Background: The arterial switch operation [ASO] is the surgical procedure of choice for correction of the TGA. This is one of the most complex cardiac surgeries, with coronary artery transfer being the most important factor determining the success of the surgery. Objectives: This study aims to investigate the outcomes of ASO operated by a single surgeon and assess the accuracy of echocardiography in identifying the coronary artery pattern before the ASO, this may lead to a better familiarization with the ASO. Methods: A retrospective study was conducted by operative and postoperative case note review of 125 patients from March 2015 to 2018. We assessed the outcomes of the arterial switch operation. Concomitant defects as atrial septal defects, patent ductus arteriosus and small ventricular septal defects were defined as the simple TGA and other defects were defined as the complex TGA. Coronary artery pattern determination by echocardiography prior to the surgery and during the operation was investigated, as well. 30-day mortality, post-operative neurologic complications, cardiac anatomic complications, arrhythmia, plasma lactate level and cardiopulmonary bypass time [CPB time] during the surgery were recorded. Results: The mean age and weight of the patients were 29. 09 (1-180) days and 3506. 48 (2400-9700) grams. Most of the patients (64%) were male. 105 (84%) of the patients had simple and 20 (16%) had complex TGA. Unusual coronary pattern during echocardiography was observed in 17 (13. 6%) subjects and unusual coronary pattern during the operation was observed in 7 (5. 6%) patients. The incidence of the major anatomical lesions was not significant. 20 (16%) had neurologic complications, including seizure in 14 (11. 2%) patients, brain hemorrhage was found in 5 (4%) patients, as well as chorea and wrist drop in the remaining patients. Post-operative arrhythmia was observed in 16 (12. 8%) patients. The mortality rate was 4% (5 patients). The CPB time was 202. 73, 36. 99 minutes. Conclusions: Our post-operative results of the ASO indicate excellent results. This signifies high experience and knowledge regarding this surgery.

In this paper, a single switch transformer-less DC-DC converter with continuous input current for photovoltaic applications is proposed. The suggested configuration utilizes a CL1C2D2 structure to achieve a high voltage gain and alleviate voltage pressure on the semiconductor components. This design enables a significant increase in voltage output with a minimal turns ratio, leading to reduced size, weight, and cost of the converter system. The reduction in turns ratio of the coupled inductor results in lowered voltage stress on the semiconductor elements. Additionally, employing just one power switch in the converter simplifies control and reduces expenses. With its continuous input current, this converter is particularly well-suited for integration in photovoltaic systems. Simulation results conducted using PSCAD/EMTDC software validate the efficacy of the proposed power converter. Furthermore, the maximum power output of the photovoltaic module through an MPPT (Maximum Power Point Tracking) controller under varying irradiance levels is determined, and simulations are executed using PSCAD/EMTDC.

In this paper, a new transformerless buck-boost converter based on ZETA converter is introduced. The proposed converter has the ZETA converter advantages such as, buck-boost capability and input to output DC insulation. The suggested converter voltage gain is higher than the classic ZETA converter. In the presented converter, only one main switch is utilized. The proposed converter offers low voltage stress of the switch; therefore, the low on-state resistance of the main switch can be selected to decrease losses of the switch. The presented converter topology is simple; hence, the control of the converter is simple. The mathematical analyses of the proposed converter are given. The experimental results confirm the correctness of the analysis.