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   184431篇
  免费   17484篇
  国内免费   11920篇
耳鼻咽喉   1659篇
儿科学   1957篇
妇产科学   2441篇
基础医学   22159篇
口腔科学   3313篇
临床医学   24172篇
内科学   26968篇
皮肤病学   2240篇
神经病学   9692篇
特种医学   6517篇
外国民族医学   102篇
外科学   18816篇
综合类   29884篇
现状与发展   39篇
一般理论   22篇
预防医学   12369篇
眼科学   4812篇
药学   19923篇
  192篇
中国医学   11080篇
肿瘤学   15478篇
  2024年   738篇
  2023年   3016篇
  2022年   7868篇
  2021年   9898篇
  2020年   7432篇
  2019年   6406篇
  2018年   6690篇
  2017年   6143篇
  2016年   5743篇
  2015年   8809篇
  2014年   10706篇
  2013年   9884篇
  2012年   14414篇
  2011年   15563篇
  2010年   9928篇
  2009年   7652篇
  2008年   10165篇
  2007年   9630篇
  2006年   9246篇
  2005年   8971篇
  2004年   5767篇
  2003年   5207篇
  2002年   4330篇
  2001年   3643篇
  2000年   3843篇
  1999年   3893篇
  1998年   2316篇
  1997年   2371篇
  1996年   1797篇
  1995年   1747篇
  1994年   1531篇
  1993年   920篇
  1992年   1300篇
  1991年   1124篇
  1990年   900篇
  1989年   851篇
  1988年   766篇
  1987年   629篇
  1986年   461篇
  1985年   397篇
  1984年   190篇
  1983年   162篇
  1982年   93篇
  1981年   123篇
  1980年   79篇
  1979年   109篇
  1978年   52篇
  1977年   51篇
  1976年   43篇
  1974年   47篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
81.
82.
83.
临床输液监控系统的设计   总被引:5,自引:0,他引:5  
本文针对临床输液过程中出现的漏、停、输液速度改变等各种问题,讨论了一由单台微机和多个单片机通讯实现的多床输液自动监控、自动反应、自动报答系统的可行性,并给出了主要部分的硬件、软件设计方法。  相似文献   
84.
用分光比色法测定血清α-L-岩藻糖苷酶(AFU),研究其对36例原发性肝癌(PHC)、30例肝硬化(LC)、16例转移性肝癌(MC)、11例良性肝脏占位性病变(BSOL)、22例慢性肝炎(CH)和20例胃肠道恶性肿瘤(EMT)患者的临床应用价值。在肝脏占位性病变组中对AFU,AFP和α_1AT进行比较研究。结果表明:PHC组血清AFU活力显著高于其余各组,AFU,AFP和α_1AT对PHC诊断敏感性分别为75%,61.1%和66.7%,可靠性分别为81.7%,83.9%和65.6%,三项指标联测则PHC诊断阳性率可提高到91.7%。AFU活力与PHC肿瘤大小、AFP含量无相关,与α_1AT呈正相关。本文资料表明:AFU可作为PHC血清标志物,对AFP阴性病例尤有价值。  相似文献   
85.
86.
There is a growing body of evidence that the cytokine, tumor necrosis factor-α (TNF-ga), plays an important role in the development of hepatic ischemia/reperfusion injury. We found that the immunosuppressants, cyclosporine-A (CsA), azathioprine, and FK506, have protective effects on such injury. The purpose of the present study was to elucidate mechanisms involved in these beneficial effects of the immunosuppressant, CsA, on liver injury following cold preservation and transplantation, with special reference to the suppression of TNF-α release. Rat livers were stored in Euro-Collins solution (EC) at 4°C for 6h and orthotopically transplanted. The animals allotted to two groups: group A (untreated controls) and group B (CsA pretreatment of recipients). CsA (10 mg/kg, p.o.) was given for 3 consecutive days preoperatively. CsA pretreatment of the recipients significantly improved the 2-week survival rate (0/6 for group A, 3/6 for group B;P<0.05) and this was associated with a significant decrease in serum TNF-α levels 2h posttransplantation (group A, 69.8±15.7 pg/ml; group B, 22.8±6.8; mean±SEM;n=12 each;P<0.05) and amelioration of sinusoidal endothelial injury, assessed by electron microscopy. Plasma endotoxin levels following reperfusion of the grafts were not altered by the CsA therapy. Morphologically, CsA pretreatment of the recipients did not alter activation of Kupffer cells. CsA pretreatment of the recipient aids in preventing cold preservation/reperfusion injury of the liver graft, possibly by modulating effects of TNF-α.  相似文献   
87.
Immunology     
A selection of interesting papers that were published in the two months before our press date in major journals most likely to report significant results in immunology.  相似文献   
88.
我科自1981年3月至1991年12月应用吻合器行中、下段直肠癌切除术67例,同期发生吻合口漏10例(149%)。本文分析了吻合口漏发生的因素。病变部位、病灶范围、术中操作技术、术前肠道灌洗以及术后骶前引流是影响吻合口漏的重要因素。本文总结了吻合口漏的治疗方法,提倡保守治疗,或加作暂时性横结肠造口术。  相似文献   
89.
From July 1989, to June 1996, 160 patients with congenital bile duct dilatation (CBD) were treated at our institution. The incidence of CBD at our institution has increased annually. In approximately 90% of patients with CBD there was associated anomalous arrangement of the pancreaticobiliary ductal system, and we concluded that this was one of the main causes of CBD. Pediatric endoscopic retrograde cholangiopancreatography was first introduced to China in 1989, and has been successfully performed in 90.2% of 92 patients at our institution. We found that age at diagnosis was closely related to the subtype, complications, and mortality of CBD. The subtype also correlated with the presenting symptoms. One hundred and forty-seven of the 160 patients underwent surgery. Of these 147 patients, 136 (92.5%) were cured with normal liver function and 9 (6.1%) improved with liver impairment. Two patients died, one of postoperative pneumonia and one of liver failure. We conclude that early radical surgery and careful postoperative follow-up are essential in the prevention of CBD complications such as cholangitis, pancreatitis, biliary stones, and development of carcinoma. This article is based on a special lecture delivered before the 19th meeting of the Japanese Society of Pancreatico-biliary Maljunction, on September 14, 1996, in Tokyo  相似文献   
90.
Cells with natural killer activity (NK) may play an important role in host defence against tumour cells. The lytic function of NK cells is very sensitive to hyperthermic inactivation. However, cells with NK activity isolated from rat spleen and exposed to 41-42.5 degrees C for 30 min could partially recover their cytotoxic activity after incubation at 37 degrees C. The recovered cytotoxicity was still NK-specific, as it only resulted in the lysis of YAC-1 sensitive targets, and could not lyse NK-resistant P815 mastocytoma cells. Conjugate formation assay using NK cells labelled with specific monoclonal antibody (mAb) 3.2.3 indicated that the binding of NK cells to targets was not significantly affected by heat treatment. Compared to controls, however, microtubule organizing centre (MTOC) reorientation towards the region of intercellular contact was reduced by 40% in heated effector cells. This was accompanied by a greater inhibition (62-77%) of NK lytic activity. Kinetic analysis indicated that MTOC reorientation capacity recovered following incubation at 37 degrees C. MTOC recovery was maximal 4 h after treatment whereas that of lytic activity peaked at 6 h. These data indicate that NK cells recover NK-specific lytic activity after heat inactivation. Moreover, our study demonstrates that hyperthermia interferes with post-binding MTOC reorientation, and further supports a role for microtubule in secretory processes involved in NK-mediated cytolysis.  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