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   93270篇
  免费   42348篇
  国内免费   505篇
耳鼻咽喉   1677篇
儿科学   4553篇
妇产科学   1130篇
基础医学   17602篇
口腔科学   5334篇
临床医学   14275篇
内科学   25962篇
皮肤病学   7596篇
神经病学   14234篇
特种医学   2675篇
外国民族医学   1篇
外科学   15671篇
综合类   1283篇
现状与发展   5篇
一般理论   25篇
预防医学   5143篇
眼科学   1912篇
药学   7120篇
  6篇
中国医学   1510篇
肿瘤学   8409篇
  2024年   31篇
  2023年   247篇
  2022年   556篇
  2021年   1948篇
  2020年   5463篇
  2019年   11241篇
  2018年   10536篇
  2017年   11784篇
  2016年   12434篇
  2015年   12498篇
  2014年   12490篇
  2013年   13057篇
  2012年   5274篇
  2011年   5276篇
  2010年   9650篇
  2009年   5805篇
  2008年   2922篇
  2007年   1714篇
  2006年   1771篇
  2005年   1522篇
  2004年   1399篇
  2003年   1305篇
  2002年   1368篇
  2001年   1235篇
  2000年   1126篇
  1999年   678篇
  1998年   170篇
  1997年   176篇
  1996年   154篇
  1995年   155篇
  1994年   111篇
  1993年   88篇
  1992年   228篇
  1991年   198篇
  1990年   180篇
  1989年   191篇
  1988年   142篇
  1987年   117篇
  1986年   97篇
  1985年   102篇
  1984年   83篇
  1983年   65篇
  1982年   39篇
  1981年   55篇
  1980年   43篇
  1979年   62篇
  1978年   47篇
  1977年   40篇
  1975年   28篇
  1974年   30篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
51.
52.
53.
The vascular anatomy of the pronator quadratus muscle and distal radius was studied in 24 cadaveric forearms by dissection under magnification and india ink and latex injection studies. The anterior interosseous artery divides into a muscular branch and a dorsal branch 1 cm to 3.5 cm from the proximal margin of the pronator quadratus muscle, and on its deep surface. Injection studies showed a rich periosteal plexus contributed by the anterior interosseous artery. Retrograde injection through the dorsal branch also showed good perfusion of the distal radius that was confirmed microscopically on bone sections. A muscle-bone graft from the anteromedial cortex of distal radius with an intact anterior interosseous artery has mobility of less than 2 cm. After ligating and dividing the anterior interosseous artery, blood supply to the distal radius bone flap relies on a retrograde flow and the bone flap could then be mobilized distally up to 4 to 6 cm.  相似文献   
54.
55.
Previously, we reported that transgenic mice overexpressing endothelin-1 in astrocytes showed more severe neurological deficits and increased infarct after transient focal ischemia. In those studies, we also observed increased level of aldose reductase (AR), the first and rate-limiting enzyme of the polyol pathway, which has been implicated in osmotic and oxidative stress. To further understand the involvement of the polyol pathway, the mice with deletion of enzymes in the polyol pathway, AR, and sorbitol dehydrogenase (SD), which is the second enzyme in this pathway, were challenged with similar cerebral ischemic injury. Deletion of AR-protected animals from severe neurological deficits and large infarct, whereas similar protection was not observed in mice with SD deficiency. Most interestingly, AR(-/-) brains showed lowered expression of transferrin and transferrin receptor with less iron deposition and nitrotyrosine accumulation. The protection against oxidative stress in AR(-/-) brain was also associated with less poly(adenosine diphosphate-ribose) polymerase (PARP) and caspase-3 activation. Pharmacological inhibition of AR by Fidarestat also protected animals against cerebral ischemic injury. These findings are the first to show that AR contributes to iron- and transferrin-related oxidative stress associated with cerebral ischemic injury, suggesting that inhibition of AR but not SD may have therapeutic potential against cerebral ischemic injury.  相似文献   
56.
57.
Frontal intracerebral haemorrhage (ICH) is a common result of cranial trauma. Outcome differences between bilateral and unilateral frontal ICH are not well studied but would be valuable to predict prognosis in clinical practice. Two aims are proposed in this study: first to compare the risk of developing delayed ICH after bilateral or unilateral frontal ICH, and second to determine the variables helpful to predict outcome according to the Glasgow Outcome Scale (GOS). Between January 1993 and December 1997, 694 consecutive patients with traumatic ICH were admitted to the Chang Gung Medical Center within 24 h of the trauma. Patients with ICH in sites other than the frontal lobes were excluded. A total of 161 cases (mean age 46.3+/-20.3 years), including 57 bilateral (mean age 52.5+/-18.7 years) and 104 unilateral (mean age 42.9+/-20.5 years) traumatic frontal ICH were studied. Twenty-eight of 57 patients (49%) with bifrontal ICH versus 17 of 104 patients (16%) with unilateral frontal ICH had a further, delayed ICH. In 42 of 45 patients (93%) with delayed ICH, this occurred within 5 days of the initial trauma. Multivariate logistic regression was used to select significant predictors of outcome. We found that delayed ICH (p<0.001), age (p=0.004) and mechanism of injury (p=0.001) explained the worse outcome in patients with bifrontal ICH. The best-fitting logistic regression model included three variables: delayed ICH (p=0.011), initial GCS (p=0.023), and a sum score of clinical and radiological variables (p=0.003). Bifrontal ICH tended to occur in older patients after a fall and was associated with a higher risk of developing delayed ICH or brain stem compression compared to unilateral ICH damage. Using these three variables - delayed ICH, initial GCS, and the sum score - in a logistical regression model is useful to predict outcome in patients with traumatic frontal ICH and may aid patient management.  相似文献   
58.
关木通引起慢性间质性肾炎7例报告   总被引:3,自引:0,他引:3  
目的 观察关木通所致慢性肾损伤的临床和病理改变特点。方法 本组 7例中 ,男 5例 ,女 2例。 3例服关木通汤药 ,4例服含关木通成药。分析服用时间、累积总量与肾损害首发症状及症状出现时间、肾功能和肾病理改变的关系。结果 汤药组 :服药时间平均 3 3 3个月 ,累积总量平均 82 9 3 g ,首发症状为乏力 3例 ,夜尿增多 2例 ,平均时间为 8 3个月 ,Cr平均 40 2 μmol/L。肾病理 :3例均为重度寡细胞性肾间质纤维化 ,肾小管广泛萎缩。成药组 :服药时间平均 7 5个月 ,累积总量平均 13 6g ,乏力 3例 ,夜尿增多 1例 ,恶心呕吐、头痛头晕 1例 ,平均18 8个月 ,Cr 3 62 8μmol/L。肾病理为重度寡细胞性间质纤维化和灶状纤维化各 2例 ,肾小管灶状萎缩 3例 ,广泛萎缩 1例。结论 汤药组关木通积累大 ,发病时间早 ,肾病理改变重。提示关木通所致肾损其临床表现、病理改变与服用关木通时间、剂量相关。  相似文献   
59.
60.
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