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   591篇
  免费   49篇
耳鼻咽喉   1篇
儿科学   33篇
妇产科学   25篇
基础医学   106篇
口腔科学   15篇
临床医学   107篇
内科学   69篇
神经病学   102篇
特种医学   49篇
外科学   51篇
综合类   5篇
预防医学   19篇
眼科学   10篇
药学   22篇
中国医学   1篇
肿瘤学   25篇
  2021年   12篇
  2019年   6篇
  2018年   7篇
  2017年   8篇
  2016年   13篇
  2015年   20篇
  2014年   11篇
  2013年   16篇
  2012年   25篇
  2011年   32篇
  2010年   15篇
  2009年   15篇
  2008年   11篇
  2007年   21篇
  2006年   15篇
  2005年   10篇
  2004年   21篇
  2003年   19篇
  2002年   28篇
  2001年   12篇
  2000年   12篇
  1999年   18篇
  1998年   12篇
  1997年   14篇
  1996年   13篇
  1995年   7篇
  1994年   4篇
  1993年   4篇
  1992年   14篇
  1991年   21篇
  1990年   9篇
  1989年   7篇
  1988年   17篇
  1987年   11篇
  1986年   12篇
  1985年   11篇
  1984年   14篇
  1983年   5篇
  1982年   4篇
  1981年   8篇
  1980年   7篇
  1979年   9篇
  1978年   7篇
  1977年   8篇
  1976年   6篇
  1975年   7篇
  1974年   9篇
  1973年   12篇
  1972年   14篇
  1970年   6篇
排序方式: 共有640条查询结果,搜索用时 15 毫秒
1.
Three different pathogenic mechanisms are apparent for paraparesis in association with a bacterial infection: a spinal cord compression caused by either an epidural abscess or a vertebral collapse due to spondylitis, an ischaemic spinal cord lesion as a result of septic thromboembolus in abdominal aorta, and a nonspecific, probably immunological, cause in association with reactive polyarthritis. An example of each of these mechanisms is described by means of case histories.  相似文献   
2.
3.
A 15-year-old boy with a terminal deletion of the short arm of chromosome 4 is described. The patient has a mild clinical phenotype that is incompatible with Wolf-Hirschhorn syndrome. Careful neurological examination including CT scan did not show any signs of Huntington disease. The chromosomal breakpoint was analyzed by means of polymorphic DNA probes localized close to the tentative Huntington (HD) locus. The breakage has occurred between D4S43 and D4S90 loci and thus deletes part of the chromosomal candidate regions for the HD locus. © 1992 Wiley-Liss, Inc.  相似文献   
4.
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   
5.
A 17-year-old man developed acute hemiparesis 6 months after a motor cycle accident. In the accident he had a closed trauma on the contralateral side of the head and the neck, with multiple bone fractures. Aortocervical angiography, performed after the infarction, revealed a 2.5 cm long aneurysmatic dilatation in the internal carotid artery, the presumably source of embolic infarction. This and the 24 other cases gathered from the literature support the notion that closed neck trauma may create "false aneurysm" which again may cause neurological deficits.  相似文献   
6.
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   
7.
8.
Summary The effects of microwave hyperthermia (41° and 43° C) on virus multiplication have been exploredin vitro (HSV-1 infected primary rabbit kidney cultures) andin vivo (mice infected with HSV-1 or vaccinia). In vitro the cells were inoculated with HSV-1 and heated to 41° or 43° C either before or after infection. Virus yields were significantly decreased when the cells were exposed to hyperthermia within the first few hours after infection, while hyperthermia was without effect when applied before infection or with several hours delay after infection.In mice inoculated intranasally with HSV-1, mortality due to herpes encephalitis was significantly reduced upon daily exposure to microwave hyperthermia from the day of infection onward.In mice inoculated intravenously with vaccinia, a significant decrease in the number of specific tail lesions was observed if the animals were exposed to microwave hyperthermia within the first three days after infection, while irradiation prior to infection or delayed until several days after infection did not exhibit an appreciable effect.Our data suggest that microwave hyperthermia interferes directly with the virus multiplication cycle bothin vitro andin vivo.With 3 Figures  相似文献   
9.
A three generation family with X linked myotubular myopathy (MTM1) was studied with several polymorphic markers from the distal long arm of the X chromosome. A recombination between the disease gene and four markers (loci DXS52, DXS134, DXS15, F8C) from the Xq28 cluster was detected. A new polymorphic marker (U6.2) defining the locus DXS304 in the Xq27-28 region proximal to the Xq28 cluster did not show any recombination with MTM1. These results suggest the following order of loci in distal Xq: cen-DXS42-DXS105-(DXS304, MTM1)-(DXS52, DXS134, DXS15, F8C)-tel.  相似文献   
10.
Of the families who had received genetic counselling between 1972 and 1981, 791 replied to a questionnaire which covered recall of information, post-counselling reproduction and attitudes towards counselling and prenatal diagnosis. Eighty percent had adequate knowledge of mode of inheritance and 74% of recurrence risk. Knowledge of mode of inheritance was poorest in multifactorial transmission (63%) and knowledge of recurrence risk in X-chromosomal disorders (61%). Forty-five per cent of the families had started a pregnancy after the counselling. 25%). Early lethality of the disorder and feasibility of a prenatal study contributed to positive reproductive decisions. Nine per cent of the children born after the counselling were affected by the disorder in question. The observed risks tended to match well with the expected ones. Sixty-two per cent of the respondents felt that the counselling had had a great or moderate impact on their reproductive plans. Forty-two per cent expressed a wish to hear the counsellor's opinion in addition to the facts. This was more common when the disorder was severe. Although most couples (53%) wished to have a prenatal study, if feasible, and abort an affected foetus, 16% were against abortion in such a case and 31% wished to have the study but were ambiguous about an abortion.  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