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   835篇
  免费   41篇
耳鼻咽喉   6篇
儿科学   24篇
妇产科学   40篇
基础医学   106篇
口腔科学   5篇
临床医学   71篇
内科学   107篇
皮肤病学   3篇
神经病学   124篇
特种医学   73篇
外科学   67篇
综合类   1篇
预防医学   55篇
眼科学   3篇
药学   109篇
肿瘤学   82篇
  2021年   8篇
  2020年   9篇
  2019年   12篇
  2018年   11篇
  2017年   11篇
  2016年   12篇
  2015年   13篇
  2014年   10篇
  2013年   28篇
  2012年   23篇
  2011年   27篇
  2010年   16篇
  2009年   23篇
  2008年   32篇
  2007年   35篇
  2006年   26篇
  2005年   35篇
  2004年   38篇
  2003年   37篇
  2002年   30篇
  2001年   28篇
  2000年   30篇
  1999年   17篇
  1998年   12篇
  1997年   10篇
  1996年   11篇
  1995年   7篇
  1992年   24篇
  1991年   11篇
  1990年   17篇
  1989年   10篇
  1988年   17篇
  1987年   11篇
  1986年   14篇
  1985年   12篇
  1984年   13篇
  1983年   9篇
  1982年   8篇
  1981年   9篇
  1980年   7篇
  1979年   13篇
  1978年   18篇
  1977年   9篇
  1976年   7篇
  1975年   15篇
  1974年   7篇
  1969年   6篇
  1968年   7篇
  1967年   14篇
  1965年   7篇
排序方式: 共有876条查询结果,搜索用时 15 毫秒
1.
2.
With spinal anesthesia the level of surgical analgesia is mostly reported without reference to the neuroanatomic map of spinal nerves. The classical maps are variably and inconsistently reported in many textbooks. Because of the differences between the classical maps of Keegan and Garrett and of Foerster, and also because of the variability in their interpretation, we applied them to the same clinical data. This resulted in a theoretically clinically significant difference of two segments. It is concluded that clear reference should be made to the implemented segmental map in expressing the level of spinal blockade.  相似文献   
3.
The aim was to investigate to what extent low Apgar scores are linked to the partogram's result and, more specifically, if the action line should be set 3 rather than 4 h parallel and right to the alert line. Some 24.0% of all labours evolved left to the alert line and 26.3% of the labours right to the alert line crossed the 4-h action line. An Apgar score of 相似文献   
4.
5.
6.
7.
8.
To determine the physiology of acid secretion after gastrocystoplasty with the body of the stomach we performed a prospective standardized 3-day study in 13 children (median age 12.5 years) who had undergone bladder augmentation/replacement (median postoperative period 2 years). Urinary pH and titratable acid, and serum gastrin levels were measured after gastric distention with a meal and bladder distention with urethral filling at baseline and after medication with a histamine-2 receptor antagonist or an anticholinergic agent. Five children underwent cystoscopy and biopsy of the gastric and native segments of the gastrocystoplasty.

In the fasting state pH was neutral, there was no titratable acid in the urine and serum gastrin level was normal in all cases. After a meal urinary acid secretion and serum gastrin level increased markedly. After each medication half of the patients demonstrated marked inhibition of urinary acid secretion after a meal while response was partial in the remainder. In none of the patients was there significant alteration in the pattern of gastrin secretion. Bladder distention did not result in urinary acid secretion or gastrin secretion. The cystoscopic and histological appearance of the native bladder and stomach segment of the gastrocystoplasty in the 5 patients was normal. We conclude that the gastric body segment used in gastrocystoplasty continues to secrete acid as though it were part of the stomach. The secretion of acid in the urine can be decreased with histamine-2 receptor antagonist or anticholinergic medication.  相似文献   

9.
Genital asymmetry in men   总被引:1,自引:0,他引:1  
This study examined genital asymmetry in a large sample of men. The probands were 6544 non-delinquent men who were interviewed by the Kinsey Institute for Research in Sex, Gender and Reproduction from 1938 to 1963. The measures were four indicators of penile and scrotal asymmetry, along with self-reported handedness, from Kinsey's interview protocol. Most men reported some degree of lateral asymmetry in their flaccid penis and in their testicles; less asymmetry was reported for their erect penis. The asymmetry typically occurred in the left direction, and this pattern occurred in both right- and nonright- handers. However, this 'leftward' pattern was significantly less pronounced in nonright-handers. The results are discussed in relation to previous findings of genital asymmetry in men, the possible relationship of genital asymmetry to functional cerebral asymmetry, and recent data suggesting genital asymmetry may predict patterns of cognitive performance and genital/sexual organ cancers.   相似文献   
10.
The molecular epidemiological characteristics of all Streptococcus pneumoniae strains isolated in a nationwide manner from patients with meningitis in The Netherlands in 1994 were investigated. Restriction fragment end labeling analysis demonstrated 52% genetic clustering among these penicillin-susceptible strains, a value substantially lower than the percentage of clustering among Dutch penicillin-nonsusceptible strains. Different serotypes were found within 8 of the 28 genetic clusters, suggesting that horizontal transfer of capsular genes is common among penicillin-susceptible strains. The degree of genetic clustering was much higher among serotype 3, 7F, 9V, and 14 isolates than among isolates of other serotypes, i.e., 6A, 6B, 18C, 19F, and 23F. We further studied the molecular epidemiological characteristics of pneumococci of serotype 3, which is considered the most virulent serotype and which is commonly associated with invasive disease in adults. Fifty epidemiologically unrelated penicillin-susceptible serotype 3 invasive isolates originating from the United States (n = 27), Thailand (n = 9), The Netherlands (n = 8), and Denmark (n = 6) were analyzed. The vast majority of the serotype 3 isolates (74%) belonged to two genetically distinct clades that were observed in the United States, Denmark, and The Netherlands. These data indicate that two serotype 3 clones have been independently disseminated in an international manner. Seven serotype 3 isolates were less than 85% genetically related to the other serotype 3 isolates. Our observations suggest that the latter isolates originated from horizontal transfer of the capsular type 3 gene locus to other pneumococcal genotypes. In conclusion, epidemiologically unrelated serotype 3 isolates were genetically more related than those of other serotypes. This observation suggests that serotype 3 has evolved only recently or has remained unchanged over long periods.  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