Strong interactions in molybdenum disulfide heterostructures boosting the catalytic performance of water splitting: A short review

Two-dimensional materials(2DMs) have attracted substantial attention due to their abundant active sites and their ultrahigh surface area for different catalytic applications due to the high lateral-longitudinal ratio. Transition metal dichalcogenides(TMDs), especially MoS2, as one of the 2DMs most often studied, have shown superior activity in electrochemical applications. Recently, combinations of different 2DMs have been widely studied, and they appear to be the most promising strategy available to develop state of the art catalysts for different reactions.In this article, we review the interactions between MoS2 and other materials as well as the novel assembly induced phase transitions of TMDs and their underlying mechanisms. Several methods for inducing the phase transition of TMDs by building MoS2-based heterostructures have been introduced. The electronic coupling between these counterparts has significantly enhanced their conductivity and optimized the energy states of the materials, thus introducing enhanced activity as compared to their original counterparts. The ideas summarized in this article may shed new light on and help to develop next-generation green energy materials by designing and constructing highly active two-dimensional catalysts for efficient water splitting.

Cascade electrocatalytic reduction of carbon dioxide and nitrate to ethylamine

CO_(2) utilization,including electrochemical reduction of CO_(2) to fuels and useful chemicals,is explored to valorize carbon emissions[1–12].The value of CO_(2) electroreduction products originates from their C–H,C–C,and C–O bonds.To further increase the value and expand the scope of products,it is desirable to integrate C–N bond formation with the electrochemical reduction of CO_(2).

Large variability in ambient ozone sensitivity across 19 ethylenediurea-treated Chinese cultivars of soybean is driven by total ascorbate

The sensitivity of Chinese soybean cultivars to ambient ozone（O3） in the field is unknown,although soybean is a major staple food in China. Using ethylenediurea（EDU） as an O3 protectant, we tested the gas exchange, pigments, antioxidants and biomass of 19 cultivars exposed to 28 ppm·hr AOT40（accumulated O3 over an hourly concentration threshold of40 ppb） over the growing season at a field site in China. By comparing the average biomass with and without EDU, we estimated the cultivar-specific sensitivity to O3 and ranked the cultivars from very tolerant（〈 10% change） to highly sensitive（〉 45% change）, which helps in choosing the best-suited cultivars for local cultivation. Higher lipid peroxidation and activity of the ascorbate peroxidase enzyme were major responses to O3 damage, which eventually translated into lower biomass production. The constitutional level of total ascorbate in the leaves was the most important parameter explaining O3 sensitivity among these cultivars. Surprisingly, the role of stomatal conductance was insignificant. These results will guide future breeding efforts towards more O3-tolerant cultivars in China, while strategies for implementing control measures of regional O3 pollution are being implemented. Overall, these results suggest that present ambient O3 pollution is a serious concern for soybean in China, which highlights the urgent need for policy-making actions to protect this critical staple food.

Tetrahydrobiopterin Protects against Radiation-induced Growth Inhibition in H9c2 Cardiomyocytes

Background：Tetrahydrobiopterin （BH4） is an essential cofactor of nitric oxide synthases （NOSs） for the synthesis of nitric oxide （NO）.BH4 therapy can reverse the disease-related redox disequilibrium observed with BH4 deficiency.However,whether BH4 exerts a protective effect against radiation-induced damage to cardiomyocytes remains unknown.Methods：Clonogenic assays were performed to determine the effects of X-ray on H9c2 cells with or without BH4 treatment.The contents of lactate dehydrogenase （LDH）,superoxide dismutase （SOD）,and malondialdehyde （MDA） in H9c2 cells were measured to investigate oxidative stress levels.The cell cycle undergoing radiation with or without BH4 treatment was detected using flow cytometry.The expression levels of proteins in the phosphatidylinositol 3 kinase （PI3K）/protein kinase B （AKT）/P53 signaling pathway,inducible NOS （iNOS）,and endothelial NOS （eNOS） were examined using Western blotting.Results：X-ray radiation significantly inhibited the growth of H9c2 cells in a dose-dependent manner,whereas BH4 treatment significantly reduced the X-ray radiation-induced growth inhibition （control group vs.X-ray groups,respectively,P 〈 0.0 l）.X-ray radiation induced LDH release,apoptosis,and G0/G 1 peak accumulation,significantly increasing the level of MDA and the production of NO,and decreased the level of SOD （control group vs.X-ray groups,respectively,P 〈 0.05 or P 〈 0.01）.By contrast,BH4 treatment can significantly reverse these processes （BH4 treatment groups vs.X-ray groups,P 〈 0.05 or P 〈 0.01）.BH4 reversed the X-ray radiation-induced expression alterations ofapoptosis-related molecules,including B-cell lymphoma-2 （Bcl-2）,Bcl-2 associated X protein,and caspase-3,and molecules of the PI3K/Akt/P53 signaling pathway.BH4 enhanced the production of NO in 2 Gy and 4 Gy radiated groups by upregulating eNOS protein expression and downregulating iNOS protein expression.Conclusions：BH4 treatment can protect against X-ray-induced cardiomyocyte injury,possibly by recoupling eNOS rather than iNOS.BH4 treatment also decreased oxidative stress in radiated H9c2 cells.

A Human Active Lower Limb Model for Chinese Pedestrian Safety Evaluation

A subsystem impactor test for pedestrian lower limb injury evaluation has been brought in China New Car Assessment Protocol(CNCAP).Concerning large anthropometric differences of the people from different countries,the present study aims to establish and validate a finite element lower limb model representing 50th Chinese male size for pedestrian safety research,then compare its biomechanical responses with the general models currently in wide use in the world for pedestrian safety evaluation.Concerning the vehicle-pedestrian impact loading environment,the previously developed lower limb model with three-dimensional muscles was adjusted and validated through the related experiments.Then,the biomechanical responses of the validated model were compared with the Total Human Model for Safety(THUMS)and Advanced Pedestrian Legform Impactor(aPLI)models by combing with four typical vehicles.The results showed that both consistency and significant differences of biomechanical responses existed between the present model and the other two models.The injury measurements of the thigh region of the present model showed extremely large differences with the other two models,while the tibia and Medial Collateral Ligament(MCL)injury measurements show similar values.Thus,it can be concluded that directly using the aPLI or THUMS models for Chinese pedestrian safety evaluation is not robust concerning both kinematic responses and injury measurements.

Protective humoral immunity in SARS-CoV-2 infected pediatric patients

After the rapid spread of SARS-CoV-2 in Wuhan,China,at the beginning of 2020,about 1.5 million confirmed cases and over 80,000 deaths have been reported around 200 countries and territories all over the world and the number continues to increase.However,we still have limited knowledge of this new coronavirus,especially the interaction between SARS-CoV-2 and our immune system.

臭氧和氮添加对杨树叶片氮代谢的影响

臭氧(O_(3))污染和氮(N)沉降/施肥都能同时影响植物的生长。然而,几乎没有研究探究O_(3)和\添加对植物叶片N代谢过程的复合影响。本研究在开顶式气室(OTC)中对杨树进行了为期95d的熏蒸实验,包括两个O_(3)水平(NF,环境O_(3)水平;NF60,NF+60 ppb O_(3))和4个N处理(N0,没有N添加;N50,N0+50 kg N ha^(-1)yr^(-1);N100,NO+100 kg N ha^(-1)yr^(-1):N200,NO+200 kg N ha^(-1)yr^(-1))。测定了与叶片N代谢相关的一些指标,包括叶片N代谢酶的活性、总叶片N浓度、NO_(3)^(-)-N浓度、NH_(4)^(+)-N浓度、总氨基酸浓度(TAA)、总可溶性糖的浓度(TSP)。研究结果表明,相对于NF,在8月份NF60处理显著刺激了硝酸还原酶(NR)的活性,使其升高了47.2%。当平均所有的N处理和两次取样时间时,NF60处理下谷氨酰胺酶(GS)的活性比NF处理下的高57.3%。但是O_(3)处理并没有显著影响TSP浓度,并且在8月降低了TAA的浓度。相对NO,高的N添加处理(N200)显著增加了杨树叶片的饱和光合速率(Asat)24%,并且分别在8和9月增加了总叶片N浓度70.3%和43.3%。但是在8月份,N200处理下光合N利用效率比NO的低26.1%。这表明N添加导致的Asat和叶片总的N浓度的升高是不匹配的,高N处理下,叶片中一些剩余的N没有被用于优化植物碳的同化。同时,也发现高N添加显著刺激了叶片N代谢过程,叶片中的NO_(3)^(-)-N浓度、NH_(4)^(-)-N浓度、TAA浓度、NR和GS活性都显著升高。然而,O_(3)和N添加对杨树叶片所有N代谢相关的指标都没有交互影响。这些结果将有助于更好地了解在高O_(3)污染和N沉降/施肥下植物的N代谢过程以及生物地球化学循环过程。

Water-soluble PANI:PSS designed for spontaneous non-disruptive membrane penetration and direct intracellular photothermal damage on bacteria

The major challenge in the field of antibacterial agents is to overcome the low-permeability of bacteria cell membranes that protects the cells against diverse drugs.In this work,water-soluble polyaniline(PANI)-poly(p-styrenesulfonic acid)(PSS)(PANI:PSS)is found to spontaneously penetrate bacteria cellular membranes in a non-disruptive way,leaving no evidence of membrane poration/disturbance or cell death,thus avoiding side effects caused by cationic ammonia groups in traditional ammonia-containing antibacterial agents.For aqueous synthesis,which is important for biocompatibility,the polymer is synthesized via an enzyme-mimetic route relying on the catalysis of a nanozyme.Owing to its fluorescent properties,the localization of as-prepared PANI:PSS is determined by the confocal microscope,and the results confirm its rapid entry into bacteria.Under 808 nm near-infrared(NIR)irradiation,the internalized PANI:PSS generates local hyperthermia and destroys bacteria highly efficiently from inside the cells due to its excellent photothermal effects.Staphylococcus aureus(S.aureus),Methicillin-resistant Staphylococcus aureus(MRSA)and Escherichia coli(E.coli)could be effectively eliminated as well as the corresponding bacterial biofilms.Results of in vivo antibacterial experiments demonstrate excellent antibacterial activities of the water-soluble PANI:PSS without side effects.Therefore,the prepared water-soluble polymer in this study has great potential in the treatment of various bacterial infections.