Molten salt construction of core-shell structured S-scheme CuInS_(2)@CoS_(2) heterojunction to boost charge transfer for efficient photocatalytic CO_(2) reduction

Weak redox ability and severe charge recombination pose significant obstacles to the advancement of CO_(2) photoreduction.To tackle this challenge and enhance the CO_(2) photoconversion efficiency,fabricating well-matched S-scheme heterostructure and establishing a robust built-in electric field emerge as pivotal strategies.In pursuit of this goal,a core-shell structured CuInS_(2)@CoS_(2)S-scheme heterojunction was meticulously engineered through a two-step molten salt method.This approach over the CuInS_(2)-based composites produced an internal electric field owing to the disparity be-tween the Fermi levels of CoS_(2) and CuInS_(2) at their interface.Consequently,the electric field facili-tated the directed migration of charges and the proficient separation of photoinduced carriers.The resulting CuInS_(2)@CoS_(2) heterostructure exhibited remarkable CO_(2) photoreduction performance,which was 21.7 and 26.5 times that of pure CuInS_(2) and CoS_(2),respectively.The S-scheme heterojunc-tion photogenerated charge transfer mechanism was validated through a series of rigorous anal-yses,including in situ irradiation X-ray photoelectron spectroscopy,work function calculations,and differential charge density examinations.Furthermore,in situ infrared spectroscopy and density functional theory calculations corroborated the fact that the CuInS_(2)@CoS_(2) heterojunction substan-tially lowered the formation energy of *COOH and *CO.This study demonstrates the application potential of S-scheme heterojunctions fabricated via the molten salt method in the realm of ad-dressing carbon-related environmental issues.

区域选择性地电化学氧化自由基参与的邻位-(4+2)/原位-(3+2)环化

碳环化合物,特别是五元环和六元环骨架,广泛存在于天然产物和生物活性分子中.Diels-Alder环加成反应是构建这些功能型分子的有效方法,但其底物适用范围有限,且反应条件(如热、微波和过渡金属的使用)苛刻,限制了该方法的应用.自由基物种含有不成对的价电子,表现出高活性,在温和的反应条件下提供了新的反应途径.因此,自由基介导的反应为复杂环状分子的合成提供了一个新平台.然而,如何实现选择性自由基环化仍然是一个挑战.鲍德温规则为自由基物种与烯烃炔烃的加成提供了指导,研究人员设计并开发了一系列反应模式构建所需的五元和六元环分子.但是,自由基物种,特别是烷基和烯基与芳基之间选择性的邻位原位环化仍然不明确.本文利用苄基丙二酸酯为自由基源,烯烃和炔烃分别为自由基受体,分别获得烷基和烯基自由基中间体,并探究烷基自由基和烯基自由基与芳基之间的选择性环化.利用二茂铁介导的电化学氧化策略,进行了烷基/烯基自由基与芳基的选择性环化实验.结果表明,烷基自由基与芳环发生选择性邻位-(4+2)环化,烯基自由基与芳环发生选择性原位-(3+2)环化.理论研究结果表明,促进烯烃优先邻位加成的主要原因是有利的相互作用能;炔烃优先原位加成区域选择性由形变能量控制.重要的是,该策略被认为是鲍德温自由基环化规则的重要补充.此外,对二茂铁介导的电化学氧化苄基丙二酸酯的C-H键官能团化进行了深入的机理研究.自由基捕获实验证明了苄基丙二酸酯碳自由基的存在.循环伏安测试结果表明,苄基丙二酸酯碳负离子与二茂铁之间存在电子转移.阳极电势实验证明了二茂铁在该自由基反应中的作用;同位素实验揭示了螺环化合物氧的来源.本文合成了一系列四氢萘和螺环衍生物,表现出较好的底物适用范围和官能团耐受性,且该方法避免了化学氧化剂/碱/贵金属的使用、底物的预官能团化以及底物的过氧化.综上,本文为实现自由基的区域选择性环化提供了参考.

Greenhouse gas emissions from Daihai Lake,China:Should eutrophication and salinity promote carbon emission dynamics?

Greenhouse gases(GHGs)emitted or absorbed by lakes are an important component of the global carbon cycle.However,few studies have focused on the GHG dynamics of eutrophic saline lakes,thus preventing a comprehensive understanding of the carbon cycle.Here,we conducted four sampling analyses using a floating chamber in Daihai Lake,a eutrophication saline lake in Inner Mongolia Autonomous Region,China,to explore its carbon dioxide(CO_(2))and methane(CH_(4))emissions.The mean CO_(2)emission flux(FCO_(2))and CH_(4)emission flux(FCH_(4))were 17.54±14.54 mmol/m^(2)/day and 0.50±0.50 mmol/m^(2)/day,respectively.The results indicated that Daihai Lake was a source of CO_(2)and CH_(4),and GHG emissions exhibited temporal variability.The mean CO_(2)partial pressure(p CO_(2))and CH_(4)partial pressure(p CH_(4))were 561.35±109.59μatm and 17.02±13.45μatm,which were supersaturated relative to the atmosphere.The regression and correlation analysis showed that the main influencing factors of p CO_(2)were wind speed,dissolved oxygen(DO),total nitrogen(TN)and Chlorophyll a(Chl.a),whereas the main influencing factors of p CH_(4)were water temperature(WT),Chl.a,nitrate nitrogen(NO_(3)^(-)-N),TN,dissolved organic carbon(DOC)and water depth.Salinity regulated carbon mineralization and organic matter decomposition,and it was an important influencing factor of p CO_(2)and p CH_(4).Additionally,the trophic level index(TLI)significantly increased p CH_(4).Our study elucidated that salinity and eutrophication play an important role in the dynamic changes of GHG emissions.However,research on eutrophic saline lakes needs to be strengthened.

功能性三尖瓣反流研究进展

功能性三尖瓣反流仍是巨大挑战,体现为术后三尖瓣反流复发率较高。术前判定三尖瓣病变程度指标有三尖瓣反流量、右室和三尖瓣环扩张程度、三尖瓣瓣叶病理改变。三尖瓣成形术主要包括对瓣膜、瓣环、瓣下结构三部分处理。近年主张对三尖瓣反流进行更积极干预。

Regulation of FN1 degradation by the p62/SQSTM1-dependent autophagy-lysosome pathway in HNSCC

Epithelial–mesenchymal transition(EMT)is involved in both physiological and pathological processes.EMT plays an essential role in the invasion,migration and metastasis of tumours.Autophagy has been shown to regulate EMT in a variety of cancers but not in head and neck squamous cell carcinoma(HNSCC).Herein,we investigated whether autophagy also regulates EMT in HNSCC.Analyses of clinical data from three public databases revealed that higher expression of fibronectin-1(FN1)correlated with poorer prognosis and higher tumour pathological grade in HNSCC.Data from SCC-25 cells demonstrated that rapamycin and Earle’s balanced salt solution(EBSS)promoted autophagy,leading to increased FN1 degradation,while 3-methyladenine(3-MA),bafilomycin A1(Baf A1)and chloroquine(CQ)inhibited autophagy,leading to decreased FN1 degradation.On the other hand,autophagic flux was blocked in BECN1 mutant HNSCC Cal-27 cells,and rapamycin did not promote autophagy in Cal-27 cells;also in addition,FN1 degradation was inhibited.Further,we identified FN1 degradation through the lysosome-dependent degradation pathway using the proteasome inhibitor MG132.Data from immunoprecipitation assays also showed that p62/SQSTM1 participated as an autophagy adapter in the autophagy–lysosome pathway of FN1 degradation.Finally,data from immunoprecipitation assays demonstrated that the interaction between p62 and FN1 was abolished in p62 mutant MCF-7 and A2780 cell lines.These results indicate that autophagy significantly promotes the degradation of FN1.Collectively,our findings clearly suggest that FN1,as a marker of EMT,has adverse effects on HNSCC and elucidate the autophagy–lysosome degradation mechanism of FN1.

Unified Principal S-N Equation for Friction Stir Welding of 5083 and 6061 Aluminum Alloys

With the popularization of friction stir welding(FSW),5083-H321 and 6061-T6 aluminum alloy materials are widely used during the FSW process.In this study,the fatigue life of friction stir welding with two materials,i.e.,5083-H321 and 6061-T6 aluminum alloy,are studied.Fatigue tests were carried out on the base metal of these two materials as well as on the butt joints and overlapping FSW samples.The principle of the equivalent structural stress method is used to analyze the FSW test data of these two materials.The fatigue resistances of these two materials were com-pared and a unified principal S-N curve equation was fitted.Two key parameters of the unified principal S-N curve obtained by fitting,Cd is 4222.5,and h is 0.2693.A new method for an FSW fatigue life assessment was developed in this study and can be used to calculate the fatigue life of different welding forms with a single S-N curve.Two main fatigue tests of bending and tension were used to verify the unified principal S-N curve equation.The results show that the fatigue life calculated by the unified mean 50%master S-N curve parameters are the closest to the fatigue test results.The reliability,practicability,and generality of the master S-N curve fitting parameters were verified using the test data.The unified principal S-N curve acquired in this study can not only be used in aluminum alloy materials but can also be applied to other materials.

高含钙钡离子的油田采出水结垢规律研究

通过对2种油田采出水在不同温度、pH值下进行配伍试验，研究了配伍条件对总结垢量、CaCO3结垢、BaSO4结垢的影响。研究发现，25℃的结垢趋势偏向于BaSO4主导，60℃的结垢趋势偏向于CaCO3主导。提高温度、pH值都会促使总结垢量增加，60℃组结垢量比25℃组大约增加20％，增加量的主要贡献是CaCO3结垢。BaSO4结垢较完全，受温度、pH值影响较小，而温度、pH值对CaCO3结垢增加影响大；pH值对结垢产生非常重要的影响，pH值上升使碳酸盐结垢量成倍增加，当pH值上升到10．2以上时，导致Mg（OH）2结垢生成。

Polycation-functionalized gold nanodots with tunable near-infrared fluorescence for simultaneous gene delivery and cell imaging

Near-infrared （NIR） fluorescent metal nanodots may have significant advantages in biological detection and bioimaging. Herein, we introduce tunable near-infrared fluorescent gold nanodots （AuNDs） protected by branched polyethylenimine （PEI） modified by surface segmental attachment of sulfhydryl groups （PEI-SH）, abbreviated as PEI-SH-AuNDs, for simultaneous gene delivery and cell imaging. The modified PEI endows the resultant PEI-SH-AuNDs with the following excellent advantages. Sulfhydryl groups of PEI-SH anchor to the surface of AuNDs, and such polycations with amine groups give PEI-SH-AuNDs remarkable stability. The cationic polymer PEI-SH with positive charges enables PEI-SH-AuNDs to perform gene delivery, and the gene transfection efficiency can reach 22.8%. Moreover, the fluorescence of PEI-SH-AuNDs is tunable from visible red light （wavelength 609 nm） to NIR light （wavelength 811 run） via an increase in the size of AuNDs. PEI-SH-AuNDs yielded gene transfection efficiency similar to that of commercial PEI, but showed much lower cytotoxicity and much greater red-shift fluorescence. With excellent photoluminescent properties, such multifunctional fluorescent PEI-SH-AuNDs hold promise in applications to bioimaging and as ideal fluorescent probes for tracking gene transfection behavior.

Testing of tuberculosis infection among Chinese adolescents born after terminating the Bacillus Calmette-Guerin booster vaccination： subgroup analysis of a population-based cross-sectional study

The prevalence of tuberculosis infection among adolescents born after terminating the Bacillus Calmette-Guerin （BCG） booster vaccination in China was estimated using tuberculin skin testing （TST） and QuantiFERON-TB Gold assay （QFT） to investigate the influence of neonatal BCG vaccination on the performance of TST. Data analysis was conducted for 2831 eligible participants aged 5-15 years from the baseline survey of a population-based multi-center prospective study. The prevalence rates of TST （induration ≥ 10 mm） and QFT positivity were 9.3% （264/2827） and 2.5% （71/2831）, respectively. The rate of QFT indeterminate result was 2.2% （62/2831）. The overall agreement between TST and QFT was low （concordance = 88.0%; K coefficient = 0.125）. Only TST was positively associated with BCG vaccination with an adjusted odds ratio of 1.71 [95% confidence interval, 1.26-2.31 ]. A history of close contact with patients of active TB was significantly associated with positivity for TST and QFT. Our results suggested that BCG neonatal vaccination still affects TST performance, and a two- step approach might be considered for TB infection testing among adolescents in China.

Effects of porous clay ceramic rates on aeration porosity characteristics in a structurally degraded soil under greenhouse vegetable production

Soil structure degradation in greenhouse vegetable fields reduces vegetable production. Increasing aeration porosity is the key to ameliorating soil structure degradation. Thus, we tested the effect of a porous material, porous clay ceramic(PLC), on the amelioration of soil structure degradation under greenhouse vegetable production. A 6-month pot experiment was conducted with four PLC application levels based on volume, i.e., 0%(control), 5%(1 P), 10%(2 P), and15%(3 P) using Brassica chinensis as the test plant. At the end of the experiment, soil columns were sampled, and the aeration pore network was reconstructed using X-ray computed tomography(CT). The degree of anisotropy(DA), fractal dimension(FD), connectivity, aeration porosity, pores distribution, and shape of soil aeration pores and plant biomass were determined. The DA, FD, and connectivity did not significantly differ as the PLC application rate increased.Nonetheless, aeration porosity significantly linearly increased. The efficiency of PLC at enhancing soil aeration porosity was 0.18% per Mg ha^(-1). The increase in aeration porosity was mainly due to the increase in pores > 2 000 μm, which was characterized by irregular pores. Changes in aeration porosity enhanced the production of B. chinensis. The efficiency of PLC at increasing the plant fresh weight was 0.60%, 3.06%, and 2.12% per 1% application rate of PLC for the 1 P, 2 P, and 3 P treatments, respectively. These results indicated that PLC is a highly efficient soil amendment that improves soil structure degradation by improving soil aeration under greenhouse conditions. Based on vegetable biomass, a 10% application rate of PLC was recommended.

Treatment outcomes of pulmonary tuberculosis in the past decade in the mainland of China:a meta-analysis

Due to the implementation of directly observed treatment strategy(DOTS),China has made a significant achievement in tackling the tuberculosis(TB)epidemic in the 1990s.However,only half of regions in China met or exceeded the 85%rate of treatment success target.The aim of the present study is to summarize the treatment outcomes of smear-positive pulmonary TB in the mainland of China in the past decade using meta-analysis based on systematic review of published observational studies.A total of 50 eligible articles(58 studies)were identified and included in this study.The summarized treatment success rates were 93.9%(95%CI,92.8%–94.7%)for new cases and 85.4%(95%CI,83.0%–87.6%)for previously treated cases,and the summarized cured rate were 92.2%(95%CI,90.9%–93.3%)and 81.2%(95%CI,79.1%–83.1%),respectively.A remarkable increase of rates for treatment success and cure was observed in the 1990s.After 2000,the summarized treatment outcomes were tending towards stability.In addition,geographic areas,type of the data and administrative level of the hospital were also found to influence the estimates of the treatment outcomes.Results of the present study clearly show,in general,that the pulmonary TB treatment achieved significant success in the past decade in the mainland of China.However,it needs to be further strengthened in the central and west areas.

Geographically driven shifts in land use influence phytoplankton community patterns in the Inner Mongolian Plateau lakes

Phytoplankton play an irreplaceable role as producers in maintaining lake ecosystems.Nevertheless,scant attention has been given to investigating the dispersion of phytoplankton communities and the factors influencing them across expansive areas.In this study,we present the results of a survey on the distribution of phytoplankton community and the effects of different driving factors in 11 lakes along Inner Mongolia in July–August 2020.Non-metric multidimensional scaling analysis and variance decomposition(VPA)were used to elucidate the distribution of phytoplankton communities and the response of drivers.A total of 169 species of phytoplankton from 8 phyla were detected.Both the abundance and diversity of phytoplankton in the Inner Mongolia lakes showed a trend of high in the east and low in the west(with Daihai Lake as the boundary).The Margalef index of phytoplankton significantly negatively correlated with salinity(r=−0.707,P<0.05)and total dissolved solids(r=−0.720,P<0.05),and both density and biomass highly significantly positively correlated with the suspended solids,Chlorophyll a and trophic level index.The VPA explained 38.9%of the changes in the phytoplankton community with the highest rate of explanation of land use.Therefore,preventing anthropogenic impacts,as well as reducing nutrient loads,can effectively ensure the ecological diversity of lake phytoplankton in lake populations with large geographical spans and varying levels of nutrients.