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   978476篇
  免费   69317篇
  国内免费   1484篇
耳鼻咽喉   13534篇
儿科学   25701篇
妇产科学   24085篇
基础医学   138491篇
口腔科学   29038篇
临床医学   85483篇
内科学   193055篇
皮肤病学   20061篇
神经病学   76536篇
特种医学   38740篇
外国民族医学   80篇
外科学   160061篇
综合类   18503篇
现状与发展   1篇
一般理论   281篇
预防医学   64710篇
眼科学   22116篇
药学   75464篇
  3篇
中国医学   2199篇
肿瘤学   61135篇
  2018年   10149篇
  2017年   7894篇
  2016年   8667篇
  2015年   9925篇
  2014年   13615篇
  2013年   19628篇
  2012年   27501篇
  2011年   28614篇
  2010年   16807篇
  2009年   15980篇
  2008年   27729篇
  2007年   29022篇
  2006年   29786篇
  2005年   28646篇
  2004年   27633篇
  2003年   26493篇
  2002年   25794篇
  2001年   55126篇
  2000年   56828篇
  1999年   47363篇
  1998年   11275篇
  1997年   9922篇
  1996年   9934篇
  1995年   9268篇
  1994年   8599篇
  1993年   7865篇
  1992年   35729篇
  1991年   34147篇
  1990年   32943篇
  1989年   32052篇
  1988年   29189篇
  1987年   28432篇
  1986年   26454篇
  1985年   25314篇
  1984年   18024篇
  1983年   15327篇
  1982年   8010篇
  1981年   6958篇
  1979年   15893篇
  1978年   10687篇
  1977年   9127篇
  1976年   7931篇
  1975年   8672篇
  1974年   10526篇
  1973年   9907篇
  1972年   9388篇
  1971年   8880篇
  1970年   8453篇
  1969年   7939篇
  1968年   7214篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
Pemedolac Na, 1-ethyl-1,3,4,9-tetrahydro-4-(phenylmethyl)-pyrano [3,4-b] indole-1-acetic acid sodium salt, exhibited equipotent analgesic effects after oral, iv, and im administration, suggesting that it is well absorbed. In mouse writhing models, the ED50 values ranged from 0.3 mg (0.81 μmol)/kg (vs. acetylcholine) to 4.3 mg (11.6 μmol)/kg (vs. paraphenylbenzoquinone [PBQ]). In the rat Randall-Selitto model, the ED50 o the compound was approximately 0.001 mg (2.7 nmol)/kg, with a flat dose response curve. The peak effects lasted for 7–9 h, 10–18 h, and 5 h following oral, im, and iv injections, respectively. Intracerebroventricular (i.c.v.) injections of pemedolac Na inhibited the PBQ-induced writing in mice with an ED50 of 43.5 μg (0.12 μmol)/mouse, and this effect was not antagonized by naloxone. It was inactive in the hot plate and tail flick tests, demonstrating that pemedolac Na does not act via an opiate mechanism. These results indicate that pemedolac Na is a viable parenteral and oral analgesic, typified by high analgesic potency, a rapid onset and long duration of action, and an extremely wide safety index. © Wiley-Liss, Inc.  相似文献   
992.
A case is reported of rapid onset concomitant pulmonary infection withNocardia andAspergillus fumigatus in a patient six weeks after the institution of immunosuppressive therapy for renal vasculitis. Pulmonary lesions completely resolved on treatment with a combination of imipenem, cotrimoxazole and a prolonged course of itraconazole.  相似文献   
993.
In a group of 182 patients who underwent surgical treatment for aortoiliac occlusions 172 had to be subjected to intraoperative distal angiography. The operative tactics in this case was determined by the degree of affection of the peripheral vessels and the character of collateral circulation, which were appraised from the findings of the operative angiograms. According to this, all patients were divided into 4 groups. Two patients developed complications linked with faulty appraisal of the drainage paths.  相似文献   
994.
C T Black  P J Hennessey  R J Andrassy 《The Journal of trauma》1990,30(7):830-2; discussion 832-3
Hyperglycemia accompanies a myriad of clinical conditions and causes an acceleration in the nonenzymatic glycosylation (NEG) of proteins. Since many proteins lose function when glycosylated, we assessed the effect of hyperglycemia on the function of immunoglobulin G. Twenty newborn Sprague-Dawley rats underwent splenectomy and 20, splenic mobilization alone. After 3 weeks, all animals received an intraperitoneal injection of Streptococcus pneumoniae. Twelve hours later, ten animals from each group received either control (CIG) or glycosylated (GIG) human immunoglobulin (0.3 gm/kg) intraperitoneally. Asplenic animals receiving GIG lived 28.5 hours vs. 49.6 hours for those receiving CIG (p less than 0.0001). Animals with spleens receiving GIG lived 48.2 hours vs. 51.7 hours for those receiving CIG (p = 0.03). Short-term glycosylation of immunoglobulin causes its inactivation. This may contribute to the increased risk of infection noted in hyperglycemic animals.  相似文献   
995.
Seminal culture and leucocyte elastase measurements were undertaken on samples from 30 men attending an infertility clinic. Elastase levels over 1000 ng ml-1 were obtained in 14 men and positive bacterial culture in 11 men, but there was no correlation between these two sets of measurements. While granulocyte elastase measurement in semen may reflect inflammation, our study suggests that it cannot be used as a simple marker of infection particularly in a population such as ours where the prevalence of prostatitis and genital infection is low.  相似文献   
996.
The United States is one of the few economically developed nations without a national policy supporting children and their families. This paper suggests that the United States has a unique national ideology, based on the “Calvinistic Ethic,” which results in opposition to not only social programs for children and families, but to all government supported welfare programs. Such an ethic is not found in European countries. Finally, since the United States does not have a national family policy, millions of children and their families go without health care, lack social services, and suffer from inadequate economic supports.  相似文献   
997.
Bilateral horizontal gaze palsies are rare. In this case report, we present a 28-year-old woman with bilateral horizontal gaze palsies due to involvement of both paramedian pontine reticular formations (PPRFs) by multiple sclerosis (MS) plaques.  相似文献   
998.
We used the laser flowmeter to measure and compare the effect of nitroglycerin (TNG), trimetaphan (TMP) and prostaglandin E1 (PGE1) on the blood flow of operating field during hypotension induced by each drug. The study was done in 33 patients (TNG:13, TMP:13 and PGE1:7) anesthetized with modified NLA who underwent radical mastectomy. We put the probe of the laser flowmeter on the skin of the opposite breast to the operating field and measured the skin blood flow change. Measurements were made before and during hypotension induced by each drug. TMP-induced hypotension decreased blood flow significantly (P less than 0.05), but TNG and PGE1 had no significant effect. Intraoperative blood losses of TNG and PGE1 group were not significantly larger than that of TMP group. From this study we conclude that TNG, TMP and PGE1 can dry the operating field and decrease intraoperative blood loss similarly. Therefore we should choose the drugs to induce hypotension considering the effect of the drug on blood flow of the important organs and each patient's complications.  相似文献   
999.
A 86-year-old man was admitted to our hospital because of swallowing disturbance and deterioration of consciousness. He had been aware of hearing disturbance on the right side for twelve months. Computed tomography (CT) scan demonstrated an inhomogeneous hyperdense mass lesion, 3.2 X 2.3 cm in size, at the right cerebello-pontine angle, and ventricular enlargement with intraventricular hemorrhage. Skull tomogram revealed destructive enlargement of the right jugular foramen. The angiogram showed avascular mass with elevation of anterior inferior cerebellar artery, and downward shift of posterior inferior cerebellar artery. Operative and histological findings were compatible with glossopharyngeal neurinoma of Antoni type A dominance. This tumor had numerous abnormal vessels probably causing massive hemorrhage. Only fifteen cases of intracranial neurinoma with symptomatic hemorrhage have been reported in the world literature. This case is reported as the sixteenth one and the first glossopharyngeal neurinoma among them. Possible etiology of such hemorrhage is discussed.  相似文献   
1000.
The dynamic and functional state of soda lime can be more precisely assessed by measuring changes in wall temperatures of the absorption chambers rather than observing color change of the soda lime granules. We demonstrated in this report that the liquid crystal thermometer is an inexpensive and reliable measuring device for this purpose.  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