全文获取类型
收费全文 | 1463篇 |
免费 | 124篇 |
国内免费 | 5篇 |
专业分类
耳鼻咽喉 | 9篇 |
儿科学 | 36篇 |
妇产科学 | 25篇 |
基础医学 | 242篇 |
口腔科学 | 26篇 |
临床医学 | 181篇 |
内科学 | 338篇 |
皮肤病学 | 25篇 |
神经病学 | 131篇 |
特种医学 | 53篇 |
外科学 | 164篇 |
综合类 | 21篇 |
预防医学 | 133篇 |
眼科学 | 36篇 |
药学 | 86篇 |
中国医学 | 2篇 |
肿瘤学 | 84篇 |
出版年
2021年 | 20篇 |
2020年 | 12篇 |
2019年 | 12篇 |
2018年 | 24篇 |
2017年 | 17篇 |
2016年 | 27篇 |
2015年 | 41篇 |
2014年 | 28篇 |
2013年 | 30篇 |
2012年 | 57篇 |
2011年 | 59篇 |
2010年 | 26篇 |
2009年 | 36篇 |
2008年 | 51篇 |
2007年 | 65篇 |
2006年 | 37篇 |
2005年 | 58篇 |
2004年 | 53篇 |
2003年 | 46篇 |
2002年 | 52篇 |
2001年 | 37篇 |
2000年 | 49篇 |
1999年 | 49篇 |
1998年 | 33篇 |
1997年 | 25篇 |
1996年 | 26篇 |
1995年 | 21篇 |
1994年 | 30篇 |
1993年 | 22篇 |
1992年 | 31篇 |
1991年 | 22篇 |
1990年 | 31篇 |
1989年 | 24篇 |
1988年 | 35篇 |
1987年 | 33篇 |
1986年 | 31篇 |
1985年 | 33篇 |
1984年 | 19篇 |
1983年 | 24篇 |
1982年 | 16篇 |
1981年 | 15篇 |
1980年 | 15篇 |
1979年 | 15篇 |
1978年 | 18篇 |
1976年 | 12篇 |
1975年 | 16篇 |
1973年 | 11篇 |
1971年 | 15篇 |
1969年 | 12篇 |
1966年 | 10篇 |
排序方式: 共有1592条查询结果,搜索用时 15 毫秒
21.
Christopher Sie Ravi Kant Christian Peter Andreas Muschaweckh Monika Pfaller Lucy Nirschl Helena Domínguez Moreno Tereza Chadimov Gildas Lepennetier Tanja Kuhlmann Rupert
llinger Thomas Engleitner Roland Rad Thomas Korn 《The Journal of experimental medicine》2022,219(8)
In certain instances, Th17 responses are associated with severe immunopathology. T cell–intrinsic mechanisms that restrict pathogenic effector functions have been described for type 1 and 2 responses but are less well studied for Th17 cells. Here, we report a cell-intrinsic feedback mechanism that controls the pathogenicity of Th17 cells. Th17 cells produce IL-24, which prompts them to secrete IL-10. The IL-10–inducing function of IL-24 is independent of the cell surface receptor of IL-24 on Th17 cells. Rather, IL-24 is recruited to the inner mitochondrial membrane, where it interacts with the NADH dehydrogenase (ubiquinone) 1 α subcomplex subunit 13 (also known as Grim19), a constituent of complex I of the respiratory chain. Together, Grim19 and IL-24 promote the accumulation of STAT3 in the mitochondrial compartment. We propose that IL-24–guided mitochondrial STAT3 constitutes a rheostat to blunt extensive STAT3 deflections in the nucleus, which might then contribute to a robust IL-10 response in Th17 cells and a restriction of immunopathology in experimental autoimmune encephalomyelitis. 相似文献
22.
Deformable sickle erythrocytes have been reported by Mohandas and Evans to be more adherent to vascular endothelium than rigid irreversibly sickled cells (ISC). To define the clinical implications of this finding we have determined genetic, hematological, clinical, and rheological characteristics of sickle erythrocytes obtained from 65 patients with sickle cell anemia and fetal hemoglobin (Hb F) levels less than 15%. The alpha-globin gene number had a significant effect on the hematological parameters, the percentage of dense cells, ISC number, and HB A2 levels. The presence or absence of alpha thalassemia, however, had no effect on the frequency and severity of the sickle cell painful crisis (r = 0.06, P greater than .05). RBC deformability, determined by an ektacytometer, showed great heterogeneity among patients with three or four alpha-globin genes. Linear regression analyses of the data showed significant positive correlation of the frequency and severity of the painful crisis with RBC deformability (r = 0.49, P less than .001), and negative correlations with the percentage of dense cells (r = -0.37, P = .002), and the percentage of ISC (r = -0.46, P less than .001). We propose that the more deformable the sickle RBC are, the greater their adherence to vascular endothelium, and the more they cause vaso-occlusive crises, RBC deformability and the percentage of dense cells (or ISC) seem to have a predictive value of the frequency and severity of painful crises in sickle cell anemia. 相似文献
23.
24.
Korn ED 《Proceedings of the National Academy of Sciences of the United States of America》2000,97(23):12559-12564
Myosins, a large family of actin-based motors, have one or two heavy chains with one or more light chains associated with each heavy chain. The heavy chains have a (generally) N-terminal head domain with an ATPase and actin-binding site, followed by a neck domain to which the light chains bind, and a C-terminal tail domain through which the heavy chains self-associate and/or bind the myosin to its cargo. Approximately 140 members of the myosin superfamily have been grouped into 17 classes based on the sequences of their head domains. I now show that a phylogenetic tree based on the sequences of the combined neck and tail domains groups 144 myosins, with a few exceptions, into the same 17 classes. For the nine myosin classes that have multiple members, phylogenetic trees based on the head domain or the combined neck/tail domains are either identical or very similar. For class II myosins, very similar phylogenetic trees are obtained for the head, neck, and tail domains of 47 heavy chains and for 29 essential light chains and 19 regulatory light chains. These data strongly suggest that the head, neck, and tail domains of all myosin heavy chains, and light chains at least of class II myosins, have coevolved and are likely to be functionally interdependent, consistent with biochemical evidence showing that regulated actin-dependent MgATPase activity of Dictyostelium myosin II requires isoform specific interactions between the heavy chain head and tail and light chains. 相似文献
25.
Sustained, retransplantable, multilineage engraftment of highly purified adult human bone marrow stem cells in vivo 总被引:4,自引:8,他引:4
Civin CI; Almeida-Porada G; Lee MJ; Olweus J; Terstappen LW; Zanjani ED 《Blood》1996,88(11):4102-4109
Data from many laboratory and clinical investigations indicate that CD34+ cells comprise approximately 1% of human bone marrow (BM) mononuclear cells, including the progenitor cells of all the lymphohematopoietic lineages and lymphohematopoietic stem cells (stem cells). Because stem cells are an important but rare cell type in the CD34+ cell population, investigators have subdivided the CD34+ cell population to further enrich stem cells. The CD34+/CD38- cell subset comprises less than 10% of human CD34+ adult BM cells (equivalent to < 0.1% of marrow mononuclear cells), lacks lineage (lin) antigens, contains cells with in vitro replating capacity, and is predicted to be highly enriched for stem cells. The present investigation tested whether the CD34+/CD38- subset of adult human marrow generates human hematopoiesis after transfer to preimmune fetal sheep. CD34+/ CD38- cells purified from marrow using immunomagnetic microspheres or fluorescence-activated cell sorting generated easily detectable, long- term, multilineage human hematopoiesis in the human-fetal sheep in vivo model. In contrast, transfer of CD34+/CD38+ cells to preimmune fetal sheep generated only short-term human hematopoiesis, possibly suggesting that the CD34+/CD38+ cell population contains relatively early multipotent hematopoletic progenitor cells, but not stem cells. This work extends the prior in vitro evidence that the earliest cells in fetal and adult human marrow lack CD38 expression. In summary, the CD34+/ CD38- cell population has a high capacity for long-term multilineage hematopoietic engraftment, suggesting the presence of stem cells in this minor adult human marrow cell subset. 相似文献
26.
A. B. Elfant M.D. C. Korn R.N. L. Mendez M.D. M. J. Pello M.D. S. R. Peikin M.D. 《Diseases of the colon and rectum》1995,38(1):1-3
PURPOSE: The aim of this study was to determine if recall of informed consent is affected by the timing of obtaining informed consent before endoscopic procedures. METHODS: Sixty patients scheduled for colonoscopy or esophagogastroduodenoscopy were enrolled in this prospective, randomized study. Each patient received informed consent 24 to 72 hours or immediately before the procedure, and follow-up occurred one to three days postprocedure. RESULTS: There was no statistically significant difference in recall of informed consent or the individual elements of informed consent (indication, risks, benefits, alternatives) between the two groups. CONCLUSION: Recall of informed consent is similar whether consent is obtained immediately or several days before endoscopie procedures.Presented in part at the 10th World Congresses of Gastroenterology, Los Angeles, California, October 2 to 7, 1994. 相似文献
27.
Ishikawa T Cheng N Liu X Korn ED Steven AC 《Proceedings of the National Academy of Sciences of the United States of America》2004,101(33):12189-12194
Acanthamoeba myosin IC (AMIC) is a single-headed myosin comprised of one heavy chain (129 kDa) and one light chain (17 kDa). The heavy chain has head, neck (light chain-binding), and tail domains. The tail consists of four subdomains: a basic region (BR) (23 kDa) and two Gly/Pro/Ala-rich (GPA) regions, GPA1 (6 kDa) and GPA2 (15 kDa), flanking an Src homology 3 region (6 kDa). Although the AMIC head is similar in sequence, structure, and function (ATPase motor) to other myosin heads, the organization of the tail has been less clear as has its function beyond an assumed role in binding interaction partners, e.g., the BR has a membrane affinity and the GPA components bind F-actin in an ATP-independent manner. To investigate the spatial arrangement of subdomains in the tail, we have used cryo-electron microscopy and image reconstruction to compare actin filaments decorated with WT AMIC and tail-truncated mutants of various lengths. The BR forms an oval-shaped feature, approximately 40 A long, that diverges obliquely from the head, extending azimuthally around the actin filament and toward its barbed end. GPA2 and GPA1 are located together on the inner (actin-proximal) side of the tail, close enough to act in concert in binding the same or another actin filament. The outer face of the BR is strategically exposed for membrane or vesicle binding. 相似文献
28.
Juliette A.L. Santing Crispijn L. Van den Brand Korné Jellema 《The Journal of emergency medicine》2021,60(3):285-291
BackgroundEmergency departments (EDs) are faced with a growing number of patients with traumatic brain injury (TBI) using direct oral anticoagulants (DOACs). However, there remains uncertainty about the bleeding risk, rate of hematoma expansion, and the efficacy of reversal strategies in these patients.ObjectiveThis study aims to identify the risk of traumatic hemorrhagic complications in patients with TBI using DOACs.MethodsIn this retrospective study we included patients with TBI. All TBI patients were using DOACs, attended one of the three EDs of our hospital between January 2016 and October 2019, and received a computed tomography (CT) scan of the brain. The primary outcome was any traumatic intracranial hemorrhage on CT. Secondary outcomes were the use of reversal agents, secondary neurological deterioration, a neurosurgical intervention within 30 days after the injury, length of stay (LOS), Glasgow Outcome Scale (GOS) at discharge, and mortality.ResultsOf the included patients (N = 316), 24 patients (7.6%, 95% confidence interval [CI] 4.2–9.8) presented with a traumatic intracranial hematoma (ICH). Seven patients (2.2%, 95% CI 0.6–3.8) received a reversal agent and 1 patient (0.3%, 95% CI ?0.3–0.9) underwent a neurosurgical intervention. Of the 24 patients with a traumatic ICH, progression of the lesion was seen in 6 patients (1.9%, 95% CI 0.4–3.4). The mean LOS was 6.5 days (95% CI 3.0–10.1) and the mean GOS at discharge was 4 (95% CI 3.6–4.6). Death occurred in 1 patient (0.3%, 95% CI ?0.3–0.9) suffering from an ICH.ConclusionBased on the present findings it can be postulated that TBI patients using DOACs have a low risk for ICH. Hematoma progression occurred, however, in a substantial number of patients. Considering the retrospective nature of the present study, future prospective trials are needed to confirm this finding. 相似文献
29.
Andreas E. Kremer Anita N. Kremer Carsten Willam Simon Völkl Johan Verhagen Susanne Achenbach Edith D. van der Meijden Vanessa Lang Michael Aigner Clara Maier Matthias Tenbusch Klaus Korn Gloria Lutzny-Geier Silvia Spoerl Richard Strauß Marcel Vetter Klaus Überla Markus F. Neurath Andreas Mackensen Mario Schiffer Holger Hackstein 《European journal of immunology》2021,51(10):2478-2484
Treatment with convalescent plasma has been shown to be safe in coronavirus disease in 2019 (COVID-19) infection, although efficacy reported in immunocompetent patients varies. Nevertheless, neutralizing antibodies are a key requisite in the fight against viral infections. Patients depleted of antibody-producing B cells, such as those treated with rituximab (anti-CD20) for hematological malignancies, lack a fundamental part of their adaptive immunity. Treatment with convalescent plasma appears to be of general benefit in this particularly vulnerable cohort. We analyzed clinical course and inflammation markers of three B-cell-depleted patients suffering from COVID-19 who were treated with convalescent plasma. In addition, we measured serum antibody levels as well as peripheral blood CD38/HLA-DR-positive T-cells ex vivo and CD137-positive T-cells after in vitro stimulation with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-derived peptides in these patients. We observed that therapy with convalescent plasma was effective in all three patients and analysis of CD137-positive T-cells after stimulation with SARS-CoV-2 peptides showed an increase in peptide-specific T-cells after application of convalescent plasma. In conclusion, we here demonstrate efficacy of convalescent plasma therapy in three B-cell-depleted patients and present data that suggest that while application of convalescent plasma elevates systemic antibody levels only transiently, it may also boost specific T-cell responses. 相似文献
30.
In vivo analysis of the vascular pattern of the superficial temporal artery based on digital subtraction angiography 下载免费PDF全文