1,335 research outputs found

    Anisotropic elastic constants calculation of stainless steel cladded layers of pressure vessel steel plate

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    Cladding stainless steel layer on the inner surface of ferrite pressure vessel is a common method to improve the corrosion resistance and save the economic cost. However, the movement of heat source and temperature gradient in the process of cladded welding will lead to the anisotropy of cladded layer material. When measuring the residual stress of pressure vessel steel plate with stainless steel cladded layers (SSCL) by contour method, it is necessary to know the elastic mechanical properties of stainless steel cladded layers accurately. The assumption of transversely isotropy (TI) was employed, and the relationship between the material compliance matrix and the elastic modulus of transversely isotropic material was utilized. Based on the elastic modulus of each cladded layer and the whole steel plate from the longitudinal direction (0°) until the transverse direction (90°) measured by the experiment, the independent constants S11, S13, S33 and S44 in the compliance matrix of each cladded layer and the whole steel plate were obtained by regression analysis method. Furthermore, by using the relationship between the independent constants of the stiffness matrix of the transversely isotropic material and the single crystal material, the independent constant S12 in the compliance matrix of each stainless steel cladded layer and the whole steel plate were obtained. And then the independent constants of the stiffness matrix of each cladded layer and the whole steel plate were acquired. Hence, a method for calculating the anisotropic elastic constants of the stainless steel cladded layer and the whole steel plate was proposed. The results will provide material data support for measuring residual stress of pressure vessel steel plate with stainless steel cladded layers by contour method

    The prevalence of depressive symptoms among older patients with hypertension in rural China

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    Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/139900/1/gps4628.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/139900/2/gps4628_am.pd

    Protocol of an ongoing randomized controlled trial of care management for comorbid depression and hypertension: the Chinese Older Adult Collaborations in Health (COACH) study

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    Abstract Background Depression and hypertension are common, costly, and destructive conditions among the rapidly aging population of China. The two disorders commonly coexist and are poorly recognized and inadequately treated, especially in rural areas. Methods The Chinese Older Adult Collaborations in Health (COACH) Study is a cluster randomized controlled trial (RCT) designed to test the hypotheses that the COACH intervention, designed to manage comorbid depression and hypertension in older adult, rural Chinese primary care patients, will result in better treatment adherence and greater improvement in depressive symptoms and blood pressure control, and better quality of life, than enhanced Care-as-Usual (eCAU). Based on chronic disease management and collaborative care principles, the COACH model integrates the care provided by the older person’s primary care provider (PCP) with that delivered by an Aging Worker (AW) from the village’s Aging Association, supervised by a psychiatrist consultant. One hundred sixty villages, each of which is served by one PCP, will be randomly selected from two counties in Zhejiang Province and assigned to deliver eCAU or the COACH intervention. Approximately 2400 older adult residents from the selected villages who have both clinically significant depressive symptoms and a diagnosis of hypertension will be recruited into the study, randomized by the villages in which they live and receive primary care. After giving informed consent, they will undergo a baseline research evaluation; receive treatment for 12 months with the approach to which their village was assigned; and be re-evaluated at 3, 6, 9, and 12 months after entry. Depression and HTN control are the primary outcomes. Treatment received, health care utilization, and cost data will be obtained from the subjects’ electronic medical records (EMR) and used to assess adherence to care recommendations and, in a preliminary manner, to establish cost and cost effectiveness of the intervention. Discussion The COACH intervention is designed to serve as a model for primary care-based management of common mental disorders that occur in tandem with common chronic conditions of later life. It leverages existing resources in rural settings, integrates social interventions with the medical model, and is consistent with the cultural context of rural life. Trial registration ClinicalTrials.gov ID: NCT01938963 ; First posted: September 10, 2013.https://deepblue.lib.umich.edu/bitstream/2027.42/143862/1/12877_2018_Article_808.pd

    Pain during and after coronavirus disease 2019:Chinese perspectives

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    Ultralong nitrogen/sulfur Co‐doped carbon nano‐hollow‐sphere chains with encapsulated cobalt nanoparticles for highly efficient oxygen electrocatalysis

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    The development of simple and effective strategies to prepare electrocatalysts, which possess unique and stable structures comprised of metal/nonmetallic atoms for oxygen reduction reaction (ORR) and oxygen evolution reaction (OER), is currently an urgent issue. Herein, an efficient bifunctional electrocatalyst featured by ultralong N, S-doped carbon nano-hollow-sphere chains about 1300 nm with encapsulated Co nanoparticles (Co-CNHSCs) is developed. The multifunctional catalytic properties of Co together with the heteroatom-induced charge redistribution (i.e., modulating the electronic structure of the active site) result in superior catalytic activities toward OER and ORR in alkaline media. The optimized catalyst Co-CNHSC-3 displays an outstanding electrocatalytic ability for ORR and OER, a high specific capacity of 1023.6 mAh gZn−1, and excellent reversibility after 80 h at 10 mA cm−2 in a Zn-air battery system. This work presents a new strategy for the design and synthesis of efficient multifunctional carbon-based catalysts for energy storage and conversion devices

    Finite element modeling and fatigue life prediction of helicopter composite tail structure under multipoint coordinated loading spectrum

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    This paper presents a numerical study on fatigue life prediction of helicopter composite tail structure under multipoint coordinated loading spectrum. The FE model of a full-scale helicopter composite tail structure was established and then validated with the experimental results of strain and displacement distributions. Good agreement has been achieved between simulation and experiments under two multipoint coordinated static loading conditions representing left yawing and two-point horizontal landing. A progressive damage analysis was performed on the tail structure model under multipoint coordinated spectrum loading. The predicted fatigue life of the helicopter tail structure is 64 repeated applications of the load spectrum. No element failure was predicted on the tail structure after 48 repeated applications of the load spectrum. The impact damage introduced on the left-side wall thereafter propagated after another 6 repeated applications of the load spectrum, which agrees well with experimental observations. The progressive damage analysis has been shown to be a practical engineering tool for life prediction of helicopter composite structure

    Complete mitochondrial genomes of Taenia multiceps, T. hydatigena and T. pisiformis: additional molecular markers for a tapeworm genus of human and animal health significance

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    <p>Abstract</p> <p>Background</p> <p>Mitochondrial genomes provide a rich source of molecular variation of proven and widespread utility in molecular ecology, population genetics and evolutionary biology. The tapeworm genus <it>Taenia </it>includes a diversity of tapeworm parasites of significant human and veterinary importance. Here we add complete sequences of the mt genomes of <it>T. multiceps</it>, <it>T. hydatigena </it>and <it>T. pisiformis</it>, to a data set of 4 published mtDNAs in the same genus. Seven complete mt genomes of <it>Taenia </it>species are used to compare and contrast variation within and between genomes in the genus, to estimate a phylogeny for the genus, and to develop novel molecular markers as part of an extended mitochondrial toolkit.</p> <p>Results</p> <p>The complete circular mtDNAs of <it>T. multiceps</it>, <it>T. hydatigena </it>and <it>T. pisiformis </it>were 13,693, 13,492 and 13,387 bp in size respectively, comprising the usual complement of flatworm genes. Start and stop codons of protein coding genes included those found commonly amongst other platyhelminth mt genomes, but the much rarer initiation codon GTT was inferred for the gene <it>atp</it>6 in <it>T. pisiformis</it>. Phylogenetic analysis of mtDNAs offered novel estimates of the interrelationships of <it>Taenia</it>. Sliding window analyses showed <it>nad</it>6, <it>nad</it>5, <it>atp</it>6, <it>nad</it>3 and <it>nad</it>2 are amongst the most variable of genes per unit length, with the highest peaks in nucleotide diversity found in <it>nad</it>5. New primer pairs capable of amplifying fragments of variable DNA in <it>nad</it>1, <it>rrn</it>S and <it>nad</it>5 genes were designed <it>in silico </it>and tested as possible alternatives to existing mitochondrial markers for <it>Taenia</it>.</p> <p>Conclusions</p> <p>With the availability of complete mtDNAs of 7 <it>Taenia </it>species, we have shown that analysis of amino acids provides a robust estimate of phylogeny for the genus that differs markedly from morphological estimates or those using partial genes; with implications for understanding the evolutionary radiation of important <it>Taenia</it>. Full alignment of the nucleotides of <it>Taenia </it>mtDNAs and sliding window analysis suggests numerous alternative gene regions are likely to capture greater nucleotide variation than those currently pursued as molecular markers. New PCR primers developed from a comparative mitogenomic analysis of <it>Taenia </it>species, extend the use of mitochondrial markers for molecular ecology, population genetics and diagnostics.</p

    The cross-reactivity of the enterovirus 71 to human brain tissue and identification of the cross-reactivity related fragments

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    <p>Abstract</p> <p>Background</p> <p>EV71 occasionally cause a series of severe neurological symptoms, including aseptic meningitis, encephalitis, and poliomyelitis-like paralysis. However, the neurological destruction mechanism was remained to be clarified. This study described the cross reaction between EV71 induced IgG and human brain tissue.</p> <p>Results</p> <p>Cross reaction of the IgG from 30 EV71 infected patients' sera to human tissues of cerebra was observed, which suggested that some EV71 antigens could induce IgG cross-reactivity to human cerebra. To identify the regions of EV71 virus that containing above antigens, the polypeptide of virus was divided into 19 peptides by expression in prokaryotes cell. Mouse anti-sera of these peptides was prepared and applied in immunohistochemical staining with human adult and fetus brain tissue, respectively. The result indicated the 19 peptides can be classified into three groups: strong cross-reactivity, weak cross-reactivity and no cross-reactivity with human brain tissue according the cross reaction activity. Then, the increased Blood Brain Barrier (BBB) permeability and permits IgG entry in neonatal mice after EV71 infection was determined.</p> <p>Conclusion</p> <p>EV71 induced IgG could enter BBB and cross-reacted with brain tissue in EV71 infected neonatal mice, and then the peptides of EV71 that could induce cross-reactivity with brain tissue were identified, which should be avoided in future vaccine designing.</p
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