全文获取类型
收费全文 | 8077篇 |
免费 | 571篇 |
国内免费 | 52篇 |
专业分类
耳鼻咽喉 | 217篇 |
儿科学 | 151篇 |
妇产科学 | 315篇 |
基础医学 | 1053篇 |
口腔科学 | 148篇 |
临床医学 | 718篇 |
内科学 | 1927篇 |
皮肤病学 | 134篇 |
神经病学 | 715篇 |
特种医学 | 249篇 |
外科学 | 1224篇 |
综合类 | 40篇 |
一般理论 | 5篇 |
预防医学 | 428篇 |
眼科学 | 192篇 |
药学 | 570篇 |
中国医学 | 23篇 |
肿瘤学 | 591篇 |
出版年
2023年 | 53篇 |
2022年 | 127篇 |
2021年 | 321篇 |
2020年 | 135篇 |
2019年 | 200篇 |
2018年 | 256篇 |
2017年 | 207篇 |
2016年 | 207篇 |
2015年 | 236篇 |
2014年 | 315篇 |
2013年 | 435篇 |
2012年 | 616篇 |
2011年 | 604篇 |
2010年 | 344篇 |
2009年 | 290篇 |
2008年 | 481篇 |
2007年 | 485篇 |
2006年 | 475篇 |
2005年 | 468篇 |
2004年 | 409篇 |
2003年 | 346篇 |
2002年 | 290篇 |
2001年 | 135篇 |
2000年 | 119篇 |
1999年 | 99篇 |
1998年 | 64篇 |
1997年 | 44篇 |
1996年 | 47篇 |
1995年 | 45篇 |
1994年 | 50篇 |
1993年 | 43篇 |
1992年 | 74篇 |
1991年 | 49篇 |
1990年 | 49篇 |
1989年 | 55篇 |
1988年 | 46篇 |
1987年 | 40篇 |
1986年 | 19篇 |
1985年 | 28篇 |
1984年 | 30篇 |
1982年 | 16篇 |
1981年 | 17篇 |
1980年 | 14篇 |
1979年 | 24篇 |
1978年 | 21篇 |
1976年 | 16篇 |
1974年 | 15篇 |
1971年 | 17篇 |
1969年 | 17篇 |
1967年 | 14篇 |
排序方式: 共有8700条查询结果,搜索用时 15 毫秒
41.
42.
J J Moulin J M Mur P Wild A Demonchy E Eloy A Jeannot 《Revue d'épidémiologie et de santé publique》1988,36(2):99-107
A mortality study was carried out, throughout the period 1970-1984, in a cohort of 963 men who had worked for at least one year in a coal tar distillery. The observed number of deaths, 109, did not significantly differ from the expected number. Using the death rates of the local population as a reference, no excess was observed for lung cancer and for cancers of the larynx, while there was an excess for cancers of the oesophagus but non significant and for cancers of the buccal cavity and pharynx (SMR = 2.17 - p less than 0.05). A nested case-control study was carried out. From within the cohort, 5 deaths from lung cancer and 10 deaths from cancers of the buccal cavity and pharynx were defined as "cases". For each case, all the available dead controls with the same sex, year of birth, tobacco and alcohol consumption were selected from within the cohort. The odds ratios for lung cancer did not reveal any occupational risk. With regard to buccal cavity and pharyngeal cancers, the odds ratios were neither significant for a duration of exposure greater than or equal to 1 year nor for a duration greater than or equal to 5 years along with a latent period greater than or equal to 10 years. Nevertheless there is a significant OR for exposure less than or equal to 10 years (OR = 7.56) but it is near one for exposures greater than 10 years. 相似文献
43.
44.
Survey of the Distribution of a Newly Characterized Receptor for Advanced Glycation End Products in Tissues 总被引:33,自引:2,他引:33
下载免费PDF全文
![点击此处可从《The American journal of pathology》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Jerold Brett Ann Marie Schmidt Shi Du Yan Yu Shan Zou Elliott Weidman David Pinsky Roman Nowygrod Michael Neeper Craig Przysiecki Alan Shaw Antonio Migheli David Stern 《The American journal of pathology》1993,143(6):1699-1712
Advanced glycation end products (AGEs), the final products of nonenzymatic glycation and oxidation of proteins, are found in the plasma and accumulate in the tissues during aging and at an accelerated rate in diabetes. A novel integral membrane protein, termed receptor for AGE (RAGE), forms a central part of the cell surface binding site for AGEs. Using monospecific, polyclonal antibody raised to human recombinant and bovine RAGE, immunostaining of bovine tissues showed RAGE in the vasculature, endothelium, and smooth muscle cells and in mononuclear cells in the tissues. Consistent with these data, RAGE antigen and mRNA were identified in cultured bovine endothelium, vascular smooth muscle, and monocyte-derived macrophages. RAGE antigen was also visualized in bovine cardiac myocytes as well as in cultures of neonatal rat cardiac myocytes and in neural tissue where motor neurons, peripheral nerves, and a population of cortical neurons were positive. In situ hybridization confirmed the presence of RAGE mRNA in the tissues, and studies with rat PC12 pheochromocytes indicated that they provide a neuronal-related cell culture model for examining RAGE expression. Pathological studies of human atherosclerotic plaques showed infiltration of RAGE-expressing cells in the expanded intima. These results indicate that RAGE is present in multiple tissues and suggest the potential relevance of AGE-RAGE interactions for modulating properties of the vasculature as well as neural and cardiac function, prominent areas of involvement in diabetes and in the normal aging process. 相似文献
45.
Five modern bicycle helmets were studied to elucidate some of the variations in ventilation performance, using both a heated manikin headform and human subjects (n=7). Wind speed and head angle were varied to test their influence on the measured steady-state heat exchange (cooling power) in the skull section of the headform. The cooling power transmitted by the helmets varied from about 60% to over 90% of that of the nude headform, illustrating the range of present manufacturer designs. Angling the head forward by 30° was found to provide better cooling power to the skull (up to 25%) for three of the helmets and almost equal cooling power in the remaining two cases. Comparisons of skull ventilation at these angles with human subjects strongly supported the headform results. 相似文献
46.
47.
Jastrzebska M Wrzalik R Kocot A Zalewska-Rejdak J Cwalina B 《Journal of biomaterials science. Polymer edition》2003,14(2):185-197
For the first time, Raman spectroscopy has been employed to investigate formation of cross-links in collagen and porcine pericardium tissue upon glutaraldehyde (GA) treatment. GA treatment causes a very high fluorescence background, which overlaps Raman bands. It has been found that short fixation time, i.e. 2 h, reduces background radiation significantly, providing new possibilities for studying changes in molecular structure of collagen upon GA modification. The observed changes in position and intensity of Raman bands allowed us to recognize different types of GA-collagen interactions. Strong spectral evidence has been found for the peptide contribution to the formation of the GA-collagen cross-links and for the formation of secondary amines via Schiff base intermediates, and pyridinium-type cross-links. The results also revealed that different hydration levels and a more complex structure of intact tissue in comparison to collagen preparation strongly influence the formation of a GA cross-linking network, e.g. ether-type bond is preferred to form in a less hydrated collagen preparation. Our results have shown that GA treatment causes an increase in water content of pericardium tissue and collagen. 相似文献
48.
Incidence and identification of Klebsiella planticola in clinical isolates with emphasis on newborns
Studies conducted in France and Germany suggest that up to 19% of clinically identified Klebsiella sp. are actually Klebsiella planticola, an environmental species that has been attributed to two cases of septicemia, with a rare isolate of Klebsiella terrigena (0. 4%) being identified. A 1-year survey of newborns on a neonatal ward, also conducted in Germany, reported that 72% of Klebsiella sp. were Klebsiella oxytoca and 8.7% were K. planticola. The tests necessary to identify these species are not found in most clinical identification schemes or in the database matrices of most commercial identification products. To determine the incidence of unrecognized K. planticola among the Klebsiella sp. isolates in our collection, we used the battery of seven supplemental tests amended from the work of Monnet and Freney to test 352 stock isolates and 84 fresh clinical isolates from four local hospitals. After testing 436 strains of Klebsiella, only one strain was identified as a possible K. planticola and none was identified as K. terrigena. We tested an additional 43 stock strains of K. oxytoca isolated from newborns by using eight biochemical tests and found one additional strain of K. planticola. The occurrence of K. planticola in our collection is far less frequent than that observed in other countries. 相似文献
49.
Bone marrow-derived mesenchymal stem cells in repair of the injured lung 总被引:26,自引:0,他引:26
Rojas M Xu J Woods CR Mora AL Spears W Roman J Brigham KL 《American journal of respiratory cell and molecular biology》2005,33(2):145-152
We sought to determine whether an intact bone marrow is essential to lung repair following bleomycin-induced lung injury in mice, and the mechanisms of any protective effects conferred by bone marrow-derived mesenchymal stem cell (BMDMSC) transfer. We found that myelosupression increased susceptibility to bleomycin injury and that BMDMSC transfer was protective. Protection was associated with the differentiation of engrafted BMDMSC into specific and distinct lung cell phenotypes, with an increase in circulating levels of G-CSF and GM-CSF (known for their ability to promote the mobilization of endogenous stem cells) and with a decrease in inflammatory cytokines. In vitro, cells from injured, but not from normal, mouse lung produced soluble factors that caused BMDMSC to proliferate and migrate toward the injured lung. We conclude that bone marrow stem cells are important in the repair of bleomycin-injured lung and that transfer of mesenchymal stem cells protects against the injury. BMDMSC localize to the injured lung and assume lung cell phenotypes, but protection from injury and fibrosis also involves suppression of inflammation and triggering production of reparative growth factors. 相似文献
50.
Rus V Zernetkina V Puliaev R Cudrici C Mathai S Via CS 《Clinical immunology (Orlando, Fla.)》2005,117(1):48-56
Increased expression of TRAIL in membrane-bound and soluble form in patients with systemic lupus erythematosus (SLE) has been previously reported. In this study, we characterized the upregulation of T-cell-associated and soluble TRAIL (sTRAIL) in vivo and the modulation of TRAIL expression and soluble protein release in vitro following T cell activation and IFNalpha exposure. The expression of membrane-bound TRAIL as determined by flow cytometry was higher on CD4(+) and CD8(+) T cells from lupus patients compared to controls, particularly on activated CD69(+)CD8(+) T cells. Similarly, sTRAIL levels determined by ELISA were significantly elevated in serum from patients with active SLE and correlated with levels of IFNalpha. In vitro, both T-cell-associated and sTRAIL were maximally induced by T cell activation plus IFNalpha in patients and controls. By Western blot analysis, sTRAIL was detected in sera in both the monomeric and multimeric, functional form. Both forms of TRAIL were functional in vitro as determined by Annexin V staining and (51)Cr release assay but the apoptotic activity of membrane TRAIL was 2.5-fold higher compared to that of sTRAIL. These results indicate that IFNalpha-induced enhancement of TRAIL expression and of TRAIL-mediated apoptosis may amplify the abnormal apoptotic process in SLE. 相似文献