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   13809篇
  免费   737篇
  国内免费   42篇
耳鼻咽喉   134篇
儿科学   811篇
妇产科学   306篇
基础医学   1441篇
口腔科学   298篇
临床医学   884篇
内科学   2905篇
皮肤病学   369篇
神经病学   766篇
特种医学   406篇
外国民族医学   1篇
外科学   2260篇
综合类   340篇
一般理论   11篇
预防医学   538篇
眼科学   640篇
药学   1343篇
中国医学   55篇
肿瘤学   1080篇
  2023年   99篇
  2022年   210篇
  2021年   516篇
  2020年   243篇
  2019年   356篇
  2018年   424篇
  2017年   338篇
  2016年   401篇
  2015年   404篇
  2014年   552篇
  2013年   743篇
  2012年   1040篇
  2011年   1100篇
  2010年   609篇
  2009年   474篇
  2008年   768篇
  2007年   736篇
  2006年   600篇
  2005年   606篇
  2004年   554篇
  2003年   458篇
  2002年   421篇
  2001年   313篇
  2000年   300篇
  1999年   256篇
  1998年   108篇
  1997年   71篇
  1996年   87篇
  1995年   72篇
  1994年   54篇
  1993年   48篇
  1992年   122篇
  1991年   161篇
  1990年   130篇
  1989年   111篇
  1988年   107篇
  1987年   76篇
  1986年   85篇
  1985年   89篇
  1984年   65篇
  1983年   68篇
  1979年   66篇
  1978年   44篇
  1977年   35篇
  1975年   34篇
  1973年   38篇
  1972年   41篇
  1971年   44篇
  1970年   33篇
  1968年   44篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
2.
3.

Objective

Hypertonic saline (HTS) has potent immune and vascular effects. We assessed recipient pretreatment with HTS on allograft function in a porcine model of heart transplantation and hypothesized that HTS infusion would limit endothelial and left ventricular (LV) dysfunction following transplantation.

Methods

Heart transplants were performed after 6 hours of cold ischemic storage. Recipient pigs were randomized to treatment with or without HTS (7.5% NaCl) before cardiopulmonary bypass (CPB). Using a myograft apparatus, coronary artery endothelial-dependent (Edep) and -independent (Eind) relaxation was assessed. LV performance was determined using pressure-volume loop analysis. Pulmonary interleukin (IL)-2, IL-6, and tumor necrosis factor (TNF)-α expression was measured.

Results

Weaning from CPB and LV performance after transplantation were improved in HTS-treated animals. Successful weaning from CPB was greater in the HTS-treated hearts (8 of 8 vs 2 of 8; P < .05). Mean LV functional recovery was improved in the HTS-treated animals, as assessed by preload recruitable stroke work (65 ± 10% vs 27 ± 10%; P < .001) and end-systolic elastance (55 ± 7% vs 37 ± 4%; P < .001). Treatment with HTS resulted in improved Edep (mean maximum elastance [Emax], 56 ± 5% vs 37 ± 7%; P < .001) and Eind (mean Emax%, 77 ± 6% vs 52 ± 4%; P < .001) vasorelaxation compared with control. Pulmonary expression of IL-2, IL-6, and TNF-α increased following transplantation, whereas HTS therapy attenuated IL production (P < .001). Transplantation increased plasma TNF-α levels and LV TNF-α expression, whereas HTS prevented this up-regulation (P < .001).

Conclusions

Recipient HTS pretreatment preserves allograft vasomotor and LV function, and HTS therapy limits CPB-induced injury. HTS may be a novel recipient intervention to prevent graft dysfunction.  相似文献   
4.
5.
Intussusception is a very rare cause of intestinal obstruction in neonates. It is of extremely rare occurrence among premature neonates. We present a case of 11-day-old premature neonate who presented with abdominal distension, intolerance to feeds, vomiting, significant bilious aspirate and bleeding per rectum. The initial diagnosis of necrotizing enterocolitis (NEC) led to a delay in the diagnosis. On exploratory laparotomy, it turned out to be a case of ileo-colic intussusception with Meckel''s diverticulum as a lead point. This site of intussusception (ileo-colic) and presence of a lead point among premature neonate is of exceedingly rare occurrence and very few such cases have been reported.In this article, the published work about clinical features and management on intussusceptions in premature neonates has been reviewed. The authors intend to highlight the difficulty in distinguishing the NEC and intussusception. Subtle clinical and radiological features which can help in differentiating the two conditions have been emphasized. This can avoid the delay in diagnosis and management which can prove critical. High index of suspicion with timely intervention is the key for optimizing outcome. A diagnosis of intussusception should always be considered in any preterm infant with suspected NEC.  相似文献   
6.
7.
Functional recovery, the goal of treatment, has long been overlooked in the assessment of effectiveness of pharmacological treatments. However, with the recent shift in paradigm, from syndromal–symptomatic recovery to functional recovery, there appears to be a new interest in the definition and evaluation of functional recovery. Since functional recovery lags symptomatic recovery, sometimes by months or years, the attainment of functional recovery will be determined by both efficacy and long-term compliance. Quetiapine, due to its efficacy in both mania and depression, and effect on cognition may lead to improved functioning in patients with bipolar disorder.  相似文献   
8.
For patients who receive a liver transplant (LTX) for alcoholic liver disease (ALD), investigators are focusing beyond survival to determine specific alcohol use outcomes. Studies suggest the use of alcohol ranges from 8 to 22% for the first post-transplant year with cumulative rates reaching 30 to 40% by 5 years following transplantation. Yet while investigators are interested in determining specific rates of alcohol use and predictors of use, only three studies since 1990 have been prospective. In 1998, we began a prospective study of post-LTX alcohol consumption in ALD recipients using multiple repeated measures of alcohol use. After 5 years of follow-up, we found that 22% had used any alcohol by the first year and 42% had a drink by 5 years. By 5 years, 26% drank at a heavier use (binge) pattern and 20% drank in a frequent pattern. In a univariate model, predictors of alcohol use included pre-transplant length of sobriety, a diagnosis of alcohol dependence, a history of other substance use, and prior alcohol rehabilitation.  相似文献   
9.
10.
Circulating immune complexes in pre-eclampsia.   总被引:3,自引:0,他引:3  
Serum samples from 20 non-pregnant women, 30 women with normal pregnancy and 50 women with pregnancy associated with pre-eclampsia were tested for circulating immune complexes using the polyethyleneglycol precipitation method. A highly significant positive correlation was found between circulating immune complexes and severe pre-eclampsia (BP greater than 140/90 mm Hg, albuminuria greater than 0.25 g/l). In contrast to this the difference in immune complex levels between non-pregnant subject, normal pregnancy cases and patients with mild pre-eclampsia was not statistically significant. A significant positive correlation was found between the level of circulating immune complexes and the severity of albuminuria. These findings suggest that circulating immune complexes, though not seeming to play an aetiological role in pre-eclampsia may very well be involved in its pathogenesis.  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