA-Co/NG strip further demonstrates the accurate and simultaneous detection of HQ, CC, and RS in textile wastewater, proposing a powerful practical application.
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Integrated Biochip-Electronic System with Single-Atom Nanozyme for in Vivo Analysis of Nitric Oxide. ACS NANO 2023; 17:8575-8585. [PMID: 37084243 DOI: 10.1021/acsnano.3c00935] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
Nitric oxide (NO) exhibits a crucial role in various versatile and distinct physiological functions. Hence, its real-time sensing is highly important. Herein, we developed an integrated nanoelectronic system comprising a cobalt single-atom nanozyme (Co-SAE) chip array sensor and an electronic signal processing module (INDCo-SAE) for both in vitro and in vivo multichannel qualifying of NO in normal and tumor-bearing mice. The high atomic utilization and catalytic activity of Co-SAE endowed an ultrawide linear range for NO varying from 36 to 4.1 × 105 nM with a low detection limit of 12 nM. Combining in situ attenuated total reflectance surface enhanced infrared spectroscopy (ATR-SEIRAS) measurements and density function calculation revealed the activating mechanism of Co-SAE toward NO. The NO adsorption on an active Co atom forms *NO, followed by the reaction between *NO and OH-, which could help design relevant nanozymes. Further, we investigated the NO-producing behaviors of various organs of both normal and tumor-bearing mice using the proposed device. We also evaluated the NO yield produced by the wounded mouse using the designed device and found it to be approximately 15 times that of the normal mouse. This study bridges the technical gap between a biosensor and an integrated system for molecular analysis in vitro and in vivo. The as-fabricated integrated wireless nanoelectronic system with multiple test channels significantly improved the detection efficiency, which can be widely used in designing other portable sensing devices with multiplexed analysis capability.
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Unique BiFeO 3/g-C 3N 4 mushroom heterojunction with photocatalytic antibacterial and wound therapeutic activity. NANOSCALE 2022; 14:2686-2695. [PMID: 35107477 DOI: 10.1039/d1nr08016d] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Bacterial infections have become a major problem threatening public health, and it is of great significance to treat wound infections in biological systems caused by bacteria. However, traditionally used bacteriostatic agents usually cause additional pollution. Herein a mushroom-shaped clean and Green BiFeO3/g-C3N4 composite is employed for the first time for photocatalytic antibacterial activity and for the further promotion of wound healing. The ratio between BiFeO3 and g-C3N4 was delicately regulated to control the generated amount of ˙OH and ˙O2- by catalyzing the decomposition of hydrogen peroxide (H2O2) under illumination. Results show that 10%BFO/CN demonstrates the best performance for ˙OH and ˙O2- production, resulting in the highest antibacterial ability against E. coli and S. aureus. In addition, the catalytic mechanism of BiFeO3/g-C3N4 towards antibacterial activity is disclosed by a combination of ESR monitoring and analysis of the Mott-Schottky diagram. Furthermore, in vivo experiments prove that 10%BFO/CN can effectively promote anti-infection and wound healing in nude mice. This work sheds deep scientific insight on the synergistic effect of photocatalysis and photo-Fenton degradation as well as their application in antibacterial and wound therapeutic activity.
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Boron-Nitrogen-Co-Doping Nanocarbons to Create Rich Electroactive Defects toward Simultaneous Sensing Hydroquinone and Catechol. Electrochim Acta 2022. [DOI: 10.1016/j.electacta.2021.139427] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
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Recent advances in single atom catalysts for the electrochemical carbon dioxide reduction reaction. Chem Sci 2021; 12:6800-6819. [PMID: 34123313 PMCID: PMC8153444 DOI: 10.1039/d1sc01375k] [Citation(s) in RCA: 42] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2021] [Accepted: 04/07/2021] [Indexed: 12/02/2022] Open
Abstract
The electrochemical carbon dioxide reduction reaction (CO2RR) offers a promising solution to mitigate carbon emission and at the same time generate valuable carbonaceous chemicals/fuels. Single atom catalysts (SACs) are encouraging to catalyze the electrochemical CO2RR due to the tunable electronic structure of the central metal atoms, which can regulate the adsorption energy of reactants and reaction intermediates. Moreover, SACs form a bridge between homogeneous and heterogeneous catalysts, providing an ideal platform to explore the reaction mechanism of electrochemical reactions. In this review, we first discuss the strategies for promoting the CO2RR performance, including suppression of the hydrogen evolution reaction (HER), generation of C1 products and formation of C2+ products. Then, we summarize the recent developments in regulating the structure of SACs toward the CO2RR based on the above aspects. Finally, several issues regarding the development of SACs for the CO2RR are raised and possible solutions are provided.
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Single-Atom Ruthenium Biomimetic Enzyme for Simultaneous Electrochemical Detection of Dopamine and Uric Acid. Anal Chem 2021; 93:4916-4923. [PMID: 33719390 DOI: 10.1021/acs.analchem.0c05191] [Citation(s) in RCA: 60] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Single-atom catalysts have attracted numerous attention due to the high utilization of metallic atoms, abundant active sites, and highly catalytic activities. Herein, a single-atom ruthenium biomimetic enzyme (Ru-Ala-C3N4) is prepared by dispersing Ru atoms on a carbon nitride support for the simultaneous electrochemical detection of dopamine (DA) and uric acid (UA), which are coexisting important biological molecules involving in many physiological and pathological aspects. The morphology and elemental states of the single-atom Ru catalyst are studied by transmission electron microscopy, energy dispersive X-ray elemental mapping, high-angle annular dark field-scanning transmission electron microscopy, and high-resolution X-ray photoelectron spectroscopy. Results show that Ru atoms atomically disperse throughout the C3N4 support by Ru-N chemical bonds. The electrochemical characterizations indicate that the Ru-Ala-C3N4 biosensor can simultaneously detect the oxidation of DA and UA with a separation of peak potential of 180 mV with high sensitivity and excellent selectivity. The calibration curves for DA and UA range from 0.06 to 490 and 0.5 to 2135 μM with detection limits of 20 and 170 nM, respectively. Moreover, the biosensor was applied to detect DA and UA in real biological serum samples using the standard addition method with satisfactory results.
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Single-Atom Cobalt-Based Electrochemical Biomimetic Uric Acid Sensor with Wide Linear Range and Ultralow Detection Limit. NANO-MICRO LETTERS 2020; 13:7. [PMID: 34138193 PMCID: PMC8187548 DOI: 10.1007/s40820-020-00536-9] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/11/2020] [Accepted: 09/13/2020] [Indexed: 05/17/2023]
Abstract
Uric acid (UA) detection is essential in diagnosis of arthritis, preeclampsia, renal disorder, and cardiovascular diseases, but it is very challenging to realize the required wide detection range and low detection limit. We present here a single-atom catalyst consisting of Co(II) atoms coordinated by an average of 3.4 N atoms on an N-doped graphene matrix (A-Co-NG) to build an electrochemical biomimetic sensor for UA detection. The A-Co-NG sensor achieves a wide detection range over 0.4-41,950 μM and an extremely low detection limit of 33.3 ± 0.024 nM, which are much better than previously reported sensors based on various nanostructured materials. Besides, the A-Co-NG sensor also demonstrates its accurate serum diagnosis for UA for its practical application. Combination of experimental and theoretical calculation discovers that the catalytic process of the A-Co-NG toward UA starts from the oxidation of Co species to form a Co3+-OH-UA*, followed by the generation of Co3+-OH + *UA_H, eventually leading to N-H bond dissociation for the formation of oxidized UA molecule and reduction of oxidized Co3+ to Co2+ for the regenerated A-Co-NG. This work provides a promising material to realize UA detection with wide detection range and low detection limit to meet the practical diagnosis requirements, and the proposed sensing mechanism sheds light on fundamental insights for guiding exploration of other biosensing processes.
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[Application of tracheotomy combined with thyrocricocentesis and puncture of front tracheal wall in emergency treatment of laryngeal edema in burn patients]. ZHONGHUA SHAO SHANG ZA ZHI = ZHONGHUA SHAOSHANG ZAZHI = CHINESE JOURNAL OF BURNS 2019; 35:811-813. [PMID: 31775470 DOI: 10.3760/cma.j.issn.1009-2587.2019.11.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Objective: To explore the effect of tracheotomy combined with thyrocricocentesis and puncture of front tracheal wall in emergency treatment of laryngeal edema in patients with burns. Methods: From November 2000 to August 2018, 22 patients with severe burn or extremely severe burn combined with acute laryngeal edema were rescued in the author's unit, including 18 males and 4 females, aged 17 to 68 years. All patients were complicated with mild inhalation injury or above and more than deep partial-thickness burn to head, face, and neck. From November 2000 to October 2012, simple emergency tracheotomy was performed for 12 cases. From May 2013 to August 2018, tracheotomy combined with thyrocricocentesis and puncture of front tracheal wall was performed for 10 cases. Rescue effect and complication of the two kinds of tracheotomy were recorded. Data were processed with Fisher's exact probability test. Results: Among the 12 patients treated with simple emergency tracheotomy, 5 cases survived and 7 cases died of suffocation during tracheotomy. Among the 10 patients treated with tracheotomy combined with thyrocricocentesis and puncture of front tracheal wall, 9 cases survived and 1 case died of cardiac arrest caused by arrhythmia. There was statistically significant difference in successful rescue effect between the two kinds of tracheotomy (P<0.05). Among the 14 patients who were successfully rescued, symptoms of insomnia and post-traumatic stress disorder occurred in 12 cases, which were relieved after symptomatic treatment for 14 to 45 d without permanent hypoxic brain damage. Conclusions: In case of loss of the condition of preventive tracheotomy, first aid of acute laryngeal edema of burn patient is very difficult. Tracheotomy combined with thyrocricocentesis and puncture of front tracheal wall is simple and rapid with high successful rate and amelioration of hypoxia, which is an ideal plan for laryngeal edema.
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Enhanced electrochemiluminescence from reduced graphene oxide-CdTe quantum dots for highly selective determination of copper ion. LUMINESCENCE 2019; 34:666-672. [PMID: 31243864 DOI: 10.1002/bio.3649] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2019] [Revised: 04/17/2019] [Accepted: 05/05/2019] [Indexed: 12/11/2022]
Abstract
An electrochemiluminescence (ECL) sensor based on reduced graphene oxide-CdTe quantum dots (RGO-CdTe QDs) composites for detecting copper ion (Cu2+ ) was proposed. The ECL behaviours of the RGO-CdTe QD modified electrode were investigated with H2 O2 as the co-reactant. Quantitative detection of Cu2+ was realized as Cu2+ could effectively quench the ECL signal of the RGO-CdTe QDs. A wide linear range of 1.00 × 10-14 to 1.00 × 10-4 M (R = 0.9953) was obtained under optimized conditions, and a detection limit (S/N = 3) was achieved of as low as 3.33 × 10-15 M. The proposed sensor also exhibited good stability and selectivity for the detection of copper ions. Finally, the analytical application of the proposed sensor was also evaluated using river water.
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Direct observation of the topological spin configurations mediated by the substitution of rare-earth element Y in MnNiGa alloy. NANOSCALE 2018; 10:2260-2266. [PMID: 29350742 DOI: 10.1039/c7nr08997j] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
The evolution of topological magnetic domains microscopically correlates the dynamic behavior of memory units in spintronic application. Nanometric bubbles with variation of spin configurations have been directly observed in a centrosymmetric hexagonal magnet (Mn0.5Ni0.5)65(Ga1-yYy)35 (y = 0.01) using Lorentz transmission electron microscopy. Magnetic bubbles instead of biskyrmions are generated due to the enhancement of quality factor Q caused by the substitution of rare-earth element Y. Furthermore, the bubble density and diversified spin configurations are systematically manipulated via combining the electric current with perpendicular magnetic fields. The magnetic bubble lattice at zero field is achieved after the optimized manipulation.
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Oxygen defect engineering by the current effect assisted with temperature cycling in a perovskite-type La 0.7Sr 0.3CoO 3 film. NANOSCALE 2017; 9:13214-13221. [PMID: 28853487 DOI: 10.1039/c7nr03162a] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Introducing and modulating the oxygen deficiency concentration have been received as an effective way to obtain high catalytic activity in perovskite oxides. However, it is difficult to control the oxygen vacancy in conventional oxygen defect engineering due to harsh reaction conditions at elevated temperatures and the reducing atmosphere, which make it impractical for many technological applications. Herein, we report a new approach to oxygen defect engineering based on the combination of the current effect and temperature cycling at low temperature. Our investigations revealed that the electrical conductivity of the (011)-La0.7Sr0.3CoO3/PMN-PT film changes continuously from metallicity to insulativity under repeated transport measurements below room temperature, which indicates the transformation of the Co4+ state to Co3+ in the film. Further experiments and analysis revealed that oxygen vacancies can be well regulated by the combined current effect and temperature cycling in repeated measurements, which results in a decrease of Co4+/Co3+ and thus the remarkable variation of conductive properties of the film. Our work provides a simple and highly efficient method to engineer oxygen vacancies in perovskite-type oxides and brings new opportunities in designing high-efficiency oxidation catalysts.
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Wnt1 and SFRP1 as potential prognostic factors and therapeutic targets in cutaneous squamous cell carcinoma. GENETICS AND MOLECULAR RESEARCH 2016; 15:gmr8187. [PMID: 27420949 DOI: 10.4238/gmr.15028187] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
The Wnt signaling pathway plays a key role in insurgence and progression of many different forms of cancer. Some crucial components of the Wnt pathway have been proposed to be novel targets for cancer therapy. To date, the Wnt signaling pathway has not been studied in cutaneous squamous cell carcinoma (CSCC). This study was designed to investigate the expression of Wnt1 and SFRP1 from the Wnt pathway in CSCC. Tissue samples were obtained from 35 patients with CSCC and 30 controls admitted to the Xinjiang Uygur Autonomous Region People's Hospital at Urumchi City, China. Gene and protein expressions of Wnt1 and SFRP1 were quantified by immunohistochemistry and western blotting. Wnt1 expression was significantly higher (P < 0.05) in CSCC samples than in normal skin cells of the control subjects; in contrast, SFRP1 expression was significantly lower in CSCC tissues than that in tissues of control subjects (P < 0.05). Moreover, Wnt1 expression (P < 0.05) was found to be correlated with histopathological differentiation in CSCC, and negatively correlated with SFRP1 expression in CSCC (rs = -0.473, P = 0.015). Therefore, we concluded that Wnt1 and SFRP1 play important roles in the development of CSCC and could be potent markers for diagnosis, prevention, and therapy of CSCC.
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Shape-controlled ceria-reduced graphene oxide nanocomposites toward high-sensitive in situ detection of nitric oxide. Biosens Bioelectron 2015; 70:310-7. [PMID: 25840016 DOI: 10.1016/j.bios.2015.03.056] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2015] [Revised: 03/22/2015] [Accepted: 03/23/2015] [Indexed: 12/27/2022]
Abstract
Nitric oxide (NO) is an important signal molecule released by most cancer cells under drug stimulation or/and disease development but it is extremely challenging to in situ while real-time sensitively detect NO due to its large diffusivity, low concentration and fast decay. Herein, shape-controlled reduced graphene oxide nanocomposing with ceria (rGO-CeO2) was synthesized via hydrothermal reaction to construct a highly sensitive real-time sensing platform for NO detection. The crystal shape of CeO2 nanoparticles in rGO-CeO2 composites significantly affects the sensing performance of rGO-CeO2, of which the regular hexagonal nanocrystal CeO2 achieves the highest sensitivity (1676.06 mA cm(-2) M(-1)), a wide dynamic range (18.0 nM to 5.6 µM) and a low detection limit (9.6 nM). This attributes to a synergical effect from high catalytic activity of the specifically shaped CeO2 nanocrystal and good conductivity/high surface area of rGO. This work demonstrates a way by rationally compose individual merit components while well control the nanostructure for a superior synergistic effect to build a smart sensing platform, while offering a great application potential to sensitively real-time detect NO released from living cells for diagnosis or/and studies of complicated biological processes.
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Involvement of superoxide and nitric oxide in BRAF(V600E) inhibitor PLX4032-induced growth inhibition of melanoma cells. Integr Biol (Camb) 2014; 6:1211-7. [PMID: 25363644 DOI: 10.1039/c4ib00170b] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
The BRAF(V600E) inhibitor PLX4032 (Vemurafenib) is an FDA-approved new drug for the treatment of metastatic melanomas, which specifically inhibits the RAS/MEK/ERK signaling pathway to control cell proliferation and adhesion. However, no study has been carried out to investigate the role of intracellular oxidative balance in PLX4032-induced tumor growth inhibition. Herein, for the first time, superoxide (O2˙(-)) and nitric oxide (NO) generated from PLX4032-challenged melanoma cells were monitored using electrochemical sensors and conventional fluorescein staining techniques. Impacts of superoxide dismutase (SOD) and NG-monomethyl-L-arginine monoacetate (L-NMMA), a nitric oxide synthase inhibitor, were also examined to demonstrate the specificity of ROS/NO generation and its biological consequences. PLX4032 specifically triggers production of O2˙(-) and NO from BRAF(V600E) mutant A375 cells. SOD and L-NMMA could abolish the PLX4032-induced increase in intracellular O2˙(-) and NO production, thereby rescuing cell growth in BRAF mutant A375 cells (A375(BRAFV600E)). In addition, PLX4032 treatment could decrease the mitochondrial membrane potential in A375(BRAFV600E) cells. The results suggest that PLX4032 can selectively cause ROS production and depolarization of mitochondrial membranes, potentially initiating apoptosis and growth inhibition of PLX4032-sensitive cells. This work not only proposes a new mechanism for PLX4032-induced melanoma cell inhibition, but also highlights potential applications of electrochemical biosensors in cell biology and drug screening.
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The Construction of Glucose Biosensor Based on Platinum Nanoclusters—Multiwalled Carbon Nanotubes Nanocomposites. Appl Biochem Biotechnol 2012; 166:889-902. [DOI: 10.1007/s12010-011-9478-6] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2011] [Accepted: 11/29/2011] [Indexed: 10/14/2022]
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Synthesis and in vitro anti-cancer evaluation of tamoxifen-loaded magnetite/PLLA composite nanoparticles. Biomaterials 2006; 27:5725-33. [PMID: 16890989 DOI: 10.1016/j.biomaterials.2006.07.014] [Citation(s) in RCA: 111] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2006] [Accepted: 07/13/2006] [Indexed: 10/24/2022]
Abstract
The present study deals with the synthesis and characterization of tamoxifen-loaded magnetite/poly(l-lactic acid) composite nanoparticles (TMCN), and their in vitro anti-cancer activity against MCF-7 breast cancer cells. The composite nanoparticles with an average size of approximately 200 nm, were synthesized via a solvent evaporation/extraction technique in an oil/water emulsion. The superparamagnetic property (saturation magnetization value of approximately 7 emu/g) of the TMCN is provided by Fe(3)O(4) nanoparticles of approximately 6 nm encapsulated in the poly(l-lactic acid) matrix. The encapsulation efficiency of the Fe(3)O(4) and tamoxifen as a function of the concentration in the organic phase was investigated. The uptake of TMCN and tamoxifen by MCF-7 was estimated from the intracellular iron concentration. After 4h incubation of MCF-7 with TMCN, significant changes in the cell morphology were discernible from phase contrast microscopy. Cytotoxicity assay shows that while the Fe(3)O(4)-loaded poly(l-lactic acid) composite nanoparticles exhibit no significant cytotoxicity against MCF-7, approximately 80% of the these cells were killed after incubation for 4 days with TMCN.
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Antibacterial and antifungal efficacy of surface functionalized polymeric beads in repeated applications. Biotechnol Bioeng 2005; 89:474-84. [PMID: 15609269 DOI: 10.1002/bit.20384] [Citation(s) in RCA: 60] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
A simple method was developed to prepare polymeric microbeads with antibacterial and antifungal properties. The microbeads of approximately spherical shape and narrow size distribution were prepared from a mixture of poly (4-vinyl pyridine) (P4VP) and poly (vinylidene fluoride) (PVDF) by a phase inversion technique and subsequently derivatized with alkyl bromides having 4-10 carbon atoms. The quaternization of the pyridine groups into pyridinium groups confers the surface with highly effective and long-lasting antibacterial and antifungal properties, as shown by the effect on Escherichia coli and Aspergillus niger. Upon contact with the N-alkylated beads, the bacteria and fungal spores are lysed and intracellular constituents leach out into the medium. The efficacy of the alkyl chains in disrupting the cell membrane was investigated. The stability of the functional group and microbiocidal effectiveness of the microbeads in repeated applications was also assessed.
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[Diagnosis of schistosomiasis with gastroscope in 3 patients]. ZHONGGUO JI SHENG CHONG XUE YU JI SHENG CHONG BING ZA ZHI = CHINESE JOURNAL OF PARASITOLOGY & PARASITIC DISEASES 2003; 19:254. [PMID: 12571980] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/28/2023]
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Abstract
OBJECTIVE Estrogen-dependent growth of breast cancer can be blocked by anti-estrogens. Estrogen receptor (ER) presence in breast cancer implies responsiveness to endocrine therapy. However, for those patients who ultimately develop resistance to endocrine therapy, the mechanisms remain unclear. The present study attempted to compare the expression status of ER mRNA in a series of primary breast tumors with matched metastases and explored the relation between ER and mutant p53 expression. METHODS In situ hybridization using a digoxigenin-labeled estrogen receptor cDNA probe was employed to determine the expression of ER mRNA in 52 cases of primary tumors and their matched axillary lymph node metastases. Immunohistochemical staining using a monoclonal antibody against ER was also performed. RESULTS ER expression was observed in 53.8% (28/52) of primary tumors and 48% (25/52) of metastases, while 57.7% (30/52) of primary tumors and 53.8% (28/52) of metastases showed ER mRNA positivity. There were variations in ER status between in situ hybridization and immunohistochemistry measurements and between primary tumors and metastases. Mutant p53 expression was inversely associated with ER-negative, high-grade tumors. CONCLUSIONS In situ hybridization may be a more specific and sensitive method for determination of ER status than immunohistochemistry. It is possible that the biologic properties of ER change, and these changes may influence tumor response to endocrine therapy. In view of the ER variation, it was suggested that the ER status of metastatic tumors in addition to primary tumors should be taken into consideration in order to better determine the benefit of clinical endocrine therapy.
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Comment on "Direct measurement of the 'Giant' adiabatic temperature change in Gd5Si2Ge2". PHYSICAL REVIEW LETTERS 2000; 85:4191-4192. [PMID: 11056659 DOI: 10.1103/physrevlett.85.4191] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/14/2000] [Indexed: 05/23/2023]
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