全文获取类型
收费全文 | 324篇 |
免费 | 8篇 |
国内免费 | 1篇 |
专业分类
耳鼻咽喉 | 18篇 |
儿科学 | 37篇 |
妇产科学 | 4篇 |
基础医学 | 36篇 |
口腔科学 | 9篇 |
临床医学 | 56篇 |
内科学 | 30篇 |
皮肤病学 | 4篇 |
神经病学 | 6篇 |
特种医学 | 26篇 |
外科学 | 21篇 |
综合类 | 23篇 |
预防医学 | 14篇 |
眼科学 | 1篇 |
药学 | 33篇 |
中国医学 | 7篇 |
肿瘤学 | 8篇 |
出版年
2021年 | 3篇 |
2020年 | 2篇 |
2019年 | 7篇 |
2017年 | 2篇 |
2016年 | 3篇 |
2015年 | 5篇 |
2014年 | 23篇 |
2013年 | 25篇 |
2012年 | 14篇 |
2011年 | 9篇 |
2010年 | 11篇 |
2009年 | 14篇 |
2008年 | 5篇 |
2007年 | 11篇 |
2006年 | 9篇 |
2005年 | 5篇 |
2004年 | 2篇 |
2003年 | 8篇 |
2002年 | 6篇 |
2001年 | 2篇 |
2000年 | 7篇 |
1999年 | 4篇 |
1998年 | 14篇 |
1997年 | 18篇 |
1996年 | 11篇 |
1995年 | 9篇 |
1994年 | 10篇 |
1993年 | 12篇 |
1991年 | 5篇 |
1990年 | 5篇 |
1989年 | 3篇 |
1988年 | 1篇 |
1987年 | 1篇 |
1986年 | 1篇 |
1985年 | 1篇 |
1984年 | 3篇 |
1983年 | 2篇 |
1981年 | 2篇 |
1980年 | 1篇 |
1979年 | 1篇 |
1978年 | 3篇 |
1977年 | 1篇 |
1976年 | 1篇 |
1958年 | 1篇 |
1957年 | 2篇 |
1956年 | 2篇 |
1954年 | 2篇 |
1952年 | 16篇 |
1951年 | 23篇 |
1950年 | 2篇 |
排序方式: 共有333条查询结果,搜索用时 15 毫秒
51.
I. A. Schepetkin N. V. Cherdyntseva E. V. Borunov I. L. Skutina S. A. Naumov 《Journal of cancer research and clinical oncology》1991,117(2):172-174
Summary Production of reactive oxygen species by neutrophils was analysed by a chemiluminometric method in the presence of luminol in ten healthy donors, eight patients with gastric cancer and ten patients with gastric precancer. The neutrophil chemiluminominescence response to recombinant tumour necrosis factor (rTNF) was almost five times lower in the gastric patients when compared with healthy donors and precancer patients. The chemiluminescence response to zymosan was decreased only in the gastric cancer patients with chemiluminescence index activation (C
TNF) <1. The observed changes of neutrophil functions are thought to result in a decrease of neutrophil cytotoxic activity in gastric cancer patients. 相似文献
52.
The binding of the cardiac glycoside, ouabain, to cells had been used to quantify the number of active cation pumps. In this study, lymphocytes were incubated with 3H-ouabain and the equilibrium binding analyzed for the maximal number of specific binding sites. Lymphocytes from normal peripheral blood bound 44,200 +/- 9920 molecules/cell, compared with 29,200 +/- 8370 molecules/cell for the lymphocytes of chronic lymphocytic leukemia (CLL) subjects. This difference was significant (p less than 0.01) and did not reflect a lower number of sites on B cells than T cells, since B-cell-enriched lymphocytes from normal peripheral blood showed the same ouabain binding characteristics as the standard T-cell-rich preparation. Although monocytes bind threefold more ouabain than lymphocytes, the small monocyte contamination (3.0%) in normal lymphocyte preparations could not account for the difference between normal and CLL. The fewer ouabain binding sites on CLL lymphocytes may reflect both their smaller size (by 10%) and lower mitotic activity compared with lymphocytes from normal peripheral blood. 相似文献
53.
Plasma cells induce apoptosis of pre-B cells by interacting with bone marrow stromal cells 总被引:2,自引:0,他引:2
By using two-color phenotypic analysis with fluorescein isothiocyanate- anti-CD38 and phycoerythrin-anti-CD19 antibodies, we found that pre-B cells (CD38+CD19+) signifcantly decreased depending on the number of plasma cells (CD38++CD19+) in the bone marrow (BM) in the cases with BM plasmacytosis, such as myelomas and even polyclonal gammopathy. To clarify how plasma cells suppress survival of pre-B cells, we examined the effect of plasma cells on the survival of pre-B cells with or without BM-derived stromal cells in vitro. Pre-B cells alone rapidly entered apoptosis, but interleukin-7 (IL-7), a BM stromal cell line (KM- 102), or culture supernatants of KM-102 cells could support pre-B cell survival. On the other hand, inhibitory factors such as transforming growth factor-beta1 (TGF-beta1) and macrophage inflammatory protein- 1beta (MIP-1beta) could suppress survival of pre-B cells even in the presence of IL-7. Plasma cells alone could not suppress survival of pre- B cells in the presence of IL-7, but coculture of plasma cells with KM- 102 cells or primary BM stromal cells induced apoptosis of pre-B cells. Supernatants of coculture with KM-102 and myeloma cell lines (KMS-5) also could suppress survival of pre-B cells. Furthermore, we examined the expression of IL-7, TGF-beta1, and MIP-1beta mRNA in KM-102 cells and primary stromal cells cocultured with myeloma cell lines (KMS-5). In these cells, IL-7 mRNA was downregulated, but the expression of TGF- beta1 and MIP-1beta mRNA was augmented. Therefore, these results suggest that BM-derived stromal cells attached to plasma (myeloma) cells were modulated to secrete lesser levels of supporting factor (IL- 7) and higher levels of inhibitory factors (TGF-beta1 and MIP-1beta) for pre-B cell survival, which could explain why the increased number of plasma (myeloma) cells induced suppression of pre-B cells in the BM. This phenomenon may represent a feedback loop between pre-B cells and plasma cells via BM stromal cells in the BM. 相似文献
54.
Nitric oxide and the control of renin secretion 总被引:3,自引:0,他引:3
Summary— Research during recent years has established nitric oxide as a unique signaling molecule that plays important roles in the regulation of the cardiovascular, nervous, renal, immune and other systems. Nitric oxide has also been implicated in the control of the secretion of hormones by the pancreas, hypothalamus, pituitary and other endocrine glands, and evidence is accumulating that it contributes to the regulation of the secretion of renin by the kidneys. The enzyme nitric oxide synthetase is present in vascular and tubular elements of the kidney, particularly in cells of the macula densa , a structure that plays an important role in the control of renin secretion. Guanylyl cyclase, a major target for nitric oxide, is also present in the kidney and is responsive to changes in nitric oxide levels. Drugs that inhibit nitric oxide synthesis generally suppress renin release in vivo and in vitro , suggesting a stimulatory role for the L-arginine-nitric oxide pathway in the control of renin secretion. Under some conditions, however, blockade of nitric oxide synthesis increases renin secretion. Recent studies indicate that nitric oxide not only contributes to the regulation of basal renin secretion, but also participates in the renin secretory responses to activation of the renal baroreceptor, macula densa and beta adrenoceptor mechanisms that regulate renin secretion. Future research should clarify the mechanisms by which nitric oxide regulates the secretion of renin and establish the physiological significance of this regulation. 相似文献
55.
56.
57.
58.
59.
60.
Synthesis and Pharmacological Evaluation of Indole Derivatives as Deaza Analogues of Potent Human Neutrophil Elastase Inhibitors 下载免费PDF全文
Letizia Crocetti Igor A. Schepetkin Giovanna Ciciani Maria Paola Giovannoni Gabriella Guerrini Antonella Iacovone Andrei I. Khlebnikov Liliya N. Kirpotina Mark T. Quinn Claudia Vergelli 《Drug development research》2016,77(6):285-299
Preclinical Research |