Anti-obesity effects of escins extracted from the seeds of Aesculus turbinata BLUME (Hippocastanaceae)

To investigate the anti-obesity effects of escins extracted from the seeds of Aesculus turbinata BLUME, anti-obesity models in vitro and in vivo were employed. In a preliminary experiment, different solvent fractions of Aesculus turbinata BlUME as well as two isolated compounds were tested for their effects on pancreatic lipase (PL) in vitro. Subsequently, female ICR mice were fed a high fat diet with or without different concentrations of total escins for 11 weeks to examine body weight, parametrial adipose tissue weight, and hepatic triacylglycerol (TG) and total cholesterol (TC) contents. Plasma triacylglycerol levels (TG) after oral administration of lipid emulsions to rats were also investigated. The results showed that total escins (1 mg/ml) as well as two compounds isolated from total escins, namely escin Ib and IIa, showed inhibitory effects on PL activity. In vivo, total escins suppressed the increase in body weight, parametrial adipose tissue weight, TG content, and TC content in mice's liver; TG content in rat plasma was also reduced at 1, 2 and 3 h after oral administration of the lipid emulsion plus different concentrations of escins compared to those in the lipid emulsion groups. Meanwhile, mice fed a high fat diet plus 2% total escins for 3 d had an increased TG level in the feces compared to the HF group. The reason for this may be due to a delay in the intestinal absorption of dietary fat by inhibiting PL activity.     

Headspace Solid-Phase Microextraction/Gas Chromatography–Mass Spectrometry for the Determination of 2-Nonenal and Its Application to Body Odor Analysis

The odors and emanations released from the human body can provide important information about the health status of individuals and the presence or absence of diseases. Since these components often emanate from the body surface in very small quantities, a simple sampling and sensitive analytical method is required. In this study, we developed a non-invasive analytical method for the measurement of the body odor component 2-nonenal by headspace solid-phase microextraction coupled with gas chromatography–mass spectrometry by selective ion monitoring. Using a StableFlex PDMS/DVB fiber, 2-nonenal was efficiently extracted and enriched by fiber exposition at 50 °C for 45 min and was separated within 10 min using a DB−1 capillary column. Body odor sample was easily collected by gauze wiping. The limit of detection of 2-nonenal collected in gauze was 22 pg (S/N = 3), and the linearity was obtained in the range of 1–50 ng with a correlation coefficient of 0.991. The method successfully analyzed 2-nonenal in skin emissions and secretions and was applied to the analysis of body odor changes in various lifestyles, including the use of cosmetics, food intake, cigarette smoking, and stress load.     

Synthesis of hybrid resins via polysiloxane with methacryloyloxy groups

A polysiloxane derivative with methacryloyloxy groups (MPS) that was obtained from the reaction of polymeric tributylstannyl ester of silicic acid and (3‐methacryloyloxypropyl)dimethylchlorosilane was demonstrated to be a useful inorganic component for the preparation of organic–inorganic hybrid resins as nanocomposites. The copolymerizations of MPS with common monomers such as styrene, acrylonitrile, and methyl methacrylate proceeded readily at room temperature under UV irradiation to give the corresponding resins in good yields. The resins obtained from MPS and methyl methacrylate showed good transparency, hardness in a scratch test, and resistance to toluene but had poor flexibility. © 2000 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 39: 1–7, 2001     

In situ observation of protein-adsorbed stearic acid monolayer by Brewster angle microscopy and fluorescence microscopy

A fluorescence probe, fluorescein isothiocyanate (FITC), was introduced to proteins, and the morphology of protein-adsorbed stearic acid monolayer was observed by fluorescence microscopy and Brewster angle microscopy (BAM) in order to analyze images. At a low protein concentration, the surface pressure increased as shown by a sigmoidal curve. A number of stripe patterns in the BAM images increased and the shapes became clear with increasing concentration of proteins. Simultaneously, the size of circular islands also became small, and finally disappeared. These results suggest that the very large stripe patterns in the BAM image show the assembly of both proteins and stearic acid molecules, and small circular islands show only the stearic acid molecules. © 1998 John Wiley & Sons, Ltd.     

Enhanced electrical properties of highly oriented poly(vinylidene fluoride) films prepared by solid‐state coextrusion

Oriented poly(vinylidene fluoride) (PVDF) films with β‐form crystals have been commonly prepared by cold drawing of a melt‐quenched film consisting of α‐form crystals. In this study, we have successfully produced highly oriented PVDF thin films (20 µm thick) with β‐crystals and a high crystallinity (55–76%), by solid‐state coextrusion of a gel film to eight times the original length at an established optimum extrusion temperature of 160°C, some 10°C below the melting temperature. The resultant drawn films had a highly oriented (orientation function f_c = 0.993) fibrous structure, showing high mechanical properties of an extensional elastic modulus of 8.3 GPa and tensile strength of 0.84 GPa, along the draw direction. Such highly oriented and crystalline films exhibited excellent ferroelectric and piezoelectric properties. The square hysteresis loop was significantly sharper than that of a conventional sample. The sharp switching transient yielded the remnant polarization P_r of 90 mC/m², and the electromechanical coupling factor k_t was 0.24 at room temperature. These values are about 1.5 times greater than those of a conventional β‐PVDF film. Thus, solid‐state coextrusion near the melting point was found to be a useful technique for the preparation of highly oriented and highly crystalline β‐PVDF films with superior mechanical and electrical properties. The morphology of the extrudate relevant to such properties is discussed. © 1999 John Wiley & Sons, Inc. J Polym Sci B: Polym Phys 37: 2549–2556, 1999     

Rotational spectrum of the Ar–dimethyl sulfide complex

The rotational spectra of three isotopomers of the Ar–dimethyl sulfide (DMS) complex – normal, ³⁴S, and ¹³C species – were measured in the frequency region from 3.7 up to 24.1 GHz by Fourier transform microwave spectroscopy. The normal species yielded 43 a-type and 79 c-type transitions. No Ar tunneling splitting was observed, while many transitions were split by the internal rotation of the two methyl tops of the DMS unit. In cases where the K-type splitting was close to that due to methyl internal-rotation, several forbidden transitions were observed that followed b-type selection rules. All of the observed transition frequencies were analyzed simultaneously using a phenomenological Hamiltonian also used in previously published work describing the Ar–dimethyl ether (DME) and Ne–DME complexes. The rotational and centrifugal distortion constants and the potential barrier height to methyl-top internal rotation, V₃, were determined. The rotational constants were consistent with an Ar–DMS center of mass (cm) distance of 3.796 (3) Å and a S–cm–Ar angle of 104.8 (2)°. The V₃ potential barrier obtained, 736.17 (32) cm⁻¹, was 97.8% of the DMS monomer barrier. By assuming a Lennard–Jones-type potential, the dissociation energy was estimated to be 2.4 kJ mol⁻¹, which was close to the value for Ar–DME, 2.5 kJ mol⁻¹.