Carbon dioxide transformation to fuels or chemicals provides an attractive approach for its utilization as feedstock and its emission reduction. Herein, we report a gas-phase electrocatalytic reduction of CO2 in an el...Carbon dioxide transformation to fuels or chemicals provides an attractive approach for its utilization as feedstock and its emission reduction. Herein, we report a gas-phase electrocatalytic reduction of CO2 in an electrolytic cell, constructed using phosphoric acid-doped polybenz- imidazole （PBI） membrane, which allowed operation at 170 ℃ Pt/C and PtMo/C with variable ratio of Pt/Mo were studied as the cathode catalysts. The results showed that PtMo/C catalysts significantly enhanced CO formation and inhibited CH4 formation compared with Pt/C catalyst. Characterization by X-ray diffraction, X-ray photoelectron spectroscopy and transmission electron microscopy revealed that most Mo species existed as MoO3 in PtMo/C catalysts and the interaction between Pt and MoOx was likely responsible for the enhanced CO formation rate although these bicomponent catalysts in general had a larger particle size than Pt/C catalyst.展开更多
Zeolitic imidazolate frameworks（ZIFs） are widely employed in catalyst synthesis as parental materials for electrochemical energy storage and conversion. Herein, we have demonstrated a facile synthesis of highly effi...Zeolitic imidazolate frameworks（ZIFs） are widely employed in catalyst synthesis as parental materials for electrochemical energy storage and conversion. Herein, we have demonstrated a facile synthesis of highly efficient catalyst for oxygen reduction reaction in both alkaline and acidic medium, which is derived from ZIF-8 functionalized with ammonium ferric citrate via two-step pyrolysis in Ar and NHatmosphere.The results reveal that the catalytic activity improvement after NH3 pyrolysis benefits from mesoporedominated morphology and high utilization of Fe-containing active sites. The optimum catalyst shows excellent performance in zinc-air battery and polymer electrolyte membrane fuel cell tests.展开更多
收集2004年1月-2018年12月某三甲医院急诊科收治的578例胡蜂蜇伤患者临床资料并进行回顾性分析。调查内容包括胡蜂蜇伤时间、地点、针数及实验室检查结果和过敏反应情况,计算最高序贯器官衰竭评分(sequential organ failure asses, SOFA...收集2004年1月-2018年12月某三甲医院急诊科收治的578例胡蜂蜇伤患者临床资料并进行回顾性分析。调查内容包括胡蜂蜇伤时间、地点、针数及实验室检查结果和过敏反应情况,计算最高序贯器官衰竭评分(sequential organ failure asses, SOFA)。分析胡蜂蜇伤的临床特征、时空分布特征以及SOFA评分的影响因素。胡蜂蜇伤患者男性多于女性,主要发生在夏秋季节的山林和农田,蜇伤伤口以头颈部为主,患者伤后就诊时间多≥6 h,以局部疼痛、皮肤荨麻疹、消化系统症状和多器官功能障碍(multiple organ dysfunction syndrome, MODS)为主要临床表现。胡蜂蜇伤患者SOFA评分与蜇伤月份、蜇伤针数、消化系统症状呈正相关(P<0.05),消化系统症状可能是严重胡蜂蜇伤的特征性表现。展开更多
Active-phase engineering is regularly utilized to tune the selectivity of metal nanoparticles （NPs） in heterogeneous catalysis. However, the lack of understanding of the active phase in electrocatalysis has hampered...Active-phase engineering is regularly utilized to tune the selectivity of metal nanoparticles （NPs） in heterogeneous catalysis. However, the lack of understanding of the active phase in electrocatalysis has hampered the development of efficient catalysts for CO2 electroreduction. Herein, we report the systematic engineering of active phases of Pd NPs, which are exploited to select reaction pathways for CO2 electroreduction. In situ X-ray absorption spectroscopy, in situ attenuated total reflection-infrared spectroscopy, and density functional theory calculations suggest that the formation of a hydrogen-adsorbed Pd surface on a mixture of the α- and β-phases of a palladium-hydride core （α＋β PdHx@PdHx） above -0.2 V （vs. a reversible hydrogen electrode） facilitates formate production via the HCOO intermediate, whereas the formation of a metallic Pd surface on the β-phase Pd hydride core （β PdHx@Pd） below -0.5 V promotes CO production via the COOH＂ intermediate. The main product, which is either formate or CO, can be selectively produced with high Faradaic efficiencies （〉90%） and mass activities in the potential window of 0.05 to -0.9 V with scalable application demonstration.展开更多
Background：Angiotensin type 1 receptor （AT1R） antagonists are extensively used for blood pressure control in elderly patients with hypertension.This study aimed to investigate the inhibitory effects of AT1R antagon...Background：Angiotensin type 1 receptor （AT1R） antagonists are extensively used for blood pressure control in elderly patients with hypertension.This study aimed to investigate the inhibitory effects of AT1R antagonist valsartan on platelet aggregation and the occurrence of cardio-cerebral thrombotic events in elderly patients with hypertension.Methods：Two-hundred and ten patients with hypertension and aged 〉 60 years were randomized to valsartan （n =140） or amlodipine （n =70） on admission.The primary endpoint was platelet aggregation rate （PAR） induced by arachidonic acid at discharge,and the secondary endpoint was the rate of thrombotic events including brain infarction and myocardial infarction during follow-up.Human aortic endothelial cells （HAECs） were stimulated by angiotensin Ⅱ （Ang Ⅱ,100 nmol/L） with or without pretreatment of valsartan （100 nmol/L）,and relative expression of cyclooxygenase-2 （COX-2） and thromboxane B2 （TXB2） and both p38 mitogen-activated protein kinase （p38MAPK） and nuclear factor-kB （NF-kB） activities were assessed.Statistical analyses were performed by GraphPad Prism 5.0 software （GraphPad Software,Inc.,California,USA）.Results：PAR was lower after treatment with valsartan （1 1.49 ± 0.69% vs.18.71 ± 2.47%,P 〈 0.001）,associated with more reduced plasmalevels of COX-2 （76.94 ± 7.07 U/L vs.116.4 ± 15.89 U/L,P 〈 0.001） and TXB2 （1667 ± 56.50 pg/ml vs.2207 ± 180.20 pg/ml） （all P 〈 0.001）.Plasma COX-2 and TXB2 levels correlated significantly with PAR in overall patients （r =0.109,P 〈 0.001）.During follow-up （median,18 months）,there was a significantly lower thrombotic event rate in patients treated with valsartan （14.3% vs.32.8%,P =0.002）.Relative expression of COX-2 and secretion of TXB2 with concordant phosphorylation ofp38MAPK and NF-kB were increased in HAECs when stimulated by Ang Ⅱ （100 nmol/L） but were significantly decreased by valsartan pretreatment （100 nmol/L）.Conclusions：AT1R antagonist valsartan decreases platelet activity by attenuating COX-2/TXA2 expression through p38MAPK and NF-kB pathways and reduces the occurrence of cardio-cerebral thrombotic events in elderly patients with hypertension.展开更多
The oxidation of carbon monoxide is widely investigated for realistic and potential uses in energy production and environmental processes.As a probe reaction to the surface properties,it gives an insight into the rela...The oxidation of carbon monoxide is widely investigated for realistic and potential uses in energy production and environmental processes.As a probe reaction to the surface properties,it gives an insight into the relationship between the structure of active phase and catalytic performance.Noble metals alloyed with certain transition metals in the form of a nanoalloy exhibit enhanced catalytic activity for various reactions,especially when simultaneous activation of oxygen and CO is involved.This article highlights some of these insights into nanoalloy catalysts in which platinum group metal(PGM)is alloyed with a second and/or third transition metal(M/M′=Co,Fe,V,Ni,Ir,etc.),for catalytic oxidation of carbon monoxide in a gas phase.Recent studies have provided important insights into how the atomic-scale structures of the nanoalloy catalysts operate synergistically in activating oxygen and maneuvering surface oxygenated species.The exploration of atomic-scale chemical/structural ordering and coordination in correlation with the catalytic oxidation properties based on findings from ex-and in-situ synchrotron X-ray techniques is emphasized;for example,high-energy X-ray diffraction coupled to atomic-pair distribution function and X-ray absorption fine-structure spectroscopic analysis.The understanding of the detailed active sites of the nanoalloys has significant implications for the design of low-cost,active,and durable catalysts for sustainable energy production and environmental processes.展开更多
基金supported by the Ministry of Science and Technology of China(Grant No:2012CB215500 and 2013CB933100)the National Natural Science Foundation of China(Grant No:21103178 and 21033009)
文摘Carbon dioxide transformation to fuels or chemicals provides an attractive approach for its utilization as feedstock and its emission reduction. Herein, we report a gas-phase electrocatalytic reduction of CO2 in an electrolytic cell, constructed using phosphoric acid-doped polybenz- imidazole （PBI） membrane, which allowed operation at 170 ℃ Pt/C and PtMo/C with variable ratio of Pt/Mo were studied as the cathode catalysts. The results showed that PtMo/C catalysts significantly enhanced CO formation and inhibited CH4 formation compared with Pt/C catalyst. Characterization by X-ray diffraction, X-ray photoelectron spectroscopy and transmission electron microscopy revealed that most Mo species existed as MoO3 in PtMo/C catalysts and the interaction between Pt and MoOx was likely responsible for the enhanced CO formation rate although these bicomponent catalysts in general had a larger particle size than Pt/C catalyst.
基金supported by the National Natural Science Foundation of China(Grants 21573222,21622607,91545202 and U1532117)the Strategic Priority Research Program of the Chinese Academy of Sciences(Grant No.XDB17020200)+1 种基金CAS Youth Innovation PromotionK.C.Wong Education Foundation in Ningbo University
文摘Zeolitic imidazolate frameworks（ZIFs） are widely employed in catalyst synthesis as parental materials for electrochemical energy storage and conversion. Herein, we have demonstrated a facile synthesis of highly efficient catalyst for oxygen reduction reaction in both alkaline and acidic medium, which is derived from ZIF-8 functionalized with ammonium ferric citrate via two-step pyrolysis in Ar and NHatmosphere.The results reveal that the catalytic activity improvement after NH3 pyrolysis benefits from mesoporedominated morphology and high utilization of Fe-containing active sites. The optimum catalyst shows excellent performance in zinc-air battery and polymer electrolyte membrane fuel cell tests.
文摘收集2004年1月-2018年12月某三甲医院急诊科收治的578例胡蜂蜇伤患者临床资料并进行回顾性分析。调查内容包括胡蜂蜇伤时间、地点、针数及实验室检查结果和过敏反应情况,计算最高序贯器官衰竭评分(sequential organ failure asses, SOFA)。分析胡蜂蜇伤的临床特征、时空分布特征以及SOFA评分的影响因素。胡蜂蜇伤患者男性多于女性,主要发生在夏秋季节的山林和农田,蜇伤伤口以头颈部为主,患者伤后就诊时间多≥6 h,以局部疼痛、皮肤荨麻疹、消化系统症状和多器官功能障碍(multiple organ dysfunction syndrome, MODS)为主要临床表现。胡蜂蜇伤患者SOFA评分与蜇伤月份、蜇伤针数、消化系统症状呈正相关(P<0.05),消化系统症状可能是严重胡蜂蜇伤的特征性表现。
文摘Active-phase engineering is regularly utilized to tune the selectivity of metal nanoparticles （NPs） in heterogeneous catalysis. However, the lack of understanding of the active phase in electrocatalysis has hampered the development of efficient catalysts for CO2 electroreduction. Herein, we report the systematic engineering of active phases of Pd NPs, which are exploited to select reaction pathways for CO2 electroreduction. In situ X-ray absorption spectroscopy, in situ attenuated total reflection-infrared spectroscopy, and density functional theory calculations suggest that the formation of a hydrogen-adsorbed Pd surface on a mixture of the α- and β-phases of a palladium-hydride core （α＋β PdHx@PdHx） above -0.2 V （vs. a reversible hydrogen electrode） facilitates formate production via the HCOO intermediate, whereas the formation of a metallic Pd surface on the β-phase Pd hydride core （β PdHx@Pd） below -0.5 V promotes CO production via the COOH＂ intermediate. The main product, which is either formate or CO, can be selectively produced with high Faradaic efficiencies （〉90%） and mass activities in the potential window of 0.05 to -0.9 V with scalable application demonstration.
文摘Background：Angiotensin type 1 receptor （AT1R） antagonists are extensively used for blood pressure control in elderly patients with hypertension.This study aimed to investigate the inhibitory effects of AT1R antagonist valsartan on platelet aggregation and the occurrence of cardio-cerebral thrombotic events in elderly patients with hypertension.Methods：Two-hundred and ten patients with hypertension and aged 〉 60 years were randomized to valsartan （n =140） or amlodipine （n =70） on admission.The primary endpoint was platelet aggregation rate （PAR） induced by arachidonic acid at discharge,and the secondary endpoint was the rate of thrombotic events including brain infarction and myocardial infarction during follow-up.Human aortic endothelial cells （HAECs） were stimulated by angiotensin Ⅱ （Ang Ⅱ,100 nmol/L） with or without pretreatment of valsartan （100 nmol/L）,and relative expression of cyclooxygenase-2 （COX-2） and thromboxane B2 （TXB2） and both p38 mitogen-activated protein kinase （p38MAPK） and nuclear factor-kB （NF-kB） activities were assessed.Statistical analyses were performed by GraphPad Prism 5.0 software （GraphPad Software,Inc.,California,USA）.Results：PAR was lower after treatment with valsartan （1 1.49 ± 0.69% vs.18.71 ± 2.47%,P 〈 0.001）,associated with more reduced plasmalevels of COX-2 （76.94 ± 7.07 U/L vs.116.4 ± 15.89 U/L,P 〈 0.001） and TXB2 （1667 ± 56.50 pg/ml vs.2207 ± 180.20 pg/ml） （all P 〈 0.001）.Plasma COX-2 and TXB2 levels correlated significantly with PAR in overall patients （r =0.109,P 〈 0.001）.During follow-up （median,18 months）,there was a significantly lower thrombotic event rate in patients treated with valsartan （14.3% vs.32.8%,P =0.002）.Relative expression of COX-2 and secretion of TXB2 with concordant phosphorylation ofp38MAPK and NF-kB were increased in HAECs when stimulated by Ang Ⅱ （100 nmol/L） but were significantly decreased by valsartan pretreatment （100 nmol/L）.Conclusions：AT1R antagonist valsartan decreases platelet activity by attenuating COX-2/TXA2 expression through p38MAPK and NF-kB pathways and reduces the occurrence of cardio-cerebral thrombotic events in elderly patients with hypertension.
基金supported by the National Natural Science Foundation of China(21373171),DOE-BES(DE-SC0006877)the NSF(CBET-0709113,CMMI-1100736),UTC Power,and Honda
文摘The oxidation of carbon monoxide is widely investigated for realistic and potential uses in energy production and environmental processes.As a probe reaction to the surface properties,it gives an insight into the relationship between the structure of active phase and catalytic performance.Noble metals alloyed with certain transition metals in the form of a nanoalloy exhibit enhanced catalytic activity for various reactions,especially when simultaneous activation of oxygen and CO is involved.This article highlights some of these insights into nanoalloy catalysts in which platinum group metal(PGM)is alloyed with a second and/or third transition metal(M/M′=Co,Fe,V,Ni,Ir,etc.),for catalytic oxidation of carbon monoxide in a gas phase.Recent studies have provided important insights into how the atomic-scale structures of the nanoalloy catalysts operate synergistically in activating oxygen and maneuvering surface oxygenated species.The exploration of atomic-scale chemical/structural ordering and coordination in correlation with the catalytic oxidation properties based on findings from ex-and in-situ synchrotron X-ray techniques is emphasized;for example,high-energy X-ray diffraction coupled to atomic-pair distribution function and X-ray absorption fine-structure spectroscopic analysis.The understanding of the detailed active sites of the nanoalloys has significant implications for the design of low-cost,active,and durable catalysts for sustainable energy production and environmental processes.
