检索结果-南通市图书馆

在线全文

学校读者我要写书评

暂无评论

汽车底盘关键子系统侧翻控制权重研究

高技术通讯 2012年第5期22卷 545-551页

作者：卢少波尚凯李以农郑玲 choiSeungbok 重庆大学机械传动国家重点实验室重庆400044 韩国INHA大学机械工程系智能结构与系统实验室仁川402751

针对汽车底盘关键子系统对侧翻运动影响能力及有效作用区域的差异，综合考虑了车辆运动耦合及轮胎力耦合因素，建立了包含悬架、制动和转向系统的11自由度整车侧翻动力学模型。以主动前轮转向、独立制动及主动悬架等底盘典型控制系统为... 详细信息

针对汽车底盘关键子系统对侧翻运动影响能力及有效作用区域的差异，综合考虑了车辆运动耦合及轮胎力耦合因素，建立了包含悬架、制动和转向系统的11自由度整车侧翻动力学模型。以主动前轮转向、独立制动及主动悬架等底盘典型控制系统为对象，以系统的控制输入为分析变量，选取各系统对车体产生的侧倾修正力矩为权重评价依据，定量地研究了其对侧翻控制的功能权重及有效作用范围。结果表明，这三个控制子系统都可以在不同程度上有效地控制侧翻运动。分析明确了各系统工作的有效工作区域和控制权重，为车辆侧翻控制策略的制定提供了依据。

关键词：侧翻动力学模型控制权重转向制动悬架

Vesicle-bound and free microRNAs in spent cell culture medium and biological fluids

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Advances in Bioscience and Biotechnology 2012年第8期3卷 1091-1095页

作者： Gang Wang Ka-Bik Lai Bonnie Ching-Ha Kwan kai-Ming chow Philip Kam-Tao Li Cheuk-Chun Szeto Department of Medicine & Therapeutics The Chinese University of Hong Kong Hong Kong China

Background: In addition to the control of gene transla- tion intra-cellularly, microRNAs (miRNAs) have been found to exist extracellularly. However, extracellular miRNA identified in previous studies were largely confined to microvesicles. It remains uncertain whether free extracellular miRNA exists. Methods: We quantify a panel of miRNAs (miRNA 200 family, miR-205, and miR-192) in spent culture medium of renal tubular epithelial cells, as well as serum and urine from patients with systemic lupus erythematosus and healthy controls. Microvesicle bound and free miRNA were separated by ultracentrifugation. Results: In spent cell culture medium, we found substantial amount of miR-200a, miR-200b, miR-200c, miR-141, miR-429, miR-205, and miR-192 in microvesicles, as well as the presence of miR-200a, miR-200b, miR-429, miR-205 and miR-192, but not miR-200c or miR-141 as non-vesicle bound free form. In healthy individuals, we found substantial amount of miR-200a, miR-200b, miR-200c, miR-141 and miR-192 in microvesicles from serum and urine, while only miR-141 exists as free form in both serum and urine. There was no significant difference in serum or urinary free miR-141 levels between SLE patients and healthy controls. In SLE patients, urinary free miR-141 level was signifiantly higher than serum. Neither serum nor urinary free miR-141 levels correlated with lupus disease activity. Conclusion: We found miRNA is present extracellularly, both within microvesicles and as free form, in spent cell culture medium, serum and urine. The biological role of extracellular miRNA requires further study.

关键词： Cell Signaling Fibrosis Cytokine

Non-vesicle-bound free microRNAs could enter cells and affect gene expression

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Advances in Bioscience and Biotechnology 2012年第3期3卷 181-185页

作者： Gang Wang Ka-Bik Lai Bonnie Ching-Ha Kwa kai-Ming chow Philip Kam-Tao Li Cheuk-Chun Szeto Department of Medicine & Therapeutics The Chinese University of Hong Kong Hong Kong China

Background: Cell-free microRNAs (miRNAs) exist in body fluid. Previous studies showed that cell-free mi-RNAs are partly bound in microvesicles, and could transfer between cells via fusion with cell membrane. Methods: We quantified the amount of a panel of mi-RNA targets in and outside microvesicles in human proximal tubular epithelial cell (HK2) medium by microarray and real-time quantitative polymerase chain reaction (RT-QPCR). Intercellular miRNA transfer was explored by medium transfer experiments. Results: We identified a portion of cell-free miRNAs that exists as non-vesicle bound, truly naked form. More importantly, these non-vesicle bound free miRNA could transfer between cells and exert biological effects. By miRNA microarray, we showed that the expression of many miRNA targets in HK-2 cells were altered, either up- or down-regulated, after exposure to extrinsic free miRNAs. The miRNA-200 family was the most affected in our model, with a corresponding alteration in the messenger RNA expression of down-stream targets including ZEB1 and vimentin. Conclusion: Our results suggest that free miRNA may serve as an intercellular messenger, a phenomenon that needs further exploration.

关键词： Cell Signaling Fibrosis Cytokine

一种含螺吡喃和肉桂酸酯双光功能基团的光致变色染料的合成与性能

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

高等学校化学学报 2005年第5期26卷 935-938,F009页

作者：申凯华李晓莲崔东熏大连理工大学精细化工国家重点实验室大连116012 庆熙大学高分子工程系

合成了一种含有光致聚合肉桂酸酯基团的新型光致变色螺吡喃染料,研究其与普通螺吡喃染料在不同高分子材料中的光致变色和热退色过程(PMMA和PVCi).通过UV-Vis光谱、NMR谱和IR光谱研究了新型染料中的肉桂酸酯基团的光致聚合过程,考察了其... 详细信息

合成了一种含有光致聚合肉桂酸酯基团的新型光致变色螺吡喃染料,研究其与普通螺吡喃染料在不同高分子材料中的光致变色和热退色过程(PMMA和PVCi).通过UV-Vis光谱、NMR谱和IR光谱研究了新型染料中的肉桂酸酯基团的光致聚合过程,考察了其对螺吡喃结构的光致变色显色体热稳定性的影响.

关键词：肉桂酸酯螺吡喃光致变色

当代世界文化危机、回归传统与中国的儒学复兴运动

在线全文

学校读者我要写书评

暂无评论

文化发展论丛 2017年第1期 44-70页

作者：周启荣美国伊利诺州立大学香槟分校东亚语言文化系、历史系

21世纪无疑是全球史新一章的开始,而揭开这一章序幕的是两个影响全球的历史事件：第一个是＂中国的崛起＂,第二个是＂西方文明的回落＂。这两个事件同样导致中国与西方国家的＂回归传统＂运动。虽然中国与西方国家都要求回到自己的文化... 详细信息

21世纪无疑是全球史新一章的开始,而揭开这一章序幕的是两个影响全球的历史事件：第一个是＂中国的崛起＂,第二个是＂西方文明的回落＂。这两个事件同样导致中国与西方国家的＂回归传统＂运动。虽然中国与西方国家都要求回到自己的文化＂传统＂,但是两者所要回归的＂传统＂差异甚大。当代中国的传统文化复兴运动的对象是历史人文主义的传统文化,尤其是儒家思想与价值。西方希望＂去世俗化＂,要求回到独一神道主义的宗教传统。本文旨在分析在全球的文化危机中,中国与西方如何重新回到建构的＂传统＂中找寻应对时代危机的方法,通过两个过程的比较来探讨当代儒学复兴的全球史意义。中国能够成功地回归儒家传统将为世界提供一个稳定的磐石。

关键词：中国传统文化儒学复兴西方文明危机去世俗化基督教

Sweet food improves chronic stress-induced irritable bowel syndrome-like symptoms in rats

在线全文

学校读者我要写书评

暂无评论

World Journal of Gastroenterology 2014年第9期20卷 2365-2373页

作者： Sang-Gyun Rho Yong Sung Kim Suck Chei choi Moon Young Lee Department of Emergency Medical Services Sunmoon University Chungnam Asan 336-708 South Korea Department of Gastroenterology and Wonkwang Digestive Disease Research Institute Wonkwang University Sanbon Hospital Gyeonggi Gunpo 435-040 South Korea Department of Gastroenterology and Wonkwang Digestive Disease Research Institute School of MedicineWonkwang University Jeonbuk Iksan 570-974 South Korea Department of Physiology and Institute of Wonkwang Medical Science and Wonkwang Digestive Disease Research Institute School of Medicine Wonkwang UniversityJeonbuk Iksan 570-749 South Korea

AIM: To investigate whether palatable sweet foods have a beneficial effect on chronic stress-induced colonic motility and inflammatory cytokines.

关键词： Irritable bowel syndrome Colon Stress Adrenal hormones Cytokines Rat

Enteral nutrition combined with glutamine promotes recovery after ileal pouch-anal anastomosis in rats

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 2018年第5期24卷 583-592页

作者： Yan-Yan Xu An-Qi He Gang Liu kai-Yu Li Jian Liu Tong Liu Department of General Surgery Tianjin Medical University General Hospital

AIM To assess the effect of enteral nutrition(EN) supplemented with glutamine on recovery after ileal pouch-anal anastomosis(IPAA) in rats, to provide an experimental basis for nutritional support in patients with ulcerative colitis(UC) after IPAA. METHODS Male Sprague-Dawley(SD) rats were randomly divided into three groups(n = 8) after IPAA operation using a microsurgical technique. From the third postoperative day, rats in the control group, EN group, and immune nutrition(IN) group were fed standard rat chow, short peptide EN, and short peptide EN combined with glutamine ad libitum, respectively. The rats' general condition was observed throughout the study. Serum levels of total protein(TP), albumin(ALB), prealbumin(PA), and transferrin(TF) were detected on the 30 th postoperative day, using an automatic biochemical analyzer. The ileal pouch mucosa was stained with hematoxylin and eosin(HE), and occludin protein levels were detected by *** The body weight of rats in the EN group(359.20 ± 10.06 g) was significantly higher than that in the control group(344.00 ± 9.66 g)(P 0.05 for all). CONCLUSION EN combined with glutamine may effectively improve nutritional status after IPAA. Our results suggest a benefit of glutamine supplementation in EN for UC patients undergoing IPAA, although human st

关键词： Enteral nutrition Glutamine Ileal pouchanal anastomosis Nutritional status Recovery

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

聚氨酯弹性体的热分解动力学研究

应用化学 2005年第8期22卷 861-864页

作者：袁开军江治李疏芬周允基中国科学技术大学化学物理系合肥230026 香港理工大学屋宇设备工程系

采用热分析技术考察了聚醚型聚氨酯和聚酯型聚氨酯在有氧条件和无氧条件下的热解反应,使用模型拟合法计算了各步反应的活化能E、指前因子A等动力学参数,提出了各步反应的机理函数。结果表明,2种聚氨酯第1阶段分解都受扩散过程控制,此外... 详细信息

采用热分析技术考察了聚醚型聚氨酯和聚酯型聚氨酯在有氧条件和无氧条件下的热解反应,使用模型拟合法计算了各步反应的活化能E、指前因子A等动力学参数,提出了各步反应的机理函数。结果表明,2种聚氨酯第1阶段分解都受扩散过程控制,此外聚酯型聚氨酯比聚醚型聚氨酯的热稳定性高,同时氧气的存在促进了聚氨酯主链上C—C和C—O键的断裂。

关键词：聚醚型聚氨酯聚酯型聚氨酯热分解动力学模型拟合法

2022版国际腹膜透析协会腹膜透析相关性腹膜炎防治指南更新重点内容

在线全文

学校读者我要写书评

暂无评论

中华肾脏病杂志 2022年第10期38卷 938-944页

作者：田娜周启明余学清李锦滔宁夏医科大学总医院肾脏内科银川750004 香港威尔斯亲王医院内科及药物治疗学系、香港中文大学余宇康余雷觉云腹膜透析研究中心中国香港特别行政区999077 广东省人民医院肾内科广州510080

腹膜透析(peritoneal dialysis,PD)相关性腹膜炎(PD-associated peritonitis,PDAP)是PD的严重并发症,防治PDAP对降低患者的发病率和病死率至关重要。近期发布的2022版国际腹膜透析协会(International Society for Peritoneal Dialysis,ISPD)有关PDAP防治指南中,对于难治性腹膜炎(refractory peritonitis)、再发性腹膜炎(recurrent peritonitis)、复发性腹膜炎(relapsing peritonitis)、重现性腹膜炎(repeat peritonitis)、腹膜炎相关导管拔除(peritonitis-associated catheter removal)、腹膜炎相关转血液透析(peritonitis-associated haemodialysis transfer)、腹膜炎相关死亡(peritonitis-associated death)、腹膜炎相关住院(peritonitis-associated hospitalisation)等概念均赋以明确定义,提出了一些新的腹膜炎类型和预后概念,如PD前腹膜炎(pre-PD peritonitis)、肠源性腹膜炎(enteric peritonitis)、导管相关性腹膜炎(catheter-related peritonitis)及腹膜炎的临床治愈(medical cure)。新指南建议PDAP的总体发生风险应低于0.4例次/患者年,每年无腹膜炎患者占比应高于80%。对于PD系统污染的处理、侵入性操作的抗生素预防、PD培训与再评估以及腹膜炎可预防的风险因素如豢养宠物、H2受体拮抗剂等热点问题均在新指南中给予了阐释。经验性抗生素的选择和剂量,及针对特殊病原菌口服N-乙酰半胱氨酸辅助减轻氨基糖苷类耳毒性的新方法也在新指南中进行了介绍。最后,指南对未来腹膜炎防治的研究方向给出了建议。

关键词：腹膜透析腹膜炎指南治疗预防预后