全文获取类型
收费全文 | 16328篇 |
免费 | 1458篇 |
国内免费 | 35篇 |
专业分类
耳鼻咽喉 | 115篇 |
儿科学 | 426篇 |
妇产科学 | 421篇 |
基础医学 | 2380篇 |
口腔科学 | 395篇 |
临床医学 | 1572篇 |
内科学 | 3652篇 |
皮肤病学 | 181篇 |
神经病学 | 1771篇 |
特种医学 | 651篇 |
外国民族医学 | 1篇 |
外科学 | 1878篇 |
综合类 | 276篇 |
一般理论 | 12篇 |
预防医学 | 1512篇 |
眼科学 | 431篇 |
药学 | 1309篇 |
1篇 | |
中国医学 | 17篇 |
肿瘤学 | 820篇 |
出版年
2022年 | 117篇 |
2021年 | 280篇 |
2020年 | 167篇 |
2019年 | 264篇 |
2018年 | 293篇 |
2017年 | 206篇 |
2016年 | 224篇 |
2015年 | 249篇 |
2014年 | 344篇 |
2013年 | 575篇 |
2012年 | 747篇 |
2011年 | 843篇 |
2010年 | 468篇 |
2009年 | 440篇 |
2008年 | 741篇 |
2007年 | 824篇 |
2006年 | 803篇 |
2005年 | 846篇 |
2004年 | 717篇 |
2003年 | 675篇 |
2002年 | 665篇 |
2001年 | 452篇 |
2000年 | 449篇 |
1999年 | 421篇 |
1998年 | 252篇 |
1997年 | 192篇 |
1996年 | 161篇 |
1995年 | 143篇 |
1994年 | 134篇 |
1993年 | 142篇 |
1992年 | 333篇 |
1991年 | 314篇 |
1990年 | 312篇 |
1989年 | 269篇 |
1988年 | 239篇 |
1987年 | 232篇 |
1986年 | 207篇 |
1985年 | 205篇 |
1984年 | 168篇 |
1983年 | 176篇 |
1982年 | 120篇 |
1981年 | 124篇 |
1979年 | 157篇 |
1978年 | 136篇 |
1977年 | 125篇 |
1976年 | 132篇 |
1975年 | 124篇 |
1974年 | 120篇 |
1973年 | 127篇 |
1972年 | 110篇 |
排序方式: 共有10000条查询结果,搜索用时 312 毫秒
71.
C Ambrose M James G Barnes C Lin G Bates M Altherr M Duyao N Groot D Church J J Wasmuth 《Human molecular genetics》1992,1(9):697-703
Within the Huntington's disease (HD) candidate region of 4p16.3, the D4S127 locus displays strong linkage disequilibrium with the defect and anchors a conserved haplotype found on many HD chromosomes. To isolate genes from this region we have applied the exon amplification technique to overlapping cosmids spanning D4S127. Here, we report the discovery of a new gene encoding a novel member of a family of protein kinases that specifically phosphorylate the activated forms of G protein-coupled receptors. Such kinases are thought to participate in desensitization of specific receptors, thereby blocking further signal transduction. This gene must now be carefully scrutinized to determine whether it might be involved in HD. 相似文献
72.
The post-mortem diagnosis of acute myocardial ischaemia may be difficult to establish in the absence of morphological changes in the myocardium or recent coronary thrombosis. Ischaemic cell injury leads to potassium (K) efflux and sodium (Na) influx and, if the blood is still circulating, the K:Na ratio of the tissue falls. In this study, the K:Na ratio was measured by eluting the ions from samples of myocardium and assaying the eluate. The method yields similar results to those obtained by a previous method, in which myocardial samples were homogenized. The K:Na ratios on samples of horizontal slices through the heart were plotted on maps of the slices. A low K:Na ratio corresponded to, but extended beyond, areas where there was morphological evidence of ischaemia. The method is simple and may be of use in routine practice. 相似文献
73.
74.
75.
Regulation of histamine H1 receptor-mediated phosphoinositide hydrolysis by histamine and phorbol esters in DDT1 MF-2 cells 总被引:5,自引:0,他引:5
The regulation of histamine-stimulated phosphoinositide turnover by histamine and phorbol esters was examined in intact DDT1 MF-2 cells grown in suspension culture. Histamine increased the incorporation of 32P into phosphatidylinositol (PI) in these cells, and this stimulation was inhibited by the H1 antagonist diphenhydramine but not by the H2 antagonist cimetidine. Pretreatment of cells with histamine or with phorbol 12-myristate 13-acetate (PMA) or other activators of protein kinase C induced a marked decrease in the subsequent stimulation by histamine. PMA, but not histamine, also decreased the ability of epinephrine to stimulate PI labelling through alpha 1-adrenoceptors. Thus, histamine appears to induce homologous desensitization of histamine H1 receptor-mediated PI turnover, whereas direct activation of protein kinase C in the absence of receptor occupancy by agonist induces nonspecific heterologous desensitization of both histamine H1- and alpha 1-adrenoceptor-mediated responses. 相似文献
76.
A. C. Leon M. Katherine Shear Laura Portera G. L. Klerman 《Social psychiatry and psychiatric epidemiology》1992,27(2):78-82
Summary The DSM-III-R incorporates both distress (symptoms) and disability (impairment) in the definition of a psychiatric disorder. In psychiatric research there is a wide array of instruments used to measure symptom severity, but a limited selection for the assessment of impairment. The psychometric properties of one such instrument, The Sheehan Disability Scale (Sheehan 1983), are evaluated in this paper. The data analyzed come from two studies of patients with panic disorder, the Cross National Collaborative Panic Study-Phase I and the Panic Depression Study. In this report both the alpha coefficients and factor analyses indicate that the reliability of the scale is acceptable. The factor structure of the items and the sensitivity to change of their composite demonstrate satisfactory construct validity. The criterion-related validity is substantiated by the significant relationship between symptomatology and impairment. These analyses were limited to patients with panic disorder. Further work is needed to evaluate the instrument in assessing patients with other disorders. 相似文献
77.
K Tardiff P M Marzuk A C Leon C S Hirsch M Stajic L Portera N Hartwell 《Public health reports (Washington, D.C. : 1974)》1995,110(1):13-17
Although prior research has found that homes containing firearms and illicit drug and ethanol users are more likely to be the scene of a homicide than homes that do not contain these elements, the authors studied homicides on the streets as well as in homes so as to assess the role of firearms, cocaine, and ethanol in both settings. Using the files of the Chief Medical Examiner, the authors reviewed all 4,468 homicides occurring in New York City in 1990 and 1991. The most frequent places of occurrence were the streets and other outdoor places (49.6 percent) and the victims'' homes (19.3 percent). Firearms were the cause of death for 49.6 percent of homicides in the home and 80.3 percent of those on the streets. Use of cocaine and ethanol was found more frequently among victims killed on the streets than those killed at home. In addition, victims killed on the streets were more likely to be male, ages 15-24 years, and African American. Further research in regard to prevention and intervention strategies is needed, keeping in mind the different patterns of homicide on the streets compared with those occurring in other settings. 相似文献
78.
The authors previously described a method of windowing the femur that allowed good exposure for femoral cement removal and provided for reconstruction of the defect. Since that report, they have developed instrumentation to facilitate windowing of the femoral shaft. They describe its use in this report. 相似文献
79.
Leon A. Weisberg Jack Greenberg Antonio Stazio 《Computerized medical imaging and graphics》1988,12(6):379-383
The clinical and computerized tomographic (CT) findings in 10 patients with cerebral toxoplasmosis are reviewed. All patients with cerebral toxoplasmosis were homosexuals and/or intravenous drug users, and all patients had other manifestations of AIDS. Two presented with focal seizures, 4 presented with focal neurological deficit which progressively worsened, and 4 had evidence of diffuse neurological dysfunction (altered consciousness, generalized seizures). CT showed a single lesion in 3 patients and multiple lesions in 7 patients. Two patients had hypodense nonenhancing lesions(s). Eight patients had hypodense lesions with peripheral or nodular enhancement. The lesions were more commonly located in the cerebral hemispheres and subcortical gray matter nuclear masses (thalamus, basal ganglia). The finding of a hypodense lesion with a central slightly hyperdense noncalcified region that showed dense nodular homogeneous enhancement was quite characteristic of cerebral toxoplasmosis, but this pattern may also be seen in other neurological conditions including brain lymphomas. 相似文献
80.
Michiel A. M. Feldberg M.D. Ph.D. Leon P. Driessen Theo D. Witkamp Maarten S. van Leeuwen Paul F. G. M. van Waes 《Urologic radiology》1988,10(1):92-94
In a case of diffuse xanthogranulomatous pyelonephritis, computed tomography (CT) and magnetic resonance (MR) were used. The MR proved to be more precise in the preoperative evaluation of inflammatory extension to the spleen and into the abdominal wall. The CT was more accurate in excluding spread to the colon. 相似文献