全文获取类型
收费全文 | 10442篇 |
免费 | 539篇 |
国内免费 | 23篇 |
专业分类
耳鼻咽喉 | 80篇 |
儿科学 | 304篇 |
妇产科学 | 283篇 |
基础医学 | 1825篇 |
口腔科学 | 211篇 |
临床医学 | 986篇 |
内科学 | 1847篇 |
皮肤病学 | 169篇 |
神经病学 | 1092篇 |
特种医学 | 472篇 |
外科学 | 1300篇 |
综合类 | 88篇 |
一般理论 | 3篇 |
预防医学 | 889篇 |
眼科学 | 131篇 |
药学 | 692篇 |
中国医学 | 29篇 |
肿瘤学 | 603篇 |
出版年
2022年 | 65篇 |
2021年 | 143篇 |
2020年 | 92篇 |
2019年 | 128篇 |
2018年 | 157篇 |
2017年 | 121篇 |
2016年 | 159篇 |
2015年 | 209篇 |
2014年 | 268篇 |
2013年 | 379篇 |
2012年 | 639篇 |
2011年 | 676篇 |
2010年 | 391篇 |
2009年 | 357篇 |
2008年 | 603篇 |
2007年 | 630篇 |
2006年 | 614篇 |
2005年 | 634篇 |
2004年 | 576篇 |
2003年 | 513篇 |
2002年 | 527篇 |
2001年 | 102篇 |
2000年 | 57篇 |
1999年 | 98篇 |
1998年 | 124篇 |
1997年 | 91篇 |
1996年 | 80篇 |
1995年 | 86篇 |
1994年 | 68篇 |
1993年 | 63篇 |
1992年 | 46篇 |
1991年 | 66篇 |
1990年 | 57篇 |
1989年 | 53篇 |
1988年 | 44篇 |
1987年 | 44篇 |
1985年 | 53篇 |
1984年 | 55篇 |
1982年 | 45篇 |
1974年 | 44篇 |
1933年 | 71篇 |
1932年 | 59篇 |
1931年 | 57篇 |
1930年 | 52篇 |
1929年 | 44篇 |
1928年 | 45篇 |
1927年 | 52篇 |
1926年 | 54篇 |
1925年 | 49篇 |
1924年 | 52篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
41.
42.
Neuropathological Diagnostic Criteria for Creutzfeldt-Jakob Disease (CJD) and Other Human Spongiform Encephalopathies (Prion Diseases) 总被引:12,自引:0,他引:12
Herbert Budka Adriano Aguzzi Paul Brown Jean-Marie Brucher Orso Bugiani Filippo Gullotta Matti Haltia Jean-Jacques Hauw James W. Ironside Kurt Jellinger Hans A. Kretzschmar Peter L. Lantos Carlo Masullo Wolfgang Schlote Jun Tateishi Roy O. Weller 《Brain pathology (Zurich, Switzerland)》1995,5(4):459-466
Neuropathological diagnostic criteria for Creutzfeldt-Jakob disease (CJD) and other human transmissible spongiform encephalopathies (prion diseases) are proposed for the following disease entities: CJD - sporadic, iatrogenic (recognised risk) or familial (same disease in 1st degree relative): spongiform encephalopathy in cerebral and/or cerebellar cortex and/or subcortical grey matter; or encephalopathy with prion protein (PrP) immuno-reactivity (plaque and/or diffuse synaptic and/or patchy/perivacuolar types). Gerstmann-Sträussler-Scheinker disease (GSS) (in family with dominantly inherited progressive ataxia and/or dementia): encephalo(myelo)pathy with multicentric PrP plaques. Familial fatal insomnia (FFI) (in member of a family with PRNP178 mutation): thalamic degeneration, variable spongiform change in cerebrum. Kuru (in the Fore population). Without PrP data, the crucial feature is the spongiform change accompanied by neuronal loss and gliosis. This spongiform change is characterised by diffuse or focally clustered small round or oval vacuoles in the neuropil of the deep cortical layers, cerebellar cortex or subcortical grey matter, which might become confluent. Spongiform change should not be confused with non-specific spon-giosis. This includes status spongiosus (“spongiform state”), comprising irregular cavities in gliotic neuropil following extensive neuronal loss (including also lesions of “burnt-out” CJD), “spongy” changes in brain oedema and metabolic encephalopathies, and artefacts such as superficial cortical, perineuronal, or perivascular vacuolation; focal changes indistinguishable from spongiform change may occur in some cases of Alzheimer's and diffuse Lewy body diseases. Very rare cases might not be diagnosed by these criteria. Then confirmation must be sought by additional techniques such as PrP immunoblotting, preparations for electron microscopic examination of scrapie associated fibrils (SAF), molecular biologic studies, or experimental transmission. 相似文献
43.
R. Hubert Laeng Heinz A. Gerber Thomas Schaffner Kurt H. Bürki 《Virchows Archiv : an international journal of pathology》1989,415(3):265-273
Summary The present report describes the results of a combined morphological, enzyme- and immunohistochemical analysis of nine cases of malignant non Hodgkin's lymphomas (NHL) clinically presenting as lethal midline granuloma. In a previous report written before antibodies directed against B and T lymphocytes were available, a histiocytic origin of such neoplasms had been suggested. A panel of antibodies reactive with most B cells (L26, MB1, KiB3) and a majority of T cells (MT1, UCHL1) was applied on paraffin sections of formalin fixed tissues as well as antibodies directed against leukocyte common antigen (LCA), myeloid/histiocyte antigen (MAC 387), lysozyme, alpha-1-antitrypsin, alpha-1-antichymotrypsin, S-100 protein, prekeratin and immunoglobulin light chains. Enzyme histochemistry included tests for non-specific acid esterase, acid phosphatase, betaglucuronidase and chloroacetate esterase. As a result, five T, two B and two unclassified (malignant histiocytosis probable) NHL were identified, indicating distinct heterogeneity of NHL as causative disorders in lethal midline granuloma. 相似文献
44.
Sequence information on the genome of porcine epidemic diarrhea virus (PEDV) has only recently been determined. In contrast, very little is known about the viral proteins. In the present report we have identified the membrane glycoprotein (M) of PEDV by use of rabbit anti-peptide sera and transient expression of the cloned M gene in Vero cells and by expression in the baculovirus system. The native M protein of PEDV is incorporated into virions, is N-glycosylated, and migrates with a relative mobility (Mr) of 27 k in polyacrylamide gels. In contrast, the M protein synthesized by recombinant baculoviruses migrates with a Mr of 23 k, that is, with identical mobility as the deglycosylated product of PEDV. Thus, it appears that M protein specified by the recombinant baculovirus is poorly, if at all, glycosylated. Using monoclonal antibodies and rabbit antipeptide sera specific for the N and C termini of the M protein, we were able to show that a 19 k band detected in PEDV-infected cells but not in virions represented a fragment of M from which the C terminus had been cleaved off. Finally, by electron microscopy and immunogold labelling, the relative orientation of M within the virion envelope was determined as NexoCcyt. In conclusion, all of these data strongly support the hypothesis that PEDV should be classified with the group I coronaviruses. 相似文献
45.
Zusammenfassung Es wird über Versuche berichtet, in denen bei freier und artefiziell behinderter Ausatmung Beziehungen zwischen Atemzeitvolumen und alveolärem CO2-Druck aufgestellt wurden. Unter Stenoseatmung werden für gleiche Änderungen des Atemzeitvolumens größere Differenzen des alveolären CO2-Druckes benötigt. Die Verschiebungen werden als Folge der bei erschwerter Atmung erhöhten Atemarbeit gedeutet und nicht auf eine Änderung der Erregbarkeit des Atemzentrums zurückgeführt. Die alveoläre Hypoventilation bei obstruktiven Ventilationsstörungen kann daher — so wird weiter gefolgert — ihren Ursprung in der vermehrten Atemarbeit haben, ohne daß zwingend eine andere pathogenetisch wirksame Ursache diskutiert werden muß. Auf die Bedeutung von Veränderungen des Atemwiderstandes bei der experimentellen Prüfung atemwirksamer Pharmaka wird hingewiesen.Mit Unterstützung der Deutschen Forschungsgemeinschaft. 相似文献
46.
Determination of Dissolved Oxygen in Heterogenous Systems Particularly in Emulsions and Oily Liquids
Foiβner Karl-Heinz Leonhardt Andreas Wegner Gerhard Heinz Bauer Kurt 《Pharmaceutical research》1985,2(1):44-46
The content of dissolved oxygen was determined by four independent methods in a series of non-aqueous or heterogenous systems. The Lex-O2-Content Analyzer represents a fast and simple apparatus that employs a coulometric oxygen assay with Hersch cell detection. A comparison of the results with different methods demonstrates the reliability of the Lex-O2 in the determination of oxygen dissolved in heterogeneous or non-aqueous systems. Therefore, this apparatus can be recommended for the measurement of oxygen in oxygenator or perfusion fluids, as well as in blood substitutes or other oxygen transporting systems. 相似文献
47.
Sotiris Mastoridis María-Carlota Londoño Ada Kurt Elisavet Kodela Elena Crespo John Mason Oriol Bestard Marc Martínez-Llordella Alberto Sánchez-Fueyo 《American journal of transplantation》2021,21(7):2387-2398
In several murine models of transplantation, the “cross-dressing” of recipient antigen presenting cells (APCs) with intact donor major histocompatibility complex (MHC) derived from allograft-released small extracellular vesicles (sEVs) has been recently described as a key mechanism in eliciting and sustaining alloimmune responses. Investigation of these processes in clinical organ transplantation has, however, been hampered by the lack of sensitivity of conventional instruments and assays. We have employed advanced imaging flow cytometry (iFCM) to explore the kinetics of allograft sEV release and the extent to which donor sEVs might induce cross-dressing following liver and kidney transplantation. We report for the first time that recipient APC cross-dressing can be transiently detected in the circulation shortly after liver, but not kidney, transplantation in association with the release of HLA-bearing allograft-derived sEVs. In liver transplant recipients the majority of circulating cells exhibiting donor HLA are indeed cross-dressed cells and not passenger leukocytes. In keeping with experimental animal data, the downstream functional consequences of the transfer of circulating sEVs harvested from human transplant recipients varies depending on the type of transplant and time posttransplant. sEVs released shortly after liver, but not kidney, transplantation exhibit immunoinhibitory effects that could influence liver allograft immunogenicity. 相似文献
48.
Hakan Özkardeş Cankon Germiyanoğlu Ümit Kurt Levent Peşkircioğlu Uğur Altuğ Demokan Erol 《Pediatric surgery international》1995,10(7):488-491
Between 1983 and 1993, 41 patients underwent a first-stage Belt-Fuqua operation for penile hypospadias repair and 39 completed the second stage. Minor complications were observed after the first stage. The primary success rate following the second stage was 82%. Major complications noted after the second stage consisted mainly of fistula formation. The surgical technique is described and alternative methods are discussed. 相似文献
49.
Claudia Hey Ignaz Wessler Kurt Racké 《Naunyn-Schmiedeberg's archives of pharmacology》1995,351(6):651-659
Alveolar macrophages were obtained by broncho-alveolar lavage of isolated rat and rabbit lungs and cultured (2.5 × 106 cells/dish) for 18 h in the absence or presence of bacterial lipopolysaccharides (LPS) alone or in combination with cytokines. Thereafter, accumulation of 3H-citrulline (NO synthase activity) and 3H-ornithine (arginase activity) were determined.During incubation of rat alveolar macrophages with 3H-arginine clear amounts of 3H-citrulline and 3H-ornithine (3.8 and 4.6% of the added 3H-arginine, respectively) were formed and most of these metabolites appeared in the incubation medium (ratios extra-/intracellular of 17 and 70 for 3H-citrulline and 3H-ornithine, respectively). When rat alveolar macrophages had been cultured with LPS the formation of 3H-citrulline was increased about 30-fold and this was accompanied by a reduction in 3H-ornithine formation of about 60%. The effects of LPS were largely attenuated by dexamethasone (10 mol/1). Inhibition of NO synthase by NG-monomethyl-l,-arginine (l-NMMA, 100 mol/1) in LPS treated alveolar macrophages reduced the formation 3H-citrulline by more than 90% and restored the 3H-ornithine formation. After culturing in the presence of LPS the ratios extra/intracellular of 3H-citrulline and 3H-ornithine were markedly enhanced and this effect was not dexamethasone sensitive. During incubation of rabbit alveolar macrophages a marked formation of 3H-ornithine (about 5.3% of the added 3H-arginine), but no significant formation of 3H-citrulline could be detected. Pretreatment with LPS tended to enhance the formation of 3H-ornithine (by 50%) without effects on 3H-citrulline. Rabbit-interferon and/or tumor necrosis factor- present together with LPS during the culture period did not result in a significant 3H-citrulline formation. Under all conditions tested, culture media of rabbit alveolar macrophages did not contain significant amounts of nitrite (less than 0.5 nmol) whereas in culture media of untreated rat alveolar macrophages 22 nmol nitrite (per 18 h) were detected, and LPS induced a 3-fold nitrite accumulation, an effect prevented by dexamethasone.In conclusion, in rabbit alveolar macrophages NO synthase activity was not detectable and could also not be induced by LPS and different cytokines, whereas in rat alveolar macrophages NO synthase was readily inducible. Alveolar macrophages of both species showed marked arginase activity. After induction of marked NO synthase activity, ornithine formation was largely reduced possibly by concomitant inhibition of arginase and/or withdrawn of arginine from arginase. 相似文献
50.