212 research outputs found

    Minimizing energy demand and environmental impact for sustainable NH3 and H2O2 production—A perspective on contributions from thermal, electro-, and photo-catalysis

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    There is an urgent need to provide adequate and sustainable supplies of water and food to satisfy the demand of an increasing population. Catalysis plays important roles in meeting these needs by facilitating the synthesis of hydrogen peroxide that is used in water decontamination and chemicals production, and ammonia that is used as fertilizer. However, these chemicals are currently produced with processes that are either very energy-intensive or environmentally unfriendly. This article offers the perspectives of the challenges and opportunities in the production of these chemicals, focusing on the roles of catalysis in more sustainable, alternative production methods that minimize energy consumption and environmental impact. While not intended to be a comprehensive review, the article provides a critical review of selected literature relevant to its objectives, discusses areas needed for further research, and potential new directions inspired by new developments in related fields. For each chemical, production by thermal, electro-, and photo-excited processes are discussed. Problems that are common to these approaches and their differences are identified and possible solutions suggested

    Self-energy of Lambda in finite nuclei

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    The self--energy of the strange baryon Λ\Lambda in 17^{17}O is calculated using a microscopic many--body approach which accounts for correlations beyond the mean--field or Hartree--Fock approximation. The non-locality and energy-dependence of the Λ\Lambda self--energy is discussed and the effects on the bound and scattering states are investigated. For the nucleon--hyperon interaction, we use the potential models of the J\"{u}lich and Nijmegen groups.Comment: 17 pages, Revtex Latex style, 7 figs include

    Covariant Formulation of the Transition Radiation Energy Spectrum of an Electron Beam at a Normal Angle of Incidence onto a Round Metallic Screen

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    In the transition radiation emission from a N electron bunch hitting at a normal angle of incidence a metallic screen, the transverse and the longitudinal spatial coordinates of the electron bunch play different roles in determining the N single electron radiation field amplitudes and their relative phases in relation to the different physical constraints which an electromagnetic radiative mechanism by a charged beam must meet: i.e., temporal causality and covariance. The distribution of the N electron longitudinal coordinates determines indeed the sequence of the N electron collisions onto the metallic screen and, on the basis of the temporal causality principle, it also determines the distribution function of the relative emission phases of the N single electron field amplitudes from the metallic surface. The distribution of the transverse coordinates of the N electrons contributes as well to determine the relative phase distribution of the N electron field amplitudes at the observation point - located on the longitudinal axis of the reference frame - providing a further phase information that accounts for the transverse displacement of the N electrons with respect to the beam axis. The distribution of the transverse coordinates of the N electrons is a relativistic invariant under a Lorentz transformation with respect to the direction of motion of the beam and, consequently, it is expected to leave a covariant mark on the N single electron amplitudes composing the radiation field. The covariant imprinting of the N electron transverse density on the radiation field affects both the temporal coherent and incoherent parts of the transition radiation energy spectrum. Such a dependence of the N single electron radiation field amplitudes on the electron density in the transverse plane manifests itself as....(abstract partially missed because of lack of space

    Selection of internal reference genes for SYBR green qRT-PCR studies of rhesus monkey (Macaca mulatta) tissues

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    <p>Abstract</p> <p>Background</p> <p>The rhesus monkey (<it>Macaca mulatta</it>) is a valuable and widely used model animal for biomedical research. However, quantitative analyses of rhesus gene expression profiles under diverse experimental conditions are limited by a shortage of suitable internal controls for the normalization of mRNA levels. In this study, we used a systematic approach for the selection of potential reference genes in the rhesus monkey and compared their suitability to that of the corresponding genes in humans.</p> <p>Results</p> <p>Eight housekeeping genes (HKGs) (<it>GAPDH, SDHA, ACTB, RPL13A, RPL32, UBA52, PGK1Y</it>, and <it>YWHAZ</it>) from rhesus monkeys and humans were selected to test for normalization of expression levels in six different tissue types (brain, colon, kidney, liver, lung, and stomach). Their stability and suitability as reference genes were validated by <it>geNorm</it>, <it>NormFinder </it>and <it>BestKeeper </it>programs. Intriguingly, <it>RPL13A </it>and <it>RPL32 </it>were selected as ideal reference genes only in rhesus monkeys.</p> <p>Conclusion</p> <p>The results clearly indicated the necessity of using different reference genes for normalization of expression levels between rhesus monkeys and humans in various tissues.</p

    Phospholipase C??1 links inflammation and tumorigenesis in colitis-associated cancer

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    Colorectal cancer (CRC) is the third diagnosed cancer and the second leading cause of cancer-related deaths in the United States. Colorectal cancer is linked to inflammation and phospholipase C??1 (PLC??1) is associated with tumorigenesis and the development of colorectal cancer; however, evidence of mechanisms connecting them remains unclear. The tight junctions (TJ), as intercellular junctional complexes, have an important role for integrity of the epithelial barrier to regulate the cellular permeability. Here we found that PLC??1 regulated colitis and tumorigenesis in intestinal epithelial cells (IEC). To induce the colitis-associated cancer (CAC), we used the AOM/DSS model. Mice were sacrificed at 100 days (DSS three cycles) and 120 days (DSS one cycle). In a CAC model, we showed that the deletion of PLC??1 in IEC decreased the incidence of tumors by enhancing apoptosis and inhibiting proliferation during tumor development. Accordingly, the deletion of PLC??1 in IEC reduced colitisinduced epithelial inflammation via inhibition of pro-inflammatory cytokines and mediators. The PLC??1 pathway in IEC accelerated colitis-induced epithelial damage via regulation of TJ proteins. Conclusions: Our findings suggest that PLC??1 is a critical regulator of colitis and colorectal cancer and could further help in the development of therapy for colitis-associated cancer

    Genome-wide analysis of DNA methylation patterns in horse

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    Background: DNA methylation is an epigenetic regulatory mechanism that plays an essential role in mediating biological processes and determining phenotypic plasticity in organisms. Although the horse reference genome and whole transcriptome data are publically available the global DNA methylation data are yet to be known. Results: We report the first genome-wide DNA methylation characteristics data from skeletal muscle, heart, lung, and cerebrum tissues of thoroughbred (TH) and Jeju (JH) horses, an indigenous Korea breed, respectively by methyl-DNA immunoprecipitation sequencing. The analysis of the DNA methylation patterns indicated that the average methylation density was the lowest in the promoter region, while the density in the coding DNA sequence region was the highest. Among repeat elements, a relatively high density of methylation was observed in long interspersed nuclear elements compared to short interspersed nuclear elements or long terminal repeat elements. We also successfully identified differential methylated regions through a comparative analysis of corresponding tissues from TH and JH, indicating that the gene body regions showed a high methylation density. Conclusions: We provide report the first DNA methylation landscape and differentially methylated genomic regions (DMRs) of thoroughbred and Jeju horses, providing comprehensive DMRs maps of the DNA methylome. These data are invaluable resource to better understanding of epigenetics in the horse providing information for the further biological function analyses.open1

    Common Variants in a Novel Gene, FONG on Chromosome 2q33.1 Confer Risk of Osteoporosis in Japanese

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    Osteoporosis is a common disease characterized by low bone mass, decreased bone quality and increased predisposition to fracture. Genetic factors have been implicated in its etiology; however, the specific genes related to susceptibility to osteoporosis are not entirely known. To detect susceptibility genes for osteoporosis, we conducted a genome-wide association study in Japanese using ∼270,000 SNPs in 1,747 subjects (190 cases and 1,557 controls) followed by multiple levels of replication of the association using a total of ∼5,000 subjects (2,092 cases and 3,114 controls). Through these staged association studies followed by resequencing and linkage disequilibrium mapping, we identified a single nucleotide polymorphism (SNP), rs7605378 associated with osteoporosis. (combined P = 1.51×10−8, odds ratio = 1.25). This SNP is in a previously unknown gene on chromosome 2q33.1, FONG. FONG is predicted to encode a 147 amino-acid protein with a formiminotransferase domain in its N-terminal (FTCD_N domain) and is ubiquitously expressed in various tissues including bone. Our findings would give a new insight into osteoporosis etiology and pathogenesis

    Whole transcriptome analyses of six thoroughbred horses before and after exercise using RNA-Seq

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    Background: Thoroughbred horses are the most expensive domestic animals, and their running ability and knowledge about their muscle-related diseases are important in animal genetics. While the horse reference genome is available, there has been no large-scale functional annotation of the genome using expressed genes derived from transcriptomes. Results: We present a large-scale analysis of whole transcriptome data. We sequenced the whole mRNA from the blood and muscle tissues of six thoroughbred horses before and after exercise. By comparing current genome annotations, we identified 32,361 unigene clusters spanning 51.83 Mb that contained 11,933 (36.87%) annotated genes. More than 60% (20,428) of the unigene clusters did not match any current equine gene model. We also identified 189,973 single nucleotide variations (SNVs) from the sequences aligned against the horse reference genome. Most SNVs (171,558 SNVs; 90.31%) were novel when compared with over 1.1 million equine SNPs from two SNP databases. Using differential expression analysis, we further identified a number of exercise-regulated genes: 62 up-regulated and 80 down-regulated genes in the blood, and 878 up-regulated and 285 down-regulated genes in the muscle. Six of 28 previously-known exercise-related genes were over-expressed in the muscle after exercise. Among the differentially expressed genes, there were 91 transcription factor-encoding genes, which included 56 functionally unknown transcription factor candidates that are probably associated with an early regulatory exercise mechanism. In addition, we found interesting RNA expression patterns where different alternative splicing forms of the same gene showed reversed expressions before and after exercising. Conclusion: The first sequencing-based horse transcriptome data, extensive analyses results, deferentially expressed genes before and after exercise, and candidate genes that are related to the exercise are provided in this study.close151

    Genome-Wide Analysis of DNA Methylation before- and after Exercise in the Thoroughbred Horse with MeDIP-Seq

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    Athletic performance is an important criteria used for the selection of superior horses. However, little is known about exercise-related epigenetic processes in the horse. DNA methylation is a key mechanism for regulating gene expression in response to environmental changes. We carried out comparative genomic analysis of genome-wide DNA methylation profiles in the blood samples of two different thoroughbred horses before and after exercise by methylated-DNA immunoprecipitation sequencing (MeDIP-Seq). Differentially methylated regions (DMRs) in the pre- and post-exercise blood samples of superior and inferior horses were identified. Exercise altered the methylation patterns. After 30 min of exercise, 596 genes were hypomethylated and 715 genes were hypermethylated in the superior horse, whereas in the inferior horse, 868 genes were hypomethylated and 794 genes were hypermethylated. These genes were analyzed based on gene ontology (GO) annotations and the exercise-related pathway patterns in the two horses were compared. After exercise, gene regions related to cell division and adhesion were hypermethylated in the superior horse, whereas regions related to cell signaling and transport were hypermethylated in the inferior horse. Analysis of the distribution of methylated CpG islands confirmed the hypomethylation in the gene-body methylation regions after exercise. The methylation patterns of transposable elements also changed after exercise. Long interspersed nuclear elements (LINEs) showed abundance of DMRs. Collectively, our results serve as a basis to study exercise-based reprogramming of epigenetic traitsclose

    A global experiment on motivating social distancing during the COVID-19 pandemic

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    Finding communication strategies that effectively motivate social distancing continues to be a global public health priority during the COVID-19 pandemic. This cross-country, preregistered experiment (n = 25,718 from 89 countries) tested hypotheses concerning generalizable positive and negative outcomes of social distancing messages that promoted personal agency and reflective choices (i.e., an autonomy-supportive message) or were restrictive and shaming (i.e., a controlling message) compared with no message at all. Results partially supported experimental hypotheses in that the controlling message increased controlled motivation (a poorly internalized form of motivation relying on shame, guilt, and fear of social consequences) relative to no message. On the other hand, the autonomy-supportive message lowered feelings of defiance compared with the controlling message, but the controlling message did not differ from receiving no message at all. Unexpectedly, messages did not influence autonomous motivation (a highly internalized form of motivation relying on one’s core values) or behavioral intentions. Results supported hypothesized associations between people’s existing autonomous and controlled motivations and self-reported behavioral intentions to engage in social distancing. Controlled motivation was associated with more defiance and less long-term behavioral intention to engage in social distancing, whereas autonomous motivation was associated with less defiance and more short- and long-term intentions to social distance. Overall, this work highlights the potential harm of using shaming and pressuring language in public health communication, with implications for the current and future global health challenges
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