检索结果-南通市图书馆

Rare Metals 2022年第8期41卷 2588-2594页

作者： Zi-Ming Cao Pan-Pan Zhou Xue-Zhang Xiao Liu-Jun Zhan Zhi-Fei Jiang Shu-Mao Wang Li-Jun jiang Li-Xin Chen State Key Laboratory of Silicon Materials School of Materials Science and EngineeringZhejiang UniversityHangzhou310027China Department of Materials Science and Engineering The University of ManchesterManchesterM139PLUK Institute of Energy Materials and Technology General Research Institute for Non-ferrous MetalsBeijing100088China Key Laboratory of Advanced Materials and Applications for Batteries of Zhejiang Province Hangzhou310013China

Metal hydride with proper hydrogen storage properties is the key component of hydride thermal hydrogen compressor.In this work,Ti_(0.85)Zr_(0.17)(Cr-Mn-V)_(1.3)Fe_(0.7)-based alloys were developed to achieve thermal hydrogen compression at mild operating temperatures of water bath.The results indicate the single C 14-type Laves phase as well as homogeneously distributed elements of all alloys.With increased Mn content in Ti_(0.85)Zr_(0.17)Cr_(1.2-x)Mn_xFe_(0.7)V_(0.1)(x=0,0.1,0.2,0.3)alloys.

关键词： alloys hydrogen Laves

Discussion of 90°stopband in low-energy superconducting linear accelerators

在线全文

学校读者我要写书评

暂无评论

Nuclear Science and Techniques 2022年第9期33卷 137-147页

作者： Xin-Miao Wan Xue-jiang Pu zhi-Qiang Ren Wei-Hong Huang Yu-fei Yang zhi-Hui Li The Key Laboratory of Radiation Physics and Technology of Ministry of Education Institute of Nuclear Science and TechnologySichuan UniversityChengdu 610065China

Superconducting linear accelerators(SCL)have a high acceleration gradient and are capable of operating in a high-duty factor mode.For high-power and high-intensity SCL,the design of beam dynamics generally follows the principle that the zero-current periodic phase advance(σ0)of each degree of freedom is less than 90°to avoid envelope instability caused by space charge.However,this principle is obtained under the condition of a completely periodic focusing channel,and it is ambiguous for pseudoperiodic structures,such as linear accelerators.Although transverse beam dynamics without acceleration have been studied by other researchers,it appears that there are some connections between pure 2D and 3D beam dynamics.Based on these two points,five focusing schemes for the solenoid and quadrupole doublet channels were designed to simulate the beam behavior with non-constantσ0.Among them,the four schemes follow the characteristics of variation in the zero-current longitudinal phase advance(σ0l)under a constant acceleration gradient and synchronous phase.The zero-current transverse phase advance(σ0t)is consistent withσ0l,based on the equipartition requirement.The initialσ0twas set to 120°,110°,100°,and 90°,and was then gradually decreased to approximately 40°at the end of the channel.The last scheme maintains the maximumσ0tof88°by reducing the acceleration gradient of the corresponding cavities,until the point at whichσ0tequals88°with a normal gradient.Using the stopbands obtained from the linearized envelope equations and multiparticle particle-in-cell(PIC)simulations,the transport properties of both continuous and 3D-bunched beams with the acceleration of the five focusing schemes were studied.It was found that for a CW beam,when tune depression>0.7,σ0tcan break through 90°when the beams were transported in both solenoid and quadrupole doublet periodic focusing channels.When tune depression<0.7,the conclusions were different.For the solenoid focusing system,σ0tcan partially break through 90°,and the beam quality is not s

关键词： Proton beam Superconducting linear accelerators Envelope instability Periodic focusing structure Resonance

The protective effects and underlying mechanisms of dapagliflozin on diabetes-induced testicular dysfunction

在线全文

学校读者我要写书评

暂无评论

Asian Journal of Andrology 2023年第3期25卷 331-338页

作者： zhi-Chao Luo Zi-Run Jin Ya-fei jiang Tian-Jiao Wei Ya-Lei Cao Zhe Zhang Rui Wei Hui jiang Department of Urology Peking University Third HospitalBeijing 100191China Department of Endocrinology and Metabolism Peking University Third HospitalBeijing 100191China Department of Reproductive Medicine Center Peking University Third HospitalBeijing 100191China

Male diabetic individuals present a marked impairment in fertility;however,knowledge regarding the pathogenic mechanisms and therapeutic strategies is unsatisfactory.The new hypoglycemic drug dapagliflozin has shown certain benefits,such as decreasing the risk of cardiovascular and renal events in patients with diabetes.Even so,until now,the effects and underlying mechanisms of dapagliflozin on diabetic male infertility have awaited clarification.Here,we found that dapagliflozin lowered blood glucose levels,alleviated seminiferous tubule destruction,and increased sperm concentrations and motility in leptin receptor-deficient diabetic db/db mice.Moreover,the glucagon-like peptide-1 receptor(GLP-1R)antagonist exendin(9-39)had no effect on glucose levels but reversed the protective effects of dapagliflozin on testicular structure and sperm quality in db/db mice.We also found that dapagliflozin inhibited the testicular apoptotic process by upregulating the expression of the antiapoptotic protein B-cell lymphoma 2(BCL2)and X-linked inhibitor of apoptosis protein(XIAP)and inhibiting oxidative stress by enhancing the antioxidant status,including total antioxidant capacity,total superoxide dismutase(SOD)activity,and glutathione peroxidase(GPx)activity,as well as decreasing the level of 4-hydroxynonenal(4-HNE).Exendin(9-39)administration partially reversed these effects.Furthermore,dapagliflozin upregulated the glucagon-like peptide-1(GLP-1)level in plasma and GLP-1R expression by promoting AKT8 virus oncogene cellular homolog(Akt)phosphorylation in testicular tissue.Exendin(9-39)partially inhibited Akt phosphorylation.These results suggest that dapagliflozin protects against diabetes-induced spermatogenic dysfunction via activation of the GLP-1R/phosphatidylinositol 3-kinase(PI3K)/Akt signaling pathway.Our results indicate the potential effects of dapagliflozin against diabetes-induced spermatogenic dysfunction.

关键词： dapagliflozin diabetes glucagon-like peptide-1 receptor male infertility oxidative stress

阿魏酸对活性羰基化合物丙烯醛清除活性及机理研究（英文）

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Zhejiang University-Science B(Biomedicine & Biotechnology) 2019年第11期20卷 868-876页

作者： zhi-hao TAO Chang LI Xiao-fei XU Yuan-jiang PAN Department of Chemistry Zhejiang UniversityHangzhou 310027China College of Life Sciences Zhejiang Chinese Medical UniversityHangzhou 310053China

目的:寻找一种方便、快捷且有效的清除丙烯醛的天然试剂并研究其反应机理。创新点:发现了常见的天然酚酸阿魏酸具有有效清除丙烯醛的活性,且其反应位点与其他具有丙烯醛清除活性的酚酸类化合物不同。研究了该反应的过程,推测了其反应机... 详细信息

目的:寻找一种方便、快捷且有效的清除丙烯醛的天然试剂并研究其反应机理。创新点:发现了常见的天然酚酸阿魏酸具有有效清除丙烯醛的活性,且其反应位点与其他具有丙烯醛清除活性的酚酸类化合物不同。研究了该反应的过程,推测了其反应机理,并考察了该反应的构效关系。方法:(1)通过相同时间内阿魏酸对丙烯醛、谷胱甘肽的影响考察其清除活性;(2)运用气相色谱-质谱联用技术(GC-MS)、核磁共振技术(NMR)等技术鉴定产物结构;(3)通过研究阿魏酸、丙烯醛和反应产物之间的互相转化关系,推断该反应的过程。结论:(1)阿魏酸可以有效抑制丙烯醛对细胞抗氧化系统的破坏;(2)该反应的过程是由阿魏酸在丙烯醛作用下脱竣,得到脱竣产物,再与丙烯醛进行迈克尔加成,得到最终加合产物;(3)苯环4号位的径基对于脱竣过程是必需的;(4)苯环3号位的甲氧基可以大幅度提高加合产物的产率;(5)阿魏酸及其类似物的酯与丙烯醛不发生反应。

关键词：丙烯醛活性羰基化合物阿魏酸细胞毒性氧化应激反应

Computer tomography-guided negative pressure drainage treatment of intrathoracic esophagojejunal anastomotic leakage:A case report

在线全文

学校读者我要写书评

暂无评论

World Journal of Clinical Cases 2022年第14期10卷 4580-4585页

作者： zhi-Yang jiang Guo-Qing Tao Yan-fei Zhu Department of General Surgery The Affiliated Wuxi People's Hospital of Nanjing Medical UniversityWuxi 214023Jiangsu ProvinceChina

BACKGROUND Esophagojejunal anastomotic leakage(EJAL)is a serious and potentially crucial complication of total gastrectomy and represents the major cause of postoperative death,with a mortality rate of up to 50%.However,treatment remains challenging and controversial.We report here the case of a patient whose intrathoracic EJAL was successfully treated with computer tomography(CT)-guided negative pressure drainage treatment.CASE SUMMARY A 69-year-old male patient complained of difficulty swallowing within the last six months.He was diagnosed with esophagogastric junction carcinoma,Siewert II,cT3N0M0 stage II.Total gastrectomy and Roux-en-Y esophagojejunostomy were performed.High fever,left chest pain and dyspnea appeared on postoperative day 5,and EJAL was confirmed by CT,gastroscopy and oral blue-dimethylene tests.Conservative treatment measures were applied immediately,including antibiotics,nasojejunal tubes,and repeated thoracic puncture and drainage under ultrasound guidance.However,without sufficient and effective drainage,the thoracic infection and systemic condition continued to deteriorate.With the cooperation of multiple departments,percutaneous CT-guided drainage(24 Fr 7 mm)in the thoracic cavity was successfully placed near the anastomotic leakage.Because of continuous negative pressure suction,the infection symptoms were effectively controlled and the general situation gradually recovered.Subsequent follow-up examination showed that the patient was in good condition.CONCLUSION Negative pressure drainage via CT may represent an effective minimally invasive approach to treating intrathoracic EJAL.

关键词： Esophagojejunal anastomotic leakage Negative pressure drainage Computer tomography Intrathoracic Infection Case report

Heparin is an effective treatment for preventing liver failure after hepatectomy

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

World Journal of Gastroenterology 2024年第22期30卷 2881-2892页

作者： zhi-Ying Xu Min Peng Ming-Ming Fan Qi-fei Zou Yi-Ran Li Dong jiang Hepatic Surgery IV Shanghai Eastern Hepatobiliary Surgery HospitalThe Third Affiliated Hospital of Naval Medical UniversityShanghai 200433China Ultrasound Diagnosis PLA Naval Medical CenterShanghai 200437China Department of Ultrasound Eastern Hepatobiliary Surgery HospitalThe Third Affiliated Hospital of Naval Medical UniversityShanghai 200433China

BACKGROUND Posthepatectomy liver failure(PHLF)is one of the most important causes of death following liver resection.Heparin,an established anticoagulant,can protect liver function through a number of mechanisms,and thus,prevent liver failure.AIM To look at the safety and efficacy of heparin in preventing hepatic dysfunction after hepatectomy.METHODS The data was extracted from Multiparameter Intelligent Monitoring in Intensive Care III(MIMIC-III)v1.4 pinpointed patients who had undergone hepatectomy for liver cancer,subdividing them into two cohorts:Those who were injected with heparin and those who were not.The statistical evaluations used were unpaired ttests,Mann-Whitney U tests,chi-square tests,and Fisher’s exact tests to assess the effect of heparin administration on PHLF,duration of intensive care unit(ICU)stay,need for mechanical ventilation,use of continuous renal replacement therapy(CRRT),incidence of hypoxemia,development of acute kidney injury,and ICU mortality.Logistic regression was utilized to analyze the factors related to PHLF,with propensity score matching(PSM)aiming to balance the preoperative disparities between the two groups.RESULTS In this study,1388 patients who underwent liver cancer hepatectomy were analyzed.PSM yielded 213 matched pairs from the heparin-treated and control groups.Initial univariate analyses indicated that heparin potentially reduces the risk of PHLF in both matched and unmatched samples.Further analysis in the matched cohorts confirmed a significant association,with heparin reducing the risk of PHLF(odds ratio:0.518;95%confidence interval:0.295-0.910;P=0.022).Additionally,heparin treatment correlated with improved short-term postoperative outcomes such as reduced ICU stay durations,diminished requirements for respiratory support and CRRT,and lower incidences of hypoxemia and ICU mortality.CONCLUSION Liver failure is an important hazard following hepatic surgery.During ICU care heparin administration has been proved to decrease the occurrence of hepatectomy induced liver

关键词： Liver resection Posthepatectomy liver failure Prophylactic treatment Heparin Prognosis of hepatectomy

The scaling laws of cabin structures subjected to internal blast loading:Experimental and numerical studies

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Defence Technology（防务技术） 2022年第5期18卷 811-822页

作者： Xian-ben Ren zhi-xin Huang Yong-bo jiang Zi-hao Chen Xiao-fei Cao Tian Zhao Ying Li Beijing Key Laboratory of Lightweight Multi-functional Composite Materials and Structures Institute of Advanced Structure TechnologyBeijing Institute of TechnologyBeijing100081China State Key Laboratory of Explosion Science and Technology Beijing Institute of TechnologyBeijing100081China

This paper presents a combination of experimental and numerical investigations on the dynamic response of scaling cabin structures under internal blast loading.The purpose of this study is to modify the similar relationship between the scaled-down model and the prototype of the cabin structures under internal blast loading.According to the Hopkinson’s scaling law,three sets of cabin structure models with different scaling factors combined with different explosive masses were designed for the experimental study.The dynamic deformation process of the models was recorded by a three-dimensional digital imaging correlation(DIC)method and a 3D scanning technology was used to reconstruct the deformation modes of the specimen.In addition,a finite element model was developed for the modification of the scaling law.The experimental results showed that the final deflection-to-thickness ratio was increased with the increase of the model size despite of the similar trend of their deformation processes.The reason for this inconsistency was discussed based on the traditional scaling law and a modified formula considering of the effects of size and strain-rate was provided.

关键词： Internal blast Cabin structure Scaling law Experimental study Numerical simulation

Visible-light induced generation of bifunctional nitrogen-centered radicals:a concise synthetic strategy to construct bicyclo[3.2.1]octane and azepane cores

在线全文

学校读者我要写书评

暂无评论

Science China Chemistry 2021年第2期64卷 274-280页

作者： Wan-Lei Yu Hao-Wen jiang Lei Yan zhi-Tao Feng Yong-Chun Luo Peng-fei Xu State Key Laboratory of Applied Organic Chemistry College of Chemistry and Chemical EngineeringLanzhou UniversityLanzhou730000China Department of Chemistry University of California-DavisOne Shields AvenueDavisCA95616USA

A photocatalytic tandem cyclization of o-alkenylbenzaldehydes using pyridinium salts as the amination reagent is described.A variety of valuable seven-membered nitrogenous heterocyclic skeletons are prepared in modest to excellent yields in concise one-step.This transformation features mild reaction conditions and exceptional functional group tolerance.In addition,combining control experiments and density functional theory(DFT)calculations on the mechanism can explain the reaction selectivity.

关键词： photoredox catalysis nitrogen-centered radicals bicyclo[3.2.1]octane azepane 1,5-hydrogen atom transfer

(±)-Atrachinenins A-C,Three Pairs of Caged C_(27) Meroterpenoids from the Rhizomes of Atractylodes chinensis

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Chemistry 2022年第4期40卷 460-466页

作者： fei-Long Chen Dong-Li Liu Jing Fu Ji Yang Li-Ping Bai Wei Zhang zhi-Hong jiang Guo-Yuan Zhu Key Laboratory of Quality Research in Chinese Medicine Guangdong-Hong Kong-Macao Joint Laboratory of Respiratory Infectious DiseaseMacao Institute for Applied Research in Medicine and HealthMacao University of Science and TechnologyMacaoChina

Comprehensive Summary(±)-Atrachinenins A—C(1—3),three meroterpenoids possessing novel C_(27) skeletons,were isolated from the rhizomes of Atractylodes chinensis.(±)-Atrachinenin A(1)possesses an unprecedented cage-like skeleton with a fused 6/6/5/5 tetracyclic system(decahy-dro-1,5:4a,7-dimethanobenzo[7]annulene),which may be formed by the intermolecular cyclization of(±)-atrachinenin C(3).

关键词： Atractylodes chinensis Terpenoids Phytochemistry Natural products TGF-β

Enhanced tensile properties and wear resistance of additively manufactured CoCrFeMnNi high-entropy alloy at cryogenic temperature

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Rare Metals 2022年第4期41卷 1210-1216页

作者： Hong-Ge Li Peng-Cheng Che Xiao-Kun Yang Yong-jiang Huang zhi-Liang Ning Jian-fei Sun Hong-Bo Fan School of Materials Science and Engineering Harbin Institute of TechnologyHarbin 150001China Harbin-Electric Power Generation Equipment National Engineering Research Center Co. LtdHarbin 150028China

Here,bulk CoCrFeMnNi high-entropy alloy was prepared via laser melting deposition,and its microstructure and mechanical properties at room and cryogenic temperature were investigated by a series of microstructural character-izations and mechanical tests.The results showed that the as-built samples possessed a single fcc phase and highly dense microstructures.Compared to the mechanical prop-erties at room temperature,tensile properties,microhard-ness and wear resistance of the as-built samples showed a signiflcant enhancement at cryogenic temperature,which was attributed to the deformation mechanism converting from dislocation slipping to deformation twinning at cryogenic temperature.The formation of deformation nanotwins signiflcantly improved the deformation resis-tance in cryogenic conditions,and the sliding wear in the liquid nitrogen could decrease the oxygen concentration,suppress the generation of oxide particles and thus enhance the wear resistance.

关键词： wear cryogenic alloy