87 research outputs found
Effect of Mitomycin - C and Triamcinolone on Preventing Urethral Strictures
Urethral stricture is a common disease with high recurrence rate. Several manipulations were defined to prevent the recurrence but the results were disappointing. This study aimed to evaluate the efficacy of triamcinolone and mitomycin-C on urethral stricture formation and their effect on inhibition of urethral fibrosis. A total of 24 New Zealand rabbits were divided into 3 groups. Urethras of rabbits were traumatized with pediatric resectoscope. Resection area was irrigated with 10mL saline, swapped with a cotton wool soaked with 0.5mg/mL MMC and injected by 40mg triamcinolone in groups 1, 2 and 3 respectively. Retrograde urethrogram was performed at 28th day of procedure and the urethra was removed for histopathologic evaluation. There were significant differences in urethral diameters and in lumen reduction rate between the control and study groups (p< 0.001). Compared to control group, all treatment groups showed mild fibrosis, less collagen bundle irregularity, and lower numbers of fibroblasts (p= 0.003). The Tunnel assay showed that the number of apoptotic cells in the submucosal connective tissue was quantitatively higher in control groups (p= 0.034). In the view of efficacy and safety, MMC and triamcinolone have the potential to replace the use of stents, clean intermittent catheterization, or long term catheters following internal urethrotomy. There were no statistically significant differences between two agents in terms of preventing urethral stricture formation in the present study. Mitomycin C and triamcinolone decreased the recurrence rates of urethral stricture
Age- and region-specific hepatitis B prevalence in Turkey estimated using generalized linear mixed models: a systematic review
Toy M, Önder FO, Wörmann T, et al. Age- and region-specific hepatitis B prevalence in Turkey estimated using generalized linear mixed models: a systematic review. BMC infectious diseases. 2011;11(1): 337.BACKGROUND: To provide a clear picture of the current hepatitis B situation, the authors performed a systematic review to estimate the age- and region-specific prevalence of chronic hepatitis B (CHB) in Turkey. METHODS: A total of 339 studies with original data on the prevalence of hepatitis B surface antigen (HBsAg) in Turkey and published between 1999 and 2009 were identified through a search of electronic databases, by reviewing citations, and by writing to authors. After a critical assessment, the authors included 129 studies, divided into categories: 'age-specific'; 'region-specific'; and 'specific population group'. To account for the differences among the studies, a generalized linear mixed model was used to estimate the overall prevalence across all age groups and regions. For specific population groups, the authors calculated the weighted mean prevalence. RESULTS: The estimated overall population prevalence was 4.57, 95% confidence interval (CI): 3.58, 5.76, and the estimated total number of CHB cases was about 3.3 million. The outcomes of the age-specific groups varied from 2.84, (95% CI: 2.60, 3.10) for the 0-14-year olds to 6.36 (95% CI: 5.83, 6.90) in the 25-34-year-old group. CONCLUSION: There are large age-group and regional differences in CHB prevalence in Turkey, where CHB remains a serious health problem
The impact of biologics and tofacitinib on cardiovascular risk factors and outcomes in patients with rheumatic disease: a systematic literature review
Introduction Rheumatic diseases are autoimmune, inflammatory diseases often associated with cardiovascular (CV) disease, a major cause of mortality in these patients. In recent years, treatment with biologic and targeted synthetic disease-modifying anti-rheumatic drugs (DMARDs), either as monotherapy or in combination with other drugs, have become the standard of treatment. In this systematic literature review, we evaluated the effect of treatment with biologic or tofacitinib on the CV risk and outcomes in these patients. Methods A systematic search was performed in MEDLINE, Embase, the Cochrane Central Register of Controlled Trials, and Cochrane Database of Systematic Reviews for articles reporting on CV risk and events in patients with rheumatic disease treated with a biologic agent or tofacitinib. Articles identified were subjected to two levels of screening. Articles that passed the first level based on title and abstract were assessed on full-text evaluation. The quality of randomized clinical trials was assessed by Jadad scoring system and the quality of the other studies and abstracts was assessed using the Downs and Black instrument. The data extracted included study design, baseline patient characteristics, and measurements of CV risk and events. Results Of the 5722 articles identified in the initial search, screening yielded 105 unique publications from 90 unique studies (33 clinical trials, 39 prospective cohort studies, and an additional 18 retrospective studies) that reported CV risk outcomes. A risk of bias analysis for each type of report indicated that they were of good or excellent quality. Importantly, despite some limitations in data reported, there were no indications of significant increase in adverse CV events or risk in response to treatment with the agents evaluated. Conclusions Treatment with biologic or tofacitinib appears to be well-tolerated with respect to CV outcomes in these patients
Dysnatremia on intensive care unit admission is a stronger risk factor when associated with organ dysfunction
Aim. Dysnatremia present at the time of intensive care unit (ICU) admission is associated with mortality. In this study, we investigated the epidemiology of dysnatremia present on ICU admission and the impact of organ dysfunction on the association between dysnatremia and mortality. We hypothesized that dysnatremia comorbid with organ dysfunction is associated with higher risk of mortality
The effect of thermal annealing on the series resistance of nearly ideal and ideal Ti/n-GaAs Schottky diodes
The effect of annealing in the temperature range 100-300 degrees C with steps of 100 degrees C for 5 min on characteristic parameters, especially series resistance, of nearly ideal (D1) and ideal (D2) Ti/n-GaAs Schottky barrier diodes (SBDs) has been investigated. Both Ti/n-GaAs SBDs have shown thermal stability up to 300 degrees C annealing. It can be said that the interfacial layer thickness of sample D1 is too thin to hinder thermal stability. The ideality factor and barrier height of samples D1 and D2 have been found to be 1.05 and 0.76 eV and 1.06 and 0.75eV at 300 degrees C respectively, while 1.08 and 0.64eV and 1.01 and 0.67 eV for their as-deposited samples, respectively. The series resistance values have decreased with increasing annealing temperature. This has been attributed to reduction of the native oxide layer by the metal Ti It has been concluded that the annealing to a given temperature has improved the electrical characteristics of both Ti/n-GaAs Schottky contacts due to chemical reactions between substrate and the reactive metals and the native oxide
Thermal treatment of the MIS and intimate Ni/n-LEC GaAs Schottky barrier diodes
The thermal stability of Schottky diode parameters of the fabricated MIS and intimate Ni/n-LEC GaAs Schottky diodes have been investigated using current-voltage (I-V) techniques after being annealed in the range of 100-600 degrees C for 5 min in N-2 atmosphere. It has been seen that the intimate device is thermally mure stable than the MIS device. The I-Ii characteristics of the MIS device were deteriorated after 400 degrees C, while those of the intimate device, after 600 degrees C. This has been attributed to the fact that the MIS Ni/n-LEC GaAs SBDs heated from 100 degrees C to 400 degrees C suffers from problems arising from the native oxide layer formed on the GaAs surface. Thus, it has been concluded that a reacted contact is thermodynamically stable in the absence of the native oxide layer than an unannealed one or than MIS diodes up to a given annealing temperature. Furthermore, we have evaluated the equilibrium interface charge density and the interface state charge density distribution from the forward bias I-V characteristics of the diodes which show MIS diode behavior before and after annealing. The results have supported our interpretations related to the ideality factor and Schottky barrier height. (C) 1998 Elsevier Science B.V. All rights reserved
The effect of series resistance on calculation of the interface state density distribution in Schottky diodes
This work presents an attempt related to the importance of the fact that the series resistance value is considered in calculating the interface state density distribution from the non-ideal forward bias current-voltage (I-V) characteristics of Au/n-Si Schottky barrier diodes (SBDs). To examine the consistency of this approach, Au/n-Si SBDs with Si bulk thicknesses of 200 and 400 mum have been prepared. Both diodes showed non-ideal I-V behaviour with ideality factors of 1.14 and 1.12, respectively, and thus it has been thought that the diodes have a metal-interface layer-semiconductor configuration. At the same energy position near the bottom of the conduction band, the interface state density (N-SS) values, without taking into account the series resistance value of the devices, are almost one order of magnitude larger than the N-SS values obtained taking into account the series resistance value
On the forward bias excess capacitance at intimate and MIS Schottky barrier diodes with perfect or imperfect ohmic back contact
An experimental explanation of the forward bias Capacitance;frequency plots for intimate or MIS SBDs with perfect or imperfect ohmic back-contact has been made. It has been shown that there is no excess capacitance that could be ascribed to the interface states or minority carrier at the intimate SBDs (that is, without interfacial layer) with the perfect ohmic back contact (low-resistance). It has been found that the excess capacitance is only measurable at SBDs with imperfect back contacts or with an interfacial layer which separates the interface states from the metal. It has been found that excess capacitance can be generated by varying the resistance or quality of the back-ohmic contact to the bulk semiconductor substrate, that is, the density of minority carriers that are injected by the Schottky contact depends sensitively on the properties of the ohmic back-contact. Again, it has been seen that the excess capacitance has appeared owing to the interface states plus minority carriers in MIS SBDs with imperfect back contacts. Thus, it has been concluded that the excess capacitance at nonideal Schottky contacts has been caused not only by the interface states but also by the minority carriers or by the interface states plus minority carriers due to the poor frontside or poor backside contacts. Thereby it has been experimentally shown that every forward bias C-f-plots with excess capacitance cannot be used to extract the results related to the interface states
Do oestrogen and progesterone receptors in anterior vaginal wall affect success of sling procedures?
No Abstract
Determination of the characteristic parameters of Sn/n-GaAs/Al-Ge Schottky diodes by a barrier height inhomogeneity model
A study on parameters of the Sn/n-GaAs Schottky barrier diode (SBD) fabricated on an n-type GaAs substrate has been made. The Sn/n-GaAs SBD has shown a nearly ideal behaviour with ideality factor and barrier height (BH) values of 1.081 and 0.642 eV, respectively, from the experimental forward-bias current-voltage (I-V) characteristics. A BH value of 0.724 eV has been obtained from the experimental reverse-bias capacitance-voltage (C-V) characteristics. An accurate theoretical modelling of the effect of the presence of inhomogeneities on the electron transport across the metal-semiconductor interface has been applied. This model attempts to explain abnormal experimental results obtained on 'real' Schottky diodes. Our results clearly demonstrate that the electron transport at the metal-semiconductor interface is significantly affected by low-barrier regions (patches). When the experimental data are described by the thermionic emission theory of inhomogeneous Schottky contacts, it has been concluded that both the experimental forward and reverse I-V characteristics and the difference between the values of the experimental I-V and C-V SBHs should be considered. An experimental BH difference of Delta = 0.082 V has been obtained for the Sn/n-GaAs SBD that is less than the critical value; therefore, it has been seen that the potential in front of the patch is not pinched off
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