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   9593篇
  免费   546篇
  国内免费   88篇
耳鼻咽喉   106篇
儿科学   475篇
妇产科学   363篇
基础医学   1243篇
口腔科学   188篇
临床医学   800篇
内科学   2329篇
皮肤病学   204篇
神经病学   716篇
特种医学   571篇
外科学   1261篇
综合类   63篇
预防医学   620篇
眼科学   176篇
药学   574篇
  2篇
中国医学   34篇
肿瘤学   502篇
  2022年   54篇
  2021年   108篇
  2020年   82篇
  2019年   131篇
  2018年   159篇
  2017年   110篇
  2016年   111篇
  2015年   177篇
  2014年   237篇
  2013年   285篇
  2012年   369篇
  2011年   396篇
  2010年   279篇
  2009年   249篇
  2008年   455篇
  2007年   549篇
  2006年   510篇
  2005年   494篇
  2004年   453篇
  2003年   401篇
  2002年   440篇
  2001年   370篇
  2000年   392篇
  1999年   310篇
  1998年   214篇
  1997年   221篇
  1996年   203篇
  1995年   173篇
  1994年   169篇
  1993年   157篇
  1992年   199篇
  1991年   187篇
  1990年   158篇
  1989年   151篇
  1988年   148篇
  1987年   148篇
  1986年   119篇
  1985年   112篇
  1984年   74篇
  1983年   53篇
  1982年   50篇
  1981年   58篇
  1980年   39篇
  1979年   34篇
  1978年   26篇
  1977年   34篇
  1976年   40篇
  1975年   25篇
  1970年   32篇
  1968年   35篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
61.
62.
Rupture of an intra-aortic balloon counterpulsator (IABCP) demands immediate removal. We report a case of thrombus formation within a Datascope IABCP secondary to IABCP rupture, necessitating surgical exploration for removal. There is a disturbing pattern of balloon ruptures with this type of IABCP.  相似文献   
63.
64.
To evaluate the potential advantages of the administration of extradural morphine to control postoperative pain and its effects on respiratory function, 39 patients were randomly assigned to one of two groups before aortic surgery. The first group (20 patients) received intravenous analgesia as required (control group). The second group (19 patients) received extradural morphine in a programmed fashion. During the immediate postoperative period the following parameters were measured in both groups: respiratory rate, vital capacity, peak expiratory volume in the first second, PaO2, PaCO2, arterial pH, heart rate, and systolic and diastolic blood pressure. In the group treated with morphine the postoperative increase in heart and respiratory rate was significantly smaller than in the control group (p less than 0.01). Postoperative forced pulmonary volumes were higher in the morphine group (p less than 0.01). However, there were no differences in time of hospitalization between both groups. There were more complications in the control group, but the difference did not reach statistical significance.  相似文献   
65.
We evaluated the effects of the use of 1.2% isoflurane (group A) in a group of patients (n = 13) referred for mitral valve surgery, with pulmonary hypertension and right ventricular failure. We evaluated the hemodynamic status in baseline conditions, after isoflurane ++ administration and in relative hyper- and hypovolemia. We compared the results with those in 17 patients (group B) in identical clinical state who did not receive isoflurane during anesthesia. The evaluated parameters were: mixed venous Hb saturation (SvO2), heart rate (HR), pulmonary capillary pressure (PCP), central venous pressure (CVP), mean blood pressure (mBP), mean pulmonary arterial pressure (mPAP), cardiac index (CI), arteriolar pulmonary resistances (APR), peripheral vascular resistances (SVR), stroke index (SI), left ventricular work (LVW), right ventricular work (RVW), and O2 consumption (VO2). In group A, after isoflurane ++ administration, CI was 107.05% and 80% of baseline values in relative hypervolemia and hypovolemia, respectively. In group B (control), CI was 121.48% and 88.28% of basal values in relative hypervolemia and hypovolemia, respectively. In group A, SVR were 73.59% and 76.72% in hypervolemia and hypovolemia, respectively, while in group B they were 86.21% and 106.80%. In group A, APR were 90.85% and 89.96% in hypervolemia and hypovolemia, while they were 80.72% and 102.34% in group B. We found that isoflurane results in a greater peripheral than pulmonary vasodilation with a greater impairment in right ventricular function.  相似文献   
66.
67.
Dumas  JM; Edde  DJ 《Radiology》1986,160(2):453-456
In a prospective study conducted over a 12-month period, 30 patients underwent double-contrast arthrography of the knee followed by arthroscopic study. An 80% correlation rate was found between results. Arthrography had a higher rate of accuracy (93%) than arthroscopy (84%) and had a 7% false-positive and 0% false-negative rate. A commonly overlooked arthrographic sign--the triple-S or stuck sail sign--was 91% accurate in the prediction of meniscal tears. The complementary nature of the two examinations is discussed.  相似文献   
68.
69.
The renal insulin-like growth factor-I (IGF-I) system has been implicated in the pathogenesis of renal hypertrophy, altered hemodynamics, and extracellular matrix expansion associated with early diabetes. The relative abundance of IGF binding proteins (IGFBPs) in the renal microenvironment may modulate IGF-I actions. However, the precise IGFBPs expressed in the glomerular and tubulointerstitial compartments during diabetic renal growth have not been characterized. In the present study, in situ hybridization studies were performed to examine the expression of IGFBP-1 to -6 messenger RNAs (mRNAs) 3, 7, and 14 days after streptozotocin (STZ) injection in rats. In control, nondiabetic kidneys, all six IGFBP mRNAs were differentially expressed with a predominance of IGFBP-5. The onset of renal hypertrophy in STZ-induced diabetes was associated with a rapid and site-specific induction of IGFBP-1, -3, and -5 mRNAs. In contrast, basal expression of IGFBP-2, -4, and -6 mRNAs was not altered in diabetic rats. IGFBP-5 mRNA expression increased in diabetic glomeruli, cortical, and inner medullary peritubular interstitial cells at days 3, 7, and 14. Although normal glomeruli failed to express IGFBP-3, it was induced concomitantly with IGFBP-5 in diabetic glomeruli and cortical peritubular interstitial cells. IGFBP-1 mRNA levels also increased in cortical tubular cells at each time point tested. Peak induction of IGFBP-3 and -5 was observed at day 3, whereas IGFBP-1 was delayed until day 7. IGFBP-1, -3, and -5 mRNA levels declined by day 14, but remained persistently elevated above control. By immunoperoxidase staining, similar alterations in the pattern of IGFBP-3 and -5 protein expression were observed at each time point. The preferential and site-specific increase in IGFBP-1, -3, and -5 suggest that these IGFBPs may regulate the local autocrine and/or paracrine actions of IGF-I and contribute to the pathogenesis of the early manifestations of diabetic nephropathy.  相似文献   
70.
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