The application of electrocatalysts for the oxygen reduction reaction(ORR) is vital in a variety of energy conversion technologies. Exploring low-cost ORR catalysts with high activity and long-term stability is highly...The application of electrocatalysts for the oxygen reduction reaction(ORR) is vital in a variety of energy conversion technologies. Exploring low-cost ORR catalysts with high activity and long-term stability is highly desirable, although it still remains challenging. Herein, we report a facile and reliable route to convert ZIF-8 modified by Fe-phenanthroline into Fe-incorporated and N-doped carbon dodecahedron nanoarchitecture(Fe-NCDNA), in which carbon nanosheets are formed in situ as the building blocks with uniform Fe-N-C species decoration. Systematic electrochemical studies demonstrate that the as-synthesized Fe-NCDNA electrocatalyst possesses highly attractive catalytic features toward the ORR in terms of activity and durability in both alkaline and neutral media. The Zn-air battery with the optimal Fe-NCDNA catalyst as the cathode performs impressively, delivering a power density of 184 m W cm^–2 and a specific capacity of 801 m Ah g^–1;thus, it exhibits great competitive advantages over those of the Zn-air devices employing a Pt-based cathode electrocatalyst.展开更多
Background:This study aimed to determine the reasons for conversion and elucidate the safety and efficacy of transition to tenofovir alafenamide/emtricitabine/bictegravir sodium(TAF/FTC/BIC)in highly active antiretrov...Background:This study aimed to determine the reasons for conversion and elucidate the safety and efficacy of transition to tenofovir alafenamide/emtricitabine/bictegravir sodium(TAF/FTC/BIC)in highly active antiretroviral therapy(HAART)-experienced HIV-infected patients in real-world settings.Methods:We conducted a retrospective cohort study.The treatment conversion rationales,safety,and effectiveness in 1684 HIV-infected patients with previous HAART experience who switched to TAF/FTC/BIC were evaluated at Beijing Ditan Hospital from September 2021 to Auguest 2022.Results:Regimen simplification(990/1684,58.79%)was the most common reason for switching,followed by osteoporosis or osteopenia(375/1684,22.27%),liver dysfunction(231/1684,13.72%),decline in tenofovir alafenamide/emtricitabine/elvitegravir/cobicistat(TAF/FTC/EVG/c)with food restriction(215/1684,12.77%),virological failure(116/1684,6.89%),and renal dysfunction(90/1684,5.34%).In patients receiving non-nucleotide reverse transcriptase inhibitors(NNRTI)-containing regimens,lipid panel changes 1 year after switching indicated a difference of 3.27±1.10 mmol/L vs.3.40±1.59 mmol/L in triglyceride(P=0.014),4.82±0.74 mmol/L vs.4.88±0.72 mmol/L in total cholesterol(P=0.038),3.09±0.70 mmol/L vs.3.18±0.66 mmol/L in low-density lipoprotein(P<0.001),and 0.99±0.11 mmol/L vs.0.95±0.10 mmol/L in high-density lipoprotein(P<0.001).Conversely,among patients receiving booster-containing regimens,including TAF/FTC/EVG/c and lopinavir/ritonavir(LPV/r),lipid panel changes presented decreased trends.We also observed an improved trend in viral load suppression,and alanine transaminase(ALT),aspartate transaminase(AST),estimated glomerular filtration rate(eGFR),and serum creatinine levels after the transition(P<0.001).Conclusion:The transition to TAF/FTC/BIC demonstrated good treatment potency.Furthermore,this study elucidates the motivations behind the adoption of TAF/FTC/BIC in real-world scenarios,providing clinical evidence supporting the stable conversion to TAF/FTC/BIC for HAART-experienced patients.展开更多
The fractionation of ion adsorption rare earths(IAREs) along the depth in a shaft of a deposit at Dajishan,Jiangxi, China was comparatively evaluated using the partition values(PVs) and relative fractionation values(R...The fractionation of ion adsorption rare earths(IAREs) along the depth in a shaft of a deposit at Dajishan,Jiangxi, China was comparatively evaluated using the partition values(PVs) and relative fractionation values(RFVs) of the leached rare earths(REs). It is found that both PVs and RFVs can objectively reflect the migration and fractionation of REs, but RE content and abrasion pH could not. However, the RFVs can provide more information to quantitatively evaluating the migration and fractionation characteristics of REs along the selected direction and region than PVs could, which is of significance for designing the optimal procedures of in-situ leaching based on the determined flow direction of injecting solution. It is demonstrated that the migration of Ce, Pr, and Nd along the depth direction is inert, and that of REs post Sm and Y is active. Meanwhile, the migration of La shows region characteristics which is active in the upper and inert in lower region. More interesting, the dependence of RFVs on atomic number of REs displays a tetrad group variation trend. However, the fractionation of REs among clay minerals with different particle sizes is not evident, especially for the clay in the bottom region. These results indicate that the migration and fractionation of REs not only are dominated by the adsorption of their hydrated ions, but also rely on their hydrolysis tendency, which provide information for understanding the metallogenic mechanism of IAREs.展开更多
Stock price crash sensitivity refers to the conditional probability of a stock crash when the market collapses.It focuses on individual stocks'sensitivity to the market crash and can affect stock pricing significa...Stock price crash sensitivity refers to the conditional probability of a stock crash when the market collapses.It focuses on individual stocks'sensitivity to the market crash and can affect stock pricing significantly.Although the crash sensitivity of China's stock market is very high as a whole(Weigert,2016),different individual stocks show varying degrees of crash sensitivity.This paper,adopting the perspective of institutional investors,explores the reasons for the difference in crash sensitivity in China's stock market,and finds that:First,institutional investors'shareholdings is positively related to firms'stock price crash sensitivity.However,after dividing institutional investors into professional(represented by financial institutions)and non-professional institutional investors(represented by general legal persons),we find that only professional institutional investors'shareholdings is negatively related to firms'stock price crash sensitivity.Second,the impact of professional institutional investors on the crash sensitivity is influenced by stock liquidity and media sentiment:when the stock liquidity of listed companies is good or the media sentiment is strong,the negative impact of professional institutional investors on the crash sensitivity is accordingly high.This paper,by highlighting the investor structure,attempts a pioneering exploration of the influencing factors of the difference in stock price crash sensitivity in China.Our empirical results enrich research on stock price crash sensitivity and the heterogeneity of institutional investors.They can also serve to guide regulatory authorities'development of institutional investors and efforts to maintain market stability.展开更多
文摘The application of electrocatalysts for the oxygen reduction reaction(ORR) is vital in a variety of energy conversion technologies. Exploring low-cost ORR catalysts with high activity and long-term stability is highly desirable, although it still remains challenging. Herein, we report a facile and reliable route to convert ZIF-8 modified by Fe-phenanthroline into Fe-incorporated and N-doped carbon dodecahedron nanoarchitecture(Fe-NCDNA), in which carbon nanosheets are formed in situ as the building blocks with uniform Fe-N-C species decoration. Systematic electrochemical studies demonstrate that the as-synthesized Fe-NCDNA electrocatalyst possesses highly attractive catalytic features toward the ORR in terms of activity and durability in both alkaline and neutral media. The Zn-air battery with the optimal Fe-NCDNA catalyst as the cathode performs impressively, delivering a power density of 184 m W cm^–2 and a specific capacity of 801 m Ah g^–1;thus, it exhibits great competitive advantages over those of the Zn-air devices employing a Pt-based cathode electrocatalyst.
基金supported by the Beijing Municipal Administration of Hospitals’Ascent Plan(No.DFL20191802)Beijing Municipal Administration of Hospitals Clinical Medicine Development of Special Funding Support(No.ZYLX202126)Capital’s Funds for Health Improvement and Research(No.2020-2-2174)
文摘Background:This study aimed to determine the reasons for conversion and elucidate the safety and efficacy of transition to tenofovir alafenamide/emtricitabine/bictegravir sodium(TAF/FTC/BIC)in highly active antiretroviral therapy(HAART)-experienced HIV-infected patients in real-world settings.Methods:We conducted a retrospective cohort study.The treatment conversion rationales,safety,and effectiveness in 1684 HIV-infected patients with previous HAART experience who switched to TAF/FTC/BIC were evaluated at Beijing Ditan Hospital from September 2021 to Auguest 2022.Results:Regimen simplification(990/1684,58.79%)was the most common reason for switching,followed by osteoporosis or osteopenia(375/1684,22.27%),liver dysfunction(231/1684,13.72%),decline in tenofovir alafenamide/emtricitabine/elvitegravir/cobicistat(TAF/FTC/EVG/c)with food restriction(215/1684,12.77%),virological failure(116/1684,6.89%),and renal dysfunction(90/1684,5.34%).In patients receiving non-nucleotide reverse transcriptase inhibitors(NNRTI)-containing regimens,lipid panel changes 1 year after switching indicated a difference of 3.27±1.10 mmol/L vs.3.40±1.59 mmol/L in triglyceride(P=0.014),4.82±0.74 mmol/L vs.4.88±0.72 mmol/L in total cholesterol(P=0.038),3.09±0.70 mmol/L vs.3.18±0.66 mmol/L in low-density lipoprotein(P<0.001),and 0.99±0.11 mmol/L vs.0.95±0.10 mmol/L in high-density lipoprotein(P<0.001).Conversely,among patients receiving booster-containing regimens,including TAF/FTC/EVG/c and lopinavir/ritonavir(LPV/r),lipid panel changes presented decreased trends.We also observed an improved trend in viral load suppression,and alanine transaminase(ALT),aspartate transaminase(AST),estimated glomerular filtration rate(eGFR),and serum creatinine levels after the transition(P<0.001).Conclusion:The transition to TAF/FTC/BIC demonstrated good treatment potency.Furthermore,this study elucidates the motivations behind the adoption of TAF/FTC/BIC in real-world scenarios,providing clinical evidence supporting the stable conversion to TAF/FTC/BIC for HAART-experienced patients.
基金Project supported by National Natural Science Foundation of China(21161014,51274123)National Program on Key Basic Research Project of China(973 Program,2012VBA01204)
文摘The fractionation of ion adsorption rare earths(IAREs) along the depth in a shaft of a deposit at Dajishan,Jiangxi, China was comparatively evaluated using the partition values(PVs) and relative fractionation values(RFVs) of the leached rare earths(REs). It is found that both PVs and RFVs can objectively reflect the migration and fractionation of REs, but RE content and abrasion pH could not. However, the RFVs can provide more information to quantitatively evaluating the migration and fractionation characteristics of REs along the selected direction and region than PVs could, which is of significance for designing the optimal procedures of in-situ leaching based on the determined flow direction of injecting solution. It is demonstrated that the migration of Ce, Pr, and Nd along the depth direction is inert, and that of REs post Sm and Y is active. Meanwhile, the migration of La shows region characteristics which is active in the upper and inert in lower region. More interesting, the dependence of RFVs on atomic number of REs displays a tetrad group variation trend. However, the fractionation of REs among clay minerals with different particle sizes is not evident, especially for the clay in the bottom region. These results indicate that the migration and fractionation of REs not only are dominated by the adsorption of their hydrated ions, but also rely on their hydrolysis tendency, which provide information for understanding the metallogenic mechanism of IAREs.
基金supported by the MOE(Ministry of Education in China)Youth Foundation Project of Humanities and Social Sciences(18YJC790123)the National Natural Science Foundation of China(71773100).
文摘Stock price crash sensitivity refers to the conditional probability of a stock crash when the market collapses.It focuses on individual stocks'sensitivity to the market crash and can affect stock pricing significantly.Although the crash sensitivity of China's stock market is very high as a whole(Weigert,2016),different individual stocks show varying degrees of crash sensitivity.This paper,adopting the perspective of institutional investors,explores the reasons for the difference in crash sensitivity in China's stock market,and finds that:First,institutional investors'shareholdings is positively related to firms'stock price crash sensitivity.However,after dividing institutional investors into professional(represented by financial institutions)and non-professional institutional investors(represented by general legal persons),we find that only professional institutional investors'shareholdings is negatively related to firms'stock price crash sensitivity.Second,the impact of professional institutional investors on the crash sensitivity is influenced by stock liquidity and media sentiment:when the stock liquidity of listed companies is good or the media sentiment is strong,the negative impact of professional institutional investors on the crash sensitivity is accordingly high.This paper,by highlighting the investor structure,attempts a pioneering exploration of the influencing factors of the difference in stock price crash sensitivity in China.Our empirical results enrich research on stock price crash sensitivity and the heterogeneity of institutional investors.They can also serve to guide regulatory authorities'development of institutional investors and efforts to maintain market stability.
