Control of a two-dimensional (2D) structure of assembled graphene oxide (GO) sheets is highly desirable for fundamental research and potential applications of graphene devices. We show that an alkylamine surfactant, i.e., octadecylamine (ODA), Langmuir monolayer can be utilized as a template for adsorbing highly hydrophilic GO sheets in an aqueous subphase at the liquid-gas interface. The densely packed 2-D monolayer of such complex films was obtained on arbitrary substrates by applying Langmuir-Schaefer or Langmuir-Blodgett technique. Morphology control of GO sheets was also achieved upon compression by tuning the amount of spread ODA molecules. We found that ODA surfactant monolayers prevent GO sheets from sliding, resulting in formation of wrinkling rather than overlapping at the liquid-gas interface during the compression. The morphology structures did not change after a graphitization procedure of chemical hydrazine reduction and thermal annealing treatments. Since morphologies of graphene films are closely correlated to the performance of graphene-based materials, the technique employed in this study can provide a route for applications requiring wrinkled graphenes, ranging from nanoelectronic devices to energy storage materials, such as supercapacitors and fuel cell electrodes.

An extracellular beta-glucosidase was purified 154-fold to electrophoretic homogeneity from the brown-rot basidiomycete Fomitopsis palustris grown on 2.0% microcrystalline cellulose. SDS-polyacrylamide gel electrophoresis gel gave a single protein band and the molecular mass of purified enzyme was estimated to be approximately 138 kDa. The amino acid sequences of the proteolytic fragments determined by nano-LC-MS/MS suggested that the protein has high homology with fungal beta-glucosidases that belong to glycosyl hydrolase family 3. The Kms for p-nitorophenyl-beta-D-glucoside (p-NPG) and cellobiose hydrolyses were 0.117 and 4.81 mM, and the Kcat values were 721 and 101.8 per sec, respectively. The enzyme was competitively inhibited by both glucose (Ki= 0.35 mM) and gluconolactone (Ki= 0.008 mM), when p-NPG was used as substrate. The optimal activity of the purified beta-glucosidase was observed at pH 4.5 and 70 degrees. The F. palustris protein exhibited half-lives of 97 h at 55 degrees and 15 h at 65 degrees, indicating some degree of thermostability. The enzyme has high activity against p-NPG and cellobiose but has very little or no activity against p-nitrophenyl-beta-lactoside, p-nitrophenyl-beta-xyloside, p-nitrophenyl-alpha-arabinofuranoside, xylan, and carboxymethyl cellulose. Thus, our results revealed that the beta-glucosidase from F. palustris can be classified as an aryl-beta-glucosidase with cellobiase activity.

The feasibility conditions of interference alignment (IA) are analyzed for reverse TDD systems, i.e., one cell operates as downlink (DL) but the other cell operates as uplink (UL). Under general multiple-input and multiple-output (MIMO) antenna configurations, a necessary condition and a sufficient condition for one-shot linear IA are established, i.e., linear IA without symbol or time extension. In several example networks, optimal sum degrees of freedom (DoF) is characterized by the derived necessary condition and sufficient condition. For symmetric DoF within each cell, a sufficient condition is established in a more compact expression, which yields the necessary and sufficient condition for a class of symmetric DoF. An iterative construction of transmit and received beamforming vectors is further proposed, which provides a specific beamforming design satisfying one-shot IA. Simulation results demonstrate that the proposed IA not only achieve lager DoF but also significantly improve the sum rate in the practical signal-to-noise ratio (SNR) regime.Index Terms-Degrees of freedom, dynamic TDD, feasibility conditions, heterogeneous networks, interference alignment, multiple-input and multiple-output (MIMO), reverse TDD.

No abstract

A yellow-pigmented, rod-shaped, Gram-staining-negative, aerobic bacterial strain, designated CJ7 T , was isolated from a freshwater lake at Chung-Ang University in Anseong, South Korea. Results from 16S rRNA gene sequence analysis revealed that the isolate was phylogenetically affiliated with members of the genus Flavobacterium. Strain CJ7 T showed sequence similarity values of 91.5-98.0 % to the type strains of recognized Flavobacterium species. The DNA-DNA relatedness between strain CJ7 T and Flavobacterium hercynium DSM 18292 T , which showed the highest 16S rRNA gene sequence similarity, was 25.4 %. The predominant cellular fatty acids were iso-C 15 : 0 (18.3 %), summed feature 3 (comprising iso-C 15 : 0 2-OH and/or C 16 : 1 v7c) (16.1 %), iso-C 17 : 0 3-OH (8.9 %), iso-C 15 : 0 3-OH (7.2 %), iso-C 17 : 1 v9c (6.1 %) and iso-C 15 : 1 (5.9 %). Flexirubin-type pigments were absent. The major isoprenoid quinone was menaquinone-6. The DNA G+C content was 34.5 mol%. The results obtained from this study, with a polyphasic taxonomic approach, suggested that strain CJ7 T represents a novel species of the genus Flavobacterium for which the name Flavobacterium chungangense sp. nov. is proposed. The type strain is CJ7 T (5KACC 13353 T 5JCM 15651 T ).The genus Flavobacterium is a diverse group of bacteria that are commonly found in soil, freshwater and fish tissues (Bernardet et al., 2002;Bernardet & Bowman, 2006) and contains over 60 recognized species. In this study, a Flavobacterium-like bacterium was isolated and examined using a polyphasic taxonomic approach. Thus, we report the description of a novel species of the genus Flavobacterium.A bacterial strain, designated CJ7 T , was isolated from a freshwater lake at Chung-Ang University in Anseong, South Korea (37 u 09 N 127 u 139 E). Isolation was carried out using the standard dilution plating method on R2A agar (Conda) at 30 u C. The isolate was routinely cultured on R2A agar and maintained at 280 u C as a suspension in R2A broth supplemented with glycerol (20 %, v/v).The 16S rRNA gene was amplified from a single colony by PCR using AccuPower PCR Premix (Bioneer) and primers 27F and 1492R (Lane, 1991). The PCR product was purified using the AccuPrep PCR Purification kit (Bioneer) and sequencing of the 16S rRNA gene was performed with an Applied Biosystems automatic sequencer (ABI 3730XL) at Macrogen (Seoul). Phylogenetic analysis including pairwise 16S rRNA gene sequence similarity comparisons was achieved using the EzTaxon server (http://www.eztaxon.org; Chun et al., 2007). Initial similarity analyses indicated that strain CJ7 T was closely related to members of the genus Flavobacterium. The nearly complete 16S rRNA gene sequence of strain CJ7 T (1335 bp) was aligned manually against those of representatives of the genus Flavobacterium using the bacterial 16S rRNA secondary structure model and the JPHYDIT program (Jeon et al., 2005). The phylogenetic analyses were performed by the neighbour-joining (Saitou & Nei, 1987), maximumlikelihood (Felsenstein, 1981 and ma...