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   125530篇
  免费   9101篇
  国内免费   211篇
耳鼻咽喉   1134篇
儿科学   3448篇
妇产科学   2591篇
基础医学   19621篇
口腔科学   3285篇
临床医学   10587篇
内科学   25461篇
皮肤病学   2165篇
神经病学   12138篇
特种医学   5119篇
外国民族医学   9篇
外科学   15751篇
综合类   523篇
现状与发展   1篇
一般理论   106篇
预防医学   14406篇
眼科学   1963篇
药学   7360篇
中国医学   235篇
肿瘤学   8939篇
  2023年   548篇
  2022年   899篇
  2021年   1955篇
  2020年   1419篇
  2019年   2062篇
  2018年   2585篇
  2017年   2199篇
  2016年   2389篇
  2015年   2671篇
  2014年   3665篇
  2013年   4783篇
  2012年   7380篇
  2011年   7444篇
  2010年   3846篇
  2009年   4037篇
  2008年   6579篇
  2007年   6803篇
  2006年   6533篇
  2005年   6196篇
  2004年   5286篇
  2003年   4991篇
  2002年   4535篇
  2001年   4434篇
  2000年   4382篇
  1999年   3903篇
  1998年   1592篇
  1997年   1308篇
  1996年   1383篇
  1995年   1124篇
  1994年   1057篇
  1993年   959篇
  1992年   2674篇
  1991年   2396篇
  1990年   2274篇
  1989年   2125篇
  1988年   1945篇
  1987年   1700篇
  1986年   1617篇
  1985年   1549篇
  1984年   1107篇
  1983年   963篇
  1982年   518篇
  1981年   453篇
  1980年   389篇
  1979年   857篇
  1978年   520篇
  1977年   424篇
  1974年   417篇
  1973年   409篇
  1972年   366篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
81.
Measurements of toe temperature and transcutaneous PO2 (PtcO2) have been both suggested for non-invasive assessment of peripheral blood flow in acute circulatory failure. The underlying principle of the two methods is that cutaneous vasoconstriction occurs early when tissue perfusion is altered. In 15 patients, we compared the two measurements during cardiogenic shock (27 measurements) or septic shock (29 measurements). Toe-ambiant temperature gradient and PtcO2 correlated well together (r=0.66, p(0.001) especially in hyperkinetic septic shock (r=0.79, p(0.001). In cardiogenic shock, toe-ambiant temperature correlated well with cardiac index (r=0.63), stroke index (r=0.64) and oxygen transport (r=0.65), and these correlations were stronger than for PtcO2. In septic shock, both techniques were poor indicators of blood flow indexes but PtcO2 rather correlated with arterial pressure (r=0.66) and left ventricular work (r=0.66). Trend evaluation of data revealed in cardiogenic shock that the increase in toe temperature usually preceded the increase in PtcO2. Since measurement of PtcO2 is technically more complicated, correlates less well with standard hemodynamic parameters and later reflects cardiovascular improvement, it has no advantage over measurement of toe temperature in circulatory shock. In cardiogenic shock, measurements of toe temperature can reliably track cardiac output changes. In septic states, however, non-invasive assessment of skin perfusion is of limited interest.  相似文献   
82.
Serum prostatic-specific antigen (PSA) and prostatic acid phosphatase (PAP) were determined simultaneously in 241 patients presented to the Urology Department. The patients consisted of 140 prostatic carcinoma patients (34 newly diagnosed and 106 previously treated) and 101 patients with benign prostatic hypertrophy (BPH). Prostatic acid phosphatase was measured by two different methods, an enzymatic method (PAP-EA, Boehringer) with tartrate inhibition and an immunoenzymetric assay (PAP-IEMA, Hybritech). The concentration of prostatic specific antigen in serum was measured using a recently introduced immunoradiometric assay (PSA-IRMA, Hybritech). Receiver operating characteristic curves were constructed to compare the diagnostic value of the different tests at different cutoff values. The diagnostic efficiencies of the PAP-EA and the PAP-IEMA appeared to be similar. A better diagnostic efficiency for PSA compared to PAP was found independent of the cutoff value. The upper-normal limit of 2.7 micrograms/l for PSA, as suggested by the manufacturer and mentioned in the literature introduces too many false-positive results. We therefore selected 10 micrograms/l as the upper-normal limit for PSA (sensitivity 57%, specificity 88%). Combined sensitivity found for PAP + PSA was 37% with a specificity of 97%. A literature survey is included to allow better comparison with data published elsewhere.  相似文献   
83.
Dexenfluramine, an effective and safe serotoninergic drug with anorectic and possible food-selection-tuning properties, was investigated in a placebo-controlled study of 1 year's duration in severe and refractory obesity. The aim of the study was to assess weight loss, and changes in cardiovascular risk factors, food intake and eating behaviour. Dexfenfluramine- and placebo-treated patients achieved a similar weight loss (greater than 10% of initial weight, by 39.5 and 30.0%, greater than 20% of initial overweight by 42.1% and 32.5% and greater than 10 kg by 41.4 and 33.3%, respectively, of the initial cohorts). Furthermore, the decreases in weight (10.7 vs. 8.0 kg), in body mass index (3.9 vs. 2.9 kg m2) and in waist/hip ratio (0.04 vs. 0.02) were not significantly different. After discontinuation of the drug, the increase in weight (2.8 vs. 1.0 kg) was significantly higher in the dexfenfluramine-treated group. Except for a borderline better effect on glucose of dexfenfluramine, both groups showed similar beneficial changes in food intake and cardiovascular risk factors. Eating behaviour in response to emotional and external stimuli was comparable in the two groups, but placebo-treated patients had to restrain their eating more in order to achieve the same weight loss. Notwithstanding the fact that weight losses and an associated amelioration of health-risk factors were of similar magnitude in dexfenfluramine- and placebo-treated patients, dexfenfluramine might have a useful role in promoting a less stressed adherence to prolonged restriction of energy intake in the severe and refractory obese subject.  相似文献   
84.
85.
86.
87.
88.
Optimal treatment of Smith's fracture remains controversial. Conservative management of type III fractures is acceptable, but results are moderate for types I and II.

This study includes 53 patients operated on during the past 10 years; six of type I, 17 of type II and 30 of type III.

The functional end result was good in 32 cases (60.3 per cent) and excellent in nine cases (16.9 per cent).

Functional results of types I, II and III were comparable when the excellent and good groups were added together.

There was no correlation between anatomical result and functional outcome (κ = 0.07), although a good anatomical result usually accompanied a good to excellent functional end result. Operative treatment of Smith's fractures have good functional end results in our hands, regardless of the fracture type.  相似文献   

89.
90.
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