全文获取类型
收费全文 | 4657篇 |
免费 | 371篇 |
国内免费 | 16篇 |
专业分类
耳鼻咽喉 | 51篇 |
儿科学 | 156篇 |
妇产科学 | 90篇 |
基础医学 | 752篇 |
口腔科学 | 103篇 |
临床医学 | 442篇 |
内科学 | 986篇 |
皮肤病学 | 95篇 |
神经病学 | 520篇 |
特种医学 | 104篇 |
外科学 | 441篇 |
综合类 | 12篇 |
一般理论 | 1篇 |
预防医学 | 466篇 |
眼科学 | 103篇 |
药学 | 329篇 |
中国医学 | 6篇 |
肿瘤学 | 387篇 |
出版年
2024年 | 9篇 |
2023年 | 56篇 |
2022年 | 81篇 |
2021年 | 137篇 |
2020年 | 107篇 |
2019年 | 128篇 |
2018年 | 139篇 |
2017年 | 136篇 |
2016年 | 123篇 |
2015年 | 150篇 |
2014年 | 160篇 |
2013年 | 217篇 |
2012年 | 391篇 |
2011年 | 399篇 |
2010年 | 202篇 |
2009年 | 176篇 |
2008年 | 299篇 |
2007年 | 331篇 |
2006年 | 262篇 |
2005年 | 289篇 |
2004年 | 300篇 |
2003年 | 256篇 |
2002年 | 249篇 |
2001年 | 29篇 |
2000年 | 24篇 |
1999年 | 27篇 |
1998年 | 43篇 |
1997年 | 33篇 |
1996年 | 27篇 |
1995年 | 20篇 |
1994年 | 25篇 |
1993年 | 28篇 |
1992年 | 21篇 |
1991年 | 19篇 |
1990年 | 12篇 |
1989年 | 9篇 |
1988年 | 11篇 |
1987年 | 15篇 |
1986年 | 6篇 |
1985年 | 9篇 |
1984年 | 8篇 |
1983年 | 8篇 |
1982年 | 9篇 |
1981年 | 4篇 |
1980年 | 4篇 |
1979年 | 4篇 |
1978年 | 5篇 |
1977年 | 8篇 |
1976年 | 5篇 |
1965年 | 6篇 |
排序方式: 共有5044条查询结果,搜索用时 17 毫秒
11.
Purpose: Conjunctival hyperemia has been reported as a frequent side effect of bimatoprost, a prostamide with efficacious ocular hypotensive action. To investigate the possible inflammatory basis of the hyperemia, we analysed, by means of light microscopy, the conjunctival specimens of patients who developed ocular hyperemia during bimatoprost therapy and who underwent cataract surgery. Methods: Patients were divided in two groups; 相似文献
12.
Alexandre Castro-Caldas Paul Delwaide Wolfgang Jost Marcelo Merello Adrian Williams Paolo Lamberti Miguel Aguilar Susanna Del Signore Pierre Cesaro 《Movement disorders》2006,21(4):500-509
Dopamine agonists have been recommended as early treatment for Parkinson's disease (PD), alone or combined with levodopa. Piribedil is a non-ergot selective D(2)/D(3) agonist with alpha(2) antagonist properties shown to be effective in the treatment of PD. This 12-month international, randomized, double-blind trial aimed to assess the efficacy of piribedil 150 mg versus bromocriptine 25 mg, in early combination with levodopa in Stage I to III PD patients. Motor efficacy was assessed using the Unified Parkinson's Disease Rating Scale (UPDRS III, Items 18-31) as improvement from baseline. Response rate was defined as a 30% improvement. Among the 425 randomly assigned patients, 178 were also included in a substudy on cognitive follow-up evaluated by a dysexecutive syndrome oriented battery. A relevant improvement in UPDRS III over the 12-month study duration was observed both in the piribedil and bromocriptine groups (-7.9 +/- 9.7 points from baseline versus -8.0 +/- 9.5; not significant [n.s.]) with a response rate of 58.4% and 55.3% (n.s.), respectively. Piribedil and bromocriptine resulted in similar improvement on all UPDRS III subscores. Piribedil patients required less levodopa dose increase than those on bromocriptine. Cognitive performance remained generally unchanged in both groups, with a significant effect of piribedil limited to the Wisconsin Card Sorting Test. An overall good tolerability of piribedil was observed. Early combination of piribedil 150 mg with levodopa resulted in significant long-term improvement of all motor symptoms in PD patients insufficiently controlled by levodopa alone. Taking into account both efficacy and acceptability in the long-term, piribedil proved in this bromocriptine controlled study to be an effective and safe treatment for PD. 相似文献
13.
Submassive hepatic necrosis associated with the use of progabide: A GABA receptor agonist 总被引:2,自引:0,他引:2
Santiago J. Munoz MD Ruggero Fariello MD Willis C. Maddrey MD 《Digestive diseases and sciences》1988,33(3):375-380
Progabide, a recently introduced gamma-aminobutyric acid mimetic, is currently undergoing clinical evaluation for a variety of convulsive disorders. We describe a patient in whom severe hepatic failure developed after four weeks of Progabide therapy. The patient's course was marked by encephalopathy, jaundice, hypoglycemia, markedly elevated serum aminotransferase levels, and prolongation of the prothrombin time. Liver biopsy showed extensive hepatocellular necrosis. The patient recovered slowly after discontinuation of the drug. The finding of eosinophilia and increased serum IgE suggests an immunologically mediated mechanism for the Progabide-induced hepatic injury. Alternatively, the lipophilic moiety of Progabide may interact with hepatocyte cell membrane lipids leading to toxic injury. We conclude that Progabide may occasionally cause severe hepatic injury. 相似文献
14.
Ruggero de Paulis Fabrizio Tomai Fabio Bertoldo Anna S Ghini Raffaele Scaffa Paolo Nardi Luigi Chiariello 《European journal of cardio-thoracic surgery》2004,26(1):66-72
OBJECTIVES: The sinuses of Valsalva are known to contribute to the normal function of the aortic valve. Little is known about their role in promoting coronary artery blood flow. The aim of this study was to compare coronary artery flow characteristics among patients undergoing a Bentall operation by means of a conventional cylindrical Dacron conduit or with a new conduit with pseudosinuses of Valsalva or in patients retaining their natural sinuses of Valsalva after aortic valve and supracoronary ascending aorta replacement. METHODS: One year after a Bentall procedure with a standard cylindrical Dacron conduit (7 patients, group A) or with the new conduit (7 patients, group B), or after aortic valve and ascending aortic replacement (control group, 7 patients, group C) coronary flow velocity reserve and diastolic to systolic time integral ratio at baseline and after maximal hyperemia (with 40 microg of adenosine) were assessed by using a 0.014-in. Doppler guidewire positioned in the middle portion of the left anterior descending coronary artery. All patients were in NYHA class I, sinus rhythm and free of coronary disease. RESULTS: Arterial blood pressures and heart rate were comparable among groups. Intracoronary Doppler measurements did not show any significant difference in coronary vascular reserve between the three groups (3.6+/-0.4 vs 3.1+/-0.7 vs 3.7+/-0.5, P = 0.2). A greater diastolic component at baseline was present in group B patients (5.5+/-1.9 vs 3.5+/-0.9 in group A and 3.7+/-0.9 in group C, P = 0.024). After maximal hyperemia the diastolic component increased slightly in group A patients (8%) while both in groups B and C significantly decreased (-15 and -20%, respectively) (P = 0.017). CONCLUSIONS: The presence of pseudosinuses of Valsalva does not influence coronary flow reserve. After maximal coronary vasodilation the increase in the systolic component of coronary flow is more evident in the presence of sinuses or pseudosinuses of Valsalva, thus suggesting that coronary flow pattern may be affected by the presence of sinuses. 相似文献
15.
Imaging of acute mesenteric ischemia using multidetector CT and CT angiography in a porcine model 总被引:3,自引:0,他引:3
David E. Rosow M.D. Dushyant Sahani M.D. Oliver Strobel M.D. Sanjeeva Kalva M.D. Mari Mino-Kenudson M.D. Nagaraj S. Holalkere M.D. Guido Alsfasser M.D. Sanjay Saini M.D. Susanna I. Lee M.D. Peter R. Mueller M.D. Carlos Fernándezdel Castillo M.D. Andrew L. Warshaw M.D. Sarah P. Thayer M.D. Ph.D. 《Journal of gastrointestinal surgery》2005,9(9):1262-1275
Acute mesenteric ischemia, a frequently lethal disease, requires prompt diagnosis and intervention for favorable clinical
outcomes. This goal remains elusive due, in part, to lack of a noninvasive and accurate imaging study. Traditional angiography
is the diagnostic gold standard but is invasive and costly. Computed tomography (CT) is readily available and noninvasive
but has shown variable success in diagnosing this disease. The faster scanning time of multidetector row CT (M.D.CT) greatly
facilitates the use of CT angiography (CTA) in the clinical setting. We sought to determine whether M.D.CT-CTA could accurately
demonstrate vascular anatomy and capture the earliest stages of mesenteric ischemia in a porcine model. Pigs underwent embolization
of branches of the superior mesenteric artery, then imaging by M.D.CT-CTA with three-dimensional reconstruction protocols.
After scanning, diseased bowel segments were surgically resected and pathologically examined. Multidetector row CT and CT
angiography reliably defined normal and occluded mesenteric vessels in the pig. It detected early changes of ischemia including
poor arterial enhancement and venous dilatation, which were seen in all ischemic animals. The radiographic findingsd—compared
with pathologic diagnosesd—predicted ischemia, with a positive predictive value of 92%. These results indicate that M.D.CT-CTA
holds great promise for the early detection necessary for successful treatment of acute mesenteric ischemia.
Presented at the Forty-Sixth Annual Meeting of The Society for Surgery of the Alimentary Tract, Chicago, Illinois, May 14–18,
2005 (oral presentation).
Supported by the Karin Grunebaum Research Fellowship, Harvard Medical School (D.E.R.), the German Research Fellowship, German
Research Foundation STR 690/1-1 (O.S.), and the Phillip H. Meyers Grant from the Society of Gastrointestinal Radiologists
(S.P.T.). 相似文献
16.
17.
Susanna L. Matsen Charles J. Yeo Ralph H. Hruban Michael A. Choti 《Journal of gastrointestinal surgery》2005,9(2):270-279
Humoral hypercalcemia of malignancy is widely associated with tumor production of parathyroid hormone related protein (PTH-rP).
This peptide functions in endocrine, autocrine and paracrine mechanisms in a manner similar to PTH; increasing renal uptake
of calcium, decreasing retention of phosphorous, and stimulating adenylate cyclase and phospholipase C. Although PTH-rP production
has been well documented in neoplasms of the exocrine pancreas, we present here two cases of endocrine pancreatic neoplasms
elaborating PTH-rP. We then review the literature of previous cases and delve into the pathophysiology of this peptide. 相似文献
18.
Molecular Cloning and Characterization of the Genes Coding for the Highly Immunogenic Cluster of 90-Kilodalton Envelope Proteins from the Chlamydia psittaci Subtype That Causes Abortion in Sheep 总被引:5,自引:0,他引:5
下载免费PDF全文
![点击此处可从《Infection and immunity》网站下载免费的PDF全文](/ch/ext_images/free.gif)
David Longbottom Mary Russell Susanna M. Dunbar Gareth E. Jones Alan J. Herring 《Infection and immunity》1998,66(4):1317-1324
Proteins present in the outer membrane of chlamydiae that are involved in mucosal epithelial cell infection must clearly be identified and characterized if we are to understand and modify the pathogenic mechanisms utilized by these organisms. We have identified and isolated a family of four genes encoding putative outer membrane proteins (POMPs), a group of proteins of approximately 90 kDa present in the outer membrane of the subtype of Chlamydia psittaci that causes ovine enzootic abortion (strain S26/3). These proteins, although minor components, are major immunogens, as shown by the immunoblotting of chlamydial outer membrane complexes with postabortion sheep sera, and are therefore potential diagnostic and/or protective antigen candidates. Immunoblotting of the expressed amino- and carboxy-terminal halves of one of the POMPs with postabortion sheep sera showed that the major humoral immune response appeared to be directed solely against the amino-terminal half. This result, in combination with the positive immunofluorescence staining of S26/3-infected cells using POMP-specific (specific to the amino-terminal half of the proteins) monoclonal antibodies, suggests the probable surface localization of the POMPs and, more specifically, the surface exposure of the amino-terminal half of these proteins. The four pomp genes are highly homologous, sharing 82 to 100% similarity with each other (two of the genes are identical). Genes with strong and weak homologies were also detected in C. psittaci avian and feline pneumonitis strains, respectively. No pomp homologs were found in strains of C. trachomatis and C. pneumoniae, but this does not preclude their existence. The absence of homology with various subtypes of C. pecorum, which complicate the diagnosis of the ovine abortion subtype, indicates the possible suitability of the these 90-kDa proteins as serodiagnostic antigens. 相似文献
19.
The position of pulmonary carcinoids within the spectrum of neuroendocrine tumors of the lung and other tissues 总被引:3,自引:0,他引:3
Ullmann R Petzmann S Klemen H Fraire AE Hasleton P Popper HH 《Genes, chromosomes & cancer》2002,34(1):78-85
Bronchopulmonary carcinoids comprise 25% of all human carcinoids. The World Health Organization divides them into typical (TC) and atypical forms (ATC), distinguished by differences in mitotic counts lower or higher than 2/2 mm(2) and the presence or absence of necrosis. The reproducibility of this classification with respect to the borderline cases with 1-2 mitotic counts/2 mm(2) has been questioned. We have analyzed 15 TCs and 20 ATCs by comparative genomic hybridization. Loss of 11q was the most frequent aberration in ATC (55%), but was observed only twice in TC (13%). Deletions of 3p were seen only in ATC (25%). Meta-analysis of our data and data from 218 neuroendocrine tumors and 50 non-small-cell lung carcinomas obtained from the literature revealed differences between carcinoids and carcinomas. For example, loss of 5q is frequent in lung carcinomas (75%) but is rarely seen in carcinoids (1.4%). Deletions of 11q are less frequent in neuroendocrine lung carcinomas than in ATC. To obtain a more objective survey of the relationship of pulmonary carcinoids to other neuroendocrine tumors and lung carcinomas, we created a hierarchical clustering dendrogram. This statistical approach resulted in a clear separation of carcinoids and carcinomas, which both built up different clusters. In summary, this study demonstrates the benefit of chromosomal analysis supplementary to the diagnosis of bronchopulmonary carcinoids. We also identified the feasibility of hierarchical clustering to get some clues on relationship between different tumor types. This study further argues against a transition of ATC to high-grade neuroendocrine lung carcinoma. 相似文献
20.
Detection of antibodies specific to an antigenic cell wall galactomannoprotein for serodiagnosis of Aspergillus fumigatus aspergillosis 总被引:3,自引:0,他引:3
下载免费PDF全文
![点击此处可从《Journal of clinical microbiology》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Chan CM Woo PC Leung AS Lau SK Che XY Cao L Yuen KY 《Journal of clinical microbiology》2002,40(6):2041-2045
Aspergilloma and invasive aspergillosis are important opportunistic infections caused by Aspergillus species, among which Aspergillus fumigatus is the most common species associated with human disease. We developed an enzyme-linked immunosorbent assay (ELISA)-based antibody assay with Afmp1p, a purified recombinant antigenic cell wall galactomannoprotein of A. fumigatus. Evaluation of the test with guinea pig sera against A. fumigatus and other pathogenic fungi indicated that this assay was specific for A. fumigatus. Clinical evaluation revealed that the assay was 100% sensitive for patients with aspergilloma and 33.3% sensitive for patients with invasive aspergillosis. No false-positive results were found for serum samples from 80 healthy blood donors, 6 patients with typhoid fever, 4 patients with melioidosis, 20 patients with penicilliosis marneffei, 5 patients with candidiasis, and 4 patients with cryptococcosis, indicating a high specificity of the test. Thus, this ELISA-based test for the detection of anti-Afmp1p antibody can be of significant value as a diagnostic for aspergillosis. 相似文献