In this Letter, we show 3D steady-state trapping and manipulation of vapor bubbles in liquids employing a low-power continuous-wave laser using the Marangoni effect. Light absorption from photodeposited silver nanoparticles on the distal end of a multi-mode optical fiber is used to produce bubbles of different diameters. The thermal effects produced by either the nanoparticles on the fiber tip or the light bulk absorption modulate the surface tension of the bubble wall and creates both longitudinal and transversal forces just like optical forces, effectively creating a 3D potential well.
View Article and Find Full Text PDFThe formation of superficial nanostructures (SNs) in reduced indium tin oxide (ITO) thin films by H-Glow discharge (GD) at a low reduction temperature (T = 100 °C) was investigated. Sputtered ITO films deposited at low (T = 100 °C) and high (T = 300 °C) temperatures were reduced using this low-temperature process. Scanning electron and atomic force microscopy were applied to study the evolution of the nanostructural features and three stages were identified: emerging/densification, coalescence, and depletion stages.
View Article and Find Full Text PDFIn this work, we present the study of the atomic composition in amorphous SiGe:H films deposited by radio frequency (RF-13.56 MHz) plasma discharge at low deposition temperature. A study and control of Si and Ge atoms termination using H-dilution in SiGe:H alloys deposited by RF plasma discharge was conducted and we made a comparison with low-frequency plasma discharge studies.
View Article and Find Full Text PDFIn this work, we propose poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate) (PEDOT:PSS) material to form a hybrid heterojunction with amorphous silicon-based materials for high charge carrier collection at the frontal interface of solar cells. The nanostructural characteristics of PEDOT:PSS layers were modified using post-treatment techniques via isopropyl alcohol (IPA). Atomic force microscopy (AFM), Fourier-transform infrared (FTIR), and Raman spectroscopy demonstrated conformational changes and nanostructural reorganization in the surface of the polymer in order to tailor hybrid interface to be used in the heterojunctions of inorganic solar cells.
View Article and Find Full Text PDFThin-film hybrid organic-inorganic photovoltaic structures based on hydrogenated silicon (Si:H), poly(3,4ethylenedioxythiophene):poly(4-styrenesulfonate) (PEDOT:PSS) polymer Al-doped ZnO (AZO) films deposited on different types of flexible substrates have been fabricated and investigated. The compatibility of the polymer and inorganic materials regimes and deposition techniques used for device fabrication has been demonstrated on flexible substrates. Morphological characteristics of transparent Al-doped ZnO (AZO) films deposited on substrates have been measured by atomic force microscopy.
View Article and Find Full Text PDFWe present a device for measuring displacement based on the Talbot and the nonsteady photo-electromotive force effects. The proposed device does not require any numerical signal processing since its output signal is, in appropriate regions, linearly related to the measured displacement. The proposed system requires an illuminating field with a sinusoidal amplitude distribution and low fringe visibility.
View Article and Find Full Text PDFNon-steady-state photoelectromotive force effect in the presence of periodical and linear phase shift was investigated both theoretically and experimentally. It was shown that superposition of oscillating and linear movements of the interference pattern leads to the appearance of the sharp peak in the frequency dependence of the photoelectromotive force output current when the frequency of periodical modulation matches the frequency of the linear phase shift. We demonstrated experimentally that this effect can be used for determination of a Doppler frequency shift between signal and reference beam.
View Article and Find Full Text PDFMany apoptotic signals are known to induce release to cytosol of cytochrome c, a small mitochondrial protein with positively charged amino acid residues dominating over negatively charged ones. On the other hand, in this group, it was shown that prothymosin alpha (PT), a small nuclear protein where 53 of 109 amino acid residues are negatively charged, is truncated to form a protein of 99 amino acid residues which accumulates in cytosol during apoptosis [FEBS Lett. 467 (2000) 150].
View Article and Find Full Text PDFEarlier we reported that some thyroid and steroid hormones and also 6-ketocholestanol used in micromolar concentrations modulated the effects of protonophoric uncouplers on isolated mitochondria (Starkov et al. (1997) Biochim. Biophys.
View Article and Find Full Text PDFBiochim Biophys Acta
January 1997
Male sex hormones [dihydrotestosterone (DTS), and testosterone] and progesterone, when added to the isolated rat liver mitochondria before or after some protonophores, lower the respiration rate and increase the delta psi level, i.e., reverse the protonophore-induced uncoupling.
View Article and Find Full Text PDFThe effect of 6-ketocholestanol (kCh) on various natural and reconstituted membrane systems has been studied. 6-ketocholestanol (5 alpha-Cholestan-3 beta-ol-6-one), a compound increasing the membrane dipole potential, completely prevents or reverses the uncoupling action of low concentrations of the most potent artificial protonophore SF6847. This effect can be shown in the rat liver and heart muscle mitochondria, in the intact lymphocytes, in the Rhodobacter sphaeroides chromatophores, and in proteoliposomes with the heart muscle or Rh.
View Article and Find Full Text PDFA convenient procedure is proposed for extracting mitochondrial proteolipids using a single phase mixture chloroform-methanol-water (1:2:0.8 v/v) with subsequent separation of the phases. The proteolipids were concentrated at the interface between the phases and thus purified from the bulk of the phospholipids.
View Article and Find Full Text PDFA sensitive colorimetric method for the assay of inorganic pyrophosphate with excess of orthophosphate is described. The principle of this method lies in the formation of phosphomolybdate and PPi-molybdate complexes with subsequent extraction of the phosphomolybdate complex by organic solvents and reduction of the PPi-molybdate complex by dithiothreitol and Eikonogen. The sensitivity of the method was from 5 to 120 nmol of PPi in a 2.
View Article and Find Full Text PDFThe effect of temperature on the hydrolase activity of mitochondrial pyrophosphatases, i.e. soluble (PPase I) and membrane (PPase II), has been studied.
View Article and Find Full Text PDFUkr Biokhim Zh (1978)
September 1984
It was demonstrated previously that mitochondria of higher and lower eukaryotes can synthesize, in the course of oxidative phosphorylation, not only ATP but also inorganic pyrophosphate (PPi). Two PPases were isolated from bovine heart mitochondria (soluble--PPase I and membrane--PPase II). Coupling PPase II, in contrast to PPase I, contains phosphatidyl choline, but PPase I is lipidized readily in the presence of different phospholipids.
View Article and Find Full Text PDFThe effects of lipids on the activity of soluble and membrane-bound pyrophosphatase from beef heart mitochondria were studied. An addition of total mitochondrial lipid, phosphatidyl choline, phosphatidyl ethanolamine or cardiolipin resulted in stimulation of the enzymatic activity and an increase in thermal stability of the soluble enzyme. The maximal activating effect was exerted by the total mitochondrial lipid and phosphatidyl choline.
View Article and Find Full Text PDFThe effect of respiration rate on the content and accumulation of ATP and PPi in rat liver mitochondria was studied. It was found that the syntheses of ATP and PPi occur at different respiration rates. It was assumed that the respiration rate can determined the formation of ATP or PPi via oxidative phosphorylation.
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