首页 | 官方网站   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   90篇
  免费   0篇
医药卫生   90篇
  2021年   6篇
  2019年   1篇
  2018年   3篇
  2017年   1篇
  2016年   1篇
  2015年   4篇
  2014年   6篇
  2013年   6篇
  2012年   8篇
  2011年   13篇
  2010年   5篇
  2008年   2篇
  2007年   7篇
  2006年   2篇
  2005年   4篇
  2004年   3篇
  2003年   1篇
  2002年   2篇
  2001年   5篇
  2000年   1篇
  1999年   5篇
  1998年   1篇
  1994年   1篇
  1991年   1篇
  1987年   1篇
排序方式: 共有90条查询结果,搜索用时 93 毫秒
41.
A comparison between phospholipid-coated microbubbles with and without liposomes attached to the microbubble surface was performed using the ultra-high-speed imaging camera (Brandaris 128). We investigated 73 liposome-loaded microbubbles (loaded microbubbles) and 41 microbubbles without liposome loading (unloaded microbubbles) with a diameter ranging from 3–10 μm at frequencies ranging from 0.6–3.8 MHz and acoustic pressures ranging from 5–100 kPa. The experimental data showed nearly the same shell elasticity for the loaded and unloaded bubbles, but the shell viscosity was higher for loaded bubbles compared with unloaded bubbles. For loaded bubbles, a higher pressure threshold for the bubble vibrations was noticed. In addition, an “expansion-only” behavior was observed for up to 69% of the investigated loaded bubbles, which mostly occurred at low acoustic pressures (≤30 kPa). Finally, fluorescence imaging showed heterogeneity of liposome distributions of the loaded bubbles.  相似文献   
42.
The dynamics of coated microbubbles was studied in an in vivo model. Biotinylated lipid-coated microbubbles were prepared in-house and were injected into a chick embryo chorioallantoic membrane (CAM) model on the fifth day of incubation. The microbubbles, ranging between 1.0 and 3.5 μm in diameter, were insonified in the frequency range of 4–7 MHz. Two amplitudes of acoustic pressure were applied: 300 kPa and 400 kPa. The fundamental and subharmonic responses were recorded optically with an ultra-fast camera (Brandaris 128) at 20 million frames per second. A subharmonic response was observed for 44% of the studied bubbles. From the data the frequency of the maximum fundamental and subharmonic response was derived for each individual bubble and resulted in the resonance curves of the microbubbles. All the bubbles showed shell (strain) hardening behavior for a higher acoustic pressure. We conclude that the subharmonic oscillations observed in this study belonged to the transmit at resonance (TR) regime.  相似文献   
43.
BACKGROUND AND AIM OF THE STUDY: The study aim was to examine comparatively the effects of prosthetic and homograft valves in the aortic position on ventricular hemodynamics and structure. METHODS: Hemodynamic evaluations were performed at rest and during exercise in 38 patients who had undergone aortic valve replacement (AVR) with either a homograft (n = 19) or prosthetic valve (19-23 mm; n = 19). Using echocardiographic, electrocardiographic and hematologic methods, the pressure gradient (PG); aortic valve area; diameters of left anterior wall, posterior wall (PW) and interventricular septum (IVS); ejection fraction (EF); left ventricular mass (LVM) and mass index (LVMI); electrocardiographic data of LV hypertrophy; hemoglobin; hematocrit and lactate dehydrogenase (LDH) levels were measured. RESULTS: LVM and LVMI decreased significantly after surgery in both groups (p<0.001), but the decrease was significantly greater in the homograft group (p<0.05). The IVS and PW diameters in the homograft group decreased significantly postoperatively (p<0.05); the inter-group difference was also significant (p<0.01). In the homograft group there was a significant improvement in EF (p<0.05), and the exercise PG was significantly less. Both groups showed improved LV hypertrophy and correlation between V1S >24 mm criteria and LVMI measurements. Postoperative LDH levels in the homograft group were significantly lower than preoperative levels (p<0.05); the intergroup difference was also significant (p<0.001). CONCLUSIONS: Our data suggest that homografts, as compared to mechanical prostheses, provide significantly better hemodynamics in the aortic position.  相似文献   
44.
45.
Coronary artery bypass grafting (CABG) in patients with poor left ventricular function remains a surgical challenge and is still controversial. The purposes of this study were to evaluate the effectiveness of CABG in such patients when performed without case selection on the basis of preoperative viability tests and to determine the predictors of postperative outcome. The preoperative, perioperative, and postoperative early and mid-term follow-up data of 273 patients with < or = 30% left ventricular ejection fraction (LVEF) who underwent isolated CABG between January 1995 and November 2000 were evaluated. Preoperative echocardiography and cardiac catheterization, and postoperative control echocardiography were performed in all patients. Follow-up was achieved via monthly periodical examinations in the first 6 months, and thereafter by either regular visits or phone contact. Preoperatively, 242 (88.65%) patients were in NYHA class III or IV, and the mean LVEF was 26.51 +/- 3.64%. The overall hospital mortality total was 14 (5.13%) patients. There were 44 (16.12%) late mortalities. Postoperative morbidities were observed in 74 (27.1%) patients. Two-hundred and two (93.95%) of the surviving 215 (78.75%) patients were in NYHA class I or II at 49.55 +/- 14.84 months of follow-up. Postoperative follow-up echocardiographic examinations revealed a mean LVEF of 39.66% +/- 5.43%. The improvements in functional capacity and LVEF were significant. Advanced age, diabetes, hypertension, cross-clamp time >60 min, bypass time>120 min, and severity of functional class (class III-IV of NYHA) were found to be the determinants of mortality. However, multivariate analyses revealed only older age and class III-IV of NYHA and CCS were predictors of mortality. The low mortality and morbidity rates as well as satisfactory postoperative improvements in functional capacity and LVEF measurements support the use of CABG without the need for any viability assessment in patients with left ventricular dysfunction.  相似文献   
46.
[Purpose] Breast cancer-related upper extremity lymph edema is known to cause physical, functional and psychological impairments in women after modified radical mastectomy. The aim of this study was to investigate the effects of phase I Complex Decongestive Physiotherapy (CDP) on physical functions and depression levels in women with breast cancer-related upper extremity lymph edema. [Subjects and Methods] Fifty-eight subjects with breast cancer-related upper extremity lymph edema were the subjects of this study. The arm circumference, shoulder range of motion (ROM), muscle strength and depression levels of the subjects were assessed before and after phase I CDP treatment. [Results] After phase I CDP, there was a statistically significant reduction in circumference measurements at all levels of the affected arm. There was not any statistically significant difference in muscle strength after CDP. The shoulder ROM improved after treatment. There was a significant reduction in the Beck Depression Inventory score. A significant positive correlation was found between depression levels and circumference measurement. [Conclusion] Based on the results we suggest that by reducing limb volume, beside improving physical functions, phase I CDP can affect psychological status, especially depression which is very common in women with breast cancer-related upper extremity lymph edema.Key words: Lymph edema, Complex decongestive physiotherapy, Depression  相似文献   
47.
IntroductionThe cultural adaptation of a self-report measurement in different languages is important for developing common strategies for evaluation and treatment. The Neck Bournemouth Questionnaire (NBQ), which was developed to evaluate patients with neck pain, was adapted from the Bournemouth Questionnaire in accordance with the International Classification of Functioning, Disability and Health (ICF) categories. The aim of this study was to conduct the Turkish cultural adaptation, validity and reliability study of the NBQ.Material and methodsThe study included 119 patients (93 females, 26 males; mean age: 37.2 ±11.8 years) with chronic nonspecific neck pain. The NBQ, Neck Disability Index (NDI) and Nottingham Health Profile (NHP) questionnaires were administered to all the subjects. Test-retest reliability (intraclass correlation coefficient) and the internal consistency (Cronbach’s α) were the methods used for the reliability study. The relationship between NBQ, NDI and NHP was investigated for concurrent validity. Exploratory and confirmatory factor analysis was used for construct validity.ResultsThe Neck Bournemouth Questionnaire showed good internal consistency (α = 0.87). The test-retest reliability coefficient was 0.913 (95% CI: 0.875–0.940). The correlations between NBQ and NDI and NHP were significant (p < 0.05). The questionnaire was found to have one factor and the explained variance was 59.084% as a result of factor analysis.ConclusionsThe Neck Bournemouth Questionnaire is a valid and reliable scale for patients with chronic neck pain in the Turkish population.  相似文献   
48.
We report a convenient method for the synthesis of 3,5-anhydrofuranose derivatives. Formation of the 3,5-anhydro (oxetane) rings was achieved by the Wittig-cyclization procedure under acid promoted conditions starting from 5(E)-eno-1,4-furano-7-ulose derivatives (1, 4, and 7). Unprotected hydroxyl groups on C-3 of the furanose rings added intramolecularly to the acyclic double bond under very mild acidic conditions in methanol to form the stereoisomeric 3,5-anhydro derivatives in good yields. The products (2, 3, 5, 6, and 8) were found to exhibit antibacterial properties. The reaction was found to be strongly solvent dependent as use of methanol instead of chloroform afforded 5-acetylmethyl-furfural 9 as a major product instead of the expected oxetane. All of the synthesized compounds were tested for antimicrobial activity against Staphylococcus aureus ATCC6538-P, Bacillus subtilis ATCC 6633, Salmonella typhimurium CCM 5445, Enterococcus faecalis ATCC 29212, Escherichia coli ATCC 12228, Pseudomonas aeruginosa ATCC 27853, Klebsiella pneumoniae CCM 2318, and Candida albicans ATCC 10239 and exhibited a range of activities against selected microorganisms.  相似文献   
49.
International Urology and Nephrology - There are scanty data on the rate of abnormal Tc-99&nbsp;m dimercaptosuccinic acid (DMSA) renal scintigraphy and associated factors in children older than...  相似文献   
50.
The present study examined the use of antibiotics with respect to the rate of Chlamydia trachomatis positivity. Our subjects were 282 sexually active Turkish females between the ages of 15 and 42. Endocervical samples were investigated in 60 women with pelvic inflammatory diseases (PIDs), 90 infertile patients (IPs), 92 registered commercial sex workers (CSWs), and 40 intrauterine device (IUD) users. All samples were analyzed using direct immunofluorescence test techniques for the presence of C. trachomatis antigen, which was found in 12.7% of our subjects, with positive results as high as 26% in patients between 21 and 30 years of age. C. trachomatis positivity was found to be 16.6% in PID patients, and 23.3% in IPs, and 5.4% in CSWs; however, it was not found among IUD users. The rate of positivity was highest in IPs; and lowest in registered CSWs (P < 0.05), who are periodically examined for the presence of sexually transmitted diseases, as required by Turkish authorities. Interestingly, the usage of therapeutic or prophylactic antibiotics such as tetracycline and ceftriaxon was found to be quite high among IUD users (90% use of tetracycline) and CSWs (100% use of both antibiotcs). Our results show that C. trachomatis positivity in the southeast region of Turkey is not significantly higher than that found in previous studies on sex workers of other countries. Additionally, our results indicate the use of prophylactic antibiotics decreases the rate of chlamydial infections.  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-23

京公网安备 11010802026262号