全文获取类型
收费全文 | 18516篇 |
免费 | 1177篇 |
国内免费 | 81篇 |
专业分类
耳鼻咽喉 | 172篇 |
儿科学 | 486篇 |
妇产科学 | 382篇 |
基础医学 | 2112篇 |
口腔科学 | 322篇 |
临床医学 | 1520篇 |
内科学 | 3908篇 |
皮肤病学 | 225篇 |
神经病学 | 1021篇 |
特种医学 | 526篇 |
外科学 | 3278篇 |
综合类 | 636篇 |
一般理论 | 17篇 |
预防医学 | 1422篇 |
眼科学 | 506篇 |
药学 | 1831篇 |
中国医学 | 218篇 |
肿瘤学 | 1192篇 |
出版年
2023年 | 169篇 |
2022年 | 515篇 |
2021年 | 650篇 |
2020年 | 420篇 |
2019年 | 527篇 |
2018年 | 636篇 |
2017年 | 442篇 |
2016年 | 359篇 |
2015年 | 499篇 |
2014年 | 690篇 |
2013年 | 860篇 |
2012年 | 1282篇 |
2011年 | 1261篇 |
2010年 | 734篇 |
2009年 | 560篇 |
2008年 | 988篇 |
2007年 | 979篇 |
2006年 | 912篇 |
2005年 | 839篇 |
2004年 | 767篇 |
2003年 | 688篇 |
2002年 | 579篇 |
2001年 | 543篇 |
2000年 | 485篇 |
1999年 | 390篇 |
1998年 | 143篇 |
1997年 | 114篇 |
1996年 | 107篇 |
1995年 | 116篇 |
1994年 | 60篇 |
1993年 | 75篇 |
1992年 | 202篇 |
1991年 | 186篇 |
1990年 | 163篇 |
1989年 | 171篇 |
1988年 | 134篇 |
1987年 | 153篇 |
1986年 | 123篇 |
1985年 | 134篇 |
1984年 | 110篇 |
1983年 | 86篇 |
1982年 | 59篇 |
1981年 | 60篇 |
1979年 | 97篇 |
1978年 | 64篇 |
1977年 | 66篇 |
1975年 | 60篇 |
1974年 | 51篇 |
1973年 | 54篇 |
1972年 | 50篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
31.
F C Thien B A Atkinson A Khan J M Mencia-Huerta T H Lee 《The Journal of allergy and clinical immunology》1992,89(4):829-835
We have studied the effect of dietary fish oil supplementation (3.2 gm/day of eicosapentaenoic acid and 2.2 gm/day of docosahexaenoic acid) for 10 weeks on the antigen-induced, cutaneous late-phase response (LPR) in 16 atopic individuals. All subjects developed an LPR to intradermal allergen injection. The mean +/- SEM area of induration at 6 hours was 1840 +/- 472 mm2. A biopsy was performed at the LPR site at 6 hours. Subjects were then randomized to receive fish oil or placebo olive oil in a double-blind, parallel fashion, for 10 weeks. After the diet, there were no significant differences between fish oil and placebo treatment in the size of the immediate wheal-and-flare response or the extent of induration at 4 and 6 hours, as compared with prediet values in each group. Histologically, at 6 hours, there was a significant infiltrate into the allergen site compared with that of the control diluent site of total inflammatory cells (p less than 0.002) as well as of eosinophils (p less than 0.001). However, there were no significant differences when pre- and postdiet values were compared. Hence, we conclude that dietary fish oil supplementation does not inhibit the cutaneous LPR clinically or histologically. 相似文献
32.
Nimodipine treatment in poor-grade aneurysm patients. Results of a multicenter double-blind placebo-controlled trial 总被引:4,自引:0,他引:4
K C Petruk M West G Mohr B K Weir B G Benoit F Gentili L B Disney M I Khan M Grace R O Holness 《Journal of neurosurgery》1988,68(4):505-517
A multicenter, randomized placebo-controlled double-blind trial of nimodipine in poor-grade aneurysm patients was carried out in 17 Canadian hospitals. Of 188 patients enrolled in the trial, 32 were excluded for protocol violations and two were excluded due to statistical considerations, leaving 154 patients for valid outcome analysis. Nimodipine treatment was associated with a significantly better outcome (p less than 0.001): 21 (29.2%) of 72 nimodipine-treated patients had a good outcome at 3 months after subarachnoid hemorrhage (SAH) compared to eight (9.8%) of 82 placebo-treated patients. Delayed ischemic deficits from vasospasm alone were significantly less frequent in the nimodipine group (p less than 0.05) with permanent deficits occurring in five nimodipine-treated patients (6.9%) and in 22 placebo-treated patients (26.8%). Improvement in the good outcome rate and reduction in delayed ischemic deficits from vasospasm alone occurred in both Grade 3 and 4 patients, with no difference between nimodipine- and placebo-treated patients being found in Grade 5 patients. Repeat angiography after Day 4 was carried out in 124 patients. There was no significant difference in the incidence of moderate or severe diffuse spasm, which was seen in 64.3% of nimodipine-treated patients and 66.2% of placebo-treated patients. The authors conclude that nimodipine treatment in poor-grade patients with SAH results in an increase in the number of good outcomes and a reduction in the incidence of delayed neurological deterioration due to vasospasm. This effect occurs by a mechanism other than prevention of large-vessel spasm as visualized on angiography. 相似文献
33.
34.
Ahsan Y Khan Joe Carrithers Sheldon H Preskorn Rex Lear Stephen R Wisniewski A John Rush Diane Stegman Colleen Kelley Karen Kreiner Andrew A Nierenberg Maurizio Fava 《Annals of clinical psychiatry》2006,18(2):91-98
BACKGROUND: The purpose of this paper is to use demographic and clinical data from a large diverse group of outpatients diagnosed with non-psychotic major depression to investigate the validity of the DSM-IV concept of melancholic depression. METHODS: Baseline clinical and demographic data were collected on 1500 outpatients (1456 of whom melancholia could be determined) with non-psychotic major depressive disorder (MDD) participating in the Sequenced Treatment Alternatives to Relieve Depression (STAR*D) study. Depressive symptom severity was assessed by clinical telephone interview using the 17-item Hamilton Rating Scale for Depression (HRS-D17) and the 30-item Inventory of Depressive Symptomatology (IDS-C30). The types and degrees of concurrent psychiatric symptoms were measured using a self report, the Psychiatric Diagnostic Screening Questionnaire (PDSQ), by recording the number of items relevant to each diagnostic category endorsed by study participants. RESULTS: Adjusting for severity of depression (as measured by the total HRS-D17 scores), no differences were found in the rate of melancholic depression by race, marital status, education, employment status, family history of depression, primary care versus specialty care, monthly income, and degree of psychiatric and medical co-morbidity. Melancholic depression was significantly more likely in men than women. Melancholic depression after adjustment for severity was associated with a slightly younger age at study entry, as well as with greater illness severity, and slightly shorter duration of current episode. Hispanic ethnicity was associated with lower melancholic depression rates at the .06 level of significance. CONCLUSIONS: Among outpatients with MDD, melancholic features were less likely in Hispanic patients, but more likely in slightly younger patients and in men. Melancholic features were also related to a slightly shorter current episode. These findings are consistent with the notion that external socio-demographic factors do not play an important role in the pathophysiology of melancholic depression. 相似文献
35.
Duane retraction syndrome has been reported in association with structural abnormalities of the eye, including epibulbar dermoid, keratoconus, iris dysplasia, heterochromia iridis, persistent fetal vasculature, cataract, choroidal coloboma, microphthalmia, and optic nerve dysplasia. A novel association, that of bilateral Duane syndrome with bilateral aniridia, is the subject of this report. 相似文献
36.
37.
Ganesh Shanmugam Sumit Bhutani David A Khan E Sherwood Brown 《The Psychiatric clinics of North America》2007,30(4):761-780
Lung disease is a prominent cause of morbidity and mortality worldwide. When a patient has a common lung disease, such as asthma, or a less prevalent one, such as idiopathic pulmonary fibrosis, psychiatric issues should be considered as an integral part of the care plan for each patient. There have been many studies of psychologic factors and psychiatric syndromes in various lung diseases and their treatment. In this article, the authors focus on an evidence-based approach to reviewing this clinical literature. 相似文献
38.
Children with severe neurological impairment have a high incidence of respiratory problems which are multifactorial and may be related to or dependent on the underlying disability. In addition, common respiratory conditions such as asthma will be represented in this group as in the general paediatric population. In order to maximise quality of life and reduce morbidity and mortality, each child should be carefully assessed and treated, making adjustments where necessary in the treatment regime to take account of the disability. 相似文献
39.
Glatiramer acetate is an immunomodulating drug used in the treatment of multiple sclerosis. It consists of a copolymer of amino acid residues in the same stoichiometric proportions as in myelin basic protein. Its mechanism of action is not entirely known and is probably multifaceted, with deletion of some immune cell populations and stimulation of others in these patients. Some mechanisms involve neuroprotectant effects. There is ample evidence of its efficacy in relapsing-remitting disease, using both clinical and imaging measures of disease activity, and in this paper we review the clinical and basic studies of this drug. Finally we discuss how some of its neuroprotectant effects may be useful in neurodegeneration such as is seen in more advanced cases of multiple sclerosis and other diseases such as amyotrophic lateral sclerosis and Parkinson’s disease. 相似文献
40.
BACKGROUND: We assessed suicide and suicide attempt risk as well as symptom reduction among 3,282 depressed patients participating in duloxetine and escitalopram clinical trials assigned to either an antidepressant or placebo. METHODS: We reviewed the FDA Summary Basis of Approval reports for data regarding safety and efficacy for duloxetine and escitalopram. Furthermore, we compared suicide risk among antidepressant clinical trials in this study with our two previous analyses on seven antidepressant clinical trials. RESULTS: Suicide and suicide attempt risk varied considerably among the three analyses, showing up to ten fold differences. Interestingly, the variability exists across the three reports, rather than between treatments (antidepressants versus placebo). CONCLUSIONS: These findings suggest caution in generalizing suicide risk even from a relatively large number of participants and thus, firm conclusions can only be drawn if the number of participants is overwhelmingly large (approximately two million patients). We also noted similar magnitude of response to placebo and antidepressants among the three studies. 相似文献