全文获取类型
收费全文 | 1227篇 |
免费 | 98篇 |
国内免费 | 17篇 |
专业分类
耳鼻咽喉 | 10篇 |
儿科学 | 48篇 |
妇产科学 | 53篇 |
基础医学 | 224篇 |
口腔科学 | 54篇 |
临床医学 | 117篇 |
内科学 | 312篇 |
皮肤病学 | 33篇 |
神经病学 | 33篇 |
特种医学 | 100篇 |
外科学 | 99篇 |
综合类 | 37篇 |
预防医学 | 81篇 |
眼科学 | 12篇 |
药学 | 93篇 |
中国医学 | 1篇 |
肿瘤学 | 35篇 |
出版年
2023年 | 7篇 |
2021年 | 10篇 |
2020年 | 11篇 |
2019年 | 10篇 |
2018年 | 21篇 |
2017年 | 16篇 |
2016年 | 31篇 |
2015年 | 18篇 |
2014年 | 21篇 |
2013年 | 41篇 |
2012年 | 49篇 |
2011年 | 43篇 |
2010年 | 39篇 |
2009年 | 46篇 |
2008年 | 38篇 |
2007年 | 62篇 |
2006年 | 47篇 |
2005年 | 50篇 |
2004年 | 46篇 |
2003年 | 28篇 |
2002年 | 33篇 |
2001年 | 28篇 |
2000年 | 34篇 |
1999年 | 22篇 |
1998年 | 26篇 |
1997年 | 45篇 |
1996年 | 40篇 |
1995年 | 20篇 |
1994年 | 23篇 |
1993年 | 25篇 |
1992年 | 12篇 |
1991年 | 31篇 |
1990年 | 18篇 |
1989年 | 28篇 |
1988年 | 32篇 |
1987年 | 26篇 |
1986年 | 26篇 |
1985年 | 26篇 |
1984年 | 19篇 |
1983年 | 19篇 |
1982年 | 10篇 |
1981年 | 16篇 |
1980年 | 14篇 |
1979年 | 12篇 |
1978年 | 13篇 |
1976年 | 7篇 |
1975年 | 9篇 |
1974年 | 8篇 |
1973年 | 16篇 |
1970年 | 9篇 |
排序方式: 共有1342条查询结果,搜索用时 15 毫秒
1.
2.
3.
R T Means N J Olsen S B Krantz E N Dessypris S E Graber W J Stone V L O'Neil T Pincus 《Arthritis and rheumatism》1989,32(5):638-642
Two anemic patients with rheumatoid arthritis were treated with recombinant human erythropoietin (EPO) for 5 months. Both patients showed significant increases in hematocrit, red cell volumes, and marrow erythroid and megakaryocyte progenitor cells. No significant toxic effects from EPO were observed. These data indicate that EPO may be effective in overcoming the pathogenetic factors that limit erythropoiesis in rheumatoid arthritis. 相似文献
4.
The role of growth factors and cytokines in the impaired healing of chronic leg ulcers remains uncertain. The aim of this study was to determine whether changes in the amount and location of cytokines and growth factors may be associated with impaired healing in chronic leg ulcers. Biopsies from leg ulcers of 21 patients and from normal skin of nine healthy volunteers were examined immunohistochemically for selected growth factors and cytokines. Greater staining intensity was found in keratinocytes at the edges of ulcers compared to normal skin, or skin adjacent to the ulcers. Staining at the ulcer edge was more intense in nonhealing ulcers for only vascular endothelial growth factor and platelet-derived growth factor, whereas staining in the adjacent skin was more intense for all factors in the nonhealing phase. For all factors staining was cytoplasmic, suggesting production in these areas. This study shows up-regulation of the production of cytokines and growth factors in keratinocytes of chronic leg ulcers that is greater when the ulcers are nonhealing. 相似文献
5.
6.
7.
Polycythemia vera (PV) is a clonal disease of the hematopoietic stem cell characterized by a hyperplasia of marrow erythropoiesis, granulocytopoiesis, and megakaryocytopoiesis. We previously reported that highly purified PV blood burst-forming units-erythroid (BFU-E) are hypersensitive to recombinant human interleukin-3 (rIL-3). Because these cells may be only a subset, and not representative of marrow progenitors, we have now studied partially purified marrow hematopoietic progenitor cells. Dose-response experiments with PV marrow BFU-E showed a 38-fold increase in sensitivity to rIL-3 and a 4.3-fold increase in sensitivity to recombinant human erythropoietin (rEpo) compared with normal marrow BFU-E. In addition, PV marrow colony-forming units-granulocyte-macrophage (CFU-GM) and CFU-megakaryocyte (CFU-MK) also showed a marked hypersensitivity to rIL-3 and to human recombinant granulocyte-macrophage colony-stimulating factor (rGM-CSF). Dose-response curves with rGM-CSF and blood BFU-E showed a 48-fold increase in sensitivity. No effect of rIL-4, rIL-6, human recombinant granulocyte-CSF (rG-CSF), or macrophage-CSF (rM-CSF) was evident, nor was there any effect of PV cell-conditioned medium on normal BFU-E, when compared with normal cell-conditioned medium. Autoradiography with 125I-rEpo showed an increase in Epo receptors after maturation of PV BFU-E to CFU-E similar to that shown with normal BFU-E, but no increase of specific binding of 125I-rIL-3 by PV CD34+ cells was seen compared with normal CD34+ cells. These studies show that PV marrow hematopoietic progenitor cells are hypersensitive to rIL-3 and rGM-CSF, similar to PV blood BFU-E. While the mechanism does not appear to be due to enhanced binding of rIL-3, the hypersensitivity of PV progenitor cells to IL-3 and GM-CSF may be a key factor in the pathogenesis of PV. 相似文献
8.
9.
Picotamide inhibition of excess in vitro thromboxane B2 release by colorectal mucosa in inflammatory bowel disease. 总被引:1,自引:0,他引:1
Collins CE Benson MJ Burnham WR Rampton DS 《Alimentary pharmacology & therapeutics》1996,10(3):315-320
BACKGROUND: Inflammatory bowel disease is associated with increased mucosal release of eicosanoids. Among these, thromboxane A2 has been proposed as a possible inflammatory mediator; its suppression may be a useful therapeutic option. METHODS: Using a tissue incubation technique, we compared release of immunoreactive thromboxane B2 by colonic biopsies from patients with ulcerative colitis, Crohn's disease and controls, and assessed the inhibitory effect of picotamide, a thromboxane synthesis inhibitor-receptor antagonist, which has been widely used in Italy for management of ischaemic heart and cerebrovascular disease. RESULTS: Increased amounts of thromboxane B2 were released from biopsies from patients with active ulcerative colitis (median 238 pg/20 min/mg wet weight (interquartile range 147- 325), n = 12) and active Crohn's disease (252 (174-450), 6) compared with those from patients with quiescent ulcerative colitis (95 (61- 140), 12) or Crohn's disease (105 (57-201), 13), or controls (136 (64- 206), 8). Incubation with picotamide at concentrations between 100 microM and 1 mM reduced thromboxane B2 release (IC50 890 microM). CONCLUSION: Since increased thromboxane A2 production may have pathogenetic importance, thromboxane synthesis inhibitor-receptor antagonists such as picotamide merit therapeutic trial in the management of inflammatory bowel disease. 相似文献
10.
Anderson RA; Evans LW; Irvine DS; McIntyre MA; Groome NP; Riley SC 《Human reproduction (Oxford, England)》1998,13(12):3319-3325
Follistatin is a binding protein for the activin and inhibin family of
hormones, regulating their biological activity. In the male reproductive
tract, the interaction of these factors is likely to be involved in the
regulation of the proliferation of several cell types. We have investigated
the presence of follistatin and activin A in seminal plasma using specific
immunoassays and have localized follistatin and activin/inhibin subunits in
the adult human testis, prostate and seminal vesicle to establish their
likely sources. High concentrations of immunoreactive follistatin were
present in seminal plasma in normal men (mean 97.9 ng/ml; 1.43 ng/ml in
peripheral plasma) and were similar in men with oligo/azoospermia and
following vasectomy. Follistatin immunoreactivity was localized to both
Leydig and Sertoli cells of the testis, and to epithelial cells of the
prostate gland and seminal vesicle, which are likely to be the predominant
sources of the hormone in seminal plasma. Activin A was also present in
seminal plasma in normal men but was undetectable following vasectomy, thus
deriving from the testis. Consistent with this finding, the betaA-subunit
was immunolocalized in Sertoli and Leydig cells but was not present in
seminal vesicle or prostate gland. The functional significance of the high
concentrations of follistatin secreted into seminal plasma by the prostate
gland and/or seminal vesicle is uncertain, but they may regulate the
biological activity of testis-derived activin A and inhibin B.
相似文献