全文获取类型
收费全文 | 47441篇 |
免费 | 3215篇 |
国内免费 | 798篇 |
专业分类
耳鼻咽喉 | 302篇 |
儿科学 | 793篇 |
妇产科学 | 795篇 |
基础医学 | 2692篇 |
口腔科学 | 238篇 |
临床医学 | 4774篇 |
内科学 | 6555篇 |
皮肤病学 | 530篇 |
神经病学 | 2197篇 |
特种医学 | 873篇 |
外科学 | 3375篇 |
综合类 | 5454篇 |
现状与发展 | 1篇 |
预防医学 | 6526篇 |
眼科学 | 225篇 |
药学 | 12765篇 |
20篇 | |
中国医学 | 826篇 |
肿瘤学 | 2513篇 |
出版年
2024年 | 76篇 |
2023年 | 659篇 |
2022年 | 1388篇 |
2021年 | 1807篇 |
2020年 | 1564篇 |
2019年 | 1448篇 |
2018年 | 1445篇 |
2017年 | 1404篇 |
2016年 | 1483篇 |
2015年 | 1628篇 |
2014年 | 3392篇 |
2013年 | 4029篇 |
2012年 | 3246篇 |
2011年 | 3578篇 |
2010年 | 2622篇 |
2009年 | 2497篇 |
2008年 | 2464篇 |
2007年 | 2335篇 |
2006年 | 1998篇 |
2005年 | 1661篇 |
2004年 | 1353篇 |
2003年 | 1144篇 |
2002年 | 843篇 |
2001年 | 776篇 |
2000年 | 718篇 |
1999年 | 681篇 |
1998年 | 516篇 |
1997年 | 482篇 |
1996年 | 398篇 |
1995年 | 457篇 |
1994年 | 362篇 |
1993年 | 280篇 |
1992年 | 280篇 |
1991年 | 232篇 |
1990年 | 216篇 |
1989年 | 169篇 |
1988年 | 204篇 |
1987年 | 172篇 |
1986年 | 173篇 |
1985年 | 193篇 |
1984年 | 188篇 |
1983年 | 105篇 |
1982年 | 105篇 |
1981年 | 79篇 |
1980年 | 92篇 |
1979年 | 69篇 |
1978年 | 78篇 |
1977年 | 65篇 |
1976年 | 64篇 |
1975年 | 75篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
201.
A. Gautam S.A. Fischer A.F. Yango R.Y. Gohh P.E. Morrissey A.P. Monaco 《International immunopharmacology》2006,6(13-14):2023
Cell mediated immunity (CMI) was assessed by the ImmuKnow assay in 12 patients after kidney transplantation, who presented with viral infection. Treatment included lowering of immunosuppression in all cases and antiviral treatment if indicated. The assay was repeated during the follow up. The ImmuKnow assay at time of presentation of viral infections was 56.8 ± 58.2 (range 3–178; median 22) ATP ng/ml. With the clearance of viral infection and lowering of immunosuppression, the assay showed an increase in the level of CMI at 194.5 ± 118.9 (range 53–409; median 150) ATP ng/ml. There was viral clearance or stabilization in all cases and there was no incidence of allograft rejection. The ImmuKnow assay of CMI can be used to titrate initial immunosuppression reduction and its subsequent increase, in patients with viral infection after transplantation. 相似文献
202.
The effect of oral appliance therapy on blood pressure in patients with obstructive sleep apnea 总被引:1,自引:1,他引:0
Ryo Otsuka Fernanda Ribeiro de Almeida Alan A. Lowe Wolfgang Linden Frank Ryan 《Sleep & breathing》2006,10(1):29-36
The objective of the study was to investigate the effects of oral appliance (OA) therapy on ambulatory blood pressure in patients
with obstructive sleep apnea (OSA). Eleven OSA patients who received OA therapy were prospectively investigated. Ambulatory
blood pressure was measured for 20 h from 4:00 p.m. to 12:00 noon the next day using an ambulatory blood pressure monitor. The Respiratory Disturbance Index (RDI) was measured
in the pretreatment and posttitration periods. The OA was titrated to reach a therapeutic jaw position over 2 to 8 months,
and posttitration measurements were repeated. At posttitration, the RDI was significantly decreased from a mean (SD) of 24.7
(20.1) to 6.1 (4.5). Significant reductions in diastolic blood pressure (DBP) and mean arterial pressure (MAP) were found
for the 20-h periods, and systolic blood pressure (SBP), DBP, and MAP while asleep. The mean values were 79.5 (5.5) to 74.6
(6.0) for DBP and 95.9 (5.4) to 91.2 (5.9) for MAP, for over a 20-h period, and 118.4 (10.0) to 113.7 (9.1) for SBP, 71.6
(8.0) to 67.2 (7.9) for DBP, and 88.4 (8.0) to 83.9 (7.5) for MAP, while asleep. This study suggests that successful OSA treatment
with an OA may also be beneficial to lower blood pressure in OSA patients, as previously suggested for nasal continuous positive
airway pressure therapy.
This study was conducted in the Division of Orthodontics, The University of British Columbia, Canada 相似文献
203.
204.
Recent evidence suggests that the putative dopamine (DA) autoreceptor antagonists, (+)-AJ 76 and (+)-UH 232, share some neurochemical and behavioral effects with both psychostimulants and neuroleptics. The ability of (+)-AJ 76 and (+)-UH 232 to mimic or antagonize the stimulus effects of cocaine was investigated in rats trained to discriminate 5 mg/kg (N=8) or 10 mg/kg (N=8) of cocaine from saline in a two-lever, water-reinforced, drug discrimination task. In the cocaine (10 mg/kg) group, administration of (+)-AJ 76 (2.5–20 mg/kg) engendered only a partial substitution for cocaine (maximum 60% cocaine-lever responses). Given in combination with cocaine (10 mg/kg), (+)-AJ 76 (2.5–40 mg/kg) did not significantly attenuate the cocaine cue. A fixed dose of (+)-AJ 76 (2.5 or 10 mg/kg) plus various doses of cocaine (1.25–5 mg/kg) did not alter the cocaine dose-response curve. (+)-UH 232 (2–16 mg/kg) produced primarily saline-appropriate responding in rats trained to discriminate 5 mg/kg of cocaine and was unable to block the interoceptive cocaine state when given in combination with cocaine (5 mg/kg). (+)-UH 232 (2 or 8 mg/kg) also did not alter the cocaine dose-response curve. These results suggest that (+)-AJ 76 and (+)-UH 232 elicit only weak or no cocaine-like stimulus effects and, unlike neuroleptics, do not attenuate the cocaine cue. 相似文献
205.
南京口岸1987—1993年艾滋病监测报告 总被引:1,自引:1,他引:0
本文报道了南京卫生检疫局1987~1993连续7年对南京口岸重点人群进行艾滋病监测的情况.7年来南京局共监测各类标本43085份,在外籍留学生中检出HIV感染者2例,另外还检出4份进口人血丙种球旦白HIV抗体阳性.该局对检出的2侧HIV感染者及4份阳性进口人血丙种球旦白进行了游行病学调查和处理.并对艾滋病监测管理的有关问题进行了探讨. 相似文献
206.
Summary A ring-shaped electrode was developed and used in 20 patients to record evoked electromyographic responses directly from the extraocular muscles during skull base surgery. Intra-operative monitoring with this electrode helps the surgeon to localize the nerves that innervate the extraocular muscles precisely and to refrain from disturbing important neural structures during operations. Such monitoring also provides some insight into the pathophysiology of the dysfunction of these nerves resulting from skull base lesions. 相似文献
207.
208.
Bayesian decision theoretic approaches (BDTAs) have been widely studied in the literature as tools for designing and conducting phase II clinical trials. However, full Bayesian approaches that consider multiple endpoints are lacking. Since the monitoring of toxicity is a major goal of phase II trials, we propose an adaptive group sequential design using a BDTA, which characterizes efficacy and toxicity as correlated bivariate binary endpoints. We allow trade‐off between the two endpoints. Interim evaluations are conducted group sequentially, but the number of interim looks and the size of each group are chosen adaptively based on current observations. We utilize a loss function consisting of two components: the loss associated with accruing, treating, and monitoring patients, and the loss associated with making incorrect decisions. The performance of our Bayesian modeling, and the operating characteristics of decision rules under a wide range of loss function parameters are evaluated using seven scenarios in a simulation study. Our method is illustrated in the context of a single‐arm phase II trial of bevacizumab, gemcitabine, and oxaliplatin in patients with metastatic pancreatic adenocarcinoma. Copyright © 2009 John Wiley & Sons, Ltd. 相似文献
209.
Summary: The goal of this study was to develop a new model of ischemia-induced seizures in immature rats using injection of vasoconstrictor Endothelin-1 (ET-1) into the brain. ET-1 (10, 20, or 40 pmol) was infused into the left dorsal hippocampus of freely moving Wistar rats 12 (P12) and 25 (P25) days old. Animals were then video/EEG-monitored for 100 min and monitoring was repeated 22 h later. Parameters of electrographic seizures (frequency and mean duration) as well as pattern of their behavioral correlates were evaluated. The pattern of behavioral seizures was used to develop model-specific scoring system. Cresyl violet and Fluoro Jade-B-staining were used to evaluate brain damage. Extension of the lesion was correlated with seizure severity. After ET-1-injection, seizures occurred in 83–100% animals of all age-and-dose groups and persisted for 24 h except P12 rats with 10 pmol. There were no differences in average seizure duration (18–40 s) or seizure frequency (3–7 seizures/100 min) among individual dose-groups. Between the 1st and 2nd observation period, total seizure duration decreased in 71% of P12 and 47% of P25 rats. Electrographic seizure activity was most frequently accompanied by clonus, incidence of more severe convulsions (barrel rolling or generalized clonic seizures) increased with dose of ET-1. Morphologic examination did not reveal any dose-related difference in damage severity, hippocampal damage was however more extensive in P12 compared to P25 animals. Seizure severity correlated positively with severity of the damage in both age groups. Our study presents focal injection of ET-1 into the brain as a new and practical model of ischemia-induced seizures in immature rats. 相似文献
210.
老年患者尿路感染菌群分布及其耐药性分析 总被引:3,自引:0,他引:3
目的 :了解老年患者尿路感染致病菌的菌群分布及其对抗生素的耐药情况 ,为临床合理使用抗生素提供依据。方法 :收集湖北省 15所三级甲等医院 2 0 0 2年尿路感染老年患者清洁中段尿细菌培养分离的 5 34株致病菌 ,对其进行耐药性监测。药敏采用K B法 ,用WHONET 5软件进行数据分析。结果 :共收集致病菌 5 34株 ,其中革兰阴性菌 4 0 9株 (76 .6 % ) ,革兰阳性菌 12 5株(2 3.4 % )。革兰阴性菌中大肠埃希菌检出率最高 (2 6 4株 ,4 9.4 % ) ,其次为克雷白杆菌 (44株 ,8.2 % )。 16 .7%的大肠埃希菌和 2 2 .7%的克雷白杆菌产超广谱 β 内酰胺酶。亚胺培南、阿米卡星、头孢他啶对革兰阴性菌的抗菌活性最强 ,而革兰阴性菌对环丙沙星、庆大霉素、哌拉西林的耐药率均在 5 0 %以上。革兰阳性菌以肠球菌最多见 (6 4株 ,12 % ) ,其次为葡萄球菌属 (43株 ,8.1% )。革兰阳性菌对SMZco、红霉素等的耐药率均在 4 0 %以上 ,但对万古霉素均敏感。结论 :老年患者尿路感染以革兰阴性菌为优势菌株 ,且耐药性日益严重 ,对亚胺培南、阿米卡星、头孢他啶最为敏感。革兰阳性菌宜以万古霉素为首选。 相似文献