全文获取类型
收费全文 | 684篇 |
免费 | 59篇 |
国内免费 | 9篇 |
专业分类
耳鼻咽喉 | 1篇 |
儿科学 | 32篇 |
妇产科学 | 4篇 |
基础医学 | 62篇 |
口腔科学 | 34篇 |
临床医学 | 60篇 |
内科学 | 158篇 |
皮肤病学 | 20篇 |
神经病学 | 46篇 |
特种医学 | 131篇 |
外科学 | 45篇 |
综合类 | 76篇 |
预防医学 | 17篇 |
药学 | 37篇 |
1篇 | |
肿瘤学 | 28篇 |
出版年
2022年 | 1篇 |
2021年 | 5篇 |
2020年 | 3篇 |
2019年 | 4篇 |
2018年 | 11篇 |
2017年 | 8篇 |
2016年 | 10篇 |
2015年 | 14篇 |
2014年 | 17篇 |
2013年 | 17篇 |
2012年 | 14篇 |
2011年 | 11篇 |
2010年 | 22篇 |
2009年 | 28篇 |
2008年 | 14篇 |
2007年 | 15篇 |
2006年 | 33篇 |
2005年 | 15篇 |
2004年 | 12篇 |
2003年 | 16篇 |
2002年 | 10篇 |
2001年 | 15篇 |
2000年 | 9篇 |
1999年 | 8篇 |
1998年 | 32篇 |
1997年 | 51篇 |
1996年 | 47篇 |
1995年 | 33篇 |
1994年 | 33篇 |
1993年 | 37篇 |
1992年 | 21篇 |
1991年 | 10篇 |
1990年 | 15篇 |
1989年 | 15篇 |
1988年 | 20篇 |
1987年 | 9篇 |
1986年 | 6篇 |
1985年 | 8篇 |
1984年 | 9篇 |
1983年 | 12篇 |
1982年 | 16篇 |
1981年 | 15篇 |
1980年 | 10篇 |
1979年 | 5篇 |
1978年 | 4篇 |
1977年 | 6篇 |
1976年 | 15篇 |
1975年 | 9篇 |
1973年 | 1篇 |
1971年 | 1篇 |
排序方式: 共有752条查询结果,搜索用时 15 毫秒
81.
Snyder DS; Negrin RS; O'Donnell MR; Chao NJ; Amylon MD; Long GD; Nademanee AP; Stein AS; Parker PM; Smith EP 《Blood》1994,84(5):1672-1679
Ninety-four consecutive patients with chronic myelogenous leukemia in first clinical chronic phase, median age of 34.0 years (range, 6.8 to 52.4 years), with a histocompatible sibling donor, were treated with fractionated total body irradiation (1,320 cGy) and high-dose etoposide (60 mg/kg) followed by allogeneic bone marrow transplantation (BMT). The median time from diagnosis to BMT was 7.0 months (range, 2.3 to 72.0 months). Sixty patients were treated before BMT with hydroxyurea alone, four patients with busulfan alone, one patient with interferon alone, and the other 29 patients were treated with various combinations of these drugs. Cumulative probabilities of overall survival, event- free survival, and relapse at 5 years were 73%, 64%, and 14%, respectively. The median follow-up time for surviving patients was 38 months, ranging from 12 to 88 months. By stepwise Cox regression analysis, significant prognostic variables were age at transplant, acute graft-versus-host disease > or = grade II, cytomegalovirus- associated interstitial pneumonitis, and years from diagnosis to BMT. 相似文献
82.
Chronic myelocytic leukemia (CML) is a clonal disorder involving neutrophil, monocyte, erythrocyte, and platelet precursors. In order to determine if the eosinophils are also involved in the leukemic clone, we purified the eosinophils from a woman heterozygous for the common electrophoretic variants of the G6PD gene. Only type B enzyme was demonstrable in the eosinophils, neutrophils, and red cells, but both A and B enzymes were found in the fibroblasts. The data provide evidence that the eosinophil is involved in the malignant clone. 相似文献
83.
Effects of fibroblast growth factor-4 (k-FGF) on long-term cultures of human bone marrow cells 总被引:1,自引:0,他引:1
Fibroblast growth factor-4 (FGF-4), a highly mitogenic protein encoded by the k-fgf/hst oncogene, stimulates the growth of a variety of cells of mesenchymal and neuroectodermal origin. Addition of FGF-4 to human long-term bone marrow cultures increased both the cell density of the stromal layer and the number of hematopoietic colony forming cells in the cultures in a dose-dependent manner. Hematopoiesis in the stromal layer persisted for up to 8 months. Erythropoiesis was maintained for up to 4 weeks, but granulocytes were the predominant nonadherent cell type. Cultures treated with FGF had increased numbers of monocytes compared with control cultures and some CD14+, CD45+ monocytes could still be detected after 8 months of continuous culture. The addition of the growth factor increased the rate of growth of the stromal layer and appeared to delay its senescence. Subcultures made in the presence of FGF-4 had up to 10-fold increases in plating efficiency and grew as relatively uniform monolayers. These subcultures retained the capacity to support hematopoiesis for several months, while untreated subcultures, made without FGF-4, grew erratically and generally lost the capacity to support hematopoiesis within 4 to 6 weeks. The improved growth after subculture greatly enhanced the reliability of limit- dilution assays of multipotential hematopoietic stem cells that use stromal cell monolayers. The primary effect of FGF-4 appeared to be on the stromal cells of the long-term bone marrow cultures, but a direct effect on hematopoietic progenitors could not be ruled out. 相似文献
84.
Prior studies have shown that pneumothorax is one of the more difficult entities to diagnose with digitized radiography. This study was designed to test whether increasing resolution from 1.25 to 2.5 line pairs per millimeter (lp/mm) and image processing (edge enhancement from unsharp masking) would increase accuracy and confidence in the diagnosis of pneumothorax, as well as normal cases and other forms of lung disease. Conventional radiographs were digitized with use of a laser reader and then reformatted as film hard copy. Eleven observers read 35 cases reformatted in three different ways (1.25 lp/mm, 2.5 lp/mm, 1.25 lp/mm unsharp mask). The images with finer resolution (2.5 lp/mm) and unsharp mask images were superior to those with coarser resolution (1.25 lp/mm) for the diagnosis of pneumothorax. There was no difference in diagnostic accuracy for normal patients. For abnormalities other than pneumothorax, the unsharp mask images were significantly worse. Confidence in the diagnosis of pneumothorax and other abnormalities was highest with the finest resolution (2.5 lp/mm). 相似文献
85.
86.
MJ McKinley RM McAllen GL Pennington A. Smardencas RS Weisinger BJ Oldfield 《Clinical and experimental pharmacology & physiology》1996,23(Z3):99-104
- 1 Autoradiographic binding studies have shown that the AT1 receptor is the predominant angiotensin II (AngII) receptor subtype in the central nervous system (CNS). Major sites of AT1 receptors are the lamina terminalis, hypothalamic paraventricular nucleus, the lateral parabrachial nucleus, rostral and caudal ventrolateral medulla, nucleus of the solitary tract and the intermediolateral cell column of the thoraco-lumbar spinal cord.
- 2 While there are differences between species, AT2 receptors are found mainly in the cerebellum, inferior olive and locus coeruleus of the rat.
- 3 Circulating AngII acts on AT1 receptors in the subfornical organ and organum vasculosum of the lamina terminalis (OVLT) to stimulate neurons that may have a role in initiating water drinking.
- 4 Centrally administered AngII may act on AT1 receptors in the median preoptic nucleus and elsewhere to induce drinking, sodium appetite, a sympathetic vasoconstrictor response and vasopressin secretion.
- 5 Recent evidence shows that centrally administered AT1 antagonists inhibit dipsogenic, natriuretic, pressor and vasopressin secretory responses to intracerebroventricular infusion of hypertonic saline. This suggests that an angiotensinergic neural pathway has a role in osmoregulatory responses.
- 6 Central angiotensinergic pathways which include neural inputs to the rostral ventrolateral medulla may use AT1 receptors and play a role in the function of sympathetic pathways maintaining arterial pressure.
87.
88.
Studies have shown that N-methyl-d-aspartate (NMDA) receptors play a critical role in pain processing at different levels of the central nervous system. In this study, we used cortex-specific NR1 knockout mice (C57BL/6 strain) to elucidate the role of cortical NMDA receptors in pain processes. On post-natal day 20, paw withdrawal latency (PWL) to a noxious thermal stimulus was measured in male and female knockout (KO), control (Ctrl), and C57BL/6 (C57) mice. Twenty-four hours later, the same mice were tested in the formalin-pain assay (20 μl of 5% formalin injected into one hind-paw). The results show that KO mice (both male and female) have significantly reduced pain responses during both early and late phases of formalin test, as compared with Ctrl and C57 mice (p < 0.01). By contrast, no differences among groups were found in PWL to a noxious thermal stimulus. Taken together, these results demonstrate dissociation in the role of cortical NMDA receptors in mediating different types of pain. 相似文献
89.
90.