In this work, we report in-situ observations of changes in catalyst morphology, and of growth termination of individual carbon nanotubes (CNTs), by complete loss of the catalyst particle attached to it. The observations strongly support the growth-termination mechanism of CNT forests or carpets by dynamic morphological evolution of catalyst particles induced by Ostwald ripening, and sub-surface diffusion. We show that in the tip-growth mode, as well as in the base-growth mode, the growth termination of CNT by dissolution of catalyst particles is plausible. This may allow the growth termination mechanism by evolution of catalyst morphology to be applicable to not only CNT forest growth, but also to other growth methods (for example, floating-catalyst chemical vapor deposition), which do not use any supporting layer or substrate beneath a catalyst layer.

We have used bulked segregant analysis to screen the strain-specific DNA marker associated psychrophilic strain of Pleurotus eryngii. Bulked genomic DNAs of Pleurotus eryngii were amplified by randomly amplified polymorphic DNA (RAPD) using OP-A, OP-B, OP-L, OP-P, OP-R and OP-S primers to screen the strain-specific DNA marker. A unique DNA fragment of 490 bp was amplified with OP-L18 primer from the psychrophilic strain and sequenced. A sequence characterized amplified region (SCAR) marker was designed on the basis of the determined sequence and named as OP-L18-1. The PCR analysis with the OP-L18-1 primer showed that this SCAR marker clearly distinguish the psychrophilic strains from the control strains.

Silk fibroin can be damaged or degraded during degumming process. Therefore, it is expected that different structure and properties of silk fibroin can be obtained by different degumming method. However, effect of degumming method on the structure and properties of regenerated silk has not been considered, yet. In this study, Effect of degumming method on the structure and properties of solution, film, and electrospun fiber of regenerated silk was examined. Order of viscosity of regenerated silk solution as follows : Urea method > Acid method, HTHP method > Soap/soda method, Soda method. This viscosity difference among the degumming method strongly influenced the electro-spinning performance of regenerated silk perpared from different degumming method. Also, solution turbidity, crystallinity index (from FTIR), mechanical properties of silk were remarkably affected by degumming method.

Methanol as a carbon source in chemical vapor deposition (CVD) graphene has an advantage over methane and hydrogen in that we can avoid optimizing an etching reagent condition. Since methanol itself can easily decompose into hydrocarbon and water (an etching reagent) at high temperatures [1], the pressure and the temperature of methanol are the only parameters we have to handle. In this study, synthetic conditions for highly crystalline and large area graphene have been optimized by adjusting pressure and temperature; the effect of each parameter was analyzed systematically by Raman, scanning electron microscope, transmission electron microscope, atomic force microscope, four-point-probe measurement, and UV-Vis. Defect density of graphene, represented by D/G ratio in Raman, decreased with increasing temperature and decreasing pressure; it negatively affected electrical conductivity. From our process and various analyses, methanol CVD growth for graphene has been found to be a safe, cheap, easy, and simple method to produce high quality, large area, and continuous graphene films.

Carbon nanotubes (CNTs) have exceptional mechanical, electrical, and thermal properties compared with those of commercialized high-performance fibers. For use in the form of fabrics that can maintain such properties, individual CNTs should be held together in fibers or made into yarns twisted out of the fibers. Typical methods that are used for such purposes include (a) surfactant-based coagulation spinning, which injects a polymeric binder between CNTs to form fibers; (b) liquid-crystalline spinning, which uses the nature of CNTs to form liquid crystals under certain conditions; (c) direct spinning, which can produce CNT fibers or yarns at the same time as synthesis by introducing a carbon source into a vertical furnace; and (d) forest spinning, which draws and twists CNTs grown vertically on a substrate. However, it is difficult for those CNT fibers to express the excellent properties of individual CNTs as they are. As solutions to this problem, post-treatment processes are under development for improving the production process of CNT fibers or enhancing their properties. This paper discusses the recent methods of fabricating CNT fibers and examines some post-treatment processes for property enhancement and their applications.

The mushrooms have been used as traditional medicines and food resources in many countries. The objective of this study was to determine antioxidant compounds and to evoluate tyrosinase inhibitory activity of extracts from Hypsizigus marmoreus. The pileus and stipe of Hypsizigus marmoreus were extracted with methanol and water, separately. The methanol extract of Hypsizigus marmoreus were fractioned by hexane, chloroform, ethylacetate and buthanol. The concentrations of total polyphenolics and flavonoids in methanol extracts were investigated by colorimetric methods. The concentrations of total polyphenolics and flavonoids in methanol extract of the pileus was higher than methanol extract of the stipe. The DPPH redical scavenging activity of the pileus extract was also higher than stipe extract in methanol extract. The IC50 of DPPH redical scavenging activity of the pileus and stipe in methanol extract were 18 mg/ml and 1 10 mg/ml, respectively. The IC50 of tyrosinase inhibitory activity of the pileus and stipe in methanol extract were 500 mg/ml and 1,000 mg/ml in methanol extract. These results suggest that Hypsizigus marmoreus can be potentially used as a source of natural antioxidant agent in the cosmetic industry as well as the food, pharmaceutical and medicinal industry.