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   447537篇
  免费   41483篇
  国内免费   30235篇
耳鼻咽喉   3539篇
儿科学   6289篇
妇产科学   4593篇
基础医学   45258篇
口腔科学   7213篇
临床医学   61769篇
内科学   57168篇
皮肤病学   4991篇
神经病学   19659篇
特种医学   16582篇
外国民族医学   224篇
外科学   39696篇
综合类   90543篇
现状与发展   115篇
一般理论   31篇
预防医学   35875篇
眼科学   11712篇
药学   49193篇
  549篇
中国医学   31761篇
肿瘤学   32495篇
  2024年   2458篇
  2023年   6504篇
  2022年   16483篇
  2021年   20970篇
  2020年   17108篇
  2019年   13093篇
  2018年   13588篇
  2017年   13559篇
  2016年   12214篇
  2015年   19259篇
  2014年   24248篇
  2013年   23368篇
  2012年   34726篇
  2011年   38516篇
  2010年   27618篇
  2009年   23194篇
  2008年   27255篇
  2007年   26930篇
  2006年   25317篇
  2005年   23435篇
  2004年   15729篇
  2003年   14755篇
  2002年   11962篇
  2001年   10459篇
  2000年   9743篇
  1999年   8912篇
  1998年   5418篇
  1997年   5220篇
  1996年   4086篇
  1995年   3790篇
  1994年   3218篇
  1993年   2079篇
  1992年   2469篇
  1991年   2156篇
  1990年   1814篇
  1989年   1574篇
  1988年   1296篇
  1987年   1199篇
  1986年   974篇
  1985年   689篇
  1984年   382篇
  1983年   284篇
  1982年   155篇
  1981年   171篇
  1980年   116篇
  1979年   155篇
  1978年   73篇
  1977年   53篇
  1974年   42篇
  1972年   37篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
81.
82.
Penetrating craniocerebral firearm injuries remain one of the most lethal causes of all trauma and are common both in war or peace time. Data were reviewed for 4140 severely head-injured patients (Glasgow Coma Scale (GCS) scores 3-8) treated at Xi-Jing Hospital between 1973 and 1993; 51 of these patients had acute penetrating craniocerebral injuries caused by firearm missiles. These patients consisted of 46 males (90.2%) and 5 females (9.8%) ranging in age from 3 months to 48 years (median 22.4 years). The lesion types included 2 tangential wounds, 37 tubular wounds and 12 through-and-through wounds. All cases were urgent with the patients in severe and unstable states. After emergency treatment and operation, 5 cases died (9.8%). Follow up studies at three months showed that 23 cases (45.1%) had made a good recovery. Moderate disability, severe disability and vegetative states in this series were 29.4%, 13.7% and 2.0% respectively. Long term follow up studies indicated that 32 were able to resume their occupation. The principles for managing penetrating craniocerebral firearm injuries and suggestions for operation are discussed.  相似文献   
83.
Da-Nian Zhu, Long-Mei Xue, Peng Li. Effect of central muscarine receptor blockade. with DKJ-21 on the blood pressure and heart rote in stress-induced hypertensive rats.

The experiments were performed on Wistar or Sprague-Dawley rats of both sexes divided at random into stress and control groups. The rats in the stress groups were put into cages and subjected to electric foot-shocks and noises for 9-15 days, which caused an increase in blood pressure (BP) and heart rate (HR). In hypertensive rats DKJ-21 (4mg/lml) was injected intravenously (i.v.), and 0.5-1.0h after administration the BP and HR dropped from the high level to normotensive level. In normotensive rats, however, administration of DKJ-21 had no effect on BP or HR. In separate groups of normotensive rats, pretreatment of DKJ-21 (4 mg/l ml, i.v.) blocked the pressor and tachycardiac effect induced by microinjection of physostigmine (0.4μg/0.1 /μl/site), corticosterone (40μg/0.1μl/site) or aldosterone (40 μg/0.1 μl/site) into the rostral ventrolateral medulla (rVLM). Furthermore, DKJ-21 also attenuated the enhancement of the pressor response to stimulation of the defense area in the midbrain, which was induced by microinjection of drugs (mentioned above) into the rVLM. These results indicate that i.v. DKJ-21 can selectively block the muscarinic receptors in the rVLM in stress-induced hypertensive rats, which suggests that abnormal enhancement of cholinergic mechanism in the rVLM may be related to hypertensive effects of corticoids in this area.  相似文献   
84.
Management of hepatocellular carcinoma presenting as obstructive jaundice   总被引:8,自引:0,他引:8  
Eleven (3%) of 340 patients with hepatocellular carcinoma (HCC) presented with obstructive jaundice. The tumor extensively infiltrated the major bile ducts in eight patients. Jaundice was relieved by endoscopic endoprosthesis in four patients, nasobiliary drainage in two patients, percutaneous transhepatic stenting in one patient, and surgical intubation in one patient. The survival interval of these eight patients (mean +/- SD) was 35 +/- 20 days. Three patients had tumor fragments in the common bile ducts. In two patients, major hepatic resection was done after initial tube decomposition of the biliary system. One patient remained tumor-free on follow-up at 24 months, and the other patient had recurrent tumor detected on follow-up at 17 months after surgery. The tumor was irresectable in the third patient. Multiple surgical and endoscopic procedures kept the bile duct patent for 17 months before the patient died of the disease. Not all patients who present with obstructive jaundice due to HCC are terminally ill. With proper management, good palliation and occasional cure are possible.  相似文献   
85.
李钧  张泺 《眼科研究》1990,8(3):156-158
应用神经组织化学技术观察了兔角膜NA能神经及AchE阳性神经在角膜损伤后的再生,证实术后1月,两种神经均有再生轴突进入植片;术后3月可见交界区和植床内神经密度明显增加;同时,对术后两种神经再生的功能意义进行了讨论。  相似文献   
86.
血管内氧合器的研制   总被引:2,自引:0,他引:2  
为了探索呼吸辅助的新方法,我们采用国产聚丙烯中空纤维,自行设计、制造模具,研制出一种血管内氧合器。该氧合器是一个小的、细长的可经单侧股静脉或颈静脉切开,置入腔静脉内的装置。氧合器有效长度40cm,膜交换面积0.09m^2。经负压调节通过血管内氧合器的氧流量,以防止纤维破裂造成的血管内气栓的危险。一根双腔导气管使气体经同一静脉切开部位循环,气体经内芯管流经血管内氧合器尖端,然后经中空纤维束流出。目前  相似文献   
87.
本文探讨了ASA剂量与药效的关系及血ASA、SA药物浓度监测的临床意义,结果表明:(1)ASA剂量与6-keto-PGF_(1α)抑制率呈正相关(P<0.01),而与TXB_2及PAgR抑制率无相关性(P>0.1);(2)本文采用HPLC内标法同时测定血ASA和SA浓度,结果准确,方法简便;(3)当口服小剂量ASA防治CI时,监测血ASA和SA以调整ASA用药剂量的临床价值并非十分重要。  相似文献   
88.
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.
益气平喘丸的药理研究   总被引:7,自引:0,他引:7  
李美珠  钟伟新 《中成药》1992,14(11):28-29
本实验结果表明,益气平喘丸具有明显的平喘止咳祛痰作用,并能显著增加免疫低下小鼠的免疫器官重量及碳粒廓清速率,使正常大鼠血清皮质醇浓度显著升高及肾上腺内维C 含量明显降低。  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