全文获取类型
收费全文 | 116758篇 |
免费 | 11870篇 |
国内免费 | 7762篇 |
专业分类
耳鼻咽喉 | 950篇 |
儿科学 | 1504篇 |
妇产科学 | 775篇 |
基础医学 | 10294篇 |
口腔科学 | 2029篇 |
临床医学 | 14362篇 |
内科学 | 13462篇 |
皮肤病学 | 1090篇 |
神经病学 | 4663篇 |
特种医学 | 4689篇 |
外国民族医学 | 39篇 |
外科学 | 11731篇 |
综合类 | 26898篇 |
现状与发展 | 29篇 |
一般理论 | 16篇 |
预防医学 | 11171篇 |
眼科学 | 1888篇 |
药学 | 13226篇 |
161篇 | |
中国医学 | 9282篇 |
肿瘤学 | 8131篇 |
出版年
2025年 | 26篇 |
2024年 | 1639篇 |
2023年 | 2152篇 |
2022年 | 4351篇 |
2021年 | 5298篇 |
2020年 | 4649篇 |
2019年 | 3262篇 |
2018年 | 3303篇 |
2017年 | 3533篇 |
2016年 | 3019篇 |
2015年 | 5113篇 |
2014年 | 6397篇 |
2013年 | 6850篇 |
2012年 | 10011篇 |
2011年 | 10986篇 |
2010年 | 8378篇 |
2009年 | 7256篇 |
2008年 | 7860篇 |
2007年 | 7777篇 |
2006年 | 6877篇 |
2005年 | 5919篇 |
2004年 | 4119篇 |
2003年 | 3636篇 |
2002年 | 3039篇 |
2001年 | 2439篇 |
2000年 | 2079篇 |
1999年 | 1406篇 |
1998年 | 816篇 |
1997年 | 776篇 |
1996年 | 606篇 |
1995年 | 537篇 |
1994年 | 415篇 |
1993年 | 307篇 |
1992年 | 256篇 |
1991年 | 207篇 |
1990年 | 195篇 |
1989年 | 184篇 |
1988年 | 142篇 |
1987年 | 138篇 |
1986年 | 111篇 |
1985年 | 97篇 |
1984年 | 52篇 |
1983年 | 35篇 |
1982年 | 30篇 |
1981年 | 24篇 |
1980年 | 16篇 |
1979年 | 18篇 |
1978年 | 7篇 |
1973年 | 5篇 |
1972年 | 6篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
31.
32.
Cerebral Cortical Aquaporin-4 Expression in Brain Edema following Cardiac Arrest in Rats 总被引:14,自引:0,他引:14
Feng Xiao MD MS Thomas C. Arnold MD Shu Zhang MD Carlos Brown J. Steven Alexander PhD Donna L. Carden MD Steven A. Conrad MD PhD 《Academic emergency medicine》2004,11(10):1001-1007
OBJECTIVES: Brain edema occurs following clinical as well as experimental cardiac arrest (CA) and predicts a poor neurologic outcome. The objective of this study was to determine the expression of cerebral cortex aquaporin (AQP)-4, a member of a family of membrane water-channel proteins, in brain edema formation following normothermic or hypothermic CA. METHODS: Twenty-four rats were subjected to time-matched normothermic (N-Sham, 37.5 degrees C +/- 0.5 degrees C, n = 6) or hypothermic (H-Sham, 34 degrees C +/- 0.5 degrees C, n = 6) sham experiments and normothermic (N-CA, n = 6) or hypothermic (H-CA, n = 6) CA induced by asphyxiation for 8 minutes. Hypothermia was induced before CA. The animals were resuscitated with cardiopulmonary resuscitation, ventilation, and epinephrine administration. Brain edema was determined by brain wet-to-dry weight ratio at one hour of resuscitation. AQP4 immunoactivity in the cerebral cortex was determined using immunohistochemical staining and was semiquantified as an intensity of staining with an automated cell imaging system. RESULTS: Mild hypothermia in the sham experiments did not alter cerebral cortex AQP4 immunoactivity (mean +/- SD) (55.0 +/- 3.7 in H-Sham vs. 53.3 +/- 1.7 in N-Sham, p > 0.05). N-CA resulted in a significant increase in AQP4 immunoactivity (61.8 +/- 4.5) compared with N-Sham (p = 0.01) and H-Sham (p = 0.03). H-CA attenuated AQP4 compared with N-CA (53.4 +/- 1.3, p = 0.01). Brain wet-to-dry weight ratios were 4.41 +/- 0.07 in N-Sham, 4.40 +/- 0.08 in H-Sham (p > 0.05 vs. N-Sham), 4.55 +/- 0.04 in N-CA (p = 0.004 vs. N-Sham; p = 0.005 vs. H-Sham), and 4.43 +/- 0.09 in H-CA (p = 0.02 vs. N-CA; p > 0.05 vs. N-Sham and H-Sham). CONCLUSIONS: Cerebral cortical AQP4 expression is up-regulated after normothermic CA, which is attenuated by hypothermia induced before CA. 相似文献
33.
在制备了两个Cell Ⅰ-Hep Ⅱ 双结构域重组FN多肽(CH50和CH56)的基础上,研究其抑制肿瘤细胞浸润能力的作用。两个多肽的结构差异是CH50中删除了Cell I和HepⅡ之间的Ⅲ-11和ED-A结构顺序。CH50(ED_(50)为30.2 nmol/L)结合细胞的能力略高于CH56(ED_(50)为45.4 nmol/L)。两种多肽均可显著抑制黑色素瘤B16/F1细胞结合层粘素的能力,抑制作用相同。在体内肿瘤浸润抑制试验中,两种多肽均可显著抑制癌细胞浸润能力,使肺转移结节数降低80%左右。结果提示:Ⅲ-11和ED-A结构顺序对Cell Ⅰ-Hep Ⅱ 双结构域多肽结合细胞的能力有一定的影响,但删除Ⅲ-11和ED-A不是重组多肽抑制肿瘤转移的决定因素,Cell I和Hep Ⅱ 这两个结构域单独连接在一起是其抑制肿瘤细胞转移的结构基础。 相似文献
34.
35.
曹厚德 《中国医疗器械信息》2007,13(11)
受印度尼西亚WIDYA MANDALA CATHOLIC UNIVERSITY校长Ami Soewandi教授的邀请,上海医疗器械高等专科学校副校长、上海理工大学医疗器械学院副院长张学龙教授,于2007年7月19日~23日参加在Surabaya希莱顿(Sheraton)大酒店召开的印度尼西亚"全国第6次技术设计与应用研讨会",并在会议开幕式上作关于"全方位产学研合作面向市场培养医疗器械类人才"的主题报告,反响热烈。 相似文献
36.
异丙酚在无抽搐电休克治疗麻醉中的应用 总被引:3,自引:0,他引:3
目的 :研究异丙酚在无抽搐电休克治疗 (MECT)麻醉中的应用效果及安全性。方法 :34例首次住院的精神分裂症患者随机分为异丙酚组和硫喷妥钠组 ,每组 17例 ,每例完成 1个疗程 6次MECT治疗 ,每组完成 10 2人次治疗 (n =10 2 )。每次治疗时 ,异丙酚组给予异丙酚静脉麻醉 ,硫喷妥钠组给予硫喷妥钠静脉麻醉 ,全麻诱导后皆静注琥珀酰胆碱 ,待肌肉松弛后行MECT治疗。全程监测患者心电图、血氧饱和度、血压、心率、脉搏 ,并观察记录自主呼吸恢复时间。苏醒时间和不良反应 ,进行前瞻性研究。结果 :与硫喷妥钠组相比 ,异丙酚组自主呼吸恢复快 ,苏醒快 ,无咳嗽 ,呃逆 ,呕吐等不良反应 ,两组差异显著。而异丙酚组注射点疼痛发生率显著高于硫喷妥钠组。结论 :在MECT中应用异丙酚静脉麻醉是一种更安全、有效的方法。 相似文献
37.
BERND-DIETER GONSKA KEJIANG CAO ANSELM SCHAUMANN AXEL DORSZEWSKI FRIEDERIKE von zur MÜHLEN HEINRICH KREUZER 《Pacing and clinical electrophysiology : PACE》1994,17(3):542-549
The management of patients after catheter ablation of ventricular tachycardia is not well defined. In this article we summarize recently published results and report our own experience. Factors influencing the clinical outcome of these patients and methods to identify patients with an increased risk of recurrence of ventricular tachycardia are discussed. Furthermore, a review is given on current concomitant therapeutic tools including antiarrhythmic drugs and the implantation of an automatic cardioverter defibrillator. 相似文献
38.
39.
40.
Piglets infected in utero with porcine reproductive and respiratory syndrome virus (PRRSV) are born severely immunocompromised. In this article we more closely examine the effects of in utero PRRSV infection on circulating and thymic T cell populations. Numbers of CD4+, CD8+, and dual-positive lymphocytes were quantitated in circulation and in the thymus during the 2 weeks following birth. At birth we found that the number of circulating lymphocytes was suppressed by 60%. Lymphocyte numbers were also suppressed by 42% at day 7, but by day 14 the number of lymphocytes had rebounded and was actually 47% greater than controls. At birth and day 7, a drop in the number of CD4+ cells could partially explain the suppression we observed, while the rebound in total lymphocyte numbers seen at day 14 was due to a nearly fourfold increase in the number of circulating CD8+ cells. As a result, the normal CD4+:CD8+ ratio of between 1.4 and 2.2 for neonatal pigs was reduced to 0.1-0.5. The thymuses of infected piglets were found to be 50% smaller than those of control pigs and were characterized by cortical involution and severe cortical depletion of thymocytes. Analysis of the population of thymocytes revealed that double-positive thymocytes were suppressed to a greater degree than either single positive subpopulation. In addition, we show that the number of thymocytes undergoing apoptosis was increased twofold in piglets infected with PRRSV. Taken together, these results help explain the dramatic immunosuppression observed in neonatal animals infected in utero with PRRSV. 相似文献