全文获取类型
收费全文 | 308篇 |
免费 | 15篇 |
国内免费 | 18篇 |
专业分类
耳鼻咽喉 | 2篇 |
儿科学 | 13篇 |
妇产科学 | 2篇 |
基础医学 | 37篇 |
口腔科学 | 8篇 |
临床医学 | 53篇 |
内科学 | 102篇 |
皮肤病学 | 2篇 |
神经病学 | 7篇 |
特种医学 | 38篇 |
外科学 | 19篇 |
综合类 | 15篇 |
预防医学 | 11篇 |
药学 | 15篇 |
肿瘤学 | 17篇 |
出版年
2023年 | 2篇 |
2022年 | 4篇 |
2021年 | 10篇 |
2020年 | 2篇 |
2019年 | 5篇 |
2018年 | 6篇 |
2017年 | 3篇 |
2016年 | 4篇 |
2015年 | 5篇 |
2014年 | 9篇 |
2013年 | 7篇 |
2012年 | 4篇 |
2011年 | 8篇 |
2010年 | 10篇 |
2009年 | 11篇 |
2008年 | 14篇 |
2007年 | 24篇 |
2006年 | 11篇 |
2005年 | 11篇 |
2004年 | 7篇 |
2003年 | 6篇 |
2002年 | 6篇 |
2001年 | 4篇 |
2000年 | 5篇 |
1999年 | 6篇 |
1998年 | 16篇 |
1997年 | 16篇 |
1996年 | 19篇 |
1995年 | 10篇 |
1994年 | 19篇 |
1993年 | 4篇 |
1992年 | 1篇 |
1991年 | 4篇 |
1990年 | 8篇 |
1989年 | 15篇 |
1988年 | 8篇 |
1987年 | 4篇 |
1986年 | 4篇 |
1985年 | 5篇 |
1984年 | 3篇 |
1983年 | 4篇 |
1982年 | 1篇 |
1981年 | 5篇 |
1980年 | 5篇 |
1979年 | 1篇 |
1978年 | 1篇 |
1977年 | 1篇 |
1975年 | 1篇 |
1970年 | 1篇 |
1968年 | 1篇 |
排序方式: 共有341条查询结果,搜索用时 15 毫秒
91.
JH Sillevis Smitt JH Leusen HG Stas AH Teeuw RS Weening 《Archives of disease in childhood》1997,77(2):150-152
A 12 year old boy suffering from p67-phox deficient chronic granulomatous disease presented with a bullous skin disease and a lung infection with paecilomyces species. The histopathology of a bullous lesion showed subepidermal blister formation and microabcesses containing eosinophils in the dermal papillae. By direct immunofluorescence, linear staining of IgA at the dermal-epidermal junction was detected which confirmed the clinical diagnosis of chronic bullous disease of childhood (linear IgA dermatosis). 相似文献
92.
Biliary enteric anastomosis for relief of biliary obstruction caused by malignancy at the confluence of the bile ducts can be difficult due to non availability of an adequate length of duct for anastomosis. This paper describes an approach to the left hepatic duct to decompress the biliary tree and its successful application in 11 of 12 patients who presented with malignant hilar obstruction.KEYWORDS: Hepaticojejunostomy, Malignant biliary obstruction 相似文献
93.
94.
0 引言 在神经元上记录到的放电多数为不规则模式 ,这类节律是否服从确定性混沌规律一直是研究的热点 .混沌系统生成的奇怪吸引子包含无穷多的非稳定周期轨道 (UPOs) ,它们构成了吸引子的骨架 [1 ] .运用实验数据集的非稳定周期轨道检测 ,可辨别节律中存在的确定性和可预报性 [2 ] .我们分析大鼠坐骨神经结扎损伤模型的起步点的不规则节律 ,运用UPOs分析确认其混沌性 ,进一步分析高阶的非稳定周期轨道 .1 方法1.1 实验性起步点放电的采集 实验选择成年 SD大鼠 (体质量 15 0~ 30 0 g) ,按文献 [3]所述制备坐骨神经慢性结扎损伤动物… 相似文献
95.
Anna Berlin Gianni Zotti Sandro Zecchin Gilberto Schiavon 《Macromolecular chemistry and physics.》2002,203(9):1228-1237
Anodic coupling to polymer of some dithienylcyclopentadienes has been performed in acetonitrile. The polymers have been characterized by cyclic voltammetry, UV‐vis, MALDI mass and FT‐IR spectroscopies, and in situ conductivity. Nonsubstituted dithienylcyclopentadiene undergoes coupling both at the thiophene α‐position and at the internal cyclopentadiene sites with the production of an insoluble polymer corresponding to a tetrameric formulation. Protection of the cyclopentadiene 5 position with alkyl chains has allowed the production of regularly α‐coupled polymers. The optical gap of poly(dithienylcyclopentadiene) has been evaluated as 2.2 eV, i.e., close to that of polythiophene (2.3 eV).
96.
A Pro51Ser mutation in the COCH gene is associated with late onset autosomal dominant progressive sensorineural hearing loss with vestibular defects 总被引:14,自引:0,他引:14
de Kok YJ; Bom SJ; Brunt TM; Kemperman MH; van Beusekom E; van der Velde- Visser SD; Robertson NG; Morton CC; Huygen PL; Verhagen WI; Brunner HG; Cremers CW; Cremers FP 《Human molecular genetics》1999,8(2):361-366
We analysed a Dutch family with autosomal dominant non-syndromic
progressive sensorineural hearing loss and mapped the underlying gene
defect by genetic linkage analysis to a 11.0 cM region overlapping the
DFNA9 interval on chromosome 14q12-q13. Clinically, the Dutch family
differs from the original DFNA9 family by a later age at onset and a more
clearly established vestibular impairment. A gene that is highly and
specifically expressed in the human fetal cochlea and vestibule, COCH
(previously described as Coch5B2 ), was mapped to the DFNA9 critical
region. Sequence analysis revealed a 208C-->T mutation in the COCH gene,
resulting in a Pro51Ser substitution in the predicted protein in all
affected individuals of the family but not in unaffected family members and
200 control individuals. The same mutation was also identified in three
apparently unrelated families with a similar phenotype, suggesting the
presence of a Dutch founder mutation. The function of COCH is unknown but
several characteristics of the protein point to a structural role in the
extracellular matrix. The mutant serine at position 51 is situated between
cysteines and possibly interferes with proper COCH protein folding or its
interaction with extracellular matrix proteins.
相似文献
97.
Fatiha El Mellouli Mohamed Mouahid Alice Fusaro Bianca Zecchin Hasnae Zekhnini Abderrazak El Khantour Edoardo Giussani Elisa Palumbo Hamid Rguibi Idrissi Isabella Monne Abdelaziz Benhoussa 《Viruses》2022,14(3)
The H9N2 virus continues to spread in wild birds and poultry worldwide. At the beginning of 2016, the H9N2 Avian influenza virus (AIV) was detected in Morocco for the first time; despite the implementation of vaccination strategies to control the disease, the virus has become endemic in poultry in the country. The present study was carried out to investigate the origins, zoonotic potential, as well as the impact of vaccination on the molecular evolution of Moroccan H9N2 viruses. Twenty-eight (28) H9N2 viruses collected from 2016 to 2021 in Moroccan poultry flocks were isolated and their whole genomes sequenced. Phylogenetic and evolutionary analyses showed that Moroccan H9N2 viruses belong to the G1-like lineage and are closely related to viruses isolated in Africa and the Middle East. A high similarity among all the 2016–2017 hemagglutinin sequences was observed, while the viruses identified in 2018–2019 and 2020–2021 were separated from their 2016–2017 ancestors by long branches. Mutations in the HA protein associated with antigenic drift and increased zoonotic potential were also found. The Bayesian phylogeographic analyses revealed the Middle East as being the region where the Moroccan H9N2 virus may have originated, before spreading to the other African countries. Our study is the first comprehensive analysis of the evolutionary history of the H9N2 viruses in the country, highlighting their zoonotic potential and pointing out the importance of implementing effective monitoring systems. 相似文献
98.
Qiqi Lu Sum Leong Kristen Alexa Lee Ankur Patel Jasmine Ming Er Chua Nanda Venkatanarasimha Richard HG Lo Farah Gillan Irani Kun Da Zhuang Apoorva Gogna Pik Eu Jason Chang Hiang Keat Tan Chow Wei Too 《The British journal of radiology》2021,94(1124)
Hepatic venous pressure gradient (HVPG) is the gold-standard for measurement of portal hypertension, a common cause for life-threatening conditions such as variceal bleeding and hepatic encephalopathy. HVPG also plays a crucial role in risk stratification, treatment selection and assessment of treatment response. Thus recognition of common pitfalls and unusual hepatic venous conditions is crucial. This article aims to provide a radiographical and clinical guide to HVPG with representative clinical cases. 相似文献
99.
Controversies in transfusion medicine. Alanine aminotransferase screening of blood donors: pro 总被引:1,自引:0,他引:1
HG Klein 《Transfusion》1990,30(4):363-367
In my opinion, independent, carefully conducted scientific studies indicate that an accurate, rapid, relatively sensitive, and inexpensive laboratory test substantially reduces the major long-term risk of blood transfusion in the United States; donor ALT has emerged as one of the most effective laboratory determinants for reducing the incidence of NANB PTH. Despite its nonspecificity and limited predictive value, ALT screening may prevent up to 30 percent of cases, one-half of which would progress to chronic liver disease and then possibly to cirrhosis and hepatocellular carcinoma. Blood donors appear to understand and accept the testing rationale as a reasonable precaution. Admittedly, ALT screening is not a perfect solution. It has not been validated by prospective studies and probably never will be. Determination of the proper cutoff value remains controversial. However, the risk of PTH progresses with increasing ALT levels, so that the real issue is not whether to test, but how best to configure the test to exclude the fewest false-positive donors while detecting the most true-positive donors. It is undesirable and expensive to discard safe units of blood, but the primary responsibility of blood collectors is to ensure an adequate supply of safe components. Some still consider the ALT assay technically too demanding for routine use. However, technical concerns regarding performance and interpretation are not insurmountable, and both quality control and proficiency testing are being addressed at the national level. The assay is capable of great precision, and a system employing a national standard and single cutoff has already been described and tested with excellent results. Circumstances have changed since donor screening with ALT was widely implemented in 1986. More thorough screening and testing have eliminated many high-risk donors. Public expectations have changed as well. While it is neither reasonable nor responsible to promise the public blood transfusions without risk, neither is it prudent to propose any major change in management of the blood supply without compelling evidence that such a change will not impair transfusion safety. It is hard to defend discontinuing the ALT screen at this time, especially when the costs of retaining it are minimal and the benefits clearly greater than those of screening for HTLV-I and for Treponema pallidum (in the United States) or HIV-2 (in West Germany). A first-generation assay specific for antibody to hepatitis C will probably be available within a year.(ABSTRACT TRUNCATED AT 400 WORDS) 相似文献
100.
This paper discusses the use of bivariate survival curves estimators within the competing risk framework. Competing risks models are used for the analysis of medical data with more than one cause of death. The case of dilated cardiomiopathy is explored. Bivariate survival curves plot the conjoint mortality processes. The different graphic representation of bivariate survival analysis is the major contribute of this methodology to the competing risks analysis. 相似文献