全文获取类型
收费全文 | 817篇 |
免费 | 60篇 |
国内免费 | 2篇 |
专业分类
耳鼻咽喉 | 2篇 |
儿科学 | 16篇 |
妇产科学 | 7篇 |
基础医学 | 85篇 |
口腔科学 | 33篇 |
临床医学 | 131篇 |
内科学 | 222篇 |
皮肤病学 | 14篇 |
神经病学 | 49篇 |
特种医学 | 22篇 |
外科学 | 57篇 |
综合类 | 15篇 |
一般理论 | 3篇 |
预防医学 | 101篇 |
眼科学 | 11篇 |
药学 | 73篇 |
中国医学 | 1篇 |
肿瘤学 | 37篇 |
出版年
2023年 | 4篇 |
2022年 | 5篇 |
2021年 | 9篇 |
2020年 | 3篇 |
2019年 | 11篇 |
2018年 | 12篇 |
2017年 | 11篇 |
2016年 | 16篇 |
2015年 | 19篇 |
2014年 | 24篇 |
2013年 | 42篇 |
2012年 | 59篇 |
2011年 | 57篇 |
2010年 | 28篇 |
2009年 | 28篇 |
2008年 | 55篇 |
2007年 | 50篇 |
2006年 | 53篇 |
2005年 | 53篇 |
2004年 | 45篇 |
2003年 | 42篇 |
2002年 | 39篇 |
2001年 | 17篇 |
2000年 | 10篇 |
1999年 | 13篇 |
1998年 | 10篇 |
1997年 | 13篇 |
1996年 | 5篇 |
1995年 | 10篇 |
1994年 | 4篇 |
1993年 | 6篇 |
1992年 | 4篇 |
1991年 | 2篇 |
1990年 | 5篇 |
1989年 | 2篇 |
1988年 | 4篇 |
1987年 | 5篇 |
1981年 | 1篇 |
1977年 | 3篇 |
1976年 | 5篇 |
1974年 | 5篇 |
1973年 | 8篇 |
1972年 | 13篇 |
1971年 | 8篇 |
1970年 | 11篇 |
1969年 | 4篇 |
1968年 | 16篇 |
1967年 | 10篇 |
1966年 | 9篇 |
1965年 | 8篇 |
排序方式: 共有879条查询结果,搜索用时 46 毫秒
1.
2.
Pinocytic rates of macrophages from mice immunized against Toxoplasma gondii and macrophages stimulated to inhibit toxoplasma in vitro. 总被引:2,自引:0,他引:2 下载免费PDF全文
The rate of pinocytosis by macrophages when measured by uptake of horseradish peroxidase was significantly reduced during toxoplasma infection of the cells in vitro when the macrophages were from toxoplasma-immune mice and when control cells were stimulated in vitro to inhibit toxoplasma multiplication. There was, however, no direct correlation between reduced pinocytosis in this model and inhibition or enhancement of toxoplasma multiplication. We conclude that a reduced pinocytic rate is a feature of the unstimulated toxoplasma-immune macrophage, but this change in rate alone does not correlate with the cell's ability to inhibit toxoplasma. In addition, we observed that enhanced pinocytosis as seen in the elicited macrophage was not a requirement for inhibition of toxoplasma multiplication. 相似文献
3.
Wells GD Plyley M Thomas S Goodman L Duffin J 《European journal of applied physiology》2005,94(5-6):527-540
The efficiency of the respiratory system presents significant limitations on the bodys ability to perform exercise due to the effects of the increased work of breathing, respiratory muscle fatigue, and dyspnoea. Respiratory muscle training is an intervention that may be able to address these limitations, but the impact of respiratory muscle training on exercise performance remains controversial. Therefore, in this study we evaluated the effects of a 12-week (10 sessions week–1) concurrent inspiratory and expiratory muscle training (CRMT) program in 34 adolescent competitive swimmers. The CRMT program consisted of 6 weeks during which the experimental group (E, n=17) performed CRMT and the sham group (S, n=17) performed sham CRMT, followed by 6 weeks when the E and S groups performed CRMT of differing intensities. CRMT training resulted in a significant improvement in forced inspiratory volume in 1 s (FIV1.0) (P=0.050) and forced expiratory volume in 1 s (FEV1.0) (P=0.045) in the E group, which exceeded the S groups results. Significant improvements in pulmonary function, breathing power, and chemoreflex ventilation threshold were observed in both groups, and there was a trend toward an improvement in swimming critical speed after 12 weeks of training (P=0.08). We concluded that although swim training results in attenuation of the ventilatory response to hypercapnia and in improvements in pulmonary function and sustainable breathing power, supplemental respiratory muscle training has no additional effect except on dynamic pulmonary function variables. 相似文献
4.
中国狂犬病毒疫苗株(5aG)糖蛋白基因在痘苗病毒中的表达及免疫效果观察 总被引:1,自引:0,他引:1
将克隆到的中国狂犬病毒疫苗株(5aG)的糖蛋白基因重组到痘苗病毒TK区,并在痘苗病毒P11启动子的控制下,构建了狂犬-痘苗重组病毒(VVaG)。经间接免疫荧光和Western免疫印染证明,重组病毒VVaG能良好地表达狂犬病毒糖蛋白,其分子量约为6600。用VVaG免疫小鼠,7d便可诱生较高的狂犬病毒中和抗体,21d达4169,并能100%保护狂犬病毒本毒株和国际标准攻击毒(CVS)的致死量攻击。 相似文献
5.
Isabel Campos-Varela Oscar Len Ares Villagrasa Ester Márquez-Algaba Juliana Esperalba Cristina Dopazo Ibai Los-Arcos Andrés Antón Lluís Castells 《Transplant international》2021,34(10):1908-1913
Solid organ transplant recipients might be at greater risk for acquisition and mortality because of SARS-CoV-2. There are no data regarding SARS-CoV-2 seroprevalence among liver transplant (LT) recipients, and whether it is different from that of the general population or other immunosuppressed groups. We evaluated the prevalence of IgG SARS-CoV-2 antibodies among LT recipients to estimate the frequency of asymptomatic SARS-CoV-2 infection using serological assays in our outpatient clinic. We conducted a cross-sectional analysis from 10 May to 26 October 2020 of all adult (>18 years) LT recipients that underwent a routine laboratory test for the outpatient clinic follow-up at the Hospital Universitari Vall d’Hebron (Barcelona) in which we included serological testing for SARS-CoV-2. Nine out of 294 LT recipients (3.1%) tested positive for anti-SARS-CoV-2 IgG antibodies. Five of them (55.5%) had suffered clinically symptomatic SARS-CoV-2 infection confirmed by RT-PCR, four (44.4%) had presented compatible symptoms but without microbiological confirmation and only one patient (1/9, 11.1%) tested positive without any previous symptom. SARS-CoV-2 seroprevalence among LT recipients in an area highly affected by the pandemic is lower than in the general population in the same area. These results render the possibility of asymptomatic infection in LT recipients very unlikely. 相似文献
6.
目的 探讨特应性皮炎(AD)患儿外周血白细胞介素-17(IL-17)、白细胞介素-8(IL-8)、免疫球蛋白E(IgE)及嗜酸性粒细胞计数(EOS)的水平变化及其意义.方法 选取120例AD患儿作为AD组,以同期30名健康儿童作为对照组,检测并比较两组外周血IL-17、IL-8、IgE及EOS的水平,依据皮损严重程度对AD患儿进行分层分析.结果 AD组患儿的外周血中IL-17、IL-8、IgE及EOS水平均显著高于对照组(P<0.05);AD组患儿的外周血中IL-17、IL-8、IgE、EOS水平及AD严重程度评分各亚组间比较,重度组>中度组>轻度组,且差异具有统计学意义(P<0.05);AD组患儿的外周血中IL-17、IL-8、IgE、EOS水平与AD严重程度评分均呈显著正相关(P<0.05).结论 AD儿童外周血IL-17、IL-8、IgE及EOS水平均显著的增高,且与病情严重程度密切相关. 相似文献
7.
Yano A Tsutsumi S Soga S Lee MJ Trepel J Osada H Neckers L 《Proceedings of the National Academy of Sciences of the United States of America》2008,105(40):15541-15546
Hsp90 inhibitors are being evaluated extensively in patients with advanced cancers. However, the impact of Hsp90 inhibition on signaling pathways in normal tissues and the effect that this may have on the antitumor activity of these molecularly targeted drugs have not been rigorously examined. Breast and prostate carcinomas are among those cancers that respond to Hsp90 inhibitors in animal xenograft models and in early studies in patients. Because these cancers frequently metastasize to bone, it is important to determine the impact of Hsp90 inhibitors in the bone environment. In the current study, we show that, in contrast to its activity against prostate cancer cells in vitro and its inhibition of s.c. prostate cancer xenografts, the Hsp90 inhibitor 17-AAG stimulates the intraosseous growth of PC-3M prostate carcinoma cells. This activity is mediated not by a direct effect on the tumor but by Hsp90-dependent stimulation of osteoclast maturation. Hsp90 inhibition transiently activates osteoclast Src kinase and promotes Src-dependent Akt activation. Both kinases are key drivers of osteoclast maturation, and three agents that block osteoclastogenesis, the Src inhibitor dasatinib, the bisphosphonate alendronate, and the osteoclast-specific apoptosis-inducer reveromycin A, markedly reduced 17-AAG-stimulated tumor growth in bone. These data emphasize the importance of understanding the complex role played by Hsp90 in regulating signal transduction pathways in normal tissues as well as in cancer cells, and they demonstrate that drug-dependent modulation of the local tumor environment may profoundly affect the antitumor efficacy of Hsp90-directed therapy. 相似文献
8.
9.
10.
M V Ronchezel E T Hacbarth C A Len M T Terreri L E Andrade M O Hilário 《Journal of investigational allergology & clinical immunology》2003,13(2):103-107
OBJECTIVES: (1) To study the correlation among conventional clinical and laboratory parameters and the relation between the number of lymphocytes and neutrophils (L/N) in cell suspensions from peripheral blood of patients with juvenile idiopathic arthritis (JIA). (2) To evaluate the L/N relation of JIA patients after an 8 year follow-up period. METHODS: Fifty-one JIA patients (25 female, disease course: 19 systemic, 15 polyarticular, 17 pauciarticular) were enrolled in the study. To measure the L/N relation, we used Boyum's method: The leucocyte separation was done by centrifugation of peripheral blood on Ficoll-Hypaque (FH) gradient, and the number of lymphocytes, monocytes, and neutrophils in 500 cells was determined. The following clinical and laboratory parameters were evaluated: disease activity, number of active and limited joints, functional capacity, erythrocyte sedimentation rate (ESR), and C reactive protein (CRP). Twenty-four healthy children were used as controls. We also studied 13/51 patients from our Pediatric Rheumatology Unit who had been evaluated by the same method 8 years before. RESULTS: We observed the lowest L/N relation in patients with active disease, especially those with polyarticular course. A statistical correlation was also observed with the acute-phase reactants (ESR and CRP, p < 0.05). The majority of patients who had presented a low L/N relation at the first evaluation (8 years before) had a worse outcome. CONCLUSION: The measure of L/N relation from peripheral blood could be used as an auxiliary tool in the assessment of the activity and outcome of JIA patients, especially at disease onset. 相似文献