全文获取类型
收费全文 | 11735篇 |
免费 | 879篇 |
国内免费 | 94篇 |
专业分类
耳鼻咽喉 | 91篇 |
儿科学 | 341篇 |
妇产科学 | 273篇 |
基础医学 | 1330篇 |
口腔科学 | 176篇 |
临床医学 | 1117篇 |
内科学 | 2475篇 |
皮肤病学 | 158篇 |
神经病学 | 839篇 |
特种医学 | 424篇 |
外科学 | 1807篇 |
综合类 | 257篇 |
一般理论 | 7篇 |
预防医学 | 730篇 |
眼科学 | 981篇 |
药学 | 777篇 |
中国医学 | 71篇 |
肿瘤学 | 854篇 |
出版年
2023年 | 109篇 |
2022年 | 163篇 |
2021年 | 339篇 |
2020年 | 199篇 |
2019年 | 292篇 |
2018年 | 326篇 |
2017年 | 221篇 |
2016年 | 217篇 |
2015年 | 266篇 |
2014年 | 346篇 |
2013年 | 426篇 |
2012年 | 658篇 |
2011年 | 716篇 |
2010年 | 411篇 |
2009年 | 372篇 |
2008年 | 623篇 |
2007年 | 723篇 |
2006年 | 690篇 |
2005年 | 662篇 |
2004年 | 600篇 |
2003年 | 551篇 |
2002年 | 509篇 |
2001年 | 445篇 |
2000年 | 397篇 |
1999年 | 324篇 |
1998年 | 117篇 |
1997年 | 90篇 |
1996年 | 85篇 |
1995年 | 67篇 |
1994年 | 65篇 |
1993年 | 63篇 |
1992年 | 177篇 |
1991年 | 173篇 |
1990年 | 149篇 |
1989年 | 117篇 |
1988年 | 126篇 |
1987年 | 141篇 |
1986年 | 101篇 |
1985年 | 96篇 |
1984年 | 59篇 |
1983年 | 72篇 |
1982年 | 47篇 |
1981年 | 41篇 |
1980年 | 42篇 |
1979年 | 67篇 |
1978年 | 48篇 |
1977年 | 21篇 |
1976年 | 14篇 |
1973年 | 16篇 |
1972年 | 15篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
11.
A 45-year-old man with neurofibromatosis presented with recurrent seizures due to hypoglycaemia caused by an insulinoma. The attacks were abolished after the successful removal of the insulinoma. This probably represents another example of the association between neurofibromatosis and a tumour consisting of cells with amine-precursor-uptake and decarboxylation. 相似文献
12.
IgA nephropathy associated with sarcoidosis 总被引:1,自引:0,他引:1
13.
Sylvie Naar-King Kathryn Wright Jeffrey T Parsons Maureen Frey Thomas Templin Phebe Lam Debra Murphy 《AIDS education and prevention》2006,18(1):1-11
This study piloted a brief individual motivational intervention targeting multiple health risk behaviors in HIV-positive youth aged 16-25. Interviews about sexual behavior and substance use and viral load testing were obtained from 51 HIV-positive youth at baseline and post intervention. Youth were randomized to receive a four-session motivational enhancement intervention (N = 25) or to a wait-list control (N = 26). Of the eligible youth approached, 88% agreed to participate, and 80% percent of participants completed at least three of four sessions. The treatment group showed significantly greater reductions in unprotected sex acts and in viral load compared with controls. Although change scores for substance use were not significantly different between the two groups, paired t tests demonstrated that reductions in alcohol use and marijuana use were significant for the treatment group at the trend level. There were no significant differences in substance use from baseline to posttest for the control group. Findings demonstrate the potential of a brief motivational enhancement intervention to improve health risk behaviors in HIV-positive youth. Larger randomized clinical trials are warranted. Resources required for retention should not be underestimated. 相似文献
14.
We evaluated the effects of isoflurane anaesthesia and induced hypotension in 33 neurosurgical patients by electrocardiographic monitoring and serial cardiac enzyme measurements. An electrocardiogram (ECG) and serum enzymes were obtained preoperatively, intraoperatively and postoperatively in the recovery room and for three consecutive days. ECG leads II, V1 and V5 were monitored continuously during anaesthesia. Patients who had had a subarachnoid haemorrhage and a high incidence of abnormal preoperative ECG (42 per cent). Ten patients developed ECG changes intraoperatively, but these changes were unrelated to isoflurane-induced hypotension. Fifty-three per cent of patients developed an abnormal postoperative ECG. These abnormalities consisted mostly of nonspecific ST segment or T wave changes. At no time was there an elevation in cardiac enzyme activity. We found that nonspecific ECG changes are relatively common in patients undergoing vascular neurosurgical procedures. There was no enzymatic evidence of myocardial infarction and we can only speculate that these ECG changes are related to intracranial surgical manipulation. 相似文献
15.
We have produced and characterized a monoclonal antibody, MH1, which selectively labels rod horizontal cells and Müller cells in the goldfish retina. Biochemical and tissue distribution studies indicate that MH1 may recognize four out of five classes of intermediate filament proteins in goldfish: vimentin, desmin, glial fibrillary acidic protein (GFAP), and keratin, but not neurofilament. The intermediate filament which is labeled strongest in the retina is vimentin. In the goldfish retina, the only type of horizontal cells recognized by MH1 appear to be rod horizontal cells. This result suggests that the rod horizontal cell, an interneuron, and Müller (glial) cells share a common antigen: vimentin, which is usually only expressed in mesenchymal origin cells. The development of rod horizontal cells in the goldfish retina was also studied using MH1. The cells were not labeled by MH1 until 4-6 weeks posthatching, a stage in which the animals are already visually active. MH1 also did not label any horizontal cell in the region close to the ora terminalis in the goldfish retina. These results suggest that either the emergence and maturation of rod horizontal cells occur late during goldfish retinal development or the expression of vimentin itself occurs late in the development of rod horizontal cells. 相似文献
16.
17.
Adenosine is recommended for induction of deliberate hypotension. Although its effects on brain vasculature and metabolism and intracranial pressure have been reported, its effects on cerebrospinal fluid dynamics have not. In this study the rate of cerebrospinal fluid formation (Vf), resistance to reabsorption of cerebrospinal fluid (Ra), and electroencephalogram (EEG) activity were determined in rabbits before and during decrease of cerebral perfusion pressure (CPP) with intravenous (iv) adenosine or hemorrhage. In the adenosine group (n = 6), Vf and Ra were determined at control CPP, at CPP of 50, 35, and 28 mmHg achieved with iv adenosine, and at CPP greater than 60 mmHg achieved with iv adenosine combined with iv phenylephrine. In the hemorrhage group (n = 6), Vf and Ra were determined at the first four experimental conditions only. Control values for Vf (9 +/- 3 and 9 +/- 4 microliter.min-1, mean +/- SD) and Ra (428 +/- 567 and 412 +/- 144 cmH2O.ml-1.min) did not differ between groups. In the adenosine group, Vf did not change significantly when CPP was decreased. However, in the hemorrhage group, Vf decreased significantly at CPP of 50 and 35 mmHg and became unmeasurable at CPP of 28 mmHg. Ra did not change significantly in either group. An increase of low-frequency (0.5-3.0 Hz) EEG activity and/or decrease of higher-frequency (3.5-30 Hz) EEG activity occurred at CPP of 28 mmHg in the adenosine group and at CPP of 35 mmHg in the hemorrhage group.(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
18.
Erin E Michalak Edwin M Tam C V Manjunath Anthony J Levitt Robert D Levitan Raymond W Lam 《Revue canadienne de psychiatrie》2005,50(5):292-295
OBJECTIVE: To compare perceived quality of life (QoL) in patients diagnosed with seasonal affective disorder (SAD) during the winter and summer months. METHODS: Twenty-six patients who were enrolled in an ongoing multicentre study in Canada completed 2 measures of QoL (the 20-item Medical Outcomes Study Short-Form General Health Survey [SF-20] and the Quality of Life Enjoyment and Satisfaction Questionnaire, [Q-LES-Q]) during the winter, when suffering from depression, and again during the summer months. RESULTS: Both general and health-related QoL scores were significantly improved in patients with SAD during the summer months, with scores for the most part falling within normal range. CONCLUSIONS: Perceived QoL in patients with SAD is markedly impaired during the winter months but shows a substantial rebound during the summer months. The findings of this study provide further evidence that SAD is a distinct diagnostic entity. 相似文献
19.
Danny Lam RMN RNT PGCE Dip in GHGMR BSc BA MSc MA & Linda Cheng RMN RGN RMNS RNT BA Dip in Counselling Supervision 《Journal of advanced nursing》1998,27(6):1143-1150
Research shows that clients with automatic thoughts (dysfunctional thinking) often do not think of alternative explanations in relation to negative events. Furthermore, these automatic thoughts are characterized by a broad global, self-evaluative and ambiguous nature that could make disputing (or changing the ways they think) the most difficult part of the therapeutic process. This paper proposes a two-stage practise-based disputing model, guided by research, that aims to 'bring' an automatic thought to a specific, objective, quantifiable and concrete level at which not only is the particular aspect(s) of the automatic thought that causes emotional disturbances finely focused, but the disputing is also likely to be effective and manageable. Furthermore, it will also generate alternative explanations that are helpful in reducing emotional disturbances and in facilitating problem solving approach. In this paper, the authors use a case example to discuss the rationale that underpins the conceptualization of the model and to illustrate the process in which the strategies of the model are effectively used. 相似文献
20.