首页 | 本学科首页   官方微博 | 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   99篇
  免费   20篇
儿科学   3篇
妇产科学   4篇
基础医学   56篇
口腔科学   6篇
临床医学   13篇
内科学   12篇
皮肤病学   1篇
神经病学   2篇
特种医学   8篇
外科学   3篇
综合类   2篇
预防医学   1篇
眼科学   2篇
药学   2篇
肿瘤学   4篇
  2018年   1篇
  2016年   1篇
  2014年   1篇
  2013年   5篇
  2012年   5篇
  2011年   1篇
  2010年   3篇
  2009年   2篇
  2008年   3篇
  2007年   4篇
  2006年   6篇
  2005年   6篇
  2004年   2篇
  2003年   1篇
  2002年   5篇
  2001年   3篇
  2000年   1篇
  1999年   2篇
  1998年   6篇
  1997年   2篇
  1996年   5篇
  1995年   7篇
  1994年   6篇
  1993年   3篇
  1992年   1篇
  1991年   2篇
  1990年   4篇
  1989年   4篇
  1988年   5篇
  1987年   2篇
  1986年   4篇
  1985年   2篇
  1982年   1篇
  1980年   1篇
  1978年   1篇
  1970年   2篇
  1969年   8篇
  1954年   1篇
排序方式: 共有119条查询结果,搜索用时 15 毫秒
1.
The most common cause of death in patients with colorectal cancer is metastatic liver disease. In order to identify patients at a high risk of developing hepatic secondaries from colorectal cancers, DNA content was measured in metastasizing colorectal primaries (Group I, n= 32) as well as in their subsequently resected liver secondaries and in sections of non-metastasizing colorectal cancers (Group II, n= 25). A modified interpretation system involving both a DNA index and percentage of cycling cells (those in S and G2 + M phases) was developed. DNA content was measured in paraffin-embedded sections by flow cytometry using internal controls (human peripheral blood mononuclear cells) and non-malignant tissue controls (19 patients with diverticular disease). In Group I there were significantly more tumours with both abnormal ploidy (aneuploid or abnormal tetraploid peak) and > 15% cycling cells compared with Group II (Chi-squared; P= 0.034). The combination of abnormal ploidy and > 15% cycling cells was superior to Dukes’ classification for identifying metastasizing tumours (Logistic Regression; P= 0.047). However, it was not possible to discriminate between the two groups using either DNA ploidy or the percentage of cycling cells alone. The metastasizing colorectal cancers exhibited similar DNA ploidy characteristics and had a similar percentage of cycling cells compared with their liver metastases. These results suggest that tumour DNA ploidy plus the percentage of cycling cells may predict the development of liver metastases and thus survival in patients with colorectal cancer.  相似文献   
2.
The results of DNA analysis are presented for a series of 90 couples, with one partner at 50% risk for Huntington's disease (HD), who were referred for exclusion testing in pregnancy over a three year period. Thirty-seven couples were studied in detail. The aims of the study were to evaluate attitudes towards prenatal testing, before pregnancy and afterwards, and the effectiveness of our counseling and methods of organising the service. Problems which could arise in relation to presymptomatic testing are documented. It is concluded that exclusion testing is a valuable form of prediction for some couples, particularly where family structure does not permit prediction for the person at risk. The need for intensive counselling was highlighted by the difficulties experienced by many couples in understanding how the test worked. Particular ethical and organisational problems may arise which require careful consideration beforehand and some recommendations are made. The proportion of couples who will continue to request exclusion testing as pre-symptomatic testing becomes more widely applicable remains unknown.  相似文献   
3.
Hereditary Non-polyposis Colon Cancer Syndrome (HNPCC) is the most common cause of familial colorectal cancer. Molecular genetic studies of HNPCC have shown evidence of locus heterogeneity, and mutations in four genes (hMSH2, hMLH1, hPMS1, and hPMS2) which encode components of the mismatch enzyme repair system may cause HNPCC. To determine the extent and nature of locus heterogeneity in HNPCC, we performed genetic linkage studies in 14 HNPCC families from eastern and north-western England. Linkage to hMLH1 was excluded in six families, each of which were likely to be linked to hMSH2 (lod score > 1.0 in each family and total lod score for all six families = 7.64). Linkage to hMSH2 was excluded in three families, each of which were likely to be linked to hMLH1 (lod score > 1.0 in each family and total lod score at hMLH1 for all three families = 3.93). In the remaining five families linkage to hMSH2 or hMLH1 could not be excluded. These results confirm locus heterogeneity in HNPCC and suggest that, in the population studied, most large families with HNPCC will have mutations in hMSH2 or hMLH1. We did not detect any correlation between clinical phenotype and the genetic linkage results, but a Muir-Torre syndrome family excluded from linkage to hMLH1 was likely to be linked to hMSH2 and showed microsatellite instability in a tumour from an affected relative.  相似文献   
4.
It was shown recently that mutations of the ATRX gene give rise to a severe, X-linked form of syndromal mental retardation associated with alpha thalassaemia (ATR-X syndrome). In this study, we have characterised the full-length cDNA and predicted structure of the ATRX protein. Comparative analysis shows that it is an entirely new member of the SNF2 subgroup of a superfamily of proteins with similar ATPase and helicase domains. ATRX probably acts as a regulator of gene expression. Definition of its genomic structure enabled us to identify four novel splicing defects by screening 52 affected individuals. Correlation between these and previously identified mutations with variations in the ATR-X phenotype provides insights into the pathophysiology of this disease and the normal role of the ATRX protein in vivo.   相似文献   
5.
Microcephaly with or without chorioretinopathy, lymphoedema, or mental retardation (MCLMR) (MIM No.152950) is a rare autosomal dominant condition for which a causative gene has recently been identified. Mutations in the kinesin family member 11 (KIF11) gene have now been described in 16 families worldwide. This is a review of the condition based on the clinical features of 37 individuals from 22 families. This report includes nine previously unreported families and additional information for some of those reported previously. The condition arose de novo in 8/20 families (40%). The parental results were not available for two probands. The mutations were varied and include missense, nonsense, frameshift, and splice site and are distributed evenly throughout the KIF11 gene. In our cohort, 86% had microcephaly, 78% had an ocular abnormality consistent with the diagnosis, 46% had lymphoedema, 73% had mild-moderate learning difficulties, 8% had epilepsy, and 8% had a cardiac anomaly. We identified three individuals with KIF11 mutations but no clinical features of MCLMR demonstrating reduced penetrance. The variable expression of the phenotype and the presence of mildly affected individuals indicates that the prevalence may be higher than expected, and we would therefore recommend a low threshold for genetic testing.  相似文献   
6.
The clinical course of acute pancreatitis is variable. Severe pancreatitis is observed in up to 20% of cases and is associated with high mortality rates of up to 40%. The most serious complication is the infection of the (peri-)pancreatic necroses. The therapeutic goal is debridement of the infected material. Whereas surgical methods still represent the gold standard, minimally invasive interventional approaches are gaining importance. This article reviews the different interventional procedures, particularly percutaneous, CT-guided drainage and necrosectomy. Furthermore, an overview of published studies about interventional therapy in patients with acute necrotizing pancreatitis is given.  相似文献   
7.
OBJECTIVE—Early research into Wolf-Hirschhorn syndrome (WHS) described a high mortality and no relationship between deletion size and phenotype. This may need to be revised in the light of improved cytogenetic resolution and medical care. We have collected epidemiological data to allow the calculation of birth incidence and mortality figures. In addition, we have investigated the possibility of a relationship between deletion size and mortality.
METHOD—Information relating to past and present cases diagnosed in the UK was collected by multiple ascertainment.
RESULTS—A total of 159 cases were collected. The status (alive or dead) was determined for 146, of whom 96 are alive, 37 had died, and 13 were detected on prenatal diagnostic tests. A minimum birth incidence of 1 in 95 896 was calculated. The crude infant mortality rate was 17% (23/132) and in the first two years of life the mortality rate was 21% (28/132). Cases with large de novo deletions (proximal to and including p15.2) were more likely to have died than those with smaller deletions (odds ratio=5.7, 95% CI=1.7-19.9) after adjusting for age. A comparison of survival curves for de novo deletions and translocations did not show a statistically significant difference (p=0.11). The median survival time for de novo deletions was 34+ years while for translocation cases it was 18+ years.
CONCLUSIONS—The mortality rate is lower than previously reported. There is a statistically significant relationship between deletion size and overall risk of death in de novo deletion cases. The difference in survival curves between de novo deletions and translocations is not statistically significant.


Keywords: Wolf-Hirschhorn syndrome; chromosome 4; mortality  相似文献   
8.
The aim of this study was to determine whether an inequality in caries experience existed for permanent teeth between Asian and white primary 7 schoolchildren (mean age 10.59 years, SE 0.03 years) attending Greater Glasgow schools. In 1989, all 18 schools in Greater Glasgow with at least 25% of its pupils from an Asian background participated in the study. All the schools selected by this method were located in areas of multiple deprivation according to both the ACORN neighbourhood classification and the Jarman social deprivation score. Five hundred and sixteen children were examined. The Asian population as a whole (n = 241, DMFT = 0.95) and each of the subgroups, Muslim with English-speaking mothers (ES) (n = 67, DMFT = 1.24), and non-English-speaking mothers (NES) (n = 130, DMFT = 0.93), non-Muslim with ES mothers (n = 24, DMFT = 0.38) and NES mothers (n = 20, DMFT = 0.90), had a better caries experience of the first permanent molar than that of the white indigenous population (n = 242, DMFT = 1.52). This trend was also seen in the percentage of children with sound first permanent molars: white = 39%, Asian (total) = 54%, Muslim (ES) = 43% and (NES) = 56%, non-Muslim (ES) = 71% and (NES) = 60%. It is concluded that the inequality in caries experience reported in the primary dentition between young Asian and indigenous schoolchildren is not apparent for permanent teeth in children attending primary 7 classes in multiracial schools.  相似文献   
9.
A microcomputer program has been designed to maintain a large data base for Huntington disease. This program facilitates such data manipulation as adding, altering, retrieving, deleting, and printing pedigrees. The program is self-contained and has a risk-calculating routine built in which automatically provides both the Mendelian and age-modified risks. This package is capable of printing the pedigrees on a simple printer or, alternatively, creates an output-file which can be used with a dedicated plotting program for drawing the pedigrees and their data on a plotter. The program has a routine which can provide a series of statistical data from the register including age-of-onset, diagnosis, death, and other useful information.  相似文献   
10.
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