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   312247篇
  免费   18895篇
  国内免费   1169篇
耳鼻咽喉   3521篇
儿科学   7764篇
妇产科学   5927篇
基础医学   39658篇
口腔科学   7272篇
临床医学   29834篇
内科学   68357篇
皮肤病学   5046篇
神经病学   30517篇
特种医学   11884篇
外国民族医学   15篇
外科学   47411篇
综合类   2851篇
现状与发展   1篇
一般理论   204篇
预防医学   23379篇
眼科学   7016篇
药学   20577篇
  1篇
中国医学   607篇
肿瘤学   20469篇
  2023年   1835篇
  2022年   2449篇
  2021年   6554篇
  2020年   3778篇
  2019年   6348篇
  2018年   8454篇
  2017年   5888篇
  2016年   6359篇
  2015年   7902篇
  2014年   10601篇
  2013年   14542篇
  2012年   23870篇
  2011年   24663篇
  2010年   13045篇
  2009年   11482篇
  2008年   21537篇
  2007年   22476篇
  2006年   22163篇
  2005年   21739篇
  2004年   20294篇
  2003年   18480篇
  2002年   17652篇
  2001年   3605篇
  2000年   3625篇
  1999年   3109篇
  1998年   3034篇
  1997年   2388篇
  1996年   2093篇
  1995年   1919篇
  1994年   1646篇
  1993年   1612篇
  1992年   1174篇
  1991年   1100篇
  1990年   924篇
  1989年   865篇
  1988年   766篇
  1987年   706篇
  1986年   744篇
  1985年   789篇
  1984年   1037篇
  1983年   871篇
  1982年   1134篇
  1981年   1043篇
  1980年   923篇
  1979年   528篇
  1978年   573篇
  1977年   493篇
  1976年   476篇
  1975年   348篇
  1974年   359篇
排序方式: 共有10000条查询结果,搜索用时 19 毫秒
51.
52.
53.
54.
Usher syndrome: clinical findings and gene localization studies   总被引:3,自引:0,他引:3  
The issue of genetic heterogeneity is a critical problem in the localization of the gene(s) for Usher syndrome. Based on the data obtained on families studied to date, the differences between type I and type II Usher syndrome appear quite distinct with regard to auditory and vestibular function. Although the majority of families can be confidently diagnosed as typical type I or type II, clinical investigations revealed four families with findings that did not fit into either of the two more common subtypes. These findings emphasize the critical importance of an in-depth clinical analysis concomitant with the linkage investigation to assure accurate subtyping of Usher syndrome. Based on an analysis of only those families with definite type I or type II Usher syndrome, approximately 17% of the genome can be excluded as a potential site of the gene for type I, and 14% can be excluded as the site for the type II gene. This study will continue until the Usher gene(s) is successfully localized.  相似文献   
55.
PURPOSE: Temporomandibular joint (TMJ) arthroscopy has been considered a safe surgical procedure in the treatment of TMJ derangement. However, it is not exempt from complications. This study evaluates the complications of arthroscopy in patients with internal derangement of TMJ. PATIENTS AND METHODS: Five hundred consecutive patients (670 joints) with TMJ derangement who underwent arthroscopy between 1995 and 2004 were retrospectively analyzed. All the patients were classified as II to V in the Wilkes classification. Lysis and lavage, electrocautery of the posterior ligament, injection of corticoids, injection of ethanolamine, myotomy of lateral pterygoid muscle attachments, myotomy and electrocautery, motor debridement, injection of sodium hyaluronate, and meniscal suture were performed in different patients. RESULTS: Complications were recognized during or immediately after the surgery. They were observed in 5 of 341 (1.26%) arthroscopies of the right TMJ and 4 of 329 (1.21%) arthroscopies of the left TMJ. A 1.34% complication rate was found in the whole series. No blood clots within the external auditory canal were observed. Bleeding within the superior TMJ space was observed in 57 cases (8.5%), 36 of them in the right TMJ and 21 in the left TMJ, but they were not considered as true complications. Lacerations of the external auditory canal were found in 2 cases (0.3%), with no cases of perforation of the tympanic membrane. Lesion of the auriculotemporal nerve was observed in a case. Paresia of the facial nerve was found in 4 cases (0.6%). Alteration of visual accuracy of the ipsilateral eye was also observed in a patient immediately after the surgery. CONCLUSION: Special care must be taken to reduce complications within the upper joint space by means of an adequate instrumentation and by paying attention to essential points of the arthroscopic technique.  相似文献   
56.
Atopic eczema/dermatitis syndrome (AEDS) commonly often arises during early infancy. In several intervention studies a beneficial influence on AEDS course of certain intestinal bacteria, administered as 'probiotics', has been described. To evaluate the possible role of the natural intestinal microflora in children with allergic eczema/dermatitis syndrome regarding immediate type hypersensitivity to food allergens, children with food allergy (AAEDS, n = 68) have been compared with children without detectable food allergy (NAEDS, n = 25). All children (n = 93) in preschool age, mean age of 2.6 (+/-1.8) years, diagnosed with AEDS who were treated as inpatients in 2003 in a dermatological hospital were included. The correlation between fecal microflora, parasites and specific immunoglobulin E (IgE) antibodies against common food allergens was analyzed. A similar composition of intestinal microflora in children with AAEDS and NAAEDS was found. The food allergens that were most frequently detected were egg white, cow milk, casein, peanut and hazelnut. Furthermore, a significant association between IgE sensitization against important food allergens and components of the fecal microflora could not be demonstrated. With aging changes occur in the intestinal microbiota [Proteus/Klebsiella and age (rho = -0.607) and Enterococcus and age (rho = -0.428)]. In two subjects of the AAEDS group Blastocystis hominis was found. The composition of natural intestinal microflora in children with AAEDS and NAAEDS was similar. Hence, there is no evidence of a role of the intestinal microflora with regard to the development of infant (food) allergy in children with AEDS. The possible consequences for allergic diseases later in life require further investigation.  相似文献   
57.
58.
59.
60.
Quantitative autoradiographic analysis was used to identify regions in the brain of the male primate where androgen binding sites may be involved in the actions of testosterone. Three days after castration, adult male rhesus monkeys received a subcutaneous injection of either dihydrotestosterone propionate (DHTP, 20 mg, n = 6), testosterone propionate (TP, 100 mg, n = 2), or oil vehicle (control males, n = 4). Three hours later, 5 mCi [3H]testosterone was administered as an i.v. bolus. At 60 min, brains were rapidly removed and the left halves were used for autoradiography. In control males, highest percentages of labeled neurons (20-84% using a rigorous Poisson criterion) were observed in the ventromedial, arcuate and premammillary nuclei (n.) of the hypothalamus, medial preoptic n., bed n. of stria terminalis, intercalated mammillary n., lateral septal n. and the medial, cortical and accessory basal n. of the amygdala. Pretreatment with DHTP eliminated labeling in androgen target tissues of the genital tract, and reduced the percentages of labeled neurons to 4-22% of control values in the arcuate, lateral septal, premammillary and intercalated mammillary n., indicating that in these regions testosterone acted predominantly at androgen binding sites. However, in the medial preoptic n., the ventromedial hypothalamic n. and the accessory basal amygdaloid n., DHTP pretreatment resulted in much less blocking which, together with other data, suggested that in these sites, testosterone's actions involved aromatization and interaction with estrogen-binding sites.  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