894 research outputs found

    Reactivation of the mitosis-promoting factor in postmitotic cardiomyocytes

    Get PDF
    Cardiomyocytes cease to divide shortly after birth and an irreversible cell cycle arrest is evident accompanied by the downregulation of cyclin-dependent kinase activities. To get a better understanding of the cardiac cell cycle and its regulation, the effect of functional recovery of the mitosis-promoting factor (MPF) consisting of cyclin B1 and the cyclin-dependent kinase Cdc2 was assessed in primary cultures of postmitotic ventricular adult rat cardiomyocytes ( ARC). Gene transfer into ARC was achieved using the adenovirus-enhanced transferrinfection system that was characterized by the absence of cytotoxic events. Simultaneous ectopic expression of wild-type versions of cyclin B1 and Cdc2 was sufficient to induce MPF activity. Reestablished MPF resulted in a mitotic phenotype, marked by an abnormal condensation of the nuclei, histone H3 phosphorylation and variable degree of decay of the contractile apparatus. Although a complete cell division was not observed, the results provided conclusive evidence that cell cycle-related events in postmitotic cardiomyocytes could be triggered by genetic intervention downstream of the G1/S checkpoint. This will be of importance to design novel strategies to overcome the proliferation arrest in adult cardiomyocytes

    Comprehensive study on wheat flour quality attributes as influence by different agrotechnical factors

    Get PDF
    Received: November 27th, 2020 ; Accepted: February 2nd, 2021 ; Published: March 2nd, 2021 ; Corresponding author: [email protected] present polyfactorial long-term experiment was conducted to determine the role of different agrotechnical factors, like fertilization, forecrop, year and cultivar on the quality and yield attributes of a classical and a modern winter wheat genotypes. The research gives a complex view of the alteration of the most quality parameters (32) that are rarely done together in a single experiment (n = 96). All the studied factors had a significant effect on some tested properties. First growing season with fair water supply was beneficial for yield (+21.7%) however, the 2nd one with mild weather in spring and average annual precipitation was favourable for quality parameters (HFN: +3%, GI: +19%, GS: -51%, DDT: +22.4%, ST: +24.6%, DS: -14%, PDR: +37.6%, PD: +6%, PMR: +51.5%, PE: +52.7%, W: +25.8%, LV: +16.3%, HI: +13.3%). The optimal fertilizer demand of the different parameters varied to realize the potential of the varieties (N90P68K80 for Y, VWA, PWA, PMR, PE, LV, Mavg, KW and HI; meanwhile N150P113K133 for CP, WGC, ZI, VQN, ST, W and P/L). In the case of suboptimal nutrient supply, the effect of fore crops was significant (Y, CP, DGC, ZI, FE, VQN, DDT, ST, DS, PDR, PMR, PE, Mavg and all alveographic values). Comparing the varieties, GK Öthalom had better fertilizer response attribute (NUECP) and quality parameters, till then Mv Ispán possessed significantly better natural nutrient utilizing property (+22.9%), NUEY and yield (+31.7% in 2019). Summarizing the results, there is a need to put great emphasis on the selection of adapted cultivar and variety-specific agrotechnology practices, also these data contribute to a better understanding of the relationships between the quality parameters

    The Engagement Model of Person-Environment Interaction

    Get PDF
    This article focuses on growth-promoting aspects in the environment, and the authors propose a strength-based, dynamic model of person-environment interaction. The authors begin by briefly discussing the typical recognition of contextual variables in models that rely on the concept of person-environment fit. This is followed by a review of recent approaches to incorporating positive environmental factors in conceptualizations of human functioning. These approaches lead to an alternative model of person-environment interaction in which the engagement construct (i.e., the quality of a person-environment relationship determined by the extent to which negotiation, participation, and evaluation processes occur during the interaction) replaces the static notion of fit. Finally, the authors outline recommendations for overcoming environmental neglect in research, practice, and training

    Application of electronic tongue to discriminate white wines originated from different regions of Hungary

    Get PDF
    In this work, the application of an electronic tongue (ET) based on a specific ion-selective sensor array for discrimination of different white wine types is presented. The electronic tongue equipped with specific sensor array containing seven IFSET sensors was used to analyze wine samples. The obtained ET responses were evaluated using different pattern recognition methods. Principal component analysis (PCA) provides the possibility to identify some initial patterns. Linear discriminant analysis (LDA) was used to build models to separate white wine samples based on wine regions and grape cultivars. The results showed that every group was distinguished from each other with no misclassification error. Furthermore, the sequence of the wine sample groups was similar to the increasing total acidity content. Partial least square (PLS) regression was used to build models for the prediction of the main chemical compositions of the wine samples based on the electronic tongue results. The closest correlation (R2=0.93) was found in case of ‘total acidity’, and the prediction error (RMSEP) was 6.9%. The pH of the wine samples was predicted with good correlation (R2=0.89) but higher prediction error (RMSEP=10.71%) from the electronic tongue results. The ET combining these statistical methods can be applied to determine the origin and variety of the wine samples in easy and quick way

    Synthesis of luminescent europium defects in diamond

    Full text link
    © 2014 Macmillan Publishers Limited. All rights reserved. Lanthanides are vital components in lighting, imaging technologies and future quantum memory applications owing to their narrow optical transitions and long spin coherence times. Recently, diamond has become a pre-eminent platform for the realisation of many experiments in quantum information science. Here we demonstrate a promising approach to incorporate Eu ions into diamond, providing a means to harness the exceptional characteristics of both lanthanides and diamond in a single material. Polyelectrolytes are used to electrostatically assemble Eu(III) chelate molecules on diamond and subsequently chemical vapour deposition is employed for the diamond growth. Fluorescence measurements show that the Eu atoms retain the characteristic optical signature of Eu(III) upon incorporation into the diamond lattice. Computational modelling supports the experimental findings, corroborating that Eu(III) in diamond is a stable configuration. The formed defects demonstrate the outstanding chemical control over the incorporation of impurities into diamond enabled by the electrostatic assembly together with chemical vapour deposition growth

    Physics of intense, high energy radiation effects.

    Get PDF
    This document summarizes the work done in our three-year LDRD project titled 'Physics of Intense, High Energy Radiation Effects.' This LDRD is focused on electrical effects of ionizing radiation at high dose-rates. One major thrust throughout the project has been the radiation-induced conductivity (RIC) produced by the ionizing radiation. Another important consideration has been the electrical effect of dose-enhanced radiation. This transient effect can produce an electromagnetic pulse (EMP). The unifying theme of the project has been the dielectric function. This quantity contains much of the physics covered in this project. For example, the work on transient electrical effects in radiation-induced conductivity (RIC) has been a key focus for the work on the EMP effects. This physics in contained in the dielectric function, which can also be expressed as a conductivity. The transient defects created during a radiation event are also contained, in principle. The energy loss lead the hot electrons and holes is given by the stopping power of ionizing radiation. This information is given by the inverse dielectric function. Finally, the short time atomistic phenomena caused by ionizing radiation can also be considered to be contained within the dielectric function. During the LDRD, meetings about the work were held every week. These discussions involved theorists, experimentalists and engineers. These discussions branched out into the work done in other projects. For example, the work on EMP effects had influence on another project focused on such phenomena in gases. Furthermore, the physics of radiation detectors and radiation dosimeters was often discussed, and these discussions had impact on related projects. Some LDRD-related documents are now stored on a sharepoint site (https://sharepoint.sandia.gov/sites/LDRD-REMS/default.aspx). In the remainder of this document the work is described in catergories but there is much overlap between the atomistic calculations, the continuum calculations and the experiments
    • …
    corecore