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.

The conventional boost and buck boost converter have low voltage gain. The voltage gain of the conventional converters is limited considering the issues such as parasitic resistance and because of this issues, high step up dc-dc converter must be used. In this paper, new transformerless high step-up buck boost and boost converters with low stress on the switch are proposed. In this converters only one active switch are used, which makes the control scheme simple as well as reducing the switching power loss. The voltage gain of the proposed converters is higher than the conventional boost and buck boost converters. The proposed converters expand the continues conduction mode (CCM) operation region. Proposed converters have low voltage stress on the active switch, low conduction loss and high efficiency. The proposed converters can be operated in the continuous conduction mode (CCM) and the discontinuous conduction mode (DCM). In this paper, different operation modes of the proposed converter, calculation of the voltage gain, the currents that flow through the components and efficiency are provided. To prove the correct operation of the proposed converters, simulation results in PSCAD software are provided.

Multilevel inverters are a new generation of DC-AC converters at medium and high voltage and power levels. These converters have made great strides in the use of industrial applications compared to conventional two-level inverters due to lower harmonic distortion, filter size, EMI and dv/dt. Besides these merits, some disadvantages can be mentioned such as more power electronics devices and complex control structure. In order to resolve these disadvantages, this paper proposes a new switch-diode based multilevel inverter. This topology is presented with the aim of reducing the number of switches and drivers that are able to modularly increase the number of output levels. The proposed structure has been improved to achieve a higher number of output voltage levels relative to the number of switches, drivers and DC voltage source. To confirm the superiority of the proposed structure, a detailed comparison has been performed with other MLI topologies. In this paper, the nearest level modulation technique is used to generate the output voltage and is simulated in Matlab/Simulink environment. Finally, experimental results are presented to confirm the performance of the designed topology.

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.

Background and aim: It is possible to use light sources suxh as lasers to destruct melanosomes and treat pigmented skin lesions. One of the most commonly used laser systems is Q switched ruby laser with a wave-length of 694 nm. This study was performed to evaluate the efficacy of the Q switched ruby laser in the treatment of pigmented skin lesions including lentigines (simplex or solar) and café-au-lait macules.Materials and Methods: After physical examination for ruling out the possibility of malignancy by two dermatologists, patients were treated with Q switched ruby laser. Response to treatment was categorized in four groups of equal interval according to the 0-100% lesion lightening. Results: Ninetyy patients including 81 patients with solar lentigo and 9 cases of lentigo simplex were recruited into this study. Mean standard deviation (SD) of the number of treatment sessions for solar lentigo and lentigo simplex cases were 1.0 0.5 and 3.6 1.3, respectively. Although the mean of sessions was increased in darker skin types, there was no statistically significant difference between different skin types (p=0.335). In addition, there was no significant relation between mean treatment sessions and location of the lesions (p=0.685). Cure rate was 100% in all lentigo cases and after a mean SD of 8.7 2.3 months follow up there was no recurrence. Also, there was neither pigmentary change nor folliculitis during treatment. In 7 cases with cafe-au-Iait macules, the mean SD score of improvement was 2.4 0.8, which was achieved after 3.1 0.4 treatment sessions. In 6 cases whom were followed up for 10.2 3.1 months, despite primary disappearance, recurrence of café-au-lait macules was observed.Conclusion: It seems Q switched ruby laser is an appropriate method for treatment of lentiginous lesions in caucasians with Fitzpatrick's skin types II to IV.