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   11721篇
  免费   1737篇
  国内免费   36篇
耳鼻咽喉   205篇
儿科学   336篇
妇产科学   233篇
基础医学   1849篇
口腔科学   212篇
临床医学   1369篇
内科学   2297篇
皮肤病学   123篇
神经病学   996篇
特种医学   493篇
外国民族医学   1篇
外科学   1505篇
综合类   627篇
一般理论   8篇
预防医学   1457篇
眼科学   172篇
药学   893篇
中国医学   26篇
肿瘤学   692篇
  2021年   127篇
  2020年   113篇
  2019年   186篇
  2018年   242篇
  2017年   168篇
  2016年   148篇
  2015年   188篇
  2014年   246篇
  2013年   368篇
  2012年   561篇
  2011年   567篇
  2010年   302篇
  2009年   287篇
  2008年   486篇
  2007年   480篇
  2006年   474篇
  2005年   461篇
  2004年   467篇
  2003年   453篇
  2002年   420篇
  2001年   398篇
  2000年   466篇
  1999年   386篇
  1998年   223篇
  1997年   148篇
  1996年   155篇
  1995年   157篇
  1994年   152篇
  1993年   128篇
  1992年   290篇
  1991年   308篇
  1990年   259篇
  1989年   300篇
  1988年   243篇
  1987年   268篇
  1986年   237篇
  1985年   248篇
  1984年   222篇
  1983年   190篇
  1982年   160篇
  1981年   108篇
  1980年   82篇
  1979年   175篇
  1978年   125篇
  1977年   117篇
  1976年   102篇
  1974年   102篇
  1973年   98篇
  1972年   80篇
  1971年   73篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
OBJECTIVE: To determine how adults with myelomeningocoele who develop the Chiari/hydrosyringomyelia complex present, and to determine if surgical intervention influences outcome in these patients. METHODS: A chart review of the 220 patients who attend a clinic for adults with spina bifida and hydrocephalus (CASBAH), and follow-up of the five cases with myelomeningocoele who had surgical intervention for associated symptomatic Chiari/hydrosyringomyelia complex. RESULTS: Bilateral upper limb weakness and wasting were the commonest presenting symptoms (four patients). Sensory disturbance (three patients) was also common, dysphagia (one) and ataxia (one) occurring less often. The median time to surgical intervention was 36 months. Two patients had a shunting procedure performed in isolation, two foramen magnum decompression in addition to a shunting procedure and one a foramen magnum decompression. Surgical intervention did not completely reverse problems attributed to the Chiari/hydrosyringomyelia complex in any of the cases. One patient died post-operatively. Of the four who survived one had some improvement in function post-operatively, two remained static and one had further mild deterioration. CONCLUSION: All adults with myelomeningocoele should be questioned about changes in upper limb function for early detection of Chiari/hydrosyringomyelia complex. Our results suggest that early intervention is needed if further deterioration is to be avoided, and to improve the chances of neurological and functional recovery.  相似文献   
992.
993.
994.
995.
Since the initial case report in 1958, 69 cases of catamenial pneumothorax have appeared in English-language literature. Despite the extensive case material, the pathogenesis has not been fully elucidated. Herein an additional case is reported utilizing computed tomography (CT) to search for intrathoracic endometrial implants. The four major pathogenetic theories include passage of air from the genital tract via diaphragmatic defects, spontaneous rupture of subpleural blebs, intrathoracic endometriosis, and prostaglandin-induced bronchiolar constriction resulting in alveolar rupture. Evidence for and against each theory is presented.  相似文献   
996.
A patient with a debilitating disease, such as epidermolysis bullosa, is a challenge to the dentist wishing to provide optimal and comprehensive dental treatment. While tissue sloughing and bullae formation during treatment cannot be eliminated, the previously outlined protocol can limit the severity of it.
Medical assessment of these patients is mandatory to determine their overall health status. If indicated, a combination medical and dental procedure can be performed under general anesthesia, thereby limiting the number of stressful operations a patient may have to undergo.
Triannual dental examinations and continual re-evaluation are necessary to promote continued dental health and recognition of early pathosis. Aggressive preventive measures are necessary to ensure the patient's future dental needs are minimal.  相似文献   
997.
Purification of a bactericidal protein (BP) from the cytoplasmic granules of normal human polymorphonuclear leukocytes (PMN) with activity against Pseudomonas aeruginosa is described. Bactericidal activity from acid extracts of a mixed granule population was purified 175-fold by a two-step chromatographic procedure. The first step, dye-ligand affinity chromatography with Matrex-Gel Orange A, was followed by cation-exchange chromatography with Bio-Rex 70 resin, and this combination routinely gave a yield near 80%. Only one peak of bactericidal activity against P. aeruginosa type I was found after each chromatographic step. Characterization of BP showed a single band with an apparent molecular weight of 55,000 by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Purified BP was most active against the six strains of P. aeruginosa tested and against Escherichia coli B (a deep rough mutant). Purified BP killed 5 X 10(6) CFU of P. aeruginosa type I per ml at a concentration of 60 to 80 ng/ml. Proteus mirabilis and Staphylococcus aureus were both resistant to the bactericidal activity of BP. BP was shown to be glycosylated by periodic acid staining after gel electrophoresis and to have an isoelectric point near 7.5 by chromatofocusing. The amino acid composition of BP is presented.  相似文献   
998.
The quantitative effect of plasmapheresis on concentrations of intravascular solutes is described by a minimal two-compartment model, which allows exit to and entry from a nonplasma body pool of the solute. This novel method is simple and capable of determining endogenous metabolic turnover of physiologically important plasma constituents in both therapeutic and experimental settings. The model was suggested by the therapeutic use of plasmapheresis in hyperlipidemia, and the turnover rates of triglyceride and cholesterol were calculated for one patient treated with chronic plasmapheresis. It is concluded that at least a two-compartment model is necessary to quantitatively describe the effect of plasmapheresis on any substance that undergoes appreciable endogenous turnover (metabolic clearance rate greater than 1.1 times plasmapheresis rate when both rates are in units of volume per time). Calculation of endogenous turnover rate with the use of measurements of the concentration of a solute in plasma before and after plasmapheresis and in the total plasmapheresate and measurement of the volume of plasma removed, volume of plasma substitute infused, and total plasmapheresis time is detailed. This method avoids the use of isotopic labeling experiments. In turn, the endogenous turnover rate may predict the efficacy of therapeutic plasmapheresis.  相似文献   
999.
1000.
Summary A case is reported of the rare association between progressive multifocal leucoencephalopathy and carcinoma. A 66-year-old man underwent a laryngectomy for carcinoma. Four years later he developed a local recurrence. Simultaneously there were behavioural disturbances and a left motor neglect followed by dense hemiplegia and coma. The patient died a further 5 months later. Anergy was demonstrated by skin tests. CT scan showed asymmetrical non-enhancing low-density areas in the hemispheric white matter, brain-stem and cerebellum and neuropathological examination confirmed extensive myelin loss with typical papovavirus inclusions in oligodendrocytes identified by electron microscopy.Presented at the Irish Neurological Association and Danish Neurological Society joint meeting, Cork, 16 May 1985  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