Synthesis of ethanol-soluble few-layer graphene nanosheets for flexible and transparent conducting composite films.

We report a facile method of preparing few-layer graphene nanosheets (FLGs), which can be soluble in ethanol. Atomic force microscopy and high-resolution transmission electron microscopy studies reveal that FLGs have average thicknesses in the range of 2.6-2.8 nm, corresponding to 8-9 layers. A graphene/nafion composite film has a sheet resistance of 9.70 kΩ/sq at the transmittance of 74.5% (at 550 nm) while the nafion film on polyethylene terephthalate has a sheet resistance of 128 kΩ/sq at transmittance of 90.0%. For the cycling/bending test, almost no change in resistance was exhibited when the film was bent at an angle up to 140°, and no obvious deviation in resistance could be found after 100 bending cycles was applied. In addition, an FLGs-poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) composite layer was demonstrated as the effective hole transporting layer to improve the hole transporting ability in an organic photovoltaic device, with which the power conversion efficiency was enhanced from 3.10% to 3.70%. The results demonstrated the promising applications of FLGs on graphene-based electronics, such as transparent electrode and flexible conducting film.

Postpartum body composition changes in lactating and non-lactating primiparas.

The objective of this study is to evaluate the postpartum body composition changes in lactating versus non-lactating or formula-feeding primiparas during the first 12 wk. Twenty primiparous females (age range 17-35 y) who decided to nurse or formula feed their infant were studied. The non-lactating mothers (n = 6) were younger (21 versus 29 y) and had a lower prepregnancy weight (55 kg versus 63 kg) than the lactating mothers (n = 14). Body weight, height, waist and hip measurements, 3-d dietary and activity records, skin-fold thickness from triceps, suprailiac, midthigh, and midupper arm circumference, and total body composition were evaluated at three time periods (at delivery, at 6 wk, and at 12 wk postpartum). Total body composition for bone mineral, lean, and fat mass was measured by dual energy x-ray absorptiometry. At delivery and 6 wk postpartum, the weights and heights were similar between the two groups. By 12 wk postpartum, the formula-feeding group had a weight loss that was different from delivery, 66 +/- 10 kg to 59 +/- 8 kg, P < 0.03. There was no significant weight change in the lactating group during the study. The weight loss consisted of more lean mass than fat mass. The total body bone mineral content did not differ between the two groups during the study. Both groups had reduction in their waist size from delivery to 12 wk postpartum. But only the non-lactating mothers had reductions in their hip and midthigh measurements. There were no changes between the two groups in the skin-fold measurements. Lactating mothers had a higher total daily calories (1974 +/- 318 versus 1464 +/- 178 calories, P < 0.002) and fat intake (63 +/- 14 versus 47 +/- 9 g, P < 0.02) than the non-lactating mothers. The energy expenditure was similar between both groups. In conclusion, during the first 12 wk postpartum, non-lactating mothers who were younger and weighed less prepregnancy lost body weight and had more waist, hip, and midthigh size reductions compared to lactating mothers.

Design optimization of dome actuators.

This paper reports the conceptual design, analysis, and modeling of the electromechanical behavior of dome actuators. The geometric parameters of the actuator (dome thickness, width, radius, and depth), poling direction, electric field, and material properties (elastic compliance, piezoelectric constants, and dielectric permittivity) have been taken into account in the modeling work. The results of the analysis indicate that a dome actuator with a tangentially alternating poling direction and electric field (Case C) exhibits much larger displacement and force responses than dome actuators with other poling directions and electric fields. The first mode of natural frequency of the Case C dome actuator also was investigated, and its predicted performance was compared with that of moonie and rainbow actuators. The findings of this research clearly demonstrate the merit of design optimization of electromechanical devices.

Some observations on biodegradation of pollutants in aquatic systems.

The biodegradability of pollutants introduced into aquatic environments is subject to many variabilities characteristic of microbial processes. Some observations have been reported on studies with p-cresol, methyl parathion, benzo[b]thiophene, dibenzothiophene, 9H-carbazole, quinoline, benzo[f]quinoline, benz[a]anthracene, benzo[a]pyrene, 7H-dibenzo[c,g]carbazole, Mirex, 2,4-dichlorophenoxyacetic acid, Lindane and 1,1-bis(p-chlorophenyl)-2,2,2-trichloroethane analogs. Water reservoirs included a eutrophic stream, a eutrophic pond, an oligotrophic lake and effluents from waste-water treatment plants. The first ten of the above compounds were studied only in aerobic mixed-culture systems, and Mirex was studied with mixed cultures under both aerobic and anaerobic conditions. Examples were presented of the significance of cometabolism, diauxic processes, film fermentations and microbial interactions in biodegradation studies. Caution is advised in protocols regarding biodegradability of pollutants in aquatic environments.

Multiscale carbon nanotube-carbon fiber reinforcement for advanced epoxy composites.

We report an approach to the development of advanced structural composites based on engineered multiscale carbon nanotube-carbon fiber reinforcement. Electrophoresis was utilized for the selective deposition of multi- and single-walled carbon nanotubes (CNTs) on woven carbon fabric. The CNT-coated carbon fabric panels were subsequently infiltrated with epoxy resin using vacuum-assisted resin transfer molding (VARTM) to fabricate multiscale hybrid composites in which the nanotubes were completely integrated into the fiber bundles and reinforced the matrix-rich regions. The carbon nanotube/carbon fabric/epoxy composites showed approximately 30% enhancement of the interlaminar shear strength as compared to that of carbon fiber/epoxy composites without carbon nanotubes and demonstrate significantly improved out-of-plane electrical conductivity.

Klebsiella pneumoniae-induced mycotic aneurysm of the abdominal aorta complicated by bloody pleural effusion--a case report.

A 68-year-old diabetic male who suffered from recurrent severe lumbago and high fever was found to have mycotic abdominal aneurysm. His symptoms did not improve after maximum-dose antibiotic therapy. Bloody pleural effusion on the left side was noticed hours before he expired. Klebsiella pneumoniae alone was isolated from blood from cellulitis-related bacteremia, when aneurysm formation was complete and later from bloody pleural effusion. To our knowledge, this is the first report of mycotic abdominal aneurysm of solely Klebsiella pneumoniae complicated by bloody pleural effusion.

Determination of the components in a Chinese prescription, yu-ping-feng san, by RAPD analysis.

In this study, the RAPD (random amplified polymorphic DNA) technique was employed for the first time to determine the components in a Chinese herbal prescription. Forty decamer oligonucleotide primers were screened in the RAPD analysis to identify three Chinese medicines, the dried root of Astragalus membranaceus (Fisch.) Bge., the dried root of Ledebouriella seseloides Wolff, and the dried rhizome of Atractylodes macrocephala Koidz, in a Chinese prescription. Only primer OPP-10 simultaneously generated three distinct markers were each specific to one component. The marker with 200 bp is specific to Astragalus membranaceus; the 440 bp marker is specific to Atractylodes macrocephala; and the remaining marker with 500 bp was present in Ledebouriella seseloides. The presence of the three herbal medicines in the mixed sample, the Chinese prescription, was determined when the primer OPP-10 RAPD reaction was performed. The technique was proved to contribute to the identification of components in the Chinese medicinal preparations.

Production of an autoinhibitor by a thermophilic bacillus.

Premature cessation of rapid, exponential growth and a low final cell yield were observed with a thermophilic bacillus in a glucose-mineral salts-vitamin medium. Restricted growth was not due to nutrient or oxygen limitation, to depressed pH, or to the physical effects of "crowding." Glucose conversion to cellular material was efficient at a low glucose charge (0.1%), but decreased with increasing concentrations of glucose. The likelihood that an autoinhibitor(s) was being produced was considered. Further studies revealed that an autoinhibitor appeared in the culture supernatant fluid at the end of the exponential phase. The factor was soluble in 75% ethanol which precipitated a large amount of extracellular slime. The crude inhibitor in the alcohol filtrate was dialyzable and withstood 3 hr of incubation at pH 2 or 12, and 30 min of boiling.

Influence of phosphate compounds on certain fungi and their preservative effects on fresh cherry fruit (Prunus cerasus, L.).

Studies were conducted to ascertain the retarding effects of four phosphate compounds (sodium hexametaphosphate, sodium tripolyphosphate, sodium tetraphosphate, and tetrasodium pyrophosphate) on molding of fresh cherries (Prunus cerasus, L.). In vitro studies on their antimycotic effects against the most common fungal spoilers, Penicillium expansum, Rhizopus nigricans, and Botrytis sp., were also carried out. Sodium tetraphosphate appeared to be the most effective compound in preserving cherries and also had the greatest antimycotic effects in the in vitro studies. A 10% concentration, when applied as a dip, inhibited fungal growth on fresh cherries for up to 30 days of storage at 1.1 C (34 F) and a relative humidity of 94%, whereas untreated controls showed fungal growth at 14 days. Following in order of effectiveness were sodium hexametaphosphate, sodium tripolyphosphate, and tetrasodium pyrophosphate.