全文获取类型
收费全文 | 6682篇 |
免费 | 438篇 |
国内免费 | 38篇 |
专业分类
耳鼻咽喉 | 34篇 |
儿科学 | 131篇 |
妇产科学 | 189篇 |
基础医学 | 990篇 |
口腔科学 | 226篇 |
临床医学 | 528篇 |
内科学 | 1681篇 |
皮肤病学 | 181篇 |
神经病学 | 557篇 |
特种医学 | 226篇 |
外科学 | 959篇 |
综合类 | 52篇 |
预防医学 | 313篇 |
眼科学 | 99篇 |
药学 | 405篇 |
中国医学 | 16篇 |
肿瘤学 | 571篇 |
出版年
2023年 | 42篇 |
2022年 | 69篇 |
2021年 | 143篇 |
2020年 | 82篇 |
2019年 | 128篇 |
2018年 | 132篇 |
2017年 | 116篇 |
2016年 | 149篇 |
2015年 | 142篇 |
2014年 | 171篇 |
2013年 | 215篇 |
2012年 | 368篇 |
2011年 | 363篇 |
2010年 | 199篇 |
2009年 | 189篇 |
2008年 | 340篇 |
2007年 | 342篇 |
2006年 | 342篇 |
2005年 | 369篇 |
2004年 | 335篇 |
2003年 | 282篇 |
2002年 | 294篇 |
2001年 | 178篇 |
2000年 | 186篇 |
1999年 | 155篇 |
1998年 | 70篇 |
1997年 | 44篇 |
1996年 | 52篇 |
1995年 | 29篇 |
1994年 | 43篇 |
1993年 | 39篇 |
1992年 | 126篇 |
1991年 | 134篇 |
1990年 | 98篇 |
1989年 | 141篇 |
1988年 | 107篇 |
1987年 | 117篇 |
1986年 | 105篇 |
1985年 | 100篇 |
1984年 | 54篇 |
1983年 | 62篇 |
1981年 | 26篇 |
1979年 | 58篇 |
1978年 | 40篇 |
1977年 | 39篇 |
1972年 | 26篇 |
1969年 | 37篇 |
1968年 | 46篇 |
1967年 | 23篇 |
1966年 | 35篇 |
排序方式: 共有7158条查询结果,搜索用时 15 毫秒
1.
2.
3.
4.
Spinal antinociceptive effects of adenosine compounds in mice 总被引:1,自引:0,他引:1
The effects of injecting ATP, ADP, AMP, adenosine and adenine intrathecally on the pain response induced by the injection of substance P (10 ng/mouse) intrathecally were studied. All the compounds except adenine inhibited the pain response in a dose-related manner. The ED50 values of ATP, ADP, AMP and adenosine were 2.10, 0.93, 0.88 and 0.48 micrograms/mouse, respectively. Pretreatment with theophylline at a dose of 100 mg/kg p.o. markedly diminished all the antinociceptive effects. The effect of adenosine was not affected by s.c. injection of naloxone. These results suggest the existence of adenosine receptors which modulate spinal nociceptive sensory processing, independently of the endogenous opiate system. 相似文献
5.
M H Pietraszek S Takahashi Y Takada K Ohara H Inatomi N Kondo K Ohara A Takada 《Thrombosis research》1991,64(2):243-252
Diurnal changes of serotonin-related factors in whole blood and fibrinolytic activity were determined in depressed patients and healthy controls. Whole blood serotonin concentration of depressed patients showed marked changes throughout daytime, with maximum values in the evening and lowest values in the morning, whereas its metabolite 5-HIAA followed a contrary pattern. The circadian rhythm of 5-HT and 5-HIAA in the control group was quite different from depressed patients. Plasma levels of tPA decreased from 12:30 to 16:30. Concentrations of free plasminogen activator inhibitor (PAI-1) and complex of tPA-PAI-1 decreased from 8:30 to 16:30. Plasma levels of total PAI-1 decreased from 8:30 to 16:30. Plasma levels of the fibrinolytic parameters may be lower in depressive patients than in normal controls. These results support the changes in the circadian rhythm of serotonin and its related substances in the blood of depressive patients. 相似文献
6.
We investigated the effects of imaging and display conditions on the detectability of low-contrast objects in digital subtraction angiographic (DSA) images. The test images were produced by superimposition of low-contrast objects on a uniform noisy background obtained with a DSA system. We employed 18-alternative forced-choice (18-AFC) experiments and predictions based on statistical decision theory to study the dependence of the threshold contrasts of the test objects on the object size, incident x-ray exposure, display window width, and display medium. The results indicated that the threshold contrast decreased with increasing object size, and that the detectability of an object of a given size increased with increasing incident x-ray exposure and decreasing width of the display window. We found that the signal-to-noise ratio (SNR) obtained from the perceived statistical decision theory model, which includes the observer's internal noise, can accurately predict the detectability of low-contrast objects in DSA images. The threshold SNR corresponding to 50% correct detection in the 18-AFC experiments had a constant value of 3.8, in agreement with results reported previously for screen-film systems. The theoretical model will be useful for prediction of the performance of a DSA system based on its physical characteristics, and for evaluation of the tradeoff between patient exposure and diagnostic accuracy for a given DSA unit. 相似文献
7.
We report an 80-year-old Japanese male with four primary malignant tumors: malignant melanoma, prostatic cancer, malignant lymphoma, and renal cell carcinoma, which occurred in that respective order. The combination of malignant melanoma and malignant lymphoma is rare. The patient was treated with BCG after an operation for malignant melanoma. He was also treated with cobalt 60 irradiation after an operation for prostatic cancer. We also discuss other reports of multiple malignant tumors and suggest some possible causes of this patient's primary malignant tumors. 相似文献
8.
Tetsushi Tsujimoto Kazushi Daimon Kazuhide Izumi Maki Sawai Tatsuya Iwashige 《Seishin shinkeigaku zasshi》2007,109(4):313-320
Fifty two outpatients, who showed signs of school-refusal-withdrawal at the Shiga Prefectural Psychiatric Institution have been analyzed according to their age, gender, ICD-10 diagnosis, medical evolution, and total number of consultations. A total of 61.5% of the population were male, and they showed a higher average and a wider range of age than female patients. According to the ICD-10 diagnosis, 67.3% were in the group of F40-48 neurotic, stress-related and somatoform disorders, and 11.5% were in the group of F30-39 mood [affective] disorders. Twenty five % of the patients were assumed to have show medical improvement, and 42.3% of the patients continued to have further consultations. This article discusses the possible role of psychiatric medical institutions in supporting cases of school-refusal and social-withdrawal. 相似文献
9.
10.