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   12597篇
  免费   530篇
  国内免费   102篇
耳鼻咽喉   91篇
儿科学   260篇
妇产科学   172篇
基础医学   1411篇
口腔科学   222篇
临床医学   723篇
内科学   3675篇
皮肤病学   351篇
神经病学   825篇
特种医学   409篇
外科学   1991篇
综合类   59篇
预防医学   360篇
眼科学   152篇
药学   635篇
中国医学   49篇
肿瘤学   1844篇
  2024年   15篇
  2023年   87篇
  2022年   133篇
  2021年   254篇
  2020年   141篇
  2019年   187篇
  2018年   284篇
  2017年   199篇
  2016年   253篇
  2015年   273篇
  2014年   374篇
  2013年   413篇
  2012年   744篇
  2011年   819篇
  2010年   467篇
  2009年   371篇
  2008年   792篇
  2007年   853篇
  2006年   782篇
  2005年   850篇
  2004年   860篇
  2003年   879篇
  2002年   834篇
  2001年   151篇
  2000年   106篇
  1999年   172篇
  1998年   199篇
  1997年   144篇
  1996年   164篇
  1995年   160篇
  1994年   143篇
  1993年   106篇
  1992年   100篇
  1991年   105篇
  1990年   71篇
  1989年   79篇
  1988年   76篇
  1987年   53篇
  1986年   38篇
  1985年   54篇
  1984年   64篇
  1983年   43篇
  1982年   51篇
  1981年   53篇
  1980年   21篇
  1979年   34篇
  1978年   19篇
  1977年   16篇
  1975年   18篇
  1974年   12篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
31.
32.
Single photon emission computerized tomography (SPECT) is now widely used as one of the tools in evaluating cerebral blood flow (CBF). The authors report the CBF changes in childhood hydrocephalus. Five pediatric cases studied by 123I-IM SPECT in children are presented. The authors counted radioactivities both in early and delayed images in each patient, and calculated the reabsorption ratio (RR). Two negative-RR cases and three positive-RR cases were found. All of the negative-RR patients had a poor prognosis, while all of the positive-RR patients had a favorable outcome.  相似文献   
33.
A 69-year-old man was admitted to hospital because of sustainedventricular tachycardia with right bundle branch block morphology.After abolition of ventricular tachycardia, an electrocardiogramshowed atrial fibrillation, complete right bundle  相似文献   
34.
The diuretic and the antihypertensive actions of torasemide were examined in renal and genetic hypertensive rats and compared to the effects of furosemide. Oral administration of torasemide (1 and 3 mg/kg) elicited a dose-dependent increase in the excretion of urine and electrolytes and elevated the urinary Na/K ratio in both renal and genetic hypertensive rats. Torasemide and furosemide had a similar maximum diuretic effect in the normotensive Wistar rat and the spontaneously hypertensive rat (SHR). However, the diuretic activity of furosemide was weaker in the renal hypertensive rat (RHR). Torasemide showed approximately 30 times greater diuretic potency than furosemide. Torasemide and furosemide demonstrated hypotensive action in hypertensive rat models, but not in the normotensive Wistar rat. Especially in the RHR, torasemide exhibited a more potent hypotensive action than furosemide. These results show that the diuretic and antihypertensive activities of torasemide are effective in various rat models of hypertension, while the diuretic activity of furosemide is weak in certain hypertensive rat models. © 1992 Wiley-Liss, Inc.  相似文献   
35.
Trichorhinophalangeal syndrome (TRPS) type I is characterized by slowly progressing systemic osseous dysplasia, exhibiting craniofacial and other skeletal deformities. However, there have been few reports describing this syndrome after undergoing orthognathic surgery. In this report, we present a patient with TRPS I who successfully underwent orthognathic surgery. In addition, we examined the skeletal stability of the patient for 2 years after the surgery.  相似文献   
36.
We performed laparoscopic appendectomy and drainage to treat panperitonitis due to perforated appendicitis that occurred in a 28‐year‐old woman. We believe this is an appropriate procedure to treat perforated appendicitis because it is safe and minimally invasive, and faster recovery can be expected than after conventional open appendectomy.  相似文献   
37.
Clinical diagnosis of chronic cholecystitis is made based on diffuse hyperechoic thickening of the gallbladder wall as shown by ultrasonographic examination. We herein report three cases of chronic cholecystitis showing localized hypoechoic thickening of the gallbladder wall that mimicked gallbladder cancer by ultrasonography. Histologically, hypertrophy of the muscularis propria was a common characteristic finding in these three patients. A smooth surface of the inner hypoechoic layer of the thickened wall was considered to be a reliable finding in the differential diagnosis between this type of chronic cholecystitis and gallbladder cancer.  相似文献   
38.
Background: The aim of this study was to investigate the effects of two imidazoline-derived intravenous anesthetics, etomidate and midazolam, on vascular adenosine triphosphate-sensitive potassium (KATP) channel activity.

Methods: In isolated rat aorta, isometric tension was recorded to examine the anesthetic effects on vasodilator response to levcromakalim, a selective KATP channel opener. Using the patch clamp method, the anesthetic effects were also examined on the currents through (1) native vascular KATP channels, (2) recombinant KATP channels with different combinations of various types of inwardly rectifying potassium channel (Kir6.0 family: Kir6.1, 6.2) and sulfonylurea receptor (SUR1, 2A, 2B) subunits, (3) SUR-deficient channels derived from a truncated isoform of Kir6.2 subunit (Kir6.2[DELTA]C36 channels), and (4) mutant Kir6.2[DELTA]C36 channels with reduced sensitivity to adenosine triphosphate (Kir6.2[DELTA]C36-K185Q channels).

Results: Etomidate (>= 10-6 m), but not midazolam (up to 10-6 m), inhibited the levcromakalim-induced vasodilation, which was sensitive to glibenclamide (IC50: 7.21 x 10-8 m; maximum inhibitory concentration: 1.22 x 10-4 m). Etomidate (>= 3 x 10-6 m), but not midazolam (up to 10-4 m), inhibited the native KATP channel activity in both cell-attached and inside-out configurations with IC50 values of 1.68 x 10-5 m and 1.52 x 10-5 m, respectively. Etomidate (10-5 m) also inhibited the activity of various types of recombinant SUR/Kir6.0KATP channels, Kir6.2[DELTA]C36 channels, and Kir6.2[DELTA]C36-K185Q channels with equivalent potency.  相似文献   

39.
40.
BACKGROUND: To establish the criteria for selecting a mitral annuloplasty ring of the correct size, the dimensions of the mitral valve orifice were analyzed in cadaveric hearts. MATERIALS AND RESULTS: From December 2000 to July 2006, the mitral valve diameter [DM (Obs)] and Z-values [DM (Z); standardized value based on Rowlatt's criteria], the angles of the trigones (theta Tg) and commissures (theta Com) and the intertrigonal distance [L (T)] were measured in 82 fresh cadaveric hearts from cases with variable causes of death (mean age 64.8+/-15.7 years; body surface area [BSA] 1.51+/-0.21 m2). DM (Obs), DM (Z) and L (T) were 2.8+/-0.5 cm, 1.16+/-0.98, and 1.8+/-0.2 cm, respectively. Theta Tg and theta Com averaged 76+/-13 and 121+/-11 degrees, respectively. There was a significant inverse linear relationship between DM (Z) and theta Tg [theta Tg =-10x DM (Z) +88] and a significant logarithmic correlation between L (T) and BSA [L (T) =0.54xLn (BSA) +1.55]. The anterior annular length and L (T) remained unchanged. CONCLUSION: In non-dilated cadaveric hearts, the trigones were located at one-quarter of the mitral annulus, so the appropriate length of the posterior annuloplasty band should be adjusted to L (T) x3.33.  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