全文获取类型
收费全文 | 23232篇 |
免费 | 1739篇 |
国内免费 | 394篇 |
专业分类
耳鼻咽喉 | 186篇 |
儿科学 | 534篇 |
妇产科学 | 430篇 |
基础医学 | 1792篇 |
口腔科学 | 104篇 |
临床医学 | 3098篇 |
内科学 | 5186篇 |
皮肤病学 | 80篇 |
神经病学 | 1340篇 |
特种医学 | 630篇 |
外科学 | 2475篇 |
综合类 | 2557篇 |
现状与发展 | 1篇 |
预防医学 | 3270篇 |
眼科学 | 60篇 |
药学 | 2882篇 |
11篇 | |
中国医学 | 336篇 |
肿瘤学 | 393篇 |
出版年
2024年 | 45篇 |
2023年 | 396篇 |
2022年 | 644篇 |
2021年 | 982篇 |
2020年 | 924篇 |
2019年 | 807篇 |
2018年 | 901篇 |
2017年 | 769篇 |
2016年 | 777篇 |
2015年 | 770篇 |
2014年 | 1510篇 |
2013年 | 1763篇 |
2012年 | 1325篇 |
2011年 | 1401篇 |
2010年 | 1098篇 |
2009年 | 1010篇 |
2008年 | 1076篇 |
2007年 | 1036篇 |
2006年 | 916篇 |
2005年 | 833篇 |
2004年 | 677篇 |
2003年 | 629篇 |
2002年 | 473篇 |
2001年 | 439篇 |
2000年 | 421篇 |
1999年 | 342篇 |
1998年 | 371篇 |
1997年 | 348篇 |
1996年 | 302篇 |
1995年 | 367篇 |
1994年 | 243篇 |
1993年 | 192篇 |
1992年 | 207篇 |
1991年 | 175篇 |
1990年 | 175篇 |
1989年 | 132篇 |
1988年 | 134篇 |
1987年 | 105篇 |
1986年 | 116篇 |
1985年 | 126篇 |
1984年 | 94篇 |
1983年 | 60篇 |
1982年 | 51篇 |
1981年 | 41篇 |
1980年 | 39篇 |
1979年 | 29篇 |
1978年 | 30篇 |
1977年 | 20篇 |
1975年 | 13篇 |
1973年 | 12篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
101.
超声心动图诊断原发性心脏肿瘤 总被引:1,自引:1,他引:0
目的:探讨原发性心脏肿瘤超声心动图(ECG)特征。方法:利用ECG检查42例心脏肿瘤。其中粘液瘤38例,恶性肉瘤2例,均经手术病理证实。横纹肌瘤2例,经随访证实。结果:ECG对38例粘液瘤,2例横纹肌瘤全部做出正确诊断。2例恶性肿瘤提示相应部位占位病变。粘液瘤多发生在左房,有明确的瘤蒂,肿瘤回声稀疏,活动度大。恶性肿瘤回声较强、无蒂,活动度小。横纹肌瘤多发生在室壁心肌内,呈结节状,与正常心肌间有明确的界限。结论:ECG对原发心脏肿瘤的诊断具有重要意义,可初步区分良、恶性肿瘤。 相似文献
102.
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
103.
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
104.
神经网络分析方法用于心脏病诊断的研究 总被引:2,自引:1,他引:1
神经网络可以很好的拟合任意的非线性函数。我们从 QRS波群的高频三维频谱中提取出一些定量的特征参数 ,用神经网络的方法对这些参数进行有监督的学习训练 ,最终能在由这些特征参数张成的 m维空间中构建出一个 m维的曲面来区分病人和健康人的 QRS波群高频三维频谱 ,从而使得训练后的网络能基于 QRS波群的高频三维频谱自行诊断出病人和健康人 相似文献
105.
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
106.
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
107.
I. M. E. Wentholt A. Maran N. Masurel R. J. Heine J. B. L. Hoekstra J. H. DeVries 《Diabetic medicine》2007,24(5):527-532
Aims We quantified the occurrence and duration of nocturnal hypoglycaemia in individuals with Type 1 diabetes treated with continuous subcutaneous insulin infusion (CSII) or multiple‐injection therapy (MIT) using a continuous subcutaneous glucose sensor. Methods A microdialysis sensor was worn at home by 24 patients on CSII (mean HbA1c 7.8 ± 0.9%) and 33 patients on MIT (HbA1c 8.7 ± 1.3%) for 48 h. Occurrence and duration of nocturnal hypoglycaemia were assessed and using multivariate regression analysis, the association between HbA1c, diabetes duration, treatment type (CSII vs. MIT), fasting and bedtime blood glucose values, total daily insulin dose and mean nocturnal glucose concentrations, and hypoglycaemia occurrence and duration was investigated. Results Nocturnal hypoglycaemia ≤ 3.9 mmol/l occurred in 33.3% of both the CSII‐ (8/24) and MIT‐treated patients (11/33). Mean (± sd ; median, interquartile range) duration of hypoglycaemia ≤ 3.9 mmol/l was 78 (± 76; 57, 23–120) min per night for the CSII‐ and 98 (± 80; 81, 32–158) min per night for the MIT‐treated group. Multivariate regression analysis showed that bedtime glucose value had the strongest association with the occurrence (P = 0.026) and duration (P = 0.032) of nocturnal hypoglycaemia. Conclusions Microdialysis continuous glucose monitoring has enabled more precise quantification of nocturnal hypoglycaemia occurrence and duration in Type 1 diabetic patients. Occurrence and duration of nocturnal hypoglycaemia were mainly associated with bedtime glucose value. 相似文献
108.
P A Zartner R P Handke A M Brecher M B E Schneider 《Europace : European pacing, arrhythmias, and cardiac electrophysiology》2007,9(3):192-193
A 4-year-old girl with post-surgical complete atrioventricular block received an epicardial dual chamber pacemaker system. During further growth intermittent exit block occurred, first misinterpreted as neurological seizures. The epicardial lead was replaced using a transvenous approach, and a pacemaker with an integrated home monitoring facility was implanted. After her discharge, a rise in the pacing threshold automatically initiated an event message. On the basis of this information, the patient was called in and imminent dislodgement of the ventricular lead was diagnosed by x-ray. The lead was repositioned and was found stable over 1-year follow-up. 相似文献
109.
Urban Sester Barbara C. Gärtner Heinrike Wilkens Bernhard Schwaab Rolf Wössner Ingrid Kindermann Matthias Girndt reas Meyerhans Nikolaus Mueller-Lantzsch Hans-Joachim Schäfers Gerhard W. Sybrecht Hans Köhler Martina Sester 《American journal of transplantation》2005,5(6):1483-1489
Patients after kidney, heart and lung transplantation differ in their immunosuppressive drug regimens and in susceptibility to infectious complications with cytomegalovirus (CMV). In this study, CMV-specific T-cell responses were characterized in long-term transplant recipients and associated with the frequency of infectious complications. CMV-reactive CD4 T cells from 50 healthy controls, 68 renal, 14 heart and 24 lung transplant recipients were flow cytometrically quantified by the induction of cytokines after specific stimulation. Moreover, the immunosuppressive effect of calcineurin inhibitors on specific T-cell reactivity was quantified in vitro and compared with responses in vivo. Median CMV-specific T-cell frequencies in long-term renal (1.48%; range 0.06-17.26%) and heart transplant recipients (0.90%; 0.13-12.49%) did not differ from controls (1.82%; 0.26-21.00%). In contrast, CMV-specific T-cell levels were significantly lower in lung transplant recipients (0.50%; <0.05-4.98%) and showed a significant correlation with the frequency of infectious episodes (r =-0.57, p = 0.005). The differences within the groups were associated with increasing dosages of immunosuppressive drugs, as exemplified for calcineurin inhibitors that dose dependently reduced specific T-cell reactivity in vitro. In conclusion, monitoring CMV-specific CD4 T cells may serve as a measure for long-term disease susceptibility and may contribute to an improved management of CMV complications after lung transplantation. 相似文献
110.
肛门括约肌肌电图监测下双侧L2~S2选择性脊神经后根切断术治疗痉挛性脑瘫 总被引:2,自引:1,他引:1
目的为提高手术安全性,在L2~S2选择性脊神经后根切断(SPR)手术时,对肛门括约肌进行肌电图(EMG)监测,并评价其作用。方法在SPR手术监测中,当对S2后根小束进行电刺激时,采用针状电极记录双侧肛门括约肌的反应情况,有明显反应的后根小束予以保留。手术后随访患者踝痉挛改善情况和括约肌功能变化情况。结果所有患者手术后踝痉挛均有明显改善,无大小便功能障碍发生。结论SPR手术包括S2后根时,术中括约肌EMG监测对保证疗效,保护括约肌功能,提高手术安全,具有重要意义。 相似文献