全文获取类型
收费全文 | 857篇 |
免费 | 37篇 |
国内免费 | 24篇 |
专业分类
耳鼻咽喉 | 1篇 |
儿科学 | 31篇 |
妇产科学 | 17篇 |
基础医学 | 74篇 |
口腔科学 | 19篇 |
临床医学 | 110篇 |
内科学 | 222篇 |
皮肤病学 | 43篇 |
神经病学 | 60篇 |
特种医学 | 105篇 |
外科学 | 37篇 |
综合类 | 71篇 |
预防医学 | 45篇 |
眼科学 | 20篇 |
药学 | 30篇 |
中国医学 | 1篇 |
肿瘤学 | 32篇 |
出版年
2021年 | 7篇 |
2019年 | 6篇 |
2018年 | 7篇 |
2017年 | 6篇 |
2016年 | 12篇 |
2015年 | 10篇 |
2014年 | 18篇 |
2013年 | 60篇 |
2012年 | 17篇 |
2011年 | 19篇 |
2010年 | 32篇 |
2009年 | 32篇 |
2008年 | 16篇 |
2007年 | 38篇 |
2006年 | 15篇 |
2005年 | 15篇 |
2004年 | 14篇 |
2003年 | 13篇 |
2002年 | 10篇 |
2001年 | 12篇 |
2000年 | 10篇 |
1999年 | 14篇 |
1998年 | 50篇 |
1997年 | 47篇 |
1996年 | 36篇 |
1995年 | 26篇 |
1994年 | 31篇 |
1993年 | 35篇 |
1992年 | 6篇 |
1991年 | 8篇 |
1990年 | 14篇 |
1989年 | 35篇 |
1988年 | 20篇 |
1987年 | 23篇 |
1986年 | 15篇 |
1985年 | 7篇 |
1984年 | 9篇 |
1983年 | 7篇 |
1982年 | 9篇 |
1981年 | 10篇 |
1980年 | 10篇 |
1977年 | 5篇 |
1976年 | 7篇 |
1975年 | 6篇 |
1965年 | 4篇 |
1963年 | 6篇 |
1962年 | 5篇 |
1960年 | 5篇 |
1955年 | 4篇 |
1941年 | 11篇 |
排序方式: 共有918条查询结果,搜索用时 15 毫秒
91.
92.
93.
Rudy W; Guckel B; Siebels M; Lindauer M; Meuer SC; Moebius U 《International immunology》1997,9(6):853-860
Introduction of co-stimulatory molecules like CD80 and CD86 represents a
means to augment the immunogenicity of tumor cells and to induce immune
responses directed at tumor antigens. Here we compared CD80- and
CD86-transfected human melanoma cells to induce primary immune responses by
their capacity to promote proliferation of human allogeneic resting T
lymphocytes. CD80- and CD86-transfected SkMel63 melanoma cells induced T
cell activation to a comparable degree, which was found to be independent
of the cell surface density of these co- stimulatory molecules.
Co-expression of CD80 and CD86 did not result in a synergistic increase in
T cell proliferation. Both CD80 and CD86 transfectants induced the
proliferation of isolated CD4+ or CD8+ T cells. Exogenous IL-2, IL-4 and
tumor necrosis factor-alpha respectively enhanced primary T cell
proliferation independent of CD80 or CD86 expression. Interestingly,
differential activities of CD80 and CD86 were observed following
stimulation of resting T cells in the presence of IL-12. Whereas IL-12
increased T cell proliferation in the presence of CD86-transfected melanoma
cells, it exhibited an inhibitory function in the presence of
CD80-expressing SkMel63 cells. Experimental evidence indicates that this
inhibitory effect was mediated by IFN- gamma since (I) IFN-gamma secretion
of stimulated T cells was augmented by IL-12, (II) exogenous IFN-gamma also
inhibited T cell proliferation induced by CD80- but not CD86-transfected
SkMel63 cells and (III) the inhibitory effect of IL-12 was blocked by an
anti-IFN-gamma mAb.
相似文献
94.
95.
Background
A retrospective assessment of contrast enhanced computed tomography (CECT) scan findings in histopathologically proven cases of carcinoma of the gallbladder (GB) was performed to review its role in diagnosis, staging and assessment of surgical resectability.Methods
All the patients had been subjected to a standardised abdominal helical computed tomography scan. Orally administered iodinated contrast was used for opacification of bowel and dynamic intravenous injection of non-ionic iodinated contrast for studying the lesional enhancement and vascular structures.Results
The presence of focal or diffuse mass lesions in the gallbladder fossa, infiltration of a liver and second part of duodenum were the most reliable diagnostic features in carcinoma gallbladder. Regional spread was better delineated on CT scan as compared with ultrasonography.Conclusion
CT scan is an effective method for evaluating, characterizing and detecting the spread of GB carcinomas.Key Words: Gall Bladder, Carcinoma, Computed Tomography 相似文献96.
97.
Congenital heart lesions involving the right ventricular outflow tract (RVOT) are a common problem in paediatric cardiology. These patients need multiple surgical interventions in the form of valved conduits over a lifetime. Surgical re-valvulation was the standard treatment option until the introduction of percutaneous pulmonary valves over a decade ago. These valves can be used to prolong the lifespan of conduits and reduce the number of re-operations. The Melody® valve (Medtronic, Minneapolis, MN, USA) was introduced as the first dedicated percutaneous pulmonary valve. Percutaneous pulmonary valves can be implanted successfully and have the advantage of short hospitalisations. We describe the first three Melody® valve implantations in Africa. 相似文献
98.
Ezzedine K Cazanave C Pistone T Receveur MC Neau D Ragnaud JM Malvy D 《Travel medicine and infectious disease》2008,6(3):152-154
Chikungunya virus infection is a vector-borne self-limiting disease. Recent outbreaks in the Indian Ocean islands have drawn attention to the condition. Nevertheless, only a few reports of co-infection with other communicable agents have been reported. The case described now is of a traveller returning from India with concomitant documented chikungunya virus infection associated with systemic amoebiasis. This report highlights the multifaceted pathology that can be encountered with tropical infections. 相似文献
99.
Lopez AF; Dyson PG; To LB; Elliott MJ; Milton SE; Russell JA; Juttner CA; Yang YC; Clark SC; Vadas MA 《Blood》1988,72(5):1797-1804
Recombinant human (rh) interleukin-3 (IL-3) stimulated the proliferation and differentiation of erythroid, granulocyte, macrophage, eosinophil (Eo), and mixed colonies as well as megakaryocytes from human bone marrow cells. rh IL-3 was a weaker stimulus than rh granulocyte-macrophage colony-stimulating factor (GM- CSF) for day 14 myeloid cell colonies. At day 7 of incubation, rh IL-3 stimulated a few G, M, and Eo clusters but no colonies. This loss of responsiveness of myeloid cells to rh IL-3 was accentuated with further differentiation of the cells. rh IL-3 stimulated very few or no clones after five-day incubation with enriched promyelocytes and myelocytes, whereas rh GM-CSF was an efficient stimulus. Responsiveness to rh IL-3 was completely lost in postmitotic mature neutrophils. Incubation of these cells with rh IL-3 did not result in enhanced antibody-dependent cell-mediated cytotoxicity (ADCC) of tumor cells or superoxide anion production after stimulation with formyl-methyl-leucyl-phenylalanine (FMLP), although they could be stimulated by rh GM-CSF. In addition, preincubation of neutrophils with different concentrations of rh IL-3 failed to increase or decrease their response to rh GM-CSF. In contrast to neutrophils, mature Eos could be stimulated by rh IL-3 to kill antibody-coated tumor cells. These results show that cells of the neutrophilic myeloid series lose their responsiveness to h IL-3 as they differentiate and suggest that although h IL-3 may be an important therapeutic agent to use for hematopoietic regeneration in vivo, the lack of stimulation of mature neutrophil function makes it an unlikely sole candidate as adjunct therapy for treatment of infectious diseases. 相似文献
100.