3,765 research outputs found

    Tetra­pyridine­bis(trichloro­acetato)nickel(II)

    Get PDF
    The title compound, [Ni(C2Cl3O2)2(C5H5N)4], was prepared by the reaction of pyridine and trichloro­acetatonickel(II) in ethanol solution at room temperature. The NiII atom is located on a twofold rotation axis and has a slightly distorted octa­hedral coordination made up of four N atoms of the pyridine ligands and two O atoms of trichloro­acetate anions. The mol­ecular structure and packing are stabilized by intra- and inter­molecular C—H⋯O hydrogen-bonding inter­actions

    Hexaaqua­cobalt(II) bis­{[N-(4-meth­oxy-2-oxidobenzyl­idene)glycyl­glycinato]copper(II)} hexa­hydrate

    Get PDF
    In the crystal structure of the title compound, [Co(H2O)6][Cu(C12H11N2O5)]2·6H2O, the CoII atom is located on an inversion center and coordinated by six water mol­ecules in a slightly distorted octa­hedral geometry. The CuII atom is chelated by the Schiff base ligand in a distorted CuN2O2 square-planar geometry. An extensive O—H⋯O hydrogen-bonding network is present in the crystal structure

    Ball Pad Mold Electromagnetic Forming Process for Aluminium Alloy Sheet

    Get PDF
    In order to meet requirements of lightweight technology in the field of aerospace, the new forming technology for aluminium alloy skin parts and integral panel are brought to more attention. Based on the principle of electromagnetic forming (EMF) and energy distribution, a new electromagnetic forming process using ball as pad mold for aluminium alloy sheet forming was suggested and test apparatus was designed. The new method was verified by the finite element simulation and experimental technology, and all studies were carried out on 2024-T3 aluminium alloy sheet. The results show that the new process of ball pad mold electromagnetic forming is feasible to aluminium alloy sheet parts forming. Rubber cushion thickness and electromagnetic pulse voltage are significant contributors to the curvature radius of the test sample. Based on these observations, application advantages and prospects of this new process were pointed out, and the subsequent research was put forward

    Comparative Cytogenetics Analysis of Chlamys farreri, Patinopecten yessoensis, and Argopecten irradians with C0t-1 DNA by Fluorescence In Situ Hybridization

    Get PDF
    The chromosomes of Chlamys farreri, Patinopecten yessoensis, and Argopecten irradians were studied by FISH using C. farreri C0t-1 DNA probes. The results showed that C0t-1 DNA signals spread on all chromosomes in the three scallops, whereas signal density and intensity were different strikingly. Clustering brighter signals presented in the centromeric and telomeric regions of most C. farreri chromosomes, and in the centromeric or pericentromeric regions of several P. yessoensis chromosomes. Comparative analysis of the mapping indicated a relatively higher homology in the repetitive DNA sequences of the genome between C. farreri and P. yessoensis than that between C. farreri and A. irradians. In addition, FISH showed that the distribution of C0t-1 DNA clustering signals in C. farreri displayed completely similar signal bands between homologous chromosomes. Based on the C0t-1 DNA fluorescent bands, a more exact karyotype of C. farreri has been obtained. In this study, the comparative analysis based on C0t-1 DNA provides a new insight into the chromosomal reconstructions during the evolution process, and it is helpful for understanding an important source of genomic diversity, species relationships, and genome evolution

    Fast SPH simulation for gaseous fluids

    Get PDF
    This paper presents a fast smoothed particle hydro-dynamics (SPH) simulation approach for gaseous fluids. Unlike previous SPH gas simulators, which solve the transparent air flow in a fixed simulation domain, the proposed approach directly solves the visible gas without involving the transparent air. By compensating the density and force calculation for the visible gas particles, we completely avoid the need of computational cost on ambient air particles in previous approaches. This allows the computational resources to be exclusively focused on the visible gas, leading to significant performance improvement of SPH gas simulation. The proposed approach is at least ten times faster than the standard SPH gas simulation strategy and is able to reduce the total particle number by 25–400 times in large open scenes. The proposed approach also enables fast SPH simulation of complex scenes involving liquid–gas transition, such as boiling and evaporation. A particle splitting and merging scheme is proposed to handle the degraded resolution in liquid–gas phase transition. Various examples are provided to demonstrate the effectiveness and efficiency of the proposed approach

    The B0J/ψf0(1370,1500,1710)B^0 \to J/\psi f_0(1370,1500,1710) decays: an opportunity for scalar glueball hunting

    Full text link
    The scalars f0f_0 closest to 1.5 GeV contain the mesons f0(1370)f_0(1370), f0(1500)f_0(1500) and f0(1710)f_0(1710), and the latter two ones are usually viewed as the potential candidates for the scalar glueballs. In this work, by including the important contributions from the vertex corrections, we study the decays B0J/ψf0B^0 \to J/\psi f_0 within the improved perturbative QCD approach and analyze the possible scalar glueball hunting. Together with the two mixing models, namely, f0(1500)(f0(1710))f_0(1500) (f_0(1710)) being the primary scalar glueball in model I (II), and two classification scenarios, namely, f0f_0 being the qqˉq\bar q excited (ground) states in scenario 1 (2), the branching fractions associated with their ratios for B0J/ψf0B^0 \to J/\psi f_0 are evaluated comprehensively. The predictions with still large uncertainties in the considered two mixing models are roughly consistent with currently limited data, which indicates that both more rich data and more precise predictions are urgently demanded to figure out the scalar glueball clearly in the future. Moreover, several interesting ratios between the branching fractions of B0J/ψf0(π+π/K+K)B^0 \to J/\psi f_0(\to \pi^+ \pi^-/K^+ K^-) and B0J/ψρ0/ϕ(π+π/K+K)B^0 \to J/\psi \rho^0/\phi (\to \pi^+ \pi^-/ K^+ K^-) that could help us to understand the nature of scalar f0f_0 are defined and predicted theoretically. These ratios should be examined in future experiments.Comment: 28 pages, 3 figures, 6 tables; revised version according to referee's comments; contents improved and references adde

    Role of miR-1 and miR-133a in myocardial ischemic postconditioning

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>Ischemic postconditioning (IPost) has aroused much attention since 2003 when it was firstly reported. The role of microRNAs (miRNAs or miRs) in IPost has rarely been reported. The present study was undertaken to investigate whether miRNAs were involved in the protective effect of IPost against myocardial ischemia-reperfusion (IR) injury and the probable mechanisms involved.</p> <p>Methods</p> <p>Thirty SD rats weighing 250-300 g were equally randomized to three groups: Control group, where the rats were treated with thoracotomy only; IR group, where the rats were treated with ischemia for 60 min and reperfusion for 180 min; and IPost group, where the rats were treated with 3 cycles of transient IR just before reperfusion. The extent of myocardial infarction, LDH and CK activities were measured immediately after treatment. Myocardial apoptosis was detected by TUNEL assay. The myocardial tissue was collected after IR or IPost stimulation to evaluate the miRNAs expression level by miRNA-microarray and quantitative real-time RT-PCR. Real-time PCR was conducted to identify changes in mRNA expression of apoptosis-related genes such as Bcl-2, Bax and Caspase-9 (CASP9), and Western blot was used to compare the protein expression level of CASP9 in the three groups. The miRNA mimics and anti-miRNA oligonucleotides (AMO) were transferred into the cultured neonatal cardiomyocytes and myocardium before they were treated with IR. The effect of miRNAs on apoptosis was determined by flow cytometry and TUNEL assay. CASP9, as one of the candidate target of miR-133a, was compared during IR after the miR-133a mimic or AMO-133a was transferred into the myocardium.</p> <p>Results</p> <p>IPost reduced the IR-induced infarct size of the left ventricle, and decreased CK and LDH levels. TUNEL assay showed that myocardial apoptosis was attenuated by IPost compared with IR. MiRNA-microarray and RT-PCR showed that myocardial-specific miR-1 and miR-133a were down-regulated by IR, and up-regulated by IPost compared with IR. Furthermore, IPost up-regulated the mRNA expression of Bcl-2, down-regulated that of Bax and CASP9. Western blot showed that IPost also down-regulated the CASP9 protein expression compared with IR. The results of flow cytometry and TUNEL assay showed that up-regulation of miR-1 and miR-133a decreased apoptosis of cardiomyocytes. MiR-133a mimic down-regulated CASP9 protein expression and attenuated IR-induced apoptosis.</p> <p>Conclusion</p> <p>MiRNAs are associated with the protective effect of IPost against myocardial IR injury. IPost can up-regulate miR-1 and miR-133a, and decrease apoptosis of cardiomyocyte. Myocardial-specific miR-1 and miR-133a may play an important role in IPost protection by regulating apoptosis-related genes. MiR-133a may attenuate apoptosis of myocardiocytes by targeting CASP9.</p
    corecore