全文获取类型
收费全文 | 206128篇 |
免费 | 18078篇 |
国内免费 | 11821篇 |
专业分类
耳鼻咽喉 | 2038篇 |
儿科学 | 2799篇 |
妇产科学 | 4053篇 |
基础医学 | 23465篇 |
口腔科学 | 4007篇 |
临床医学 | 26329篇 |
内科学 | 31671篇 |
皮肤病学 | 2565篇 |
神经病学 | 10628篇 |
特种医学 | 7150篇 |
外国民族医学 | 90篇 |
外科学 | 21324篇 |
综合类 | 29597篇 |
现状与发展 | 40篇 |
一般理论 | 40篇 |
预防医学 | 14286篇 |
眼科学 | 6192篇 |
药学 | 21489篇 |
180篇 | |
中国医学 | 10580篇 |
肿瘤学 | 17504篇 |
出版年
2024年 | 588篇 |
2023年 | 2838篇 |
2022年 | 6944篇 |
2021年 | 9239篇 |
2020年 | 6821篇 |
2019年 | 6401篇 |
2018年 | 6813篇 |
2017年 | 6048篇 |
2016年 | 5779篇 |
2015年 | 8778篇 |
2014年 | 11153篇 |
2013年 | 10834篇 |
2012年 | 15917篇 |
2011年 | 17096篇 |
2010年 | 11333篇 |
2009年 | 9090篇 |
2008年 | 11835篇 |
2007年 | 11689篇 |
2006年 | 11369篇 |
2005年 | 10585篇 |
2004年 | 7475篇 |
2003年 | 6813篇 |
2002年 | 5621篇 |
2001年 | 4801篇 |
2000年 | 4541篇 |
1999年 | 4624篇 |
1998年 | 2554篇 |
1997年 | 2442篇 |
1996年 | 1911篇 |
1995年 | 1815篇 |
1994年 | 1614篇 |
1993年 | 961篇 |
1992年 | 1463篇 |
1991年 | 1277篇 |
1990年 | 1126篇 |
1989年 | 971篇 |
1988年 | 885篇 |
1987年 | 737篇 |
1986年 | 602篇 |
1985年 | 494篇 |
1984年 | 313篇 |
1983年 | 252篇 |
1982年 | 136篇 |
1981年 | 143篇 |
1980年 | 95篇 |
1979年 | 202篇 |
1978年 | 130篇 |
1977年 | 95篇 |
1974年 | 121篇 |
1972年 | 97篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
211.
Chien-Chih Lin 《Surgical endoscopy》1990,4(4):224-226
Summary Although hyperhidrosis palmaris is a benign condition, it may cause considerable psychological, social, and occupational disturbances. There are many conservative measures used to treat hyperhidrosis, but surgical sympathectomy is the only permanent cure. Of the various surgical approaches to the upper thoracic sympathetic ganglia, one must select the approach that combines good functional results and a satisfactory cosmetic outcome with only minor complications. Twenty-one patients (10 men and 11 women) with hyperhidrosis palmaris underwent synchronous bilateral T2 sympathectomy between 1 October 1989 and 30 April 1990. These patients underwent a new method of thoracoscopic sympathectomy without preoperative pneumothorax. All were relieved of excessive sweating in their upper extremities immediately after the operation. In addition, the technique led to significant savings in operation and hospitalization time. We recommend thoracoscopic sympathectomy as the best approach for sympathectomy in cases of hyperhidrosis palmaris. 相似文献
213.
Chien-Huang Lin Feng-Nien Ko Hisahi Ishii Tsutomu Ishikawa Ih-Sheng Chen Che-Ming Teng H.-P. Kuo 《Naunyn-Schmiedeberg's archives of pharmacology》1997,355(2):210-216
We investigated the effects of a novel platelet-activating factor (PAF) receptor antagonist, CIS-19 [cis-2-(3, 4-dimethoxyphenyl)-6-isopropoxy-7-methoxy-1-(N-methylformamido)-1,
2, 3, 4-tetrahydronaphthalene], on PAF-, histamine-, substance P- and antigen-induced bronchoconstriction and microvascular
leakage, as well as PAF- and antigen-induced bronchial hyperreactivity to methacholine in urethane-anesthetized guinea-pigs.
Administration of CIS-19 (0.5–5 mg/kg, i.v.) inhibited the increase in lung resistance induced by PAF (30 ng/kg, i.v.) in
a dose-dependent manner, but failed to inhibit the increase induced by histamine (30 μg/kg, i.v.) or substance P (6.5 μg/kg,
i.v.). CIS-19 (5 mg/kg, i.v.) did not inhibit the increase in lung resistance induced by ovalbumin (2 mg/kg, i.v.) in actively
sensitized guinea-pigs. PAF (30 ng/kg, i.v.)-induced microvascular leakage, measured by the extravasation of Evans blue dye,
was dose-dependently inhibited by CIS-19 (0.5–5 mg/kg, i.v.) in the trachea, main bronchi and intrapulmonary airways, but
it did not affect histamine (30 μg/kg, i.v.)- or substance P (6.5 μg/kg, i.v.)-induced microvascular leakage at all airway
levels. CIS-19 (2.5 and 5 mg/kg) did not affect ovalbumin (2 mg/kg, i.v.)-induced microvascular leakage in all airway levels
in actively sensitized guinea-pigs. CIS-19 (2.5 and 5 mg/kg, i.v.) significantly inhibited PAF-induced enhancement of the
bronchial response to methacholine, but had no effect on ovalbumin (0.05 mg/kg, i.v.)-induced bronchial hyperreactivity in
actively sensitized guinea-pigs. It is concluded that CIS-19 is a potent PAF receptor antagonist which inhibits PAF- but not
antigen-induced bronchoconstriction, microvascular leakage and bronchial hyperreactivity. These results suggest that PAF plays
little or no role in early airway responses following antigen challenge.
Received: 29 April 1996 / Accepted: 10 October 1996 相似文献
214.
A tissue equivalent phantom was used in the study and absored x-ray doses.It measuring for some important organs of head and neck by four routive sialography methods (panoramic conventional x-ray radioagraphy,tomography,fluoroscope,CT) and also the X-ray absorbed doses of thyroid and len when lead containing loop and spectacles of head containing glass were used for prevention.All the data were processed statistically and a compartive study of absorbed x-ray doses of four sialography methods:Doses of submandibular gland were higher in CT,tomography and fluoroscope among them,CT was the highest indicating that it was superior to other methods for accurately locating that it was superior to other methods for accurately locating the within-gland tumor.Fluoroscope will be use more frequently in clinic,because it can observe the living gland panoramic and normal radiography can be used routinely because they had the minimum doses in measured organs.2.The absorbed x-ray doses of len and thyroid decreased by 93%-% when prevention was taken in CT or fluoroscope,65%-85% doses was decreased in normal radiography or panoramic with prevention. 相似文献
215.
为了探索单疱病毒性角膜炎的发病机制和快速诊断HSK。方法应用多聚酶链反应对感染的HSK的20只纯新西兰白兔和60例HSK患者的角膜进行了单疱病毒-1-DNA检测。结果急性感染期的5只兔角膜和12只人角膜均阳性;用稳定期45d的兔角供体行部分穿透性角膜移植术,术后50d10只兔角膜中7只阳性,稳定期6个月-6年的18只人角膜片,12只阳性;30例临床可疑HSK角膜刮取物,26例阳性;5只未感染HSK 相似文献
216.
Twenty-eight breasts of 15 patients with macromastia underwent reduction mammaplasty from 1982 to 1989. We followed up these patients postoperatively for 6 months to 7 years. The follow-up time for 8 patients was over 1 year, and 4 patients over 5 years. And 3 patients labored and lactated. These 15 patients were satisfied with this operative results. The operative technology was based on Pitange's method. This method improved the site of the nipple, transposition of nipple-areola complex, and design of dermal pedicle, so that it had better effects in the breast shape, breast fixation and incision scar concealed. We suggest that the purpose of macromastia treated in reducing volume, improving breast shape, preserving lactating function. This paper also discusses the methods for nipple site, nipple-areola complex transposition, breast resection and mastopexy. 相似文献
217.
218.
J.-P. Zhang J.-M. Xia Grace Y. Sun 《Alcoholism, clinical and experimental research》1997,21(4):716-720
Many neurotransmitters and hormones in the nervous system transmit signals through receptors coupled to the poly-phosphoinositide (PI) signaling pathway. In this study, an in vivo protocol with (3H]inositol was used to examine the effect of chronic ethanol administration on inositol metabolism and poly-PI turnover in the cerebral cortex, hippocampus, and cerebellum of mouse brain. C57BL/6 mice were given a nutritionally complete liquid diet containing either ethanol (5%, w/v) or isocaloric sucrose for 2 months. Mice were injected intracerebrally with rH]inositol; after 16 or 24 hr, they were injected intraperitoneally with lithium (8 mEq/kg body weight) to inhibit the inositol monophosphatase (IP1) activity. All mice were decapitated 4 hr after lithium injection. Labeled inositol phospholipids accounted for 16 to 23% of total labeled inositol in different regions of control mouse brain, and the percentages in the hippocampus were consistently higher than the cerebral cortex and cerebellum. In control mice, the percentages of labeled IP, after a 4-hr lithium treatment were 11.5%, 9.9%, and 3.7% for cerebral cortex, hippocampus, and cerebellum, respectively. Chronic ethanol feeding resulted in a significant (p < 0.05) decrease in the percent of labeled IP1 and inositol phospholipids, and this effect was observed in the cerebral cortex and, to a lesser extent, hippocampus but not cerebellum. When ratios of labeled IP1 were expressed against labeled inositol phospholipids as an index of the poly-PI turnover activity, significant decreases in IP/lipid ratios were observed in the cerebral cortex, but not the hippocampus or cerebellum. Although mice killed 24 + 4 hr after the last ethanol feeding would have experienced an 8-hr period of ethanol withdrawal, compared with the 16 + 4-hr group, no differences in IP/lipid ratios were observed between the two time groups. These results illustrate regional differences in the effect of chronic ethanol on inositol metabolism in the brain, but no difference in poly-PI turnover in brain due to ethanol withdrawal. 相似文献
219.
选择性髂内动脉结扎与栓塞对盆腔血供的影响 总被引:5,自引:0,他引:5
目的:旨在探讨选择性髂内动脉结扎与栓塞两种方法对盆腔血供的影响。方法:将两组犬在膀胱上动脉分支以下之髂内动脉分别行结扎与栓塞,对比观察两组膀胱创面出血、盆腔动脉造影及盆腔脏器组织学变化,以确定其盆腔脏器的血供情况。结果:①结扎组膀胱创面出血明显大于栓塞组;②结扎组髂内动脉侧支循环建立时间明显早于且数目多于栓塞组;③两组盆腔脏器均未见缺血坏死。结论:栓塞组阻断髂内动脉侧支循环的数目多于结扎组,故对盆腔血供的影响大于结扎组。避免髂内动脉阻断范围过广可减少盆腔脏器缺血坏死的机会。 相似文献
220.
缺氧缺血性脑病新生鼠胃壁内一氧化氮的改变 总被引:12,自引:1,他引:11
目的探讨缺氧缺血性脑病新生鼠胃壁局部一氧化氮(NO)的改变及窒息对消化系统的影响。方法采用二氢硫辛酰胺脱氢酶NADPH组织化学方法,检测24只正常或缺氧新生鼠胃壁各层一氧化氮合成酶(NOS)的分布变化。结果急性缺氧组与正常对照组相比,NOS阳性产物无论在分布、染色深浅、纤维密度及NOS阳性胞体数目上,差异均无显著意义(P>0.05)。但在缺氧缺血性脑病组,其肌层的NOS阳性纤维无论是密度还是染色深浅,均明显强于正常对照组,NOS阳性胞体亦明显多于正常对照组,其差异有非常显著意义(P<0.01);而粘膜和粘膜下层的NOS分布与正常对照组相比,差异无显著意义(P>0.05)。结论窒息时胃动力降低及胃粘膜病变与一氧化氮在胃壁内的改变有关 相似文献