53 research outputs found

    Di-μ-benzoato-κ3 O,O′:O;κ3 O:O,O′-bis­[(acetato-κO)(1,10-phenanthroline-κ2 N,N′)lead(II)] dihydrate

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    The title compound, [Pb2(CH3COO)2(C7H5O2)2(C12H8N2)2]·2H2O, consists of dimeric units built up around a crystallographic centre of symmetry and two non-coordinating water mol­ecules. Each PbII unit is six-coordinated by a bidentate 1,10-phenanthroline (phen) ligand, a monodentate acetate anion and a bidentate benzoate anion, which also acts as a bridge linking the two PbII atoms. The crystal packing is stabilized by O—H⋯O hydrogen bonds and by π–π inter­actions between the phen rings of neighboring mol­ecules, with a centroid–centroid distance of 3.577 (3) Å

    Measurement of the extinction coefficients of magnetic fluids

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    A novel spectral transmittance approach for measuring the extinction coefficient of magnetic fluids is proposed. The measuring principle and accuracy of the approach are analysed. Experiments are conducted to measure the extinction coefficient of magnetic fluids with different particle volume fractions. The relative uncertainty of experimental data is less than 1.8%. The experimental results indicate that the extinction coefficient of magnetic fluids increases with increase of the volume fraction of suspended magnetic nanoparticles and the optical properties of the particle material have a significant effect on the extinction coefficient of the magnetic fluids

    Estimating the Quality of Reprogrammed Cells Using ES Cell Differentiation Expression Patterns

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    Somatic cells can be reprogrammed to a pluripotent state by over-expression of defined factors, and pluripotency has been confirmed by the tetraploid complementation assay. However, especially in human cells, estimating the quality of Induced Pluripotent Stem Cell(iPSC) is still difficult. Here, we present a novel supervised method for the assessment of the quality of iPSCs by estimating the gene expression profile using a 2-D “Differentiation-index coordinate”, which consists of two “developing lines” that reflects the directions of ES cell differentiation and the changes of cell states during differentiation. By applying a novel liner model to describe the differentiation trajectory, we transformed the ES cell differentiation time-course expression profiles to linear “developing lines”; and use these lines to construct the 2-D “Differentiation-index coordinate” of mouse and human. We compared the published gene expression profiles of iPSCs, ESCs and fibroblasts in mouse and human “Differentiation-index coordinate”. Moreover, we defined the Distance index to indicate the qualities of iPS cells, which based on the projection distance of iPSCs-ESCs and iPSCs-fibroblasts. The results indicated that the “Differentiation-index coordinate” can distinguish differentiation states of the different cells types. Furthermore, by applying this method to the analysis of expression profiles in the tetraploid complementation assay, we showed that the Distance index which reflected spatial distributions correlated the pluripotency of iPSCs. We also analyzed the significantly changed gene sets of “developing lines”. The results suggest that the method presented here is not only suitable for the estimation of the quality of iPS cells based on expression profiles, but also is a new approach to analyze time-resolved experimental data

    Serum Oxytocin Levels and an Oxytocin Receptor Gene Polymorphism (rs2254298) Indicate Social Deficits in Children and Adolescents with Autism Spectrum Disorders

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    The neuropeptide oxytocin (OT) and its receptor (OXTR) have been predicted to be involved in the regulation of social functioning in autism spectrum disorders (ASD). Objective of the study was to investigate serum OT levels and the OXTR rs2254298 polymorphism in Chinese Han children and adolescents with ASD as well as to identify their social deficits relevant to the oxytocinergic system. We tested serum OT levels using ELISA in 55 ASD subjects and 110 typically developing (TD) controls as well as genotyped the OXTR rs2254298 polymorphism using PCR-RFLP in 100 ASD subjects and 232 TD controls. Autistic symptoms were assessed by the Autism Behavior Checklist (ABC) and the Childhood Autism Rating Scale (CARS). There were no significant associations between OXTR rs2254298 polymorphism and ASD, serum OT levels and age, as well as serum OT levels and intelligent quotient (IQ) in both ASD and TD groups. However, ASD subjects exhibited elevated serum OT levels compared to TD controls and positive correlations between serum OT levels and adaptation to change score in the CARS and CARS total scores. Moreover, in the ASD group, significant relationships were revealed between the single-nucleotide polymorphism (SNP) rs2254298 and serum OT levels, the category stereotypes and object use in the ABC and the category adaptation to change in the CARS. These findings indicated that individuals with ASD may exhibit a dysregulation in OT on the basis of changes in OXTR gene expression as well as environmentally induced alterations of the oxytocinergic system to determine their social deficits

    Acetate suppresses myocardial contraction via the short-chain fatty acid receptor GPR43

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    The heart has high energy requirements, with an estimated 40%–60% of myocardial ATP production derived from the oxidation of fatty acids under physiological conditions. However, the effect of short-chain fatty acids on myocardial contraction remains controversial, warranting further research. The present study sought to investigate the effects and mechanisms of acetate, a short-chain fatty acid, on myocardial contraction in rat ventricular myocytes. Echocardiography and Langendorff heart perfusion were used to evaluate cardiac function. Cell shortening and calcium transient were measured in isolated cardiomyocytes. The patch-clamp method determined the action potential and L-type Ca2+ current in cardiomyocytes. Moreover, the expression of GPR43, a type of short-chain fatty acid receptors in cardiomyocytes was examined by immunofluorescent staining and Western blot. We demonstrated that acetate transiently reduced left ventricular developmental pressure in isolated Langendorff heart perfusion model, with no effect on stroke volume and cardiac output in vivo. In addition, acetate transiently and reversibly inhibited cardiomyocyte contraction and calcium transient. Acetate did not affect the action potential and L-type Ca2+ currents in cardiomyocytes. As a short-chain fatty acid receptor, GPR43 was expressed in rat cardiomyocytes. Furthermore, the GPR43 antagonist GLPG0974 prevented the acetate-induced inhibitory effect on myocardial contraction. We conclude that acetate transiently inhibits contraction via the short-chain fatty acid receptor GPR43 in cardiomyocytes

    IMPACT OF STRESS MULTI-AXIAL EFFECT ON 316 STAINLESS STEEL CREEP DESIGN MARGIN

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    ASME NH high-temperature design code put limits on inelastic strain. However,there are several arguments about this provision. For instance,the multi-axial effect and different design margins for different materials were not considered.In this paper,a 316 stainless steel 90°elbow at 550℃ was simulated to study impact of multi-axial effect on creep design strain margin. A continuum damage constitutive model was used,also new damage variables were defined based on multi-axial creep ductility theory. These damage variables were investigated when strains of the elbow reached corresponding limits in order to judge whether ASME NH strain limits are conservative. It is shown that all the damage variables are well below unity when the membrane strain of the elbow reaches the strain limits of 1%. It is thus concluded that ASME NH strain limits is still conservative when multi-axial effect is considered in a 316 stainless steel structure and can be used for design and verification at this temperature

    Measurement of the extinction coefficients of magnetic fluids

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    Abstract A novel spectral transmittance approach for measuring the extinction coefficient of magnetic fluids is proposed. The measuring principle and accuracy of the approach are analysed. Experiments are conducted to measure the extinction coefficient of magnetic fluids with different particle volume fractions. The relative uncertainty of experimental data is less than 1.8%. The experimental results indicate that the extinction coefficient of magnetic fluids increases with increase of the volume fraction of suspended magnetic nanoparticles and the optical properties of the particle material have a significant effect on the extinction coefficient of the magnetic fluids.</p

    Polarization 3D imaging technology: a review

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    Polarization three-dimensional (3D) imaging technology has received extensive attention in recent years because of its advantages of high accuracy, long detection distance, simplicity, and low cost. The ambiguity in the normal obtained by the polarization characteristics of the target’s specular or diffuse reflected light limits the development of polarization 3D imaging technology. Over the past few decades, many shape from polarization techniques have been proposed to address the ambiguity issues, i.e., high-precision normal acquisition. Meanwhile, some polarization 3D imaging techniques attempt to extend experimental objects to complex specific targets and scenarios through a learning-based approach. Additionally, other problems and related solutions in polarization 3D imaging technology are also investigated. In this paper, the fundamental principles behind these technologies will be elucidated, experimental results will be presented to demonstrate the capabilities and limitations of these popular technologies, and finally, our perspectives on the remaining challenges of the polarization 3D imaging technology will be presented

    Advanced Visualization Polarimetric Imaging: Removal of Water Spray Effect Utilizing Circular Polarization

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    Circular polarization (CP) memory is a well-known phenomenon whereby natural light becomes partially circularly polarized after scattering by water spray several times, and the circularly polarized state can be well preserved within a certain propagation distance. In this study, a CP imaging method combined with the multi-scale analysis in the frequency domain is proposed to enhance the vision in rainy conditions. The images were first decomposed into multi-scales. CP characteristics of light were employed in the low-frequency parts to improve the quality of images in rainy conditions, and the high-frequency parts compensated specific structure information. Experimental results demonstrate that the proposed method can remove the water spray effect thereby improving the vision of degraded rainy-day images
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