全文获取类型
收费全文 | 365篇 |
免费 | 63篇 |
国内免费 | 9篇 |
专业分类
耳鼻咽喉 | 2篇 |
儿科学 | 24篇 |
妇产科学 | 1篇 |
基础医学 | 71篇 |
口腔科学 | 7篇 |
临床医学 | 42篇 |
内科学 | 80篇 |
皮肤病学 | 18篇 |
神经病学 | 16篇 |
特种医学 | 38篇 |
外科学 | 27篇 |
综合类 | 54篇 |
预防医学 | 28篇 |
眼科学 | 4篇 |
药学 | 13篇 |
中国医学 | 1篇 |
肿瘤学 | 11篇 |
出版年
2022年 | 3篇 |
2021年 | 5篇 |
2020年 | 4篇 |
2019年 | 4篇 |
2018年 | 15篇 |
2017年 | 6篇 |
2016年 | 3篇 |
2015年 | 10篇 |
2014年 | 6篇 |
2013年 | 14篇 |
2012年 | 4篇 |
2011年 | 8篇 |
2010年 | 13篇 |
2009年 | 23篇 |
2008年 | 11篇 |
2007年 | 14篇 |
2006年 | 8篇 |
2005年 | 5篇 |
2004年 | 13篇 |
2003年 | 7篇 |
2002年 | 7篇 |
2001年 | 12篇 |
2000年 | 13篇 |
1999年 | 10篇 |
1998年 | 17篇 |
1997年 | 22篇 |
1996年 | 12篇 |
1995年 | 9篇 |
1994年 | 7篇 |
1993年 | 5篇 |
1992年 | 5篇 |
1991年 | 7篇 |
1990年 | 8篇 |
1989年 | 8篇 |
1988年 | 13篇 |
1987年 | 10篇 |
1986年 | 8篇 |
1985年 | 8篇 |
1984年 | 5篇 |
1983年 | 11篇 |
1982年 | 9篇 |
1981年 | 3篇 |
1976年 | 3篇 |
1971年 | 4篇 |
1970年 | 3篇 |
1969年 | 3篇 |
1967年 | 3篇 |
1960年 | 3篇 |
1958年 | 11篇 |
1957年 | 4篇 |
排序方式: 共有437条查询结果,搜索用时 15 毫秒
11.
Mannucci PM; Lombardi R; Castaman G; Dent JA; Lattuada A; Rodeghiero F; Zimmerman TS 《Blood》1988,71(1):65-70
When normal volunteers or patients with type I von Willebrand disease (VWD) are given desmopressin (DDAVP), a set of larger-than-normal (supranormal) von Willebrand factor (VWF) multimers, similar to those present in VWF-containing cells such as platelets megakaryocytes and endothelial cells, appear transiently in postinfusion plasma. In two kindreds with mild lifelong bleeding symptoms transmitted as an autosomal dominant trait, all ten symptomatic members (but none of the five asymptomatic members) had a supranormal multimeric structure for plasma VWF, apparently identical to that seen for postdesmopressin normal plasma. Plasma factor VIII coagulant activity (VIII:C), VWF antigen (VWF:Ag), ristocetin-induced platelet agglutination, and ristocetin cofactor (RiCof) activity were low. Platelet VWF:Ag and RiCof levels (tested for three patients only) were normal. Bleeding times were normal or slightly prolonged. The patients' platelet multimeric structure was the same as that for normal platelets. After desmopressin infusion the plasma VWF multimeric structure remained supranormal as for preinfusion plasma, with VIII:C VWF:Ag and RiCof increasing markedly over baseline values and disappearing at a normal rate. Examination of the VWF subunit composition from three of these patients indicated that proteolytic processing of their VWF did not differ from normal. This study describes the first variant of VWD with a supranormal multimeric structure. 相似文献
12.
Chamberlain Jayne L. Huda Saif Whittam Daniel H. Matiello Marcelo Morgan B. Paul Jacob Anu 《Journal of neurology》2021,268(5):1665-1665
Journal of Neurology - The original version of this article unfortunately contained a mistake. Fifth sentence of the fourth paragraph in the section “Non-nAChR autoantibody targets in... 相似文献
13.
TS Suhardja L Bae EZ Seah P Cashin DG Croagh 《Annals of the Royal College of Surgeons of England》2015,97(8):568-573
Introduction
The acute surgical model has been trialled in several institutions with mixed results. The aim of this study was to determine whether the acute surgical model provides better outcomes for patients with acute biliary presentation, compared with the traditional emergency surgery model of care.Methods
A retrospective review was carried out of patients who were admitted for management of acute biliary presentation, before and after the establishment of an acute surgical unit (ASU). Outcomes measured were time to operation, operating time, after-hours operation (6pm – 8am), length of stay and surgical complications.Results
A total of 342 patients presented with acute biliary symptoms and were managed operatively. The median time to operation was significantly reduced in the ASU group (32.4 vs 25.4 hours, p=0.047), as were the proportion of operations performed after hours (19.5% vs 2.5%, p<0.001) and the median length of stay (4 vs 3 days, p<0.001). The median operating time, rate of conversion to open cholecystectomy and wound infection rates remained similar.Conclusions
Implementation of an ASU can lead to objective differences in outcomes for patients who present with acute cholecystitis. In our study, the ASU significantly reduced time to operation, the number of operations performed after hours and length of stay. 相似文献14.
A new variant of type II von Willebrand disease with aberrant multimeric structure of plasma but not platelet von Willebrand factor (type IIF) 总被引:2,自引:0,他引:2
A patient with a lifelong bleeding disorder was diagnosed as having Type II von Willebrand disease. The larger multimers of von Willebrand factor were absent from her plasma but present in platelets. A high- resolution electrophoretic technique was used to study the complex structure of individual von Willebrand factor multimers. In normal plasma, each multimer could be resolved into five bands: a more intense central one and four less intense, two moving faster and two slower than the central band. In normal platelets, each multimer could also be resolved into five bands. The central one had a mobility similar to that in plasma, whereas the four satellite bands had a mobility that differed from that of the corresponding plasma bands. In the patient, platelet von Willebrand factor antigen content and ristocetin cofactor activity were normal, and von Willebrand factor showed the same structure of individual multimers as seen in normal platelets. On the other hand, plasma von Willebrand factor antigen and ristocetin cofactor activity were decreased, and the structure of individual von Willebrand factor multimers was different from that of normal plasma and similar to that seen in normal and patient's platelets. After infusion of 1-deamino-8-D-arginine vasopressin, the largest von Willebrand factor multimers, as well as new satellite bands with a mobility similar to those in normal plasma, appeared in the patient plasma, and the levels of von Willebrand factor antigen and ristocetin cofactor activity became normal. Yet no relevant change in the prolonged bleeding time was observed. This new variant of von Willebrand disease, therefore, is characterized by the presence of a dysfunctional von Willebrand factor molecule that exhibits unique structural abnormalities in plasma but appears to be normal in platelets. The designation of Type IIF is proposed for this type of von Willebrand disease in accordance with the terminology that has been previously used. 相似文献
15.
Allelic variation in human mitochondrial genes based on patterns of restriction site polymorphism. 总被引:9,自引:3,他引:9 下载免费PDF全文
T S Whittam A G Clark M Stoneking R L Cann A C Wilson 《Proceedings of the National Academy of Sciences of the United States of America》1986,83(24):9611-9615
Restriction maps of 145 human mtDNAs representing samples from five geographic regions were used to construct multilocus genotypes for 28 genetic loci of the mitochondrial genome. Alleles were defined as distinct combinations of the presence or absence of polymorphic restriction sites within each locus. The 28 loci included 13 genes encoding proteins, 10 genes specifying tRNAs, 2 genes specifying rRNAs, and 3 noncoding regions consisting of the D loop, the light strand origin of replication, and the 5' noncoding sequence. In 35 comparisons of allele frequency distributions to expected distributions predicted by neutral mutation theory (assuming an infinite alleles model), the results revealed that most genetic diversity values (71%) fell within the range predicted by the neutral model; however, excesses in the frequencies of common alleles and in the number of singleton alleles within populations were observed at specific loci. Departures from the neutral mutation model are most readily explained by the effects of the recent expansion of the human population and the action of purifying selection. Coefficients of population differentiation suggest that gene flow of mtDNA types between certain geographic regions may be limited. 相似文献
16.
17.
R George D Ganesan TS Amarnath R Balamurugan 《Annals of the Royal College of Surgeons of England》2013,95(6):e111
The following abstracts won prizes at the 153rd East Midlands Surgical Society meeting held on 9 November 2012 at Leicester General Hospital. First prize was won by George et al. The paper by Ogunbiyi et al was placed second and the paper by Khanna et al was placed third. 相似文献
18.
Ultrastructural localization of human platelet thrombospondin, fibrinogen, fibronectin, and von Willebrand factor in frozen thin section 总被引:7,自引:0,他引:7
We have investigated the localization of thrombospondin (TSP), fibrinogen, fibronectin, and von Willebrand factor in human platelets by transmission electron microscopy of antibody-stained ultrathin frozen sections. In negatively stained thin sections, alpha granules were identified on the basis of their smooth, roughly spherical shape, size, single limiting electron-lucent 100 A membrane, and frequent presence of electron-dense nucleoid. In contrast, mitochondria exhibited characteristic double membranes and cristae. Sections were separately stained with affinity-purified polyclonal antibodies to these proteins as well as with three monoclonal anti-TSP antibodies. Antibody specificity was documented in radioimmunoassays, by immunofluorescent cross-blocking, and by staining of bands of appropriate mobility in Western blots of whole platelets. Bound antibody was visualized using a 5-nm colloidal gold-avidin conjugate. In resting cells, staining of virtually all alpha granules was observed for all four proteins. In contrast, consistent staining was absent from other organelles, including plasma membranes, mitochondria, and vacuolar structures that may represent the open canalicular system. 相似文献
19.
The color complementation assay (CCA) is a method of allele-specific DNA amplification by which competitive priming and extension of fluorescently labeled oligonucleotide primers determine the color of DNA amplification product. This diagnostic method precludes the need for radioisotopes, electrophoresis, and multiple high-stringency reaction conditions. The multiplicity of mutant globin genes present in Southeast Asians complicates clinical diagnosis and underscores the importance of DNA-based diagnostic methods. We have applied CCA to distinguish beta A and beta E alleles. Competing 15mer primers were a fluorescein-labeled complement to beta A and a rhodamine-labeled complement to beta E, identical except for their central nucleotides. A common unlabeled primer was used to amplify DNA product, the color of which was determined by the perfectly complementary primer. Color photography and spectrofluorometry, as well as a method of black-white photography that we developed to distinguish fluorescein- and rhodamine- labeled DNA, were used to record results. We applied CCA to define the complex genotype of a Thai woman with thalassemia intermedia, 96% HbE, and 4% HbF whose possible genotypes included several permutations of alpha-thalassemia, beta-thalassemia, and beta E genes. zeta-Globin gene mapping of DNA doubly digested with Bg/II and Asp 718 showed the -alpha 3.7/--SEA genotype, and CCA confirmed homozygous beta E/beta E. The CCA is useful for diagnosing the compound hemoglobin genotypes of Southeast Asians and could be applied also to prenatal diagnosis in this population. 相似文献
20.
Four patients with Philadelphia (Ph') positive chronic myeloid leukemia (CML) were studied before, after, and on relapse following allogeneic bone marrow transplantation (BMT). Southern analysis of DNA from cells collected before and at relapse after BMT was performed in order to investigate the origin of the leukemia at relapse. Using minisatellite probes we showed that the relapse occurred in cells of host origin in all four patients and this was confirmed with a Y chromosome specific probe in two male patients who had a female donor. Furthermore, using two probes for the breakpoint cluster region (bcr) on chromosome 22, we showed that leukemic cells at relapse bore identical rearrangements to those in the disease at time of presentation of each patient. We conclude that relapse in all four patients is due to re-emergence of the original leukemic clone. 相似文献