Effect of nanogroove geometry on adipogenic differentiation

We present the effect of nanotopographically defined surfaces on adipocyte differentiation using various nanogroove patterns. Parallel nanogroove arrays with equal inter-groove distance (400, 550, 800?nm width) and varying distances (550?nm width with three different spacings of 550, 1100, and 2750?nm) were fabricated by UV-assisted capillary force lithography (CFL) on 18?mm diameter glass coverslips using biocompatible polyurethane (PU)-based material. After coating with fibronectin and subsequent culture of 3T3-L1 preadipocytes, the degree of adipocyte differentiation was determined by Oil Red O staining and adipogenic gene expression. We observed that adipocyte differentiation was slightly but substantially affected by culture on various nanogrooved surfaces. In particular, the cell crawling into nanogrooves contributed substantially to an enhanced level of differentiation with higher contact guidance, suggesting that cell-to-surface interactions would play a role for the adipocyte differentiation.     

Raspberry juice consumption, oxidative stress and reduction of atherosclerosis risk factors in hypercholesterolemic golden Syrian hamsters

The effects of raspberries on early atherosclerosis in Syrian hamsters were investigated using three juices prepared from var. Cardinal, Glen Ample and Tulameen berries. The hamsters received an atherogenic diet for 12 weeks and at the same time a juice at a daily dose corresponding to the consumption of 275 ml by a 70 kg human. A control group received the same diet with water instead juice. The principal polyphenolic compounds in the juices were anthocyanins and ellagitannins, which were present at concentrations of 218-305 μg mL(-1) and 45-72 μg mL(-1), respectively. The three juices had similar but not identical effects. They all inhibited cardiac and aortic production of superoxide anion and increased hepatic glutathione peroxidase activity although only Tulameen juice brought about a significant increase in superoxide dismutase activity. Glen Ample was the only juice to significantly increase plasma paraoxonase activity. All the juices lowered plasma triglyceride level while consumption of Tulameen and Cardinal, but not Glen Ample, significantly lowered plasma total cholesterol and LDL-cholesterol. Cardinal was the sole juice to significantly increase HDL-cholesterol and likewise it also significantly reduced body weight. These findings suggest that moderate consumption of raspberry juices can help to prevent the development of early atherosclerosis, with the underlying mechanisms related to improved antioxidant status and serum lipid profiles.     

A study of fluid dynamics parameters for prediction of obstructive sleep apnea

Obstructive sleep apnea (OSA) is a syndrome characterized by the repetitive episodic collapse of the upper airway. The purpose of this study is to investigate the fluid dynamic parameters for the prediction of obstructive sleep apnea in the upper airway before and after setback surgery. Here, we analyzed the flow phenomena of inspiration and expiration in obstructive sleep apnea patients. The modeling of the upper airway was performed with facial 3 dimensional facial computed tomography images (3D facial CT). We used timedependent value for boundary conditions. The changes of pressure were studied with 3D facial CT taken both before and after the setback surgery. Further, it was found that the correlation between PSG data and non-dimensional pressure drop can be used to predict the severity of OSA. In all 6 patients except for patient 1, the average values of the non-dimensional pressure drops and PSG clinical data are inversely related. For each patient, the lower the pressure drop is, the higher the PSG values will be.     

Lightweight design of airlift provision for Korean light tactical vehicle using approximate optimization

Journal of Mechanical Science and Technology - A tactical vehicle should have air transportability for rapid attack and should satisfy its basic role for ground transportation. Airlift provision...     

Prediction of homogeneous combustion by modification of the fuel combustion mechanism in a DME fueled CI engine

Journal of Mechanical Science and Technology - This study was performed to predict numerically the homogeneous combustion characteristics where the fuel combustion mechanism was modified in a DME...     

Phenolic components from the leaves of Panax ginseng and their effects on HL-60 human leukemia cells

This study investigates phenolic components from the Panax ginseng C.A. Meyer leaves led to the isolation of 3 flavonoids (1–3). Their structures were characterized on the basis of physicochemical properties, nuclear magnetic resonance (NMR) spectra, electron spray ionization-mass spectrometry (ESI-MS) data, and comparison with those in the literature. Of them, sophoraflavonoloside (2) and prunin (3) were found to inhibit the growth of HL-60 human leukemia cells with IC₅₀ in values of 29.8 and 21.4 μM by the induction of apoptosis.     

High-performance active gate drive for high-power IGBT's

This paper deals with an active gate drive (AGD) technology for high-power insulated gate bipolar transistors (IGBTs). It is based on an optimal combination of several requirements necessary for good switching performance under hard-switching conditions. The scheme specifically combines together the slow drive requirements for low noise and switching stress and the fast drive requirements for high-speed switching and low switching energy loss. The gate drive can also effectively dampen oscillations during low-current turn-on transient in the IGBT. This paper looks at the conflicting requirements of the conventional gate drive circuit design and demonstrates using experimental results that the proposed three-stage AGD technique can be an effective solution     

Increasing of stability depended on the position of alkoxy group in PPV

In order to prevent the photo oxidation of the vinylene group of poly(p-phenylenevinylene) (PPV) series, the poly(p-phenylenedifluorovinylene) (PPDFV) derivatives with difluoro groups on vinylene unit were synthesized by Gilch polymerization using potassium tertbutoxide. The stability of the PPDFV backbone is attributed to the electron-withdrawing effect of the fluoro groups which prohibit the initial step of [2+2] cycloaddition for the oxidation of the vinylene unit. In photo-degradation experiments with white light, the PL spectra of m-EHOPh-PPDFV film is blue shifted about 19 nm and the optical density of the side peak at 380 nm is increased to 0.5 atomic unit. In case of p-EHOPh-PPDFV, the PL spectra show almost same maxima peaks at 448–450 nm after irradiation from 1 h to 5 h. p-EHOPh-PPDFV with para-alkoxy phenyl group shows very stable PL spectra against photo oxidation as compared to the case of m-EHOPh-PPDFV with meta-alkoxy phenyl group.     

Structural Characterization of Receptor–Receptor Interactions in the Allosteric Modulation of G Protein-Coupled Receptor (GPCR) Dimers

G protein-coupled receptor (GPCR) oligomerization, while contentious, continues to attract the attention of researchers. Numerous experimental investigations have validated the presence of GPCR dimers, and the relevance of dimerization in the effectuation of physiological functions intensifies the attractiveness of this concept as a potential therapeutic target. GPCRs, as a single entity, have been the main source of scrutiny for drug design objectives for multiple diseases such as cancer, inflammation, cardiac, and respiratory diseases. The existence of dimers broadens the research scope of GPCR functions, revealing new signaling pathways that can be targeted for disease pathogenesis that have not previously been reported when GPCRs were only viewed in their monomeric form. This review will highlight several aspects of GPCR dimerization, which include a summary of the structural elucidation of the allosteric modulation of class C GPCR activation offered through recent solutions to the three-dimensional, full-length structures of metabotropic glutamate receptor and γ-aminobutyric acid B receptor as well as the role of dimerization in the modification of GPCR function and allostery. With the growing influence of computational methods in the study of GPCRs, we will also be reviewing recent computational tools that have been utilized to map protein–protein interactions (PPI).