全文获取类型
收费全文 | 1205篇 |
免费 | 114篇 |
国内免费 | 5篇 |
专业分类
耳鼻咽喉 | 34篇 |
儿科学 | 65篇 |
妇产科学 | 35篇 |
基础医学 | 141篇 |
口腔科学 | 11篇 |
临床医学 | 162篇 |
内科学 | 201篇 |
皮肤病学 | 72篇 |
神经病学 | 99篇 |
特种医学 | 21篇 |
外科学 | 127篇 |
综合类 | 15篇 |
现状与发展 | 1篇 |
一般理论 | 1篇 |
预防医学 | 179篇 |
眼科学 | 17篇 |
药学 | 66篇 |
肿瘤学 | 77篇 |
出版年
2023年 | 17篇 |
2022年 | 15篇 |
2021年 | 37篇 |
2020年 | 36篇 |
2019年 | 50篇 |
2018年 | 47篇 |
2017年 | 49篇 |
2016年 | 29篇 |
2015年 | 39篇 |
2014年 | 49篇 |
2013年 | 87篇 |
2012年 | 96篇 |
2011年 | 97篇 |
2010年 | 45篇 |
2009年 | 35篇 |
2008年 | 65篇 |
2007年 | 66篇 |
2006年 | 47篇 |
2005年 | 54篇 |
2004年 | 53篇 |
2003年 | 40篇 |
2002年 | 47篇 |
2001年 | 13篇 |
2000年 | 22篇 |
1999年 | 12篇 |
1998年 | 12篇 |
1997年 | 5篇 |
1996年 | 9篇 |
1995年 | 7篇 |
1994年 | 11篇 |
1993年 | 4篇 |
1992年 | 15篇 |
1991年 | 9篇 |
1990年 | 7篇 |
1989年 | 6篇 |
1988年 | 9篇 |
1987年 | 14篇 |
1986年 | 5篇 |
1985年 | 2篇 |
1984年 | 7篇 |
1983年 | 6篇 |
1982年 | 6篇 |
1981年 | 5篇 |
1978年 | 5篇 |
1974年 | 4篇 |
1973年 | 6篇 |
1972年 | 7篇 |
1971年 | 5篇 |
1908年 | 1篇 |
1881年 | 1篇 |
排序方式: 共有1324条查询结果,搜索用时 31 毫秒
1.
2.
Nikki Lee 《Journal of human lactation》2006,22(1):11; author reply 11-11; author reply 12
3.
Lungiswa L Nkonki Tanya M Doherty Zelee Hill Mickey Chopra Nikki Schaay Carl Kendall 《AIDS research and therapy》2007,4(1):27
Background
The objective of this study was to examine missed opportunities for participation in a prevention of mother-to-child transmission (PMTCT) programme in three sites in South Africa. A rapid anthropological assessment was used to collect in-depth data from 58 HIV-positive women who were enrolled in a larger cohort study to assess mother-to-child HIV transmission. Semi-structured interviews were conducted with the women in order to gain an understanding of their experiences of antenatal care and to identify missed opportunities for participation in PMTCT. 相似文献4.
Qualitative Data Analysis: An Introduction 总被引:1,自引:1,他引:0
5.
Periocular anaesthesia: technique, effectiveness and complications with special reference to postoperative ptosis 总被引:3,自引:0,他引:3
The effectiveness of periocular anaesthesia and its complications were examined in 100 successive cataract operations. The patients were divided into 3 groups according to the duration of ocular compression with an Autopressor device after administration of periocular anaesthesia. In the control group, no compression was used (C-O, n = 36 patients). In the other two groups, compression was used for 10 (C-10, n = 32) and for 20 (C-20, n = 32) min. No differences in globe or orbicular akinesia were found between the groups. At 10 min, immobilisation of the globe in different directions was attained in 60.1-84.5% of the patients. Compression for an additional 10 min did not significantly improve the akinesia. In contrast, the hitherto undescribed loss of light perception increased with time: 15 patients at 10 min and 22 at 20 min were unable to see light. Chemosis and haematomas in the upper eyelid occurred more often in C-0 than in the other 2 groups. One day postoperatively the average palpebral aperture was smaller in C-0 than in the other two groups. The frequent postoperative ptosis (74.3% on the 1st day) decreased rapidly, but on postoperative day 7, 9 patients still had ptosis. In only one patient was ptosis still recognizable at 6 weeks postoperatively. No serious complications occurred. This study demonstrates that periocular anaesthesia with ocular compression is a suitable method for cataract surgery. 相似文献
6.
7.
We determined, in monkeys, whether halothane-induced cerebrovascular dilation is mediated by beta-adrenergic receptors and whether cerebrovascular tone progressively returns to baseline values during prolonged halothane anesthesia. Total cerebral blood flow (CBF), cerebral perfusion pressure, plasma halothane concentration, and arterial blood gas tensions and pH were measured in 14 rhesus monkeys mechanically ventilated with 0.5% (inspired) halothane, 33% O2 and balance N2O. Halothane was increased to 2.0% and the measurements repeated 30 and 60 min later. Then either 0.9% NaCl (controls n = 6) or propranolol (n = 8), 1.0 mg/kg was infused intravenously over 10 min, and the measurements repeated at 70, 90, 120, and 150 min. After 30 min at 2.0% halothane, CBF increased in the controls by 50% (P less than 0.05) from 92 +/- 8 (mean +/- SD) to 137 +/- 39 ml X 100 g-1 X min-1 and in the propranolol group by 30% (P less than 0.05) from 106 +/- 33 to 137 +/- 28 ml X 100 g-1 X min-1. After 2.5 hr of 2.0% halothane anesthesia, CBF remained elevated above baseline levels, but by only 28 and 23% in the control and propranolol groups, respectively. Cerebrovascular resistance was identical in both groups (0.55 +/- 0.33 vs 0.53 +/- 0.13 mm Hg X ml-1 X 100 g 1 X min 1). The results show that there is only a 10-20% return of CBF toward baseline levels after up to 2.5 hr of 2% halothane anesthesia. The results also indicate that halothane-induced cerebrovascular dilation is not mediated by beta-adrenergic receptors. 相似文献
8.
J A Cotterill 《British journal of hospital medicine》1992,47(2):115-119
Deceit by patients is fortunately relatively uncommon. Artefact dermatitis, especially in females, may form only part of a large spectrum of a simulated disease, while in males the patient may have financial compensation in mind. 相似文献
9.
Salcedo M Colucci F Dyson PJ Cotterill LA Lemonnier FA Kourilsky P Di Santo JP Ljunggren HG Abastado JP 《European journal of immunology》2000,30(4):1094-1101
NK cells acquire the ability to recognize MHC class I molecules during development. Studies with Qa-1(b) tetramers (Qa-1 tetramers) showed that nearly all NK1.1(+) cells from newborn C57BL/6 mice express Qa-1-binding receptors. Cytotoxic activity of these cells is fully inhibited by Qa-1 ligands on target cells. In contrast, neither receptors for H-2K(b) nor H-2D(b) were observed on NK1.1(+) cells from newborn mice. After birth, frequencies of Qa-1 tetramer(+)/ NK1.1(+) cells gradually decrease as the number of Ly49(+) /NK1.1(+) cells increases. Cell transfer studies showed that Qa-1 tetramer(+) cells from newborn mice do not lose expression of Qa-1 receptors, but that they further acquire expression of Ly49 molecules. Acquisition of Qa-1-binding receptors appears largely independent of host MHC class I molecules, as observed in studies using beta2-microglobulin-deficient (beta2m(-/-)) mice as well as K(b)/ D(b-/-) and K(b)/D(b)/beta2m(-/-) mice. The present results suggest that Qa-1-binding receptors play an important role in the specificity of developing NK cells, and suggest that these cells rely mainly on inhibitory receptors specific for non-classical MHC class I molecules to maintain self tolerance during the first weeks of life. 相似文献
10.
Redirecting the humoral immune response against Streptococcus mutans antigen P1 with monoclonal antibodies
下载免费PDF全文
![点击此处可从《Infection and immunity》网站下载免费的PDF全文](/ch/ext_images/free.gif)
The adhesin P1 of Streptococcus mutans has been studied as an anticaries vaccine antigen. An anti-P1 monoclonal antibody (MAb) bound to S. mutans prior to mucosal immunization of mice was shown previously to alter the amount, specificity, isotype, and biological activity of anti-P1 antibodies. The present study was undertaken to screen this and four additional anti-P1 MAbs for immunomodulatory activity when complexed with S. mutans and administered by a systemic route and to evaluate sera from immunized mice for the ability to inhibit adherence of S. mutans to immobilized human salivary agglutinin. All five MAbs tested influenced murine anti-P1 serum antibody responses in terms of subclass distribution and/or specificity. The effects varied depending on which MAb was used and its coating concentration. Two MAbs promoted a more effective, and two others a less effective, adherence inhibition response. An inverse relationship was observed between the ability of the MAbs themselves to inhibit adherence and the ability of antibodies elicited following immunization with immune complexes to inhibit adherence. Statistically significant correlations were demonstrated between the levels of anti-P1 serum immunoglobulin G2a (IgG2a) and IgG2b, but not of IgG1 or IgG3, and the ability of sera from immunized animals to inhibit bacterial adherence. These results indicate that multiple anti-P1 MAbs can mediate changes in the immune response and that certain alterations are potentially more biologically relevant than others. Immunomodulation by anti-P1 MAbs represents a useful strategy to improve the beneficial immune response against S. mutans. 相似文献