186 research outputs found

    Solvation shell dynamics of supercritical water–cyclohexane mixtures in relation to the translational and rotational dynamics as studied by molecular dynamics simulation

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    The translational dynamics of water and cyclohexane in supercritical binary mixtures were investigated using molecular dynamics simulations. The effects of the local composition were examined through a decomposition scheme of the conditional time-correlation functions based on the solvation numbers for water and cyclohexane. The self-diffusion of water was found to be largely controlled by the continuous and collective attractive interactions with surrounding water molecules, while interactions with cyclohexane have minimal impact on water diffusion. On the other hand, the self-diffusion of cyclohexane is dominantly determined by uncorrelated collisional interactions with neighboring cyclohexane molecules. The results demonstrate the dynamic aspect of microscopic inhomogeneity and highlight the significance of interactions between molecules of the same species. An examination of the dependence of self-diffusion on the lifetime of the solvation shell indicated that the self-diffusion of water is confined within the solvation shell. This is attributed to the hydrogen bond interactions with neighboring water molecules, which create an energy barrier to the water molecules diffusing out of the hydration cage. In contrast, diffusing cyclohexane molecules migrate beyond the solvation shell, particularly at large water contents

    Polysemy Detection in Distributed Representation of Word Sense

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    In this paper, we propose a statistical test to determine whether a given word is used as a polysemic word or not. The statistic of the word in this test roughly corresponds to the fluctuation in the senses of the neighboring words a nd the word itself. Even though the sense of a word corresponds to a single vector, we discuss how polysemy of the words affects the position of vectors. Finally, we also explain the method to detect this effect.Comment: The 9th International Conference on Knowledge and Smart Technology (KST-2017

    Implementation of High-Speed Pseudo-Random-Number Generator with Chaotic and Random Neural Networks

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    Chaotic and random time series generated from improved chaotic and random neural network (CRNN) afford statistically appropriate pseudo-random number series for information security. Randomness of outputs of CRNN is empirically validated in detail, and control methods of an appropriate ratio of chaotic character and randomness in the time series for PRNG is reported. The rate of random number generation has reached 2.8530×10^12 b/s. In future, the generator may play an important role on implementing applications for protecting personal information on the Internet

    14N NMR Evidence for Initial Production of NH3 Accompanied by Alcohol from the Hydrolysis of Ethylamine and Butylamine in Supercritical Water

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    A 14N and 1H NMR spectroscopic study 1 was carried out to shed light on the microscopic aspects of the reaction of model alkylamines at a supercritical temperature of 400 °C. It is disclosed that NH3 and ROH (R = CH3CH2 and CH3 (CH2)3) are initially produced from the hydrolysis of ethylamine and butylamine, respectively. When the water density is doubled from 0.2 g cm−3, the pseudo-first-order reaction rate is markedly enhanced beyond the linear response. It suggests that the transition state of C-N bond cleavage is in a dipolar (ionic) state that can be more stabilized due to the many-body solvation by highly polar water molecules at a higher density

    Pulmonary Fibrosis in Response to Environmental Cues and Molecular Targets Involved in Its Pathogenesis

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    Chronic lung injury resulting from a variety of different causes is frequently associated with the develop ment of pulmonary fibrosis in humans. Although the etiology of pulmonary fibrosis is generally unknown, several sources of evidence support the hypothesis that a number of environmental and occupational agents play an etiologic role in the pathogenesis of this disease. The agents discussed in this review include beryllium, nylon flock, textile printing aerosols, polyvinyl chloride and didecyldimethylammonium chloride. The authors also describe a variety of animal models, including genetically modified mice, in order to investigate the molecular mechanism of pulmonary fibrosis, focusing on chemokine receptors, regulatory T cells and transforming growth factor-β and bone morphogenetic protein signaling. Overall, we propose the concept of toxicological pulmonary fibrosis as a lung disease induced in response to environmental cues

    MIWI N-terminal arginines orchestrate generation of functional pachytene piRNAs and spermiogenesis

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    N-terminal arginine (NTR) methylation is a conserved feature of PIWI proteins, which are central components of the PIWI-interacting RNA (piRNA) pathway. The significance and precise function of PIWI NTR methylation in mammals remains unknown. In mice, PIWI NTRs bind Tudor domain containing proteins (TDRDs) that have essential roles in piRNA biogenesis and the formation of the chromatoid body. Using mouse MIWI (PIWIL1) as paradigm, we demonstrate that the NTRs are essential for spermatogenesis through the regulation of transposons and gene expression. The loss of TDRD5 and TDRKH interaction with MIWI results in attenuation of piRNA amplification. We find that piRNA amplification is necessary for transposon control and for sustaining piRNA levels including select, nonconserved, pachytene piRNAs that target specific mRNAs required for spermatogenesis. Our findings support the notion that the vast majority of pachytene piRNAs are dispensable, acting as self-serving genetic elements that rely for propagation on MIWI piRNA amplification. MIWI-NTRs also mediate interactions with TDRD6 that are necessary for chromatoid body compaction. Furthermore, MIWI-NTRs promote stabilization of spermiogenic transcripts that drive nuclear compaction, which is essential for sperm formation. In summary, the NTRs underpin the diversification of MIWI protein function

    A Nuclear Magnetic Resonance Study on Rubrene-cobalt Nano-composites

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    We implemented a nuclear magnetic resonance (NMR) study on rubrene(C42H28)-Co nano-composites that exhibit an enhanced magnetoresistance (MR) ratio of 80%. The 59Co NMR spin echo experiment enabled clarification of the hyperfine field of Co at the interface between the ferromagnet and the molecules, which has not been investigated for molecular spintronics. An enhanced hyperfine field of the Co was observed in the rubrene-Co nano-composites, which may be related to the enhancement of the MR ratio. This study demonstrates the importance of microscopic investigation of the interface between molecules and ferromagnets that governs spin-dependent transport in molecular spin devices.Comment: 12pages, 3 figures, 1 tabl

    Secretory Carcinoma of Salivary Gland with High-Grade Histology Arising in Hard Palate: A Case Report

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    Secretory carcinoma (SC) is a recently described salivary gland tumor reported in the fourth edition of World Health Organization classification of head and neck tumors. SC is characterized by strong S-100 protein, mammaglobin, and vimentin immunoexpression, and harbors a t(12;15)(p13;q25) translocation which leads to ETV6-NTRK3 fusion product. Histologically, SC displays a lobulated growth pattern and is often composed of microcystic, tubular, and solid structures with abundant eosinophilic homogenous or bubbly secretion. SC is generally recognized as low-grade malignancy with low-grade histopathologic features, and metastasis is relatively uncommon. In this case, we described a SC of hard palate that underwent high grade transformation and metastasis to the cervical lymph node in a 54-year-old patient. In addition, this case showed different histological findings between primary lesion and metastasis lesion. Therefore, the diagnosis was confirmed by the presence of ETV6 translocation. Here, we report a case that occurred SC with high-grade transformation in the palate, and a review of the relevant literature is also presented

    Colon cancer form a colonic graft

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    Neoplasm of a colonic graft after esophageal reconstruction is rare. We treated a colon cancer patient who developed malignancy in a colonic graft after esophagectomy and reconstruction through a retrosternal route. A male had undergone esophagectomy in his 50s due to a benign esophago-bronchial fistula. His dysphagia became exacerbated 20 years later, and further examinations showed a circumferential tumor on the esophago-colonic anastomosis. He underwent resection of the colonic graft adenocarcinoma with median sternotomy after neoadjuvant chemotherapy. Gastric tube reconstruction was performed through a retrosternal route. This report should be informative in terms of making decisions from an initial reconstruction to follow-up and choosing a therapeutic strategy for colonic graft cancer in the future
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