High-efficiency segmented thermoelectric power generation modules constructed from all skutterudites

Development of thermoelectric conversion technology for power generation can alleviate the demand for fossil energy and increase the efficiency of energy utilization. To achieve more efficient heat-to-electric conversion, it is desirable to maximize the figure of merit (zT) over a wide temperature range. Constructing a segmented thermoelectric device by serially connecting materials with high zT at different operating temperatures has been proven feasible. However, the issue of compatibility of different thermoelectric materials and the method of connecting different segments to ensure high interfacial stability remain unsolved. Herein, we demonstrate a full skutterudite-based segmented thermoelectric power generation module. The use of thermoelectric materials from the same parent avoids the difference in thermal expansion coefficients and compatibility factors and allows the preparation of thermoelectric junctions by a one-step sintering process. As a result, a high module efficiency of 10.4% is obtained owing to the rational design of the materials, device geometry, and interfaces and is the highest value among skutterudite-based modules reported so far

Interaction between magnetic moments and itinerant carriers in d0 ferromagnetic SiC

Elucidating the interaction between magnetic moments and itinerant carriers is an important step to spintronic applications. Here, we investigate magnetic and transport properties in d0 ferromagnetic SiC single crystals prepared by postimplantation pulsed laser annealing. Magnetic moments are contributed by the p states of carbon atoms, but their magnetic circular dichroism is different from that in semi-insulating SiC samples. The anomalous Hall effect and negative magnetoresistance indicate the influence of d0 spin order on free carriers. The ferromagnetism is relatively weak in N-implanted SiC compared with that in Al-implanted SiC after annealing. The results suggest that d0 magnetic moments and itinerant carriers can interact with each other, which will facilitate the development of SiC spintronic devices with d0 ferromagnetism.Comment: 20 pages, 5 figure

A new reference genome for Sorghum bicolor reveals high levels of sequence similarity between sweet and grain genotypes: implications for the genetics of sugar metabolism.

BackgroundThe process of crop domestication often consists of two stages: initial domestication, where the wild species is first cultivated by humans, followed by diversification, when the domesticated species are subsequently adapted to more environments and specialized uses. Selective pressure to increase sugar accumulation in certain varieties of the cereal crop Sorghum bicolor is an excellent example of the latter; this has resulted in pronounced phenotypic divergence between sweet and grain-type sorghums, but the genetic mechanisms underlying these differences remain poorly understood.ResultsHere we present a new reference genome based on an archetypal sweet sorghum line and compare it to the current grain sorghum reference, revealing a high rate of nonsynonymous and potential loss of function mutations, but few changes in gene content or overall genome structure. We also use comparative transcriptomics to highlight changes in gene expression correlated with high stalk sugar content and show that changes in the activity and possibly localization of transporters, along with the timing of sugar metabolism play a critical role in the sweet phenotype.ConclusionsThe high level of genomic similarity between sweet and grain sorghum reflects their historical relatedness, rather than their current phenotypic differences, but we find key changes in signaling molecules and transcriptional regulators that represent new candidates for understanding and improving sugar metabolism in this important crop

Bifurcations of Traveling Wave Solutions for the Coupled Higgs Field Equation

By using the bifurcation theory of dynamical systems, we study the coupled Higgs field equation and the existence of new solitary wave solutions, and uncountably infinite many periodic wave solutions are obtained. Under different parametric conditions, various sufficient conditions to guarantee the existence of the above solutions are given. All exact explicit parametric representations of the above waves are determined

Drone Assisted Robust Emergency Service Management for Elderly Chronic Disease

It is important to monitor the early screening of chronic diseases, predict the risk, and provide the comprehensive management of chronic diseases for the elderly. However, it is difficult to provide the robust and real-time emergency service for elderly chronic disease because of the complex social network and diversity of elderly chronic disease service. To address these issues, we design a new drone assisted robust emergency service system. We formulate the Drone assisted Management (DM) problem to minimize the total time cost of drone subject to all elderly chronic disease services which can be guaranteed exactly once by the drone under its energy constraint. Then, we propose the DRS algorithm to solve the DM problem. To provide the robust and real-time service, we further formulate the Charging driven Drone assisted Management (CDM) problem and present the CDRS algorithm to solve the CDM problem. Through the theoretical analysis and numerical simulation experiments, we demonstrate that DRS and CDRS can decrease the total time cost by 37.61% and increase the QoE by 112.80% through the designed system, respectively

Interleukin-8 transcripts in mononuclear cells determine impaired graft function after kidney transplantation

OBJECTIVE:Interleukin-8 (IL-8) has been associated with ischemia reperfusion injury after renal allograft transplantation. Impaired allograft function may cause major impact on patient morbidity and health care costs. We investigated whether transcript levels in mononuclear cells including IL-8 on the first postoperative day may be involved in immediate allograft dysfunction as defined by reduced relative change in plasma creatinine at the first postoperative day. METHODS:We performed a single center, prospective-cohort study of 113 patients receiving kidney transplants. Peripheral blood mononuclear cells were harvested within 24 hours after transplantation. Transcripts were measured using quantitative RT-PCR. RESULTS:Transcript levels of IL-8 and S100A8 were significantly lower in patients with relative change in plasma creatinine less than 10% at the first postoperative day. Receiver-operator characteristic curves showed that IL-8 predicted the relative change in plasma creatinine less than 10% (area under curve (AUC), 0.80; P = 0.0007). Multivariate analyses showed that lower IL-8 transcripts, longer time on dialysis, higher recipient body mass index and deceased donor type were associated with relative change in plasma creatinine at the first postoperative day less than 10%. CONCLUSION:Reduced levels of IL-8 transcripts in peripheral mononuclear cells predict immediate graft dysfunction and delayed graft function

Application of ALD-Al₂O₃ in CdS/CdTe Thin-Film Solar Cells

The application of thinner cadmium sulfide (CdS) window layer is a feasible approach to improve the performance of cadmium telluride (CdTe) thin film solar cells. However, the reduction of compactness and continuity of thinner CdS always deteriorates the device performance. In this work, transparent Al2O3 films with different thicknesses, deposited by using atomic layer deposition (ALD), were utilized as buffer layers between the front electrode transparent conductive oxide (TCO) and CdS layers to solve this problem, and then, thin-film solar cells with a structure of TCO/Al2O3/CdS/CdTe/BC/Ni were fabricated. The characteristics of the ALD-Al2O3 films were studied by UV–visible transmittance spectrum, Raman spectroscopy, and atomic force microscopy (AFM). The light and dark J–V performances of solar cells were also measured by specific instrumentations. The transmittance measurement conducted on the TCO/Al2O3 films verified that the transmittance of TCO/Al2O3 were comparable to that of single TCO layer, meaning that no extra absorption loss occurred when Al2O3 buffer layers were introduced into cells. Furthermore, due to the advantages of the ALD method, the ALD-Al2O3 buffer layers formed an extremely continuous and uniform coverage on the substrates to effectively fill and block the tiny leakage channels in CdS/CdTe polycrystalline films and improve the characteristics of the interface between TCO and CdS. However, as the thickness of alumina increased, the negative effects of cells were gradually exposed, especially the increase of the series resistance (Rs) and the more serious “roll-over„ phenomenon. Finally, the cell conversion efficiency (η) of more than 13.0% accompanied by optimized uniformity performances was successfully achieved corresponding to the 10 nm thick ALD-Al2O3 thin film

High glucose modifies transient receptor potential canonical type 6 channels via increased oxidative stress and syndecan-4 in human podocytes

Transient receptor potential canonical (TRPC) channels type 6 play an important role in the function of human podocytes. Diabetic nephropathy is characterized by altered TRPC6 expression and functions of podocytes. Thus, we hypothesized that high glucose modifies TRPC6 channels via increased oxidative stress and syndecan-4 (SDC-4) in human podocytes. Human podocytes were exposed to control conditions (5.6mmol/L d-glucose), high glucose (30mmol/L d-glucose or l-glucose), 100mumol/L peroxynitrite, or high glucose and the superoxide dismutase mimetic tempol (100mumol/L). TRPC6 and SDC-4 transcripts and protein expression were measured using RT-PCR and in-cell Western assay. Intracellular reactive oxygen species (ROS) and cytosolic calcium were measured using fluorescent dye techniques. High d-glucose increased TRPC6 transcripts to 8.66+/-4.08 (p<0.05) and TRPC6 protein expression to 1.44+/-0.07 (p<0.05) without altering SDC-4 transcripts or protein expression. The d-glucose induced increase of TRPC6 expression was blocked by tempol. Increased oxidative stress using peroxynitrite significantly increased TRPC6 transcripts to 4.29+/-1.26 (p<0.05) and TRPC6 protein expression to 1.28+/-0.05 (p<0.05) without altering SDC-4 transcripts or protein expression. In human podocytes transfected with scrambled siRNA, high d-glucose increased ROS after 90min to 3.55+/-0.08 arbitrary units while 5.6mmol/L d-glucose increased ROS to 2.49+/-0.09 (p<0.001) only. The increase in ROS was inhibited by tempol and by SDC-4 knockdown. High glucose modifies TRPC6 channels and ROS production via SDC-4 in human podocytes