The commercial production of H2 from water splitting requires highly efficient, low-cost, and stable earth-abundant electrocatalysts to speed up the kinetics of hydrogen evolution reaction (HER). In ...this study, we proposed a concise and effective strategy for fabricating NiS electrocatalysts on Ni foam (NF) substrate to serve as HER electrocatalysts during potentiostatic electrodeposition. The NiS electrocatalyst shows a cauliflower-like surface morphology when the electrodeposition voltage is adjusted. The proposed electrocatalyst exhibits excellent HER performance with a low overpotential of 58 mV at 10 mA·cm−2 and a small Tafel slope of 81.6 mV·dec−1 in 1.0 M KOH solution. Such a high performance can be attributed to the amorphous phase structures, high conductivity, composition optimization, and the close combination between the electrocatalyst and NF. This study provides a facile, fast, and feasible avenue for developing highly efficient and affordable electrochemical catalysts for HER.
Aims
To explore the experiences of community‐dwelling older adults in Wuhan during the coronavirus disease 2019 lockdown.
Design
An empirical phenomenological approach was used to conduct a ...qualitative study.
Methods
We performed semi‐structured, in‐depth telephone interviews between July 24 and August 2, 2020. A purposive sample of 18 participants (≥65 years old) who lived in Wuhan during the lockdown was recruited, including both infected and uninfected people. Data summarization and theme categories refinement were performed following Colaizzi's phenomenological approach.
Results
Four main theme categories emerged. First, the ‘Challenges’ posed by the epidemic. Older adults were challenged with barriers in seeing a doctor and daily life inconveniences. And they experienced negative emotions, whether infected or not. The second domain was ‘multi‐dimensional support’, which helped older people went through the difficult period. The third domain was ‘resilience amid challenges’. Although they experienced physical and psychological distress, most of them could self‐adjust and achieve transcendence from the unique experience. Lastly, the remaining impact after the epidemic affected older adults. Some still had mental burdens, while others thought they have benefited from the quarantine time (e.g. regular diet, learning new skills).
Conclusion
The epidemic and lockdown of the city brought significant physical and mental challenges to community‐dwelling older adults. Active adaptation and multifaceted support helped them through this period. However, the mental burdens after the epidemic still require attention. These experiences would provide guidelines for the protection of vulnerable populations during public health emergencies.
Impact
The results of the study suggested that certain social dynamics and individual behaviours helped the elderly to better cope with the stressful lockdown period. The findings in this study provided guidelines on how to reduce the negative effects on older adults during the pandemic and enlighten studies concerning the well‐being of older adults or other vulnerable people in future crises.
In the food industry, manufacturers and customers have paid more attention to natural pigments instead of the synthetic counterparts for their excellent coloring ability and healthy properties. ...Microalgae are proven as one of the major photosynthesizers of naturally derived commercial pigments, gaining higher value in the global food pigment market. Microalgae-derived pigments, especially chlorophylls, carotenoids and phycobiliproteins, have unique colors and molecular structures, respectively, and show different physiological activities and health effects in the human body. This review provides recent updates on characteristics, application fields, stability in production and extraction processes of chlorophylls, carotenoids and phycobiliproteins to standardize and analyze their commercial production from microalgae. Potential food commodities for the pigment as eco-friendly colorants, nutraceuticals, and antioxidants are summarized for the target products. Then, recent cultivation strategies, metabolic and genomic designs are presented for high pigment productivity. Technical bottlenecks of downstream processing are discussed for improved stability and bioaccessibility during production. The production strategies of microalgal pigments have been exploited to varying degrees, with some already being applied at scale while others remain at the laboratory level. Finally, some factors affecting their global market value and future prospects are proposed. The microalgae-derived pigments have great potential in the food industry due to their high nutritional value and competitive production cost.
Heat-shock transcription factor 1 (HSF1) orchestrates the fast and vast cellular response to heat shock through increased expression of heat-shock proteins. However, how HSF1 rapidly and reversibly ...regulates transcriptional reprogramming remains poorly defined. Here by combining super-resolution imaging, in vitro reconstitution and high-throughput sequencing, we reveal that HSF1 forms small nuclear condensates via liquid-liquid phase separation at heat-shock-protein gene loci and enriches multiple transcription apparatuses through co-phase separation to promote the transcription of target genes. Furthermore, the phase-separation capability of HSF1 is fine-tuned through phosphorylation at specific sites within the regulatory domain. Last, we discovered that HSP70 disperses HSF1 condensates to attenuate transcription following the cessation of heat shock and further prevents the gel-like phase transition of HSF1 under extended heat-shock stress. Our work reveals an inducible and reversible phase-separation feedback mechanism for dynamic regulation of HSF1 activity to drive the transcriptional response and maintain protein homeostasis during acute stress.
The study of phosphorylase kinase (PhK)-regulated glycogen metabolism has contributed to the fundamental understanding of protein phosphorylation; however, the molecular mechanism of PhK remains ...poorly understood. Here we present the high-resolution cryo-electron microscopy structures of human muscle PhK. The 1.3-megadalton PhK α
β
γ
δ
hexadecamer consists of a tetramer of tetramer, wherein four αβγδ modules are connected by the central β
scaffold. The α- and β-subunits possess glucoamylase-like domains, but exhibit no detectable enzyme activities. The α-subunit serves as a bridge between the β-subunit and the γδ subcomplex, and facilitates the γ-subunit to adopt an autoinhibited state. Ca
-free calmodulin (δ-subunit) binds to the γ-subunit in a compact conformation. Upon binding of Ca
, a conformational change occurs, allowing for the de-inhibition of the γ-subunit through a spring-loaded mechanism. We also reveal an ADP-binding pocket in the β-subunit, which plays a role in allosterically enhancing PhK activity. These results provide molecular insights of this important kinase complex.
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•A facile and universal approach has been developed to synthesize yolk-shelled structures with controllable void space.•NxC coating enhances the structure stability and charge ...transfer of the yolk-shelled SnO2@NxC composite.•The novel structure with the inner shell and the core acting as active materials enhances the volumetric energy density;•The composite shows excellent stable cycling performance of 740 mAh g−1 after 750 cycles at 0.25C.
A facile and universal route has been developed to synthesize yolk-shelled metal oxides@N doped C spheres with controllable void size. Based on this approach, a yolk-shelled SnO2@N dopped C (yolk-shelled SnO2@NxC) composite has been successfully synthesized for lithium-ion battery electrodes. The reported yolk-shelled SnO2@NxC, with SnO2 as inner shell and core, can remarkably increase the volumetric energy density of electrodes. The void between shell and core could accommodate the volume expansion during lithiation. More importantly, the NxC outer layer as a framework maintains the structure's integrity and shortens the transmission distance of charges. The results confirm the much-improved electrochemical performance. The yolk-shelled SnO2@NxC electrode delivers excellent cycling stability of 740 mAh g−1 at a current density of 0.25C after 750 cycles and a superior rate performance of 500 mAh g−1 at 5C (1C = 800 mA g−1). In addition, some other yolk-shelled metal oxides such as yolk-shelled TiO2 and yolk-shelled Fe2O3 have also been directly synthesized through the method in this paper for their proper applications.
Detecting Violations of Differential Privacy Ding, Zeyu; Wang, Yuxin; Wang, Guanhong ...
Proceedings of the 2018 ACM SIGSAC Conference on Computer and Communications Security,
10/2018
Conference Proceeding
Odprti dostop
The widespread acceptance of differential privacy has led to the publication of many sophisticated algorithms for protecting privacy. However, due to the subtle nature of this privacy definition, ...many such algorithms have bugs that make them violate their claimed privacy. In this paper, we consider the problem of producing counterexamples for such incorrect algorithms. The counterexamples are designed to be short and human-understandable so that the counterexample generator can be used in the development process -- a developer could quickly explore variations of an algorithm and investigate where they break down. Our approach is statistical in nature. It runs a candidate algorithm many times and uses statistical tests to try to detect violations of differential privacy. An evaluation on a variety of incorrect published algorithms validates the usefulness of our approach: it correctly rejects incorrect algorithms and provides counterexamples for them within a few seconds.
Photothermal catalysis realizes the synergistic effect of solar energy and thermochemistry, which also has the potential to improve the reaction rate and optimize the selectivity. In this review, the ...research progress of photothermal catalytic removal of volatile organic compounds (VOCs) by nano-catalysts in recent years is systematically reviewed. First, the fundamentals of photothermal catalysis and the fabrication of catalysts are described, and the design strategy of optimizing photothermal catalysis performance is proposed. Second, the performance for VOC degradation with photothermal catalysis is evaluated and compared for the batch and continuous systems. Particularly, the catalytic mechanism of VOC oxidation is systematically introduced based on experimental and theoretical study. Finally, the future limitations and challenges have been discussed, and potential research directions and priorities are highlighted. A broad view of recent photothermal catalyst fabrication, applications, challenges, and prospects can be systemically provided by this review.
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•The fundamentals and design strategies of photothermal catalysts are concluded.•VOC photothermal performance is unified for comparison under different system.•The photothermal mechanisms in VOC oxidation are emphasized.•Potential research direction and challenge of photothermal catalysis are summarized.
•A thick TU1/316 L clad plate was constructed for nuclear fusion equipment.•Technical parameters of explosive welding were obtained and optimized by numerical calculations.•An efficient procedure was ...developed for explosion bonded TU1/316 L bimetallic plates.
TU1/316 l clad plates with a high thickness are used in nuclear fusion equipment as coil terminals. The technical specifications of clad plates for nuclear fusion equipment, such as the composite ratio, tensile strength, shear strength and scale of the interfacial wave, are significantly higher than those of clad plates for conventional applications. It is difficult to produce high-quality clad plates through explosive welding experiments alone. To manufacture high-quality TU1/316 L clad plates, the technical parameters of the explosive welding process were obtained and optimized by theoretical analysis and numerical calculations. A procedure for fabricating explosion bonded TU1/316 L clad plates was successfully determined through the combination of numerical calculations and experiments, and the bimetallic plates were used to manufacture international thermonuclear experimental reactor (ITER) components.
Human and animal studies have shown that the colonic concentrations of lipid peroxidation products, such as 4-hydroxynonenal (4-HNE), are elevated in inflammatory bowel disease (IBD). However, the ...actions and mechanisms of these compounds on the development of IBD are unknown. Here, we show that a systemic treatment of low-dose 4-HNE exacerbates dextran sulfate sodium (DSS)-induced IBD in C57BL/6 mice, suggesting its pro-IBD actions in vivo. Treatment with 4-HNE suppressed colonic expressions of tight-junction protein occludin, impaired intestinal barrier function, enhanced translocation of lipopolysaccharide (LPS) and bacterial products from the gut into systemic circulation, leading to increased activation of Toll-like receptor 4 (TLR4) signaling in vivo. Furthermore, 4-HNE failed to promote DSS-induced IBD in Tlr4-/- mice, supporting that TLR4 signaling contributes to the pro-IBD effects of 4-HNE. Together, these results suggest that 4-HNE exacerbates the progression of IBD through activation of TLR4 signaling, and therefore could contribute to the pathogenesis of IBD.
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•4-hydroxynonenal (4-HNE) exaggerates colonic inflammation in mice.•4-HNE increases concentrations of LPS and bacterial products in the circulation, leading to enhanced activation of TLR4 signaling in vivo.•The pro-inflammatory effects of 4-HNE were abolished in Tlr4-/- mice.
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