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Contamination-free Ag nanoparticles were produced by nanosecond pulsed laser ablation (10 Hz repetition rate, 15 ns pulse duration) of a solid target immersed in double distilled water. The size distribution observed of the NPs is wider compared to those obtained by other preparation methods, mainly chemical. To modify it and make the NPs more appropriate for biological application, the fabricated suspensions were irradiated by an unfocused laser beam. The fundamental wavelength (λ = 1064 nm) of a Nd:YAG laser system was used for Ag NPs preparation. It lies outside their surface plasmon absorption band and was chosen to avoid self-absorption during ablation by already formed NPs. Excluding a possible absorption in the preparation stage provides a better control of the irradiation influence. The following irradiation of the suspension obtained was performed by the third (λTHG = 355 nm) harmonic of the laser system, which was chosen due to its positioning within the corresponding surface plasmon absorption band. The changes of the NPs characteristics caused by different laser fluence and duration of irradiation were traced by transmission electron microscopy (TEM) and confirmed by optical transmission measurements in the near UV and the visible region. A considerable narrowing (by about of a factor of three) of the surface plasmon extinction band was achieved, which is evidence of narrowing of the particles size distribution and approach of their shape to the ideal spherical.

The optical properties of gold nanoparticle clusters are presented from the point of view of their applications in biophotonics, where the absorption and scattering spectra are crucial. Generalised multiparticle Mie theory and finite difference time domain (FDTD) technique are used for theoretical description of the far- and nearfield optical properties of two dimensional nanoparticle ensembles. The system under consideration consists of spherical gold nanoparticles from 20 to 200 nm in diameter, forming 2D clusters in water. The properties of the far-field absorption and scattering spectra as a function of the cluster size, particle dimensions, and interparticle distance are investigated for ordered hexagonal structure of the particle arrays. It is found that the absorption efficiency can be shifted to the IR spectral range by increasing array size and decreasing interparticle distance. The increase in the array size also results in enhancement of the scattering efficiency while the absorption is reduced. The near-field intensity distribution is inhomogeneous over the array, as formation of zones with intensity enhancement of about two orders of magnitude is observed in specific areas. The optical properties of an ensemble whose configuration is reproduced from real experiments of gold nanoparticle deposition onto cancer cells are also presented. The results obtained can be used in designing of nanoparticle arrays with applications in biophotonics, bioimaging and photothermal therapy.

Preparation of noble metal nanoparticle (NPs) colloids using pulsed laser ablation in water has an inherent advantage compared to the different chemical methods used, especially when biological applications of the colloids are considered. The fabrication method is simple and the NPs prepared in this way are contamination free. The method of laser ablation of a solid target in water is applied in the present work in order to obtain gold and silver NP colloids. The experiment was preformed by using the fundamental wavelength (1064 nm) of a Nd:YAG laser system. The target immersed in double distilled water was irradiated for 20 min by laser pulses with duration of 15 ns and repetition rate of 10 Hz. The sedimentation and aggregation of NPs in the colloids, stored at constant temperature, as a function of the time after preparation were investigated. The analyses are based on optical transmission spectroscopy in UV and vis regions. The change of the plasmon resonance wavelength as a function of time was studied. Zeta potential measurement was also utilized to measure the charge of the NPs in the colloids. The size distribution of the NPs and its change in time was determined by transmission electron microscopy (TEM). On the basis of the results obtained, the optimal conditions of post fabrication manipulation with gold and silver colloids are defined in view of producing stable NPs with a narrow size distribution.

Hemocyanins are blue copper containing respiratory proteins residing in the hemolymph of many molluscs and arthropods. They can have different molecular masses and quaternary structures. Moreover, several molluscan hemocyanins are isolated with one, two or three isoforms occurring as decameric, didecameric, multidecameric or tubule aggregates. We could recently isolate three different hemocyanin isopolypeptides from the hemolymph of the garden snail Helix lucorum (HlH). These three structural subunits were named αD-HlH, αN-HlH and β-HlH. We have cloned and sequenced their cDNA which is the first result ever reported for three isoforms of a molluscan hemocyanin. Whereas the complete gene sequence of αD-HlH and β-HlH was obtained, including the 5′ and 3′ UTR, 180 bp of the 5′ end and around 900 bp at the 3′ end are missing for the third subunit. The subunits αD-HlH and β-HlH comprise a signal sequence of 19 amino acids plus a polypeptide of 3409 and 3414 amino acids, respectively. We could determine 3031 residues of the αN-HLH subunit. Sequence comparison with other molluscan hemocyanins shows that αD-HlH is more related to Aplysia californicum hemocyanin than to each of its own isopolypeptides. The structural subunits comprise 8 different functional units (FUs: a, b, c, d, e, f, g, h) and each functional unit possesses a highly conserved copper-A and copper-B site for reversible oxygen binding. Potential N-glycosylation sites are present in all three structural subunits. We confirmed that all three different isoforms are effectively produced and secreted in the hemolymph of H. lucorum by analyzing a tryptic digest of the purified native hemocyanin by MALDI-TOF and LC–FTICR mass spectrometry.

Pulsed laser deposition technique was used to fabricate successfully nanostructured optical waveguide films of TiO2 and WO3 − x for gas-sensing applications. High-quality mode spectra, consisting of well-defined bright mode lines were observed in the samples with smooth surface. Films' structural, morphological and optical properties as well as the chemical composition were investigated by using x-ray diffraction, scanning electron and atomic force microscopy, UV–VIS–NIR, m-line and x-ray photoelectron spectroscopy, respectively. Gas sensitivity was investigated at room temperature using m-line spectroscopy technique on basis of reversible variations of the refractive index of the samples under gas exposure. Testing scheme recording the bright m-line shift as optical response was proposed.

In this work, erbium, and erbium and ytterbium co-doped YVO 4 waveguiding thin films were deposited on amorphous SiO 2 substrates by pulsed laser deposition (PLD) and ultraviolet-assisted pulsed laser deposition (UVPLD). The influence of the deposition technique on the structure, morphology, and optical properties of the films was investigated. At lower dopant concentrations the films prepared by UVPLD show better crystallinity and optical properties. All the samples show preferred orientation of the (001) zone axes parallel to the substrate surface. The polycrystalline samples show difference in the refractive indexes ∆ n (∆ n = n TE − n TM ) for the TE and TM polarizations.

The evolution of the crystal, the microstructural and the optical properties of pulsed-laser deposited TiO2 films, investigated by X-ray diffraction, atomic force microscopy, scanning electron microscopy, optical transmittance and m-line spectroscopy measurements are reported. The samples were grown on (0 0 1) SiO2 substrates at temperatures from 250 to 600 °C and oxygen pressures from 1 to 15 Pa. Crystalline films consisting of single anatase or anatase and rutile phases, were obtained at temperatures higher than 400 °C. A tendency toward columnar-like growth morphology was observed in the samples. Strong dependence of the optical properties on the surface roughness and the microstructure was determined. All films revealed single-mode waveguiding and optically anisotropic properties.

Erbium, and erbium and ytterbium co-doped YVO4 waveguiding films were deposited on MgO/Si substrates by PLD. The samples were post-annealed at two different temperatures in air atmosphere. The influence on the crystalline structure and waveguiding properties of the films at these annealing temperatures for two dopant concentrations was investigated. Layers annealed up to 900 °C are polycrystalline. The dominant fraction of YVO4 crystallites exhibited preferred orientation of the (0 0 1) zone axes parallel to the substrate surface. The polycrystalline samples show difference in the refractive indexes Δn (Δn = nTE − nTM) for TE and TM polarizations.

Molluscan hemocyanins (Hcs) have recently particular interest due to their significant immunostimulatory properties. This is mainly related to their high carbohydrate content and highly specific monosaccharide composition. Our study revealed a highly heterogeneous mixture of different glycans isolation from structural subunit RvH2 of Rapana venosa hemocyanin at least 28 different compositions of Hex0-9 HexNAc2-4 Hex0-3 Pent0-3 Fuc0-3 and deoxyhexose and pentose residues. A novel type of N-glycan, with an internal Fuc connecting one GalNAc(β1–2) and one hexuronic acid, was detected in RvH2 as was previously found in subunit RvH1.We compared investigation on antiviral effects of several molluscas hemocyanins (keyhole limpet hemocyanin, Rapana venosa hemocyanin and Helix vulgaris hemocyanin) and the arthropod Carcinus aestuarii hemocanin. For the first time, we demonstrate here the inhibitory effect of one glycosylated functional unit of molluscan hemocyanin against viruses. The FU RvH-1 of Rapana ve...

In this work the optical and the gas sensing properties of thick TiO 2 waveguide films, produced by pulsed laser deposition, were investigated by m -line spectroscopy. The films were deposited on (0 0 1) SiO 2 substrates at temperature of 100 °C. The thickness of the films was measured to be in the range from 650 to 1900 nm and the roughness increases from 5 to 14.6 nm. High quality mode spectra, consisted of thin and bright TE and TM modes, were observed in the films with thickness up to 1200 nm. All the films revealed anisotropic optical properties. Gas sensitivity of the films to CO 2 was examined at room temperature on the basis of the variations of the refractive index. CO 2 concentration of 3 × 10 4 ppm was detected, which corresponds to a refractive index variation of about 1 × 10 −4 . The crystal structure and the optical transmittance of the films were also presented and discussed.

The purpose of the present investigation is the fabrication of undoped and palladium doped indium tin oxide films by pulsed laser deposition and the analyses of their optical, waveguide and structural properties in view of optical sensor applications. The films are deposited at oxygen pressure from 5 to 20 Pa and substrate temperature between 200 and 450 °C. Palladium is used as a dopant since it is critical in improving the sensor's properties. The X-ray diffraction spectra show that all films are polycrystalline with preferential [1 1 1] orientation. The optical transmittance measured in the visible region has maximum values of 85–90% for films grown at oxygen pressure 15 Pa independently of the substrate temperature used. SEM, AFM and optical and investigations revealed that indium tin oxide films with 1 wt.% Pd have higher transmittance and better surface morphology than those with 3 wt.% Pd concentration. ITO films with minimum propagation losses of 2 dB cm −1 were deposited at substrate temperature 200 °C and oxygen pressure 5 Pa, but doped ITO films with minimum propagation losses were obtained at 400 °C and 15 Pa.

In this work, thin YVO 4 films were deposited on amorphous SiO 2 substrates by pulsed laser deposition (PLD). Ceramic targets of pure and doped (Er and Er, Yb) YVO 4 were prepared and used for ablation. The influence of the substrate temperature and oxygen pressure applied during the depositions was investigated. Crystalline films were obtained at temperatures higher than 500 °C. The films with the best crystallinity were obtained at 5 Pa oxygen pressure and 700 °C substrate temperature. All the films are transparent in the visible and near infrared region of spectra. The crystalline samples show difference in the refractive indexes Δ n (Δ n = n TE − n TM ) for the TE and TM polarizations. It was evaluated to be about 0.08.

Thin Er3+, Yb3+ co-doped Y2O3 films were grown on (1 0 0) YAG substrates by pulsed laser deposition. Ceramic targets having different active ion concentration were used for ablation. The influence of the rare-earth content and oxygen pressure applied during the deposition on the structural, morphological and optical properties of the films were investigated. The films deposited at the lower pressure, 1 Pa, and at 1/10 Er to Yb doping ratio are highly textured along the (1 1 1) direction of the Y2O3 cubic phase. In addition to the crystalline structure, these films possess smoother surface compared to those prepared at the higher pressure, 10 Pa. All other films are polycrystalline, consisting of cubic and monoclinic phases of Y2O3. The rougher surface of the films produced at the higher-pressure leads to higher scattering losses and different behavior of the reflectivity spectra. Optical anisotropy in the films of less than 0.004 was measured regardless of the monoclinic structure obtained. Waveguide losses of about 1 dB/cm at 633 nm were obtained for the films produced at the lower oxygen pressure.

5th European-Materials-Research-Society Symposium on Laser Material Interactions for Micro- and Nano- Applications, Strasbourg, FRANCE, MAY 27-31, 2013; International audience; The experimental conditions were investigated enabling one to fabricate Au nanowire networks by pulsed laser ablation in water. The study revealed that it is possible to produce alternatively nanoparticles (or aggregates) or nanowire networks at certain wavelengths depending on the laser fluence. An Au disc immersed in double-distilled water was used as a target. The second (lambda(SHG) = 532 nm) and the third lambda(THG) = 355 nm) harmonics of a Nd:YAG laser system were utilized to produce different Au colloids. The values of the laser fluence for both wavelengths under the experimental conditions chosen were varied from several J/cm(2) to tens of J/cm(2). The optical extinction spectra of the colloids in the UV/vis region were obtained to evaluate the structure of the dispersed Au phase. Transmission electron microscopy (TEM) was applied to visualize the size and morphology of the colloidal particles. Their structure and phase composition were studied by high-resolution transmission electron microscopy (HRTEM) and selected area electron diffraction (SAED) and used to make an assumption on how they had been formed. (C) 2014 Elsevier B.V. All rights reserved.

In paper is presented a research complex which will recreate as closely as possible the diversity of the real working environment with appropriate incentives and will register the necessary examination of physical, physiological signals and parameters. Apparatus complex will simulate close to real work situations, will include tests necessary to assess the psychological status of the research subject. Further ahead in the complex algorithm will monitor the overall conduct of the experiment will record and process information from all physiological channels: electro miograma, electrocardiogram, blood pressure, pulse wave, respiration rate, galvanic skin response. The operator will receive visual and auditory information from the computer complex and will communicate with him through a special keyboard, standard optical mouse, track ball, stick and pedal controls. It is proposed methodology for conducting comprehensive studies of operator in extreme conditions. The developed complex will contribute to enhancing the skills of operators of mission-critical systems - pilots, pilots, operators of unmanned aerial vehicles, astronauts, heads of air traffic, nuclear operators and drivers of public transport.

Molluscan hemocyanins are very large biological macromolecules and they act as oxygen-transporting glycoproteins. Most of them are glycoproteins with molecular mass around 9000 kDa. The oligosaccharide structures of the structural subunit RvH2 of Rapana venosa hemocyanin (RvH) were studied by sequence analysis of glycans using MALDI-TOF-MS and tandem mass spectrometry on a Q-Trap mass spectrometer after enzymatical liberation of the N-glycans from the polypeptides. Our study revealed a highly heterogeneous mixture of glycans of the compositions Hex(0-9) HexNAc(2-4) Hex(0-3) Pent(0-3) Fuc(0-3). A novel type of N-glycan, with an internal fucose residue connecting one GalNAc(β1-2) and one hexuronic acid, was detected, as also occurs in subunit RvH1. A glycan with the same structure but with two deoxyhexose residues was observed as a doubly charged ion. Antiviral effects of the native molecules of RvH and also of Helix lucorum hemocyanin (HlH), of their structural subunits, and of the glycosylated functional unit RvH2-e and the non-glycosylated unit RvH2-c on HSV virus type 1 were investigated. Only glycosylated FU RvH2-e exhibits this antiviral activity. The carbohydrate chains of the FU are likely to interact with specific regions of glycoproteins of HSV, through van der Waals interactions in general or with certain amino acid residues in particular. Several clusters of these residues can be identified on the surface of RvH2-e.

Hemocyanins are giant extracellular oxygen carriers in the hemolymph of many molluscs and arthropods with different quaternary structure. They are represented in the hemolymph of molluscs with one, two or three isoforms, as decameric, didecameric, multidecameric and tubules aggregates. We describe here the structure of the hemocyanin Helix lucorum (HlH), species in the series of molluscan hemocyanins. In contrast with other molluscan hemocyanins, three different hemocyanin isopolypeptides were isolated from the hemolymph of the garden snail H. lucorum, named as beta-HlH, alpha(D)-HlH and alpha(N)-HlH. Their molecular masses were determined by size exclusion chromatography to be 1068 kDa (beta-HlH) and 1079 kDa (alpha(D)-HlH, and alpha(N)-HlH). Native HlH exhibits a predominant didecameric structure as revealed by electron microscopy and additionally few tridecamers are shown in the electron micrographs of HlH resulting from the association of a further decamer with one didecamer. The three isoforms are represented mainly as homogeneous didecamers, but they have different behaviour after dissociation and reassociation in the pH-stabilizing buffer, containing 20 mM CaCl(2). All isoforms were reassociated into didecamers and tubules with different length, but in contrast to alpha(D)-HlH isoform, longer tubules were observed in beta-HlH. Moreover the structure of beta-HlH was analysed after limited proteolysis with trypsin followed by FPLC and HPLC separation of the cleavage products. Eight different functional units were identified by their N-terminal sequences and molecular masses. The protein characteristics, including UV absorption at 340 nm, fluorescence and CD spectra of the native molecule and its units confirmed the structure of multimer protein complexes.

We report on the results of ultraviolet (UV)-assisted annealing of thin Y203 films produced by pulsed laser deposition.An excimer XeC1 laser was used for ablation of Y203 ceramic target. The films were grown on (001) Si02 substrates at500 °C and oxygen pressure of 0.05 mbar. The effect of UV—assisted laser annealing on the structure, morphology, andoptical properties was investigated. The UV-assisted annealing was performed by the same laser. The beam was directedparallel or toward the surface of the as—deposited films. The influence of the ambient gas (02 or N20) is explored. Theambient atmosphere has an influence on the preferential (cubic or monoclinic) phase of growth while it has no significanteffect on the surface morphology. The absorption coefficient in the VIS range has a lower value for the films annealedwith laser directed parallel to the surface independently on the gas environment. Annealing of the films with laser beamdirected at the film surface slightly increases the refractive index, independently of the gas ambient.Keywords: UV-assisted annealing, Y203, PLD

Thin TiO 2 films were grown on (001) SiO 2 substrates using excimer KrF laser ablation of ceramic targets. The influence of deposition temperatures at fixed oxygen pressure of 10 Pa on the crystal and optical properties of the films was investigated. Structural characterisation by X-ray diffraction and Raman spectroscopy shows preferential crystallization of the anatase TiO 2 films were obtained at high temperatures of 500 and 600 °C, respectively. Optical transmission as high as 92% in the visible spectral region was measured for films grown at temperatures higher than 400 °C. The refractive index and the thickness of the films measured by m-line spectroscopy shows the highest values of 2/41 and 250 nm, respectively, at deposition temperature of 600 °C.

Highly textured pure and Al doped ZnO thin films have been produced by pulsed laser deposition for optical gas sensor application. The influence of the processing parameters such as substrate temperature and oxygen pressure applied during depositions, and dopant concentration on the structural, morphological, and optical properties of the films were investigated. All deposited films are textured along the (002) direction. The substrate temperature and the oxygen pressure have stronger influence on the film crystallinity compared to the presence of the dopants. The grain size of the films prepared from 2 wt% Al2O3 doped ZnO target is approximately the same as the one produced from pure ZnO tagret. The increase in the dopant concentration into the ZnO target (to 5 wt% Al2O3) leads to an increase of the in-plane grain size of the as-deposited films which is well known to increase the gas sensitivity. At the same time, the use of doped targets increase the droplets on the film surface which deteriorates the optical detection of the gas sensing effect. The increase of the dopant concentration reduces the film transmission in the visible range and the transmission cut-off edge is shifted to the shorter wavelengths. The films deposited from 2 wt% Al2O3 doped ZnO target at oxygen pressure of 0.05 mbar and 300°C substrate temperature have good mode properties which makes them good candidates for optical sensors.

With the aim of preparing copolymers of trioxane with acenaphthylene, the polymerization of a mixture of both monomers was carried out in the presence of boron trifluoridediethyl etherate in benzene and tetrachloromethane and in melt. In most monomer ratios, irrespective of the degree of conversion, products were obtained, which were composed of two fractions: one fusible and soluble in benzene and tetrachloromethane, containing almost pure polyacenaphthylene, and another infusible and insoluble in organic solvents with a high polyformaldehyde content. On polymerization of the monomer mixture under the action of γ-rays only insoluble and infusible products were formed. On the basis of the experimental results and the literature data an attempt is made to explain the formation of insoluble products and an opinion is expressed, that no copolymerization of the monomers is likely to take place under the experimental conditions employed. Um Copolymere des Trioxans mit Acenaphthylen zu erhalten wurde ein Gemisch beider Monomerer in Benzol oder Tetrachlormethan sowie in Schmelze mittels Bortrifluoriddiathylatherat polymerisiert. Bei den meisten Monomerenverhaltnissen wurden unabhangig vom Umsatz Produkte erhalten, die aus zwei Fraktionen bestehen. Die eine Fraktion ist schmelzbar, in Benzol loslich und enthalt fast nur Polyacenaphthylen, die andere unschmelzbar, unloslich in organischen Losungsmitteln und mit hohem Polyformaldehydgehalt. Bei der Polymerisation eines Gemisches aus beiden Monomeren unter der Wirkung von γ-Strahlen wurden nur unlosliche Produkte erhalten. Auf Grund der Versuchsergebnisse und der Literaturangaben wurde die Bildung der unloslichen Produkte zu erklaren versucht. Nach Ansicht der Autoren durfte unter den gegebenen experimentellen Bedingungen kaum eine Copolymerisation der beiden Monomeren stattfinden.