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61.
Bilal Gokce Eric J. Adles David E. Aspnes Kenan Gundogdu 《Proceedings of the National Academy of Sciences of the United States of America》2010,107(41):17503-17508
In-plane directional control of surface chemistry during interface formation can lead to new opportunities regarding device structures and applications. Control of this type requires techniques that can probe and hence provide feedback on the chemical reactivity of bonds not only in specific directions but also in real time. Here, we demonstrate both control and measurement of the oxidation of H-terminated (111) Si. Control is achieved by externally applying uniaxial strain, and measurement by second-harmonic generation (SHG) together with the anisotropic-bond model of nonlinear optics. In this system anisotropy results because bonds in the strain direction oxidize faster than those perpendicular to it, leading in addition to transient structural changes that can also be detected at the bond level by SHG. 相似文献
62.
Balci A Karazincir S Gorur S Sumbas H Egilmez E Inandi T 《Journal of clinical ultrasound : JCU》2008,36(3):148-152
PURPOSE: To investigate the long-term effect of varicocele repair on ipsilateral intratesticular arterial resistance index (RI) using color Doppler sonography (CDS). METHODS: A total of 26 infertile patients with left varicocele who underwent a testicular artery and lymphatic-sparing subinguinal varicocelectomy were examined with CDS for intratesticular flow parameters before and at least 6 months after surgery. We also evaluated preoperative and postoperative semen parameters. RESULTS: The mean values of RI, end-diastolic velocity and pulsatility index decreased significantly after surgery, whereas no significant change was observed in peak systolic velocity. Repair of the varicocele resulted in a statistically significant increase in the total sperm count, motility, morphology, and total motile sperm count. However, no significant correlation was found between sperm parameters and RI values (p > 0.05). CONCLUSIONS: Our data show that a significant improvement occurs in testicular blood supply and sperm parameters after surgical varicocele repair, without significant correlation between these 2 changes. 相似文献
63.
Balci A Karazincir S Sumbas H Oter Y Egilmez E Inandi T 《Journal of clinical ultrasound : JCU》2008,36(3):134-140
PURPOSE: To investigate the effects of various degrees of diffuse fatty infiltration of the liver on portal vein blood flow with Doppler sonography. METHODS: One hundred forty subjects were examined with color and spectral Doppler sonography. The subjects were divided into 4 groups of 35 subjects each according to the degree (normal, grade 1, grade 2 and grade 3) of hepatic fatty infiltration assessed on gray-scale images. The portal vein pulsatility index (VPI) and time-averaged mean flow velocity (MFV) were calculated for each subject. VPI was calculated as (peak maximum velocity - peak minimum velocity) / peak maximum velocity. RESULTS: VPI and MFV values were, respectively, 0.32 +/- 0.06 and 16.8 +/- 2.6 cm/second in the normal group, 0.27 +/- 0.07 and 14.2 +/- 2.2 cm/second in the group with grade 1 fatty infiltration, 0.22 +/- 0.06 and 12.2 +/- 1.8 cm/second in the group with grade 2 fatty infiltration, and 0.18 +/- 0.04 and 10.8 +/- 1.5 cm/second in the group with grade 3 fatty infiltration. There was a negative inverse correlation between the grade of fatty infiltration and both VPI (f = 55.3, p < 0.001) and MFV (f = 43.9, p < 0.001). CONCLUSION: The pulsatility index and mean velocity of the portal vein blood flow decrease as the severity of fatty infiltration increases. 相似文献
64.
Pirat B Atar I Ertan C Bozbas H Gulmez O Müderrisoglu H Ozin B 《The American journal of cardiology》2007,100(10):1552-1555
C-reactive protein (CRP) was increased in patients with atrial fibrillation (AF). The aim of this study was to evaluate CRP after inducing AF in 39 patients undergoing electrophysiologic study (EPS). After a diagnostic EPS, programmed atrial stimulation with 3 extra stimuli from the right atrium was performed in all patients. CRP was measured before and 6 and 24 hours after the procedure. Patients in whom AF was induced were monitored for 24 hours. AF was induced in 18 of 39 patients. Twenty-one patients without a tachyarrhythmia constituted the control group. Groups were similar with regard to age, gender, incidences of hypertension and diabetes, and history of coronary artery disease. On average, AF lasted 4.8 hours, and spontaneous conversion to sinus rhythm was observed in all patients. There were no statistically significant differences with respect to baseline and 6-hour CRP values between groups. However, mean CRP at 24 hours was significantly higher in patients with AF compared with controls (10 +/- 11 and 3.9 +/- 4.2 mg/L; p = 0.04). In conclusion, induction of AF during EPS led to increased CRP. This finding suggested that increased CRP may be the consequence of AF. 相似文献
65.
Colkesen Y Acil T Demircan S Sezgin AT Ozin B Muderrisoglu H 《The international journal of cardiovascular imaging》2008,24(2):159-163
Background. There are several risk factors for the initiation of paroxysmal atrial fibrillation (PAF) and the underlying mechanisms
are multifactorial. Our study aims to explore the echocardiographic parameters that can identify in patients with PAF compared
to normal subjects. Methods. Eighty consecutive patients who were with PAF detected by 24-h Holter monitoring (HM) were assigned in our study. The control
group (n = 80) consisted individuals with no PAF on HM. Indication for HM was palpitations at rest. All patients underwent routine
echocardiographic evaluation. Patients with aortic and mitral stenosis, hyperthyroidism, and hypothyroidism were excluded
from the study. Comprehensive clinical data were collected. Results. Mean age of the patients with PAF was 63 ± 11 years and of those 42% were male subjects. There was no difference in the
prevalence of hypertension in both groups. Mean left ventricular ejection fraction (LVEF) was 57 ± 15% in PAF group and 64
± 2% in control subjects (p < 0.001). Mean values of left atrial (LA) diameter for PAF and control groups were 3.7 ± 0.6 cm vs. 3.1 ± 0.4 cm (p < 0.001), respectively. Patients with PAF had more severe valve insufficiency, higher values of mean pulmonary artery systolic
pressures (PAP) (29 ± 10 mmHg vs. 25 ± 2 mmHg, respectively; p = 0.001) and deteriorated MV inflow velocities (E:A ratio 0.9 ± 0.4 vs. 1.1 ± 0.3, respectively; p = 0.008) when compared to control group. In multivariate logistic regression analysis, LA diameter predicted the development
of PAF after adjusted for age and gender. Conclusion. Our results indicate that LA diameter predicts the development of PAF. 相似文献
66.
Guven A Gundogdu G Sadir S Topal T Erdogan E Korkmaz A Surer I Ozturk H 《Journal of pediatric surgery》2008,43(9):1679-1684
Introduction
Ozone has been proposed as an antioxidant enzyme activator, immunomodulator and cellular metabolic activator. This study was designed to investigate the efficacy of ozone therapy in the prevention of esophageal damage and stricture formation developed after esophageal caustic injuries in the rat.Materials and Methods
Forty-five rats were allocated into three groups; sham-operated, un-treatment and treatment groups. Caustic esophageal burn was created by instilling 15% NaOH in the distal esophagus. The rats were left untreated or treated with 1 mg/kg/day ozone intraperitoneally. All rats were sacrificed at 28 days. Efficacy of the treatment was assessed by measuring the stenosis index (SI) and histopathologic damage score, and biochemically by determining tissue hydroxyproline content (HP), superoxide dismutase (SOD), glutathione peroxidase (GPx), malondialdehyde (MDA) and protein carbonyl content (PCC) in esophageal homogenates.Results
Whereas seven (47%) rats died in the un-treatment group, all rats in the sham-operated and the treatment group survived during the study. SI, the histopathologic damage score, was significantly lower in the ozone-therapy group than the un-treatment group. HP levels were significantly higher in the un-treatment group than the group treated with ozone. Caustic esophageal burn increased MDA and PCC levels and also decreased SOD and GPx enzyme activities. In contrast, ozone therapy decreased the elevated MDA and PCC levels and also increased the reduced SOD and GPx enzyme activities.Conclusion
Ozone has a preventive effect in the development of fibrosis by decreasing tissue damage and increasing the antioxidant enzyme activity in an experimental model of corrosive esophageal injury. 相似文献67.
68.
69.
Secondary amyloidosis (SA) affects cardiac texture and function by interstitial fibrosis. Doppler tissue imaging (DTI) may
quantify heart function through the assessment of myocardial velocities. Echocardiographic findings of early cardiac amyloidosis
(CA) without heart failure (HF) caused by SA were determined both by standard methods and DTI. It was then determined whether
DTI is superior to conventional echocardiography in documenting early CA due to SA. Twenty-five patients with SA who had CA
without HF (group 1) were compared with 25 healthy control subjects (group 2). After standard echocardiography, systolic (s),
early (e) and late diastolic (a) velocities of interventricular septum, anterolateral, and anterior and inferior walls were
measured from mitral annulus by DTI. The averages were called (smean), (emean), and (amean), respectively. Fractional shortening (FS) and ejection fraction (EF) values of groups 1 and 2 were similar. Standard Doppler
echocardiographic values were not typical for a specific diastolic abnormality. The (smean) and (emean) for group 1 were lower but (amean) was higher compared with group 2 (all P < .05). The group 1 (emean/amean) was lower (P < .0001) and (E/emean) was higher (P=.003) than in group 2 (both P < .05). (E/emean) and (E/elateral wall) ratios were positively correlated (r=0.74, P < .05). In patients with early CA due to SA without HF, by DTI, (smean) and (emean) velocities decrease and (amean) velocity increases. These may be markers of subclinical CA of SA when standard echocardiography is not informative. (E/emean) ratio may be an alternative index to (E/elateral wall). 相似文献
70.
Ilyas Atar Mehmet Emin Korkmaz Inci Asli Atar Oyku Gulmez Bulent Ozin Huseyin Bozbas Tansel Erol Alp Aydinalp Aylin Yildirir Muammer Yucel Haldun Muderrisoglu 《European heart journal》2006,27(5):547-552
AIMS: Beta-blockers (BBs) have been shown to improve survival and reduce the risk of re-infarction in patients following myocardial infarction. There are conflicting data about the effects of BB therapy on cardiac biomarkers after percutaneous coronary interventions (PCIs). The aim of the study was to investigate the effects of BB use on cardiac troponin-I (cTnI) levels in patients who had undergone elective PCI. METHODS AND RESULTS: In this prospective study, 287 patients with coronary artery disease were included. Patients were randomized either to BB or control groups prior to the intervention. Blood samples for cTnI were obtained before and at 6, 24, and 36 h after the procedure. Of the 287 patients included, 143 received metoprolol succinate 100 mg/day, and 144 received no BB and served as the control group. Baseline clinical characteristics of both groups, except for history of coronary artery bypass graft surgery, were similar. We observed no significant difference in the elevation of cTnI levels between the two groups after PCI (BB group, 17 patients, 11.9%; control group, 10 patients, 6.9%; P=0.2). CONCLUSION: Metoprolol succinate therapy seems to have no cardioprotective effect in limiting troponin-I rise after PCI. 相似文献