全文获取类型
收费全文 | 2494篇 |
免费 | 326篇 |
国内免费 | 2篇 |
专业分类
耳鼻咽喉 | 45篇 |
儿科学 | 42篇 |
妇产科学 | 38篇 |
基础医学 | 428篇 |
口腔科学 | 26篇 |
临床医学 | 312篇 |
内科学 | 650篇 |
皮肤病学 | 76篇 |
神经病学 | 221篇 |
特种医学 | 78篇 |
外科学 | 301篇 |
综合类 | 34篇 |
一般理论 | 1篇 |
预防医学 | 164篇 |
眼科学 | 34篇 |
药学 | 149篇 |
肿瘤学 | 223篇 |
出版年
2022年 | 18篇 |
2021年 | 31篇 |
2020年 | 21篇 |
2019年 | 30篇 |
2018年 | 46篇 |
2017年 | 32篇 |
2016年 | 37篇 |
2015年 | 38篇 |
2014年 | 67篇 |
2013年 | 75篇 |
2012年 | 150篇 |
2011年 | 134篇 |
2010年 | 75篇 |
2009年 | 76篇 |
2008年 | 112篇 |
2007年 | 108篇 |
2006年 | 91篇 |
2005年 | 102篇 |
2004年 | 127篇 |
2003年 | 100篇 |
2002年 | 70篇 |
2001年 | 112篇 |
2000年 | 114篇 |
1999年 | 76篇 |
1998年 | 52篇 |
1997年 | 30篇 |
1996年 | 35篇 |
1995年 | 26篇 |
1994年 | 33篇 |
1993年 | 29篇 |
1992年 | 55篇 |
1991年 | 50篇 |
1990年 | 48篇 |
1989年 | 34篇 |
1988年 | 41篇 |
1987年 | 49篇 |
1986年 | 35篇 |
1985年 | 36篇 |
1984年 | 38篇 |
1983年 | 32篇 |
1982年 | 26篇 |
1981年 | 23篇 |
1980年 | 18篇 |
1979年 | 31篇 |
1978年 | 24篇 |
1977年 | 22篇 |
1973年 | 15篇 |
1968年 | 21篇 |
1967年 | 17篇 |
1966年 | 18篇 |
排序方式: 共有2822条查询结果,搜索用时 15 毫秒
71.
O’Grady Aiden Welsh Luke Gibson Matthew Briggs James Speirs Archie Little Mark 《Cardiovascular and interventional radiology》2022,45(1):80-90
CardioVascular and Interventional Radiology - Genicular artery embolisation (GAE) is a novel treatment for patients with knee osteoarthritis (OA). Cadaveric dissection was undertaken to provide a... 相似文献
72.
73.
Direct binding of antithymoctye globulin to haemopoietic progenitor cells in aplastic anaemia 总被引:1,自引:0,他引:1
Flynn J Cox CV Rizzo S Foukaneli T Rice K Murphy M Welsh J Rutherford TR Gordon-Smith EC Gibson FM 《British journal of haematology》2003,122(2):289-297
Antithymocyte globulin (ATG) is widely used in the treatment of aplastic anaemia (AA) and a response occurs in 60-80% of patients. However, its exact mechanism of action in the treatment of AA has yet to be determined. Previously, we have shown that ATG increases colony growth from purified bone marrow CD34+ cells of AA patients in vitro, and decreases stem cell apoptosis and the expression of soluble Fas receptor after ATG therapy in vivo. The aim of this study was to further examine the association of ATG with AA haemopoietic progenitor cells. We describe here that ATG bound directly to CD34+ cells. Forty-six patients and 20 normal control subjects were studied. ATG bound to CD34+ cells in normal control subjects (mean 90.38%) as determined by flow cytometry. The mean percentage of CD34+ cells binding to ATG was 59.90% in untreated aplastic patients, 83.24% in partial responders, 58.3% in non-responders and 62.73% in relapsed patients. In completely recovered patients, ATG binding was indistinguishable from control subjects. The functionality of AA patients' haemopoietic progenitor cells was assessed using colony assays. These results demonstrate the direct binding of ATG to CD34+ cells and suggest that differences in its binding to AA CD34+ cells could reflect functional differences in the haemopoietic stem cell compartment throughout the disease process. 相似文献
74.
John S. Wilson PhD Annette L. Ermshar Robert K. Welsh 《Attachment & human development》2013,15(2):139-157
Abstract Stalking encompasses a wide range of behavioral patterns, risk factors, interpersonal dynamics, and dangerousness. To account for these diverse phenomena, we propose that stalking behavior is best conceptualized by a dynamic interaction of attachment styles and psychodynamic phenomena. This paper articulates a model that explains stalking behavior within the framework of attachment theory. Four prototypical configurations of stalkers and their victims are developed. Each configuration is discussed in terms of a pattern of internal representations, affective constellations, combinations of aggression and narcissism, and potential for future violence. The four configurations proposed here are maintained through stalkers' over ideational linkage fantasies and projective identifications, which range from shame-prone and needy idealization to malevolent torment of the victim. Our model arrays erotomanic, jealous, and persecutory attachments along a continuum of increasingly paranoid and pathological identifications. We argue that these prototypical attachment configurations provide a theoretically driven means of differentiating phases of stalking, and as such provide useful leads in the empirical study and clinical assessment, treatment, and management of stalkers. 相似文献
75.
Heteromultimers of DEG/ENaC subunits form H+-gated channels in mouse sensory neurons 总被引:2,自引:0,他引:2 下载免费PDF全文
Benson CJ Xie J Wemmie JA Price MP Henss JM Welsh MJ Snyder PM 《Proceedings of the National Academy of Sciences of the United States of America》2002,99(4):2338-2343
Acidic extracellular solution activates transient H(+)-gated currents in dorsal root ganglion (DRG) neurons. The biophysical properties of three degenerin/epithelial sodium (DEG/ENaC) channel subunits (BNC1, ASIC, and DRASIC), and their expression in DRG, suggest that they might underlie these H(+)-gated currents and function as sensory transducers. However, it is uncertain which of these DEG/ENaC subunits generate the currents, and whether they function as homomultimers or heteromultimers. We found that the biophysical properties of transient H(+)-gated currents from medium to large mouse DRG neurons differed from BNC1, ASIC, or DRASIC expressed individually, but were reproduced by coexpression of the subunits together. To test the contribution of each subunit, we studied DRG from three strains of mice, each bearing a targeted disruption of BNC1, ASIC, or DRASIC. Deletion of any one subunit did not abolish H(+)-gated currents, but altered currents in a manner consistent with heteromultimerization of the two remaining subunits. These data indicate that combinations of two or more DEG/ENaC subunits coassemble as heteromultimers to generate transient H(+)-gated currents in mouse DRG neurons. 相似文献
76.
Intracellular calcium regulates basolateral potassium channels in a chloride-secreting epithelium. 总被引:5,自引:0,他引:5 下载免费PDF全文
M J Welsh J D McCann 《Proceedings of the National Academy of Sciences of the United States of America》1985,82(24):8823-8826
The two individual cell membranes of epithelia are functionally coupled, so that changes in apical membrane conductance are paralleled by changes in basolateral K+ conductance. However, the signal that regulates basolateral K+ conductance, thereby coupling the two membranes, is unknown. We tested the hypothesis that the cellular calcium concentration, [Ca2+]c, may regulate basolateral K+ conductance in canine tracheal epithelium, a Cl- -secreting epithelium that shows marked membrane coupling. Three findings support the hypothesis. First, the intracellular Ca2+ antagonist 8-(diethylamino)octyl 3,4,5-trimethoxybenzoate hydrochloride (TMB-8) attenuated the secretory response. Second, the secretagogue epinephrine increased [Ca2+]c, as measured with quin-2. Third, we found a K+ channel that was activated by Ca2+ on the cytosolic side of the membrane. Thus, cytosolic Ca2+ regulates the basolateral K+ conductance and may be the signal responsible for functional coupling of the two cell membranes. 相似文献
77.
M P Anderson M J Welsh 《Proceedings of the National Academy of Sciences of the United States of America》1990,87(18):7334-7338
Apical membrane Cl- channels control the rate of transepithelial Cl- secretion in airway epithelia. cAMP-dependent protein kinase and protein kinase C regulate Cl- channels by phosphorylation; in cystic fibrosis cells, phosphorylation-dependent activation of Cl- channels is defective. Another important signaling system involves arachidonic acid, which is released from cell membranes during receptor-mediated stimulation. Here we report that arachidonic acid reversibly inhibited apical membrane Cl- channels in cell-free patches of membrane. Arachidonic acid itself inhibited the channel and not a cyclooxygenase or lipoxygenase metabolite because (i) inhibitors of these enzymes did not block the response, (ii) fatty acids that are not substrates for the enzymes had the same effect as arachidonic acid, and (iii) metabolites of arachidonic acid did not inhibit the channel. Inhibition occurred only when fatty acids were added to the cytosolic surface of the membrane patch. Unsaturated fatty acids were more potent than saturated fatty acids. Arachidonic acid inhibited Cl- channels from both normal and cystic fibrosis cells. These results suggest that fatty acids directly inhibit apical membrane Cl- channels in airway epithelial cells. 相似文献
78.
Gelder CM Hart KW Williams OM Lyons E Welsh KI Campbell IA Marshall SE 《The Journal of infectious diseases》2000,181(6):2099-2102
Polymerase chain reaction using sequence-specific primers was utilized to ascertain the prevalence of 3 polymorphisms of the vitamin D receptor (VDR) gene (FokI F/f, ApaI A/a, and TaqI T/t) in 56 patients with Mycobacterium malmoense pulmonary disease. When compared with 101 controls, M. malmoense patients displayed an increased prevalence of Apa1 A (P=.03; Fisher's exact test), TaqI t (P=.04), and the At VDR haplotype (P=.04), and they displayed a decreased prevalence of FokI f (P=.04). Only 4 (7%) of 56 patients (vs. 29 [28%] of 101 controls) were both positive for FokI f and negative for At (P=.001). This indicates that polymorphisms in the VDR (or in closely linked genes) modulate the susceptibility to M. malmoense and that susceptibility involves multiple genetic and environmental factors. 相似文献
79.
Fc gamma receptor II (CD32) on malignant B cells influences modulation induced by anti-CD19 monoclonal antibody 总被引:1,自引:1,他引:1
Vervoordeldonk SF; Merle PA; van Leeuwen EF; van der Schoot CE; von dem Borne AE; Slaper-Cortenbach IC 《Blood》1994,83(6):1632-1639
Antigenic modulation is one of many factors determining the effectiveness of monoclonal antibody (MoAb)-mediated therapy. To select the isotype of a CD19 MoAb most suitable for radioimmunotherapy of patients with B-cell malignancies, we studied the influence of MoAb isotype on modulation, after binding of the MoAb to different cell-line cells. The CD19-IgG1 MoAb was found to induce modulation of CD19 antigens on Daudi cell line cells more rapidly than did its IgG2a switch variant. We provide evidence that this difference in modulation rate is caused by the expression of Fc gamma receptor II (Fc gamma RII) on these cells. Experiments aimed at elucidating the mechanism of Fc gamma RII involvement in modulation induction by CD19-IgG1 showed that Fc gamma RII did not comodulate with CD19 MoAbs. However, cocrosslinking of CD19 and Fc gamma RII with CD19-IgG1 MoAb resulted in enhanced calcium mobilization in Daudi cells. This increased signal induction accompanies the enhanced capping and subsequent modulation of CD19 antigens. Because Fc gamma RII is expressed in varying densities on malignant B cells in all differentiation stages, our results have implications for the MoAb isotype most suitable for use in MoAb-based therapy of patients with B-cell malignancies. 相似文献
80.
Guangxiang Zang Monica Sandberg Per-Ola Carlsson Nils Welsh Leif Jansson Andreea Barbu 《Upsala journal of medical sciences》2015,120(3):169-180