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   562篇
  免费   20篇
耳鼻咽喉   19篇
儿科学   19篇
妇产科学   6篇
基础医学   67篇
口腔科学   48篇
临床医学   23篇
内科学   165篇
皮肤病学   2篇
神经病学   12篇
特种医学   19篇
外科学   85篇
综合类   1篇
预防医学   26篇
眼科学   6篇
药学   38篇
肿瘤学   46篇
  2023年   5篇
  2022年   9篇
  2021年   14篇
  2020年   7篇
  2019年   8篇
  2018年   9篇
  2017年   6篇
  2016年   8篇
  2015年   10篇
  2014年   17篇
  2013年   15篇
  2012年   23篇
  2011年   25篇
  2010年   22篇
  2009年   20篇
  2008年   31篇
  2007年   34篇
  2006年   41篇
  2005年   18篇
  2004年   17篇
  2003年   19篇
  2002年   15篇
  2001年   12篇
  2000年   18篇
  1999年   13篇
  1998年   3篇
  1997年   7篇
  1996年   4篇
  1992年   8篇
  1991年   9篇
  1990年   7篇
  1989年   18篇
  1988年   10篇
  1987年   6篇
  1986年   7篇
  1985年   8篇
  1984年   5篇
  1983年   8篇
  1982年   6篇
  1980年   4篇
  1979年   7篇
  1978年   3篇
  1977年   5篇
  1976年   6篇
  1975年   8篇
  1974年   3篇
  1970年   3篇
  1968年   4篇
  1967年   4篇
  1965年   2篇
排序方式: 共有582条查询结果,搜索用时 31 毫秒
1.
2.
CENP-A, a centromere-specific histone H3, is conserved throughout eukaryotes, and formation of CENP-A chromatin defines the active centromere region. Here, we report the isolation of CENP-A chromatin from HeLa interphase nuclei by chromatin immunoprecipitation using anti-CENP-A monoclonal antibody, and systematic identification of its components by mass spectrometric analyses. The isolated chromatin contained CENP-B, CENP-C, CENP-H, CENP-I/hMis 6 and hMis 12 as well as CENP-A, suggesting that the isolated chromatin may represent the centromere complex (CEN-complex). Mass spectrometric analyses of the CEN-complex identified approximately 40 proteins, including the previously reported centromere proteins and the proteins of unknown function. In addition, we unexpectedly identified a series of proteins previously reported to be related to functions other than chromosome segregation, such as uvDDB-1, XAP8, hSNF2H, FACTp180, FACTp80/SSRP1, polycomb group proteins (BMI-1, RING1, RNF2, HPC3 and PHP2), KNL5 and racGAP. We found that uvDDB-1 was actually localized to the centromeric region throughout cell cycle, while BMI-1 was transiently co-localized with the centromeres in interphase. These results give us new insights into the architecture, dynamics and function of centromeric chromatin in interphase nuclei, which might reflect regulation of cell proliferation and differentiation.  相似文献   
3.
4.
A long-standing assumption in molecular biology posits that the conservation of protein and nucleic acid sequences emphasizes the functional significance of biomolecules. These conserved sequences fold into distinct secondary and tertiary structures, enable highly specific molecular interactions, and regulate complex yet organized molecular processes within living cells. However, recent evidence suggests that biomolecules can also function through primary sequence regions that lack conservation across species or gene families. These regions typically do not form rigid structures, and their inherent flexibility is critical for their functional roles. This review examines the emerging roles and molecular mechanisms of “nondomain biomolecules,” whose functions are not easily predicted due to the absence of conserved functional domains. We propose the hypothesis that both domain- and nondomain-type molecules work together to enable flexible and efficient molecular processes within the highly crowded intracellular environment.  相似文献   
5.
6.
Prostaglandin E1-induced hypotension (25% reduction from the preadministration level in mean arterial pressure) was applied to thirteen patients. Eight patients among them were operated in the supine position (group I) and other five in the prone position (group II). The maintenance dose of PGE1 was considerably lower in group II than in group I (0.067µg·kg–1·min–1 vs. 0.119µg·kg–1·min–1). In group I, there was a significant increase in CI, with a significant decrease in SVRI and PVRI during PGE1-induced hypotension. Such a high dose of PGE1 (0.119µg·kg–1·min–1) was considered to have a direct dilating action on the systemic resistance bed as well as on the pulmonary vasculature. It was considered that the suppression of hypoxic pulmonary vasoconstriction could be a mechanism to increase venous admixture during PGE1-induced hypotension. In group II, there was no significant increase in CI, and no significant decrease in SVRI and PVRI. PGE1-induced hypotension can be safely applied to the anesthetized patients, but we should be careful to apply it to the patients in the prone position, because lower dose of PGE1 can induce severe hypotension, which is not accompanied by the increase in CI as occures in the patients in the supine position.(Hirose M, Yoda K, Sakai K, et al.: Comparative Study on the cardio-respiratory change during prostaglandin E1-induced hypotention in the patients in the supine and prone position. J Anesth 5: 30–35, 1991)  相似文献   
7.
8.

Objectives

To investigate the association of serum lipids and high-sensitivity C-reactive protein (hs-CRP) with obesity in school children and to explore whether hs-CRP levels could be used to predict the presence or absence of obesity 12 months later.

Methods

The subjects were school children (6–11 years old) in Japan. Blood sampling and physical measurements were performed in school (2001); low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), triglycerides, and hs-CRP levels were measured. Data from children who could be followed 12 months later were analyzed. Subjects weighing 20 % or more over his/her standard weight were regarded as obese, and the association of obesity with serum parameters was analyzed.

Results

Data from 612 subjects were analyzed (follow-up rate, 75.4 %). The mean of each serum parameter was significantly higher (inverse for HDL-C; lower) in obese than that in non-obese children. Logistic regression analysis for obesity at baseline showed that the odds ratio (OR) of hs-CRP was the highest [OR, 2.15; 95 % confidence interval (CI), 1.65–2.78 for an interquartile rage (IQR) increase]; the association with triglycerides and LDL-C/HDL-C was significant. At the 12-month follow-up, the OR of high hs-CRP remained the highest of all serum parameters (2.09; 95 % CI, 1.63–2.69 for an IQR increase).

Conclusions

High levels of triglycerides, LDL-C/HDL-C, and hs-CRP increased the risk of obesity in school children. Hs-CRP is considered to be a better predictor of obesity 12 months later than is LDL-C/HDL-C.  相似文献   
9.
Background: Background: Few studies have investigated the association between smoking and ultrasonographically diagnosed gallbladder (GB) disease, and their results were uncertain. This study was conducted to examine the association between smoking and drinking and GB diseases. Methods: A total of 9947 subjects (age, 30–69 years; 4953 men and 4994 women) voluntarily received a paid medical check-up at our center in Yamanashi Prefecture in Japan. All of the subjects underwent abdominal ultrasonographic (US) examination, a demographic check, and a biochemical test, and answered a self-administered questionnaire asking about smoking habits and alcohol consumption. Of the 9947 subjects, 483 had gallstones, 819 had gallbladder polyps, and 169 were in a state of postcholecystectomy. We compared the findings in this group with the findings in 8417 people (4144 males and 4273 females) with normal gallbladder. Results: Multiple regression analysis among males showed that cigarette smoking was inversely related to GB polyps (odds ratio, [OR], 0.76; 95% confidence internal [CI], 0.59–0.98 and OR, 0.74; 95% CI, 0.56–0.98, respectively, for current and ex-smokers). Ex-smokers a showed positive association with the postcholecystectomy state (OR, 2.56; 95% CI, 1.18–5.52). Light drinkers showed an inverse relation to GB stones (OR, 0.69; 95% CI, 0.49–0.99), and heavy drinkers showed an inverse relation to GB polyps (OR, 0.68; 95% CI, 0.51–0.90). Current drinkers showed an inverse relation to the postcholecystectomy state (OR, 0.48; 95% CI, 0.28–0.83). Conclusions: Cigarette smoking was inversely related to gallbladder polyps in males and was positively related to the postcholecystectomy state. Drinking was inversely related to gallstones, GB polyps, and the postcholecystectomy state in males. Received: July 19, 2001 / Accepted: November 2, 2001  相似文献   
10.
Frozen shoulder is a relatively common disorder that leads to severe pain and stiffness in the shoulder joint. Although this disorder is self‐limiting in nature, the symptoms often persist for years, resulting in severe disability. Recent studies using human specimens and animal models have shown distinct changes in the gene expression patterns in frozen shoulder tissue, indicating that novel therapeutic intervention could be achieved by controlling the genes that are potentially involved in the development of frozen shoulder. To achieve this goal, it is imperative to develop a reliable animal joint contracture model in which gene expression can be manipulated by gene targeting and transgenic technologies. Here, we describe a novel shoulder contracture mouse model. We found that this model mimics the clinical presentation of human frozen shoulder and recapitulates the changes in the gene expression pattern and the histology of frozen shoulder and joint contracture in humans and other larger animal models. The model is highly reproducible, without any major complications. Therefore, the present model may serve as a useful tool for investigating frozen shoulder etiology and for identifying its potential target genes. © 2015 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 33:1732–1738, 2015.  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