Isogeometric cable elements based on B-spline curves

Meccanica - In this paper, the isogeometric cable elements based on B-spline curves are developed for the static analysis of cable structures under conservative static loads. For this, the...     

Evaluation of transient turbulent flow fields using digital cinematographic particle image velocimetry

This paper describes an experimental development for temporal and spatial reconstruction of continuously varying flow fields by means of digital cinematographic particle image velocimetry (PIV). The system uses a copper-vapor laser illumination synchronized with a high-speed camera, and continuously samples at 250 fps to measure transient and non-periodic turbulent flows with relatively low frequencies, i.e., the surf zone turbulence produced by depth-limited wave break in a long laboratory flume. The use of the developed PIV system comprehensively records the temporal development of both phase-averaged and instantaneous turbulent vortex flows descended from the breaking waves to the bottom. Also, the measured power spectra show harmonic frequencies, ranging from the orbital frequency of 0.5 Hz up to the order of 5 Hz, and the well-known −5/3 dependence upon the turbulence fluctuation frequencies thereafter. Received: 2 December 1999/Accepted: 6 September 2000     

Ab initio study of the Trinem antibiotic Sanfetrinem GV104326

We present a theoretical calculation of trinem antibiotic sanfetrinem GV104326 and its cis-isomer of proton in β-lactam ring and methoxy inversion isomer. Ab initio Hartree Fock method is employed to calculate the geometry optimization; optimized parameters, bond lengths, bond angles and dihedral angles of isomers. We also calculated the vibrational frequencies, the IR intensities, the Raman activities and the thermochemical parameters. Mulliken population analysis is used to compare bond strength of an active site. These results are compared with available experimental data and other related theoretical calculations. The calculated IR spectra are in good agreement with experiments. Calculated geometrical and conformational structures of sanfetrinem and its isomers support the previous study of the geometrical requirements for the antibacterial activities. The significance of the rotational conformation of the carboxyl group to chemical reactivities is discussed.     

Synthesis of TiO<Subscript>2</Subscript> nanotubes using different alkaline media and their applications in photocatalysis and DSSCs

TiO₂ nanotubes (TNTs) were successfully synthesized from different alkaline media (i.e., NaOH and KOH) by using a microwave hydrothermal process. The effects of different alkaline media on the formation of TiO₂ nanotubes and their physicochemical properties were investigated. The phases of different TiO₂ nanostructures were studied by using X-ray diffraction patterns. Morphologies of the nanostructures were observed with a transmission electron microscope. The optical properties of the nanostructures were evaluated through the absorption behavior using UV–Vis diffuse reflectance spectroscopy. The photocatalytic activities of the TiO₂ nanostructures were evaluated by the degradation of methylene blue aqueous dye solution under the simulated solar light irradiation. Similarly, the photovoltaic efficiencies of the prepared samples were investigated by making photo-anode layers in the Dye Sensitized Solar Cells (DSSCs). The results revealed that in comparison to the single layered TiO₂ nanostructures in the DSSC, creation of a double layer structure significantly enhanced the efficiency of DSSC.     

Diffusion in multicomponent gaseous mixtures in a model of local thermodynamic equilibrium

Diffusion of chemical elements into an ionized multicomponent gaseous mixture is considered in a model of local thermodynamic equilibrium. A linear dependence of the mass flows of chemical elements and the heat flow on the temperature gradient, mass fractions of the chemical elements, and the electric field is obtained. An example is given of a calculation of the effective diffusion coefficients for a hydrogen-helium mixture.     

α,β-Unsaturated acyl cyanide synthesis via triethylamine catalyzed redox cyanation

Stereoselective redox cyanation of alkynyl aldehydes was explored, furnishing (E)-α,β-unsaturated acyl cyanides. This reaction was catalyzed by mild TEA base, as a dual role of Lewis base and Brönsted base. TMSCN treated with TEA was an effective reagent for generating umpolung intermediates from alkynyl aldehydes, and this nucleophilic intermediate can be protonated by equimolar amount of EtOH, promoting the efficient conversion into α,β-unsaturated acyl cyanides. The synthesized acyl cyanides were successfully applied as the synthetic precursors in the iron-catalyzed arylation reactions.     

Tone Image Classification and Weighted Learning for Visible and NIR Image Fusion

In this paper, to improve the slow processing speed of the rule-based visible and NIR (near-infrared) image synthesis method, we present a fast image fusion method using DenseFuse, one of the CNN (convolutional neural network)-based image synthesis methods. The proposed method applies a raster scan algorithm to secure visible and NIR datasets for effective learning and presents a dataset classification method using luminance and variance. Additionally, in this paper, a method for synthesizing a feature map in a fusion layer is presented and compared with the method for synthesizing a feature map in other fusion layers. The proposed method learns the superior image quality of the rule-based image synthesis method and shows a clear synthesized image with better visibility than other existing learning-based image synthesis methods. Compared with the rule-based image synthesis method used as the target image, the proposed method has an advantage in processing speed by reducing the processing time to three times or more.     

NRBF2-mediated autophagy contributes to metabolite replenishment and radioresistance in glioblastoma

Overcoming therapeutic resistance in glioblastoma (GBM) is an essential strategy for improving cancer therapy. However, cancer cells possess various evasion mechanisms, such as metabolic reprogramming, which promote cell survival and limit therapy. The diverse metabolic fuel sources that are produced by autophagy provide tumors with metabolic plasticity and are known to induce drug or radioresistance in GBM. This study determined that autophagy, a common representative cell homeostasis mechanism, was upregulated upon treatment of GBM cells with ionizing radiation (IR). Nuclear receptor binding factor 2 (NRBF2)—a positive regulator of the autophagy initiation step—was found to be upregulated in a GBM orthotopic xenograft mouse model. Furthermore, ATP production and the oxygen consumption rate (OCR) increased upon activation of NRBF2-mediated autophagy. It was also discovered that changes in metabolic state were induced by alterations in metabolite levels caused by autophagy, thereby causing radioresistance. In addition, we found that lidoflazine—a vasodilator agent discovered through drug repositioning—significantly suppressed IR-induced migration, invasion, and proliferation by inhibiting NRBF2, resulting in a reduction in autophagic flux in both in vitro models and in vivo orthotopic xenograft mouse models. In summary, we propose that the upregulation of NRBF2 levels reprograms the metabolic state of GBM cells by activating autophagy, thus establishing NRBF2 as a potential therapeutic target for regulating radioresistance of GBM during radiotherapy.Subject terms: Cancer metabolism, Prognostic markers