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   365篇
  免费   56篇
  国内免费   14篇
耳鼻咽喉   3篇
儿科学   14篇
妇产科学   7篇
基础医学   105篇
口腔科学   5篇
临床医学   57篇
内科学   70篇
皮肤病学   6篇
神经病学   4篇
特种医学   80篇
外科学   26篇
综合类   2篇
预防医学   16篇
眼科学   5篇
药学   18篇
中国医学   1篇
肿瘤学   16篇
  2021年   5篇
  2020年   2篇
  2019年   5篇
  2018年   2篇
  2017年   7篇
  2016年   3篇
  2015年   3篇
  2014年   5篇
  2013年   10篇
  2012年   6篇
  2011年   10篇
  2010年   9篇
  2009年   9篇
  2008年   9篇
  2007年   17篇
  2006年   12篇
  2005年   19篇
  2004年   11篇
  2003年   18篇
  2002年   12篇
  2001年   16篇
  2000年   10篇
  1999年   10篇
  1998年   23篇
  1997年   20篇
  1996年   17篇
  1995年   14篇
  1994年   11篇
  1993年   10篇
  1990年   4篇
  1989年   14篇
  1988年   22篇
  1987年   9篇
  1986年   9篇
  1985年   4篇
  1984年   6篇
  1983年   4篇
  1982年   12篇
  1981年   5篇
  1980年   6篇
  1979年   4篇
  1978年   3篇
  1977年   8篇
  1976年   6篇
  1975年   5篇
  1971年   2篇
  1970年   2篇
  1969年   1篇
  1968年   1篇
  1965年   1篇
排序方式: 共有435条查询结果,搜索用时 15 毫秒
61.
Dewald  GW; Pierre  RV; Phyliky  RL 《Blood》1982,59(1):100-105
Structural abnormalities of the X chromosome are rarely found in neoplastic disorders. We describe three patients with a history of idiopathic acquired sideroblastic anemia (IASA); each one had an abnormal clone of cells in the bone marrow, characterized by a structurally abnormal X chromosome. In two of these patients, the predominant karyotype was 47,X,2idic(X)(q13); in the other patient, it was 46,X,t(X;11)(q13;p15). Inasmuch as all three of these cases involved chromosome band Xq13, as did two previously published cases, we suggest that band Xq13 may be more prone to structural rearrangement than other X chromosome bands in hematologic disorders. The common Xq13 chromosome breakpoint and clinical presentation (IASA) among these three patients and the occurrence of an X-linked type of sideroblastic anemia may suggest that an association exists between X chromosome abnormalities and IASA. Perhaps alteration of a gene or chromosome structure in or near band Xq13 predisposes to development of IASA. The fact that two of these patients had preleukemia and the third had overt acute leukemia may imply that patients with IASA and X chromosome abnormalities have a poor prognosis. Cases of IASA without associated X chromosome abnormalities are known; thus, if an association between IASA and an abnormal X chromosome does exist, most likely it involves only some patients with IASA.  相似文献   
62.
63.
Recently published clinical trial data have produced compelling evidence for increased survival when Herceptin is administered to patients whose tumors are HER2 amplified. Therefore, the accuracy of HER2 status is essential to determine which patients should or should not receive Herceptin. Although HER2 results obtained by FISH and IHC are often in agreement, there is a persistent group of cases in which results are discordant, particularly among tumors with intermediate results. A multivariable analysis was undertaken to determine relative significance of various clinical and pathologic findings for patients diagnosed with infiltrating ductal carcinoma, and a data model was produced that predicts which patients are most likely to have HER2 amplified tumors. Correlates of HER2 amplification were higher Scarff-Bloom-Richardson grade, younger age at diagnosis, and a comedo ductal carcinoma in situ component.  相似文献   
64.
We report a case of a culture-negative osteomyelitis in which our newly developed real-time polymerase chain reaction (PCR) could differentiate Staphylococcus aureus from Staphylococcus epidermidis. This is the first report that described the application of this novel assay to an orthopedics clinical sample. This assay may be useful for other clinical culture-negative cases in a combination with a broad-spectrum assay as a rapid microorganism identification method.  相似文献   
65.
66.
67.

Background  

Quality of care from the perspective of users is increasingly used in evaluating health care performance. Going beyond satisfaction studies, quality of care from the users' perspective is conceptualised in two dimensions: the importance users attach to aspects of care and their actual experience with these aspects. It is well established that health care systems differ in performance. The question in this article is whether there are also differences in what people in different health care systems view as important aspects of health care quality. The aim is to describe and explain international differences in the importance that health care users attach to different aspects of health care.  相似文献   
68.
张辉  尹宗生  张胜权  陈斌  王伟  华兴一  胡勇  李光武 《医学争鸣》2005,26(22):F0002-F0002
1 材料和方法 1.1 材料 KM小鼠,孕13.5 d,安徽省实验动物中心提供. 大肠杆菌JM109由安徽医科大学分子生物学教研室提供. Trizol试剂盒、pSecTag2/Hygro B质粒(Invitrogen). 质粒小量提取试剂盒、 RT-PCR试剂盒(Promega);Ex Taq DNA聚合酶、T4 DNA连接酶,DNA Marker, pMD18-T Vector,限制性内切酶(TaKaRa).  相似文献   
69.
Salmonella and Shigella species are routinely sought in stool specimens submitted for culture. It is a common practice to screen lactose-negative colonies by using triple sugar iron agar, lysine iron agar, and Christensen urea agar to determine if further identification is necessary. We designed and evaluated a novel combination of media, which are layered in a single tube, for screening isolates suspected to possibly represent Salmonella or Shigella. We tested this media combination with 106 Salmonella, 56 Shigella, and 56 other gram-negative bacilli.All Salmonella and Shigella isolates tested were appropriately characterized as possible Salmonella or Shigella by using an algorithm developed for use with this media combination. Similarly, 53 (95%) of 56 other gram-negative bacilli were appropriately screened as non -Salmonella and non -Shigella isolates. This unique media combination provides the most important biochemical reactions needed to screen for Salmonella and Shigella in a single-tube format, which decreases labor by two thirds (ie, 1 tube is inoculated vs 3).  相似文献   
70.
We compared the relative levels of effectiveness of three commercial identification kits and three nucleic acid amplification tests for the identification of coryneform bacteria by testing 50 diverse isolates, including 12 well-characterized control strains and 38 organisms obtained from pediatric oncology patients at our institution. Between 33.3 and 75.0% of control strains were correctly identified to the species level by phenotypic systems or nucleic acid amplification assays. The most sensitive tests were the API Coryne system and amplification and sequencing of the 16S rRNA gene using primers optimized for coryneform bacteria, which correctly identified 9 of 12 control isolates to the species level, and all strains with a high-confidence call were correctly identified. Organisms not correctly identified were species not included in the test kit databases or not producing a pattern of reactions included in kit databases or which could not be differentiated among several genospecies based on reaction patterns. Nucleic acid amplification assays had limited abilities to identify some bacteria to the species level, and comparison of sequence homologies was complicated by the inclusion of allele sequences obtained from uncultivated and uncharacterized strains in databases. The utility of rpoB genotyping was limited by the small number of representative gene sequences that are currently available for comparison. The correlation between identifications produced by different classification systems was poor, particularly for clinical isolates.  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