检索结果-南通市图书馆

Poly(lactic acid)-aspirin microspheres prepared via the traditional and improved solvent evaporation methods and its application performances

在线全文

学校读者我要写书评

暂无评论

中国化学工程学报:英文版 2023年第8期60卷 194-204页

作者： Xiaolin Pan Mengyuan Gao Yun Wang Yanping He Tian si Yanlin Sun School of Chemical Engineering Kunming University of Science and TechnologyKunming 650504China

Drug-loaded microspheres are significant for the development of modern pharmaceutical products. It is well known that the taken of aspirin for long-term increases the risk of serious gastrointestinal complications, therefore a controllable delivery of aspirin is of importance to lighten those side effects. In this work, poly(lactic acid)(PLA) was chosen as the carrier to prepare PLA-aspirin microspheres by using the traditional and the improved solvent evaporation methods. It was found that no matter which experimental condition was, the encapsulation efficiency of aspirin was higher by using the improved method than that of the traditional method. Specifically, when the concentration of polyvinyl alcohol = 1%(mass),the polymer concentration = 1:20, the oil/water rate = 1:2.5, PLA-aspirin microspheres were obtained via the improved method with a high yield of 82.83%(mass) and an encapsulation efficiency of 44.09%. PLAaspirin microspheres were then prepared continuously using the improved method, which further enhanced the encapsulation efficiency to 54.56%. Approximate 85% aspirin released from microspheres within 7 days. Obvious degradation which was represented by reduction on hardness was observed by soaking microspheres in PBS for 60 days. This work is of interest because it provides a continuous route to prepare PLA-aspirin microspheres continuously with a high drug encapsulation efficiency.

关键词： Aspirin Degradation Foam-transfer Microspheres Poly(lactic acid) Slow-release

Study on compound Duzhong Jiangu granule in the treatment of knee osteoarthritis based on transcriptome analysis strategy

在线全文

学校读者我要写书评

暂无评论

TMR Modern Herbal Medicine 2024年第1期7卷 34-42页

作者： si-Cong Li Jun-Bo Zou Wu-Lin Kang Pu-Wei Yuan The First Clinical College of Medicine Affiliated Hospital of Shaanxi University of Chinese MedicineXianyang 712000China College of Pharmacy Shaanxi University of Chinese MedicineXianyang 712000China

Duzhong Jiangu Granule in the treatment of primary osteoarthritis(POA)model of postmenopausal kidney deficiency type in Hartley female guinea pigs after ovariectomy,and the correlation between gene expression of bone marrow tissue,cartilage tissue,and knee ***:383-months-old Hartley female guinea pigs after one week of adaptive feeding were weighed about 400 g±20 g,numbered,and sorted by ear *** of them were selected as normal groups by looking up random number *** remainder were removed from the bilateral ovaries to construct the postmenopausal kidney deficiency model,and castrated guinea pigs were used to construct the postmenopausal kidney deficiency POA *** the modeling cycle,a guinea pig from the blank group and a guinea pig from the model group were sacrificed and the right knee was *** model was established and the experiments *** were five guinea pigs in the blank group,and the remaining model guinea pigs were randomly divided into model control group,high-dose group of compound Duzhong Jiangu granules,middle-dose group of compound Duzhong Jiangu granules,low-dose group of compound Duzhong Jiangu granules and design group,with 5 guinea pigs in each *** and model groups were given a cellulose sodium solution by *** guinea pigs were sacrificed after 30 days of intragastric *** left knee cartilage and bone marrow of the blank group,model group,middle dose group,and high dose group of compound Duzhong Jiangu granule were collected and applied to transcriptome sequencing,and the sequencing data were analyzed,including differential gene expression analysis,functional enrichment analysis of database established by Gene Ontology federation(GO)and Kyoto Encyclopedia of Gene and Genome(KEGG)pathway enrichment *** complete specimens of the right knee joint were collected,and the morphological changes of the cartilage of the right knee joint in each group were observed by

关键词： knee osteoarthritis transcriptome sequencing compound Duzhong Jiangu granules micro-CT

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

瘦素及其受体在牦牛附睾的时空表达特性

农业生物技术学报 2024年第2期32卷 334-343页

作者：王晓艳崔燕余四九马睿何俊峰张虔龙敏甘肃农业大学动物医学院甘肃省牛羊胚胎工程技术研究中心

瘦素(leptin)及瘦素受体(leptin receptor, LEPR)在雄性动物生殖调控中发挥重要作用。为探究Leptin及LEPR在性成熟前后牦牛(Bos grunniens)附睾头、体、尾中的分布特点及表达动态，本研究采集性成熟前(幼年)及性成熟后(成年,老年)牦牛... 详细信息

瘦素(leptin)及瘦素受体(leptin receptor, LEPR)在雄性动物生殖调控中发挥重要作用。为探究Leptin及LEPR在性成熟前后牦牛(Bos grunniens)附睾头、体、尾中的分布特点及表达动态，本研究采集性成熟前(幼年)及性成熟后(成年,老年)牦牛附睾不同部位(头,体,尾)，利用qPCR、Western blot和免疫组织化学染色方法检测Leptin及LEPR在不同年龄牦牛附睾头、体、尾中的分布及表达水平。免疫组化结果显示，Leptin和LEPR主要表达在附睾上皮、基底细胞和平滑肌细胞，其中附睾上皮呈强阳性表达；q PCR结果显示，Leptin及LEPR在幼年牦牛附睾头、体和尾的基因表达量显著高于成年和老年(P0.05);Western blot结果显示，Leptin及LEPR蛋白在不同年龄牦牛附睾中均有表达，其表达量在幼年组最高，从幼年、成年及老年，依次呈递减趋势，且各年龄之间差异显著(P0.05);Leptin及LEPR蛋白在成年和老年附睾中的表达量为附睾尾>附睾头>附睾体，且各部位之间差异显著(P<0.05)。结果表明，牦牛性成熟前后附睾中的Leptin及LEPR表达量发生显著变化，并且性成熟后维持在一定水平持续表达至老年，在附睾不同区段的表达也存在差异，附睾尾表达相对最高，说明尾部环境具有较高的Leptin浓度。Leptin及LEPR在牦牛附睾中的时空表达差异提示二者对于牦牛精子的成熟、存储和能量保存方面具有重要意义，本研究为探究高原环境下雄性牦牛的生殖调控机制提供研究资料。

关键词：牦牛附睾瘦素(leptin) 瘦素受体(LEPR)

Effect of Age and Sex on Stroke Mortality of young and Middle-aged Adults in China,2002–2019,and Predictions to 2030

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Biomedical and Environmental Sciences 2023年第4期36卷 305-312页

作者： ZHAI Yi si Xiang WANG Wen Zhi ZHAO Wen Hua China National Clinical Research Center for Neurological Diseases Beijing Tiantan HospitalCapital Medical UniversityBeijing 100070China Division of Non-communicable Disease and Ageing Health Management Chinese Center for Disease Control and PreventionBeijing 102206China Beijing Neurosurgical Institute Capital Medical UniversityBeijing 100070China National Institute for Nutrition and Health Chinese Center for Disease Control and PreventionBeijing 100050China

Objective This study aimed to examine the trends in stroke mortality among young and middle-aged adults in *** Data were obtained from the China national vital registration *** changes in mortality were assessed by Joinpoint ***-period-cohort analysis was used to explain the reasons for the *** mortality and counts were predicted by the Bayesian age-period-cohort *** Between 2002 and 2019,a total of 6,253,951 stroke mortality in young and middle-aged adults were *** age-adjusted mortality rates(AAMRs)of women showed a downward *** annual percent changes(APC)were-3.5%(-5.2%,-1.7%)for urban women and-2.8%(-3.7%,-1.9%)for rural *** contrast,the AAMRs per 100,000 for rural men aged 25–44 years continued to rise from 9.40 to *** AAMRS for urban men aged 25–44 years and urban and rural men aged 45–64years did not change *** 2020 and 2030,the projected stroke deaths are 1,423,584 in men and 401,712 in *** significant sex and age disparities in the trends of stroke mortality among young and middle-aged adults were identified in *** health policy measures are needed to address the burden of stroke in the young generation,especially for rural men,with a focus on the prevention and management of high risk factors.

关键词： Stroke Mortality young and middle-aged Joinpoint regression Age-period-cohort analysis

Virtual Mold Technique in Thermal Stress Analysis during Casting Process

在线全文

学校读者我要写书评

暂无评论

Journal of Materials Science & Technology 2008年第3期24卷 359-363页

作者： si-young Kwak Jae-Wook Baek Jeong-Ho Nam Jeong-Kil Choi E-Design Center Korea Institute of Industrial Technology Department of Virtual Engineering Korea University of Science & Technology

It is important to analyse the casting product and the mold at the same time considering thermal contraction of the casting and thermal expansion of the mold. The analysis considering contact of the casting and the mold induces the precise prediction of stress distribution and the defect such as hot tearing. But it is difficult to generate FEM mesh for the interface of the casting and the mold. Moreover the mesh for the mold domain spends lots of computational time and memory for the analysis due to a number of meshes. Consequently we proposed the virtual mold technique which only uses mesh of the casting part for thermal stress analysis in casting process. The spring bar element in virtual mold technique is used to consider the contact of the casting and the mold. In general, a volume of the mold is much bigger than that of casting part, so the proposed technique decreases the number of mesh and saves the computational memory and time greatly. In this study, the proposed technique was verified by the comparison with the traditional contact technique on a specimen. And the proposed technique gave satisfactory results.

关键词： Casting process Thermal stress analysis Virtual mold

Impact analysis of casting parts considering shrinkage cavity defect

在线全文

学校读者我要写书评

暂无评论

China Foundry 2011年第1期8卷 112-116页

作者： si-young Kwak Jie Cheng Jeong-Kil Choi Center for e-Design Korea Institute of lndustrial Technology Incheon 406-800 Korea Department of Virtual Engineering School of Engineering Korea University of Science ＆ Technology Daejeon Korea

Shrinkage cavity may be detrimental to mechanical performances of casting *** a consequence,design engineers often use overly large safety factors in many designs due to insufficient understanding of quantitative effects of shrinkage cavity *** this paper,process of Al alloy wheel impact test was computationally analyzed for both the wheel models with and without shrinkage cavity *** on shrinkage cavity data obtained from industrial CT (Computerized Tomography),the shrinkage cavity defects were modeled with SSM (Shape simplification Method),which reconstructs shrinkage cavity defects to hollow spheroid *** the impact simulation was conducted,the results show that under impact test condition,the wheel considering shrinkage cavity defects may fracture while the sound-assumed wheel may not.

关键词：扔收缩洞缺点影响计算分析艾尔合金车轮

Evaluation of early-age strains and stresses in roller-compacted concrete pavement

在线全文

学校读者我要写书评

暂无评论

Journal of Traffic and Transportation Engineering(English Edition) 2022年第1期9卷 93-105页

作者： Tetsya Sok young Kyu Kim Jun young Park Seung Woo Lee Public Infrastructure Department Ministry of Public Works and TransportPhnom Penh 12100Cambodia Institute for Disaster Prevention Gangneung-Wonju National UniversityGangneung-si 25457South Korea Korea Expressway Research Institute Korea Expressway CorporationHwaseong-si 18489South Korea Civil Engineering Department Gangneung-Wonju National UniversityGangneung-si 25457South Korea

In the structural design of a roller-compacted concrete pavement(RCCP), it is crucial to estimate strain and stress developments in the RCCP slab realistically. since the RCCP mix uses less cement and lower amount of water, shrinkage strain and concrete temperature during the hardening stage are expected to be reduced as compared to those of conventional concrete mixture, resulting in a reduction of the concrete early-age deformation and stress developments in the RCCP slab. In this paper, early-age concrete strain and stress developments in RCCP slab subjected to environmental loads were evaluated. A full-scale test section of RCCP under real climatic conditions was monitored. The early-age total strains,stress-independent strains, shrinkage strains, and coefficient of thermal expansion(CTE) of the RCCP were measured and analyzed. Using the results of measured strains, in-situ CTE and shrinkage strain, and temperature, the early-age concrete stress development is computed by incorporating a viscoelastic property of the early-age concrete. The results revealed that the shrinkage strain of the RCCP is quite low as compared to that of conventional concrete. The early-age stress developments in the RCCP slab are strongly governed by the thermal-induced stresses. Shrinkage-induced stresses were quite small and might be negligible in a preliminary estimation of early-age stress developments in the RCCP slab.

关键词： Road engineering Roller-compacted concrete pavement Concrete strain Concrete stress Shrinkage strain Environmental loads

For the sake of longevity:eating less and eating at the right time

在线全文

学校读者我要写书评

暂无评论

signal Transduction and Targeted Therapy 2022年第10期7卷 3616-3617页

作者： Fei Sun si Wang Guang-Hui Liu Beijing Institute for Stem Cell and Regenerative Medicine Beijing 100101China Department of Cell Biology Duke University Medical CenterDurhamNCUSA Advanced Innovation Center for Human Brain Protection and National Clinical Research Center for Geriatric DisordersXuanwu Hospital Capital Medical UniversityBeijing 100053China Aging Translational Medicine Center International Center for Aging and CancerBeijing Municipal Geriatric Medical Research CenterXuanwu HospitalCapital Medical UniversityBeijing 100053China The Fifth People’s Hospital of Chongqing Chongqing 400062China State Key Laboratory of Membrane Biology Institute of ZoologyChinese Academy of SciencesBeijing 100101China University of Chinese Academy of Sciences Beijing 100049China

In a recent issue of Science,Acosta-Rodriguez et *** a feeding paradigm to maximize the effects of caloric restriction(CR)on *** feeding with the circadian rhythm and imposing>12-hour fasting daily on caloric-restricted animals can optimally extend *** embracing the projection of our life expectancy in the last 100~150 years,we are facing aging,an all-new challenge in human ***-associated diseases have gradually replaced communicable diseases,becoming the top cause of death *** increasing social and medical burdens call for not only novel therapies for chronic diseases but also early interventions that mitigate the progression of aging and extend life and health spans.

关键词： life aging globally

High-entropy alloys for accessing hydrogen economy via sustainable production of fuels and direct application in fuel cells

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

Rare Metals 2023年第11期42卷 3553-3569页

作者： Qi-Yang Cheng Meng-Fan Wang Jia-Jie Ni Yan-Zheng He Hao-Qing Ji si-si Liu Tao Qian Cheng-Lin Yan School of Chemistry and Chemical Engineering Nantong UniversityNantong226019China Collaborative Innovation Center of Suzhou Nano Science and Technology College of EnergySoochow UniversitySuzhou215006China Light Industry Institute of Electrochemical Power Sources Suzhou 215600China

Heavy consumption of fossil fuels has raised concerns over the climate change and energy security in the past *** this review,hydrogen economy,as a clean and sustainable energy system,is receiving great *** success of future hydrogen economy strongly depends on the storage of renewable energy in hydrogen and hydrogen-rich chemicals through electrolyzers and conversion back to electricity via fuel *** are at the heart of these critical technologies and great efforts have been devoted to preparing highly efficient ***-entropy alloys(HEAs),with their unique structural characteristics and intrinsic properties,have evolved to be one of the most popular catalysts for energy-related applications,especially those associated with hydrogen ***,recent advances regarding HEAs-based hydrogen economy are comprehensively *** is paid to the discussion of emerged HEAs as a new class of materials in hydrogen energy cycle,carbon-based hydrogen energy cycle,and nitrogen-based hydrogen energy cycle,covering the sustainable electrochemical synthesis of hydrogen and hydrogen-rich fuels and their direct application in fuel *** on this overview,the challenges and promising directions are proposed to guide the development of HEAs research,aiming to achieve significant progress for further accessing hydrogen economy.

关键词： High-entropy alloys(HEAs) Hydrogen economy Electrocatalysis Fuel cell Energy conversion