154 research outputs found

    A study on compressive anisotropy and nonassociated flow plasticity of the AZ31 Magnesium Alloy in hot rolling

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    Effect of anisotropy in compression is studied on hot rolling of AZ31 magnesium alloy with a three-dimensional constitutive model based on the quadratic Hill48 yield criterion and nonassociated flow rule (non-AFR). The constitutive model is characterized by compressive tests of AZ31 billets since plastic deformations of materials are mostly caused by compression during rolling processes. The characterized plasticity model is implemented into ABAQUS/Explicit as a user-defined material subroutine (VUMAT) based on semi-implicit backward Euler\u27s method. The subroutine is employed to simulate square-bar rolling processes. The simulation results are compared with rolled specimens and those predicted by the von Mises and the Hill48 yield function under AFR. Moreover, strip rolling is also simulated for AZ31 with the Hill48 yield function under non-AFR. The strip rolling simulation demonstrates that the lateral spread generated by the non-AFR model is in good agreement with experimental data. These comparisons between simulation and experiments validate that the proposed Hill48 yield function under non-AFR provides satisfactory description of plastic deformation behavior in hot rolling for AZ31 alloys in case that the anisotropic parameters in the Hill48 yield function and the non-associated flow rule are calibrated by the compressive experimental results

    Transcriptome of Small Regulatory RNAs in the Development of the Zoonotic Parasite Trichinella spiralis

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    BACKGROUND: Trichinella spiralis is a parasite with unique features. It is a multicellular organism but with an intracellular parasitization and development stage. T. spiralis is the helminthic pathogen that causes zoonotic trichinellosis and afflicts more than 10 million people worldwide, whereas the parasite's biology, especially the developmental regulation is largely unknown. In other organisms, small non-coding RNAs, such as microRNAs (miRNA) and small interfering RNAs (siRNA) execute post-transcriptional regulation by translational repression or mRNA degradation, and a large number of miRNAs have been identified in diverse species. In T. spiralis, the profile of small non-coding RNAs and their function remains poorly understood. METHODOLOGY AND PRINCIPAL FINDINGS: Here, the transcriptional profiles of miRNA and siRNA in three developmental stages of T. spiralis in the rat host were investigated, and compared by high-throughput cDNA sequencing technique ("RNA-seq"). 5,443,641 unique sequence tags were obtained. Of these, 21 represented conserved miRNAs related to 13 previously identified metazoan miRNA families and 213 were novel miRNAs so far unique to T. spiralis. Some of these miRNAs exhibited stage-specific expression. Expression of miRNAs was confirmed in three stages of the life cycle by qRT-PCR and northern blot analysis. In addition, endogenous siRNAs (endo-siRNAs) were found mainly derived from natural antisense transcripts (NAT) and transposable elements (TE) in the parasite. CONCLUSIONS AND SIGNIFICANCE: We provide evidence for the presence of miRNAs and endo-siRNAs in T. spiralis. The miRNAs accounted for the major proportion of the small regulatory RNA population of T. spiralis, while fewer endogenous siRNAs were found. The finding of stage-specific expression patterns of the miRNAs in different developmental stages of T. spiralis suggests that miRNAs may play important roles in parasite development. Our data provide a basis for further understanding of the molecular regulation and functional evolution of miRNAs in parasitic nematodes

    Allicin modulates the intestinal microbiota to attenuate blood glucose and systemic inflammation in type 2 diabetic rats

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    IntroductionAllicin is a wide spectrum prebiotic for human health, but whether it can attenuate blood in diabetes patients is rarely reported. In this study, we built a rat model and investigated the effect of allicin on diabetes mellitus type 2 (T2DM). We found that allicin could effectively reduce blood glucose levels, regulate intestinal microbiota, reduce lipid and body weight accumulation, and systemic inflammation in T2DM rats.MethodsThe rat model of type 2 diabetes was made by streptozotocin, and different doses of allicin were given orally by gavage. The intestinal contents of diabetes rats were sequenced and analyzed by 16S technology, and the clinical indicators of rats were detected for joint analysis.ResultsAllicin can improve the intestinal flora of type 2 diabetes rats, enrich beneficial metabolites, reduce blood glucose, improve blood lipids, reduce systemic inflammation, and improve type 2 diabetes.DiscussionIntestinal microbiome analysis showed that allicin gavage significantly regulated the structure and main components of the intestinal microbiota in T2DM rats. Allicin increased the abundance of probiotic microbes, such as Lactobacillus, Clostridium and Akkermansia, while it reduced pathogenic microbes, such as Enterobacter, Erysipelatoclostridium and Colidextribacter. Allicin gavage increased the abundance of intestinal short-chain fatty acids, such as acetic acid and propionic acid. Correlation analysis showed that the increased gut microbes by allicin gavage were significantly associated with health physiological parameters but negatively related to serum inflammatory factors such as interleukin-6 (IL-6), tumor necrosis factor alpha (TNF-a), and hypersensitive C-reactive protein (hs-CRP). In addition, our study also suggests that allicin may have prebiotic effects on chronic liver injury. This study shows that allicin can regulate various clinical symptoms of T2DM and is a potential therapeutic drug for T2DM

    Drought resistance index screening and evaluation of lettuce under water deficit conditions on the basis of morphological and physiological differences

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    IntroductionWater is one of the important factors affecting the yield of leafy vegetables. Lettuce, as a widely planted vegetable, requires frequent irrigation due to its shallow taproot and high leaf evaporation rate. Therefore, screening drought-resistant genotypes is of great significance for lettuce production.MethodsIn the present study, significant variations were observed among 13 morphological and physiological traits of 42 lettuce genotypes under normal irrigation and water-deficient conditions.ResultsFrequency analysis showed that soluble protein (SP) was evenly distributed across six intervals. Principal component analysis (PCA) was conducted to transform the 13 indexes into four independent comprehensive indicators with a cumulative contribution ratio of 94.83%. The stepwise regression analysis showed that root surface area (RSA), root volume (RV), belowground dry weight (BDW), soluble sugar (SS), SP, and leaf relative water content (RWC) could be used to evaluate and predict the drought resistance of lettuce genotypes. Furthermore, the drought resistance ranks of the genotypes were similar according to the drought resistance comprehensive evaluation value (D value), comprehensive drought resistance coefficient (CDC), and weight drought resistance coefficient (WDC). The cluster analysis enabled the division of the 42 genotypes into five drought resistance groups; among them, variety Yidali151 was divided into group I as a strongly drought-resistant variety, group II included 6 drought-resistant genotypes, group III included 16 moderately drought-resistant genotypes, group IV included 12 drought-sensitive genotypes, and group V included 7 highly drought-sensitive genotypes. Moreover, a representative lettuce variety was selected from each of the five groups to verify its water resistance ability under water deficit conditions. In the drought-resistant variety, it was observed that stomatal density, superoxide anion (O2.−wfi2) production rate, and malondialdehyde (MDA) content exhibited a low increase rate, while catalase (CAT), superoxide dismutase (SOD), and that peroxidase (POD) activity exhibited a higher increase than in the drought-sensitive variety.DiscussionIn summary, the identified genotypes are important because their drought-resistant traits can be used in future drought-resistant lettuce breeding programs and water-efficient cultivation

    A motivação e a cooperação desportiva no atletismo

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    A educação física para as crianças e jovens, consiste num período crítico do percurso educacional, dado que pode promover o seu futuro envolvimento desportivo e decisões acerca da sua participação em actividades físicas futuras. Deste modo, o estudo de modelos ou a identificação de determinantes psicológicas, assume-se como uma necessidade para o desenvolvimento de intervenções adequadas para o aumento dos níveis de actividade física. A orientação motivacional e o sentido de cooperação, são factores de primordial importância na coordenação e no sucesso de diversas actividades humanas, e de impacto bem visível no âmbito do desporto. Assim, o presente trabalho destina-se à verificação das possibilidades de correlação entre orientação motivacional e sentido de cooperação em participantes de uma mesma modalidade desportiva, neste caso o atletismo, para o que se utilizou o “Task and Ego Orientation in Sport Questionnaire” (TEOSQ), na versão portuguesa desenvolvido por Duda e colaboradores (1989, 1992, citado por Cruz, 1996), de Fonseca e Brito, (2006) e o Cuestionario de Cooperación Deportiva (CCD), igualmente na versão portuguesa, de Almeida, Garcia-Mas, Lameiras, Olmedílla, Ortega, Martins, (2006). A amostra foi constituída por 52 atletas, onde 51,9% dos sujeitos são do sexo masculino e 48,1% são do sexo feminino, de diversas especialidades.ABSTRACT: Physical education for children and young people is a critical period of the educational process, as this selling may promote individual`s futures involvement in physical activity and sports, and may influence young persons decisions about future sport and activity participation. Therefore, the study of models and identification of psychology variables, underscores the need of developing interventions to increase physical activity. The motivational orientation and the direction of cooperation are factors of primordial importance in the coordination and the success of diverse activities human beings, and well visible impact in the scope of the sport. Thus, the present work destines it verification of the possibilities of correlation between the motivational orientation an direction of cooperation in participants of one same porting modality, in this in case that the track and field so that it was used “Task and Ego Orientation in Sport Questionnaire” (TEOSQ), in the Portuguese version developed by Duda and Collaborators (1989, 1992, cited for Cruz, 1996), and the Cuestionario de Cooperación Deportiva (CCD),equally in the Portuguese version of Almeida, Garcia-Mas, Lameiras, Olmedílla, Ortega, Martins, (2006). A sample of 52 athletes, of diverse modalities

    Study on the evaluation of the clinical effects of traditional chinese medicine in heart failure by complex intervention: protocol of SECETCM-HF

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    <p>Abstract</p> <p>Background</p> <p>Experts in Traditional Chinese Medicine (TCM) have studied the TCM subject of the pathogenesis of heart failure (HF) for several decades. As a result, the general idea is <it>ben </it>deficiency and <it>biao </it>excess. However, the clinical evaluation system which combined the TCM and western medicine in HF has not been developed yet. The objective is to establish the evaluation index system for the integration of TCM and western medicine. The evaluation indexes which include TCM items will specify the research design and methods.</p> <p>Methods</p> <p>Nine medical centers in different cities in China will participate in the trial. A population of 340 patients with HF will be enrolled through a central randomized system for different test groups. Group A will be treated with only western medicine, while group B with western and Chinese medicine together. The study will last for 12 months from the date of enrollment. The cardiovascular death will be the primary outcome.</p> <p>Discussion</p> <p>By putting the protocol into practice, the clinical effects of TCM for HF will be identified scientifically, objectively as well as rationally. The proper index system which built in the study will be helpful for the clinical effect expression of HF by integrated medicine in future.</p> <p>Trial Registration</p> <p>ChiCTR-TRC-00000059</p
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