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Author(s): Anju Joy (corresponding author) [1]; Aswin Kumar [1]; Neelima Radhakrishnan [2] INTRODUCTION Renal cell carcinoma is one of the most lethal tumors of the urologic system and has high [...], Renal cell carcinoma is one of the most lethal tumors of the urologic system and has high metastatic potential. The usual sites of metastasis are lung, bone, liver adrenal, lymph node, and brain. Thumb and oral cavity metastasis are unusual sites of metastasis. This case report describes two cases reported with unusual thumb and oral cavity metastasis. Patients with acral and oral metastasis are often misdiagnosed as benign inflammatory disease and treatment initiation is often delayed. This case report helps in drawing the attention that such lesions can be metastatic also. Keywords: Acral metastasis, metastasis, oral metastasis, renal cell carcinoma

Background: Ewing's sarcoma (EWS) is an aggressive small round cell tumor, affecting bone and soft tissues and is mostly seen in childhood and second decade of life. EWS accounts for 10-12% of bone tumors in more than 15 years age group and is even rarer after 40 years of age. Materials and Methods: This retrospective analysis was conducted among patients aged more than 15 years with histologically proven EWS. Results: Among 240 cases of EWS treated at our center during 2001-2010, 130 (54%) were more than 15 years of age. The median age was 20 years with a male: female ratio of 2.4:1. Ninety percent had skeletal EWS, 10% had extra skeletal EWS, and 37% patients were metastatic at presentation. Eighty-two received curative treatment with chemotherapy (vincristine, doxorubicin, cyclophosphamide, ifosfamide, etoposide (VAC/IE)) along with local treatment, radiotherapy (RT) in 61, surgery alone in seven, and RT plus surgery in 14. Two- and 5-year overall survival (OS) was 43.3% and 25.5%, respectively, for the entire series. The OS for the non-metastatic group was 63.2% at 2 years and 36.5% at 5 years, and the progression free survival was 53.7% at 2 years and 37.8% at 5 years. High lactate dehydrogenase was found to be a significant poor prognostic factor (P = 0.001). Median OS for localized central EWS was 49.2 months and that for peripheral EWS was 24 months. Patients more than 20 years of age with non-metastatic disease had better OS compared to those with 15-20 years of age. Conclusion: Treatment of EWS requires a multidisciplinary approach with radical surgery and/or radiation to control local disease and multiagent chemotherapy to control systemic disease. Long-term follow-up is essential because of disease relapse and treatment-related complications. Keywords: Ewing's sarcoma, extraskeletal Ewing's sarcoma, skeletal Ewing's sarcoma, VAC/IE, Author(s): Geetha Narayanan (corresponding author) [1]; Lakshmi H. Kamala [1]; Sreejith G. Nair [1]; Prakash N. Purushothaman [1]; Aswin Kumar [2]; Jayasree Kattoor [3] INTRODUCTION Ewing's sarcoma (EWS) is an [...]

An onboard charger segment is currently dominated by two-stage charger designs, which suffer from drawbacks such as large size, low efficiency due to a high component count, elevated cost, and intricate controller requirements. To address these challenges, this work explores the implementation of an isolated bridgeless version of a modified single-ended primary inductor converter (SEPIC). This innovative approach aims to develop a single-stage, high-power factor battery charger tailored for light electric vehicles (LEVs). In addition to achieving high power factor operation, maintaining continuous input and output currents, and enabling high voltage conversion ratios, this charger utilizing modified SEPIC converter is specifically engineered to alleviate voltage stress on power switches within the converter circuit. This charger operates in discontinuous conduction mode (DCM), offering several notable advantages. These include inherent power factor correction capability, reduced control effort, minimized size of magnetic components, and fewer sensors, ultimately leading to a significant reduction in overall implementation cost. This article aims to validate charger's operation, elaborate on design of its components, outline control algorithm design, and demonstrate performance of both components and control logic through test results from hardware prototype developed, for a power level of 500 W.

This article presents a modified single-ended primary inductance converter based single-stage ac–dc converter designed specifically for low voltage electric vehicles (LVEVs) charger applications. The rectifier showcases in this article demonstrates a high-step down buck gain, making it ideal for charging low-voltage battery packs commonly found in LVEVs. By utilizing a bridgeless structure at the input side with simultaneously operated switches, the converter reduces control complexity and eliminates the need for input voltage polarity sensing, a requirement in conventional continuous inductor current mode converters. The converter's extended step-down gain is achieved through switched-inductor structures, enabling it to deliver the required battery charging profile for low-voltage battery packs. Operating the inductors in discontinuous inductor current mode not only facilitates intrinsic power factor correction capabilities at the grid side but also reduces the size of magnetic components. DICM operation also provides zero-current turn-on for switches and zero-current turn-off capability for high-frequency diodes, thereby minimizing losses associated with diode reverse-recovery transitions. During testing on a proof-of-concept testbench at a power level of 450 W, the converter demonstrated a peak efficiency of 94.2% at rated power. In addition, the total harmonic distortion in input current was measured at 3.4%, showcasing a unity power factor and good power quality (PQ) indices at the grid. These results highlight the effectiveness of the converter in maintaining proper battery charging profiles while ensuring high efficiency and PQ standards in LVEV charging applications.

A single-switch modified SEPIC bridgeless coupled switched inductor-based charger, for charging applications of low voltage electric vehicles (LVEVs) is demonstrated in this work. Presented charger achieves higher step-down gain between the AC grid and the DC battery pack output without requirement of a step-down transformer, using a coupled switched inductor structure. The discontinuous inductor current mode (DICM) operation of charger reduces the magnetic volume, thus making it compact. The DICM operation adds advantages of inherent power factor correction (PFC) at the input side, without requirement of additional input sensing circuitry. Added to this, DICM operation facilitates zero current turn-on and zero-current turn off for switches and diodes in the charger, respectively, which reduces switching losses associated with high frequency components. Lastly, the design, operating modes and performance of charger is verified through development of a prototype and results obtained are presented in this work.