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•Doping Co2+/3+ to NiFe-LDH reduces the OER overpotential on (001) and (110) planes.•Fe3+ in NiCo2+Fe-LDH and Co3+ in NiCo3+Fe-LDH are identified as OER active sites.•Co3+-doped ...NiFe-LDH has a lower OER overpotential than Co2+-doped NiFe-LDH.•The improved activity is attributed to the tailored electron density of metal site.
NiFe-layered double hydroxide (NiFe-LDH) has been widely accepted as promising catalyst candidates for the oxygen evolution reaction (OER). Recently, incorporating Co atoms in NiFe laminates has been recognized as an effective way to enhance the OER activity, but their roles have been rarely studied. Herein, density functional theory plus U (DFT + U) calculations are employed to evaluate the OER thermodynamics after introducing bivalent Co2+ or trivalent Co3+ and consequent sites sensitivity in NiFe-LDH catalyst. Generally, based on computational results, incorporation of Co2+/Co3+ into NiFe-LDH could modulate the electronic structure of metal sites and thus reducing their OER overpotential. Moreover, Co3+-doped NiFe-LDH has the lowest overpotential of η = 0.413 eV among the above proposed structure. This point was fully demonstrated by Co2+ and Co3+-incorporated NiFe-LDH nanosheets made by a co-precipitation method, by showing OER onset overpotential of 249 mV for Co3+-doped NiFe-LDH, 264 mV for Co2+-doped NiFe-LDH, which are 33 mV and 18 mV lower than that of pristine NiFe-LDH (282 mV), respectively. Such improved OER activity were attributed to the lowered overpotential at the *OOH formation step for Co2+-doped NiFe-LDH and the deprotonation step for Co3+-doped NiFe-LDH, which was the potential limiting step for their OER process. This work should be inspiring for future designing of more efficient NiFe-based oxygen evolution electrocatalysts.
For conceptual analysis of the principle of relay vibration protection, this article establishes the simulation system model of directional current protection in MATLAB/Simulink environment through ...the protection algorithm. Various outcomes have been achieved for the proposed approach during the faulty conditions. The outcomes obtained during the fault period reveals that the waveform of three-phase current changes greatly, and the amplitude of three-phase current at power supply side increases sharply. After 0.02s signal acquisition and processing, the action signal acts after 0.07s, and the fault is removed. In case of two-phase short-circuit, two-phase grounding short-circuit and other faults, the fault can be removed smoothly after signal acquisition and processing. In this paper, the directional current protection simulation system based on microcomputer protection model is built, and the changes of voltage, current and action signal are demonstrated through GUI interface, and analyzed and verified.
Influenza viruses infect millions of people around the globe annually, usually causing self-limited upper respiratory tract infections. However, a small but non-negligible proportion of patients ...suffer from life-threatening pulmonary disease. Those affected include otherwise healthy individuals, and children with primary infections in particular. Much effort has been devoted to virological studies of influenza and vaccine development. By contrast, the enormous interindividual variability in susceptibility to influenza has received very little attention. One interesting hypothesis is that interindividual variability is driven largely by the genetic makeup of the infected patients. Unbiased genomic approaches have been used to search for genetic lesions in children with life-threatening pulmonary influenza. Four monogenic causes of severe influenza pneumonitis—deficiencies of GATA2, IRF7, IRF9, and TLR3—have provided evidence that severe influenza pneumonitis can be genetic and often in patients with no other severe infections. These deficiencies highlight the importance of human type I and III IFN-mediated immunity for host defense against influenza. Clinical penetrance is incomplete, and the underlying mechanisms are not yet understood. However, human genetic studies have clearly revealed that seemingly sporadic and isolated life-threatening influenza pneumonitis in otherwise healthy individuals can be genetic.
Searching the cost‐effective organic semiconductors is strongly needed in order to facilitate the practice of organic solar cells (OSCs), yet to be fulfilled. Herein, we have succeeded in developing ...two non‐fused ring electron acceptors (NFREAs), leading to the highest efficiency of 16.2 % for the NFREA derived OSCs. These OSCs exhibit the superior operational stabilities under one sun equivalent illumination without ultraviolet (UV) filtration. It is revealed that the modulation of halogen substituents on aromatic side chains, as the new structural tool to tune the intermolecular interaction and optoelectronic properties of acceptors, not only promotes the interlocked tic‐tac‐toe frame of three‐dimensional stacks in solid, but also improves charge dynamics of acceptors to enable high‐performance and stable OSCs.
Two non‐fused ring electron acceptors (NFREAs) have been developed. The halogen substituents on the aromatic side chains, as the new structure design tools, not only facilitate the construction of 3D stacks in solid, but also optimize the optoelectronic properties of the NFREAs, leading to organic solar cells with 16.2 % efficiency and excellent operational stability.
Mariculture is a well-known high-risk industry. However, mariculture insurance, which is an important risk management tool, is facing serious market failure. An important reason for this market ...failure lies in the unsound premium rate and pricing method. Due to a lack of long-term yield data, empirical rates are often adopted, but this adoption can lead to a high loss ratio. This paper provides an improved method for premium computation of mariculture insurance using an information diffusion model (IDM). An example of oyster insurance in China shows that, compared with the traditional pricing approach, the IDM can greatly improve the accuracy and stability of premium rate calculations, especially in cases of small samples.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Unprecedented measures have been adopted to control the rapid spread of the ongoing COVID-19 epidemic in China. People's adherence to control measures is affected by their knowledge, attitudes, and ...practices (KAP) towards COVID-19. In this study, we investigated Chinese residents' KAP towards COVID-19 during the rapid rise period of the outbreak. An online sample of Chinese residents was successfully recruited via the authors' networks with residents and popular media in Hubei, China. A self-developed online KAP questionnaire was completed by the participants. The knowledge questionnaire consisted of 12 questions regarding the clinical characteristics and prevention of COVID-19. Assessments on residents' attitudes and practices towards COVID-19 included questions on confidence in winning the battle against COVID-19 and wearing masks when going out in recent days. Among the survey completers (n=6910), 65.7% were women, 63.5% held a bachelor degree or above, and 56.2% engaged in mental labor. The overall correct rate of the knowledge questionnaire was 90%. The majority of the respondents (97.1%) had confidence that China can win the battle against COVID-19. Nearly all of the participants (98.0%) wore masks when going out in recent days. In multiple logistic regression analyses, the COVID-19 knowledge score (OR: 0.75-0.90, P<0.001) was significantly associated with a lower likelihood of negative attitudes and preventive practices towards COVID-2019. Most Chinese residents of a relatively high socioeconomic status, in particular women, are knowledgeable about COVID-19, hold optimistic attitudes, and have appropriate practices towards COVID-19. Health education programs aimed at improving COVID-19 knowledge are helpful for Chinese residents to hold optimistic attitudes and maintain appropriate practices. Due to the limited sample representativeness, we must be cautious when generalizing these findings to populations of a low socioeconomic status.
Innate immune cells have complex signalling pathways for sensing pathogens and initiating innate immune responses against infection. These pathways are tightly regulated at different levels, ...including by epigenetic regulators. In this Review, we discuss studies revealing the epigenetic mechanisms, as well as the post-transcriptional and post-translational modifications by chromatin modifiers, that underlie the establishment of these signalling networks and the rapid induction of innate immune molecules during infection. We also discuss how pathogens use their own products, as well as host components, to target host epigenomes for immune evasion and survival. We describe the crosstalk between epigenetic regulators and new modulators, such as inflammation-specific metabolites, and how we might deconstruct dynamic chromatin patterns and identify critical chromatin modifiers of host-pathogen interactions.
The interesting and diverse biological activities of nitrogen-containing compounds make the construction of the C-N bond of great importance. Despite the tremendous advances that have been made in ...this research field, C-N bond formation based on nitrogen-centered radicals remains a significant challenge due to the harsh conditions required for the generation of nitrogen-centered radicals and their propensity for hydrogen abstraction or engaging in other degradation pathways. In the past several years, novel methodologies for C-N bond constructions based on nitrogen centered-radical intermediates, coordinated with metal or generated in the presence of visible-light and a photocatalyst, have attracted considerable attention. This tutorial review will summarize the significant progress of these efficient and mild radical amination reactions, with an emphasis on approaches for the generation of nitrogen-centered radicals and their reaction patterns, related mechanisms and synthetic applications, as well as unmet challenges in this emerging and promising field.
Recent advances in promising metal-catalyzed and visible-light initiated radical amination reactions are reviewed.
Hydrogen Sulfide Biology and Its Role in Cancer Khattak, Saadullah; Rauf, Mohd Ahmar; Khan, Nazeer Hussain ...
Molecules (Basel, Switzerland),
05/2022, Letnik:
27, Številka:
11
Journal Article
Recenzirano
Odprti dostop
Hydrogen sulfide (H
S) is an endogenous biologically active gas produced in mammalian tissues. It plays a very critical role in many pathophysiological processes in the body. It can be endogenously ...produced through many enzymes analogous to the cysteine family, while the exogenous source may involve inorganic sulfide salts. H
S has recently been well investigated with regard to the onset of various carcinogenic diseases such as lung, breast, ovaries, colon cancer, and neurodegenerative disorders. H
S is considered an oncogenic gas, and a potential therapeutic target for treating and diagnosing cancers, due to its role in mediating the development of tumorigenesis. Here in this review, an in-detail up-to-date explanation of the potential role of H
S in different malignancies has been reported. The study summarizes the synthesis of H
S, its roles, signaling routes, expressions, and H
S release in various malignancies. Considering the critical importance of this active biological molecule, we believe this review in this esteemed journal will highlight the oncogenic role of H
S in the scientific community.
Antibiotics are widely used in humans and animals, but there is a big concern about their negative impacts on ecosystem and human health after use. So far there is a lack of information on emission ...inventory and environmental fate of antibiotics in China. We studied national consumption, emissions, and multimedia fate of 36 frequently detected antibiotics in China by market survey, data analysis, and level III fugacity modeling tools. Based on our survey, the total usage for the 36 chemicals was 92700 tons in 2013, an estimated 54000 tons of the antibiotics was excreted by human and animals, and eventually 53800 tons of them entered into the receiving environment following various wastewater treatments. The fugacity model successfully predicted environmental concentrations (PECs) in all 58 river basins of China, which are comparable to the reported measured environmental concentrations (MECs) available in some basins. The bacterial resistance rates in the hospitals and aquatic environments were found to be related to the PECs and antibiotic usages, especially for those antibiotics used in the most recent period. This is the first comprehensive study which demonstrates an alarming usage and emission of various antibiotics in China.
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