UV photodetectors based on W-doped ZnO thin films.

W-doped ZnO thin films deposited on Si substrates with (100) orientation by sol-gel spin coating method at temperature 500 °C. W/Zn atomic ratio varies from 0% to 4%. Then, the UV detection performance analysis ofp-nheterojunction UV photodetectors based on W-doped ZnO/Si is analyzed. The current-voltage curves of W-doped ZnO/Si are investigated in dark and exhibit diode-like rectifying behavior. Among doped ZnO/Si, sample with atomic ratio of W/Zn = 2% is the best candidate to study photodetector characteristics in UV range. The resulting device exhibits a rectification ratioRRof 5587 at ±5 V, a higher responsivity of 3.84 A W-1and a photosensitivity value of 34 at 365 nm under 0.5 mW cm-2. The experimental findings reveal that the UV detection performance of the heterojunction-based photodetectors strongly dependent on the properties of metal oxide layer. The main goal of this work is to investigate the effect of W doping on the performance of ZnO/Si based photodetectors. Based on our results, it is observed that 2 at% of W dopant is the optimum amount of doping for high performance photodetector of ZnO:W/Si heterojunction thanks to the suppressed recombination ratio and enhanced carrier separation properties in the depletion zone.

The role of urodynamic studies in the diagnosis and treatment of patients with spina bifida.

AIM: Spina bifida (SB) is a congenital deformity that is frequently seen in infancy. Surgical treatment and clinical follow-up of patients with the diagnosis of SB are important to provide education to the patients and their relatives, to increase patient survival, to ensure that they have a more comfortable life. Neuro-urological problems are highly important for the patients in terms of both social and medical. MATERIALS AND METHODS: The medical records of patients who underwent surgery for SB and tethered cord syndrome at our clinic in the past year were retrospectively evaluated. The results of urodynamic studies of the patients were evaluated. The results of patients who underwent control urodynamic studies during the follow-up period were compared with the previous results, and their clinical courses were determined. RESULTS: The most frequent urodynamic changes in patients were hyperactive detrusor activity and detrusor sphincter dyssynergy preoperatively. CONCLUSION: A significant improvement was observed when the results of postoperative urodynamic studies were evaluated in patients who underwent surgery for tethered cord.

Botulinum injection is useless on fibrotic neuropathic bladders.

OBJECTIVE: Studies on the use of intradetrusor botulinum toxin A injection for children with neuropathic bladders are insufficient and the results are controversial. The aim of the present study was to evaluate the effect of intradetrusor botulinum toxin A injection for children with neuropathic bladders that are resistant to anticholinergic treatment, and to reveal any criteria indicating treatment success. PATIENTS/METHODS: Hospital records were reviewed of 16 children with neuropathic bladders due to myelomeningocele, and who had botulinum toxin A injections between 2007 and 2010. Botulinum toxin A (10 units/kg) was injected endoscopically into various sites of the detrusor, except the trigone. The success was defined as complete dryness between clean intermittent catheterizations. Urodynamic studies before and after the application were evaluated and parameters, including bladder capacity (measured/expected) and compliance, were also analyzed. Reviewing the results, patients were then classified into two groups: as having fibrotic bladders (noncompliant, acontractile bladders with high pressures) or overactive bladders. Urodynamic findings and therapy success were then compared between the groups. RESULTS: A total of 19 injections, including repeat injections in three patients, were performed. Results of the 16 initial injections were evaluated. Nine patients had detrusor overactivity, and five out of nine (56%) applications in this group resulted in complete dryness between clean intermittent catheterizations. In bladders with typical detrusor overactivity, there was a significant increase in both the capacity (from 0.53 to 0.74) and compliance (from 4.7 to 8.6 ml/cm H2O). Looking at the seven patients that displayed fibrotic bladders with very low compliance and no contraction at all, none of them presented with notable clinical improvement from injections. Comparing the urodynamic findings, there was no significant difference in compliance (3.1 ml/cm H2O before and 3.5 ml/cm H2O after) and bladder capacity (0.58 before and 0.52 after the treatment) in the fibrotic bladders. DISCUSSION: Despite its worldwide usage and FDA approval, studies on the effectiveness of botulinumtoxin A on neuropathic bladders in children are controversial. There are now numerous studies attesting to the good results of BoNTA in neuropathic detrusor overactivity; however, only scarce reports comment on the specific features of the disease process among patients and reasons for failure in some. In our study, reviewing the urodynamic findings carefully, it was observed that the patients who did not respond to injections were the ones with no contractions, despite high pressures and low compliance. Therefore, describing the indications of BoNTA as neuropathic detrusor overactivity and urinary incontinence despite anticholinergic medications may lead to mistreatment of patients in the decompensated phase of a hyper-reflexive detrusor. Pretreatment urodynamic evaluation might be a good indicator, without biopsies, of estimating the degree of fibrosis and the patients who will benefit from the injection. CONCLUSION: Botulinum toxin A injection in the neuropathic bladder of myelomeningocele patients was found to be ineffective if the detrusor was fibrotic, of low compliance and had lost contractility. Urodynamic findings should be carefully analyzed in order to select appropriate patients that may benefit from Botulinum injection.

Analysis of 33 pediatric trauma victims in the 1999 Marmara, Turkey earthquake.

BACKGROUND/PURPOSE: The Marmara earthquake, which destroyed more than 150,000 buildings and caused 15,000 deaths and 40,000 casualties, resembled the Hanshin-Awaji earthquake in many respects. Previous reports from similar disasters from several centres have not addressed trauma in the pediatric age group. The aim of this study was to analyze the clinical and laboratory data of pediatric trauma patients referred to a tertiary center after the 1999 Marmara earthquake. METHODS: The medical records of 33 injured children, aged from 14 days to 16 years, were reviewed retrospectively. The time spent buried under rubble, type of injury, treatment given, complications, laboratory data, and development of acute renal failure (ARF) were noted. Patients in whom ARF developed were treated with a standard regimen of fluid replacement, alkalinization, and diuretics. Limbs with crush injuries were managed as conservatively as possible. RESULTS: All except 3 cases were evacuated from under the debris of collapsed buildings after 1 to 110 (mean, 30.04 +/- 6.48) hours. Seventy-eight percent were transported to our center within the first 3 days. Crush injury (CI) was present in 15 cases, and in 10 of them ARF had already developed by admission. Although serum levels of creatinine were elevated (1.2 to 5 mg/dL) in all cases with ARF, hyperkalemia was observed in only 4. The mean serum creatinine kinase (CK) level of cases with crush syndrome (CS) was 6,040 +/- 4,158 U/L. No significant correlations were detected between the development of CS, age, the time spent under the rubble, the time before admission, or the number of crushed extremities. CONCLUSIONS: CI and CS were the most common entities encountered among our pediatric patients after the 1999 Marmara earthquake. The high incidence of ARF indicates the importance of medical management of this age group during rescue. Because neither laboratory data nor clinical findings predicted CS in our patients, we recommend close observation and monitoring of children with CI for the development of ARF.