全文获取类型
收费全文 | 12445篇 |
免费 | 990篇 |
国内免费 | 71篇 |
专业分类
耳鼻咽喉 | 73篇 |
儿科学 | 296篇 |
妇产科学 | 202篇 |
基础医学 | 1551篇 |
口腔科学 | 226篇 |
临床医学 | 1631篇 |
内科学 | 2399篇 |
皮肤病学 | 178篇 |
神经病学 | 1254篇 |
特种医学 | 578篇 |
外国民族医学 | 1篇 |
外科学 | 2003篇 |
综合类 | 196篇 |
现状与发展 | 1篇 |
一般理论 | 9篇 |
预防医学 | 1007篇 |
眼科学 | 223篇 |
药学 | 919篇 |
中国医学 | 48篇 |
肿瘤学 | 711篇 |
出版年
2023年 | 53篇 |
2021年 | 224篇 |
2020年 | 133篇 |
2019年 | 204篇 |
2018年 | 273篇 |
2017年 | 194篇 |
2016年 | 205篇 |
2015年 | 220篇 |
2014年 | 383篇 |
2013年 | 474篇 |
2012年 | 746篇 |
2011年 | 899篇 |
2010年 | 424篇 |
2009年 | 427篇 |
2008年 | 667篇 |
2007年 | 802篇 |
2006年 | 647篇 |
2005年 | 734篇 |
2004年 | 620篇 |
2003年 | 602篇 |
2002年 | 596篇 |
2001年 | 234篇 |
2000年 | 264篇 |
1999年 | 253篇 |
1998年 | 172篇 |
1997年 | 149篇 |
1996年 | 151篇 |
1995年 | 120篇 |
1994年 | 110篇 |
1993年 | 111篇 |
1992年 | 159篇 |
1991年 | 134篇 |
1990年 | 140篇 |
1989年 | 149篇 |
1988年 | 137篇 |
1987年 | 145篇 |
1986年 | 121篇 |
1985年 | 163篇 |
1984年 | 130篇 |
1983年 | 93篇 |
1982年 | 81篇 |
1981年 | 87篇 |
1980年 | 72篇 |
1979年 | 82篇 |
1978年 | 65篇 |
1977年 | 68篇 |
1976年 | 59篇 |
1975年 | 38篇 |
1974年 | 46篇 |
1972年 | 46篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
31.
High-dose gadoteridol in MR imaging of intracranial neoplasms. 总被引:6,自引:0,他引:6
V M Runge J E Kirsch V J Burke A C Price K L Nelson G S Thomas B L Dean C Lee 《Journal of magnetic resonance imaging : JMRI》1992,2(1):9-18
Twelve patients with a high suspicion of brain metastases by previous clinical or radiologic examinations were studied in a phase III investigation with magnetic resonance (MR) imaging at 1.5 T after a bolus intravenous injection of 0.1 mmol/kg gadoteridol followed at 30 minutes by a second bolus injection of 0.2 mmol/kg gadoteridol. All lesions were best demonstrated (showed greatest enhancement) at the 0.3-mmol/kg (cumulative) dose, with image analysis confirming signal intensity enhancement in the majority of cases after the second gadoteridol injection. More lesions were detected with the 0.3-mmol/kg dose than with the 0.1-mmol/kg dose, and more lesions were detected with the 0.1-mmol/kg dose than on precontrast images. In this limited clinical trial, high-dose gadoteridol injection (0.3-mmol/kg cumulative dose) provided improved lesion detection on MR images specifically in intracranial metastatic disease. 相似文献
32.
33.
P M Phillips F M Dean J Reffin T P Briggs R A Miller C C Davey 《British journal of urology》1992,70(5):488-491
A study comparing the macular function of both eyes of 130 urological surgeons was carried out to investigate whether the increased light exposure to the endoscoping eye caused any deterioration of macular function. The non-endoscoping eye was used as a control. A sophisticated computer test of colour contrast sensitivity was used. The computer assesses the degree of brightness at which the subject is just able to detect a coloured grating, and for each eye this is expressed as a threshold for the red/green axis and the blue/yellow (tritan) axis. The subjects also completed a questionnaire about their working patterns and their general and ophthalmic history and had a brief examination of the fundus. The results do not suggest that urologists are suffering any significant macular damage as a result of their work with endoscopes. 相似文献
34.
35.
A 21-year-old man developed the adult respiratory distress syndrome (ARDS) within five hours of receiving antilymphocyte globulin. No other identifiable cause of ARDS was present. The mechanism for development of acute lung injury is unknown, but may be related either to direct lung cytotoxicity or to complement-mediated leukocyte and platelet destruction with secondary lung injury from inflammatory mediators. 相似文献
36.
Depressed antigen presentation function and membrane interleukin-1 activity of peritoneal macrophages after laparotomy 总被引:5,自引:0,他引:5
Although major tissue trauma produces profound depression of cell-mediated immunity, it is not known whether surgical trauma (i.e., midline laparotomy) has any adverse effect on the antigen presentation function and membrane interleukin-1 (IL-1) activity of peritoneal macrophages. To study this, C3H/HEJ (endotoxin-tolerant) mice were anesthetized. An approximately 1-inch midline abdominal incision was made, followed by abdominal closure. On days 1, 3, 5, and 7, peritoneal macrophages were harvested by means of peritoneal lavage, and antigen presentation capability was tested by incubating various numbers of peritoneal macrophages with 2 X 10(4) D10.G4.1 cells per well in the presence of conalbumin (400 micrograms/ml). The T helper cell clone (D.10.G4.1) proliferates on recognition of conalbumin in the context of Iak and also proliferates in the presence of membrane-bound IL-1 plus concanavalin A. To measure membrane IL-1 expression in peritoneal macrophages, Concanavalin A (10 micrograms/ml) was substituted for conalbumin. Cultures were incubated for 72 hours, pulsed with tritiated thymidine, and harvested. Peritoneal macrophages from laparotomized mice induced significantly less T helper cell proliferation on days 1 and 3 in the antigen presentation assay (37% and 30%, respectively; p less than 0.05) and in the membrane IL-1 assay (14% and 10%, respectively; p less than 0.05) as compared with the control. This difference was not detectable on day 5. More effective antigen presentation capability (167% of control; p less than 0.05) was seen on day 7. Thus laparotomy by itself produces marked depression of both antigen presentation function and membrane IL-1 activity of peritoneal macrophages, which may enhance susceptibility to intra-abdominal sepsis. 相似文献
37.
38.
Mechanisms of zinc (Zn) toxicity are incompletely understood and data regarding potential endocrine alterations in Zn toxicity are scarce. To examine mechanisms of Zn toxicity, day-old chicks were pair-fed diets containing 5280 ppm (Hz) or 73 ppm (CON) Zn. Impaired postnatal growth, independent of feed consumption, and multiple endocrinopathies were observed following short-term (1-2 weeks) exposure to the high Zn diet. Reduced levels of serum cholesterol, high-density lipoprotein cholesterol, and growth hormone were associated with HZ feeding. Depressed levels of circulating thyroid hormones and histological evidence that follicle area of thyroids from HZ birds was 63% less than CON indicated that impaired growth of HZ birds may be caused, in part, by reduced thyroidal function. 相似文献
39.
Weyers'' ulnar ray/oligodactyly syndrome and the association of midline malformations with ulnar ray defects. 下载免费PDF全文
We describe a two generation family with variable ulnar and radial ray reduction and midline craniofacial abnormalities. The features suggest a diagnosis of Weyers' ulnar ray/oligodactyly syndrome originally described in two isolated cases. Syndromes of ulnar ray reduction are briefly reviewed and the relationship between limb bud and midline development discussed. 相似文献
40.