全文获取类型
收费全文 | 5055篇 |
免费 | 404篇 |
国内免费 | 24篇 |
专业分类
耳鼻咽喉 | 33篇 |
儿科学 | 120篇 |
妇产科学 | 95篇 |
基础医学 | 841篇 |
口腔科学 | 124篇 |
临床医学 | 446篇 |
内科学 | 875篇 |
皮肤病学 | 66篇 |
神经病学 | 898篇 |
特种医学 | 301篇 |
外科学 | 572篇 |
综合类 | 72篇 |
一般理论 | 1篇 |
预防医学 | 363篇 |
眼科学 | 61篇 |
药学 | 378篇 |
中国医学 | 2篇 |
肿瘤学 | 235篇 |
出版年
2021年 | 53篇 |
2018年 | 81篇 |
2017年 | 57篇 |
2016年 | 88篇 |
2015年 | 86篇 |
2014年 | 122篇 |
2013年 | 152篇 |
2012年 | 209篇 |
2011年 | 220篇 |
2010年 | 122篇 |
2009年 | 119篇 |
2008年 | 179篇 |
2007年 | 209篇 |
2006年 | 173篇 |
2005年 | 190篇 |
2004年 | 132篇 |
2003年 | 137篇 |
2002年 | 149篇 |
2001年 | 145篇 |
2000年 | 155篇 |
1999年 | 125篇 |
1998年 | 93篇 |
1997年 | 73篇 |
1996年 | 75篇 |
1995年 | 57篇 |
1994年 | 63篇 |
1993年 | 61篇 |
1992年 | 94篇 |
1991年 | 93篇 |
1990年 | 103篇 |
1989年 | 94篇 |
1988年 | 106篇 |
1987年 | 93篇 |
1986年 | 85篇 |
1985年 | 87篇 |
1984年 | 63篇 |
1983年 | 73篇 |
1982年 | 72篇 |
1981年 | 55篇 |
1980年 | 59篇 |
1979年 | 80篇 |
1978年 | 64篇 |
1977年 | 68篇 |
1976年 | 69篇 |
1975年 | 48篇 |
1974年 | 57篇 |
1973年 | 53篇 |
1972年 | 58篇 |
1971年 | 55篇 |
1968年 | 48篇 |
排序方式: 共有5483条查询结果,搜索用时 15 毫秒
131.
The stress protein BiP is overexpressed and is a major B and T cell target in rheumatoid arthritis 总被引:10,自引:0,他引:10
Bläss S Union A Raymackers J Schumann F Ungethüm U Müller-Steinbach S De Keyser F Engel JM Burmester GR 《Arthritis and rheumatism》2001,44(4):761-771
OBJECTIVE: The ubiquitously expressed intracellular protein formerly designated p68 has been identified as autoantigen at both the antibody and the T cell level in rheumatoid arthritis (RA). METHODS: We used 2 independent approaches, Edman degradation and matrix-assisted laser desorption ionization-time-of-flight mass spectrometry, to characterize p68, and we compared its features with those of the endoplasmic reticulum stress protein BiP. RESULTS: In synovial sections from RA patients, BiP was highly overexpressed as compared with control sections. Under in vitro stress conditions, BiP was found to translocate to the nucleus and the cell surface. BiP-specific autoantibodies were present in 63% of 400 RA patients, in 7% of 200 patients with other rheumatic diseases, and in none of the healthy subjects. Thus, BiP-specific autoantibodies represent a new diagnostic marker in RA. Furthermore, we found that BiP-specific T cell reactivity was altered in RA. In healthy individuals and patients with other rheumatic diseases, BiP-reactive T cells were undetectable. In RA, overt T cell reactivity to BiP was observed or could be induced by specifically blocking antigen presentation to potentially regulatory T cells. CONCLUSION: Since overexpression of BiP has been shown to decrease the sensitivity of cells to killing by cytotoxic T cells, BiP overexpression and BiP-specific autoimmunity may be involved in the pathogenesis of RA. 相似文献
132.
Abbi L. Engel Guan-Cheng Sun Ekram Gad Lauren R. Rastetter Katie Strobe Yi Yang Yushe Dang Mary L. Disis Hailing Lu 《Immunobiology》2013
Protein-bound polysaccharide-K (PSK) is a hot water extract from Trametes versicolor mushroom. It has been used traditionally in Asian countries for its immune stimulating and anti-cancer effects. We have recently found that PSK can activate Toll-like receptor 2 (TLR2). TLR2 is highly expressed on dendritic cells (DC), so the current study was undertaken to evaluate the effect of PSK on DC activation and the potential of using PSK as a vaccine adjuvant. In vitro experiments using mouse bone marrow-derived DC (BMDC) demonstrated that PSK induces DC maturation as shown by dose-dependent increase in the expression of CD80, CD86, MHCII, and CD40. PSK also induces the production of multiple inflammatory cytokines by DC, including IL-12, TNF-α, and IL-6, at both mRNA and protein levels. In vivo experiments using PSK as an adjuvant to OVAp323–339 vaccine showed that PSK as adjuvant leads to enlarged draining lymph nodes with higher number of activated DC. PSK also stimulates proliferation of OVA-specific T cells, and induces T cells that produce multiple cytokines, IFN-γ, IL-2, and TNF-α. Altogether, these results demonstrate the ability of PSK to activate DC in vitro and in vivo and the potential of using PSK as a novel vaccine adjuvant. 相似文献
133.
Sashrika Pillay Adhil Bhagwandin Mads F. Bertelsen Nina Patzke Gerhard Engler Andreas K. Engel Paul R. Manger 《The Journal of comparative neurology》2021,529(1):8-27
Employing cyto‐, myelo‐, and chemoarchitectural staining techniques, we analyzed the structure of the hippocampal formation in the banded mongoose and domestic ferret, species belonging to the two carnivoran superfamilies, which have had independent evolutionary trajectories for the past 55 million years. Our observations indicate that, despite the time since sharing a last common ancestor, these species show extensive similarities. The four major portions of the hippocampal formation (cornu Ammonis, dentate gyrus, subicular complex, and entorhinal cortex) were readily observed, contained the same internal subdivisions, and maintained the topological relationships of these subdivisions that could be considered typically mammalian. In addition, adult hippocampal neurogenesis was observed in both species, occurring at a rate similar to that observed in other mammals. Despite the overall similarities, several differences to each other, and to other mammalian species, were observed. We could not find evidence for the presence of the CA2 and CA4 fields of the cornu Ammonis region. In the banded mongoose the dentate gyrus appears to be comprised of up to seven lamina, through the sublamination of the molecular and granule cell layers, which is not observed in the domestic ferret. In addition, numerous subtle variations in chemoarchitecture between the two species were observed. These differences may contribute to an overall variation in the functionality of the hippocampal formation between the species, and in comparison to other mammalian species. These similarities and variations are important to understanding to what extent phylogenetic affinities and constraints affect potential adaptive evolutionary plasticity of the hippocampal formation. 相似文献
134.
Glocker C. Grohmann R. Engel R. Seifert J. Bleich S. Stübner S. Toto S. Schüle C. 《European archives of psychiatry and clinical neuroscience》2021,271(8):1425-1435
European Archives of Psychiatry and Clinical Neuroscience - Galactorrhea is a well-known adverse drug reaction (ADR) of numerous antipsychotic drugs (APD) and is often distressing for those... 相似文献
135.
Timothy D. Smith Brent A. Craven Serena M. Engel Blaire Van Valkenburgh Valerie B. DeLeon 《Anatomical record (Hoboken, N.J. : 2007)》2021,304(1):127-138
Nasal turbinals, delicate and complex bones of the nasal cavity that support respiratory or olfactory mucosa (OM), are now easily studied using high resolution micro-computed tomography (μ-CT). Standard μ-CT currently lacks the capacity to identify OM or other mucosa types without additional radio-opaque staining techniques. However, even unstained mucosa is more radio-opaque than air, and thus mucosal thickness can be discerned. Here, we assess mucosal thickness of the nasal fossa using the cranium of a cadaveric adult dog that was μ-CT scanned with an isotropic resolution of 30 μm, and subsequently histologically sectioned and stained. After co-alignment of μ-CT slice planes to that of histology, mucosal thickness was estimated at four locations. Results based on either μ-CT or histology indicate olfactory mucosa is thicker on average compared with non-olfactory mucosa (non-OM). In addition, olfactory mucosa has a lesser degree of variability than the non-OM. Variability in the latter appears to relate mostly to the varying degree of vascularity of the lamina propria. Because of this, in structures with both specialized vascular respiratory mucosa and OM, such as the first ethmoturbinal (ET I), the range of thickness of OM and non-OM may overlap. Future work should assess the utility of diffusible iodine-based contrast enhanced CT techniques, which can differentiate epithelium from the lamina propria, to enhance our ability to differentiate mucosa types on more rostral ethmoturbinals. This is especially critical for structures such as ET I, which have mixed functional roles in many mammals. 相似文献
136.
137.
Association of GATA-1 and its cofactor Friend of GATA-1 (FOG-1) is essential for erythroid and megakaryocyte development. To assess functions of GATA-1-FOG-1 association during mouse development, we used the GATA-1 hematopoietic regulatory domain to generate transgenic mouse lines expressing a mutant GATA-1, which contains a substitution of glycine 205 for valine (V205G) that abrogates its association with FOG-1. We examined whether the transgenic expression of mutant GATA-1 rescues GATA-1 germ line mutants from embryonic lethality. In high-expressor lines we observed that the GATA-1(V205G) rescues GATA-1-deficient mice from embryonic lethality at the expected frequency, revealing that excess GATA-1(V205G) can eliminate the lethal anemia that is due to GATA-1 deficiency. In contrast, transgene expression comparable to the endogenous GATA-1 level resulted in much lower frequency of rescue, indicating that the GATA-1-FOG-1 association is critical for normal embryonic hematopoiesis. Rescued mice in these analyses exhibit thrombocytopenia and display dysregulated proliferation and impaired cytoplasmic maturation of megakaryocytes. Although anemia is not observed under steady-state conditions, stress erythropoiesis is attenuated in the rescued mice. Our findings reveal an indispensable role for the association of GATA-1 and FOG-1 during late-stage megakaryopoiesis and provide a unique model for X-linked thrombocytopenia with inherited GATA-1 mutation. 相似文献
138.
139.
140.