Electrical and mechanical analysis of a segmented solar thermoelectric generator under non-uniform heat flux

Optimization of segmented solar thermoelectric generator for power output enhancement has been well researched however, the mechanical reliability study of such devices is usually neglected. In addition, assumed heat flux distribution or uniform flux distribution from solar concentrators is usually used for solar thermoelectric generator however, this is not accurate. Therefore, this study presents a detailed three-dimensional numerical investigation on the effect of non-uniform and uniform heat flux on the electrical and mechanical performance of segmented and non-segmented solar thermoelectric generator. Flux distribution from a compound parabolic concentrator is obtained by ray tracing using Lighttools software and COMSOL 5.4 Multiphysics software is used to perform the numerical study based on finite element method. Thermal stress analysis in a full-scale solar thermoelectric generator is presented and the effects of load resistance, solar radiation and cold side temperature on performance of solar thermoelectric generator is analysed. Results show that the power output of the segmented solar thermoelectric generators in Case 3, Case 4 and Case 5 increased by 44.07%, 59.12% and 37.9% respectively compared to that of Case 1 (bismuth telluride non-segmented solar TEG) at 13000W/m2. Results from this study will provide valuable guidance for segmented and non-segmented solar thermoelectric generator design

Transient and non-uniform heat flux effect on solar thermoelectric generator with phase change material

Transient and non-uniform heat flux from solar concentrators can affect the performance of solar thermoelectric generators, which generate electricity from concentrated solar radiation. Therefore, this paper presents a detailed three-dimensional study on the effect of transient and non-uniform heat flux on the performance of a solar thermoelectric generator (STEG). COMSOL 5.4 Multiphysics software is utilized for the numerical study while the non-uniform heat flux from a compound parabolic concentrator is obtained through ray tracing simulation using Lighttools software. Varying solar radiation under typical partly cloudy weather condition is utilized. Furthermore, phase change material (PCM) is used to reduce the effect of transient and non-uniform heat flux therefore; it is positioned at the top surface of the solar thermoelectric generator. A comparison between the performance of the STEG with and without PCM is presented, and a parametric study on the effect of PCM fins and PCM height on the STEG performance is carried out. Results show that the place of PCM on the top surface of the solar thermoelectric generator is an effective approach to provide a stable electrical performance form the STEG under varying weather conditions. Furthermore, results reveal the effectiveness of the phase change material in protecting the solar thermoelectric generator under highly concentrated solar radiation. This study will provide valuable design guidance for solar thermoelectric generators under varying weather conditions and with solar concentrators, which produce non-uniform heat flux

Impact of body mass index in therapeutic response for HER2 positive breast cancer treated with neoadjuvant targeted therapy: a multi-center study and meta-analysis

Abstract While overweight/obesity has become a major public health issue worldwide, any association between body mass index (BMI) and therapeutic response in neoadjuvant targeted therapy treated HER2 positive breast cancer patients remain unclear. The information from a total of four-hundred and ninety-one neoadjuvant targeted therapy treated HER2 positive breast cancer patients from four institutions were retrospectively collected. Univariate and multivariate logistic analysis was developed to determine the association between BMI and therapeutic response. A meta-analysis of published literature was then conducted to confirm the effect of overweight/obesity on pCR for patients treated with neoadjuvant targeted therapy. Restricted cubic spline (RCS) adjusted for confounding factors demonstrated a decrease pCR with increasing BMI (OR = 0.937, P = 0.045). Patients were then categorized into under/normal weight (n = 299) and overweight/obesity (n = 192). Overweight/obese patients were independently associated with a poor therapeutic response. In the subgroup analysis, a significant negative impact of overweight/obesity on pCR can be observed both in single-targeted (OR = 0.556; P = 0.02) and dual-targeted (OR = 0.392; P = 0.021) populations. Six eligible studies involving 984 neoadjuvant targeted therapy treated HER2 positive breast cancer patients were included in the meta-analysis. The meta-analysis also demonstrated that overweight/obesity was significantly associated with a poor response to neoadjuvant anti-HER2 therapy (OR = 0.68; P = 0.007). Our result show that overweight and obese HER2 positive breast cancer patients are less likely to achieve pCR after neoadjuvant targeted therapy

Additional file 1 of High leukocyte mitochondrial DNA copy number contributes to poor prognosis in breast cancer patients

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Additional file 3 of High leukocyte mitochondrial DNA copy number contributes to poor prognosis in breast cancer patients

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Additional file 2 of High leukocyte mitochondrial DNA copy number contributes to poor prognosis in breast cancer patients

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Additional file 4 of High leukocyte mitochondrial DNA copy number contributes to poor prognosis in breast cancer patients

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