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   732篇
  免费   51篇
耳鼻咽喉   3篇
儿科学   36篇
妇产科学   19篇
基础医学   161篇
口腔科学   10篇
临床医学   77篇
内科学   107篇
皮肤病学   4篇
神经病学   116篇
特种医学   42篇
外科学   83篇
综合类   7篇
预防医学   29篇
眼科学   10篇
药学   34篇
肿瘤学   45篇
  2021年   18篇
  2020年   6篇
  2019年   11篇
  2018年   10篇
  2017年   10篇
  2016年   17篇
  2015年   18篇
  2014年   19篇
  2013年   27篇
  2012年   45篇
  2011年   54篇
  2010年   25篇
  2009年   24篇
  2008年   36篇
  2007年   43篇
  2006年   22篇
  2005年   19篇
  2004年   33篇
  2003年   34篇
  2002年   32篇
  2001年   9篇
  2000年   14篇
  1999年   12篇
  1998年   6篇
  1997年   9篇
  1996年   4篇
  1994年   4篇
  1993年   6篇
  1992年   15篇
  1991年   18篇
  1990年   7篇
  1989年   7篇
  1988年   11篇
  1987年   7篇
  1986年   8篇
  1985年   10篇
  1984年   14篇
  1983年   5篇
  1981年   5篇
  1980年   7篇
  1979年   9篇
  1978年   7篇
  1977年   7篇
  1976年   6篇
  1975年   6篇
  1974年   9篇
  1973年   12篇
  1972年   14篇
  1970年   6篇
  1967年   3篇
排序方式: 共有783条查询结果,搜索用时 16 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.
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   
5.
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   
6.
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   
7.
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   
8.
Previous in vitro studies have shown that ethanol increased de novo triglyceride synthesis in the rat pancreas. The present study extends these observations on the effects of ethanol on pancreatic lipid metabolism. Ethanol significantly stimulated [1-14C]acetate incorporation into pancreatic lipids at concentrations as low as 0.068 mM, as well as at 3.4 and 34 mM. This suggests that known metabolic pathways of ethanol oxidation are not involved in these changes. Ethanol also stimulated the incorporation of [1-14C]oleate into pancreatic triglyceride and cholesteryl ester, but not into phospholipids. These changes were less marked than those obtained with [1-14C]acetate. Furthermore, incorporation of [1-14C]palmitate into pancreatic lipid was affected even less by ethanol. Thus, ethanol-induced changes in pancreatic lipid metabolism are unlikely to be due to fatty acid esterification alone.  相似文献   
9.
An enzyme immunoassay (EIA) for serum antibodies to human immunodeficiency virus type 1 (HIV-1), based on the synthetic pentadecapeptide SGKLICT-TAVPWNAS, a segment of the transmembrane glycoprotein (gp41) of the virus, was developed and tested for sensitivity and specificity. Sera of 152 individuals at various stages of HIV-1 infection, including two prospectively and six retrospectively studied patients exposed to HIV-1 but seronegative on initial testing in whole-virus EIA and immunoblotting, were screened with the gp41 peptide antibody EIA. The reference population consisted of 1,000 healthy HIV-1 antibody-negative blood donors. In addition, five individuals with antibodies to HIV-2 were studied. Antibodies to the synthetic peptide were detected in 100% of those with asymptomatic infection. Only one patient with LAS failed to react in the peptide EIA. Patients with HIV-2 infection did not react in this test. The peptide antibodies appeared rapidly after infection, were detectable at the time when seroconversion was observed by immunoblotting, and preceded reactivity in whole-virus EIA. Sera of seven patients with verified HIV-1 infection did not react with gp41 in immunoblotting, although antibodies were readily detectable in the gp41 peptide EIA.  相似文献   
10.
BACKGROUND: The natural history of genital human papillomavirus infection is well known, but nearly nothing is known about the outcome of oral HPV-infection. OBJECTIVES AND STUDY DESIGN: To study natural history of oral HPV in spouses during the follow-up 331 women (mean 25.5+/-3.4 years) and 131 men (mean 28.8+/-5.0 years) were recruited from maternity unit. Scrapings from healthy oral mucosa of spouses at baseline, 2, 6, 12 and 24 months and genital samples were taken for HPV testing. HPV DNA was detected by nested PCR and confirmed by hybridization using a cocktail of 12 high-risk (HR) oligoprobes. RESULTS: The detection rate of HR HPVs varied from 15% to 27%. Baseline oral HPV status between the spouses was closely related (odds ratio 4.3; 95% confidence interval 1.6-12.0; P=0.006). Persistent oral infection in one spouse was a significant risk factor (odds ratio 10.0; 95% confidence interval 1.5-68.7; P=0.005) for oral HR HPV persistence in the other partner. Cumulative incidence of new HR HPV infections was identical in both spouses, while men seemed to clear their infection more rapidly. In univariate survival analysis, the partner's oral or genital HPV status, oral sex habits or age did not predict clearance or acquisition of oral HR HPV. CONCLUSION: Natural history of HPV infection in oral mucosa mimics that of genital HPV infection. Oral sex had no association to oral HPV infection, but a persistent oral HPV infection of the spouse increased the risk of persistent oral HPV infection 10-fold in the other spouse.  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