全文获取类型
收费全文 | 210446篇 |
免费 | 4927篇 |
国内免费 | 513篇 |
专业分类
耳鼻咽喉 | 3006篇 |
儿科学 | 7673篇 |
妇产科学 | 6127篇 |
基础医学 | 27311篇 |
口腔科学 | 7711篇 |
临床医学 | 16342篇 |
内科学 | 38155篇 |
皮肤病学 | 4951篇 |
神经病学 | 12928篇 |
特种医学 | 11057篇 |
外国民族医学 | 97篇 |
外科学 | 30632篇 |
综合类 | 1140篇 |
一般理论 | 7篇 |
预防医学 | 18009篇 |
眼科学 | 4612篇 |
药学 | 14706篇 |
2篇 | |
中国医学 | 311篇 |
肿瘤学 | 11109篇 |
出版年
2021年 | 791篇 |
2019年 | 683篇 |
2018年 | 4198篇 |
2017年 | 4337篇 |
2016年 | 3673篇 |
2015年 | 5366篇 |
2014年 | 4981篇 |
2013年 | 4307篇 |
2012年 | 11105篇 |
2011年 | 6084篇 |
2010年 | 2972篇 |
2009年 | 4394篇 |
2008年 | 2922篇 |
2007年 | 3653篇 |
2006年 | 3810篇 |
2005年 | 11836篇 |
2004年 | 13243篇 |
2003年 | 8706篇 |
2002年 | 3855篇 |
2001年 | 4629篇 |
2000年 | 1950篇 |
1999年 | 6035篇 |
1992年 | 6919篇 |
1991年 | 7197篇 |
1990年 | 7422篇 |
1989年 | 7030篇 |
1988年 | 6544篇 |
1987年 | 6300篇 |
1986年 | 5992篇 |
1985年 | 5289篇 |
1984年 | 3628篇 |
1983年 | 2938篇 |
1982年 | 1034篇 |
1981年 | 795篇 |
1980年 | 865篇 |
1979年 | 3860篇 |
1978年 | 2385篇 |
1977年 | 1800篇 |
1976年 | 1572篇 |
1975年 | 2496篇 |
1974年 | 3140篇 |
1973年 | 2759篇 |
1972年 | 2764篇 |
1971年 | 2758篇 |
1970年 | 2564篇 |
1969年 | 2477篇 |
1968年 | 2245篇 |
1967年 | 2175篇 |
1966年 | 1911篇 |
1965年 | 1134篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
81.
Irradiation of a cytosolic fraction from vascular smooth muscle in the presence of [3H]felodipine resulted in the labelling of a protein with an apparent molecular weight of 62 kDa. The labelling was seen on UV-irradiation at 360 nm, but not at 254, 278 or at wavelengths above 410 nm. The photolabelling was enhanced in the absence of oxygen. In cytosolic fractions prepared from porcine liver, cardiac and skeletal muscle no photoaffinity labelling of proteins between 90 and 45 kDa could be demonstrated. The results suggest that felodipine is a photoaffinity ligand and that felodipine binds to a soluble protein present in vascular smooth muscle but not in the other tissues tested. 相似文献
82.
A new technique for ultrasonic examination of the hip joint was evaluated in neonatals and infants. An anterior approach was used with the sound sector centered over the femoral head and parallel to the femoral neck. The ultrasonograms corresponded to lateral radiographs of the joint with the leg in Lorenz' first position. It was possible to evaluate the size and depth of the acetabulum and the size and position of the femoral head. The projection also permitted a dynamic examination for determination of hip instability. Thus, the technique provided a method for an objective diagnosis in congenital dislocation of the hip (CDH). In 216 hips, the results of clinical evaluation for CDH were correlated with the degree of instability demonstrated by ultrasound. The comparison showed the clinical diagnosis to be highly inaccurate. 相似文献
83.
84.
Erja Wiili-Peltola Mika Kivim?ki Marko Elovainio Marianna Virtanen 《Journal of health organization and management》2007,21(2-3):320-332
PURPOSE: The purpose to clarify what kind of managerial challenges employees experience regarding organisational justice in hospitals. DESIGN/METHODOLOGY/APPROACH: This exploratory study of 8,971 employees working in 14 hospitals and examines the concept of organisational justice in management with qualitative and quantitative methods. FINDINGS: An inductive content analysis of the comments revealed five integrative frames describing challenges in hospital management at respondents' workplaces. These frames should be regarded as major managerial challenges in hospitals. These findings illustrate important antecedents of organisational justice and suggest that work units tend to share the same perceptions of justice. They also reveal that individually produced comments reflect collective experiences in organisational justice. Further, the results indicate that problems in management and policies are often experienced in a complex way, and people making justice judgements do not separate procedural and interactional factors. RESEARCH LIMITATIONS/IMPLICATIONS: Although the commentators producing qualitative data represented many organisational hierarchy levels, the results should not be generalised to apply to horizontal, informal social relationships. PRACTICAL IMPLICATIONS: This paper gives useful information regarding challenges in human resources management in hospitals. ORIGINALITY/VALUE: The paper suggests that people making fairness judgements do not make a distinction between procedural and interpersonal factors. Instead, they use any information available to judge the righteousness of the management events. This paper serves to guide hospital managers towards a better understanding of the importance of organisational justice and its collective nature. 相似文献
85.
In 50 children, 4 months to 12 years of age, with minor head trauma non-target visual event-related potentials were performed and compared to a second registration of the potentials some months later. On following-up there was a clear tendency for a relative improvement of the latencies of the endogenous potentials. In this way non-target visual event-related potentials proved to be of value in the investigation of mental impairment in early childhood. 相似文献
86.
Extracellular pH in the brain during ischemia: relationship to the severity of lactic acidosis 总被引:2,自引:0,他引:2
K Katsura A Ekholm B Asplund B K Siesj? 《Journal of cerebral blood flow and metabolism》1991,11(4):597-599
On the basis of data showing a bimodal distribution of values for extracellular pH (pHe), and a discontinuous delta PCO2/delta lactate relationship, Kraig et al. (1986) proposed that H+ is grossly compartmentalized between neurons and glia in the ischemic brain. We measured delta pHe during ischemia, varying ischemic lactate contents between 9 and 38 mmol kg-1. No bimodal distribution was found, but delta pHe varied linearly with lactate content. Because we have also failed to record a discontinuous delta PCO2/delta lactate relationship, we conclude that major compartmentation of H+ does not occur during ischemia. 相似文献
87.
88.
Trypsin and Zymosan induce an increase in respiration activity of cultivated endothelial cells. These effects are not due to the production of oxygen radicals. The effect of trypsin will be explained by interfering with the cellular homeostasis of calcium. The stimulated respiration after incubation with zymosan may be connected with the increased phagocytosis. 相似文献
89.
32nd Annual Meeting of the Scandinavian Society for Psychopharmacology Copenhagen, Denmark April 10–12, 1991 Abstracts 相似文献
90.
Synaptic contacts between growth hormone-releasing hormone (GHRH)- and somatostatin-containing neurons were demonstrated in the rat hypothalamus by a double-staining immunocytochemical method at the electron microscopic level. Somatostatin-immunoreactive nerve terminals synapse on GHRH-positive dendrites and cell bodies in the arcuate nucleus. A fine network of GHRH-immunopositive nerve terminals was observed at the light microscopic level in the rostral part of the periventricular nucleus and in the dorsal part of the arcuate nucleus around somatostatin-containing neuronal elements. With the electron microscope synaptic contact between GHRH-containing nerve terminals and somatostatin-containing dendrites are demonstrated. The reciprocal innervation between GHRH- and somatostatin-containing neurons that project to the median eminence and regulate growth hormone secretion must allow them to coordinate their activities. 相似文献