Reactivation of the mitosis-promoting factor in postmitotic cardiomyocytes

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

The Role of Seismic Stratigraphy in Understanding Biological Evolution in the Pannonian Lake (SE Europe, Late Miocene)

The combined use of seismic stratigraphy and mollusc biostratigraphy in Late Neogene lacustrine deposits of the Pannonian basin offers three new approaches: First, the comparison of seismic facies and biofacies facilitates to make a distinction between biostratigraphic units and biofacies. Second, seismic datum levels permit crosschecking of discrete (magnetic, radiometric, and biostratigraphic) data, thus dating evolutionary events. Third, seismic monitoring of the sedimentary history of the basin helps in the understanding of the geographic distribution of molluscs (areals of younger forms are more and more restricted, due to progradation)

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

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

Biologically inspired materials for electro-responsive coatings and the photo-oxidation of water

Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Materials Science and Engineering, 2010.Cataloged from PDF version of thesis.Includes bibliographical references (p. 193-202).Evolving out of research on biomineralization, a new field devoted to studying the interactions between inorganic materials and proteins is emerging. In natural systems, proteins are responsible for the assembly of complex hierarchical structures such as the nacre of abalone. Tools such as phage and yeast display libraries have enabled the combinatorial screening of peptides against a multitude of materials to which natural systems typically have no exposure. These techniques have yielded peptides that can bind and assemble technologically relevant materials such as gold and CdS. In this work, combinatorial phage and yeast display libraries are used to identify peptide sequences that bind to electrode materials and metal oxides. As in nature, it is observed that the context of a particular peptide dramatically influences its properties. While a peptide sequence may exhibit good adhesion to a particular surface when displayed on yeast, the same peptide may have little affinity towards that same surface when displayed on bacteriophage. To probe the interactions between peptides and materials in a context-free environment, rationally designed synthetic peptides were screened against a number of inorganic materials. A synthetic peptide, covalently linked to either microspheres, quantum dots, or a polymer, was able to mediate adhesion of those entities to electrode surfaces. In nature, proteins play important roles beyond biomineralization. For example, membrane proteins contain voltage-gated ion channels that open and close in response to a voltage bias. Inspired by the electro-responsive activity of ion channels, the interactions between peptides, surfaces and electric fields was investigated. The peptide sequences that exhibited significant adhesion to metal oxides were dominated by positively charged residues. A high voltage, pulsed electric field was used to overcome the inherent negative charge of the metal oxide electrode surface, thereby controlling peptide adhesion to an electrode surface. Drawing further inspiration from the way nature employs peptides, a synthetic photocatalytic system for water oxidation was developed using photosystem II (PSII) as a model. Proteins form the structural scaffold for PSII, assembling dye molecules as well as the metal-oxo catalytic center; furthermore, peptides play an active role in shuttling charge throughout PSIL. The D1 peptide in PSII is an electro-responsive peptide of sorts, releasing plastiquinone upon the two electron reduction of the molecule. The system developed in this work uses: iridium oxide as a metal-oxo catalyst assembled by a peptide expressed on the M13 bacteriophage; metalloporphyrin photosensitizers that are covalently assembled on the protein framework of the bacteriophage; and a synthetic Ce(IV) dipicolinate electron accepting molecule. The electron accepting molecule, developed to fill the role of plastiquinone in PSII, is believed to be the first non-sacrificial electron acceptor capable of driving the metalloporphyrin-sensitized photocatalytic oxidation of water.by Andrew P. Magyar.Ph.D