On the equations of motion for rigid bodies with surface growth

Appropriate balance equations are formulated for a body whose geometry, mass and inertia vary due to surface growth. The distance between any two particles of the body is assumed to be fixed and hence several interesting simplifications of the balance laws occur. In particular, a set of ordinary differential equations for the attitude and position of the body are developed. The dynamics predicted by these equations for a body moving on an incline, and gathering mass as it does so, are discussed.     

Soybean (Glycine max L. Merr.) hexane extracts inhibit cellular fatty acid uptake by reducing the expression of fatty acid transporters

Intake of saturated and trans-fatty acids is a strong risk factor for coronary heart disease. We investigated the inhibitory effects of 2 hexane extracts from white (WBE) and black soybeans (BBE) on cellular fatty acid uptake in vitro. Transcellular uptake of elaidic acid (t18:1), a major trans-fatty acid present in processed foods, in Caco-2 monolayers was significantly reduced by 28.3 and 16.7% 60 min after WBE and BBE treatment, respectively. Results of flow cytometry (FACS) analysis showed significant reductions in boron-dipyrromethene (BODIPY) fluorescence-labeled fatty acid uptake by 35.4 and 40.2% with WBE and BBE treatment, respectively. BBE treatment significantly reduced the expression of fatty acid transport protein-4 and CD36 in Caco-2 cells, as determined by quantitative real time-polymerase chain reaction (qRT-PCR). Similar trends were found in WBE treatment, although to a lesser degree. These observations suggest that soybean extract may reduce fatty acid uptake and cellular fat accumulation by altering fatty acid transporter expression.     

The effect of Ne+ ion implantation on polyimide film

The fluence of Ne⁺ ion irradiation on the surface modification of polyimide (Kapton HN type) film was investigated. The irradiation of ion implantation onto a polyimide film was performed, and the surface chemical structure was analyzed in detail by X-ray photoelectron spectroscopy (XPS). An acceleration voltage of 100 keV was used in the ion implantation with different doses from 5 × 10¹⁴ to 5 × 10¹⁷ ion cm^?2 and a beam current density of 10 μA cm^?2. The elemental ratios of carbon, oxygen and nitrogen were calculated from 1s peaks of the corresponding elements. The results showed that the content of carbon in the surface layer increased after ion irradiation, while the ratios of oxygen decreased after irradiation, especially in the case of the polyimide film treated at ion fluence. The O1s spectra after ion irradiation are related to the rearrangement of those recoil atoms and the ion incorporated into the film and the formation of new types of bond, such as C–O and O–O.     

Fabrication and characterization of the mechanical properties of multi-walled carbon nanotube-reinforced epoxy resins by e-beam irradiation

In this study, the multi-walled carbon nanotubes (MWNT) were reinforced to epoxy resin as fabrication of epoxy/MWNT nanocomposites by electron beam (e-beam) curing. An attempt is made to disperse MWNT into diglycidyl ether of bisphenol A (DGEBA) as epoxy resins, using triarylsulfonium hexafluoroantimonate (TASHFA) as an initiator. E-beam irradiation effect on the curing of the epoxy resin was investigated in oxygen and nitrogen atmospheres at room temperature. The flexural modulus was measured by a universal testing machine (UTM). Here, the flexural modulus factor exhibits an upper limit at 0.3 wt% MWNT. The dynamic mechanical and thermal properties of the irradiated epoxy resins were characterized using DMA, DSC and TGA machines. DMA curves of the storage modulus revealed an increase with an increasing MWNT content and radiation dose. However, the T_g curve decreased as a function of the increasing MWNT content and radiation dose. The thermal properties of the TGA and DSC data were improved by increasing the content of the MWNT and the radiation dose. Likewise, the thermal properties were stabilized by increasing the amount of initiator and irradiating the resins in a nitrogen atmosphere.     

Characterization of polyacrylonitrile based carbon nanofiber mats via electron beam processing

The aim of this study was to evaluate the ability of electron beam irradiation to drive stabilization reactions within PAN nanofiber mats to obtain carbon nanofiber mats. PAN nanofiber mats with fiber diameters of 300-400 nm were prepared via an electrospinning method. Electrospun PAN nanofiber mats were stabilized by electron beam irradiation with various doses up to 5,000 kGy. Using the irradiation-stabilized PAN nanofiber mats, carbon nanofibers were obtained by pyrolysis in a tube furnace for 1 h at 1,000 degrees C under an N2 atmosphere. FT-IR analysis indicated that the transformation of C[triple bond]N groups to C==N groups was accelerated by electron beam stabilization. The thermal behavior of the PAN nanofiber mats was studied using DSC and TGA. DSC thermograms showed that the peak temperatures of the exothermic reactions were found to decrease with increasing electron beam irradiation doses. Irradiation-stabilized PAN nanofiber mats were not observed to dramatically decrease in weight between 290 degrees C and 320 degrees C, an observation presumed to be related to cyclization. The char yields of PAN were found to increase with increasing irradiation doses.     

Biological functions of a synthetic compound,octadeca-9,12-dienyl-3,4,5-hydroxybenzoate,from gallic acid–linoleic acid ester

Octadeca-9,12-dienyl-3,4,5-hydroxybenzoate (GA-LA) was synthesized chemically from gallic acid and linoleic acid ester and its biological function was investigated for further application purpose. This newly synthesized compound GA-LA possesses a strong and synergistic effect on cancer cell proliferation inhibition; however, no synergistic effect was found for 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity, ferric reducing antioxidant power (FRAP), and inhibition effect against xanthine oxidase, hyaluronidase, and tyrosinase. Nevertheless, synthetic GA-LA possessed comparable biological activities when compared with gallic acid and tocopherol. With anti-mutagenic activity it can be concluded that this compound may be a useful functional material for the food, pharmaceutical, and cosmetic industry.     

Toxicological evaluation of the isoflavone puerarin and its glycosides

Puerarin, an isoflavone derived from kudzu roots, has strong biological activities. However, its bioavailability in vivo is often limited by its insolubility. A novel transglycosylase increases the solubility of puerarin >100-fold, by converting it to puerarin glycosides. Since over-consumption of an isoflavone might have toxic effects, therefore, we investigated the potential antimutagenic activity, bone marrow micronucleus test, and a 28-day oral repeated administration test with puerarin and its glycosides. In Ames tests, neither puerarin nor its glycosides exhibited mutagenic effects up to 200 μg/plate. Puerarin and its glycoside, glucosyl-α-(1,6)-puerarin, significantly reduced the mutagenic effect of 4-nitroquinoline-1-oxide by up to 41%. In bone marrow micronucleus tests using ICR mice, neither puerarin nor glucosyl-α-(1,6)-puerarin interfered with erythrocyte production in the bone marrow. Both compounds decreased the prevalence of polychromatic erythrocytes. Sprague–Dawley rats were orally dosed with puerarin and its glycosides daily for 28 days. Neither puerarin nor its glycosides caused significant alterations in histology, and biochemical and hematologic parameters. These results suggest that puerarin and its glycosides do not have significant toxic effects, at least in rodents, either in vitro or in vivo at doses of up to 250 mg/kg per day.     

Preparation of chelating fabrics by radiation‐induced grafting of itaconic acid and acrylonitrile onto polypropylene nonwoven fabrics and subsequent amination of graft copolymer

A mixture of acrylonitrile (AN) and itaconic acid (IA) was cografted onto polypropylene (PP) nonwoven fabrics by preirradiation method. The effects of graft polymerization conditions such as temperature, reaction time, Mohr's salt concentration, solvent mixture ratio, and comonomer composition on the total grafting yield were investigated. The addition of AN as a comonomer increased the amount of IA that reacted with PP fabrics. An increase in the temperature from 40 to 60°C increased the grafting rate, but the final grafting yield decreased at high temperature. The addition of 0.01 wt % Mohr's salt to the reaction medium leaded to a sharp increase of grafting yield. The accelerative effect of solvent medium on the grating yield was higher in dimethylformamide (DMF) and methanol mixtures, when compared with DMF or methanol. Chelating fabrics was synthesized by subsequent amination of grafted fabric with ethylene diamine (EDA) and phenylhydrazine (PH). The conversion yield reached maximum value at about 90% for 80% PP‐g‐AN‐IA fabrics at 90°C. At same amination conditions, the conversion yield is higher when PP‐g‐AN‐IA fabrics react with EDA compared with PH. FT‐IR data indicate that amine groups were introduced onto PP‐g‐AN‐IA fabric through amide linkage between grafted AN or IA and EDA or PH. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011