Woo-Jae Kim

p -Hydroxybenzene diazonium salt was utilized to selectively functionalize metallic single-walled carbon nanotubes (SWNT) at 45 °C with high selectivity. Deprotonation in alkaline solution induces a negative charge on the functionalized SWNT for electrophoretic separation. We applied this concept to enrich metallic and semiconducting fractions separately using the induced differences in electrophoretic mobilities. Free solution electrophoresis was utilized to separate selectively reacted samples

We show that covalently attached functional groups can alter the densities of individual single-walled carbon nanotubes (SWNTs) in a predictable and highly controllable manner. A volume-additivity model based on molecular group contributions can be used to estimate the density difference between 4-hydroxyphenyl-functionalized and nonfunctionalized HiPco SWNTs as approximately 98.3 kg/m 3, compared with 97.9 kg/m 3 measured by density-gradient centrifugation. Conversely, the estimated density dif

Ceramide is a lipid second messenger derived from the hydrolysis of sphingomyelin by sphingomyelinases (SMases) and implicated in diverse cellular responses, including growth arrest, differentiation, and apoptosis. Defects in the neutral SMase (nSMase) gene Smpd3, the primary regulator of ceramide biosynthesis, are responsible for developmental defects of bone; regulation of ceramide levels have been implicated in macrophage differentiation, but this pathway has not been directly implicated in h

Abstract Current thermochemical methods to generate H 2 include gasification and steam reforming of coal and natural gas, in which anthropogenic CO 2 emission is inevitable. If biomass is used as a source of H 2 , the process can be considered carbon-neutral. Seaweeds are among the less studied types of biomass with great potential because they do not require freshwater. Unfortunately, reaction pathways to thermochemically convert salty and wet biomass into H 2 are limited. In this study, a cata

La oxide is known to be the best promoter among reducible metal oxides for acetylene hydrogenation. However, it requires high-temperature reduction, which is not feasible in commercial processes. To maintain the enhanced catalytic performance by La oxide addition while lowering the reduction temperature for application in commercial process, we added Ti oxide as a second promoter, which has a higher reducibility than La oxide. The Ti oxide is added to the Pd surface, which has been partially cov

A hybrid film consisting of zinc oxide nanoparticles (ZnO NPs) and carbon nanotubes (CNTs) is formed on a glass substrate using a simple and swift spin coating process for the use in ultraviolet photodetectors (UV PDs). The incorporation of various types of CNTs into ZnO NPs (ZnO@CNT) enhances the performance of UV PDs with respect to sensitivity, photoresponse, and long-term operation stability when compared with pristine ZnO NP films. In particular, the introduction of single-walled CNTs (SWNT

DNA double-strand breaks can be introduced by exogenous agents or during normal cellular processes. Genes belonging to the RAD52 epistasis group are known to repair these breaks in budding yeast. Among these genes, RAD52 plays a central role in homologous recombination and DNA double-strand break repair. Despite its importance, its mechanism of action is not yet clear. It is known, however, that the human homologue of Rad52 is capable of binding to DNA ends in vitro. Herein, we show that Rad22 p