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   13377篇
  免费   565篇
  国内免费   112篇
耳鼻咽喉   98篇
儿科学   271篇
妇产科学   190篇
基础医学   1496篇
口腔科学   250篇
临床医学   758篇
内科学   3800篇
皮肤病学   362篇
神经病学   906篇
特种医学   390篇
外科学   2171篇
综合类   59篇
预防医学   382篇
眼科学   231篇
药学   755篇
中国医学   51篇
肿瘤学   1884篇
  2023年   90篇
  2022年   138篇
  2021年   258篇
  2020年   149篇
  2019年   191篇
  2018年   302篇
  2017年   203篇
  2016年   263篇
  2015年   283篇
  2014年   392篇
  2013年   432篇
  2012年   768篇
  2011年   860篇
  2010年   478篇
  2009年   391篇
  2008年   831篇
  2007年   898篇
  2006年   824篇
  2005年   894篇
  2004年   887篇
  2003年   913篇
  2002年   868篇
  2001年   174篇
  2000年   129篇
  1999年   196篇
  1998年   207篇
  1997年   151篇
  1996年   166篇
  1995年   156篇
  1994年   141篇
  1993年   99篇
  1992年   139篇
  1991年   135篇
  1990年   92篇
  1989年   90篇
  1988年   86篇
  1987年   72篇
  1986年   60篇
  1985年   75篇
  1984年   76篇
  1983年   57篇
  1982年   62篇
  1981年   60篇
  1980年   27篇
  1979年   43篇
  1978年   28篇
  1977年   18篇
  1975年   25篇
  1973年   17篇
  1968年   16篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
41.
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   
42.
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   
43.
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   
44.
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   
45.
The identification and diagnosis of thyroid metastases from renal cell carcinoma are rare in living patients in spite of more frequent incidence during autopsy. We reported two cases of thyroid metastases from renal cell carcinoma. In both cases, histological examination revealed metastasis from renal cell carcinoma and negative immunohistological stain for thyroglobulin ruled out primary thyroid carcinoma.  相似文献   
46.
The changes in myocardial blood flow and systemic hemodynamics during hypotensive anesthesia with adenosine triphosphate (ATP) or ATP with dipyridamole (0.5 mg.kg-1) were studied in 20 mongrel dogs anesthetized with 0.7% halothane in 100% oxygen. In both groups, mean arterial blood pressure (MAP) was reduced to 60 mmHg by intravenous administration of ATP. During hypotensive anesthesia, coronary blood flow, myocardial blood flow and cardiac index increased significantly in both groups. Lactic acid and uric acid increased significantly during hypotensive anesthesia in the group 1. Heart rate, MAP, systemic vascular resistance and coronary vascular resistance decreased significantly during hypotensive anesthesia in both groups. Mean pulmonary arterial pressure, pulmonary arterial wedge pressure and central venous pressure showed no significant changes in both groups. Base excess in the group 1 increased markedly compared with the group 2. We conclude that pretreatment with dipyridamole can prevent metabolic acidosis that occurs during hypotensive anesthesia induced by ATP.  相似文献   
47.
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   
48.
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   

49.
50.
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