1,509 research outputs found

    Synthesis and properties of interaction product of rosin and diethylenetriamine

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    Amides of rosin resin acids are a promising material for use in the technology of paper and cardboard in order to increase its strength characteristics. Therefore product of rosin resin acids interaction with diethylenetriamine arouses interest. The influence of temperature and duration of the process of interaction of rosin resin acids with diethylenetriamine on the acid number of the product are examined in this article. Melting point of the received rosin amides was defined. The thermal stability of the reaction product of abietic acid with diethylenetriamine was studied. It was proved that this product contains the appropriate functional groups using IRspectroscopy

    The integration of the accounting system for implementing world class manufacturing (WCM) principles

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    This article covers relevant issues of the development of accounting information system using the principles of integrated information space under implementation of WCM management technology. High-class internationally acknowledged business affects the key approaches to implementing social, ecological and business-processes as well as information space of economic actors. Principles underlying WCM are constant improvement and elimination of waste. In this situation, the studies oriented toward the development of theoretic and methodological projects and applications for integrating accounting systems of the economic actors into one system become especially relevant. Analysis of theoretical and methodological approaches to solving this problem demonstrated that currently the issues of formation and development of the accounting system remain open. Current model of accounting system in the Russian Federation faces contradictions between new requirements and limited possibilities of the methods of traditional accounting and, consequently, the existence of qualitative, quantitative and structural changes in the development of the accounting system. Today in Russian companies there is a great number of types of accounting with a well-defined functional segment: operational, financial, managerial, statistical, fiscal as well as accounting principles IFRS/GAAP. This separation causes obstacles in the management information system and in transition to the principles WCM, creation of several duplicative uncoordinated large data of internal reporting: in parent company and its subsidiaries, head office and structural divisions of the company etc. The aim of the study is to develop methodological and methodical approaches to forming an integrated accounting system using unproductive costs and loss as an example.peer-reviewe

    Gradients of metallicity and age of stars in the dwarf spheroidal galaxies KKs3 and ESO269-66

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    We compare the properties of the stellar populations of the globular clusters and field stars in two dwarf spheroidal galaxies (dSphs): ESO269-66, a near neighbor of the giant S0 galaxy NGC 5128, and KKs3, one of the few extremely isolated dSphs within 10 Mpc. The histories of star formation in these galaxies are known from previous work on deep stellar photometry using images from the Hubble Space Telescope (HST). The age and metal content for the nuclear globular clusters in KKs3 and ESO269-66 are known from literature spectroscopic studies: T=12.6 billion years, [Fe/H]=-1.5 and -1.55 dex. We use the Sersic function to construct and analyze the profiles of the surface density of the stars with high and low metallicities (red and blue) in KKs3 and ESO269-66, and show that (1) the profiles of the density of red stars are steeper than those of blue stars, which is indicative of gradients of metallicity and age in the galaxies, and (2) the globular clusters in KKs3 and ESO269-66 contain roughly 4 and 40%, respectively, of all the old stars in the galaxies with metallicities [Fe/H]~-1.5 to -1.6 dex and ages of 12-14 billion years. The globular clusters are, therefore, relicts of the first, most powerful bursts of star formation in the central regions of these objects. It is probable that, because of its isolation, KKs3 has lost a smaller fraction of old low-metallicity stars than ESO269-66.Comment: 7 pages, 2 figures, 3 table

    A four-subunit DNA polymerase ζ complex containing Pol δ accessory subunits is essential for PCNA-mediated mutagenesis

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    DNA polymerase ζ (Pol ζ) plays a key role in DNA translesion synthesis (TLS) and mutagenesis in eukaryotes. Previously, a two-subunit Rev3–Rev7 complex had been identified as the minimal assembly required for catalytic activity in vitro. Herein, we show that Saccharomyces cerevisiae Pol ζ binds to the Pol31 and Pol32 subunits of Pol δ, forming a four-subunit Pol ζ(4) complex (Rev3–Rev7–Pol31–Pol32). A [4Fe-4S] cluster in Rev3 is essential for the formation of Pol ζ(4) and damage-induced mutagenesis. Pol32 is indispensible for complex formation, providing an explanation for the long-standing observation that pol32Δ strains are defective for mutagenesis. The Pol31 and Pol32 subunits are also required for proliferating cell nuclear antigen (PCNA)-dependent TLS by Pol ζ as Pol ζ(2) lacks functional interactions with PCNA. Mutation of the C-terminal PCNA-interaction motif in Pol32 attenuates PCNA-dependent TLS in vitro and mutagenesis in vivo. Furthermore, a mutant form of PCNA, encoded by the mutagenesis-defective pol30-113 mutant, fails to stimulate Pol ζ(4) activity, providing an explanation for the observed mutagenesis phenotype. A stable Pol ζ(4) complex can be identified in all phases of the cell cycle suggesting that this complex is not regulated at the level of protein interactions between Rev3-Rev7 and Pol31-Pol32

    Fingerprints of Spin-Orbital Physics in Crystalline O2_2

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    The alkali hyperoxide KO2_2 is a molecular analog of strongly-correlated systems, comprising of orbitally degenerate magnetic O2_2^- ions. Using first-principles electronic structure calculations, we set up an effective spin-orbital model for the low-energy \textit{molecular} orbitals and argue that many anomalous properties of KO2_2 replicate the status of its orbital system in various temperature regimes.Comment: 4 pages, 2 figures, 1 tabl

    The Evolutionary Status of Isolated Dwarf Irregular Galaxies II. Star Formation Histories and Gas Depletion

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    The results of UBV and H alpha imaging of a large sample of isolated dwarf irregular galaxies are interpreted in the context of composite stellar population models. The observed optical colors are best fit by composite stellar populations which have had approximately constant star formation rates for at least 10 Gyr. The galaxies span a range of central surface brightness, from 20.5 to 25.0 mag arcsec^{-2}; there is no correlation between surface brightness and star formation history. Although the current star formation rates are low, it is possible to reproduce the observed luminosities without a major starburst episode. The derived gas depletion timescales are long, typically ~20 Gyr. These results indicate that dwarf irregular galaxies will be able to continue with their slow, but constant, star formation activity for at least another Hubble time. The sample of isolated dIs is compared to a sample of star bursting dwarf galaxies taken from the literature. The star bursting dwarf galaxies have many similar properties; the main difference between these two types of gas-rich dwarf galaxies is that the current star formation is concentrated in the center of the star bursting systems while it is much more distributed in the quiescent dIs. This results in pronounced color gradients for the starbursting dwarf galaxies, while the majority of the quiescent dwarf irregular galaxies have minor or non-existent color gradients. Thus, the combination of low current star formation rates, blue colors, and the lack of significant color gradients indicates that star formation percolates slowly across the disk of normal dwarf galaxies in a quasi-continuous manner.Comment: 16 pages, uses emulateapj, to appear in The Astronomical Journal (April 2001

    Improved genome editing in human cell lines using the CRISPR method

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    The Cas9/CRISPR system has become a popular choice for genome editing. In this system, binding of a single guide (sg) RNA to a cognate genomic sequence enables the Cas9 nuclease to induce a double-strand break at that locus. This break is next repaired by an error-prone mechanism, leading to mutation and gene disruption. In this study we describe a range of refinements of the method, including stable cell lines expressing Cas9, and a PCR based protocol for the generation of the sgRNA. We also describe a simple methodology that allows both elimination of Cas9 from cells after gene disruption and re-introduction of the disrupted gene. This advance enables easy assessment of the off target effects associated with gene disruption, as well as phenotype-based structure-function analysis. In our study, we used the Fan1 DNA repair gene as control in these experiments. Cas9/CRISPR-mediated Fan1 disruption occurred at frequencies of around 29%, and resulted in the anticipated spectrum of genotoxin hypersensitivity, which was rescued by re-introduction of Fan1

    No ntuberculous Mycobacteria

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    There has been a sharp increase in the number of diseases associated with potentially pathogenic microorganisms of the genus Mycobacterium, which differ from Mycobacterium tuberculosis. These bacteria are known as atypical mycobacteria or nontuberculosis mycobacteria (NTM), and the diseases they cause are called mycobacteriosis. NTMs include more than 20 species of acid-resistant microorganisms that are widespread in the environment and that are not members of the M. tuberculosis complex. However, the role of certain types of NTMs in the pathogenesis of human diseases is rather ambiguous. The aim of the paper was to analyse the current rise in the incidence of NTM diseases, as well as the main areas of research on early diagnosis of mycobacteriosis and the detection and testing of drug susceptibility of these microorganisms. The paper summarises current views on NTM species differences, their prevalence and pathogenicity for humans and animals. The authors analysed the main efforts aimed at diagnosis and treatment of NTM diseases. The paper cites the results of the study of NTM susceptibility/resistance to anti-tuberculosis drugs. The diagnosis of mycobacteriosis remains extremely difficult, mainly because of the similarity of the clinico-radiological evidence with that of tuberculosis. Detection of NTM multiple and extensive drug resistance to the majority of anti-tuberculosis drugs complicates the treatment of the NTM disease. Further study of various aspects of NTM diseases is especially important given the increase in the incidence and prevalence of mycobacteriosis all over the world, challenging differential diagnosis, and detection of NTM extensive drug resistance
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