检索结果-南通市图书馆

Science China Chemistry 2012年第6期55卷 1134-1139页

作者： li Sen wang Kuan chang Kue-Chieh Alan ZONG Ming wang jing cao YongGang BAI YuHua wei TaiMing zhang ZhiRen School of Pharmacy Daqing Campus Harbin Medical University Daqing 163319 China School of life Science and Biotechnology Dalian University of Technology Dalian 116024 China Departments of Pharmacy and Cardiology The 2nd Affiliated Hospital of Harbin Medical University Key Laboratories of Ministry of Education for Myocardial lschemia Mechanism and Treatment Harbin Medical University Harbin 150086 China

A novel vehicle for the delivery of aspirin （ASA） was prepared from porous nano-hydroxyapafite/poly（styrene-divinylbenzene） [nano-HAP/P（St-DVB）] composite microspheres by grafting nano-HAP [Ca10（PO4）6（OH）2] onto porous P（St-DVB） micro- spheres. Four types of porous composite microspheres were prepared, each with different nano-HAP contents. The ASA-loaded composite microspheres prepared with 10% and 15% nano-HAP （mass ratio） exhibited excellent buoyancy with relatively short instantaneous floating time （within l0 min） and a long sustained floating time （12 h） in simulated gastric juice. They also offered good sustained release of ASA （up to 8 h）. Furthermore, these composite microspheres displayed good buff- ering capacity that prevented the buildup of acidity caused by hydrolysis of ASA, keeping the pH of gastric juice within the normal range （pH 0.9 to 1.5）. The results showed that porous nano-HAP/P（St-DVB） composite microspheres prepared with 10% and 15% nano-HAP could be used as a novel drug carrier for ASA, providing a sustained release dose without leading to stomach irritation, a side effect that is often associated with ASA medication.

关键词： porous nano-hydroxyapatite microsphere carrier aspirin

Se-alloying reducing lattice thermal conductivity of Ge_(0.95)Bi_(0.05)Te

在线全文

学校读者我要写书评

暂无评论

Journal of Materials Science & Technology 2022年第11期106卷 249-256页

作者： De-Zhuang wang wei-Di liu Xiao-Lei Shi Han Gao Hao Wu liang-cao yin Yuewen zhang Yifeng wang Xueping Wu Qingfeng liu Zhi-Gang Chen State Key Laboratory of Materials-Oriented Chemical Engineering College of Chemical EngineeringNanjing Tech UniversityNanjing211800China Centre for Future Materials University of Southern QueenslandSpringfield CentralQLD 4300Australia School of Mechanical and Mining Engineering The University of QueenslandBrisbaneQLD 4072Australia Key Laboratory of Material Physics of Ministry of Education School of Physics and MicroelectronicsZhengzhou UniversityZhengzhou450052China College of Materials science and engineering Nanjing Tech UniversityNanjing211800China School of Chemistry and Chemical Engineering Hefei University of TechnologyHefei230009China CAS Key Laboratory of Carbon Materials Institute of Coal ChemistryChinese Academy of SciencesTaiyuan030001China

High lattice thermal conductivity of intrinsic GeTe limits the wide application of GeTe-based ***,the optimization of GeTe-based thermoelectric materials has been focusing on reducing lattice thermal conductivity via strengthening phonon *** this study,we systematically studied thermoelectric properties of Se-alloyed Ge_(0.95) Bi_(0.05) Te via theoretical calculations,structural characterizations,and performance *** results indicate that Se-alloying can induce dense point defects with mass/strain-field fluctuations and correspondingly enhance point defect phonon scattering of the Ge_(0.95) Bi_(0.05) Te ***-alloying might also change chemical bonding strength to introduce resonant states in the base frequency of Ge_(0.95) Bi_(0.05) Te matrix,which can strengthen Umklapp phonon ***,a decreased lattice thermal conductivity from∼1.02 W m^(−1) K^(−1) to∼0.65 W m^(−1) K^(−1) at 723 K is obtained in Ge_(0.95) Bi_(0.05) Te_(1-x) Se_(x) pellets with increasing the Se content from 0 to 0.3.A peak figure of merit of∼1.6 at 723 K is achieved in Ge_(0.95) Bi_(0.05) Te_(0.7) Se_(0.3) pellet,which is∼77%higher than that of pristine *** study extends the understanding on the thermoelectric performance of GeTe.

关键词： Thermoelectric GeTe Se-alloying Lattice thermal conductivity

Block copolymer assisted topochemical polymerization:A facile and efficient route to robust polymeric nanoporous membranes decorated with versatile amino acids

在线全文

学校读者我要写书评

暂无评论

Chinese Chemical Letters 2020年第3期31卷 885-889页

作者： Yun liang Wanyue Ouyang Peng wang Wanlin zhang Shiqiang wang li Tian Yong ju Guangtao li Key Lab of Organic Optoelectronics and Molecular Engineering Department of ChemistryTsinghua UniversityBeijing 100084China

Based on block copolymer assisted topochemical polymerization,a new strategy for facilely producing robust nanoporous membranes with controlled incorporation of functional groups onto nanopores is *** exemplified by preparing nanoporous polypyrrole decorated with amino acids,this strategy exhibits a high degree of freedom for tailoring the surface functionality in the created pores.

关键词： Block copolymer Supramolecular ensemble Topochemical polymerization Nanoporous membranes Pore functionalization

Evaluation of drought tolerance in ZmVPP1-overexpressing transgenic inbred maize lines and their hybrids

在线全文

学校读者我要写书评

暂无评论

Journal of Integrative Agriculture 2020年第9期19卷 2177-2187页

作者： JIA Teng-jiao li jing-jing wang li-feng cao Yan-yong MA juan wang Hao zhang Deng-feng li Hui-yong Institute of Cereal Crop Henan Academy of Agricultural SciencesZhengzhou 450002P.R.China Institute of Crop Sciences Chinese Academy of Agricultural SciencesBeijing 100089P.R.China

The vacuolar proton-pumping pyrophosphatase gene(VPP)is often used to enhance plant drought tolerance via genetic *** this study,the drought tolerance of four transgenic inbred maize lines overexpressing ZmVPP1(PH4CV-T,PH6WC-T,chang7-2-T,and Zheng58-T)and their transgenic hybrids was evaluated at various *** normal and drought conditions,the height and fresh weight were greater for the four transgenic inbred maize lines than for the wild-type(WT)controls at the germination and seedling ***,the transgenic plants exhibited enhanced photosynthetic efficiency at the seedling *** irrigated and non-irrigated fields,the four transgenic lines grew normally,but with increased ear weight and yield compared with the WT ***,the ear weight and yield of the transgenic hybrids resulting from the PH4CV-T×PH6WC-W and chang7-2-T×Zheng58-W crosses increased in the non-irrigated *** results demonstrated that the growth and drought tolerance of four transgenic inbred maize lines with improved photosynthesis were enhanced by the overexpression of ***,the chang7-2 and PH4CV transgenic lines may be useful for future genetic improvements of maize hybrids to increase drought tolerance.

关键词： inbred maize lines drought stress ZmVPP1 photosynthesis

Experimental investigation on aerodynamic and noise characteristics of Fenestron

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Aeronautics 2023年第12期36卷 88-101页

作者： Bo wang wei zhang Fei wang Qijun ZHAO Chenkai cao Yuan GAO National Key Laboratory of Rotorcraft Aeromechanics Nanjing University of Aeronautics and AstronauticsNanjing 210016China China Helicopter Research and Development Institute Jingdezhen 333001China

It is difficult to simulate the strong interference and serious flow separation of Fenestron by the CFD method based on the widely used RANS equation,and the detailed experimental data,which could be used to validate the aerodynamic and noise numerical methods,is *** experimental investigation on the aerodynamic and noise characteristics of Fenestron is carried *** view of the complex internal flow field in duct and the relative motion between the stationary duct and the rotating rotor,a comprehensive aerodynamics and pressure measurement scheme is designed based on the bottom support *** this measurement scheme,the thrust generated by the rotating rotor can be measured by the rotating shaft balance,the thrusts from Fenestron are measured by the external balance and the pressures on duct inner wall are monitored by a pressure measuring *** fully capture the noise directionality of Fenestron,a series of noise observers located at an arc array are *** terms of the Fenestron test models,the baseline model,the performance improvement model based on the high-performance tail rotor and the noise reduction model based on the non-uniform blade distribution are designed *** the designed measurement scheme,aerodynamic forces and pressure distributions and noise were measured for the three different Fenestron *** results show that the aerodynamic thrusts of the tail rotor and duct increase greatly and the noise increases slightly for the performance improvement model because of the larger *** rotor aerodynamic performance of the noise reduction model is reduced,but the modulation effect of the tail rotor improves the forces of the *** noise radiated by the noise reduction model is reduced and a good noise reduction result is obtained in frequency domain.

关键词： Helicopter Fenestron Aeroacoustic wind tunnel Noise reduction Non-uniform rotor

A readily monitored and controllable hydrothermal system for the facile,cost-effective transformation of FGD gypsum to calcium sulfate hemihydrate whiskers

在线全文

学校读者我要写书评

暂无评论

Particuology 2021年第1期19卷 173-180页

作者： Bolun cao Xiao wang Xiaoting zhang Biao Jin Zhuoyue Xu Xueping liu wei zhang liushuan yang College of Materials Science and Engineering Zhengzhou UniversityZhengzhou 410001China School of Materials and Chemical Engineering Henan University of Urban ConstructionPingdingshan 467036China Zhengzhou Key Laboratory of Water Resource and Environment Zhengzhou450001China

The controllable transformation of flue gas desulfurization(FGD)gypsum to calcium sulfate hemihydrate(HH)whiskers under facile,readily monitored,and cost-effective hydrothermal conditions could play a vital role in the preparation of high quality HH whiskers and improve our understanding of the transformation *** work assessed the conversion of FGD gypsum to HH whiskers in 5×10^(-4)mol/L H_(2)SO_(4)and 1.5 wt%CuCl_(2)at 120℃while determining the effects of temperature as well as H_(2)SO_(4)and CuCl_(2)concentrations on transformation *** preparation of HH whiskers was found to involve a solution-mediated transformation from the dihydrate(DH)to theα-*** transition was determined to proceed via a dissolution crystallization mechanism,the rate of which was controlled by nucleation and growth of the HH *** autocatalytic kinetic model was established based on variations in the HH whiskers mole fraction over time,and this model accurately fit the experimental data with R2=*** the temperature or H_(2)SO_(4)concentration accelerated the transformation by modifying the super-saturation and water activity in the reaction solution,while increasing the CuCl_(2)concentration had the opposite *** hydrothermal conditions had an important effect on the transformation from FGD gypsum to HH whiskers.

关键词： FGD gypsum Whisker Hydrothermal condition Transformation process Kinetic

Chemical screen identifies a geroprotective role of quercetin in premature aging

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Protein & Cell 2019年第6期10卷 417-435页

作者： lingling Geng Zunpeng liu weiqi zhang wei li Zeming Wu wei wang Ruotong Ren Yao Su Peichang wang liang Sun Zhenyu ju Piu Chan Moshi Song jing Qu Guang-Hui liu Advaneed Innovation Center for Human Brain Protection National Clinical Research Center for Geriatric Disorders Xuanwu Hospital of Capital Medical University Beijing 100053 China National Laboratory of Biomacromolecules CAS Center for Excellenee in Biomacromolecules Institute of Biophysics Chinese Academy of Sciences Beijing 100101 China State Key Laboratory of Stem Cell and Reproductive Biology Institute of Zoology Chinese Academy of Sciences Beijing 100101 China State Key Laboratory of Membrane Biology Institute of Zoology Chinese Academy of Sciences Beijing 100101 China University of Chinese Academy of Sciences Beijing 100049 China Institute of Stem cell and Regeneration Chinese Academy of Sciences Beijing 100101 China Key Laboratory of Regenerative Medicine of Ministry of Education Institute of Aging and Regenerative Medicine Jinan University Guangzhou 510632 China The MOH Key Laboratory of Geriatrics Beijing Hospital National Center of Gerontology Beijing 100730 China

Aging increases the risk of various diseases. The main goal of aging research is to find therapies that attenuate aging and alleviate aging-related diseases. In this study, we screened a natural product library for geroprotective compounds using Werner syndrome (WS) human mesenchymal stem cells (hMSCs), a premature aging model that we recently established. Ten candidate compounds were identified and quercetin was investigated in detail due to its leading effects. Mechanistic studies revealed that quercetin alleviated senescence via the enhancement of cell proliferation and restoration of heterochromatin architecture in WS hMSCs. RNA-sequencing analysis revealed the transcriptional commonalities and differences in the geroprotective effects by quercetin and Vitamin C. Besides WS hMSCs, quercetin also attenuated cellular senescence in Hutchinson-Gilford progeria syndrome (HGPS) and physiological-aging hMSCs. Taken together, our study identifies quercetin as a geroprotective agent against accelerated and natural aging in hMSCs, providing a potential therapeutic intervention for treating age-associated disorders.

关键词： Quercetin Stem cell Aging Werner syndrome Hutchinson-Gilford progeria syndrome

Comparison of microstructure and property of high chromium bearing steel with and without nitrogen addition

在线全文

学校读者我要写书评

暂无评论

Journal of Iron and Steel Research International 2017年第2期24卷 206-213页

作者： Hai-feng Xu Feng Yu chang wang Wan-li zhang Jian li Wen-quan cao Center for Fuel Cell Innovation State Key Laboratory of Material Processing and Die & Mould TechnologySchool of Materials Science and EngineeringHuazhong University of Science and Technology Special Steel Institute Central Iron and Steel Research Institute

Microstructure and property of bearing steel with and without nitrogen addition were investigated by microstructural observation and hardness measurement after different heat treatment processing. Based on the microstructural observation of both 9Cr18 steel and X90N steel, it was found that nitrogen addition could effectively reduce the amount and size of coarse carbides and also refine the original austenite grain size. Due to addition of nitrogen, more austenite phase was found in X90N steel than in 9Cr18 steel. The retained austenite of X90N steel after quenching at 1050℃ could be reduced from about 60% to about 7 9% by cold treatment at -73℃ and subsequent tempering, and thus finally increased the hardness up to 60 HRC after low temperature tempering and to 63 HRC after high temperature tempering. Furthermore, both the wear and corrosion resistance of X90N steel were found much more superior than those of 9Cr18 steel, which was attributed to the addition of nitrogen. It was proposed at last that nitrogen alloying into the high chromium bearing steel was a promising way not only to refine the size of both carbides and austenite, but also to achieve high hardness, high wear property and improved corrosion resistance of the stainless bearing steel.

关键词： Nitrogen addition High temperature tempering High hardness Austenite grain size Carbide Wear resistance High chromium bearing steel

Scalable fabrication and active site identification of MOF shell-derived nitrogen-doped carbon hollow frameworks for oxygen reduction

在线全文

学校读者我要写书评

暂无评论

Journal of Materials Science & Technology 2021年第7期66卷 186-192页

作者： Jiashen Meng Ziang liu Xiong liu wei yang lianzhou wang Yan li Yuan-Cheng cao Xingcai zhang liqiang Mai State Key Laboratory of Advanced Technology for Materials Synthesis and Processing Wuhan University of TechnologyWuhan430070China Nanomaterials Centre School of Chemical Engineering and Australian Institute for Bioengineering and NanotechnologyThe University of QueenslandSt LuciaQLD4072Australia Shenzhen Power Supply Col.Ltd. Shenzhen CityChina State Key Laboratory of Advanced Electromagnetic Engineering and Technology School of Electrical and Electronic EngineeringHuazhong University of Science and TechnologyWuhan430074China John A.Paulson School of Engineering and Applied Sciences Harvard UniversityCambridgeMA02138United States

Nitrogen-doped carbon materials as promising oxygen reduction reaction(ORR) electrocatalysts attract great interest in fuel cells and metal-air batteries because of their relatively high activity, high surface area, high conductivity and low cost. To maximize their catalytic efficiency, rational design of efficient electrocatalysts with rich exposed active sites is highly desired. Besides, due to the complexity of nitrogen species, the identification of active nitrogen sites for ORR remains challenging. Herein, we develop a facile and scalable template method to construct high-concentration nitrogen-doped carbon hollow frameworks(NC), and reveal the effect of different nitrogen species on theirORRactivity on basis of experimental analysis and theoretical calculations. The formation mechanism is clearly revealed, including low-pressure vapor superassembly of thin zeolitic imidazolate framework(ZIF-8) shell on ZnO templates,in situ carbonization and template removal. The obtained NC-800 displays better ORR activity compared with other NC-700 and NC-900 samples. Our results indicate that the superior ORR activity of NC-800 is mainly attributed to its content balance of three nitrogen species. The graphitic N and pyrrolic N sites are responsible for lowering the working function, while the pyridinic N and pyrrolic N sites as possible active sites are beneficial for increasing the density of states.

关键词： MOF shell Nitrogen-doped carbon Hollow framework Oxygen reduction Active nitrogen sites

Subtotal colonic bypass plus colostomy with antiperistaltic cecoproctostomy for the treatment of slow transit constipation in an aged population:A retrospective control study

在线全文

学校读者我要写书评

暂无评论

World Journal of Gastroenterology 2018年第23期24卷 2491-2500页

作者： yang yang Yong-li cao Wen-Hang wang Yuan-Yao zhang Nan Zhao Dong wei Institute of Anal-Colorectal Surgery No.150 Central Hospital of PLA

AIM To compare the efficacy,improved quality of life,and prognosis in patients undergoing either subtotal colonic bypass with antiperistaltic cecoproctostomy(SCBAC) or subtotal colonic bypass plus colostomy with antiperistaltic cecoproctostomy(SCBCAC) for the treatment of slow transit *** Between October 2010 and October 2014,aged patients with slow transit constipation who were hospitalized and underwent laparoscopic surgery in our institute weredivided into two groups: the bypass group,15 patients underwent SCBAC,and the bypass plus colostomy group,14 patients underwent SCBCAC. The following preoperative and postoperative clinical data were collected: gender,age,body mass index,operative time,first flatus time,length of hospital stay,bowel movements(BMs),Wexner fecal incontinence scale,Wexner constipation scale(WCS),gastrointestinal quality of life index(GIQli),numerical rating scale for pain intensity(NRS),abdominal bloating score(ABS),and ClavienDindo classification of surgical complications(CD) before surgery and at 3,6,12,and 24 mo after *** All patients successfully underwent laparoscopic surgery without open surgery conversion or surgeryrelated death. The operative time and blood loss were significantly less in the bypass group than in the bypass plus colostomy group(P = 0.007). No significant differences were observed in first flatus time,length of hospital stay,or complications with CD > 1 between the two groups. No patients had fecal incontinence after surgery. At 3,6,and 12 mo after surgery,the number of BMs was significantly less in the bypass plus colostomy group than in the bypass group. The parameters at 3,6,12,and 24 mo after surgery in both groups significantly improved compared with the preoperative conditions(P li,NRS,and ABS significantly improved in the bypass plus col

关键词： Subtotal colonic bypass plus colostomy with antiperistaltic cecoproctostomy Subtotal colonic bypass with antiperistaltic cecoproctostomy Minimally invasive surgery for treatment of constipation Clinical efficacy Slow transit constipation in an aged population