Carbon fiber confined mixed Ni-based crystal phases with interfacial charge redistribution induced by high bond polarity for electrochemical urea-assisted hydrogen generation

Interfacial electronic structure modulation of nickel-based electrocata-lysts is significant in boosting energy-conversion-relevant urea oxidation reaction(UOR).Herein,porous carbon nanofibers confined mixed Ni-based crystal phases of Ni_(2)P and NiF_(2) are developed via fluorination and phosphorization of Ni coated carbon nanofiber(Ni_(2)P/NiF_(2)/PCNF),which possess sufficient mesoporous and optimized Gibbs adsorption free energy by mixed phase-induced charge redistribution.This novel system further reduces the reaction energy barrier and improves the reaction activity by addressing the challenges of low intrinsic activity,difficulty in active site formation,and insufficient synergism.A considerably high current density of 254.29 mA cm^(-2) is reached at 1.54 V versus reversible hydrogen electrode on a glass carbon electrode,and the cell voltage requires 1.39 V to get 10 mA cm^(-2) in hydrogen generation,with very good stability,about 190 mV less than that of the traditional water electrolysis.The facile active phase formation and high charge transfer ability induced by asymmetric charge redistribution are found in the interface,where the urea molecules tend to bond with Ni atoms on the surface of heterojunction,and the rate-determining step is changed from CO_(2) desorption to the fourth H-atom deprotonation.The work reveals a novel catalyst system by interfacial charge redistribution induced by high bond polarity for energy-relevant catalysis reactions.

The Effect of Blood Lipid Profiles on Chronic Kidney Disease in a Prospective Cohort:Based on a Regression Discontinuity Design

Objective Previous studies on the association between lipid profiles and chronic kidney disease(CKD)have yielded inconsistent results and no defined thresholds for blood lipids.Methods A prospective cohort study including 32,351 subjects who completed baseline and follow-up surveys over 5 years was conducted.Restricted cubic splines and Cox models were used to examine the association between the lipid profiles and CKD.A regression discontinuity design was used to determine the cutoff value of lipid profiles that was significantly associated with increased the risk of CKD.Results Over a median follow-up time of 2.2(0.5,4.2)years,648(2.00%)subjects developed CKD.The lipid profiles that were significantly and linearly related to CKD included total cholesterol(TC),triglycerides(TG),high-density lipoprotein cholesterol(HDL-C),TC/HDL-C,and TG/HDL-C,whereas lowdensity lipoprotein cholesterol(LDL-C)and LDL-C/HDL-C were nonlinearly correlated with CKD.TC,TG,TC/HDL-C,and TG/HDL-C showed an upward jump at the cutoff value,increasing the risk of CKD by 0.90%,1.50%,2.30%,and 1.60%,respectively,whereas HDL-C showed a downward jump at the cutoff value,reducing this risk by 1.0%.Female and participants with dyslipidemia had a higher risk of CKD,while the cutoff values for the different characteristics of the population were different.Conclusion There was a significant association between lipid profiles and CKD in a prospective cohort from Northwest China,while TG,TC/HDL-C,and TG/HDL-C showed a stronger risk association.The specific cutoff values of lipid profiles may provide a clinical reference for screening or diagnosing CKD risk.

藏东南大气中多环芳烃的污染特征及来源分析

为探究青藏高原东南部大气中多环芳烃(Polycyclic Aromatic Hydrocarbons,简称PAHs)的污染、源及输送特征,利用鲁朗地区(29.77°N,94.73°E)总悬浮颗粒物(Total Suspended Particles,简称TSP)和大气中的14种PAHs含量,结合同期气象环境数据进行了综合分析。结果表明,该地区TSP中PAHs和气相的PAHs质量浓度变化范围分别为0.22~5.05 ng m^(-3)和0.83~63.75 ng m^(-3),平均值分别为2.13 ng m^(-3)和11.33 ng m^(-3)。薪柴和柴油的燃烧是污染的主要方式,汽油燃烧等其他排放为次要方式。PAHs来自本地污染和远距离传输(Long Range Transmission,简称LRT)共同的影响。本地污染在四季各个源地均不相同。冬春季本地污染大,源在东南及正南方,夏秋季受本地和外来输送共同作用,本地源在东南方且占比小,LRT占比大。LRT受西北气流、西风气流和西南气流三支气流影响,污染严重时西南气流占主导,西风气流次之,污染较轻时西风气流或西北气流占主导,西北气流所传输的污染最少。该研究结果加深了对藏东南区域PAHs变化、输送特征的认识,为该区域大气污染治理提供了理论依据。

异质结构NiSe_(2)/MoSe_(2)用于高效尿素辅助电解水制氢

电催化水分解是实现绿色制氢的理想方法之一.然而,阳极析氧反应(OER)固有的缓慢动力学和高理论电压(1.23V),使得电解水制氢的能效受到严重限制.采用理论电位更低和热力学更有利的小分子氧化反应替代OER过程,可以在降低电能耗的同时降解污染物或生成有附加值的产物,能够带来多重效益.尿素氧化反应(UOR)具有较低的理论电压(0.37V),是替代OER的潜在反应之一.然而,UOR中复杂的六电子转移严重阻碍了尿素电解的整体效率.因此,设计经济且高效的电催化剂来促进UOR固有的缓慢动力学过程非常必要.硒化镍具有电子构型多样和结构调控灵活等优点,被认为是有效的UOR催化剂.然而,UOR过程涉及催化剂表面多种反应中间体的吸附/解吸,单相催化剂要同时满足多种反应中间的吸附/解吸是一项艰巨的挑战.众所周知,非均相电催化涉及电子转移以及电催化剂表面反应物和产物的吸附和解吸.因此,催化剂的电催化性能在很大程度上取决于材料表面的电子特性.通过构建异质结构是一种有效策略,可以调节电催化剂的电子结构,优化反应中间体的化学吸附行为,实现不同组份高效协同电催化.研究表明,通过界面工程优化结构和电子特性可进一步促进UOR的动力学.MoSe_(2)具有良好的稳定性和导电性,与镍基催化剂组合构建异质结构能够改善电催化反应中的催化动力学.本文通过简单的水热和低温硒化方法构建了异质NiSe_(2)/MoSe_(2)微球作为UOR的电催化剂.差分电荷密度和Mulliken电荷分析结果表明,MoSe_(2)与NiSe_(2)的耦合引起界面处的电荷重新分布,促使电子从NiSe_(2)向MoSe_(2)转移,更容易形成高价态Ni(NiOOH)活性物种.另外,异质界面的构建优化了催化剂表面的电子结构并调节d带中心,改变反应途径,降低反应能垒,从而提高UOR的反应活性.异质结NiSe_(2)/MoSe_(2)微球由于其独特的结构特征、强的协同耦合作用、增加的活性中心和高含量的高价Ni3+物种的综合优势而具有高效的催化性能.当负载在玻碳电极上时,仅需1.33 V的电压就能驱动10 m Acm^(-2)的电流密度,该活性优于大多数已报道的非贵金属UOR催化剂.将NiSe_(2)/MoSe_(2)催化剂组装到UOR//HER电解槽中时,NiSe_(2)/MoSe_(2)|Pt/C具有较低的操作电压和长期稳定性,在1.47 V的电池电压下电流密度达到10 m Acm^(-2),比单纯的水电解降低了约220 m V.与OER相比,热力学上有利的UOR可以作为阳极OER替代反应.综上,本文为能源/环境相关的催化反应提供了一个有效的催化剂体系,对构建高效异质结催化系统具有借鉴意义.

Predictive value of total cholesterol to high-density lipoprotein cholesterol ratio for chronic kidney disease among adult male and female in Northwest China

Background: Studies have found that the ratio of total cholesterol to high-density lipoprotein cholesterol (TC/HDL-C) was associated with the development of chronic kidney disease (CKD). However, the relationship in different genders was rarely discussed. The aim of this study was to explore this relationship and assess its predictive power for both males and females.Methods: Based on a prospective cohort platform in northwest China, 32,351 participants without CKD were collected in the baseline and followed up for approximately 5 years. Cox proportional hazard model and restricted cubic spline regression analysis were performed to investigate the association between TC, HDL-C, TC/HDL-C and CKD in adult female and male. The clinical application value of the indicators in predicting CKD was evaluated by the receiver operator characteristic curve.Results: During a mean follow-up of 2.2 years, 484 males and 164 females developed CKD. After adjusted for relevant confounders, for every one standard deviation increase in TC, HDL-C and TC/HDL-C, the hazard ratios (HRs) and 95% confidence intervals (95% CIs) for CKD were 1.17 (1.05-1.31), 0.84 (0.71-0.99), and 1.15 (1.06-1.25) for males, 0.94 (0.78-1.13), 0.58 (0.35-0.95), and 1.19 (1.01-1.40) for females, respectively. The results also showed that TC, HDL-C, and TC/HDL-C were associated with CKD in a linear dose-response relationship. The TC/HDL-C had the largest area under the curve (AUC) compared to TC and HDL-C, and the AUC among the females was larger than that among males.Conclusions: The TC/HDL-C was significantly associated with CKD in adult males and females and has better clinical value in predicting CKD than TC and HDL-C, especially in females.

Comparing the Diagnostic Criteria of MAFLD and NAFLD in the Chinese Population:A Population-based Prospective Cohort Study

Background and Aims:Metabolic dysfunction-associ-ated fatty liver disease(MAFLD)is a new concept,pro-posed in 2020;however,its applicability in Asia populations has yet to be evaluated.Therefore,we aimed to compare the difference in epidemiological and clinical characteris-tics between MAFLD and non-alcoholic fatty liver disease(NAFLD)among Asian populations.Methods:Based on the Jinchang cohort,30,633 participants were collected.The prevalence and incidence of MAFLD and NAFLD were used to analyze the epidemic characteristics and its overlapping effects.In addition,the corresponding clinical character-istics of the two diagnostic criteria populations were com-pared.Results:The prevalence rates of MAFLD and NAFLD were 21.03%and 18.83%,respectively.After an average 2.28-year follow-up,the incidence densities of MAFLD and NAFLD were 41.58 per 1,000 person-years and 37.69 per 1,000 person-years,respectively.With the increase of baseline age,body mass index(BMI),and waist circumfer-ence(WC)levels,the prevalence and incidence of MAFLD and NAFLD were on the rise(all ptrend<0.05).Among the total patients diagnosed at baseline or follow-up,most pa-tients had both MAFLD and NAFLD,accounting for 78.84%and 82.88%,respectively.Compared with NAFLD,MAFLD patients had greater proportions of males and metabolic diseases(diabetes,dyslipidemia),and had higher BMI,WC,liver enzymes,blood glucose,and lipid levels in the base-line diagnosis patients(p<0.05).Additionally,lean MAFLD patients had higher metabolic disorders than lean NAFLD patients(p<0.05).Conclusions:Compared with NAFLD,the newly proposed definition of MAFLD is more practical and accurate,and it can help identify more fatty liver pa-tients with high-risk diseases.

Polyoxypregnanes as safe, potent, and specific ABCB1-inhibitory pro-drugs to overcome multidrug resistance in cancer chemotherapy in vitro and in vivo

Multidrug resistance(MDR)mediated by ATP binding cassette subfamily B member 1(ABCB1)is significantly hindering effective cancer chemotherapy.However,currently,no ABCB1-inhibitory drugs have been approved to treat MDR cancer clinically,mainly due to the inhibitor specificity,toxicity,and drug interactions.Here,we reported that three polyoxypregnanes(POPs)as the most abundant constituents of Marsdenia tenacissima(M.tenacissima)were novel ABCB1-modulatory pro-drugs,which underwent intestinal microbiota-mediated biotransformation in vivo to generate active metabolites.The metabolites at non-toxic concentrations restored chemosensitivity in ABCB1-overexpressing cancer cells via inhibiting ABCB1 efflux activity without changing ABCB1 protein expression,which were further identified as specific non-competitive inhibitors of ABCB1 showing multiple binding sites within ABCB1 drug cavity.These POPs did not exhibit ABCB1/drug metabolizing enzymes interplay,and their repeated administration generated predictable pharmacokinetic interaction with paclitaxel without obvious toxicity in vivo.We further showed that these POPs enhanced the accumulation of paclitaxel in tumors and overcame ABCB1-mediated chemoresistance.The results suggested that these POPs had the potential to be developed as safe,potent,and specific pro-drugs to reverse ABCB1-mediated MDR.Our work also provided scientific evidence for the use of M.tenacissima in combinational chemotherapy.

Spacecraft damage infrared detection algorithm for hypervelocity impact based on double-layer multi-target segmentation

To detect spacecraft damage caused by hypervelocity impact,we propose an advanced spacecraft defect extraction algorithm based on infrared imaging detection.The Gaussian mixture model(GMM)is used to classify the temperature change characteristics in the sampled data of the infrared video stream and reconstruct the image to obtain the infrared reconstructed image(IRRI)reflecting the defect characteristics.The designed segmentation objective function is used to ensure the effectiveness of image segmentation results for noise removal and detail preservation,while taking into account the complexity of IRRI(that is,the required trade-offs are different).A multi-objective optimization algorithm is introduced to achieve balance between detail preservation and noise removal,and a multi-objective evolutionary algorithm based on decomposition(MOEA/D)is used for optimization to ensure damage segmentation accuracy.Experimental results verify the effectiveness of the proposed algorithm.

高原心血管疾病的防治及相关标志物研究进展

目的综述高原心血管疾病的防治及相关标志物研究进展。资料来源与选择国内外该领域的相关文献。资料引用以"高原""心血管疾病"等为关键词,从PubMed、维普、中国知网、万方医学网等相关数据库遴选近年来相关文献63篇。资料综合肺动脉高压、长期缺氧为部分常见高原疾病的发生发展机制。高原心血管疾病常见的预防和治疗策略包括早期筛查、缓解缺氧、治疗水肿。基因、血清和影像是高原心血管疾病预防、诊断和治疗的标志物。结论研究高原心血管疾病的发生发展机制、相关标志物和防治策略,对推进该疾病防治的理论研究和实际应用,降低其发病率和死亡率具有重要意义。

Artificial intelligence in impact damage evaluation of space debris for spacecraft

Since the first artificial satellite was launched in 1957,increasing human space activities have led to a deteriorating space debris environment.A huge amount of tiny space debris(from millimeter to micron level)appears in the Earth’s orbit,and its hypervelocity impact will cause serious damage to the structure and functional units of the spacecraft,including cabin’s outer surface,thermal barrier materials,thermal con-trol coatings,solar panels,pipes,and cables.To ensure the safe operation of spacecraft and the completion of space missions.