全文获取类型
收费全文 | 1600篇 |
免费 | 211篇 |
国内免费 | 55篇 |
专业分类
耳鼻咽喉 | 8篇 |
儿科学 | 18篇 |
妇产科学 | 12篇 |
基础医学 | 296篇 |
口腔科学 | 30篇 |
临床医学 | 149篇 |
内科学 | 202篇 |
皮肤病学 | 22篇 |
神经病学 | 22篇 |
特种医学 | 85篇 |
外科学 | 322篇 |
综合类 | 333篇 |
预防医学 | 103篇 |
眼科学 | 7篇 |
药学 | 124篇 |
2篇 | |
中国医学 | 74篇 |
肿瘤学 | 57篇 |
出版年
2024年 | 5篇 |
2023年 | 6篇 |
2022年 | 31篇 |
2021年 | 40篇 |
2020年 | 31篇 |
2019年 | 15篇 |
2018年 | 16篇 |
2017年 | 33篇 |
2016年 | 21篇 |
2015年 | 79篇 |
2014年 | 53篇 |
2013年 | 86篇 |
2012年 | 121篇 |
2011年 | 134篇 |
2010年 | 106篇 |
2009年 | 102篇 |
2008年 | 84篇 |
2007年 | 82篇 |
2006年 | 76篇 |
2005年 | 93篇 |
2004年 | 49篇 |
2003年 | 65篇 |
2002年 | 45篇 |
2001年 | 38篇 |
2000年 | 34篇 |
1999年 | 35篇 |
1998年 | 28篇 |
1997年 | 20篇 |
1996年 | 22篇 |
1995年 | 22篇 |
1994年 | 17篇 |
1993年 | 25篇 |
1992年 | 29篇 |
1991年 | 20篇 |
1990年 | 23篇 |
1989年 | 24篇 |
1988年 | 25篇 |
1987年 | 18篇 |
1986年 | 15篇 |
1985年 | 13篇 |
1984年 | 15篇 |
1983年 | 13篇 |
1982年 | 10篇 |
1981年 | 9篇 |
1980年 | 12篇 |
1979年 | 4篇 |
1978年 | 3篇 |
1977年 | 4篇 |
1976年 | 8篇 |
1975年 | 3篇 |
排序方式: 共有1866条查询结果,搜索用时 15 毫秒
1.
目的 建立蒙药绿松石的质量标准。方法 收集不同产地绿松石,共10批。观察绿松石样品和粉末的性状并进行理化鉴别;按2020年版《中国药典》(四部)通则方法测定绿松石样品中水分、浸出物含量;采用原子吸收光谱法测定绿松石样品铜元素含量。结果 绿松石为不规则、周围带有黑石的块状物,表面蓝绿色,体重,质硬脆,难砸碎,断面呈贝壳状,蜡样光泽,粉末呈灰绿色,无臭,味淡;理化鉴别结果显示,呈铜盐反应;10批次样品中水分含量为0.41%-3.94%(SD=1.37%),浸出物含量为0.21%-0.81%(SD=0.21%),铜元素含量为3.03%-4.63%(SD=0.63%)。结论 初步拟定绿松石中水分含量不得超多5.0%、浸出物含量不得低于0.10%,铜元素含量应为2.60%-4.84%,制定的标准可用于蒙药材绿松石的质量控制。 相似文献
2.
目的 观察优克龙 (Urocalun )治疗输尿管结石的疗效和安全性。 方法 对 6 0例输尿管结石直径 <1cm的患者予口服优克龙治疗 ,4 5 0mg/次 ,3次 /d ,服药 5周。 结果 6 0例患者中结石排出 4 5例 (75 % ) ;10例 (17% )结石位置下降 ;5例 (8% )位置无变化。 4例患者服药后有轻度胃部不适、恶心或口干。 结论 优克龙治疗输尿管结石效果良好。 相似文献
3.
目的 通过彩色多普勒超声心动图 (CDUCG)和核磁共振成像 (MRI)诊断主动脉夹层动脉瘤 (AD)的影像学特征 ,比较两种无创检查技术诊断AD的临床价值。方法 对临床疑诊AD的患者行CDUCG心脏各切面探查 ,重点扫查并测量主动脉各节段异常超声征象 (夹层发生部位、内膜片跨度、管径宽度等 ) ,对相同患者行MRI检查时在扫描图像上辨认并确定夹层发生的部位、撕裂范围等。结果 CDUCG诊断Ⅰ型AD 4例 ,Ⅱ型 2例 ,Ⅲ型AD 1例。MRI对Ⅰ、Ⅱ、Ⅲ型AD均可明确诊断。本文 3例Ⅲ型AD经MRI确诊并检出附壁血栓 2例 ,1例Ⅰ型AD可疑 ,余结果同CDUCG。结论 两种技术诊断AD各有优缺点 ,CDUCG偏重于诊断Ⅰ、Ⅱ型 ,MRI适合各型AD的诊断。前者更为迅速、直观 ,重复性强 ,可了解心血管病变的全部信息 ;危急重症患者不宜或难以接受MRI检查。 相似文献
4.
Bayrak S; Holmdahl R; Travers P; Lauster R; Hesse M; Dolling R; Mitchison NA 《International immunology》1997,9(11):1687-1699
Type II collagen (CII) is of immunological interest because of its
repetitive structure and properties as an autoantigen. The mouse gene has
recently been cloned, thus enabling T cell-defined epitopes to be
identified. Multiple novel epitopes on mouse CII are here detected in the
autoreactive T cell response. The major response is directed to an epitope
with residues 707-721 located on the CB10 fragment. Some 25 other epitopes
are also recognized, including the autologous homologue of the 256-270
epitope which dominates in the response to foreign collagen. The cells
reactive with mouse collagen peptides were of Th1 type, as judged by
release of IFN-gamma. No significant reactivity was detected to mouse CII
peptides during ongoing disease. Alignment of the mouse epitopes revealed a
sequence motif with characteristic side chains at residues P1, P4 and P7,
and to a lesser extent at P5, within a nonamer core sequence. Binding of
these epitopes was simulated in a computer model of the I-Aq molecule,
where peptides with anchor residues at P1, P4 and P7 were indeed found to
fit the binding groove best. The spacing of pockets and the fine structure
of the binding surface of the I-Aq molecule meshes with the repetitive
structure of the collagen (X-Y-Gly), thus providing a likely explanation
for the occurrence of multiple epitopes. Comparison with human DR binding
motifs showed that the I-Aq motif resembles most closely that of the DR4
subtypes which predispose for rheumatoid arthritis.
相似文献
5.
6.
R B Landewé A M Miltenburg F C Breedveld M R Daha B A Dijkmans 《The Journal of rheumatology》1992,19(9):1353-1357
OBJECTIVE: To investigate synergistic interaction between cyclosporine (Cy) and chloroquine (Chl) in an in vitro system, with regard to interferon-gamma (IFN) production by OKT3 activated T cell clones. METHODS. CD4+ and CD8+ T cell clones, derived from synovial tissue of a patient with rheumatoid arthritis (RA) were activated with plastic coated OKT3 monoclonal antibody in the presence or absence of various concentrations of Cy, Chl and their combinations. After 24 h of incubation the supernatants were assayed for IFN by ELISA. RESULTS. Cy as well as Chl were able to completely inhibit in a concentration dependent fashion the IFN production by CD4+ and CD8+ T cell clones. Combinations of Cy and Chl, which in themselves give minor inhibition of IFN production, were able to inhibit in a synergistically enhanced fashion the production of IFN by these clones. The synergy was formally proven by the construction of isoboles. This synergy was most pronounced when drug concentrations were used which individually gave minor inhibition of IFN production. CONCLUSION. We conclude that the results of our in vitro experiments may give rise to further investigation of the promising combination of Cy and Chl in the treatment of RA. 相似文献
7.
8.
Kupffer cell depletion in vivo results in preferential elimination of IgG aggregates and immune complexes via specific Fc receptors on rat liver endothelial cells. 总被引:2,自引:1,他引:1
下载免费PDF全文
![点击此处可从《Clinical and experimental immunology》网站下载免费的PDF全文](/ch/ext_images/free.gif)
W M Bogers R K Stad D J Janssen N van Rooijen L A van Es M R Daha 《Clinical and experimental immunology》1991,86(2):328-333
In the present study we have investigated the clearance kinetics and tissue distribution of monomeric (m) IgG and soluble aggregates of IgG (AIgG) and immune complexes (IC) in normal and Kupffer cell (KC) depleted rats. In normal rats, clearance of mIgG occurred in a biphasic manner with a first half-life (T1/2) (T1) of 36.3 +/- 6.3 min and a second T1/2 (T2) of 168.4 +/- 4.7 min. AIgG composed of 20-27 IgG molecules per aggregate were cleared significantly faster than mIgG with a T1 of 2.5 +/- 0.1 min and a T2 of 32.5 +/- 5.6 min. KC depletion did not have a significant effect on the clearance rate of mIgG (T1: 33.4 +/- 8.9 min; T2; 159.5 +/- 12.5 min), while clearance of AIgG was delayed significantly with T1 4.8 +/- 0.7 min and T2 41.2 +/- 3.2 min. Eight minutes after injection, 77% of AIgG was found in the liver in normal rats while 62% was found in the liver of KC-depleted rats. Double immunofluorescence studies indicated that AIgG in the liver was associated with KC and endothelial cells (EC) in normal rats. In KC-depleted rats, AIgG was strongly associated with EC. A similar staining pattern was observed when IgG-immune IC were administered. The clearance of AIgG in KC-depleted rats was inhibited fully by pre-administration of high concentrations of IgG but not by pretreatment with IgA. asialofetuin (ASFe) or ovalbumin (OVA). Aggregated F(ab')2IgG was cleared with a comparable rate to mIgG from the circulation, again suggesting Fc gamma receptor-mediated elimination of AIgG by EC. There was a reduced degradation of AIgG in rats depleted of KC as compared with normal rats. These data suggest binding and degradation of AIgG by EC in vivo. 相似文献
9.
Endothelial cell lysis induced by lymphokine-activated human peripheral blood mononuclear cells 总被引:5,自引:0,他引:5
A M Miltenburg M E Meijer-Paape M R Daha L C Paul 《European journal of immunology》1987,17(9):1383-1386
In vitro exposure of human peripheral blood mononuclear cells (PBMC) to interleukin 2 results in the generation of lymphokine-activated killer (LAK) cells. Such LAK cells exhibit cytotoxicity against a spectrum of tumor target cell lines whereas they apparently do not affect normal tissues. In this report we show that PBMC that have been activated with T cell growth factor lyse trypsinized human umbilical cord venous endothelial cells as well as endothelial cell monolayers in a dose-dependent manner. Microscopic analysis showed that during the 4-h incubation period cell clumps containing detached endothelial cells and LAK cells were formed. When these clumps were evaluated with trypan blue the endothelial cells stained positive whereas LAK cells excluded the dye. No lysis occurred when fresh PBMC were added to target endothelial cells. The endothelial cell kill could not be blocked with an anti-LFA-1 antibody nor with intact OKT3 or F(ab')2 fragments of WT32. We conclude that lymphokine-activated PBMC exhibit cell-mediated endothelial cell detachment and lysis. 相似文献
10.
D. van Riessen M. R. Daha T. J. M. Smeets F. C. Breedveld 《Rheumatology international》1992,12(1):1-5
Summary It has been suggested that the reduced resistance of patients with rheumatoid arthritis (RA) to bacterial joint infections may be due in part to polymorphonuclear cell (PMN) function. To obtain further insight into the mechanis that contribute to the increased susceptiblity of RA patients to such infections we investigated the influence of different solid surfaces on the ingestion of various bacterial strains by PMN. Both in the presence and absence of serum, phagocytosis of bacteria by PMN was significantly lower on monolayers of synovial fibroblasts as compared to monolayers of endothelial cells and embryonic fibroblasts. It could be shown that the relative influence of the solid surfac on the results of the phagocytosis assay increased when decreasing concentrations of purified IgG were used. The results of this study sugpurified IgG were used. The results of this study suggested that the effect of synovial fibroblasts on PMB may lead to reduced clearance of bacteria from the joint. 相似文献