首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   154篇
  免费   14篇
儿科学   5篇
妇产科学   7篇
基础医学   17篇
口腔科学   10篇
临床医学   61篇
内科学   15篇
神经病学   6篇
特种医学   18篇
外科学   6篇
综合类   1篇
预防医学   11篇
药学   6篇
中国医学   1篇
肿瘤学   4篇
  2022年   1篇
  2021年   2篇
  2020年   1篇
  2018年   2篇
  2017年   6篇
  2016年   6篇
  2015年   10篇
  2014年   5篇
  2013年   5篇
  2012年   10篇
  2011年   5篇
  2010年   6篇
  2009年   7篇
  2008年   3篇
  2007年   3篇
  2006年   7篇
  2005年   4篇
  2004年   3篇
  2003年   3篇
  2002年   4篇
  2001年   4篇
  1999年   6篇
  1998年   8篇
  1997年   7篇
  1996年   10篇
  1995年   6篇
  1994年   1篇
  1991年   3篇
  1990年   3篇
  1988年   7篇
  1987年   7篇
  1986年   4篇
  1985年   1篇
  1984年   1篇
  1982年   2篇
  1981年   3篇
  1977年   1篇
  1975年   1篇
排序方式: 共有168条查询结果,搜索用时 15 毫秒
1.
2.
In a prospective, randomized study of insemination with donor semen, intracervical insemination by straw was compared with insemination using a cervical cap with an intracervical reservoir. A total of 91 patients completed 486 treatment cycles. There were no significant differences in age, parity, indication for insemination by donor, or method of cycle monitoring between women who became pregnant and those who did not conceive with either insemination method. In 236 standard intracervical insemination cycles, 14 patients became pregnant (5.9% per cycle), whereas 38 patients conceived in 250 cervical cap cycles (15.2% per cycle). Both the crude pregnancy rates and the cumulative pregnancy rates calculated by the Kaplan-Meier life-table method were significantly different (chi(2)-test, P < 0.001, and log-rank test, P < 0.005 respectively). Pregnancy rates in artificial insemination with cryopreserved donor semen may be improved by the use of a cervical cap when compared to cervical insemination by straw. The use of the cervical cap may prolong the exposure of the spermatozoa to the cervical mucus and prevent the backflow of semen into the vagina.   相似文献   
3.
Low-artifact intravascular devices: MR imaging evaluation   总被引:2,自引:0,他引:2  
Flow-phantom magnetic resonance (MR) imaging, with use of both spin-echo (SE) and gradient-echo (GRE) techniques at 1.5 T, was performed on the percutaneous Greenfield (beta-III titanium alloy [TMA wire]), Amplatz (MP32-N alloy), and Simon nitinol filters and TMA wire facsimiles of the bird's nest, Gunther, new retrievable, and Amplatz vena caval filters. SE imaging allowed detection of thrombi as small as 5 X 5 mm trapped within the percutaneous Greenfield, Simon nitinol, and TMA-wire facsimile filters; with the MP32-N Amplatz filter, a larger volume of thrombus (10 X 20-mm clots) was necessary for clot detection. GRE imaging allowed detection of intraluminal tilting of the percutaneous Greenfield and facsimile Amplatz (TMA-wire) filters. GRE imaging was useful for demonstrating postfilter turbulence due to clots, which was greatest for the Amplatz filter. Imaging of facsimile vascular devices made of tantalum or TMA wire did not cause the severe "black-hole" MR artifacts typical of the stainless-steel devices. SE and GRE imaging were very useful for determining caval patency in two patients with previously placed Mobin-Uddin filters. Noninvasive MR evaluation of blood vessels in the presence of a variety of low-artifact intravascular devices appears feasible.  相似文献   
4.
5.
对发展中国家改善用药的10点建议   总被引:2,自引:0,他引:2  
唐镜波  龚丽娴 《中国药师》2005,8(10):865-868
WHO建议改善药品管理的工作要在国家药物政策保障之下.在许多国家,执行国家药物政策的机制是实施国家基本药物计划,其要点是强调公共领域的药品选择、采购、流通与使用的合理性.不适当的处方使医疗质量降低并导致资源浪费.本文以探讨在国家药物政策范畴内鼓励更合理地使用药品的问题为重点,在已有证据的基础上,详细阐明基本药物计划内容中的合理用药问题.本文评述了在发展中国家改善用药状况的有效策略及最新知识,并为决策者与管理者提出达到改善用药目标的建议.  相似文献   
6.
Background and purpose — In a time when rapid diagnostics are increasingly sought, conventional procedures for detection of microbes causing orthopedic implant-associated infections (OIAI) seem extensive and time-consuming, but how extensive are they? We assessed time to (a) pathogen identification, (b) antibiotic susceptibility patterns, and (c) targeted antibiotic treatment using conventional microbiological diagnostics of OIAI in a consecutive series of patients.Patients and methods — Consecutive patients aged ≥18 years undergoing first revision surgery for acute OIAI, including prosthetic joints, fracture, and osteotomy implants, in 2017–2018 at Akershus University Hospital (Ahus), Norway were included. Information regarding microbiological diagnostics and clinical data was collected retrospectively from the hospital’s diagnostic and clinical databases.Results — 123 patients fulfilled the inclusion criteria. Median time to pathogen identification was 2.5 days and to antibiotic treatment recommendations was 3.5 days. The most common pathogens were S. aureus (52%) and S. epidermidis (15%). Cultures were inconclusive in 11% of the patients. Of the 109 patients with culture-positive results, antibiotic treatment was changed in 66 (61%) patients within a median of 4 days (0–24) after the recommendation was given.Interpretation — Conventional microbiological diagnostics of OIAI is time-consuming, taking days of culturing. Same-day diagnostics would vastly improve treatment efficacy, but is dependent on rapid implementation by clinicians of the treatment recommendations given by the microbiologist.

The majority of orthopedic procedures include the use of implants, which increase the risk of infection due to the reduced number of bacteria needed to establish an infection (Zimmerli et al. 1982). Orthopedic implant-associated infections (OIAI) are infrequent per se, with an overall surgical site infection rate following implant surgery of 3% (Skråmm et al. 2012). However, the number of patients undergoing orthopedic implant surgery is high and increasing (Norwegian National Advisory Unit on Arthroplasty and Hip Fractures 2020).A microbiological diagnosis is vital for providing the best treatment, with regards to both surgical options and providing targeted and narrow-spectrum antimicrobial therapy (Beam and Osmon 2018). Today’s conventional diagnostics include microbiological culturing of 5 biopsies from each infected patient on several different media for at least 5 days dependent on growing and dividing bacteria (Bergh et al. 2011, Osmon et al. 2013). More rapid diagnostic tools are being developed, but with varying degrees of sensitivity and specificity (Bonanzinga et al. 2017, Jun and Jianghua 2018, Aamot et al. 2019).We assessed time to (a) pathogen identification, (b) antibiotic susceptibility patterns, and (c) targeted antibiotic treatment using conventional microbiological diagnostics of OIAI in a consecutive series of patients.  相似文献   
7.
8.
以乙型肝炎病毒为载体的基因治疗研究   总被引:6,自引:1,他引:6  
目的 探讨乙型肝炎病毒(HBV)作为肝靶向性基因治疗载体的可能性。方法 用外源报告基因绿色荧光蛋白(GFP)取代HBV S基因读码框构建重组HBV载体,通过脂质体转染HepG2细胞,荧光显微镜下观察外源基因的表达,半巢式聚合酶链反应(PCR)检测细胞核内HBV 共价闭合环状DNA构型,常规PCR和Southern杂交检测上清液重组病毒DNA。结累 携带外源基因GFP的重组HBV载体能够在肝细胞内表达外源蛋白,此重组载体为复制缺损型,单独转染后不能在肝细胞包装与复制,在缺失包装信号ε的辅助HBV质粒下可被包装成携带外源基因的成熟重组HBV颗粒并分泌到胞外。结论 HBV可被改造成肝靶向性基因治疗载体。  相似文献   
9.
10.
BACKGROUND & AIMS: The functional significance of intestinal hyperplasia stimulated by insulin-like growth factor (IGF)-I is unclear and has not been studied in a model of mucosal atrophy induced by total parenteral nutrition (TPN). The aim of this study was to determine how IGF-I affects intestinal structure and epithelial function in the absence of luminal nutrition caused by TPN. METHODS: Rats were maintained with TPN with or without IGF-I (800 micrograms/day), and jejunal histology and epithelial ion transport were measured after 5 days. In a third TPN group without IGF-I, a short-term dose of IGF-I was added during in vitro flux chamber experiments. RESULTS: Rats given TPN with IGF-I had greater jejunal mucosal weight, greater protein and DNA content, and increased villus height and crypt depth compared with rats given TPN only. TPN increased ionic permeability and ion transport responses to secretory and absorptive agents. IGF-I in vivo reversed most of these changes; IGF-I in vitro enhanced sodium-dependent glucose absorption but had no other effects. CONCLUSIONS: Coinfusion of recombinant human IGF-I with TPN solution stimulates intestinal hyperplasia and attenuates transport changes induced by TPN. The latter effect seems to be primarily associated with the growth state of the epithelium. (Gastroenterology 1996 Dec;111(6):1501-8)  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号