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   177篇
  免费   11篇
  国内免费   1篇
儿科学   3篇
妇产科学   3篇
基础医学   23篇
口腔科学   2篇
临床医学   17篇
内科学   42篇
皮肤病学   2篇
神经病学   15篇
特种医学   6篇
外科学   31篇
预防医学   11篇
眼科学   17篇
药学   15篇
肿瘤学   2篇
  2023年   2篇
  2022年   5篇
  2021年   14篇
  2020年   6篇
  2019年   5篇
  2018年   7篇
  2017年   9篇
  2016年   4篇
  2015年   4篇
  2014年   5篇
  2013年   7篇
  2012年   13篇
  2011年   18篇
  2010年   9篇
  2009年   7篇
  2008年   5篇
  2007年   7篇
  2006年   8篇
  2005年   15篇
  2004年   9篇
  2003年   12篇
  2002年   10篇
  2001年   1篇
  1999年   1篇
  1997年   1篇
  1996年   1篇
  1991年   1篇
  1981年   1篇
  1976年   2篇
排序方式: 共有189条查询结果,搜索用时 31 毫秒
1.
2.
This assessment provides the most recent estimates of overweight and obesity among children 4 to 5 years old who were enrolled in public schools in the 2007–2008 school year, using data obtained from Student Health Records for 12,823 children, which represents 91% of the 14,070 children who were enrolled in kindergarten in 2007–2008. This assessment is a census of 4 to 5 year olds that entered public schools in Hawai‘i in 2007–2008 and represents approximately 38% of the total Hawai‘i population for those aged 4 to 5 years, since kindergarten is not a requirement. A limited data set with data on age, sex, height, and weight was used to calculate BMI (body mass index) percentiles. We compare this data with age and sex-specific BMI obtained from Student Health Records from 10,199 children aged 4 to 5 years entering public schools during 2002–2003. The results illustrate that like the 2002–2003 data (28.5%), over one in four (28.6%) of the children aged 4 to 5 years entering Hawai‘i public schools in 2007–2008 were either overweight or obese. Total proportions overweight and obese were persistently higher (32.5% or more in both 2002–2003 and 2007–2008) in some specific school complexes on O‘ahu as well as in some rural and Neighbor Island school complexes. Physicians, public health and school health professionals, advocates, schools, and communities should be vigilant about this persistent problem and seek to implement practices to combat overweight and obesity. In addition, the use of Student Health Records for on-going pediatric obesity surveillance should be explored more fully.  相似文献   
3.
BACKGROUND AND AIM OF THE STUDY: A significant proportion of patients with severe valvular aortic stenosis (AS) and preserved left ventricular (LV) systolic function have low transvalvular gradients. The study aim was to determine the mechanisms and outcome of patients with this hemodynamic profile of AS. METHODS: Among 1,679 patients who underwent transthoracic echocardiography for the evaluation of AS at the authors' institution, 215 (105 females, 110 males; mean age: 77 +/- 10 years) had isolated AS (mean aortic valve area index 0.39 +/- 0.1 cm2/m2), normal sinus rhythm and normal LV ejection fraction. The mean follow up was 23 +/- 12 months, and the end-points were mortality, aortic valve replacement (AVR), or mortality or AVR. RESULTS: Forty-seven patients had a transvalvular mean gradient (MG) <30 mmHg (MG(low)) and 168 had MG > or = 30 mmHg (MG(high)). Compared to MG(high), the MG(low) group had a higher prevalence of hypertension, lower LV end-diastolic volume index (47 +/- 9 versus 56 +/- 12 ml/m2, p <0.0001), lower LV stroke vol-ume index (37 +/- 12 versus 41 +/- 11 ml/beat, p <0.0002), a lesser severity of stenosis (aortic valve area index 0.37 +/- 0.09 versus 0.46 +/- 0.09 cm2/m2, p <0.0001) and a higher systemic vascular resistance (2163 +/- 754 versus 1879 +/- 528 dyne cm s(-5). The LV end-diastolic volume index, systemic vascular resistance and energy loss index were predictors of MG <30 mmHg (OR = 0.30, 95% CI, 0.12, 0.62; OR = 3.05, 95% CI, 1.71, 6.26; and OR = 6.76, 95% CI, 3.44,15.38, respectively). MG <30 mmHg (MGhigh) was associated with almost 50% lower referral to surgery and a two-fold increase in preoperative mortality. CONCLUSION: In severe AS with a normal LV ejection fraction, MG <30 mmHg is related to a lesser severity of stenosis, a smaller LV volume, a lower flow rate and a higher systemic vascular resistance. Compared to the MG(high) group, these patients were less frequently referred to surgery and had a higher mortality.  相似文献   
4.

Objective:

to analyze the possibilities of help/support through the mapping and acknowledgement of the social network of women who denounce experiences of violence at a Police Precinct for Women.

Method:

qualitative study based on the theoretical-methodological framework of Lia Sanicola''s Social Network, through interviews with 19 women.

Results:

the analysis of the network maps evidenced that the primary social network was more present than the secondary on and, despite consisting of significant relations, it demonstrates limitations. The women access the secondary network occasionally in the violence problem and/or its repercussions in their life and health. The discrete presence of the health network in the composition of the social network was revealed and, when mentioned, the relation between the health professional and the woman was characterized as fragile.

Conclusion:

the importance of the social network relates to the creation of spaces of help/support for the women beyond the moment of the aggression, which accompany them throughout their process of emancipation from an experience annulled by violence, considering that each woman acts and makes decisions in the relational context when she is ready for it.  相似文献   
5.
6.

Aim

To establish allele frequencies and genetic parameters for 5 new European Standard Set short tandem repeat (STR) loci in the population of Romania and to compare them with those in other populations.

Methods

DNA was isolated using QIAamp 96 DNA Swab BioRobot Kit and Chelex 100 methods. Polymerase chain reaction amplification was done using Investigator ESSplexPlus Kit (D1S1656, D2S441, D2S1338, D3S1358, D8S1179, D10S1248, D12S391, D16S539, D18S51, D19S433, D21S11, D22S1045, FGA, TH01, and vWA). For DNA typing, Applied Biosystems 3500/3500xL Genetic Analyzer was used. Statistical analysis was done using Powerstats, GDA, and Arlequin software.

Results

Power of discrimination and polymorphism information content was highest for two new ESS loci, D1S1656 and D12S391. Comparison of allele frequencies for 5 new ESS loci in Romanian population with previously published population data showed significant differences for all compared populations, with the exception of Hungary. Geographically more distant populations, such as Spain, Sweden, United Kingdom, Germany, and Portugal differed more than closer populations.

Conclusion

New ESS STR loci are very useful for the analysis of forensic samples (persons or traces) due to their characteristics (shortness and high polymorphism). In comparisons with other common STR markers, they have a higher power of discrimination and also higher polymorphism information content, and could be used in any national DNA database.The establishment of standard sets (or common sets) of short tandem repeat (STR) markers which had first been a necessity for the forensic scientific community, as a result of globalization became a necessity for the worldwide law enforcement agencies. STR markers standard sets facilitate communication and judicial transmission of the forensic DNA typing results between different forensic groups or countries (1).Although several STR sets have been proposed (2), three of them are most frequently used: Interpol Standard Set of Loci – ISS (FGA, TH01, VWA, D3S1358, D8S1179, D18S51, D21S11), US Core Loci – CODIS (CSF1PO, FGA, TH01, TPOX, VWA, D3S1358, D5S818, D7S820, D8S1179, D13S317, D16S539, D18S51, D21S11), and European Standard Set of Loci – ESS (D3S1358, VWA, D8S1179, D21S11, D18S51, TH01, FGA, D1S1656, D2S441, D10S1248, D12S391, D22S1045).The five new European Standard Set STR loci studied in Romanian population are an upgrade of an earlier version of ESS consisiting of 7 STRs (3), adopted by the European Council in 2001. The DNA Working Group of the European Network of Forensic Science Institutes (ENFSI) reviewed the usefulness of the ESS in light of the increased exchange of DNA analysis results in 2009 and recommended the expansion with 5 new ones (4).Romania adopted the new 5 ESS loci and started to use them at the national level at the beginning of 2012 as part of the Investigator ESSplex Plus Kit, which replaced the AmpFlSTR Identifiler PCR Amplification Kit used before for Romanian National DNA Database supplying. As a consequence, and due to the lack of any study involving D10S1248, D22S1045, D2S441, D1S1656, and D12S391 loci in the Romanian population, allele distribution and genetic parameters of these loci have to be determined. The aim of this study was to establish allele frequencies and genetic parameters for 5 new ESS loci in population of Romania and to compare them with those in other populations .  相似文献   
7.
8.
In this research work, silica nanoparticles and silica-gentamicin nanostructured solution were synthesized by using the microwave-assisted synthesis, in basic medium, using two silane precursors (tetraethylorthosilicate and octyltriethoxysilane) and the antibiotic (gentamicin sulfate). The prepared materials were characterized through Fourier transform infrared (FTIR) spectroscopy, TGA analysis, transmission electron microscopy (TEM), and atomic force microscopy (AFM) to investigate the morphology and structure. Antimicrobial studies of the silica-gentamicin nanostructured solution versus silica nanoparticles were performed against Pseudomonas aeruginosa, Staphylococcus aureus, and Escherichia coli. FTIR spectra showed that the gentamicin has been loaded to the silica nanoparticles. AFM analysis showed that the morphology of the silica-gentamicin nanostructured solution has changed, and agglomerations of particles are present at the surface. Antimicrobial testing, performed using the diffusion method through spot inoculation, indicates that the silica-gentamicin nanostructured solution exhibited activity against the resistant strain. The obtained silica-gentamicin solution can be used as biochemical agent for the prevention and treatment of microorganisms which are deposited on different surfaces (e.g., glass, plastic, ceramic).  相似文献   
9.
10.
The esophageal scintigraphy is a technique used to evaluate the motility and the clearance of the esophagus. The patients with achalasia of the cardia were evaluated, before treating them with pneumatic dilatation and after. The reason is to evaluate the efficiency of the pneumatic dilatation technique in the treatment of esophageal achalasia. The pneumatic dilatation with an instrument type Rigiflex is a well/handled and used technique in our clinic. In the study 22 patients were included and we had in view the esophageal transit time and the residuary radioactivity before and after the pneumatic dilatation. We established an important statistical improvement of the data obtained after the dilatation comparative with the data before the treatment (p < 0.01).  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