J Colloid Interface Sci
February 2022
The use of glassceramics in photocatalysis is an attractive option for the realization of smart optical fibers and self-cleaning windows. Here we present the photocatalytic activity of germanosilicate glasses embedding GaO nanocrystals prepared by batch melting and glass heat treatment. The powdered material is used for UV-assisted degradation of rhodamine in water.
View Article and Find Full Text PDFWe report the one-step precipitation of CdS quantum dots in the volume of CdS-doped silicate glass under the focused femtosecond laser beam without additional heat treatment of glass. Femtosecond direct laser writing leads to the annular distribution of the precipitated CdS quantum dots in laser-written domain optical properties of which could be tuned by laser beam parameters. Increasing the laser pulse number to 10 significantly enhances luminescence intensity in the domains, while further increasing up to 10 pulses leads to luminescence quenching.
View Article and Find Full Text PDFComparative in vitro study examined the osteogenic potential of interstitial cells of aortic valve obtained from the patients with aortic stenosis and from control recipients of orthotopic heart transplantation with intact aortic valve. The osteogenic inductors augmented mineralization of aortic valve interstitial cells (AVIC) in patients with aortic stenosis in comparison with the control level. Native AVIC culture of aortic stenosis patients demonstrated overexpression of osteopontin gene (OPN) and underexpression of osteoprotegerin gene (OPG) in comparison with control levels.
View Article and Find Full Text PDFIn this Letter, we present detailed absorption and emission data on nanostructured germanosilicate glasses and glass ceramics containing GaO nanophases and doped with Gd ions. The results show that these systems are suitable hosts for the enhancement of the excitation cross section of rare earth ions via energy transfer from the gallium oxide nanophase with a related quantum yield of 21%. The role of matrix composition and nanostructure morphology on the Gd emission is discussed.
View Article and Find Full Text PDFIncorporation of doping ions in nanocrystals is a strategy for providing nanophases with functions directly related to ion features. At the nanoscale, however, doping can also activate more complex effects mediated by perturbation of the nanophase size and structure. Here, we report a paradigmatic case in which we modify grown-in-glass γ-Ga O nanophases by nickel or titanium doping of the starting glass, so as to control the concentration of oxygen and gallium vacancies responsible for the light emission.
View Article and Find Full Text PDFPhys Chem Chem Phys
February 2015
Phase transformations at the nanoscale represent a challenging field of research, mainly in the case of nanocrystals (NCs) in a solid host, with size-effects and interactions with the matrix. Here we report the study of the structural evolution of γ-Ga2O3 NCs in alkali-germanosilicate glass - a technologically relevant system for its light emission and UV-to-visible conversion - showing an evolution drastically different from the expected transformation of γ-Ga2O3 into β-Ga2O3. Differential scanning calorimetry registers an irreversible endothermic process at ∼1300 K, well above the exothermic peak of γ-Ga2O3 nano-crystallization (∼960 K) and below the melting temperature (∼1620 K).
View Article and Find Full Text PDFDeaths of extremely premature babies undiagnosed as having spontaneous chylopericardium (CP) and chylothorax (CT) are analyzed. The specific features of these death cases are the polyetiology of CP/CT and the similarity of their pathogenesis in the absence of specific clinical symptomatology.
View Article and Find Full Text PDFNuclear lamins are the major proteins of nuclear envelope and provide the strength of nuclear membrane as well as the interaction of extra-nuclear structures with components of cell nucleus. Recently, it became clear that lamins not only play a structural role in the cell, but could also regulate cell fate, for example lamins could influence cell differentiation via interaction with components of the Notch signaling pathway. Human mutations in LMNA, encoding lamin A/C lead to diseases commonly referred to as laminopathies.
View Article and Find Full Text PDFWide-bandgap nanocrystals are an inexhaustible source of tuneable functions potentially addressing most of the demand for new light emitting systems. However, the implementation of nanocrystal properties in real devices is not straightforward if a robust and stable optical component is required as a final result. The achievement of efficient light emission from dense dispersions of Ga-oxide nanocrystals in UV-grade glass can be a breakthrough in this regard.
View Article and Find Full Text PDFKey aspects of gene transcription regulation in multicellular organisms, including the characteristics of their promoters, transcription-factor binding sites, and composition elements are reviewed. The functional role of transcription regulatory proteins (basal factors and regulatory transcription factors), and the mechanisms responsible for regulation of their activity are also discussed. Furthermore, we describe the importance of DNA-encoded nucleosome organization and chromatin modifications in the course of transcription regulation, as well as some mechanisms that regulate the activity of transcription factors associated with genetic networks.
View Article and Find Full Text PDFIn this Letter, we show functionalization of NiO-doped 7.5Li(2)O·2.5Na(2)O·20Ga(2)O(3)·35SiO(2)·35GeO(2) glass by space-selective nanocrystallization via exposure to the focused beam of a pulsed copper vapor laser (510.
View Article and Find Full Text PDFNanoparticles in amorphous oxides are a powerful tool for embedding a wide range of functions in optical glasses, which are still the best solutions in several applications in the ever growing field of photonics. However, the control of the nanoparticle size inside the host material is often a challenging task, even more challenging when detrimental effects on light transmittance have to be avoided. Here we show how the process of phase separation and subsequent nanocrystallization of a Ga-oxide phase can be controlled in germanosilicates - prototypal systems in optical telecommunications - starting from a Ga-modified glass composition designed to favour uniform liquid-liquid phase separation in the melt.
View Article and Find Full Text PDFA spectroscopic protocol is proposed to implement confocal microfluorescence imaging to the analysis of microinhomogeneity in the nanocrystallization of the core of fibers belonging to a new kind of broadband fiber amplifier based on glass with embedded nanocrystals. Nanocrystallization, crucial for achieving an adequate light emission efficiency of transition metal ions in these materials, has to be as homogeneous as possible in the fiber to assure optical amplification. This requirement calls for a sensitive method for monitoring nanostructuring in oxide glasses.
View Article and Find Full Text PDFThe target of taking advantage of the near-infrared light-emission properties of nickel ions in crystals for the design of novel broadband optical amplifiers requires the identification of suitable nanostructured glasses able to embed Ni-doped nanocrystals and to preserve the workability of a glass. Here we show that Ni doping of Li(2)O-Na(2)O-Ga(2)O(3)-GeO(2)-SiO(2) glass (with composition 7.5:2.
View Article and Find Full Text PDFInsulin is the important regulator of adipose cell metabolism and activates the branched out network of the signaling pathways supervising glucose transport, glycogen synthesis, lipogenesis stimulation, lipolysis inhibition and adipokine secretion. The purpose of our work is the analysis of structure of regulatory contours providing the response of mammalian adipocytes to insulin. With use of computer technology GeneNet adipocyte regulatory-effector network has been reconstructed.
View Article and Find Full Text PDFA new approach, SiteGA, for the prediction of functional transcription factor binding sites has been developed. The approach is based on the detection of locally positioned dinucleotides by the genetic algorithm and discriminant analysis. The approach has been applied to recognize transcription factor binding sites involved in the regulation of immune responses and cell growth (AP-1, IRF1, ISGF3, NFkappaB, STAT1), obesity and lipid metabolism (HNF4, PPAR, SREBP), and the expression of steroidogenesis genes (SF-1).
View Article and Find Full Text PDFThe SF-1 (Steroidogenic Factor-1) is a transcription factor known as a key regulator of the steroidogenic gene expression. SF-1 is required for the development and functioning at all levels of the hypothalamic-pituitary-gonadal and adrenal axis. Also it plays an essential role in sex determination.
View Article and Find Full Text PDFA complex approach to recognize transcription factor binding sites (TFBS) has been developed based on four methods: (i) weight matrix, (ii) information content, (iii) multidimensional alignment, and (iv) pairwise alignment with the most similar representative of known sites. It has been shown that no method optimal for all kinds of sites occurs among the considered methods, so in each case, the appropriate way of recognition should be chosen. The approach proposed allows one to minimize the errors of TFBS recognition.
View Article and Find Full Text PDFThe structure of the Transcription Regulatory Regions Database (TRRD) and the principles of considering transcription regulation of eukaryotic genes in TRRD are concerned. Formal description of the structural and functional organization of the regulatory gene regions is illustrated with examples. By now, TRRD is based on 3500 original works and contains data on transcription regulation of more than 1100 genes known to possess more than 5000 transcription factor-binding sites and about 1600 regulatory elements (promoters, enhancers, silencers).
View Article and Find Full Text PDFDevelopment of methods for mathematical simulation of biological systems and building specific simulations is an important trend of bioinformatics development. Here we describe the method of generalized chemokinetic simulation generating flexible and adequate simulations of various biological systems. Adequate simulations of complex nonlinear gene networks--control system of cholesterol by synthesis in the cell and erythrocyte differentiation and maturation--are given as the examples.
View Article and Find Full Text PDFA hypothesis on the genetic determination of periodic fluctuations of the sensitivity to the mutagen thioTEPA in successive inbred generations of mice has been earlier put forward. This study was the initial stage of testing this hypothesis. The mouse strain CBA/LacY was divided into two substrains, which differed in the rate of generation change.
View Article and Find Full Text PDFMurine myelomas are rare cell variants deficient in inducible isoform of Hsp70 that protects cells from injury. In these cells Hsp70 is absent and is not induced under stress conditions. In this study myeloma cells NS0/1 were transfected with hsp70, and their susceptibility to apoptosis was challenged by serum deprivation or hydrogen peroxide.
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