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   7377篇
  免费   491篇
  国内免费   16篇
耳鼻咽喉   113篇
儿科学   229篇
妇产科学   132篇
基础医学   1153篇
口腔科学   130篇
临床医学   690篇
内科学   1707篇
皮肤病学   351篇
神经病学   541篇
特种医学   223篇
外科学   973篇
综合类   102篇
一般理论   7篇
预防医学   552篇
眼科学   86篇
药学   484篇
中国医学   2篇
肿瘤学   409篇
  2023年   56篇
  2022年   85篇
  2021年   136篇
  2020年   116篇
  2019年   173篇
  2018年   173篇
  2017年   144篇
  2016年   175篇
  2015年   139篇
  2014年   230篇
  2013年   335篇
  2012年   394篇
  2011年   430篇
  2010年   218篇
  2009年   236篇
  2008年   427篇
  2007年   389篇
  2006年   412篇
  2005年   364篇
  2004年   325篇
  2003年   327篇
  2002年   322篇
  2001年   131篇
  2000年   126篇
  1999年   125篇
  1998年   88篇
  1997年   66篇
  1996年   63篇
  1995年   64篇
  1994年   47篇
  1993年   38篇
  1992年   80篇
  1991年   99篇
  1990年   77篇
  1989年   73篇
  1988年   58篇
  1987年   80篇
  1986年   87篇
  1985年   70篇
  1984年   74篇
  1983年   62篇
  1982年   58篇
  1981年   39篇
  1980年   31篇
  1979年   44篇
  1978年   32篇
  1974年   31篇
  1972年   35篇
  1971年   39篇
  1967年   33篇
排序方式: 共有7884条查询结果,搜索用时 31 毫秒
1.
2.
Treatment of non-seminomatous testicular cancer often leadsto infertility due to anejaculation/retrograde ejaculation andpoor sperm quality. In these men spermatozoa may be obtainedby transrectal electroejaculation (TE), but the optimal strategyfor assisted procreation in these couples is not known. Ouraim was to examine whether TE and conventional in-vitro fertilization(IVF) would be successful. A total of 10 couples, with long-standinginfertility due to anejaculation or retrograde ejaculation aftertreatment for testicular cancer 5–14 years earlier, werereferred to our unit. All men underwent diagnostic TE undergeneral anaesthesia. Spermatozoa were recovered in nine cases.The antegrade fraction was prepared and used for IVF. Spermquality was variable and conventional IVF was considered impossiblein three cases. Altogether six IVF treatment cycles in six couplesresulted in five pregnancies, of which four resulted in a deliveryand one resulted in a spontaneous abortion. One additional pregnancyis ongoing after transfer of cryopreserved embryos. The fertilizationrate was 54% (33/61) and the cleavage rate was 97% (32/33).No complications relating to the procedure have been encountered.  相似文献   
3.
Posttraumatic enophthalmos is a cosmetic orbital deformity that may induce a secondary visual dysfunction. Two case reports are presented which review the pathophysiology, incidence, clinical and radiological examination, and treatment of posttraumatic enophthalmos.  相似文献   
4.
5.
6.
Sex-specific effects for body mass index (BMI) were explored in a newly established, population-based Norwegian twin panel. The sample includes 5,864 individuals, aged 18–25 years, who responded to a questionnaire containing items for zygosity classification, height, weight, health, health-related behaviors, well-being, and demographic information. Among the 2,570 intact pairs who returned the questionnaire there were 416 identical (MZ) male pairs, 387 fraternal (DZ) male pairs, 528 MZ female pairs, 443 DZ female pairs, and 796 unlike-sexed pairs. Alternate sets of models testing for either sex-specific genetic or environmental parameters were evaluated using structural equation analysis. Results from the most parsimonious model indicated that the genes contributing to variation in BMI are not identical for men and women; rather, some genetic effects were shared by the sexes and some were unique to each sex. Total variation in BMI could be explained by sex-specific additive genetic effects, as well as genetic and non-shared environmental effects common to men and women. Estimates of heritability were .708 for men and .789 for women, and the male-female genetic correlation was 0.622. The series of models specifying sex-specific shared environment also fit the data and suggests that shared environmental factors may be important for males but not for females. The findings raise questions concerning the relationship between sex-specific effects for BMI and sex differences in health outcomes. ©1995 Wiley-Liss, Inc.  相似文献   
7.
Appendicitis is the commonest acute surgical emergency of childhood, and occurs in approximately 2–4 per 1000 infants. It is usually seen in infants older than 5 years but can occur at any age. Atypical clinical findings are seen in 30–50% of children, especially the younger ones, and often leads to a delayed diagnosis. Preoperative clinical assessment alone has yielded an accuracy ranging between 70 and 90% but is associated with a normal appendectomy rate of 13–25%. Preoperative imaging using the graded compression US technique and/or different helical CT techniques has been able to reduce this rate to 3–7% without an increase in perforation rate. An extensive review of the literature revealed several papers examining the accuracy of different imaging modalities and strategies of acute appendicitis in children. The reported sensitivity of US varied between 87 and 95%, vs 95–97% for helical CT, while the specificity ranged between 85 and 98% for US and 94 and 97% for helical CT. Only one truly randomised study was found, showing that compared with US alone, a combination of US and helical CT increased the sensitivity from 86 to 99%, while the specificity decreased from 95 to 89%. We conclude that imaging should be performed in all children with suspected appendicitis and that US should be the initial procedure with CT as a complementary tool.  相似文献   
8.
In order to assess the diagnostic outcome of a screening for primary hyperparathyroidism (PHPT) in an elderly population, we determined ionized calcium in serum from 368 individuals participating in a health control at M?lnlycke Primary Care Centre (200 women, 168 men; age range 75-95 years); four-fifths of the individuals living in their homes, the remainder in homes for aged or nursing homes. Intact parathyroid hormone was determined in the samples with oinized calcium concentration greater than mean + 3SD of the truncated population sample, and these individuals were also recalled for another blood sample. Moderate hypercalcaemia, probably due to PHPT, was found in eight individuals (2% of the complete sample, 3% of the women), five having neuropsychiatric or neuromuscular symptoms consistent with PHPT. Surgical intervention is probably indicated in only a small proportion of elderly patients. We conclude that optimal benefits in relation to costs of screening for PHPT in old people will depend on the availability of a safe and simple pharmacological treatment that could determine any causal relationship between hypercalcaemia and symptoms.  相似文献   
9.
10.
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