Single metal atoms anchored on nitrogen-doped carbon materials(M-N_(4))have been identified as effective active sites for catalyzing the two-electron oxygen reduction reaction(2e-ORR).However,the relationship between ...Single metal atoms anchored on nitrogen-doped carbon materials(M-N_(4))have been identified as effective active sites for catalyzing the two-electron oxygen reduction reaction(2e-ORR).However,the relationship between the local atomic/electronic environments of the M-N_(4) sites(metal atoms coordinated with different types of N species)and their catalytic activity for 2e-ORR has rarely been elaborated clearly,which imposes significant ambiguity for the rational design of catalysts.Herein,guided by the comprehensive density-functional theory calculations and predictions,a series of Zn-N_(4) single-atom catalysts(SACs)are designed with pyrrole/pyridine-N(N_(Po)/N_(Pd))synergistic coordination and prepared by controlling the pyrolysis temperature(600,700,and 800℃),Among them,the dominated Zn-N_(4) configurations with rationally combined N_(Po)/N_(Pd)coordination show~*OOH adsorption strength close to the optimal value,much superior to those with mono N species.Thus,the as-prepared catalyst exhibits a high H_(2)O_(2) selectivity of over 90%both in neutral and alkaline environments,with a superb H_(2)O_(2) yield of up to 33.63 mol g^(-1)h^(-1)in an alkaline with flow cell.More importantly,a new descriptor,dz^(2)+s band center,has been proposed,which is especially feasible for predicting the activity for metal types with fully occupied s and d orbitals.This work thus presents clear guidance for the rational design of highly active SACs toward ORR and provides a complement to the d-band theory for more accurately predicting the catalytic activity of the materials.展开更多
BACKGROUND Anti-D antibody is not the common cause of Rh-isoimmunization in Chinese neonatal jaundice.Recent change in national population policy has followed by an increase in Rh-isoimmunization related hemolytic dis...BACKGROUND Anti-D antibody is not the common cause of Rh-isoimmunization in Chinese neonatal jaundice.Recent change in national population policy has followed by an increase in Rh-isoimmunization related hemolytic disease of the newborn(HDN).Unfortunately,regional status of Rh-HDN is unavailable.We hypothesize that Rh-HDN in our region is most commonly due to anti-E antibody.AIM To investigate the prevalence of hemolytic disease of the newborn due to Rhisoimmunization in Hefei City.METHODS Retrospective review of data obtained from Children’s Hospital of Anhui and Hefei Blood Center between January 2017 and June 2019.Status of minor blood group antibody was studied in the corresponding mothers.RESULTS Totally 4138 newborns with HDN admitted during the study period and 116(2.8%)received blood exchange transfusion(BET).Eighteen newborns(0.43%)with proven Rh-incompatible HDN were identified.All were not the first-born baby.Thirteen mothers were RhD(+)(72%)and five were RhD(-).The distribution of Rh-related antibodies in mothers was ten anti-E(55%),five anti-D(27%),and for one anti-C,anti-c,and anti-E/c(6%)each.Thirteen(72.2%)were qualified for BET,relative risk for BET was 28.9 as compared to other types of HDN,but only 10 received due to parenteral refusal.All(100%)RhD related HDN received BET which is not significantly different from RhE related HDN(81.8%).CONCLUSION As expected,all Rh-incompatible HDN newborns were not the first-born.Contrary to the Caucasian population,anti-D induced HDN is not the most common etiology.In our region,anti-E(11/18,61%)is the most common cause of Rh-HDN.展开更多
Manipulation of light-matter interaction is critical in modern physics, especially in the strong coupling regime, where the generated half-light, half-matter bosonic quasiparticles as polaritons are important for fund...Manipulation of light-matter interaction is critical in modern physics, especially in the strong coupling regime, where the generated half-light, half-matter bosonic quasiparticles as polaritons are important for fundamental quantum science and applications of optoelectronics and nonlinear optics. Two-dimensional transition metal dichalcogenides (TMDs) are ideal platforms to investigate the strong coupling because of their huge exciton binding energy and large absorption coefficients. Further studies on strong exciton-plasmon coupling by combining TMDs with metallic nanostructures have generated broad interests in recent years. However, because of the huge plasmon radiative damping, the observation of strong coupling is significantly limited at room temperature. Here, we demonstrate that a large Rabi splitting (~300 meV) can be achieved at ambient conditions in the strong coupling regime by embedding Ag-WS2 heterostructure in an optical microcavity. The generated quasiparticle with part-plasmon, part-exciton and part-light is analyzed with Hopfield coefficients that are calculated by using three-coupled oscillator model. The resulted plasmon-exciton polaritonic hybrid states can efficiently enlarge the obtained Rabi splitting, which paves the way for the practical applications of polaritonic devices based on ultrathin materials.展开更多
Hyperhomocysteinemia(HHcy)causes oxidative stress, induces apoptosis, and leads to damage to the vascular endothelium is the starting point of atherosclerosis. Pterostilbene(Pte)has been reported to have antioxidant a...Hyperhomocysteinemia(HHcy)causes oxidative stress, induces apoptosis, and leads to damage to the vascular endothelium is the starting point of atherosclerosis. Pterostilbene(Pte)has been reported to have antioxidant and anti-apoptotic effects under various pathological conditions. The purpose of this study was to explore whether Pte can inhibit the oxidative stress and apoptosis of vascular endothelium induced by homocysteine(Hcy)and to explain the possible mechanism by which it occurs. The results showed that 20 μmol/L Pte significantly reduced the accumulation of reactive oxygen species, malondialdehyde, and lipids in cells induced by Hcy and promoted the activities of superoxide dismutase and catalase. The Hoechst 33342/PI staining assay showed that Pte antagonized Hcy-induced apoptosis. Pte inhibited Hcy-induced Akt dephosphorylation, increased p53, and decreased the Bcl-2/Bax ratio and caspase-9/caspase-3 activation in a dose-dependent manner. LY294002 pretreatment partially reversed the protective effect of Pte by blocking the PI3K/Akt pathway. Moreover, Pte reduced lipid deposition in human umbilical vein endothelial cells(HUVECs). This study proposes that Pte can inhibit Hcy-induced oxidative stress and apoptosis of HUVECs, and the PI3K/Akt/p53 signaling pathway of apoptosis was revealed. These results suggest that Pte exhibits significant potential for dealing with HHcy-induced vascular endothelial injury, such as atherosclerosis.展开更多
Supercontinuum (SC) generation has attracted a significant scientific interest in the past decades due to its promising applications covering the fields of metrology, spectroscopy, defense, as well as medical treatmen...Supercontinuum (SC) generation has attracted a significant scientific interest in the past decades due to its promising applications covering the fields of metrology, spectroscopy, defense, as well as medical treatments. To date, researchers are devoted to improving the spectral width and flatness of SC generation by using specialty optical fibers. The flatness of the spectrum is of importance because it can improve the accuracy of measurement in practical applications. This paper summarizes the theory of SC, the state of the art of flat SC generation using optical fiber including photonic crystal fibers, soft glass fibers as well as germania-doped fibers, and suggests the future research direction of flat SC light source.展开更多
基金National Natural Science Foundation of China(No.22379111 and 22179093)。
文摘Single metal atoms anchored on nitrogen-doped carbon materials(M-N_(4))have been identified as effective active sites for catalyzing the two-electron oxygen reduction reaction(2e-ORR).However,the relationship between the local atomic/electronic environments of the M-N_(4) sites(metal atoms coordinated with different types of N species)and their catalytic activity for 2e-ORR has rarely been elaborated clearly,which imposes significant ambiguity for the rational design of catalysts.Herein,guided by the comprehensive density-functional theory calculations and predictions,a series of Zn-N_(4) single-atom catalysts(SACs)are designed with pyrrole/pyridine-N(N_(Po)/N_(Pd))synergistic coordination and prepared by controlling the pyrolysis temperature(600,700,and 800℃),Among them,the dominated Zn-N_(4) configurations with rationally combined N_(Po)/N_(Pd)coordination show~*OOH adsorption strength close to the optimal value,much superior to those with mono N species.Thus,the as-prepared catalyst exhibits a high H_(2)O_(2) selectivity of over 90%both in neutral and alkaline environments,with a superb H_(2)O_(2) yield of up to 33.63 mol g^(-1)h^(-1)in an alkaline with flow cell.More importantly,a new descriptor,dz^(2)+s band center,has been proposed,which is especially feasible for predicting the activity for metal types with fully occupied s and d orbitals.This work thus presents clear guidance for the rational design of highly active SACs toward ORR and provides a complement to the d-band theory for more accurately predicting the catalytic activity of the materials.
文摘BACKGROUND Anti-D antibody is not the common cause of Rh-isoimmunization in Chinese neonatal jaundice.Recent change in national population policy has followed by an increase in Rh-isoimmunization related hemolytic disease of the newborn(HDN).Unfortunately,regional status of Rh-HDN is unavailable.We hypothesize that Rh-HDN in our region is most commonly due to anti-E antibody.AIM To investigate the prevalence of hemolytic disease of the newborn due to Rhisoimmunization in Hefei City.METHODS Retrospective review of data obtained from Children’s Hospital of Anhui and Hefei Blood Center between January 2017 and June 2019.Status of minor blood group antibody was studied in the corresponding mothers.RESULTS Totally 4138 newborns with HDN admitted during the study period and 116(2.8%)received blood exchange transfusion(BET).Eighteen newborns(0.43%)with proven Rh-incompatible HDN were identified.All were not the first-born baby.Thirteen mothers were RhD(+)(72%)and five were RhD(-).The distribution of Rh-related antibodies in mothers was ten anti-E(55%),five anti-D(27%),and for one anti-C,anti-c,and anti-E/c(6%)each.Thirteen(72.2%)were qualified for BET,relative risk for BET was 28.9 as compared to other types of HDN,but only 10 received due to parenteral refusal.All(100%)RhD related HDN received BET which is not significantly different from RhE related HDN(81.8%).CONCLUSION As expected,all Rh-incompatible HDN newborns were not the first-born.Contrary to the Caucasian population,anti-D induced HDN is not the most common etiology.In our region,anti-E(11/18,61%)is the most common cause of Rh-HDN.
基金the National Key Research and Development Program of China (Grant No. 2017YFA0205700)National Basic Research Program of China (Grant No. 2015CB932403, 2017YFA0206000)+3 种基金National Natural Science Foundation of China (Grant Nos. 11674012, 61521004, 21790364, 61422501, and 11374023)Beijing Natural Science Foundation (Z180011, and L140007)Foundation for the Author of National Excellent Doctoral Dissertation of PR China (Grant No. 201420)National Program for Support of Top-notch Young Professionals (Grant No. W02070003).
文摘Manipulation of light-matter interaction is critical in modern physics, especially in the strong coupling regime, where the generated half-light, half-matter bosonic quasiparticles as polaritons are important for fundamental quantum science and applications of optoelectronics and nonlinear optics. Two-dimensional transition metal dichalcogenides (TMDs) are ideal platforms to investigate the strong coupling because of their huge exciton binding energy and large absorption coefficients. Further studies on strong exciton-plasmon coupling by combining TMDs with metallic nanostructures have generated broad interests in recent years. However, because of the huge plasmon radiative damping, the observation of strong coupling is significantly limited at room temperature. Here, we demonstrate that a large Rabi splitting (~300 meV) can be achieved at ambient conditions in the strong coupling regime by embedding Ag-WS2 heterostructure in an optical microcavity. The generated quasiparticle with part-plasmon, part-exciton and part-light is analyzed with Hopfield coefficients that are calculated by using three-coupled oscillator model. The resulted plasmon-exciton polaritonic hybrid states can efficiently enlarge the obtained Rabi splitting, which paves the way for the practical applications of polaritonic devices based on ultrathin materials.
基金supported by the Zhejiang Lanmei Technology Co.,Ltd.,National Natural Science Foundation of China (U21A20273)“China Agriculture Research System of MOF and MARA (CARS-29)”the First Batch of Liaoning “Unveiling Leader” Scientific and Technological Projects (2021JH1/10400036)。
文摘Hyperhomocysteinemia(HHcy)causes oxidative stress, induces apoptosis, and leads to damage to the vascular endothelium is the starting point of atherosclerosis. Pterostilbene(Pte)has been reported to have antioxidant and anti-apoptotic effects under various pathological conditions. The purpose of this study was to explore whether Pte can inhibit the oxidative stress and apoptosis of vascular endothelium induced by homocysteine(Hcy)and to explain the possible mechanism by which it occurs. The results showed that 20 μmol/L Pte significantly reduced the accumulation of reactive oxygen species, malondialdehyde, and lipids in cells induced by Hcy and promoted the activities of superoxide dismutase and catalase. The Hoechst 33342/PI staining assay showed that Pte antagonized Hcy-induced apoptosis. Pte inhibited Hcy-induced Akt dephosphorylation, increased p53, and decreased the Bcl-2/Bax ratio and caspase-9/caspase-3 activation in a dose-dependent manner. LY294002 pretreatment partially reversed the protective effect of Pte by blocking the PI3K/Akt pathway. Moreover, Pte reduced lipid deposition in human umbilical vein endothelial cells(HUVECs). This study proposes that Pte can inhibit Hcy-induced oxidative stress and apoptosis of HUVECs, and the PI3K/Akt/p53 signaling pathway of apoptosis was revealed. These results suggest that Pte exhibits significant potential for dealing with HHcy-induced vascular endothelial injury, such as atherosclerosis.
基金National Natural Science Foundation of China (Grant No. 61605108, 61735009, 61422507)Young Oriental Scholarship of Shanghai.
文摘Supercontinuum (SC) generation has attracted a significant scientific interest in the past decades due to its promising applications covering the fields of metrology, spectroscopy, defense, as well as medical treatments. To date, researchers are devoted to improving the spectral width and flatness of SC generation by using specialty optical fibers. The flatness of the spectrum is of importance because it can improve the accuracy of measurement in practical applications. This paper summarizes the theory of SC, the state of the art of flat SC generation using optical fiber including photonic crystal fibers, soft glass fibers as well as germania-doped fibers, and suggests the future research direction of flat SC light source.
