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   144篇
  免费   8篇
  国内免费   1篇
耳鼻咽喉   3篇
儿科学   4篇
妇产科学   9篇
基础医学   13篇
口腔科学   6篇
临床医学   9篇
内科学   24篇
皮肤病学   2篇
神经病学   2篇
特种医学   3篇
外科学   42篇
综合类   2篇
预防医学   3篇
眼科学   15篇
药学   9篇
肿瘤学   7篇
  2023年   1篇
  2021年   1篇
  2018年   2篇
  2017年   7篇
  2016年   10篇
  2015年   6篇
  2014年   7篇
  2013年   6篇
  2012年   16篇
  2011年   18篇
  2010年   8篇
  2009年   11篇
  2008年   15篇
  2007年   9篇
  2006年   8篇
  2005年   10篇
  2004年   7篇
  2003年   3篇
  2002年   2篇
  2001年   1篇
  1999年   3篇
  1992年   2篇
排序方式: 共有153条查询结果,搜索用时 15 毫秒
1.
BACKGROUND: The purpose of this study was to examine the diagnostic efficiency of prostate-specific antigen (PSA) and digital rectal examination (DRE) testing when using either 4.0 ng/ml or an age-specific reference range (ASRR) as an abnormal cutoff PSA value. METHODS: Between 1992-1995, 116,073 men, aged 40-79 years, were screened during Prostate Cancer Awareness Week. When using a 4.0-ng/ml cutoff PSA value, 22,014 had either an abnormal PSA, an abnormal DRE, or both. When using an ASRR cutoff PSA value, 17,561 had either an abnormal PSA, an abnormal DRE, or both. The positive predictive value (PPV), sensitivity, and specificity of PSA, DRE, and combined PSA and DRE tests were evaluated. RESULTS: When using a 4.0-ng/ml cutoff PSA value, the PPVs of abnormal PSA alone, abnormal DRE alone, and combined abnormal PSA and DRE tests were 27.7%, 17.7%, and 56.0%, respectively. Sensitivities were 34.9%, 27.1%, and 38.0%, respectively. Specificities were 63.1%, 49.0%, and 87.9%, respectively. When using an ASRR cutoff PSA value, the PPVs of each category were 31.8%, 20.8%, and 63.7%, respectively. Sensitivities were 27.1%, 41.0%, and 31.8%, respectively. Specificities were 75.0%, 32.8%, and 92.2%, respectively. The PPVs of the PSA test were higher than those of the DRE. The PPVs of combined tests were highest when using either a 4.0-ng/ml cutoff PSA value or an ASRR cutoff PSA value (all P < 0.001). When using an ASRR, the PPVs of PSA, DRE, and combined tests were higher than those when using a 4.0-ng/ml without statistical significance (all P > 0.05). Sensitivity of PSA when using an ASRR was lower than when using 4.0 ng/ml. CONCLUSIONS: Significantly higher PPVs indicated that utilizing both a PSA test and a DRE is most effective in screening for the early detection of prostate cancer. Although higher PPVs when using an ASRR cutoff PSA value suggested fewer unnecessary biopsies, lower sensitivities resulted in fewer cancers detected. Thus, we recommend that the combination of a PSA test with a cutoff value of 4.0 ng/ml and a DRE should continue to be utilized in the screening programs.  相似文献   
2.
3.
Objective: The purpose of this study was to examine the vasoreactivity in retina and choroid of the healthy eyes in response to experimentally altered partial arterial pressure of carbon dioxide (PaCO2) using a non-invasive technique, spectral domain optical coherence tomography (SD-OCT).

Materials and methods: The study included non-smoking participants between 18 and 35 years of age, having visual acuity of 20/20 and with no systemic and ocular diseases. At baseline, the participants breathed room air (normocapnia). Hypocapnia was created with the help of hyperventilation; for this, the participants were instructed to draw deep and quick breaths, resulting one breathing cycle per 2?s. To create hypercapnia subjects rebreathed from a 5?l bag at least 3?min. Choroidal thickness and retinal artery diameter were measured at baseline, and hyperventilation and rebreathing conditions by SD-OCT.

Results: Twenty eyes of 20 healthy subjects were included in this study. Their mean age was 24.90?±?5.32 years. Hyperventilation caused a significant reduction in choroidal thickness, compared with baseline, at all points; whereas rebreathing caused no significant change at all points. The mean diameters of the arteries were 151.80?±?7.88?μm, with a significant decline to 148.90?±?7.25?μm at hyperventilation condition and a significant increase to 153.50?±?7.88?μm at rebreathing condition (p?=?0.018, p?=?0.043, respectively).

Conclusion: This study demonstrated that, SD-OCT was a useful tool in measuring the ocular vascular response under hypercapnia and hypocapnia conditions. These findings may be helpful for further understanding the physiological nature of ocular blood flow and this preliminary study provides a basis for future studies.  相似文献   
4.
Behçet's disease (BD) is a systemic autoimmune disorder. Cytochrome P450 enzymes (CYPs) are responsible for various drug metabolism reactions as well as those of endogenous substances which may be associated with autoimmune disease susceptibility. Recently, we reported that in patients with BD, CYP2C9 seems to be down‐regulated due to inflammation. In the same Turkish patients with BD, we investigated whether also CYP2C19 activity is decreased. Lansoprazole (30 mg) was given as a probe drug to evaluate CYP2C19 activity in 59 patients with BD and 27 healthy control volunteers. An HPLC method was used to determine plasma lansoprazole and its metabolite, 5‐hydroxy lansoprazole, concentrations. The genotyping for CYP2C19 *2, *3 and *17 polymorphisms was made using PCR‐RFLP. The median lansoprazole/5‐hydroxy lansoprazole metabolic ratio (MR) in patients with BD was 2.6‐fold higher as compared to the healthy control group (p = 0.001, 22.6 (1.3–26) and 8.8 (0.5–140) as median and range, respectively). The CYP2C19*17*17 genotype frequency was found to be significantly less in the BD group as compared to the healthy controls (1.7% versus 14.8% in controls, p = 0.01). Additionally, colchicine treatment did not affect the CYP2C19 enzyme activity in six patients (p = 0.43). In conclusion, the patients with BD had lower CYP2C19 enzyme activity and lower frequency of the CYP2C19*17 allele as compared to those of the healthy controls. Further studies are warranted on the mechanisms underlying this relation. This study should also be applied to other autoimmune diseases similarly characterized by local or systemic inflammation.  相似文献   
5.
6.
7.
This study evaluated the in vitro effects of the combination of a carbapenem (imipenem or meropenem) with a quinolone (ciprofloxacin or levofloxacin) using a microbroth dilution chequerboard technique and multidrug-resistant Pseudomonas aeruginosa strains. The ciprofloxacin and meropenem combination was only synergistic against 2 strains (6.2%) and ciprofloxacin and imipenem against 1 strain (3.1%). Levofloxacin and imipenem or meropenem were not synergistic for against any strain. None of the combinations showed an antagonistic effect.  相似文献   
8.
9.
10.
PURPOSE: To report the results of transscleral implantation of foldable intraocular lenses (IOLs). SETTING: Department of Ophthalmology Dokuz Eylül University School of Medicine, Izmir, Turkey. METHODS: Twenty eyes of 20 patients had transscleral fixation of a foldable IOL combined with conventional 3-port pars plana vitrectomy or anterior vitrectomy. Twelve eyes had lens luxation, 8 traumatic and 4 idiopathic. Six eyes were aphakic, 3 after extracapsular cataract extraction and 3 as a result of complicated phacoemulsification. One patient with a mature cataract and pseudoexfoliation had a wide zonular dialysis during phacoemulsification. One patient had an opacified hydrophilic acrylic IOL. RESULTS: The mean age of the patients was 52.9 years (range 17 to 80 years). The mean preoperative best corrected visual acuity (BCVA) was 20/63 (range counting fingers to 20/25). The mean preoperative refraction was +10.8 diopters (D) (range +10 to +13 D) and the mean preoperative astigmatism, 1.8 D (range 1.0 to 5.5 D). Sixteen IOLs were hydrophobic acrylic, 14 of which were 3-piece AcrySof MA60BM (Alcon) and 2 of which were Sensar AR40 (Allergan). Four IOLs, all VisaAcryl(Staar), were hydrophilic acrylic. The mean power of the IOLs was +22.0 D (range 19.0 to 26.0 D). The mean follow-up was 12 months (range 1 to 18 months). The postoperative BCVA ranged between 20/100 and 20/20, and the mean postoperative astigmatism was 1.1 D (range 0.5 to 4.0 D) at the last follow-up visit. The difference was statistically significant (P<.05). Suture exposure and cystoid macular edema were the only complications, each occurring in 2 eyes. CONCLUSION: Transscleral fixation of foldable IOLs takes less time and results in fewer complications and better visual outcomes.  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