Analysis of a scheme for de-magnified Talbot lithography Analysis of a scheme for de-magnified Talbot lithography

Formation of large-area GaN nanostructures with controlled geometry and morphology using top-down fabrication scheme J. Vac. Sci. Technol. B 30, 052202 (2012) Resist-substrate interface tailoring for generating high-density arrays of The authors describe a photolithographic scheme based on the replication of a periodic transparent mask in a photoresist utilizing the coherent self-imaging Talbot effect. A periodic two-dimensional diffractive structure (or Talbot mask) composed of unit tiles distributed in a square matrix was illuminated by a coherent extreme ultraviolet (EUV) beam from a table top EUV laser. The illumination beam was reflected in a spherical mirror and the Talbot mask was placed in the path of the convergent beam. At designed locations determined by the Talbot distance, reduced replicas of the mask were obtained and used to print the slightly de-magnified copies of the mask on the surface of a photoresist. Experimental results showing the de-magnification effect are in good agreement with the diffraction theory. The limits of the technique are discussed

Design and Analysis of a Mutant Form of the Ice-binding Protein From\u3cem\u3e Choristoneura Fumiferana\u3c/em\u3e

Ice-binding proteins are expressed in the cells of some cold adapted organisms, helping them to survive at extremely low temperatures. One of the problems in studying such proteins is the difficulty of their isolation and purification. For example, eight cysteine residues in the cfAF (antifreeze protein from the eastern spruce budworm Choristoneura fumiferana) form intermolecular bridges during the overexpression of this protein. This impedes the process of the protein purification dramatically. To overcome this issue, in this work, we designed a mutant form of the ice-binding protein cfAFP, which is much easier to isolate that the wild-type protein. The mutant form named mIBP83 did not lose the ability to bind to ice surface. Besides, observation of the processes of freezing and melting of ice in the presence of mIBP83 showed that this protein affects the process of ice melting, increasing its melting temperature, and does not decrease the water freezing temperature

Superoxide-producing lipoprotein fraction from Stevia leaves: definition of specific activity

Abstract Background Stevia rebaudiana Bertoni has various pharmacological actions, which includes antidiabetic, antioxidant, anti-inflammatory activities. The superoxide and consequently NADPH oxidase (Nox) are relevant targets involved in biological effects of Stevia. The presence of NADPH-containing superoxide-producing lipoprotein (suprol) in Stevia leaves has not yet been tested. The mechanism of producing superoxide radicals (O2 −) by suprol was determined in vitro, which is associated with the electron transfer from NADPH in the composition of suprol by traces of transition metal ions (Fe3+ or Cu2+) to molecular oxygen, turning it into O2 −. It is expected that the therapeutic efficacy of Stevia leaves is caused by specific activity of superoxide-producing lipoprotein fraction. Methods For the first time, from the dry leaves of Stevia the NADPH-containing superoxide-producing lipoprotein was isolated and purified. The specific content of suprol (milligrams in 1 g of Stevia leaves- mg/g) was determined after desalination of suprol and lyophilization. Results According to the method provided, the specific content of the isolated suprol from Stevia’s leaves was up to 4.5 ± 0.2 mg / g (yields up to 68.5 ± 4.7%, p < 0.05, n = 6). Nox forms a stable complex with suprol. The optical absorption spectrum of the Nox-suprol complex represents the overlapping suprol and Nox spectra, with a certain background increase and characteristic features of optical absorption for Nox. Due to O2 − producing capacity suprol-Nox complex discolors KMnO4 solutions, Coomassie brilliant blue, restores nitrotetrazolium blue to formazan and oxidizes epinephrine to adrenochrome. The oxidation activity of adrenaline is 50.3 ± 5.1 U / mg / ml (p < 0.05, n = 6). Conclusion Superoxide-producing lipoprotein fraction-Nox complex from Stevia leaves (membranes) can modulate redox regulated signaling pathways and may play a positive role in type-2 diabetes by means of adrenaline oxidation mechanism

Effects of stevia on synaptic plasticity and NADPH oxidase level of CNS in conditions of metabolic disorders caused by fructose

Abstract Background Excess dietary fructose intake associated with metabolic syndrome and insulin resistance and increased risk of developing type 2 diabetes. Previous animal studies have reported that diabetic animals have significantly impaired behavioural and cognitive functions, pathological synaptic function and impaired expression of glutamate receptors. Correction of the antioxidant status of laboratory rodents largely prevents the development of fructose-induced plurimetabolic changes in the nervous system. We suggest a novel concept of efficiency of Stevia leaves for treatment of central diabetic neuropathy. Methods By in vivo extracellular studies induced spike activity of hippocampal neurons during high frequency stimulation of entorhinal cortex, as well as neurons of basolateral amygdala to high-frequency stimulation of the hippocampus effects of Stevia rebaudiana Bertoni plant evaluated in synaptic activity in the brain of fructose-enriched diet rats. In the conditions of metabolic disorders caused by fructose, antioxidant activity of Stevia rebaudiana was assessed by measuring the NOX activity of the hippocampus, amygdala and spinal cord. Results In this study, the characteristic features of the metabolic effects of dietary fructose on synaptic plasticity in hippocampal neurons and basolateral amygdala and the state of the NADPH oxidase (NOX) oxidative system of these brain formations are revealed, as well as the prospects for development of multitarget and polyfunctional phytopreparations (with adaptogenic, antioxidant, antidiabetic, nootropic activity) from native raw material of Stevia rebaudiana. Stevia modulates degree of expressiveness of potentiation/depression (approaches but fails to achieve the norm) by shifting the percentage balance in favor of depressor type of responses during high-frequency stimulation, indicating its adaptogenic role in plasticity of neural networks. Under the action of fructose an increase (3–5 times) in specific quantity of total fraction of NOX isoforms isolated from the central nervous system tissue (amygdala, hippocampus, spinal cord) was revealed. Stevia exhibits an antistress, membrane-stabilizing role reducing the level of total fractions of NOX isoforms from central nervous system tissues and regulates NADPH-dependent O2 − −producing activity. Conclusion Generally, in condition of metabolic disorders caused by intensive consumption of dietary fructose Stevia leaves contributes to the control of neuronal synaptic plasticity possibly influencing the conjugated NOX-specific targets