929 research outputs found
One and two dimensional tunnel junction arrays in weak Coulomb blockade regime-absolute accuracy in thermometry
We have investigated one and two dimensional (1D and 2D) arrays of tunnel
junctions in partial Coulomb blockade regime. The absolute accuracy of the
Coulomb blockade thermometer is influenced by the external impedance of the
array, which is not the same in the different topologies of 1D and 2D arrays.
We demonstrate, both by experiment and by theoretical calculations in simple
geometries, that the 1D structures are better in this respect. Yet in both 1D
and 2D, the influence of the environment can be made arbitrarily small by
making the array sufficiently large.Comment: 11 pages, 3 figure
Origin of the hysteresis in bilayer 2D systems in the quantum Hall regime
The hysteresis observed in the magnetoresistance of bilayer 2D systems in the
quantum Hall regime is generally attributed to the long time constant for
charge transfer between the 2D systems due to the very low conductivity of the
quantum Hall bulk states. We report electrometry measurements of a bilayer 2D
system that demonstrate that the hysteresis is instead due to non-equilibrium
induced current. This finding is consistent with magnetometry and electrometry
measurements of single 2D systems, and has important ramifications for
understanding hysteresis in bilayer 2D systems.Comment: 4 pages, 3 figs. Accepted for publication in PR
Electrometry using the quantum Hall effect in a bilayer 2D electron system
We discuss the development of a sensitive electrometer that utilizes a
two-dimensional electron gas (2DEG) in the quantum Hall regime. As a
demonstration, we measure the evolution of the Landau levels in a second,
nearby 2DEG as the applied perpendicular magnetic field is changed, and extract
an effective mass for electrons in GaAs that agrees within experimental error
with previous measurements.Comment: 3.5 pages, 3 figures, submitted to APL
Paternity, erectile function, and health-related quality of life in patients operated for pediatric testicular torsion
Introduction Spermatic cord torsion (SCT) may lead to organ loss and can potentially influence fertility. Long-term effects of SCT are not fully investigated. Objective The purpose was to evaluate paternity rates in adults who have had SCT in childhood and to compare the results to those of a control population. The secondary purposes were to compare paternity rates after testis-preserving surgery with those after orchiectomy and to evaluate erectile function and health-related quality of life (HRQoL). Study design Questionnaires concerning paternity, erectile function (International Index of Erectile Function [IIEF]-5 questionnaire), and HRQoL (15D questionnaire) were mailed to 74 men who had been treated for SCT and to 92 controls treated for testicular appendage torsion in 1977-1995 and who were currently older than 30 years. Results Thirty-five of the 74 (47%) patients with SCT and 58 of the 92 (63%) controls responded. A same-aged control was selected for each patient with SCT. The median age at investigation was 41 (interquatile range [IQR]: 36 to 46) years in the SCT group and 41 (IQR: 38 to 46) years in the control group (p = 0.81). The paternity rate was 23 of 35 (66%) in the SCT group and 26 of 34 (76%) in the control group (p = 0.43). Nine percent of patients and controls suffered from infertility. Of the 30- to 50-year-old patients with SCT, 9 of 16 (56%) had children after orchiectomy, and 13 of 16 (81%), after detorsion (p = 0.25). Significant or moderate erectile dysfunction (IIEF-5 total score Discussion Paternity, erectile function, or HRQoL was not impaired in the general level in the patients with SCT in comparison with controls. Both the modes of treatment, orchiectomy or detorsion, had no significant impact on the results. However, the results cannot be generalized to the individual level. The limitations were a small sample size and inability to investigate maternal factors to the paternity. However, the results are encouraging for the patients and families. Conclusion Paternity rate and HRQoL were similar in patients with SCT and controls. The type of surgery (orchiectomy vs. detorsion) did not affect paternity rates statistically. Moderate or significant erectile dysfunction was rare in both groups.Peer reviewe
Modelling of fluid flow phenomena in Peirce-Smith copper converters and analysis of combined blowing concept
This investigation consists of a numerical and physical modelling exercise on flow patterns, mixing, solid-liquid mass transfer, and slag-matte phase distribution in a 0.2-scale cold model of an industrial Peirce-Smith converter (PSC). Water, kerosene, air, and sintered benzoic acid compacts were used to simulate matte, slag, injected gas, and solid additions into the PSC. The 2D and 3D numerical simulations were carried out using volume of fluid (VOF) and realizable k-ε (RKE) turbulence models to account for the multiphase and turbulence nature of the flow respectively. These models were implemented using the commercial computational fluid dynamics numerical code FLUENT. Numerical and physical simulations were able to predict, in agreement, the mixing and dispersion characteristics of the system in relation to various blowing conditions. Measurement of mass transfer indicated that fluid flow in the PSC is stratified. Blowing configurations and slag volume both had significant effects on mixing propagation, wave formation, and splashing. As a potential process alternative to increase conversion efficiency, we propose a combined blowing configuration using top lance and lateral nozzles. The numerical simulations were conducted on combined as well as lateral blowing conditions, and the results of the combined concept are encouraging
Sexual Function, Fertility and Quality of Life after Modern Treatment of Anorectal Malformations
Purpose: Sexual dysfunction and impaired quality of life due to fecal incontinence are common after classic operations for anorectal malformations. We hypothesized that modern repairs may result in improved outcomes. Materials and Methods: Following ethical approval for this single institution cross-sectional study, all patients 16 years or older treated for rectourethral, vestibular or perineal fistula from 1983 onward were sent detailed postal questionnaires on sexual function and quality of life. Each respondent was age and gender matched to 3 controls randomly selected from the general population. Penoscrotal/gynecologic abnormalities were obtained from the records. Results: A total of 41 patients (62%) with a median age of 22 years participated in the study. Of the patients 20 were males with rectourethral fistula (prostatic in 60%), 10 were females with vestibular/perineal fistula and 11 were males with low malformations. Although experience of sexual relationships and orgasmic function were reported in comparable proportions to controls, age at coital debut was significantly delayed in all groups of patients (p Conclusions: While erectile and orgasmic function appear preserved after sagittal repair, further evaluation of fertility issues in males with rectourethral fistula is indicated. Larger multicenter studies are needed to confirm our findings.Peer reviewe
تطوير الكتاب التعليمي لمهارة الكلام بالخريطة الذهنية
كان معهد الرسالة العصري المبرمج العالمي جعل اللغة العربية كلغة رسمية حيث تجب الطالبات استخدامها كل يوم. وفي تطبيقها واجه المعهد بعض المشكلات، منها: 1) إن الطالبات الجديدات مطالبة إلى تكيف اللغة مع الطالبات القدماء المستوعبات باللغة العربية بأسرع مايمكن. 2) كان الكتاب التعليمي لمهارة الكلام المستخدم في هذا المعهد مازال تقليديا. وجاءت الباحثة بالخريطة الذهنية لحل هذه المشكلة. لأن الخريطة الذهنية هي من الطريقة الأسهل لتخزين المعلومات في مخ، واستخراجها منه، إنها وسيلة إبداعية فعالة لتدوين الملاحظات التي "ترسم الخرائط" لأفكار. وإن الأهداف لهذا البحث هي: 1) لفهم كيفية تطوير الكتاب التعلمي لمهارة الكلام بالخريطة الذهنية. 2) لفهم موصفات الكتاب التعلمي لمهارة الكلام بالخريطة الذهنية. 3) لفهم مدى فعالية الكتاب التعلمي لمهارة الكلام بالخريطة الذهنية.
استخدمت الباحثة منهج البحث والتطوير لكتابة هذا البحث. وهو طريقة البحث المستخدمة للحصول على نتائج معينة وتجربة فعالة. ولاتمام هذا البحث استخدمت الباحثة الخطوات لبورج وجال (Borg and Gall).
ونتائج هذا البحث: 1) يتم هذا التطوير بالخطوات: الدراسة المبدئية وجمع البيانات وتصميم المنتج وتصديق الخبراء وتعديل المنتج وتجربة الصلاحية وتعديل المنتج وتجربة الفعالية وتنقيح المنتج ونشر الكتاب. 2) ومن موصفات هذا الكتاب التعليمي: "تكلم لنا". ويحتوي الكتاب على المفردات الأساسية، العبارات المهمة، الحوارات، والتدريبات. 3) إن استخدام الكتاب التعليمي لمهارة الكلام بالخريطة الذهنية فعالة لترقية مهارة الكلام وتحصل نتيجة على 10,4. بمعنى لهذا الكتاب التعليمي المطور أثر كبير (Significant) أي فعالة لنجاح الطالبات في تعلم مهارة الكلام
Disorders of sex development : timing of diagnosis and management in a single large tertiary center
Background: We describe the phenotypic spectrum and timing of diagnosis and management in a large series of patients with disorders of sexual development (DSD) treated in a single pediatric tertiary center. Methods: DSD patients who had visited our tertiary center during the survey period (between 2004 and 2014) were identified based on an ICD-10 inquiry, and their phenotypic and molecular genetic findings were recorded from patient charts. Results: Among the 550 DSD patients, 53.3% had 46,XY DSD; 37.1% had sex chromosome DSD and 9.6% had 46,XX DSD. The most common diagnoses were Turner syndrome (19.8%, diagnosed at the mean age of 4.7 +/- 5.5 years), Klinefelter syndrome (14.5%, 6.8 +/- 6.2 years) and bilateral cryptorchidism (23.1%). Very few patients with 46,XY DSD (7%) or 46,XX DSD (21%) had molecular genetic diagnosis. The yearly rate of DSD diagnoses remained stable over the survey period. After the release of the Nordic consensus on the management of undescended testes, the age at surgery for bilateral cryptorchidism declined significantly (P <0.001). Conclusions: Our results show that (i) Turner syndrome and Klinefelter syndrome, the most frequent single DSD diagnoses, are still diagnosed relatively late; (ii) a temporal shift was observed in the management of bilateral cryptorchidism, which may favorably influence patients' adulthood semen quality and (iii) next-generation sequencing methods are not fully employed in the diagnostics of DSD patients.Peer reviewe
Lower urinary tract symptoms and sexual functions after endorectal pull-through for Hirschsprung disease : controlled long-term outcomes
Background/purpose: To define the prevalence of lower urinary tract symptoms (LUTS) and outcomes for sexual function after endorectal pull-through (EPT) for Hirschsprung disease (HD) compared to controls. To date, similar controlled studies are lacking. Methods: Patients aged = 4 years (n= 123) operated on forHDat our center between 1987 and 2011were invited to answer questionnaires on LUTS and sexual function (aged = 16 years). Patients with an intellectual disability and patients with a definitive endostomy were excluded. Patients were matched to three controls and also invited to a clinical follow-up for urological investigations including urine flow measurement, renal tract ultrasound, and urinalysis. Results: Altogether, 59 responses concerning LUTS and 24 responses concerning sexual functions were analyzed. No significant differences were demonstrated in the overall prevalence of LUTS between patients (67%) and controls (80%), nor in the prevalence of frequent LUTS (14% vs. 16%; P = NS for both). One patient (2%) had a urethral stricture after laparotomy-assisted EPT. Male patients reported sexual satisfaction and erectile function similar to controls (P N 0.10). Female patients were currently less in stable relationships compared to controls (25% vs. 83%, P= 0.005). Conclusions: Our results support the safety of EPT in patientswith HDwith regard to preservation of the integrity and functioning of the genitourinary tract. (C) 2017 Elsevier Inc. All rights reserved.Peer reviewe
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