首页 | 官方网站   微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   319篇
  免费   30篇
医药卫生   349篇
  2021年   3篇
  2020年   5篇
  2019年   3篇
  2018年   3篇
  2017年   2篇
  2015年   5篇
  2014年   3篇
  2013年   6篇
  2012年   16篇
  2011年   13篇
  2010年   2篇
  2009年   5篇
  2008年   7篇
  2007年   8篇
  2006年   14篇
  2005年   10篇
  2004年   8篇
  2003年   11篇
  2002年   12篇
  2001年   9篇
  2000年   12篇
  1999年   22篇
  1998年   7篇
  1997年   4篇
  1996年   3篇
  1995年   7篇
  1994年   4篇
  1993年   4篇
  1992年   18篇
  1991年   14篇
  1990年   14篇
  1989年   9篇
  1988年   13篇
  1987年   8篇
  1986年   7篇
  1985年   3篇
  1984年   12篇
  1983年   7篇
  1982年   4篇
  1981年   3篇
  1980年   4篇
  1979年   7篇
  1978年   5篇
  1977年   2篇
  1975年   2篇
  1974年   2篇
  1972年   1篇
  1971年   1篇
  1970年   2篇
  1967年   1篇
排序方式: 共有349条查询结果,搜索用时 406 毫秒
1.
In a previous article we reported that mutations favoring cancer at adulthood seemed to improve fertility and limit miscarriages. Because spontaneous abortion may result from anomalies in embryo, we questioned if an increased frequency of congenital malformation could be evidenced among cancer-prone families. Oncogenetics database (≈193 000 members) of the comprehensive cancer center Jean Perrin was crossed with regional registry of congenital malformations (≈10 000). Among children born between 1986 and 2011, 176 children with malformation matched in both databases. In breast/ovaries cancer-prone families, the risk for malformations was multiplied by 2.4 [1.2-4.5] in case of a BRCA1 mutation. Frequencies of malformation in BRCA2 and MMR mutated families were similar to families without a cancer syndrome. In comparison to malformations concerning a unique anatomical system, multimalformations were significantly more frequent in case of BRCA or MMR mutations: compared to families without cancer syndrome, the risk of multimalformations was multiplied by 4.1 [0.8-21.7] for cancer-prone families but with no known deleterious mutation, by 6.9 [1.2-38.6] in families with a known mutation but an unknown parental mutational status and by 10.4 [2.3-46.0] when one parent carried the familial mutation. No association with the type of anatomical system was found, nor with multiple births. These results suggest that BRCA and MMR genes play an important role in human embryogenesis and that if their function is lowered because of heterozygote mutations, congenital malformations are either more likely (BRCA1 mutations) and/or more susceptible to concern several anatomical systems.  相似文献   
2.
3.
We examined the prevalence of cytomegalovirus infectious episodes, as defined by clinical, virological, and serological criteria (i.e., CMV disease), in 660 kidney graft recipients; 109 patients (16.5%) developed the disease, and 551 did not. No significant statistical link between CMV disease prevalence and a given HLA-A, -B, or -DR allele was observed. However, patients with HLA-DR7 matched grafts were statistically more frequently found (P < 0.01) in the group of recipients who developed CMV disease as compared with the group who did not develop CMV disease. Furthermore, among patients who developed CMV disease, a significant increase of HLA-DR7 matched over DR7 mismatched patients was noted, whereas no difference between matched and mismatched recipients for the other HLA-DR alleles was found. No difference in the severity of graft failure, often observed during, or immediately after, the CMV episode, was noted between patients matched or mismatched for HLA-DR7. Our data suggest that donor/recipient matching for HLA-DR7 is associated with increased CMV disease.  相似文献   
4.
Due to some limitations of restriction fragment length polymorphism (RFLP) analysis in HLA-DR-DQ typing, we present a combined use of RFLP and polymerase chain reaction (PCR)-allele-specific oligonucleotide (ASO) typing. This scheme consists in selectively amplifying the few RFLP ill-defined genes (DR1/DR'Br' and DR4-Dw subsets) using PCR with allele specific primers to avoid cross-hybridization.  相似文献   
5.
6.
7.
It is recognized that bronchoalveolar lavage (BAL) gives access to particulate matter present at the surface of the peripheral airspace. The objective of the present study was to evaluate the ability of BAL fluid analysis to predict the lung parenchymal particulate content. A BAL fluid sample, the parenchyma sample having undergone BAL, and an adjacent parenchyma sample that had not undergone BAL were obtained at autopsy on 10 individuals without any known recent occupational exposure to mineral particles. The particles (larger than 0.1 micron) were analyzed using a transmission electron microscope equipped with a microanalysis system. Nineteen types of particles were distinguished. The distribution of particle types in the three samples was compared. No significant difference between the relative concentrations was found, except for two particle types: fly ash (excess in BAL fluid compared with lavaged lung) and kaolinite (excess in lavaged lung compared with adjacent area). Such differences may be due to limitations in methodology. Although no correlation could be found between the absolute concentrations of particles in BAL fluid and in lung tissue, analysis of particles in BAL fluid may provide information on the types of particles present in the lung parenchyma.  相似文献   
8.
The applications of molecular biology diagnosis in oncology are presented and discussed. These are: improved nosologic definition; diagnosis of clonality; definition of new prognosis subgroups in some cancers; as an aid in bone marrow transplantation follow-up; diagnosis of the residual disease; early diagnosis of cancer; evaluation of individual cancer risk.  相似文献   
9.
Hereditary pancreatitis (HP) is a rare inherited disorder, characterised by recurrent episodes of pancreatitis often beginning in early childhood. The mode of inheritance suggests an autosomal dominant trait with incomplete penetrance. The gene, or at least one of the genes, responsible for hereditary pancreatitis has been mapped to the long arm of chromosome 7 and a missense mutation, an arginine to histidine substitution at residue 117 in the trypsinogen cationic gene (try4) has been shown to segregate with the HP phenotype. The aim of this work was to investigate the molecular basis of hereditary pancreatitis. This study was performed on 14 HP families. The five exons of the trypsinogen cationic gene were studied using a specific gene amplification assay combined with denaturing gradient gel electrophoresis (DGGE). The present paper describes three novel mutations, namely K23R and N29I and a deletion -28delTCC in the promoter region. We also found a polymorphism in exon 4, D162D. In eight of these families we found a mutation which segregates with the disease. A segregation analysis using microsatellite markers carried out on the other families suggests genetic heterogeneity in at least one of them. Our findings confirm the implication of the cationic trypsinogen gene in HP and highlight allelic diversity associated with this phenotype. We also show that the pattern of inheritance of HP is probably complex and that other genes may be involved in this genetic disease.  相似文献   
10.
The aim of this study was to determine, by transmission electron microscopy, the differentiation features of 21 human malignant mesothelioma cell lines (HMCLs) established from 13 specimens of 12 confirmed human malignant mesotheliomas, and of tumours induced in nude mice injected with 16 HMCLs. Fifty per cent of HMCLs showed typical mesothelial differentiation (long and slender microvilli, desmosomes, perinuclear intermediate filaments); 29 per cent did not show differentiation; and the remainder were poorly differentiated. Three human tumour specimens gave several different HMCLs; the cell lines obtained from a given tumour exhibited variable mesothelial differentiation. Eleven HMCLs were compared with the native tumour. Four were similar to the tumour and seven were less well differentiated, in most cases in relation to their microvilli. With six HMCLs, tumours induced in nude mice were less well differentiated than the corresponding cell lines, whereas with four HMCLs, tumours were equally or better differentiated. However, in most nude mice tumours, typical mesothelial microvilli were present. These results show that cell lines established from malignant mesothelioma may exhibit dedifferentiated features. However, while the variability in ultrastructural differentiation may result from the culture microenvironment, it could also be related to the state of differentiation, of the native tumour sample and to tumour cell heterogeneity.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司    京ICP备09084417号-23

京公网安备 11010802026262号