全文获取类型
收费全文 | 974篇 |
免费 | 28篇 |
国内免费 | 75篇 |
专业分类
耳鼻咽喉 | 1篇 |
儿科学 | 46篇 |
妇产科学 | 19篇 |
基础医学 | 71篇 |
口腔科学 | 20篇 |
临床医学 | 130篇 |
内科学 | 237篇 |
皮肤病学 | 34篇 |
神经病学 | 35篇 |
特种医学 | 258篇 |
外科学 | 44篇 |
综合类 | 28篇 |
预防医学 | 45篇 |
眼科学 | 22篇 |
药学 | 44篇 |
中国医学 | 3篇 |
肿瘤学 | 40篇 |
出版年
2023年 | 5篇 |
2020年 | 4篇 |
2019年 | 8篇 |
2018年 | 7篇 |
2017年 | 5篇 |
2016年 | 11篇 |
2015年 | 13篇 |
2014年 | 15篇 |
2013年 | 14篇 |
2012年 | 13篇 |
2011年 | 16篇 |
2010年 | 31篇 |
2009年 | 49篇 |
2008年 | 17篇 |
2007年 | 47篇 |
2006年 | 24篇 |
2005年 | 21篇 |
2004年 | 10篇 |
2003年 | 13篇 |
2002年 | 12篇 |
2001年 | 19篇 |
2000年 | 20篇 |
1999年 | 10篇 |
1998年 | 82篇 |
1997年 | 70篇 |
1996年 | 59篇 |
1995年 | 51篇 |
1994年 | 43篇 |
1993年 | 44篇 |
1992年 | 22篇 |
1991年 | 15篇 |
1990年 | 25篇 |
1989年 | 35篇 |
1988年 | 34篇 |
1987年 | 26篇 |
1986年 | 24篇 |
1985年 | 25篇 |
1984年 | 18篇 |
1983年 | 11篇 |
1982年 | 17篇 |
1981年 | 9篇 |
1980年 | 13篇 |
1979年 | 5篇 |
1978年 | 6篇 |
1977年 | 17篇 |
1976年 | 13篇 |
1975年 | 14篇 |
1972年 | 2篇 |
1958年 | 2篇 |
1900年 | 2篇 |
排序方式: 共有1077条查询结果,搜索用时 15 毫秒
31.
Activated protein C decreases plasminogen activator-inhibitor activity in endothelial cell-conditioned medium 总被引:12,自引:0,他引:12
van Hinsbergh VW; Bertina RM; van Wijngaarden A; van Tilburg NH; Emeis JJ; Haverkate F 《Blood》1985,65(2):444-451
Confluent cultures of endothelial cells from human umbilical cord were used to study the effect of activated human protein C (APC) on the production of plasminogen activators, plasminogen activator-inhibitor, and factor VIII-related antigen. Addition of APC to the cells in a serum-free medium did not affect the production of tissue-type plasminogen activator (t-PA) or factor VIII-related antigen; under all measured conditions, no urokinase activity was found. However, less plasminogen activator-inhibitor activity accumulated in the conditioned medium in the presence of APC. This decrease was dose dependent and could be prevented by specific anti-protein C antibodies. No decrease was observed with the zymogen protein C or with diisopropylfluorophosphate-inactivated APC. APC also decreased the t-PA inhibitor activity in endothelial cell-conditioned medium in the absence of cells, which suggests that the effect of APC is at least partly due to a direct effect of APC on the plasminogen activator- inhibitor. High concentrations of thrombin-but not of factor Xa or IXa-- had a similar effect on the t-PA inhibitor activity. The effect of APC on the plasminogen activator-inhibitor provides a new mechanism by which APC may enhance fibrinolysis. The data suggest that activation of the coagulation system may lead to a secondary increase of the fibrinolytic activity by changing the balance between plasminogen activator(s) and its (their) fast-acting inhibitor. 相似文献
32.
33.
34.
35.
JJ Curiel-Valdés J Briones-Pimentel C Bandala 《International journal of clinical and experimental pathology》2014,7(9):5895-5901
Sensitivity of cervical cytology is suboptimal, especially in developing countries such as Mexico, despite available guidelines aimed at improving this. When obtaining cervical samples, whether the samples are taken from the transformation zone and whether abnormal cells are missing must be considered. Cervical secretions (CS) are always present in variable proportions, and when cleaning the cervix, better samples may be obtained. In this study, we analyzed samples obtained with or without cleaning the cervix, and compared their contents in order to determine the sensitivity and specificity of these two methods. Methods: Of 500 patients who underwent cytology and colposcopy, 271 (54.2%) required a second opinion due to a diagnosis of cervical intraepithelial neoplasia (CIN). CS was removed and compared with the clean, second sample (SS) using in both liquid-based cytology. The quality of samples according to the Bethesda System, the presence of CIN, and inflammatory reactions were recorded. The sensitivity and specificity were calculated using biopsy as the gold standard. Results: The SS resulted in a higher proportion of adequate samples being obtained (97.6% vs. 44.8%), and in increased sensitivity (88.2% vs. 58.8%). CIN was detected in the SS 26% more often than in the CS (34 vs. 27 samples), whereas inflammatory reactions were noted more often in the CS (91.4% vs. 74%). Conclusion: Cervical sampling including CS results in lower sensitivity and CIN detection rates, and in more inflammatory reactions. By excluding CS from cervical samples, the sensitivity could be improved and the false negative rate could be reduced. 相似文献
36.
37.
The incidence of lymphocysts was compared in two groups of patients treated by simple or radical hysterectomy including pelvic lymphadenectomy for carcinoma of the cervix and endometrium. Promoting factors for the formation of lymphocysts and the relation with thrombosis and prophylaxis are discussed. 相似文献
38.
39.
40.