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   1495838篇
  免费   112257篇
  国内免费   3021篇
耳鼻咽喉   21271篇
儿科学   46021篇
妇产科学   40625篇
基础医学   223887篇
口腔科学   43664篇
临床医学   133033篇
内科学   282733篇
皮肤病学   31632篇
神经病学   113813篇
特种医学   58149篇
外国民族医学   242篇
外科学   229158篇
综合类   37679篇
现状与发展   3篇
一般理论   408篇
预防医学   113376篇
眼科学   35534篇
药学   113545篇
  3篇
中国医学   3786篇
肿瘤学   82554篇
  2018年   14413篇
  2016年   12655篇
  2015年   14450篇
  2014年   20246篇
  2013年   30596篇
  2012年   40942篇
  2011年   43056篇
  2010年   25348篇
  2009年   23829篇
  2008年   40497篇
  2007年   44034篇
  2006年   44161篇
  2005年   42505篇
  2004年   41677篇
  2003年   39913篇
  2002年   38590篇
  2001年   67633篇
  2000年   69002篇
  1999年   57722篇
  1998年   16316篇
  1997年   14479篇
  1996年   14614篇
  1995年   13850篇
  1994年   13094篇
  1992年   47128篇
  1991年   46482篇
  1990年   45567篇
  1989年   44501篇
  1988年   41158篇
  1987年   40159篇
  1986年   38235篇
  1985年   36649篇
  1984年   27763篇
  1983年   23676篇
  1982年   14136篇
  1981年   12853篇
  1980年   12191篇
  1979年   27039篇
  1978年   19390篇
  1977年   16392篇
  1976年   15352篇
  1975年   16750篇
  1974年   20352篇
  1973年   19462篇
  1972年   18444篇
  1971年   17157篇
  1970年   16429篇
  1969年   15649篇
  1968年   14221篇
  1967年   12994篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
91.
The role of caffeine or coffee in causing or promoting the incidence of serious disease is equivocal. Two design factors may account for the discrepancies in reported findings on the effects of coffee drinking: (a) imprecision of measurement and (b) confounding variables. A study of 2,714 white U.S. adults disclosed that, of 32 risk factors analyzed by linear and logistic regression, only sex and cigarette smoking were found to be important potential confounders of caffeine and coffee intake. Partial R2 values of the other 30 risk factors were relatively small and were inconsistent for each sex. It is unlikely that any of these factors could explain any of the reported associations between caffeine or coffee consumption and certain diseases. However, certain weak associations with caffeine or coffee intake should be included in the study design when they are known to be risk factors of a disease under investigation. These factors for men are dietary fat intake, vitamin C intake, and body mass index; and for women are vitamin use, alcohol intake, stress, and perceived health status.  相似文献   
92.
93.
Abstract Perioscan requires a plaque sample to detect the presence of enzymes capable of degrading N-benzoyl-DL-arginine-2-naphthylamide (BANA) from relatively few anaerobic periodontal pathogens. Periocheck assays the presence of neutral proteases in crevicular fluid. The aim of this study was to compare these test kits with traditional clinical methods of detecting periodontal disease and to monitor the ability of the kits to reflect the response to initial therapy. 19 patients with moderately severe chronic periodontitis were seen before and after a course of oral hygiene and root instrumentation consisting of 4 appointments. Clinical measurements and test assays were collected at 5 diseased sites and 2 healthy sites in each subject. Complete data from 125 sites were available for statistical analysis. At baseline Periocheck had a sensitivity of 88% and a specificity of 61% whereas Perioscan had a sensitivity of 99% and a specificity of 55%, when related to the clinical diagnosis. A composite clinical assessment, based on improvement or deterioration of one whole unit change of the subjective clinical indices and 2mm changes or greater in probing depth or probing attachment level, revealed 75 sites which improved following treatment, whereas 45 sites did not change and 5 sites deteriorated. The probability that the tests agreed with the clinical outcome after treatment, was calculated as 50.4% for Periocheck and 52% for Perioscan. The diagnostic kits did not reliably reflect the clinical assessment of periodontal disease in the cross sectional study, or the outcome following treatment.  相似文献   
94.
95.
96.
Bladder mucosa in urethral reconstructions   总被引:6,自引:0,他引:6  
  相似文献   
97.
A retrospective analysis of results of treatment of 104 patients with fractures of long tubular bones associated with injuries of peripheral nerves has shown complex therapy to be necessary. Main components of this treatment were biogenic stimulators, vitamin B12, spasmolytic and dehydration drugs in combination with electrophoresis with potassium iodide and thermal procedures. Rapid disturbance of conductivity of nerve trunks after trauma should be followed by revision of the given segment of the extremity in order to remove hematoma and make reposition of displaced fragments of the bone, which can provide recovery of the disturbed function of the nerve.  相似文献   
98.
Thirteen cases of primary appendicular adenocarcinoma are reported. This rare tumour usually presents as acute appendicitis. The correct diagnosis is rarely entertained before or during surgery. The main treatment choice lies between appendicectomy alone and appendicectomy followed by right hemicolectomy. There are anatomical reasons for advising the latter and survival figures from the literature tend to support this preference. The cases reported here indicate that in the period 1972-1984, in the North West Region, there was a slight preference for appendicectomy alone. The additional procedure of right hemicolectomy did not confer any clear-cut survival advantage.  相似文献   
99.
100.
Patient history and clinical examination are important for the diagnosis of degenerative joint disease. Here the typical statements of a patient suffering from early osteoarthritis are described and, as far as possible, explained. The joint in question must be systematically examined. Furthermore, the neighboring joints and soft-tissue structures, i.e., muscles, tendons etc., should be examined and evaluated with respect to their importance in hindering the functional chain. The neuroreflectory mechanisms involved herein are described.  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