Modern optical astronomy: technology and impact of interferometry

The present `state of the art' and the path to future progress in high spatial resolution imaging interferometry is reviewed. The review begins with a treatment of the fundamentals of stellar optical interferometry, the origin, properties, optical effects of turbulence in the Earth's atmosphere, the passive methods that are applied on a single telescope to overcome atmospheric image degradation such as speckle interferometry, and various other techniques. These topics include differential speckle interferometry, speckle spectroscopy and polarimetry, phase diversity, wavefront shearing interferometry, phase-closure methods, dark speckle imaging, as well as the limitations imposed by the detectors on the performance of speckle imaging. A brief account is given of the technological innovation of adaptive-optics (AO) to compensate such atmospheric effects on the image in real time. A major advancement involves the transition from single-aperture to the dilute-aperture interferometry using multiple telescopes. Therefore, the review deals with recent developments involving ground-based, and space-based optical arrays. Emphasis is placed on the problems specific to delay-lines, beam recombination, polarization, dispersion, fringe-tracking, bootstrapping, coherencing and cophasing, and recovery of the visibility functions. The role of AO in enhancing visibilities is also discussed. The applications of interferometry, such as imaging, astrometry, and nulling are described. The mathematical intricacies of the various `post-detection' image-processing techniques are examined critically. The review concludes with a discussion of the astrophysical importance and the perspectives of interferometry.Comment: 65 pages LaTeX file including 23 figures. Reviews of Modern Physics, 2002, to appear in April issu

Dielectric Behavior of Thin Polymerized Composite Layers Fabricated by Inkjet-Printing

A detailed study of the dielectric behavior of printed capacitors is given, in which the dielectric consists of a thin (<1 µm) ceramic/polymer composite layer with high permittivities of εr 20–69. The used ink contains surface-modified Ba0.6Sr0.4TiO3 (BST), a polymeric crosslinking agent and a thermal initiator, which allows the immediate polymerization of the ink during printing, leading to homogenous layers. To validate the results of the calculated permittivities, different layer thicknesses of the dielectric are printed and the capacitances, as well as the loss factors, are measured. Afterwards, the exact layer thicknesses are determined with cross sectional SEM images of ion-etched samples. Then, the permittivities are calculated with the known effective area of the capacitors. Furthermore, the ink composition is varied to obtain different ceramic/polymer ratios and thus different permittivities. The packing density of all composites is analyzed via SEM to show possible pores and validate the target ratio, respectively. The correlation between the chosen ratio and the measured permittivity is discussed using models from the literature. In addition, the leakage current of some capacitors is measured and discussed. For that, the dielectric was printed on different bottom electrodes as the nature of the electrode was found to be crucial for the performance

Fabrication and Characterization of Fully Inkjet Printed Capacitors Based on Ceramic/Polymer Composite Dielectrics on Flexible Substrates

The preparation of fully inkjet printed capacitors containing ceramic/polymer composites as the dielectric material is presented. Therefore, ceramic/polymer composite inks were developed, which allow a fast one-step fabrication of the composite thick films. Ba0.6Sr0.4TiO3 (BST) is used as the ceramic component and poly(methyl methacrylate) (PMMA) as the polymer. The use of such composites allows printing on flexible substrates. Furthermore, it results in improved values for the permittivity compared to pure polymers. Three composite inks with varying ratio of BST to PMMA were used for the fabrication of composite thick films consisting of 33, 50 and 66 vol% BST, respectively. All inks lead to homogeneous structures with precise transitions between the different layers in the capacitors. Besides the microstructures of the printed thick films, the dielectric properties were characterized by impedance spectroscopy over a frequency range of 100 Hz to 200 kHz. In addition, the influence of a larger ceramic particle size was investigated, to raise permittivity. The printed capacitors exhibited dielectric constants of 20 up to 55 at 1 kHz. Finally, the experimental results were compared to different theoretical models and their suitability for the prediction of εcomposite was assessed

Efficacy of proteolytic enzyme bromelain on health outcomes after third molar surgery. Systematic review and meta-analysis of randomized clinical trials

Bromelain is a cysteine protease isolated from pineapple with a range of biological properties including platelet aggregation inhibition and anti-inflammatory effects. Recent studies have evaluated the clinical implications of bromelain in reducing postoperative inflammatory complications after third molar surgery, but the results are contrasting. This systematic review and meta-analysis evaluated the effects of bromelain on health outcomes in patients submitted to third molar surgery. The study was conducted following the PRISMA statement. Searches were conducted in six electronic databases and Google Scholar from inception to May 2018. The following elements were used to define eligibility criteria: (1) population: patients undergoing third molar surgery; (2) intervention and controls: bromelain vs placebo or no-treatment control group; (3) outcomes: quality of life, postoperative pain, rescue analgesic consumption, facial swelling, and trismus; and (4) study type: randomized clinical trials (RCTs). Treatment effects were defined as weighted (WMD) or standardized mean difference (SMD) and 95%CIs. Six RCTs were included in the meta-analysis. There was large effect size of bromelain on improving physical appearance (SMD -0.77, CI% 95 -1.11 to -0.42), social isolation (SMD -0.97, CI% 95 -1.74 to -0.21), and sleep quality (SMD -1.19, CI% 95 -1.97 to -0.40) during the first postoperative week. Differences in pain intensity were found during the first 24h (SMD -0.49, CI 95% -0.82 to -0.17) and 7 days after surgery (SMD -0.52, CI 95% -0.79 to -0.24). No evidence was found that bromelain was effective in reducing trismus and facial swelling. The currently available evidence suggests that bromelain has a beneficial effect in reducing pain and has a positive impact on patient quality of life after third molar surgery. However, therapeutic advances for the use of bromelain need a high level of evidence and further head-to-head RCTs are needed to inform clinical choices

Estudio de la Microestructura y de las propiedades reológicas de geles de concentrado proteico de sabalo (prochilodus platensis ) en relación a la etapa de lavado con soluciones de H3PO4 y NaHCO

El concentrado de proteínas de pescado (CPP) es el músculo del pescado desmenuzado y exento de huesos, piel,carne oscura y de espinas, que es lavado varias veces con agua y escurrido hasta la proporción de agua original.Aquí se estudió el efecto en la composición físico-química, sobre la microestructura y las propiedades reológicas degeles de CPP utilizando diferentes soluciones de agua de lavado en la obtención de CPP de sábalo (Prochilodusplatensis). Al mismo tiempo se evaluó la extracción de proteínas durante el lavado, y el análisis de las propiedadesreológicas de los geles obtenidos. Los geles de CPP de sábalo obtenidos mediante el método de lavado (0.05%H3PO4, 0.2% NaHCO3 y 0.2% NaCl) presentaron un contenido aceptable de proteínas, el menor contenido demateria grasa, y la textura más aceptable, confirmada por la reología y la microestructura, mostrando mejorasrespecto de los obtenidos por el método convencional. DOI: http://dx.doi.org/10.5377/nexo.v26i1.121

Cell viability and immunostimulating and protective capacities of Bifidobacterium longum 51A are differentially affected by technological variables in fermented milks

Aim:To investigate the cell viability of Bifidobacterium longum 5(1A) in fermented milks and to study its immunostimulating and protective capacity against Salmonella enterica ssp. enterica serovar Typhimurium infection in mice. Methods and Results:  Bifidobacterium longum 5(1A) was added to milk fermented with different yoghurt starter cultures, before or after fermentation, and viability was monitored during storage (5°C, 28 days). Resistance to simulated gastric acid digestion was assessed. Fermented milks were orally administered to mice for 10 days followed by oral infection with Salmonella Typhimurium. The number of IgA+ cells in the small and large intestine was determined before infection. Survival to infection was monitored for 20 days. Bifidobacterium longum 5(1A) lost viability during storage, but the product containing it was effective for the induction of IgA+ cells proliferation in the gut and for the protection of mice against Salm. Typhimurium infection. Conclusions:  Cell viability of Bif. longum 5(1A) in fermented milks along storage did not condition the capacity of the strain to enhance the number of IgA+ cells in the gut and to protect mice against Salmonella infection. Significance and Impact of the Study:  The uncoupling of cell viability and functionality demonstrated that, in certain cases, nonviable cells can also exert positive effects.Fil: Souza, T. C.. Universidade Federal de Minas Gerais. Instituto de Ciências Biológicas; BrasilFil: Zacarías, María Florencia. Universidad Nacional del Litoral. Facultad de Ingeniería Química. Instituto de Lactología Industrial; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Lactología Industrial. Universidad Nacional del Litoral. Facultad de Ingeniería Química. Instituto de Lactología Industrial; ArgentinaFil: Silva, A. M.. Universidade Federal de São João del‐Rei; BrasilFil: Binetti, Ana Griselda. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Lactología Industrial. Universidad Nacional del Litoral. Facultad de Ingeniería Química. Instituto de Lactología Industrial; ArgentinaFil: Reinheimer, Jorge Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Lactología Industrial. Universidad Nacional del Litoral. Facultad de Ingeniería Química. Instituto de Lactología Industrial; ArgentinaFil: Nicoli, J. R.. Universidade Federal de Minas Gerais. Instituto de Ciências Biológicas; BrasilFil: Vinderola, Celso Gabriel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Lactología Industrial. Universidad Nacional del Litoral. Facultad de Ingeniería Química. Instituto de Lactología Industrial; Argentin

Copper (I) SNS Pincer Complexes: Impact of Ligand Design and Solvent Coordination on Conformer Interconversion from Spectroscopic and Computational Studies

The syntheses and detailed characterizations (X-ray crystallography, NMR spectroscopy, cyclic voltammetry, infrared spectroscopy, electrospray mass spectrometry, and elemental analyses) of two new Cu(I) pincer complexes are reported. The pincer ligand coordinates through one nitrogen and two sulfur donor atoms and is based on bis-imidazole or bis-triazole precursors. These tridentate SNS ligands incorporate pyridine and thione-substituted imidazole or triazole functionalities with connecting methylene units that provide flexibility to the ligand backbone and enable high bite-angle binding. Variable temperature 1H NMR analysis of these complexes and of a similar zinc(II) SNS system shows that all are fluxional in solution and permits the determination of ΔGexp‡ and ΔSexp‡. DFT calculations are used to model the fluxionality of these complexes and indicate that a coordinating solvent molecule can promote hemilability of the SNS ligand by lowering the energy barrier involved in the partial rotation of the methylene units

Order-disorder phase transition induced by proton transfer in a co-crystal of 2,4-dichlorobenzoic acid and trimethylamine N-oxide

The crystalline binary adduct between the trimethylamine N-oxide (TMANO) and 2,4-dichlorobenzoic acid (2,4-DCBA) molecules was obtained by slow evaporation from acetonitrile. The obtained molecular complex is formed by a racemic mixture of molecular complexes crystallizing in the orthorhombic space group Pbca. An exhaustive analysis of the temperature dependence of the cell parameters and the behavior of the acidic hydrogen position and carboxilate group were studied by single crystal and powder X-ray diffraction, FT-IR spectroscopy and theoretical calculations. The molecular system was thermally characterized, subsequently demonstrating a order-disorder transition. Finally, the intermolecular interactions were analyzed via Hirshfeld surface analysis