Исполнительные механизмы самонаклада с нижним выводом полуфабриката, проблемы и пути их устранения

У статті приведені огляд та результати параметричного дослідження виконавчих механізмів самонакладів з нижнім виводом напівфабрикату. Запропоновано нові виконавчі механізми, які раніше не застосовувались.In the article kinematic examination of feeder mechanisms were made. New type scheme for this machines was offer.В статье проведен обзор и результаты параметрического исследования исходных механизмов самонакладов с нижним выводом полуфабриката. Предложены новые механизмы, ранее не используемые

5-hydroxymethyl-cytosine enrichment of non-committed cells is not a universal feature of vertebrate development

5-hydroxymethyl-cytosine (5-hmC) is a cytosine modification that is relatively abundant in mammalian pre-implantation embryos and embryonic stem cells (ESC) derived from mammalian blastocysts. Recent observations imply that both 5-hmC and Tet1/2/3 proteins, catalyzing the conversion of 5-methyl-cytosine to 5-hmC, may play an important role in self renewal and differentiation of ESCs. Here we assessed the distribution of 5-hmC in zebrafish and chick embryos and found that, unlike in mammals, 5-hmC is immunochemically undetectable in these systems before the onset of organogenesis. In addition, Tet1/2/3 transcripts are either low or undetectable at corresponding stages of zebrafish development. However, 5-hmC is enriched in later zebrafish and chick embryos and exhibits tissue-specific distribution in adult zebrafish. Our findings show that 5-hmC enrichment of non-committed cells is not a universal feature of vertebrate development and give insights both into evolution of embryonic pluripotency and the potential role of 5-hmC in its regulation. © 2012 Landes Bioscience

The contribution of financial entities to the sustainable development through the reporting of corporate social responsibility information

This paper aims at examining the relationship between board composition and corporate social responsibility (CSR) of a sample of listed financial entities, discussing the driving reasons of these entities to disclose CSR information. We hypothesize that there is a positive association between outside (institutional and independent directors) and female directors and CSR disclosure and a negative relationship between inside directors and CSR reporting. Our findings provide evidence that the proportions of independent directors and female directors on boards encourage CSR disclosure. Moreover, the results also show that the proportions of inside directors and institutional directors on boards do not have influence on CSR reporting. Thus, our evidence suggests that board attributes such as independent and female directors encourage financial entities to report CSR matters, showing the effectiveness of these two corporate governance mechanisms. The paper shed light on the influence of board structure of financial entities on CSR disclosure. Therefore, this study contributes to past research by providing an index to measure CSR disclosure of financial entities and the importance of the distinction between outside and inside directors

A comprehensive TALEN-based knockout library for generating human induced pluripotent stem cell-based models for cardiovascular diseases

Rationale: Targeted genetic engineering using programmable nucleases such as transcription activator-like effector nucleases (TALENs) is a valuable tool for precise, site-specific genetic modification in the human genome. Objective: The emergence of novel technologies such as human induced pluripotent stem cells (iPSCs) and nuclease-mediated genome editing represent a unique opportunity for studying cardiovascular diseases in vitro. Methods and Results: By incorporating extensive literature and database searches, we designed a collection of TALEN constructs to knockout (KO) eighty-eight human genes that are associated with cardiomyopathies and congenital heart diseases. The TALEN pairs were designed to induce double-strand DNA break near the starting codon of each gene that either disrupted the start codon or introduced a frameshift mutation in the early coding region, ensuring faithful gene KO. We observed that all the constructs were active and disrupted the target locus at high frequencies. To illustrate the general utility of the TALEN-mediated KO technique, six individual genes (TNNT2, LMNA/C, TBX5, MYH7, ANKRD1, and NKX2.5) were knocked out with high efficiency and specificity in human iPSCs. By selectively targeting a dilated cardiomyopathy (DCM)-causing mutation (TNNT2 p.R173W) in patient-specific iPSC-derived cardiac myocytes (iPSC-CMs), we demonstrated that the KO strategy ameliorates the DCM phenotype in vitro. In addition, we modeled the Holt-Oram syndrome (HOS) in iPSC-CMs in vitro and uncovered novel pathways regulated by TBX5 in human cardiac myocyte development. Conclusions: Collectively, our study illustrates the powerful combination of iPSCs and genome editing technology for understanding the biological function of genes and the pathological significance of genetic variants in human cardiovascular diseases. The methods, strategies, constructs and iPSC lines developed in this study provide a validated, readily available resource for cardiovascular research

Protocol for the Arterial Revascularisation Trial (ART). A randomised trial to compare survival following bilateral versus single internal mammary grafting in coronary revascularisation [ISRCTN46552265]

BACKGROUND: Standard coronary artery bypass graft surgery uses a single internal mammary artery and supplemental vein or radial artery grafts. Several observational studies have suggested a survival benefit with two internal mammary artery grafts compared to a single internal mammary artery graft, but this has not been tested in a randomised trial. The Arterial Revascularisation Trial is a Medical Research Council and British Heart Foundation funded, multi-centre international trial comparing single internal mammary artery grafting versus bilateral internal mammary artery grafting. METHODS/DESIGN: Twenty centres in the UK, Australia, Poland and Brazil are planning to randomise 3000 coronary artery bypass graft surgery patients to single or bilateral internal mammary artery grafting. Supplemental grafts may be either saphenous vein or radial artery. Coronary artery bypass grafting can be performed as an on-pump or off-pump procedure. The primary outcome is survival at 10 years and secondary end-points include clinical events, quality of life and cost effectiveness. The effect of age, left ventricular function, diabetes, number of grafts, vein grafts and off-pump surgery are pre-specified subgroups. DISCUSSION: The Arterial Revascularisation Trial is one of the first randomised trials to evaluate the effects on survival and other clinical outcomes of single internal mammary artery grafting versus bilateral internal mammary artery grafting, and will help to establish the best approach for patients requiring coronary artery bypass graft surgery

Advanced maturation of human cardiac tissue grown from pluripotent stem cells

Cardiac tissues generated from human induced pluripotent stem cells (iPSCs) can serve as platforms for patient-specific studies of physiology and disease1-6. However, the predictive power of these models is presently limited by the immature state of the cells1, 2, 5, 6. Here we show that this fundamental limitation can be overcome if cardiac tissues are formed from early-stage iPSC-derived cardiomyocytes soon after the initiation of spontaneous contractions and are subjected to physical conditioning with increasing intensity over time. After only four weeks of culture, for all iPSC lines studied, such tissues displayed adult-like gene expression profiles, remarkably organized ultrastructure, physiological sarcomere length (2.2 µm) and density of mitochondria (30%), the presence of transverse tubules, oxidative metabolism, a positive force-frequency relationship and functional calcium handling. Electromechanical properties developed more slowly and did not achieve the stage of maturity seen in adult human myocardium. Tissue maturity was necessary for achieving physiological responses to isoproterenol and recapitulating pathological hypertrophy, supporting the utility of this tissue model for studies of cardiac development and disease.The authors acknowledge funding support from the National Institutes of Health of the USA (NIBIB and NCATS grant EB17103 (G.V.-N.); NIBIB, NCATS, NIAMS, NIDCR and NIEHS grant EB025765 (G.V.-N.); NHLBI grants HL076485 (G.V.-N.) and HL138486 (M.Y.); Columbia University MD/PhD program (S.P.M., T.C.); University of Minho MD/PhD program (D.T.); Japan Society for the Promotion of Science fellowship (K.M.); and Columbia University Stem Cell Initiative (D.S., L.S., M.Y.). We thank S. Duncan and B. Conklin for providing human iPSCs, M.B. Bouchard for assistance with image and video analysis, and L. Cohen-Gould for transmission electron microscopy services.info:eu-repo/semantics/publishedVersio