Anterior Urethral Advancement in Repair of Hypospadias: A Modification of the Technique

Background/Purpose: Anterior Urethral advancement as one stage technique for hypospadias repair was first described by Ti – Shang Cheng in 1984. It was used for repair of distal and midpenile hypospadias. It was also used for treating secondary cases and urethral fistulae. Stricture, fistulae and ventral curvature were among the complications that faced surgeons on applying the original technique. Materials & Methods: In the period between March1997 and December 2008,140 patients with distal penile hypospadias or anterior urethral fistula were treated with anterior urethral advancement technique with certain modifications. Results: The usual complications of the technique (ventral curvature of the penis, urethral fistula and meatal stenosis) were avoided. Conclusion: This study represents certain modifications that helped to a great extent in improving the results and prevented stricture and fistula formation. Index Word: Hypospadias, fistula, urethral advancemen

Improvement of Gas Turbine Performance Using Multi-Stage Inlet Air Cooling System

Gas turbines play a significant role as an energy source if it has been designed according to the ISO operating conditions taking into consideration the operating conditions varied with the variation of the ambient conditions. This work aims to determine the effect of many parameters like the temperature at the compressor inlet, relative humidity, pressure ratios, and polytropic efficiency on each component of gas turbine performance (compressor, combustion chamber, and turbine). In this work, the Engineering Equation Solver (EES) software is used to calculate exergy destruction, net power, and all efficiencies (1st law and 2nd efficiency). After that, the validation of the code generated through EES software is performed using the actual performance data from the Heliopolis gas turbine power plant 25 MW. model, (GE GT-TM) made by GE. The results show the performance of the overall gas turbine behaves with and without a multi-stage cooling system.  In addition, the effect of using the new inlet air cooling system on the gas turbine performance improvement under different conditions is determined. It is worth mentioning that the maximum power output increase is about 14.3% at the maximum ambient temperature (313oK). While the change of the 1st low efficiency and the 2nd low efficiency are so small it could be neglected. Also, the results illustrate that first and second law efficiencies provide quantitative and qualitative compressor performance assessments. The present multi-stage cooling system reduces the back-period cost if it uses a chiller system. Adding a chilling system before the fogging cooling system reflects the downsizing of the chilling system. This means low initial capital investment costs and low total annual costs. In addition, the multi-stage cooling system capital cost will be cashback during the first year regarding recovered power pric

Two-Port Versus Three-Port Laparoscopic Appendectomy In Children

Background/Purpose: Laparoscopic appendectomy is the routine technique for management of acute appendicitis in children in many centers. In this study, the classic three-port technique is compared to the two-port technique in the noncomplicated non-difficult acute appendicitis. Materials & Methods: This is a retrospective study of the cases of non-complicated acute appendicitis treated laparoscopically between June 2003 and June 2009. Cases treated by the two-and three -port techniques were compared regarding the operative duration, operative and postoperative complications and the length of hospital stay. Results: During the study period, 85 children (45 males and 40 females) had laparoscopic appendectomy for acute noncomplicated appendicitis; 48 children by the Three-port technique (group I) and 37 children by the Two-port technique (group II).The mean age was 9.7 years (range 4 – 13). The mean operative duration was 40 minutes (range 30-70) in group I and 25 minutes in group II (range 17-35). Operative bleeding occurred in 9 cases (19%) (group I) and 8 cases (22%) group II, operative rupture of the appendix in 1(2%) , Port site infection (redness or discharge) in 3 (6%) in group I and none in group II, Postoperative ileus ( > 48 hours) 3 (6%) in group I and 1(2.7%) in group II. The mean length of hospital stay was 2.3 days in group I and 2 days in group II. Three cases in group II were converted to total laparoscopic appendectomy because of residual long stump (conversion rate 8%). Conclusion: The Two-port laparoscopic appendectomy had less operative duration and length of hospital stay than the threeport technique in non-complicated non-difficult acute appendicitis in children. However, the operative and post operative complications were almost the same.Index Word: Laparoscopy, appendectomy

Unveiling the role of carbon defects in the exceptional narrowing of m-ZrO2 bandgap for enhanced photoelectrochemical water splitting performance

The development of efficient photoelectrodes via defect engineering of wide-band gap metal oxides has been the prime focus for many years. Specifically, the effect of carbon defects in wide-band gap metal oxides on their performance in photoelectrochemical (PEC) applications raised numerous controversies and still elusive. Herein, the effect of various carbon defects in m-ZrO2 was investigated using the density functional theory to probe the thermodynamic, electronic, and optical properties of the defective structures against pristine m-ZrO2. The defect formation energies revealed that elevating the temperature promotes and facilitates the formation of carbon defects. Moreover, the binding energies confirmed the stability of all studied complex carbon defects. Furthermore, the band edge positions against the redox potentials of water species revealed that all the studied defective structures can serve as photoanodes for water splitting. Additionally, CO3c (carbon atom substituted O3c site) was the only defective structure that exhibited slight straddling of the redox potentials of water. Importantly, all investigated defective structures enhanced light absorption with different optical activities. Finally, CO3cVO3c (carbon atom substituted O3c associated with O3c vacancy) defective m-ZrO2 enjoyed low direct band gap (1.9 eV), low defect formation energy, low exciton binding energy, high mobility of charge carriers, fast charge transfer, and low recombination rate. Concurrently, its optical properties were exceptional in terms of high absorption, low reflectivity and improved static dielectric constant. Hence, the study recommends CO3cVO3c defective m-ZrO2 as the leading candidate to serve as a photoanode for PEC applications

THEEFFECT OF DIPEPTIDYL PEPTIDASE-4 INHIBITORS ON CARDIOVASCULAR DISEASE RISK IN TYPE 2 DIABETES MELLITUS

Objective: The aim of this study was is to investigate the proposed beneficial cardiovascular effects of a novel class of antidiabetic drugs named; dipeptidyl peptidase 4 inhibitors. In this study, we compared the effect of using add-on therapy of vildagliptin (dipeptidyl peptidase-4 inhibitor; DPP-4i) and gliclazide (sulphonylurea; SU) to that when using gliclazide monotherapy in patients with type 2 diabetes mellitus (T2DM) and acute coronary syndrome (ACS) on different cardiovascular outcomes.Methods: A total of 60 patients diagnosed with T2DM, and ACS were randomly recruited into two treatment groups each of 30 patients to receive either gliclazide monotherapy (SU) or vildagliptin (DPP4i)+gliclazide (SU) add-on therapy, administered in a double-blind fashion. Outpatient visits were scheduled at 3, 6, and 12 mo where patient was reevaluated for cardiovascular (CV) outcomes and followed up for any arising cardiovascular complication.Results: The vildagliptin (DPP4i) plus gliclazide (SU) add-on therapy group have significantly shown more improved glycemic control, lipid profile and ventricular performance compared to gliclazide (SU) monotherapy group with p values<0.05.Conclusion: Vildagliptin as a DPP4i provides favourable cardiovascular effects beyond glucose control. Yet, its long-term safety and efficacy data still needs further investigations

A method to suppress dielectric breakdowns in liquid argon ionization detectors for cathode to ground distances of several millimeters

We present a method to reach electric field intensity as high as 400 kV/cm in liquid argon for cathode-ground distances of several millimeters. This can be achieved by suppressing field emission from the cathode, overcoming limitations that we reported earlier