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   23篇
  免费   2篇
  25篇
  2022年   1篇
  2020年   1篇
  2019年   2篇
  2018年   3篇
  2016年   1篇
  2015年   3篇
  2014年   3篇
  2013年   2篇
  2012年   1篇
  2011年   1篇
  2010年   2篇
  2008年   1篇
  2007年   1篇
  2003年   1篇
  1985年   1篇
  1979年   1篇
排序方式: 共有25条查询结果,搜索用时 15 毫秒
11.
12.
Public attitudes to family medicine in Turkey have lagged behind its rapid academic development. The effect of undergraduate training in primary care on medical students' attitudes to family medicine has not been assessed. Objectives of this study were to assess the attitudes of first year medical students at Uludag University School of Medicine in Bursa, Turkey to family medicine and to determine their career aspirations. The study was a survey of the first year medical class in 2003-2004. The response rate was 95% (248/261 students). Students were positive about their choice of medicine as a career but had negative opinions of general practice. Female students were more positive in this respect. Initial preference was for specialization in fields other than general practice with little knowledge of the academic specialty of family medicine. Greater undergraduate exposure to family medicine is needed in order to increase knowledge of the field and influence student career choices.  相似文献   
13.
BackgroundApart from blood pressure level itself, variation in blood pressure has been implicated in the development of stroke in subgroups at high cardiovascular risk. We determined the association between visit-to-visit blood pressure variability and stroke risk in the general population, taking into account the size and direction of variation and several time intervals prior to stroke diagnosis.Methods and findingsFrom 1990 to 2016, we included 9,958 stroke-free participants of the population-based Rotterdam Study in the Netherlands. This is a prospective cohort study including participants aged 45 years and older. Systolic blood pressure (SBP) variability was calculated as absolute SBP difference divided by mean SBP over 2 sequential visits (median 4.6 years apart). Directional SBP variability was defined as SBP difference over 2 visits divided by mean SBP. Using time-varying Cox proportional hazards models adjusted for age, sex, mean SBP, and cardiovascular risk factors, hazard ratios (HRs) for stroke up to January 2016 were estimated per SD increase and in tertiles of variability. We also conducted analyses with 3-, 6-, and 9-year intervals between variability measurement and stroke assessment. These analyses were repeated for diastolic blood pressure (DBP). The mean age of the study population was 67.4 ± 8.2 years and 5,776 (58.0%) were women. During a median follow-up of 10.1 years, 971 (9.8%) participants had a stroke, including 641 ischemic, 89 hemorrhagic, and 241 unspecified strokes. SBP variability was associated with an increased risk of hemorrhagic stroke (HR per SD 1.27, 95% CI 1.05–1.54, p = 0.02) and unspecified stroke (HR per SD 1.21, 95% CI 1.09–1.34, p < 0.001). The associations were stronger for all stroke subtypes with longer time intervals; the HR for any stroke was 1.29 (95% CI 1.21–1.36, p < 0.001) at 3 years, 1.47 (95% CI 1.35–1.59, p < 0.001) at 6 years, and 1.38 (95%CI 1.24–1.51, p < 0.001) at 9 years. For DBP variability, we found an association with unspecified stroke risk. Both the rise and fall of SBP and the fall of DBP were associated with an increased risk for unspecified stroke. Limitations of the study include that, due to an average interval of 4 years between visits, our findings may not be generalizable to blood pressure variability over shorter periods.ConclusionsIn this population-based study, we found that visit-to-visit blood pressure variation was associated with an increased risk of unspecified and hemorrhagic stroke, independent of direction of variation or mean blood pressure.

In a population-based cohort study, Alis Heshmatollah and colleagues investigate the associations between blood pressure variability and risk of stroke among adults in the Netherlands.  相似文献   
14.
A taxonomic study was carried out on eight strains of Saccharomyces boulardii. Morphological and physiological characteristics were consistent with those of Saccharomyces cerevisiae. Sequences of the D1/D2 domain of the 26S rDNA were identical for all strains examined and had a similarity value of 100% compared to sequences of the type strain of S. cerevisiae (CBS 1171T) and strain S288c. For all S. boulardii isolates was found the exact same ITS1-5.8S rDNA-ITS2 sequence, which displayed a close resemblance with the sequences published for S288c (99.9%), CBS 1171(T) (99.3%) and other S. cerevisiae strains. Sequence analysis of the mitochondrial cytochrome-c oxidase II gene (COX2) also resulted in identical sequences for the S. boulardii isolates and comparisons with available nucleotide sequences revealed close relatedness to strains of S. cerevisiae including S288c (99.5%) and CBS 1171(T) (96.6%). The electrophoretic karyotypes of the S. boulardii strains appeared quite uniform and although very typical of S. cerevisiae, they formed a cluster separate from strains of this species. The results of the present study strongly indicate a close relatedness of S. boulardii to S. cerevisiae and thereby support the recognition of S. boulardii as a member of S. cerevisiae and not as a separate species.  相似文献   
15.
The increasing usage of social media for conversations, together with the availability of its data to researchers, provides an opportunity to study human conversations on a large scale. Twitter, which allows its users to post messages of up to a limit of 140 characters, is one such social media. Previous studies of utterances in books, movies and Twitter have shown that most of these utterances, when transcribed, are much shorter than 140 characters. Furthermore, the median length of Twitter messages was found to vary across US states. Here, we investigate whether the length of Twitter messages varies across different regions in the UK. We find that the median message length, depending on grouping, can differ by up to 2 characters.  相似文献   
16.
17.
18.
Mitochondrial‐derived peptides (MDP) are encoded by functional short open reading frames in the mitochondrial DNA (mtDNA). These include humanin, and the recently discovered mitochondrial open reading frame of the 12S rRNA‐c (MOTS‐c). Although more research is needed, we suggest that the m.1382A>C polymorphism located in the MOTS‐c encoding mtDNA, which is specific for the Northeast Asian population, may be among the putative biological mechanisms explaining the high longevity of Japanese people.  相似文献   
19.
20.
A halotolerant bacterium capable of chitinase production was previously isolated from saline soils of Gavkhooni marsh, Iran. The strain was identified as Bacillus pumilus strain SG2. This strain secretes two chitinases into the medium in response to the presence of chitin in the medium. The two chitinases, ChiS and ChiL, were active on both polymeric as well as oligosaccharide substrates. In this study, these two extracellular chitinases were purified from the supernatant of the Bacillus culture by ammonium sulfate precipitation. The optimum pH and temperature for both of these chitinases were pH 6 and 37°C, respectively. According to the conserved domain analysis, ChiS and ChiL were categorized in family 18 of the glycosylhydrolases. Three essential conserved amino acid residues (Asp-194, Asp-196 and Glu-198) in ChiS and (Asp-228, Asp-230 and Glu-232) in ChiL were found within the active site. Antifungal activities of the two purified chitinases were assessed on Rhizoctonia solani, Verticillium sp., Nigrospora sp., Stemphyllium botryosum and Bipolaris sp. demonstrating inhibition of all the tested strains. However, these chitinases did not inhibit cell wall formation of the non-chitin-containing fungi (oomycetes) Phytophthora citricola and Phytophthora capsici. This is the first investigation demonstrating antifungal activity of chitinases purified from B. pumilus SG2.  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