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   184931篇
  免费   17804篇
  国内免费   10674篇
耳鼻咽喉   1621篇
儿科学   2482篇
妇产科学   2494篇
基础医学   20456篇
口腔科学   3959篇
临床医学   23065篇
内科学   25938篇
皮肤病学   2593篇
神经病学   8426篇
特种医学   6232篇
外国民族医学   50篇
外科学   17543篇
综合类   33109篇
现状与发展   41篇
一般理论   13篇
预防医学   15661篇
眼科学   5001篇
药学   20068篇
  233篇
中国医学   11475篇
肿瘤学   12949篇
  2024年   549篇
  2023年   2246篇
  2022年   5508篇
  2021年   7058篇
  2020年   5710篇
  2019年   4577篇
  2018年   5152篇
  2017年   5363篇
  2016年   4629篇
  2015年   7250篇
  2014年   8991篇
  2013年   9508篇
  2012年   14005篇
  2011年   14611篇
  2010年   10895篇
  2009年   9252篇
  2008年   10644篇
  2007年   10432篇
  2006年   9294篇
  2005年   8137篇
  2004年   5777篇
  2003年   5406篇
  2002年   4592篇
  2001年   7169篇
  2000年   6641篇
  1999年   5531篇
  1998年   2321篇
  1997年   1975篇
  1996年   1347篇
  1995年   1128篇
  1994年   1035篇
  1993年   750篇
  1992年   2233篇
  1991年   1959篇
  1990年   1777篇
  1989年   1675篇
  1988年   1478篇
  1987年   1345篇
  1986年   1164篇
  1985年   977篇
  1984年   625篇
  1983年   500篇
  1982年   259篇
  1981年   190篇
  1980年   147篇
  1979年   291篇
  1978年   79篇
  1974年   78篇
  1973年   100篇
  1972年   71篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
81.
报道并分析20例小儿糖尿病患儿的临床资料及血胰岛细胞抗体(ICA)及胰岛素自身抗体(IAA)的测定资料。在20例患儿中,临床表现多不典型。在酮症酸中毒的治疗中小剂量胰岛素疗法方法简便,安全可靠,并发症少。本组患儿ICA阳性率55%,IAA阳性率30%,经卡方检验均显著高于对照组,推测病毒感染引起自身免疫反应,产生ICA及IAA而致本病发生。  相似文献   
82.
M Y Fan  Z P Lum  X W Fu  L Levesque  I T Tai  A M Sun 《Diabetes》1990,39(4):519-522
Prolonged survival of pancreatic islet allografts implanted in diabetic BB rats was achieved by encapsulation of individual islets in a protective biocompatible alginate-polylysine-alginate membrane without immunosuppression. Intraperitoneal transplantation of the encapsulated islets reversed the diabetic state of the recipients within 3 days and maintained normoglycemia for 190 days. Normal body weight and urine volume were maintained during this period, and no cataracts were detected in the transplant recipients. In contrast, control rats receiving transplants of unencapsulated islets experienced normoglycemia for less than 2 wk. These results demonstrated that microencapsulation can protect allografted islets from both graft rejection and autoimmune destruction without immunosuppression in an animal model that mimics human insulin-dependent diabetes.  相似文献   
83.
戴慧芬教授治疗痛经的经验   总被引:2,自引:0,他引:2  
介绍了戴彗芬教授应用逍遥散、当归调经汤、温经汤、和经止痛汤,当归芍药散、当归四逆加吴萸、生姜汤、血府逐瘀汤治疗痛经的经验。  相似文献   
84.
Two unique forms of cytochrome P-450 (P-450), designated NMa and NMb, were recently isolated in this laboratory from nasal microsomes of rabbits. In the present study, polyclonal antibodies to the purified nasal cytochromes were prepared. Immunochemical analysis with specific rabbit anti-NMa and sheep anti-NMb antibodies indicated that P-450 isozymes identical to or having a high structural homology with NMa are present in both olfactory and respiratory mucosa, as well as in liver, but NMb was detected only in the olfactory mucosa. Neither form was detected in other tissues examined, including brain, esophageal mucosa, heart, intestinal mucosa, kidney, and lung. The specific occurrence of NMb in the olfactory mucosa was further substantiated by the detection and specific inhibition by anti-NMb of the formation of unique NMb-dependent metabolites of testosterone in olfactory microsomes but not in microsomes from liver or respiratory mucosa. Similar experiments with antibodies to previously purified rabbit hepatic P-450 isozymes indicated that not all of the hepatic cytochromes are expressed in the nasal tissues. Thus, P-450 isozymes structurally homologous to hepatic forms 2, 3a, and 4, but not 3b and 6, were found in the olfactory mucosa. On the other hand, only form 2 was detected in the respiratory mucosa. Immunoquantitation experiments revealed that NMa and NMb are the major P-450 forms in olfactory microsomes, whereas NMa and P-450 form 2 (or its homolog) constitute the major portion of the respiratory nasal microsomal P-450. The level of NMa in the liver is relatively low, accounting for less than 3% of total microsomal P-450 in this tissue. In addition, evidence is provided that NMa is the major catalyst in the dealkylation of two nasal carcinogens, hexamethylphosphoramide and phenacetin, in both olfactory and respiratory nasal microsomes.  相似文献   
85.
It is well established that painful distension of hollow viscera such as the oesophagus can evoke a reflex tachycardia and pressor response; however, the nature of the oesophageal afferent pathway(s) remains controversial. This study investigated the afferent arc which mediates these reflex cardiovascular changes in the decerebrate rat. In addition, the effect of oesophageal distension on the respiratory activity of the costal diaphragm was studied. Focal distension of the oesophagus (volume of 0.3 ml applied for 10 s) just above the diaphragmatic hiatus evoked a reproducible pressor response and tachycardia in the decerebrate rat. Respiration was transiently inhibited at the beginning of oesophageal distension and prior to the rise in blood pressure. Neuromuscular blockade with the nicotinic acetylcholine receptor blocker alpha-bungarotoxin (140 microg bolus) had no effect on the magnitude of the cardiovascular response. Therefore the efferent supply to the striated muscle of the rat oesophagus was not essential in mediating this reflex. Signal averaging of the mean blood pressure response showed that neither selective ablation of oesophageal spinal afferents nor bilateral vagotomy altered the early trajectory of the pressure response. Bilateral vagotomy reduced the peak magnitude of the response to sustained oesophageal distension. In contrast, selective removal of spinal afferents had no effect on the response. Ablation of both neural pathways was essential to abolish the reflex cardiovascular and respiratory responses. It can be concluded that both vagal and spinal afferent pathways are utilised in the reflex cardiorespiratory response to painful oesophageal distension. Although ablation of one neural pathway had no effect on the response it was still implicated in the reflex, since ablation of both pathways was necessary to prevent the cardiorespiratory changes. This study emphasises the need for caution when inferences are made concerning single selective ablations of multiply innervated organs.  相似文献   
86.
87.
Measurements of the fetal eyeball and its pattern of growth   总被引:1,自引:0,他引:1  
  相似文献   
88.
89.
90.
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