The low hydrogen adsorption free energy and strong acid/alkaline resistance of layered MoS2 render it an excellent pH‐universal electrocatalyst for hydrogen evolution reaction (HER). However, the ...catalytic activity is dominantly suppressed by its limited active‐edge‐site density. Herein, a new strategy is reported for making a class of strongly coupled MoS2 nanosheet–carbon macroporous hybrid catalysts with engineered unsaturated sulfur edges for boosting HER catalysis by controlling the precursor decomposition and subsequent sodiation/desodiation. Both surface chemical state analysis and first‐principles calculations verify that the resultant catalysts exhibit a desirable valence‐electron state with high exposure of unsaturated sulfur edges and an optimized hydrogen adsorption free energy, significantly improving the intrinsic HER catalytic activity. Such an electrocatalyst exhibits superior and stable catalytic activity toward HER with small overpotentials of 136 mV in 0.5 m H2SO4 and 155 mV in 1 m KOH at 10 mA cm−2, which is the best report for MoS2–C hybrid electrocatalysts to date. This work paves a new avenue to improve the intrinsic catalytic activity of 2D materials for hydrogen generation.
A class of strongly coupled MoS2 nanosheet–carbon macroporous hybrids with engineered unsaturated sulfur edges has been developed as excellent hydrogen evolution reaction (HER) electrocatalysts. Both experimental analysis and first‐principles calculations verify that the resultant catalysts exhibit high exposure of unsaturated sulfur edges and an optimized hydrogen adsorption free energy, greatly boosting the HER activity and durability in acidic and alkaline media.
Developing low-cost and efficient electrocatalysts to accelerate oxygen evolution reaction (OER) kinetics is vital for water and carbon-dioxide electrolyzers. The fastest-known water oxidation ...catalyst, Ni(Fe)O
H
, usually produced through an electrochemical reconstruction of precatalysts under alkaline condition, has received substantial attention. However, the reconstruction in the reported catalysts usually leads to a limited active layer and poorly controlled Fe-activated sites. Here, we demonstrate a new electrochemistry-driven F-enabled surface-reconstruction strategy for converting the ultrathin NiFeO
F
nanosheets into an Fe-enriched Ni(Fe)O
H
phase. The activated electrocatalyst shows a low OER overpotential of 218 ± 5 mV at 10 mA cm
and a low Tafel slope of 31 ± 4 mV dec
, which is among the best for NiFe-based OER electrocatalysts. Such superior performance is caused by the effective formation of the Fe-enriched Ni(Fe)O
H
active-phase that is identified by
Raman spectroscopy and the substantially improved surface wettability and gas-bubble-releasing behavior.
Abstract
Critical barriers to layered Ni-rich cathode commercialisation include their rapid capacity fading and thermal runaway from crystal disintegration and their interfacial instability. ...Structure combines surface modification is the ultimate choice to overcome these. Here, a synchronous gradient Al-doped and LiAlO
2
-coated LiNi
0.9
Co
0.1
O
2
cathode is designed and prepared by using an oxalate-assisted deposition and subsequent thermally driven diffusion method. Theoretical calculations, in situ X-ray diffraction results and finite-element simulation verify that Al
3+
moves to the tetrahedral interstices prior to Ni
2+
that eliminates the Li/Ni disorder and internal structure stress. The Li
+
-conductive LiAlO
2
skin prevents electrolyte penetration of the boundaries and reduces side reactions. These help the Ni-rich cathode maintain a 97.4% cycle performance after 100 cycles, and a rapid charging ability of 127.7 mAh g
−1
at 20 C. A 3.5-Ah pouch cell with the cathode and graphite anode showed more than a 500-long cycle life with only a 5.6% capacity loss.
•Emerging anion-exchange membrane water electrolysis (AEMWE) is introduced.•Transition metal-based powder and self-supporting catalysts for AEMWE are summed.•A detailed guideline for establishing the ...AEMWE testing system is provided.•Advanced electrochemical methods to evaluate the AEMWE performance are elaborated.
Green hydrogen produced by water electrolysis is one of the most promising technologies to realize the efficient utilization of intermittent renewable energy and the decarbonizing future. Among various electrolysis technologies, the emerging anion-exchange membrane water electrolysis (AEMWE) shows the most potential for producing green hydrogen at a competitive price. In this review, we demonstrate a comprehensive introduction to AEMWE including the advanced electrode design, the lab-scaled testing system establishment, and the electrochemical performance evaluation. Specifically, recent progress in developing high activity transition metal-based powder electrocatalysts and self-supporting electrodes for AEMWE is summarized. To improve the synergistic transfer behaviors between electron, charge, water, and gas inside the gas diffusion electrode (GDE), two optimizing strategies are concluded by regulating the pore structure and interfacial chemistry. Moreover, we provide a detailed guideline for establishing the AEMWE testing system and selecting the electrolyzer components. The influences of the membrane electrode assembly (MEA) technologies and operation conditions on cell performance are also discussed. Besides, diverse electrochemical methods to evaluate the activity and stability, implement the failure analyses, and realize the in-situ characterizations are elaborated. In end, some perspectives about the optimization of interfacial environment and cost assessments have been proposed for the development of advanced and durable AEMWE.
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The design and engineering of multifunctional nanostructures with multiple components and synergistic properties are in urgent demand for variety of acceptable biosensing platforms, enabling users to ...fulfill multiple tasks in a single nanosystem. Herein, we report using an asymmetric hematite–silica hybrid of Janus γ-Fe2O3/SiO2 nanoparticles (JFSNs) as a multifunctional biosensing platform for sensitive colorimetric detection of H2O2 and glucose. It was demonstrated that JFSNs exhibit an intrinsic peroxidase-like catalytic activity. Compared with natural enzyme, JFSNs nanoenzymes could be used over a wider range of pH and temperatures and were more stable over time. Importantly, besides its excellent catalytic activity, the asymmetric properties of the Janus nanoparticle enable it to form the multiple functional utilities for various biosensing applications, including the ease of surface modification without deactivation of catalytic activity and recoverable use by magnetic separation. Thus, we utilized JFSNs with glucose oxidase (GOx) immobilization for glucose-sensitive colorimetric detection, which exhibited both catalytic activity of glucose oxidase and peroxidase with high selectivity and acceptable reproducibility. By combining these two analysis systems into Janus particles, an all-in-one and reusable sensor for blood glucose was formed and has the capability for determination of glucose in complex samples such as serum. These results suggest that such Janus nanosystems have the potential to construct robust nanoarchitecture with multiple functionalities for various biosensing applications.
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•Rapid low-temperature synthesis of hollow CuS0.55 nanoparticles has been shown.•The hollow nanostructure greatly improves electrochemically active surface area.•The rich Cu sites ...show strong adsorption ability to targeted OOH∗ intermediates.•An ultralow overpotential is required for water oxidation in alkaline media.
Developing low-cost and binder-free Cu-based electrocatalysts for high-performance oxygen evolution reactions (OER) is of great importance to promote their practical applications. Herein, we demonstrate the low-temperature and rapid synthesis of hollow CuS0.55 nanoparticles on a Cu foam as highly active OER electrocatalysts through an anodic oxidation electrodeposition technique. The large electrochemically active surface area and strong adsorption ability of Cu sites to targeted OOH∗ intermediates are beneficial for enhancing catalytic properties. As a consequence, the hollow CuS0.55 nanoparticles exhibit an ultralow overpotential of 386 mV to achieve a high current density of 100 mA cm−2 in alkaline media with a very small Tafel slope of 33 mV dec−1, which is among the best reported for Cu-based electrocatalysts. The turnover frequency (TOF) is approximately 6 times higher than those of the corresponding CuS0.57 and CuO catalysts. This work provides a simple and feasible approach that can be scaled up easily to construct low-cost and efficient Cu-based OER electrocatalysts.
Postoperative pneumonia is the third most common complication after surgery, and its occurrence is associated with a poor prognosis in patients. Perioperative chlorhexidine oral care has been ...reported to reduce the incidence of postoperative pneumonia in patients undergoing cardiac surgery. However, whether perioperative chlorhexidine oral care can reduce the incidence of postoperative pneumonia in noncardiac surgical patients is still unknown. The aim of this systematic review and meta-analysis was to determine the association between perioperative chlorhexidine oral care and postoperative pneumonia in noncardiac surgical patients.
A comprehensive systematic search of PubMed, Ovid Embase, Web of Science, the Cochrane Library, Wanfang Database, and the China National Knowledge Infrastructure was conducted to include studies from the inception of each database through March 2021. The reference lists of all included studies were also searched by hand. Eligible studies were published and unpublished randomized controlled trials and observational studies evaluating the effect of perioperative chlorhexidine oral care on the reported incidence of postoperative pneumonia. Relative risks or odds ratio with their 95% confidence intervals were calculated and risk of bias was assessed for eligible studies.
Seven randomized controlled trials with a total of 1,773 patients and 3 observational studies with a total of 12,528 noncardiac surgical patients were included. A total of 621 and 5,904 patients received perioperative chlorhexidine oral care in randomized controlled trials and observational studies, respectively. Six (85%) randomized controlled trials had a high risk of bias, and 2 (67%) observational studies had a high quality. Perioperative chlorhexidine oral care significantly reduced the incidence of postoperative pneumonia in randomized controlled trials (relative risk, 0.60; 95% confidence interval, 0.44–0.80; P < .001) and observational studies (odds ratio, 0.26; 95% confidence interval, 0.08–0.90; P = .03).
Perioperative chlorhexidine oral care led by a nurse significantly decreases the incidence of postoperative pneumonia in noncardiac surgical patients and may be more convenient and economical compared with dental professional-led perioperative oral care.
Abstract
Background
The weight-adjusted waist index (WWI) is a new measure of obesity, and this study aimed to determine the association between the WWI and stroke.
Methods
Using the National Health ...and Nutrition Examination Survey (NHANES) 2011–2020 dataset, cross-sectional data from 23,389 participants were analysed. The correlation between the WWI and stroke was investigated through multivariate logistic regression and smoothing curve fitting. Subgroup analysis and interaction tests were also carried out.
Results
The research involved 23,389 participants, of whom 893 (3.82%) had a stroke. The fully adjusted model revealed a positive correlation between the WWI and stroke 1.25 (1.05, 1.48). Individuals who were in the highest quartile of WWI exhibited a 62% higher likelihood of experiencing a stroke than those in the lowest quartile 1.62 (1.06, 2.48). Subgroup analysis and interaction tests revealed that this positive correlation was similar in different population settings (all P for interaction > 0.05).
Conclusion
A higher WWI was associated with a higher prevalence of stroke. The results of this study underscore the value of the WWI in stroke prevention and management.
Layered oxide cathodes with high Ni content promise high energy density and competitive cost for Li-ion batteries (LIBs). However, Ni-rich cathodes suffer from irreversible interface reconstruction ...and undesirable cracking with severe performance degradation upon long-term operation, especially at elevated temperatures. Herein, we demonstrate in situ surface engineering of Ni-rich cathodes to construct a dual ion/electron-conductive NiTiO3 coating layer and Ti gradient doping (NC90–Ti@NTO) in parallel. The dual-modification synergy helps to build a thin, robust cathode–electrolyte interface with rapid Li-ion transport and enhanced reaction kinetics, and effectively prevents unfavorable crystalline phase transformation during long-term cycling under harsh environments. The optimized NC90–Ti@NTO delivers a high reversible capacity of 221.0 mAh g−1 at 0.1C and 158.9 mAh g−1 at 10C. Impressively, it exhibits a capacity retention of 88.4% at 25 °C after 500 cycles and 90.7% at 55 °C after 300 cycles in a pouch-type full battery. This finding provides viable clues for stabilizing the lattice and interfacial chemistry of Ni-rich cathodes to achieve durable LIBs with high energy density.
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•NiTiO3 coating and Ti gradient doping of LiNi0.9Co0.1O2 are realized.•This dual modification of LiNi0.9Co0.1O2 stabilizes the lattice and interfacial chemistry.•The optimized sample exhibits a high specific capacity of 158.9 mAh g−1 at 10C.
The clinical application of lung cancer detection based on breath test is still challenging due to lack of predictive molecular markers in exhaled breath. This study explored potential lung cancer ...biomarkers and their related pathways using a typical process for metabolomics investigation.
Breath samples from 60 lung cancer patients and 176 healthy people were analyzed by GC-MS. The original data were GC-MS peak intensity removing background signal. Differential metabolites were selected after univariate statistical analysis and multivariate statistical analysis based on OPLS-DA and Spearman rank correlation analysis. A multivariate PLS-DA model was established based on differential metabolites for pattern recognition. Subsequently, pathway enrichment analysis was performed on differential metabolites.
The discriminant capability was assessed by ROC curve of whom the average AUC and average accuracy in 100-fold cross validations were 0.871 and 0.787, respectively. Eight potential biomarkers were involved in a total of 18 metabolic pathways. Among them, 11 metabolic pathways have p-value smaller than .1.
Some pathways among them are related to risk factors or therapies of lung cancer. However, more of them are dysregulated pathways of lung cancer reported in studies based on genome or transcriptome data.
We believe that it opens the possibility of using metabolomics methods to analyze data of exhaled breath and promotes involvement of knowledge dataset to cover more volatile metabolites.
Although a series of related research reported diagnostic models with highly sensitive and specific prediction, the clinical application of lung cancer detection based on breath test is still challenging due to disease heterogeneity and lack of predictive molecular markers in exhaled breath. This study may promote the clinical application of this technique which is suitable for large-scale screening thanks to its low-cost and non-invasiveness. As a result, the mortality of lung cancer may be decreased in future.
Key messages
In the present study, 11 pathways involving 8 potential biomarkers were discovered to be dysregulated pathways of lung cancer.
We found that it is possible to apply metabolomics methods in analysis of data from breath test, which is meaningful to discover convinced volatile markers with definite pathological and histological significance.
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