The Moon provides a unique environment for investigating nearby astrophysical events such as supernovae.Lunar samples retain valuable information from these events,via detectable long-lived“fingerprint”radionuclides...The Moon provides a unique environment for investigating nearby astrophysical events such as supernovae.Lunar samples retain valuable information from these events,via detectable long-lived“fingerprint”radionuclides such as^(60)Fe.In this work,we stepped up the development of an accelerator mass spectrometry(AMS)method for detecting^(60)Fe using the HI-13tandem accelerator at the China Institute of Atomic Energy(CIAE).Since interferences could not be sufficiently removed solely with the existing magnetic systems of the tandem accelerator and the following Q3D magnetic spectrograph,a Wien filter with a maximum voltage of±60 kV and a maximum magnetic field of 0.3 T was installed after the accelerator magnetic systems to lower the detection background for the low abundance nuclide^(60)Fe.A 1μm thick Si_(3)N_(4) foil was installed in front of the Q3D as an energy degrader.For particle detection,a multi-anode gas ionization chamber was mounted at the center of the focal plane of the spectrograph.Finally,an^(60)Fe sample with an abundance of 1.125×10^(-10)was used to test the new AMS system.These results indicate that^(60)Fe can be clearly distinguished from the isobar^(60)Ni.The sensitivity was assessed to be better than 4.3×10^(-14)based on blank sample measurements lasting 5.8 h,and the sensitivity could,in principle,be expected to be approximately 2.5×10^(-15)when the data were accumulated for 100 h,which is feasible for future lunar sample measurements because the main contaminants were sufficiently separated.展开更多
Toluene methylation with methanol to produce para-xylene has been extensively and intensively studied.However,the methanol-to-hydrocarbons(MTH)side reaction in this reaction is difficult to be inhibited,which will cau...Toluene methylation with methanol to produce para-xylene has been extensively and intensively studied.However,the methanol-to-hydrocarbons(MTH)side reaction in this reaction is difficult to be inhibited,which will cause a mass of carbon deposition and cover the catalyst surface,resulting in catalyst deactivation.Here,a dual-functional Ru@HZSM-5 catalyst with high para-selectivity and low carbon deposition was prepared by encapsulating Ru metal with HZSM-5.According to catalytic performance studies,the Ru@HZSM-5 catalyst produced xylene selectivity of 98%and para-xylene selectivity of 96%.Meanwhile,we find that carbon precursors(e.g.ethylene)were very little when Ru catalyst was used,but the results of HZSM-5 catalyst were completely opposite.Ru@HZSM-5 catalyst achieves a lower carbon deposition rate of only 6%of HZSM-5.The main possible reason for this is that the initial C-C bond between methanol and the olefin is difficult to form.展开更多
目的:观察抗VEGF联合激光治疗视网膜静脉阻塞合并黄斑水肿的临床疗效。方法:选取2017-03/09在我院眼科确诊的视网膜静脉阻塞合并黄斑水肿患者62例62眼,随机进行分组,A组行单纯视网膜激光治疗,B组和C组先分别行玻璃体腔注射康柏西普和雷...目的:观察抗VEGF联合激光治疗视网膜静脉阻塞合并黄斑水肿的临床疗效。方法:选取2017-03/09在我院眼科确诊的视网膜静脉阻塞合并黄斑水肿患者62例62眼,随机进行分组,A组行单纯视网膜激光治疗,B组和C组先分别行玻璃体腔注射康柏西普和雷珠单抗,再进行视网膜激光治疗。随访6mo,观察三组患者的临床疗效。结果:治疗后三组患者黄斑中心视网膜厚度(CMT)均较治疗前显著降低,且B组和C组患者CMT均低于A组( P < 0.05),但两组之间无差异( P >0.05)。治疗后6mo,三组患者治疗总有效率分别为44%、86%、86%( P <0.05),B组和C组患者治疗总有效率均高于A组( P <0.0167)。结论:玻璃体腔注射康柏西普或雷珠单抗联合视网膜激光治疗视网膜静脉阻塞合并黄斑水肿可有效减轻黄斑水肿,改善视力,疗效相似。展开更多
Pulmonary hypertension(PH)is a progressive disorder affecting the pulmonary circulation,characterized by a grim prognosis that often culminates in right heart failure and mortality.Pulmonary vascular remodeling stands...Pulmonary hypertension(PH)is a progressive disorder affecting the pulmonary circulation,characterized by a grim prognosis that often culminates in right heart failure and mortality.Pulmonary vascular remodeling stands out as the predominant feature in the pathogenesis and pathological alterations of PH.Whereas,the pathogenic factors of PH are intricate,involving multiple interacting elements,and the mechanism behind pulmonary vascular remodeling remains not entirely comprehended.In this context,inflammation,chemokines,and gut microbiota may make a intricate and interrelated difference during the process of pulmonary vascular remodeling.展开更多
目的探讨不同麻醉维持方式对加速康复外科(enhanced recovery after surgery,ERAS)模式下机器人辅助小儿肾盂成形手术围术期的影响。方法选取2020年10月至2021年10月于解放军总医院第七医学中心接受机器人辅助腹腔镜下肾盂成形术的3~12...目的探讨不同麻醉维持方式对加速康复外科(enhanced recovery after surgery,ERAS)模式下机器人辅助小儿肾盂成形手术围术期的影响。方法选取2020年10月至2021年10月于解放军总医院第七医学中心接受机器人辅助腹腔镜下肾盂成形术的3~12岁肾积水患儿纳入研究。随机分为静脉麻醉维持组(n=30)和吸入麻醉维持组(n=29)。比较两组患儿的围术期血流动力学、术后苏醒时间、苏醒期躁动评分和疼痛情况、术后不良反应的差异性。统计学方法采用重复测量方差分析、t检验、秩和检验、χ^(2)检验或Fisher确切概率法。结果①重复测量方差分析显示,静脉组与吸入组麻醉维持患儿围术期不同时间点平均动脉压[气腹5 min:(83±10)、(81±8)mmHg,拔管后即刻(:81±10)、(87±8)mmHg]、心率[切皮前:(78±16)、(88±11)次/min,拔管后即刻(:123±18)、(125±13)次/min]比较,差异均有统计学意义(平均动脉压:F组内=10.174,P<0.001;F_(组间)=4.880,P=0.031;F_(交互)=2.393,P=0.042;心率:F组内=61.159,P<0.001;F_(组间)=15.956,P<0.001;F_(交互)=5.129,P<0.001)。②静脉组麻醉维持患儿术后拔管时间显著长于吸入组[(31±13)、(23±7)min,t=2.872,P=0.006]。③两组患儿拔管后各时间段的躁动评分比较,差异均无统计学意义(P值均>0.05)。静脉组麻醉维持患儿术后1 h无痛比例显著高于吸入组(66.7%、37.9%,Z=-2.262,P<0.05)。④两组患儿术后不良反应发生率比较,差异无统计学意义(P>0.05)。结论在ERAS模式下行机器人辅助腹腔镜下肾盂成形术的儿童中,与吸入麻醉维持相比,静脉麻醉维持患儿苏醒时间较长,但围术期血流动力学更稳定,术后疼痛程度更低。展开更多
基金supported by the National Natural Science Foundation of China(Nos.12125509,12222514,11961141003,and 12005304)National Key Research and Development Project(No.2022YFA1602301)+1 种基金CAST Young Talent Support Planthe CNNC Science Fund for Talented Young Scholars Continuous support for basic scientific research projects。
文摘The Moon provides a unique environment for investigating nearby astrophysical events such as supernovae.Lunar samples retain valuable information from these events,via detectable long-lived“fingerprint”radionuclides such as^(60)Fe.In this work,we stepped up the development of an accelerator mass spectrometry(AMS)method for detecting^(60)Fe using the HI-13tandem accelerator at the China Institute of Atomic Energy(CIAE).Since interferences could not be sufficiently removed solely with the existing magnetic systems of the tandem accelerator and the following Q3D magnetic spectrograph,a Wien filter with a maximum voltage of±60 kV and a maximum magnetic field of 0.3 T was installed after the accelerator magnetic systems to lower the detection background for the low abundance nuclide^(60)Fe.A 1μm thick Si_(3)N_(4) foil was installed in front of the Q3D as an energy degrader.For particle detection,a multi-anode gas ionization chamber was mounted at the center of the focal plane of the spectrograph.Finally,an^(60)Fe sample with an abundance of 1.125×10^(-10)was used to test the new AMS system.These results indicate that^(60)Fe can be clearly distinguished from the isobar^(60)Ni.The sensitivity was assessed to be better than 4.3×10^(-14)based on blank sample measurements lasting 5.8 h,and the sensitivity could,in principle,be expected to be approximately 2.5×10^(-15)when the data were accumulated for 100 h,which is feasible for future lunar sample measurements because the main contaminants were sufficiently separated.
基金financial support from the Hongliu Outstanding Young Talents Funding Program of Lanzhou University of Technology(02/062214)。
文摘Toluene methylation with methanol to produce para-xylene has been extensively and intensively studied.However,the methanol-to-hydrocarbons(MTH)side reaction in this reaction is difficult to be inhibited,which will cause a mass of carbon deposition and cover the catalyst surface,resulting in catalyst deactivation.Here,a dual-functional Ru@HZSM-5 catalyst with high para-selectivity and low carbon deposition was prepared by encapsulating Ru metal with HZSM-5.According to catalytic performance studies,the Ru@HZSM-5 catalyst produced xylene selectivity of 98%and para-xylene selectivity of 96%.Meanwhile,we find that carbon precursors(e.g.ethylene)were very little when Ru catalyst was used,but the results of HZSM-5 catalyst were completely opposite.Ru@HZSM-5 catalyst achieves a lower carbon deposition rate of only 6%of HZSM-5.The main possible reason for this is that the initial C-C bond between methanol and the olefin is difficult to form.
文摘目的:观察抗VEGF联合激光治疗视网膜静脉阻塞合并黄斑水肿的临床疗效。方法:选取2017-03/09在我院眼科确诊的视网膜静脉阻塞合并黄斑水肿患者62例62眼,随机进行分组,A组行单纯视网膜激光治疗,B组和C组先分别行玻璃体腔注射康柏西普和雷珠单抗,再进行视网膜激光治疗。随访6mo,观察三组患者的临床疗效。结果:治疗后三组患者黄斑中心视网膜厚度(CMT)均较治疗前显著降低,且B组和C组患者CMT均低于A组( P < 0.05),但两组之间无差异( P >0.05)。治疗后6mo,三组患者治疗总有效率分别为44%、86%、86%( P <0.05),B组和C组患者治疗总有效率均高于A组( P <0.0167)。结论:玻璃体腔注射康柏西普或雷珠单抗联合视网膜激光治疗视网膜静脉阻塞合并黄斑水肿可有效减轻黄斑水肿,改善视力,疗效相似。
文摘Pulmonary hypertension(PH)is a progressive disorder affecting the pulmonary circulation,characterized by a grim prognosis that often culminates in right heart failure and mortality.Pulmonary vascular remodeling stands out as the predominant feature in the pathogenesis and pathological alterations of PH.Whereas,the pathogenic factors of PH are intricate,involving multiple interacting elements,and the mechanism behind pulmonary vascular remodeling remains not entirely comprehended.In this context,inflammation,chemokines,and gut microbiota may make a intricate and interrelated difference during the process of pulmonary vascular remodeling.
