The significance of identifying the fundamental mechanism of interactions between adjacent catalytic active centers has long been underestimated. Utilizing density functional theory calculations, we ...demonstrate controllable cooperative interaction between two nearby Fe centers embedded on nitrogenated graphene aided by CO adsorption. The interconnected adjacent Fe atoms respond cooperatively to CO molecules with communicative structural self-adaption and electronic transformation. The adsorbed CO changes not only the spin of the active site it is attached to but also that of its adjacent site. Consequently, the two adjacent Fe atoms feature unique oscillatory long-range spin coupling. Our theoretical investigation suggests cooperative communication between adjacent active sites on a single-atom catalyst is nontrivial.
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IJS, KILJ, NUK, PNG, UL, UM
Boundary conduction mode (BCM) and discontinuous conduction mode (DCM) control strategies are widely used for the flyback microinverter. The BCM and DCM control strategies are investigated for the ...interleaved flyback microinverter concentrating on the loss analysis under different load conditions. These two control strategies have different impact on the loss distribution and thus the efficiency of the flyback microinverter. For the interleaved flyback microinverter, the dominant losses with heavy load include the conduction loss of the power MOSFETs and diodes, and the loss of the transformer; while the dominant losses with light load include the gate driving loss, the turn-off loss of the power MOSFETs and the transformer core loss. Based on the loss analysis, a new hybrid control strategy combing the two-phase DCM and one-phase DCM control is proposed to improve the efficiency in wide load range by reducing the dominant losses depending on the load current. The optimal design method based on the boundary condition of the hybrid control is also presented. The experimental results verify the benefits of the proposed control.
Background and Aims
Coronavirus disease 2019 (COVID‐19) is a new infectious disease. To reveal the hepatic injury related to this disease and its clinical significance, we conducted a multicenter ...retrospective cohort study that included 5,771 adult patients with COVID‐19 pneumonia in Hubei Province.
Approach and Results
We reported the distributional and temporal patterns of liver injury indicators in these patients and determined their associated factors and death risk. Longitudinal liver function tests were retrospectively analyzed and correlated with the risk factors and death. Liver injury dynamic patterns differed in alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP), and total bilirubin (TBIL). AST elevated first, followed by ALT, in severe patients. ALP modestly increased during hospitalization and largely remained in the normal range. The fluctuation in TBIL levels was mild in the non‐severe and the severe groups. AST abnormality was associated with the highest mortality risk compared with the other indicators of liver injury during hospitalization. Common factors associated with elevated liver injury indicators were lymphocyte count decrease, neutrophil count increase, and male gender.
Conclusion
The dynamic patterns of liver injury indicators and their potential risk factors may provide an important explanation for the COVID‐19‐associated liver injury. Because elevated liver injury indicators, particularly AST, are strongly associated with the mortality risk, our study indicates that these parameters should be monitored during hospitalization.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
Advanced oxidation processes (AOPs) have attracted special attention owing to the high removal efficiency of recalcitrant organic contaminants. Recently, the use of layered double hydroxides (LDHs) ...or LDH composites as catalysts for AOPs (photocatalysis, Fenton reaction methods, and sulfate radical (SO
4
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−
)-mediated oxidations) has received increasing attention and has become a new research hotspot. This is due to their layered structure, flexible tunability, electronic properties, and high physicochemical stability. Herein, we provide a comprehensive review on the development and progress in the synthesis of pristine LDH and modified LDH catalysts for AOPs. Special attention has been paid to the design strategies of high-performance LDHs, including (1) rational design of pristine LDHs, such as binary and ternary LDHs, (2) calcination of LDHs at an appropriate temperature, (3) modification of LDHs with a semiconductor or metal as a cocatalyst, (4) changing the compensating anions, and (5) controlling the LDH morphology. Finally, some valuable perspectives on the challenges and future research directions in LDH-based AOPs are discussed.
Various strategies to design LDH catalysts for advanced oxidation processes.
The integration of graphene nanosheets on the macroscopic level using a self‐assembly method has been recognized as one of the most effective strategies to realize the practical applications of ...graphene materials. Here, a facile and scalable method is developed to synthesis two types of graphene‐based networks, manganese dioxide (MnO2)–graphene foam and carbon nanotube (CNT)–graphene foam, by solution casting and subsequent electrochemical methods. Their practical applications in flexible all‐solid‐state asymmetric supercapacitors are explored. The proposed method facilitates the structural integration of graphene foam and the electroactive material and offers several advantages including simplicity, efficiency, low‐temperature, and low‐cost. The as‐prepared MnO2–graphene and CNT–graphene electrodes exhibit high specific capacitances and rate capability. By using polymer gel electrolytes, a flexible all‐solid‐state asymmetric supercapacitor was synthesized with MnO2–graphene foam as the positive electrode and CNT‐graphene as the negative electrode. The asymmetric supercapacitors can be cycled reversibly in a high‐voltage region of 0 to 1.8 V and exhibit high energy density, remarkable rate capability, reasonable cycling performance, and excellent flexibility.
Two types of graphene‐based networks, MnO2–graphene foam and carbon nanotube (CNT)–graphene foam, are designed and fabricated using a facile and scalable method. The asymmetric supercapacitor with the as‐obtained binder‐free MnO2–graphene foam as the positive electrode and the CNT–graphene foam as the negative electrode shows high energy density, reasonable cycling performance, and excellent flexibility.
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FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
The influences of different infrared drying conditions on drying kinetics, bioactive compounds and flavor of Cordyceps militaris were evaluated. The results indicated that as the drying temperature ...and air velocity increased, the total drying time and final water activity of Cordyceps militaris were reduced. Drying at 50, 60 and 70 °C reduced 30, 40 and 60% of the drying time compared to that of 40 °C, respectively. However, the glass transition temperature showed the opposite trend. Namely, a higher drying temperature favors the storage of dry products. Drying at 40 °C is beneficial to the retention of color and volatile compounds. For non-volatile flavor, relatively high drying temperature was more effective in reducing bitterness and bitter aftertaste. The best condition to retain the adenosine, cordycepin, total phenolics, and nutrients (Cu, Fe, Zn and Mn) in Cordyceps militaris is drying at a flow rate of 1 m s−1 at 60 °C.
•Drying at 50, 60 and 70 °C reduced 30, 40 and 60% of the drying time compared to that of 40 °C.•A higher drying temperature and air velocity favors the storage of the dried product.•Drying at 40 °C is beneficial to the retention of color quality index and volatile compounds.•The optimal condition to retain the bioactive components and nutrients is drying at 60 °C and 1 m s−1
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
DNA damage is the dominant source of mutation, which is the driving force of evolution. Therefore, it is important to quantitatively analyze the DNA damage caused by different mutagenesis methods, ...the subsequent mutation rates, and their relationship. Atmospheric and room temperature plasma (ARTP) mutagenesis has been used for the mutation breeding of more than 40 microorganisms. However, ARTP mutagenesis has not been quantitatively compared with conventional mutation methods. In this study, the umu test using a flow-cytometric analysis was developed to quantify the DNA damage in individual viable cells using Salmonella typhimurium NM2009 as the model strain and to determine the mutation rate. The newly developed method was used to evaluate four different mutagenesis systems: a new ARTP tool, ultraviolet radiation, 4-nitroquinoline-1-oxide (4-NQO), and N-methyl-N’-nitro-N-nitrosoguanidine (MNNG) mutagenesis. The mutation rate was proportional to the corresponding SOS response induced by DNA damage. ARTP caused greater DNA damage to individual living cells than the other conventional mutagenesis methods, and the mutation rate was also higher. By quantitatively comparing the DNA damage and consequent mutation rate after different types of mutagenesis, we have shown that ARTP is a potentially powerful mutagenesis tool with which to improve the characteristics of microbial cell factories.
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CEKLJ, DOBA, EMUNI, GEOZS, IJS, IMTLJ, IZUM, KILJ, KISLJ, MFDPS, NUK, OILJ, PILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UILJ, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
Severe COVID-19 disease caused by SARS-CoV-2 is frequently accompanied by dysfunction of the lungs and extrapulmonary organs. However, the organotropism of SARS-CoV-2 and the port of virus entry for ...systemic dissemination remain largely unknown. We profiled 26 COVID-19 autopsy cases from four cohorts in Wuhan, China, and determined the systemic distribution of SARS-CoV-2. SARS-CoV-2 was detected in the lungs and multiple extrapulmonary organs of critically ill COVID-19 patients up to 67 days after symptom onset. Based on organotropism and pathological features of the patients, COVID-19 was divided into viral intrapulmonary and systemic subtypes. In patients with systemic viral distribution, SARS-CoV-2 was detected in monocytes, macrophages, and vascular endothelia at blood-air barrier, blood-testis barrier, and filtration barrier. Critically ill patients with long disease duration showed decreased pulmonary cell proliferation, reduced viral RNA, and marked fibrosis in the lungs. Permanent SARS-CoV-2 presence and tissue injuries in the lungs and extrapulmonary organs suggest direct viral invasion as a mechanism of pathogenicity in critically ill patients. SARS-CoV-2 may hijack monocytes, macrophages, and vascular endothelia at physiological barriers as the ports of entry for systemic dissemination. Our study thus delineates systemic pathological features of SARS-CoV-2 infection, which sheds light on the development of novel COVID-19 treatment.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
BACKGROUND—There is a paucity of data from large cohort studies examining the prognostic significance of obstructive sleep apnea (OSA) in patients with coronary artery disease. We hypothesized that ...OSA predicts subsequent major adverse cardiac and cerebrovascular events (MACCEs) in patients undergoing percutaneous coronary intervention.
METHODS AND RESULTS—The Sleep and Stent Study was a prospective, multicenter registry of patients successfully treated with percutaneous coronary intervention in 5 countries. Between December 2011 and April 2014, 1748 eligible patients were prospectively enrolled. The 1311 patients who completed a sleep study within 7 days of percutaneous coronary intervention formed the cohort for this analysis. Drug-eluting stents were used in 80.1% and bioresorbable vascular scaffolds in 6.3% of the patients, and OSA, defined as an apnea-hypopnea index of ≥15 events per hour, was found in 45.3%. MACCEs, a composite of cardiovascular mortality, nonfatal myocardial infarction, nonfatal stroke, and unplanned revascularization, occurred in 141 patients during the median follow-up of 1.9 years (interquartile range, 0.8 years). The crude incidence of an MACCEs was higher in the OSA than the non-OSA group (3-year estimate, 18.9% versus 14.0%; p=0.001). Multivariate Cox regression analysis indicated that OSA was a predictor of MACCEs, with an adjusted hazard ratio of 1.57 (95% confidence interval, 1.10–2.24; P=0.013), independently of age, sex, ethnicity, body mass index, diabetes mellitus, and hypertension.
CONCLUSIONS—OSA is independently associated with subsequent MACCEs in patients undergoing percutaneous coronary intervention. Evaluation of therapeutic approaches to mitigate OSA-associated risk is warranted.
CLINICAL TRIAL REGISTRATION—URLhttp://www.clinicaltrials.gov. Unique identifierNCT01306526.
Fluoroalkylated enaminones, such as trifluridine and 5-trifluoromethyluracil, have widespread applications in pharmaceuticals and agrochemicals. Although these kinds of pharmaceutical agent often ...bear CF3 and perfluoroalkyl motifs in the core structure, access to such analogues typically requires multi-step synthesis. Here, we report a mild, metal-free and operationally simple strategy for the direct perfluoroalkylation of uracils, cytosines and pyridinones through a visible-light induced pathway from perfluoroalkyl iodides. This photochemical transformation features synthetic simplicity, mild reaction conditions without any photoredox catalyst, and high functional group tolerance, providing a facile route for applications in medicinal chemistry.
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