65 research outputs found

    Porosity tunable graphitic carbons for energy applications

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    School of Molecular Sciences(Chemical Engineering)With growing demand on energy sources, diminishing natural resources and increasing environment issues, the development of safe, no-pollution, low-cost and renewable energy systems where combustion no longer dominates has become a grand challenge nowadays. Among the various energy storage systems, supercapacitor and Zn-air batteries are considered as the most realizable and effective candidates due to their high efficiency, safety, durability, and low cost. Supercapacitor electrode requires the large surface area, good chemical stability, and high electrical conductivity because it stores charges by electrostatic adsorption/desorption of the electrolyte ions onto electrodes. Besides, in the case of the Zn-air battery, the development of highly efficient oxygen catalyst without precious metal including Pt, Ir, and Ru which facilitates the sluggish oxygen related reaction is required for real application. This thesis covers the development of three-dimensional porous graphitic carbon structures and their applications to supercapacitor electrodes and oxygen electrocatalyst for Zn-air battery. The excellent property of porous carbon architectures for energy applications are mostly due to the large specific surface area with desirable porosity and the large amount of electrochemical active site density. This work suggests the promising way to fabricate highly efficient and durable carbon nanomaterials for energy-related applications.ope

    Glomangiomyoma of the Trachea

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    A glomus tumor is an uncommon soft tissue tumor that is most commonly found in the subungual area and a glomus originating in the trachea is extremely rare. Histologically and ultrastructurally, these tumors have been divided into three subtypes: classic glomus tumors, glomangiomas, and glomangiomyomas. Glomangiomyomas account for less than 10% of all glomus tumors and are the least common type. We report a case of a 54-year-old man with glomangiomyoma of the trachea who presented with stridor. We treated the tumor by segmental resection and primary repair via a transcervical approach

    Differential transcriptome profile underlying risky choice in a rat gambling task

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    Background and aims: Proper measurement of expected risk is important for making rational decisions, and maladaptive decision making may underlie various psychiatric disorders. However, differentially expressed genetic profiling involved in this process is still largely unknown. A rodent version of the gambling task (rGT) has been developed to measure decision-making by adopting the same principle of Iowa Gambling Task in humans. In the present study, we examined using next-generation sequencing (NGS) technique whether there are differences in gene expression profiles in the medial prefrontal cortex (mPFC) and the nucleus accumbens (NAc) when rats make different choices toward risk in rGT. Methods: Rats were trained in a touch screen chamber to learn the relationships between 4 different light signals on the window of the screen and accompanied reward outcomes or punishments set up with different magnitudes and probabilities. Once they showed a stabilized pattern of preference upon free choice, rats were classified into risk-averse or risk-seeking groups. After performing the rGT, rats were decapitated, the mPFC and the NAc was dissected out, and NGS was performed with the total RNA extracted. Results: We found that 477 and 36 genes were differentially expressed (approximately 75 and 83% out of them were downregulated) in the mPFC and the NAc, respectively, in risk-seeking compared to risk-averse rats. Among those, we suggested a few top ranked genes that may contribute to promoting risky choices. Discussion and conclusions: Our findings provide insights into transcriptional components underlying risky choices in rats

    NiFeOx decorated Ge-hematite/perovskite for an efficient water splitting system

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    To boost the photoelectrochemical water oxidation performance of hematite photoanodes, high temperature annealing has been widely applied to enhance crystallinity, to improve the interface between the hematite-substrate interface, and to introduce tin-dopants from the substrate. However, when using additional dopants, the interaction between the unintentional tin and intentional dopant is poorly understood. Here, using germanium, we investigate how tin diffusion affects overall photoelectrochemical performance in germanium:tin co-doped systems. After revealing that germanium is a better dopant than tin, we develop a facile germanium-doping method which suppresses tin diffusion from the fluorine doped tin oxide substrate, significantly improving hematite performance. The NiFeOx@Ge-PH photoanode shows a photocurrent density of 4.6mAcm(-2) at 1.23 V-RHE with a low turn-on voltage. After combining with a perovskite solar cell, our tandem system achieves 4.8% solar-to-hydrogen conversion efficiency (3.9mAcm(-2) in NiFeOx@Ge-PH/perovskite solar water splitting system). Our work provides important insights on a promising diagnostic tool for future co-doping system design. Germanium (Ge) has potential as a dopant suitable for the hematite-based photoelectrochemical water splitting system. Here, the authors report the fabrication of Ge doped porous hematite and demonstrate an efficient tandem system of Ge doped porous hematite and the perovskite solar cell

    Cetaceans evolution:insights from the genome sequences of common minke whales

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    Background: Whales have captivated the human imagination for millennia. These incredible cetaceans are the only mammals that have adapted to life in the open oceans and have been a source of human food, fuel and tools around the globe. The transition from land to water has led to various aquatic specializations related to hairless skin and ability to regulate their body temperature in cold water. Results: We present four common minke whale (Balaenoptera acutorostrata) genomes with depth of ×13 ~ ×17 coverage and perform resequencing technology without a reference sequence. Our results indicated the time to the most recent common ancestors of common minke whales to be about 2.3574 (95% HPD, 1.1521 - 3.9212) million years ago. Further, we found that genes associated with epilation and tooth-development showed signatures of positive selection, supporting the morphological uniqueness of whales. Conclusions: This whole-genome sequencing offers a chance to better understand the evolutionary journey of one of the largest mammals on earth

    Genetic Drivers of Heterogeneity in Type 2 Diabetes Pathophysiology

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    Type 2 diabetes (T2D) is a heterogeneous disease that develops through diverse pathophysiological processes1,2 and molecular mechanisms that are often specific to cell type3,4. Here, to characterize the genetic contribution to these processes across ancestry groups, we aggregate genome-wide association study data from 2,535,601 individuals (39.7% not of European ancestry), including 428,452 cases of T2D. We identify 1,289 independent association signals at genome-wide significance (P \u3c 5 × 10-8) that map to 611 loci, of which 145 loci are, to our knowledge, previously unreported. We define eight non-overlapping clusters of T2D signals that are characterized by distinct profiles of cardiometabolic trait associations. These clusters are differentially enriched for cell-type-specific regions of open chromatin, including pancreatic islets, adipocytes, endothelial cells and enteroendocrine cells. We build cluster-specific partitioned polygenic scores5 in a further 279,552 individuals of diverse ancestry, including 30,288 cases of T2D, and test their association with T2D-related vascular outcomes. Cluster-specific partitioned polygenic scores are associated with coronary artery disease, peripheral artery disease and end-stage diabetic nephropathy across ancestry groups, highlighting the importance of obesity-related processes in the development of vascular outcomes. Our findings show the value of integrating multi-ancestry genome-wide association study data with single-cell epigenomics to disentangle the aetiological heterogeneity that drives the development and progression of T2D. This might offer a route to optimize global access to genetically informed diabetes care

    Genetic drivers of heterogeneity in type 2 diabetes pathophysiology

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    Type 2 diabetes (T2D) is a heterogeneous disease that develops through diverse pathophysiological processes1,2 and molecular mechanisms that are often specific to cell type3,4. Here, to characterize the genetic contribution to these processes across ancestry groups, we aggregate genome-wide association study data from 2,535,601 individuals (39.7% not of European ancestry), including 428,452 cases of T2D. We identify 1,289 independent association signals at genome-wide significance (P &lt; 5 × 10-8) that map to 611 loci, of which 145 loci are, to our knowledge, previously unreported. We define eight non-overlapping clusters of T2D signals that are characterized by distinct profiles of cardiometabolic trait associations. These clusters are differentially enriched for cell-type-specific regions of open chromatin, including pancreatic islets, adipocytes, endothelial cells and enteroendocrine cells. We build cluster-specific partitioned polygenic scores5 in a further 279,552 individuals of diverse ancestry, including 30,288 cases of T2D, and test their association with T2D-related vascular outcomes. Cluster-specific partitioned polygenic scores are associated with coronary artery disease, peripheral artery disease and end-stage diabetic nephropathy across ancestry groups, highlighting the importance of obesity-related processes in the development of vascular outcomes. Our findings show the value of integrating multi-ancestry genome-wide association study data with single-cell epigenomics to disentangle the aetiological heterogeneity that drives the development and progression of T2D. This might offer a route to optimize global access to genetically informed diabetes care.</p
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