Dynamic phase evaluation in sparse-sampled temporal speckle pattern sequence

The rapid progress of modern manufacturing technology has posed stringent requirements for inspecting techniques for vibration characterization and dynamic testing. Because of its simplicity, accuracy, and whole-field character, speckle interferometry has served as one of the major techniques for dynamic measurement, where normally a dense-sampled temporal speckle sequence is captured for phase retrieval using Fourier or wavelet transforms. In this Letter, a method is proposed for phase evaluation of sparse-sampled speckle patterns when the sampling rate is lower than two points per temporal cycle. Dynamic experiments using a high-speed camera demonstrated the effectiveness of the proposed method for complicated wrapped phase retrieval in electronic/digital speckle pattern interferometry.     

Solvent Effects on Tautomeric and Microscopic Protonation Constants of Glycine in Different Aqueous Solutions of Methanol and Ethanol

The acid-base equilibria of glycine have been studied in different aqueous solutions of methanol and ethanol (0?C45?% v/v) using a potentiometric method. In this study, the macro and micro protonation constants of the amino acid and its tautomeric constant have been determined at 25?°C and constant ionic strength (0.1 mol?dm^?3 NaClO₄). The protonation and the tautomeric constants of glycine in different binary mixtures were analyzed in terms of the Kamlet, Abboud and Taft (KAT) parameters. Single-parameter correlations of the constants versus ?? (hydrogen-bond donor acidity), ?? (hydrogen-bond acceptor basicity) and ?? ^? (dipolarity/polarizability) are poor in all solutions. Multi-parameter correlations show better results, but dual-parameter correlations represent significant improvements with regard to the single- and multi-parameter models. Linear correlation is observed when the experimental protonation constant values are plotted versus the calculated ones when the KAT parameters are considered. Finally, the results are discussed in terms of the effect of the solvent on protonation and tautomeric constants.     

Some physical properties concerning the thermal conductivity data of BaO-containing silicate glasses in relation to structure

The thermal conductivity, density, refractive index and viscosity of glasses with base composition (wt%): Na₂O, 20; CaO, 15; SiO₂ 65, in which CaO is partially replaced by BaO, have been investigated.Both the thermal conductivity and the viscosity—temperature values progressively decreased by introducing BaO to replace CaO in the glasses. Meanwhile, this replacement caused an increase in other properties, i.e., density and refractive index. The experimental measurements and calculated values of either thermal conductivity or viscosity agree fairly well. The observed effects were correlated to factors such as polarization, field strength and ionic radii of the incorporated divalent cations, and their effect on the geometrical arrangement of the building units of the glassy network.     

All linear optical quantum memory based on quantum error correction

When photons are sent through a fiber as part of a quantum communication protocol, the error that is most difficult to correct is photon loss. Here we propose and analyze a two-to-four qubit encoding scheme, which can recover the loss of one qubit in the transmission. This device acts as a repeater, when it is placed in series to cover a distance larger than the attenuation length of the fiber, and it acts as an optical quantum memory, when it is inserted in a fiber loop. We call this dual-purpose device a "quantum transponder."     

Edge-clique graphs

The edge-clique graphK(G) of a graphG is that graph whose vertices correspond to the edges ofG and where two vertices ofK(G) are adjacent whenever the corresponding edges ofG belong to a common clique. It is shown that every edge-clique graph is a clique graph, and that ifG is either an interval graph or a line graph, then so too isK(G). An algorithm is provided for determining whether a graph is an edge-clique graph. A new graph called the STP graph is introduced and a relationship involving this graph, the edge-clique graph, and the line graph is presented. The STP graphs are also characterized.Research supported in part by Office of Naval Research Contract N00014-88-K-0018.Research supported in part by Office of Naval Research Contract N00014-88-K-0163.     

Valproic Acid Promotes Apoptosis and Cisplatin Sensitivity Through Downregulation of H19 Noncoding RNA in Ovarian A2780 Cells

Cisplatin resistance is one of the main limitations in the treatment of ovarian cancer, which is partly mediated by long noncoding RNAs (lncRNAs). H19 is a lncRNA involving in cisplatin resistance in cancers. Valproic acid (VPA) is a commonly used drug for clinical treatment of seizure disorders. In addition, this drug may display its effects through regulation of noncoding RNAs controlling gene expression. The aim of the present study was the investigation of VPA treatment effect on H19 expression in ovarian cancer cells and also the relation of the H19 levels with apoptosis and cisplatin resistance. Briefly, treatment with VPA not only led to significant increase in apoptosis rate, but also increased the cisplatin sensitivity of A2780/CP cells. We found that following VPA treatment, the expression of H19 and EZH2 decreased, but the expression of p21 and PTEN increased significantly. To investigate the involvement of H19 in VPA-induced apoptosis and cisplatin sensitivity, H19 was inhibited by a specific siRNA. Our results demonstrate that H19 knockdown by siRNA induced apoptosis and sensitized the A2780/CP cells to cisplatin-induced cytotoxicity. These data indicated that VPA negatively regulates the expression of H19 in ovarian cancer cells, which subsequently leads to apoptosis induction, cell proliferation inhibition, and overwhelming to cisplatin resistance. The implication of H19→EZH2→p21/PTEN pathway by VPA treatment suggests that we could repurpose an old drug, valproic acid, as an effective drug for treatment of ovarian cancer in the future.     

Kinetics of oxidation of alcohols with tetramethylammonium fluorochromate

The oxidation of isopropyl, benzyl, and n-butyl alcohols to the corresponding aldehydes with tetramethylammonium fluorochromate was studied by spectrophotometry in acetonitrile solutions in the presence of p-toluenesulfonic acid. The reaction kinetics was studied under pseudo-first-order conditions with respect to the oxidizing agent. The Michaelis-Menten kinetics with respect to the substrate was observed, indicating the quasi-equilibrium formation of an oxidizing agent-alcohol complex. The formation constants and the rates of disproportionation of the complexes were determined. The temperature dependences of the reaction rates were studied, and the activation parameters were computed. A reaction scheme consistent with the observed results was proposed.__________Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 2, pp. 453–457, February, 2005.     

Determination of rhenium in geological materials by radiochemical neutron-activation analysis

A neutron-activation method for the determination of rhenium in geological materials is described. Radiochemical separation, using Re-carrier and liquid-liquid extractions, yields (186)Re in a state of radiochemical purity. The gamma-ray activity of the radionuclide is counted with an NaI(Tl) crystal scintillation detector, and the chemical yield is determined spectrophotometrically. Results for the contents of rhenium in the standard rock W-1 and in nickeliferous lateritic profiles are reported. Particular problems arising in neutron-activation analysis for rhenium in lunar surface materials are discussed.     

3D Microfibrous Scaffolds Selectively Promotes Proliferation and Glial Differentiation of Adult Neural Stem Cells: A Platform to Tune Cellular Behavior in Neural Tissue Engineering

Biomaterials are essential for the development of innovative biomedical and therapeutic applications. Biomaterials‐based scaffolds can influence directed cell differentiation to improve cell‐based strategies. Using a novel microfluidics approach, poly (ε‐caprolactone) (PCL), is used to fabricate microfibers with varying diameters (3–40 µm) and topographies (straight and wavy). Multipotent adult rat hippocampal stem/progenitor cells (AHPCs) are cultured on 3D aligned PCL microfibrous scaffolds to investigate their ability to differentiate into neurons, astrocytes, and oligodendrocytes. The results indicate that the PCL microfibers significantly enhance proliferation of the AHPCs compared to control, 2D planar substrates. While the AHPCs maintained their multipotent differentiation capacity when cultured on the PCL scaffolds, there is a significant and dramatic increase in immunolabeling for astrocyte and oligodendrocyte differentiation when compared with growth on planar surfaces. Our results show a 3.5‐fold increase in proliferation and 23.4‐fold increase in astrocyte differentiation for cells on microfibers. Transplantation of neural stem/progenitor cells within a PCL microfiber scaffold may provide important biological and topographic cues that facilitate the survival, selective differentiation, and integration of transplanted cells to improve therapeutic strategies.     

Experimental study of three-dimensional vortex structures in translating and rotating plates

Motivated by the unsteady force generation of flying animals, vortex formation and vorticity transport processes around small aspect-ratio translating and rotating plates with a high angle of attack are investigated. Defocusing Digital Particle Image Velocimetry was employed to explore the structure and dynamics of the vortex generated by the plates. For both translating and rotating cases, we observe the presence of a spanwise flow over the plate and the consequent effect of vorticity transport due to the tilting of the leading-edge vortex. While the spanwise flow is confined inside the leading-edge vortex for the translating case, it is widely present over the plate and the wake region of the rotating case. The distribution of the spanwise flow is a prominent distinction between the vortex structures of these two cases. As the Reynolds number decreases, due to the increase in viscosity, the leading-edge and tip vortices tend to spread inside the area swept by the rotating plate. The different vorticity distributions of the low and high Reynolds number cases are consistent with the difference in measured lift forces, which is confirmed using the vorticity moment theory.