Self-healing in dielectric capacitors: a universal method to computationally rate newly introduced energy storage designs.

Metalized-film dielectric capacitors provide lump portions of energy on demand. While the capacities of various capacitor designs are comparable in magnitude, their stabilities make a difference. Dielectric breakdowns - micro-discharges - routinely occur in capacitors due to the inevitable presence of localized structure defects.

Meso-Macroporous Hydroxyapatite Powders Synthesized in Polyvinyl Alcohol or Polyvinylpyrrolidone Media.

Mesoporous hydroxyapatite (HA) is widely used in various applications, such as the biomedical field, as a catalytic, as a sensor, and many others. The aim of this work was to obtain HA powders by means of chemical precipitation in a medium containing a polymer-polyvinyl alcohol or polyvinylpyrrolidone (PVP)-with concentrations ranging from 0 to 10%. The HA powders were characterized by X-ray diffraction, Fourier transform infrared spectroscopy, atomic emission spectroscopy with inductively coupled plasma, electron paramagnetic resonance, scanning electron microscopy (SEM), and transmission electron microscopy (TEM).

Higher hydrogen fractions in dielectric polymers boost self-healing in electrical capacitors.

Electrical capacitors are omnipresent in modern electronic devices, in which they swiftly release large portions of energy on demand. The capacitors may suffer from arc discharges due to local structural heterogeneities in their components and inappropriate exploitation practices. High energies of the arc discharge are transferred as phonons to the electrode and dielectric film, which burn out locally.

Chemical similarity of dialkyl carbonates and carbon dioxide opens an avenue for novel greenhouse gas scavengers: cheap recycling and low volatility experiments and simulations.

Global warming linked to the industrial emissions of greenhouse gases may be the end of mankind unless it is adequately and timely handled. To prevent irreversible changes to the climate of the Earth, numerous research groups are striving to develop robust CO sorbents. Dialkyl carbonates (DACs) and CO exhibit obvious chemical similarities in their structure and properties.

Extensively amino-functionalized graphene captures carbon dioxide.

The development of robust carbon dioxide (CO) scavengers is a challenging but paramount problem of modern humanity. In the present work, we report a prospective CO sorbent based on amino-functionalized graphene (FG). Amino-FG retains the favorable physicochemical properties of graphene and acquires the capability of chemically fixing CO the carbamic acid formation mechanism.

Ammonium-, phosphonium- and sulfonium-based 2-cyanopyrrolidine ionic liquids for carbon dioxide fixation.

The development of carbon dioxide (CO) scavengers is an acute problem nowadays because of the global warming problem. Many groups around the globe intensively develop new greenhouse gas scavengers. Room-temperature ionic liquids (RTILs) are seen as a proper starting point to synthesize more environmentally friendly and high-performance sorbents.

Enzymes of Polyphosphate Metabolism in Yeast: Properties, Functions, Practical Significance.

Inorganic polyphosphates (polyP) are the linear polymers of orthophosphoric acid varying in the number of phosphate residues linked by the energy-rich phosphoanhydride bonds. PolyP is an essential component in living cells. Knowledge of polyP metabolizing enzymes in eukaryotes is necessary for understanding molecular mechanisms of polyP metabolism in humans and development of new approaches for treating bone and cardiovascular diseases associated with impaired mineral phosphorus metabolism.

Understanding weakly coordinating anions: tetrakis(pentafluorophenyl)borate paired with inorganic and organic cations.

Efficient design of ionic compounds requires a systematic understanding of cation-anion interactions. Weakening of electrostatic attraction is essential to increase the liquid range of the ionic compound and decrease its melting point. Here, we report simulations of the closest-approach cation-anion distances in a variety of ion pairs containing the tetrakis(pentafluorophenyl)borate (TFPB) anion.

Sodium-ion electrolytes based on ionic liquids: a role of cation-anion hydrogen bonding.

Recent success of the sodium-ion batteries fosters an academic interest for their investigation. Room-temperature ionic liquids (RTILs) constitute universal solvents providing non-volatility and non-flammability to electrolytes. In the present work, we consider four families of RTILs as prospective solvents for NaBF4 and NaNO3 with an inorganic salt concentration of 25 and 50 mol%.

Solvation of the morpholinium cation in acetonitrile. Effect of an anion.

Ionic liquids (ILs) constitute a fast growing class of compounds finding multiple applications in science and technology. Morpholinium-based ILs (MBILs) and their mixtures with polar molecular co-solvents are interesting as sustainable electrolyte systems for electrochemistry. We investigate local structures of protic and apropic morpholinium cations in acetonitrile (ACN) using semi-empirical molecular dynamics (MD) simulations.

Polyphosphatase PPN1 of Saccharomyces cerevisiae: switching of exopolyphosphatase and endopolyphosphatase activities.

The polyphosphatase PPN1 of Saccharomyces cerevisiae shows an exopolyphosphatase activity splitting phosphate from chain end and an endopolyphosphatase activity fragmenting high molecular inorganic polyphosphates into shorter polymers. We revealed the compounds switching these activities of PPN1. Phosphate release and fragmentation of high molecular polyphosphate prevailed in the presence of Co2+ and Mg2+, respectively.

Cytoplasmic inorganic polyphosphate participates in the heavy metal tolerance of Cryptococcus humicola.

The basidiomycetous yeast Cryptococcus humicola was shown to be tolerant to manganese, cobalt, nickel, zinc, lanthanum, and cadmium cations at a concentration of 2.5 mmol/L, which is toxic for many yeasts. The basidiomycetous yeast Cryptococcus terreus was sensitive to all these ions and did not grow at the above concentration.

Adaptation of Saccharomyces cerevisiae to toxic manganese concentration triggers changes in inorganic polyphosphates.

The ability of Saccharomyces cerevisiae to adapt to toxic Mn(2+) concentration (4 mM) after an unusually long lag phase has been demonstrated for the first time. The mutants lacking exopolyphosphatase PPX1 did not change the adaptation time, whereas the mutants lacking exopolyphosphatase PPN1 reduced the lag period compared with the wild-type strains. The cell populations of WT and ΔPPN1 in the stationary phase at cultivation with Mn(2+) contained a substantial number of enlarged cells with a giant vacuole.

Expression of apoptosis-related genes in the organ of Corti, modiolus and stria vascularis of newborn rats.

Cell death in the inner ear tissues is an important mechanism leading to hearing impairment. Here, using microarrays and real-time RT-PCR we analyzed expression of selected apoptosis-related genes in rat's inner ear. We determined the gene expression in tissues freshly isolated from neonatal rats (3-5 days old) and compared it to that of explants cultured for 24 h under normoxic or hypoxic conditions.

Recombinant human erythropoietin prevents ischemia-induced apoptosis and necrosis in explant cultures of the rat organ of Corti.

This study was designed to evaluate the effect of recombinant human erythropoietin (rhEPO), insulin-like growth factor-1 (rhIGF-1) and epidermal growth factor (rhEGF) on ischemia-induced hair cell loss in an organotypic cochlea culture. The apical, middle and basal parts of the organs of Corti (newborn rat, postnatal days 3-5) were exposed to ischemia (3.5 h) in glucose-free artificial perilymph (pO2 10-20 mmHg) with or without growth factors.

Menadione reduces rotenone-induced cell death in cerebellar granule neurons.

Oxidative stress has been implicated in neuronal death caused by cerebral ischemia or some neurologic disorders. Chemical hypoxia (term defining the simulation by using respiratory inhibitors) chosen as in vitro ischemic model, was induced in primary cultures of rat cerebellar granule neurons by inhibitors of mitochondrial electron transport such as rotenone or paraquat (complex I), 3-nitropropionic acid (3-NPA, complex II), antimycin A (complex III), or sodium azide (complex IV). All compounds caused neuronal death determined by trypan blue staining and MTT-test.

Expression of hypoxia-inducible factor-1 in the cochlea of newborn rats.

Hypoxia/ischemia is a major pathogenetic factor in the development of hearing loss. An important transcription factor involved in the signaling and adaptation to hypoxia/ischemia is the hypoxia-inducible factor-1 (HIF-1). To study HIF-1 expression we used an in vitro hypoxia model of explant and dissociated cultures of the stria vascularis, the organ of Corti with limbus and the modiolus from the cochlea of 3-5-day-old Wistar rats.

Exopolyphosphatases of the yeast Saccharomyces cerevisiae.

Separate compartments of the yeast cell possess their own exopolyphosphatases differing from each other in their properties and dependence on culture conditions. The low-molecular-mass exopolyphosphatases of the cytosol, cell envelope, and mitochondrial matrix are encoded by the PPX1 gene, while the high-molecular-mass exopolyphosphatase of the cytosol and those of the vacuoles, mitochondrial membranes, and nuclei are presumably encoded by their own genes. Based on recent works, a preliminary classification of the yeast exopolyphosphatases is proposed.