全文获取类型
收费全文 | 1266篇 |
免费 | 86篇 |
国内免费 | 67篇 |
专业分类
耳鼻咽喉 | 5篇 |
儿科学 | 52篇 |
妇产科学 | 25篇 |
基础医学 | 187篇 |
口腔科学 | 28篇 |
临床医学 | 141篇 |
内科学 | 346篇 |
皮肤病学 | 33篇 |
神经病学 | 65篇 |
特种医学 | 90篇 |
外科学 | 117篇 |
综合类 | 20篇 |
预防医学 | 132篇 |
眼科学 | 7篇 |
药学 | 121篇 |
中国医学 | 3篇 |
肿瘤学 | 47篇 |
出版年
2023年 | 11篇 |
2022年 | 24篇 |
2021年 | 22篇 |
2020年 | 18篇 |
2019年 | 29篇 |
2018年 | 41篇 |
2017年 | 24篇 |
2016年 | 37篇 |
2015年 | 34篇 |
2014年 | 54篇 |
2013年 | 58篇 |
2012年 | 68篇 |
2011年 | 88篇 |
2010年 | 59篇 |
2009年 | 53篇 |
2008年 | 72篇 |
2007年 | 99篇 |
2006年 | 55篇 |
2005年 | 44篇 |
2004年 | 41篇 |
2003年 | 33篇 |
2002年 | 26篇 |
2001年 | 18篇 |
2000年 | 15篇 |
1999年 | 25篇 |
1998年 | 40篇 |
1997年 | 41篇 |
1996年 | 30篇 |
1995年 | 23篇 |
1994年 | 30篇 |
1993年 | 20篇 |
1992年 | 10篇 |
1991年 | 12篇 |
1990年 | 5篇 |
1989年 | 20篇 |
1988年 | 21篇 |
1987年 | 14篇 |
1986年 | 5篇 |
1985年 | 13篇 |
1984年 | 10篇 |
1983年 | 6篇 |
1982年 | 12篇 |
1981年 | 12篇 |
1980年 | 8篇 |
1978年 | 8篇 |
1977年 | 9篇 |
1976年 | 10篇 |
1975年 | 6篇 |
1966年 | 1篇 |
1957年 | 1篇 |
排序方式: 共有1419条查询结果,搜索用时 31 毫秒
1.
Alcohol use among Hispanic groups in the United States 总被引:3,自引:0,他引:3
R Caetano 《The American journal of drug and alcohol abuse》1988,14(3):293-308
2.
3.
R Caetano 《Journal of studies on alcohol》1987,48(2):153-160
Survey respondents' views about alcoholism as an illness, support for treatment, treatment recommendation and stigma surrounding alcoholics are examined. Subjects (N = 482) comprise a random sample of the population of Contra Costa County, California. About 91% of the respondents agree with the notion that alcoholism is an illness, but 40% also agree that alcoholics drink because they want to. More women than men support the idea that to recover alcoholics will have to quit drinking forever. The contrary is true of the idea of controlled drinking. Education and income are negatively associated with items on loss of control and controlled drinking. Respondents who have had their lives deeply affected by an alcoholic and those who report a drinking problem of their own do not differ in their opinions about alcoholism from those who do not have these characteristics. Alcoholics Anonymous is the most common form of treatment recommended by the respondents. In general, results show considerable support for treatment as well as ambivalence regarding the disease concept. 相似文献
4.
Balloon dacryocystoplasty: indications and contraindications 总被引:3,自引:0,他引:3
5.
Nuno Fonseca Filomena Caetano José Santos Filipe Seixo Leonel Bernardino Isabel Silvestre Paula Cardoso Filomena Segurado Lopes Inês 《Revista portuguesa de cardiologia》2004,23(3):365-375
INTRODUCTION: In patients (pts) with atrial fibrillation (AF) of more than 48 hours' duration, electrical cardioversion (ECV) should only be performed after 3 weeks of effective anticoagulation. Transesophageal echocardiography (TEE) allows earlier ECV; however, despite exclusion of thrombi in the atrium and left atrial appendage (LAA), cases of thromboembolism related to ECV have been documented in AF. To define a low-risk group for cardioversion without previous anticoagulation, pts were selected for immediate ECV if no thrombi or dynamic spontaneous echo contrast (auto-contrast) were found after TEE and if LAA velocity was more than 0.25 m/sec. METHODS AND RESULTS: We performed TEE in 31 consecutive pts referred for ECV for AF of more than 48 hours' duration and without previous anticoagulation. After TEE the pts eligible for immediate ECV began anticoagulation with low molecular weight heparin (enoxaparin), subcutaneously in therapeutic doses, together with warfarin immediately before cardioversion. Enoxaparin was continued until an INR of over 2 was reached. Based on the TEE findings, the pts were divided in 2 groups: immediate ECV, group A, 20 pts with a mean age of 62 +/- 13 years, 6 female; and conventional therapy with warfarin before ECV, group B, 11 pts, mean age of 67 +/- 10 years (p < 0.05), 2 female. None of the pts in either group had mitral stenosis or previous episodes of thromboembolism. The mean transverse diameter of the left atrium in the 31 pts was 47 +/- 4.5 mm, without statistically significant differences between the 2 groups. Of the 11 pts in group B, 3 had a thrombus in the LAA, 6 dynamic spontaneous echo contrast and the remainder LAA velocities of less than 0.25 m/sec. ECV was achieved in all the pts, with no complications. Oral anticoagulation was maintained for at least a month. At one month, sinus rhythm was maintained in 75% of group A and 45% of group B (p < 0.01). CONCLUSION: In pts with AF of more than 48 hours' duration and no previous history of thromboembolism, the use of our exclusion criteria during TEE enabled stratification of a low-risk population for immediate ECV, which was accomplished effectively and safely in 2/3 of the pts. This strategy is associated with early symptomatic improvement, and may contribute to maintenance of sinus rhythm after one month, which was significantly better than in the pts who had prolonged therapy with warfarin before ECV, despite the differences found in age and left ventricular function. 相似文献
6.
7.
Duncan WC; Illingworth PJ; Young FM; Fraser HM 《Human reproduction (Oxford, England)》1998,13(9):2532-2540
The molecular mechanisms involved in luteolysis are still unclear in the
primate. This study aimed to investigate the effect of induced luteolysis
on the ovarian luteinizing hormone (LH) receptor and the steroidogenic
enzyme, 3beta-hydroxysteroid dehydrogenase (3beta-HSD) in the marmoset
monkey. Luteolysis was induced in the mid-luteal phase either directly by
systemic prostaglandin F2alpha (PGF2alpha), or indirectly by LH withdrawal
using systemic gonadotrophin releasing hormone antagonist (GnRHant)
treatment. The LH receptor was studied by isotopic mRNA in-situ
hybridization and in-situ ligand binding and 3beta-HSD expression was
studied using isotopic mRNA in-situ hybridization and immunohistochemistry.
Induced luteolysis was associated with a reduction in the expression of LH
receptor (P < 0.0001) and 3beta-HSD mRNA, closely followed by a
reduction in the LH receptor (P < 0.05) and 3beta-HSD protein
concentrations within 24 h. There were no differences in the findings
whether luteolysis was induced with PGF2alpha or GnRHant. This study shows
that disparate mechanisms to induce luteolysis in the primate result in an
identical rapid loss of the LH receptor and 3beta-HSD. In conclusion,
induced luteolysis leads to rapid loss of the steroidogenic pathway in
luteal cells.
相似文献
8.
HM Clink 《Journal of clinical pathology》1980,33(8):799-800
9.
10.
Proton spectroscopy study of the left dorsolateral prefrontal cortex in pediatric depressed patients
Caetano SC Fonseca M Olvera RL Nicoletti M Hatch JP Stanley JA Hunter K Lafer B Pliszka SR Soares JC 《Neuroscience letters》2005,384(3):321-326
The dorsolateral prefrontal cortex (DLPFC) plays an essential role in mood regulation and integration of cognitive functions that are abnormal in major depressive disorder (MDD). Few neuroimaging studies have evaluated the still maturing DLPFC in depressed children and adolescents. We conducted single voxel proton magnetic resonance spectroscopy ((1)H MRS) of the left DLPFC in 14 depressed children and adolescents (13.3 +/- 2.3 years old, 10 males) and 22 matched healthy controls (13.6 +/- 2.8 years old, 13 males). Depressed subjects had significantly lower levels of glycerophosphocholine plus phosphocholine (GPC + PC; or choline-containing compounds) and higher myo-inositol levels in the left DLPFC compared to healthy controls. In the depressed subjects, we found significant inverse correlations between glutamate levels and both duration of illness and number of episodes. In healthy controls there was a significant direct correlation between age and glutamine levels, which was not present in the patient group. Lower GPC + PC levels in pediatric MDD may reflect lower cell membrane content per volume in the DLPFC. Increased myo-inositol levels in MDD may represent a disturbed secondary messenger system. GPC + PC and myo-inositol abnormalities further demonstrate the involvement of DLPFC in pediatric MDD. 相似文献