Different patterns of germination inhibition by carvacrol and thymol in Bacillus subtilis spores.

This study aimed to clarify how the phenolic monoterpene carvacrol and its structural isomer thymol both as essential oil components (EOCs) inhibit the germination of Bacillus subtilis spore. Germination was evaluated by the OD reduction rate in a growth medium and phosphate buffer containing either l-alanine (l-Ala) system or l-asparagine, d-glucose, d-fructose plus KCl (AGFK) system. The germination of the wild-type spores in the Trypticase Soy broth (TSB) was found to be greatly inhibited by thymol than by carvacrol.

Colloidal Stability of Emulsifier-free Oil-in-Water Emulsions: Effect of Oil Properties.

This study aims to determine the factors affecting the colloidal stabilization of emulsifier-free (EF) oil-in-water (O/W) emulsions prepared by mixing oil and water with a high-powered bath-type ultrasonicator (HPBath-US; 28 kHz, 300 W) in the absence of emulsifiers such as surfactants. The interrelation between the colloidal stability, oil properties (oil density, interfacial tension between oil and water, solubility parameter of oil, and oil viscosity), and emulsion properties (diameter and zeta-potential of oil droplets) of such EF-O/W emulsions were examined for this purpose. The colloidal stability of EF-vegetable oil-in-water emulsions (EF-VEG/W) was significantly higher than that of EF-hydrocarbon oil-in-water emulsions (EF-HDC/W) and EF-fatty acid-in-water emulsions (EF-FA/W).

Unimodal sized silica nanocapsules produced through water-in-oil emulsions prepared by sequential irradiation of kilo- and submega-hertz ultrasounds.

This study investigates the regulation of the size of 100 nm hollow-sphere silica particles using surfactant-free water-in-oil (W/O) emulsion. First, water droplets were dispersed in soybean oil sequential ultrasound irradiation (28 kHz → 200 kHz → 950 kHz). A precursor of hollow silica particles was prepared using hydrolysis and polymerization of methylsilyl trichloride into a stable W/O emulsion.

Colloidal Stability of Emulsifier-free Triolein-in-Water Emulsions: Effects of Temperature.

Herein, we report the colloidal stability of emulsifier-free (EF-) triolein-in-water (TO/W) emulsions prepared by mixing TO and water using a high-powered bath-type ultrasonicator (HPBath-US; 28 kHz, 300 W) in the absence of emulsifiers such as surfactants. In particular, the effect of the temperature (15-60℃) on the colloidal stability of EF-TO/W emulsions was examined because this is important for the practical application of EF-TO/W emulsions, for example, in foods, pharmaceuticals, and cosmetics. We found that the colloidal stability of the EF-TO/W emulsions decreased with increase in the temperature from 15 to 25°C, whereas it increased with increase in temperature from 25 to 40°C, and the high colloidal stability of the EF-TO/W emulsions was maintained above 40°C.

Pore-Mouth Structure of Highly Agglomerated Detonation Nanodiamonds.

Detonation nanodiamond aggregates contain water that is removed by thermal treatments in vacuo, leaving available pores for the adsorption of target molecules. A hard hydrogel of detonation nanodiamonds was thermally treated at 423 K for 2 h, 10 h, and 52 h in vacuo to determine the intensive water adsorption sites and clarify the hygroscopic nature of nanodiamonds. Nanodiamond aggregates heated for long periods in vacuo agglomerate due to the removal of structural water molecules through the shrinkage and/or collapse of the pores.

Unusual hygroscopic nature of nanodiamonds in comparison with well-known porous materials.

Nanodiamond aggregates have interparticle pores of 4.5 nm on average, exhibiting porous nature involved in their water storage. This work studies the hygroscopic nature of porous nanodiamond aggregates by water absorption based on liquid water droplets.

Inhibitory Effect of Spice Powders on the Development of Heated and Irradiated Bacillus subtilis Spores as Evaluated by Calorimetry.

Inhibitory effects of the powders of paprika, red pepper, black pepper, sage, oregano and thyme in a solid medium after heat treatment and gamma-irradiation on the development from spore of Bacillus subtilis were examined using calorimetry. Based on the f(t) curve (Antoce et al., 1996) from the thermogram obtained, two parameters, the growth rate constant and the growth retardation time, were used to evaluate the inhibitory effect.

Nanoporosity Change on Elastic Relaxation of Partially Folded Graphene Monoliths.

Fabrication of nanographene shows a promising route for production of designed porous carbons, which is indispensable for highly efficient molecular separation and energy storage applications. This process requires a better understanding of the mechanical properties of nanographene in their aggregated structure. We studied the structural and mechanical properties of nanographene monoliths compressed at 43 MPa over different times from 3 to 25 h.

In situ observation of Pt oxides on the low index planes of Pt using surface enhanced Raman spectroscopy.

In situ vibrational spectra of Pt oxides that cannot be measured with IR spectroscopy have been studied on the low index planes of Pt using surface enhanced Raman spectroscopy with bare Au nanoparticles (NPSERS). Two bands appear around 570 and 340 cm at higher potentials in 0.1 M HClO saturated with Ar, which are assigned to the stretching vibration of Pt-O(H) and the libration vibration of Pt-O, respectively.

Adsorption-desorption mediated separation of low concentrated DO from water with hydrophobic activated carbon fiber.

The adsorption and desorption of DO on hydrophobic activated carbon fiber (ACF) occurs at a smaller pressure than the adsorption and desorption of HO. The behavior of the critical desorption pressure difference between DO and HO in the pressure range of 1.25-1.

Water Adsorption Property of Hierarchically Nanoporous Detonation Nanodiamonds.

The detonation nanodiamonds form the aggregate having interparticle voids, giving a marked hygroscopic property. As the relationship between pore structure and water adsorption of aggregated nanodiamonds is not well understood yet, adsorption isotherms of N at 77 K and of water vapor at 298 K of the well-characterized aggregated nanodiamonds were measured. HR-TEM and X-ray diffraction showed that the nanodiamonds were highly crystalline and their average crystallite size was 4.

Essential Role of Viscosity of SWCNT Inks in Homogeneous Conducting Film Formation.

Newly developed inorganic single-wall carbon nanotube (SWCNT) inks of the Zn/Al complex and colloidal silica give a quite homogeneous SWCNT film on the polyethylene terephthalate (PET) substrate by the bar-coating method, whereas the surfactant-based SWCNT inks of sodium dodecyl sulfonate (SDS) and sodium dodecyl benzene sulfonate (SDBS) cannot give a homogeneous film. The key properties of SWCNT inks were studied for the production of homogeneous SWCNT films. The contact angle and surface tension of the inorganic dispersant-based SWCNT inks were 70° and 72 mN m(-1), respectively, being close to those of water (71.

Hydrogen-assisted fabrication of spherical gold nanoparticles through sonochemical reduction of tetrachloride gold(III) ions in water.

Spherical gold nanoparticles (AuNPs) were selectively synthesized through sonochemical reduction of tetrachloride gold(III) ions ([AuCl4](-)) in an aqueous solution of hydrogen tetrachloroaurate(III) tetrahydrate (HAuCl4 · 4H2O) with the aid of hydrogen (H2) gas in the absence of any additional capping agents. On the other hand, various shaped-AuNPs such as spherical nanoparticles, triangular and hexagonal plates were formed from sonochemical reduction of [AuCl4](-) in argon (Ar)-, nitrogen (N2)- or oxygen (O2)-purged aqueous [AuCl4](-) solutions. The selective fabrication of spherical AuNPs assisted by H2 gas is most likely attributed to the generation of hydrogen radicals (H) promoted by the reaction of H2 introduced and hydrogen oxide radicals (OH) produced by sonolysis of water.

Titania/CnTAB Nanoskeleton as adsorbent and photocatalyst for removal of alkylphenols dissolved in water.

We report here on the removal of alkylphenols (phenol, 4-n-propylphenol, 4-n-heptylphenol and 4-nonylphenol) dissolved in water using the composite particles of nanocrystalline titania and alkyltrimethylammonium bromide (CnH2n+1N(CH3)3Br, CnTAB; n=12, 14, 16 and 18) (named as TiO2/CnTAB Nanoskeleton) as adsorbents and photocatalysts. In particular, the adsorption of alkylphenols onto TiO2/CnTAB Nanoskeleton in water was investigated in terms of hydrophobic interaction between alkylphenols and CnTAB, surface area, pore structure and crystal size of TiO2/CnTAB Nanoskeleton. We revealed that CnTAB incorporated in the TiO2/CnTAB Nanoskeleton promotes the adsorption of alkylphenols onto TiO2/CnTAB Nanoskeleton due to the hydrophobic interaction between alkylphenols and CnTAB.

Stable surfactant-free toluene-polyethylene-in-water emulsion prepared by ultrasonication at high temperature.

A toluene-polyethylene (PE) mixture, only partially miscible at room temperature (RT), was ultrasonically dispersed in hot water, followed by immediate cooling to give a highly stable surfactant-free oil-in-water (O/W) emulsion. This temperature effect was correlated with physical gelation of the bulk mixture. Prolonged stabilization was achieved only through dispersion at a temperature (T(d)) above the gelation temperature (T(gel)) of the toluene-low-density PE (LDPE) mixture and subsequent rapid cooling.

Translocation of intratracheally instilled multiwall carbon nanotubes to lung-associated lymph nodes in rats.

In order to assess the extrapulmonary effects of multiwall carbon nanotubes (MWCNT), deposition of MWCNT and histopathologic changes in lung-associated lymph nodes (LALN) were examined in MWCNT-administered rats. At the age of 13 wk, male F344 rats were intratracheally instilled with MWCNT at a dose of 0 (vehicle), 40 or 160 μg/rat. The rats were sacrificed on Day 1, 7, 28 or 91 after instillation and light microscopic examinations were performed on LALN tissues.

Preparation of Highly Crystalline TiO(2) Nanostructures by Acid-assisted Hydrothermal Treatment of Hexagonal-structured Nanocrystalline Titania/Cetyltrimethyammonium Bromide Nanoskeleton.

Highly crystalline TiO(2) nanostructures were prepared through a facile inorganic acid-assisted hydrothermal treatment of hexagonal-structured assemblies of nanocrystalline titiania templated by cetyltrimethylammonium bromide (Hex-ncTiO(2)/CTAB Nanoskeleton) as starting materials. All samples were characterized by X-ray diffraction (XRD) and transmission electron microscopy (TEM). The influence of hydrochloric acid concentration on the morphology, crystalline and the formation of the nanostructures were investigated.

A facile route of gold nanoparticle synthesis and surface modification using amino-terminated poly(ethylene oxide)-poly(propylene oxide) block copolymers.

We report here a facile synthetic method and surface modification of gold nanoparticles using amino-terminated poly(ethylene oxide)-poly(propylene oxide) block copolymers (CH3-[OCH2CH2]x-[OCH2CH(CH3)]y-NH2; EO(x)PO(y)NH2) (SURFONAMINE) as media, reducing agents, stabilizing agents and surface-modifying agents. Gold nanoparticles were synthesized through autoreduction of hydrogen tetrachloroaureate(III) hydrate (HAuCl4 x 3H2O) by SURFONAMINE as media and reducing agents at ambient conditions (approximately 25 degrees C). The AuCl4- reduction and gold nanoparticle formation were promoted by SURFONAMINE with longer PEO segment and heating.

Facile preparation of gold nanoparticles-liposome composites.

We report here facile preparation of gold nanoparticles-liposome composites (AuNPs-liposome) in aqueous solutions at ambient conditions in the absence of any reducing agents and energy input. The AuNPs-liposomes were prepared by simply mixing of an aqueous solution of hydrogen tetrachloroaureate (III) hydrate (HAuCl4.3H2O) and a dispersion of poly(ethylene glycol)-grafted liposomes (PEG-liposomes) that are comprised of distearoyl-N-monomethyoxy poly(ethylene glycol)-succinyl-phosphatidylethanoamine (DSPE-PEG) and L-alpha-dipalmitoylphosphatidylcholine (DPPC).

Surface properties of surfactant-free oil droplets dispersed in water studied by confocal fluorescence microscopy.

The fluorescence spectrum of dye molecules, 4-(dicyanomethylene)-2-methyl-6-(p-dimethylaminostyryl)-4H-pyron (DCM), dissolved in surfactant-free n-decane droplets (average diameters of approximately 300 and approximately 2000 nm) dispersed in water was measured by a confocal microscope. The fluorescence spectra for 300- and 2000-nm droplets are found to exhibit a peak at 640 and 625 nm, respectively, and the peak red shifts with a decrease in the droplet diameter (solvatochromic shift of DCM molecules). It is concluded that (1) DCM molecules are located in a polar surface region of n-decane droplets and (2) the polarity increases with decreasing the droplet diameter.