Carbon nanocage: super-adsorber of intercalators for DNA protection

In this research, we report the binding behaviors of two kinds of intercalators, methyl violet and 3,6-diaminoacridine hydrochloride, to various mesoporous materials, carbon nanocage, mesoporous carbon CMK-3, activated carbon, and mesoporous silica SBA-15. Due to its unique cage type structure, carbon nanocage shows greater adsorption capacity than the other adsorbents. In addition, competitive adsorption of methyl violet between DNA and mesoporous materials confirmed that carbon nanocage can very efficiently inhibit intercalation of methyl violet by DNA. Carbon nanocage might then be useful for entrapment of harmful aromatic molecules.     

Large array of sub-10-nm single-grain Au nanodots for use in nanotechnology

A uniform array of single-grain Au nanodots, as small as 5-8 nm, can be formed on silicon using e-beam lithography. The as-fabricated nanodots are amorphous, and thermal annealing converts them to pure Au single crystals covered with a thin SiO(2) layer. These findings are based on physical measurements, such as atomic force microscopy (AFM), atomic-resolution scanning transmission electron microscopy, and chemical techniques using energy dispersive X-ray spectroscopy. A self-assembled organic monolayer is grafted on the nanodots and characterized chemically with nanometric lateral resolution. The extended uniform array of nanodots is used as a new test-bed for molecular electronic devices.     

Natural tubule clay template synthesis of silver nanorods for antibacterial composite coating

Halloysite is naturally available clay mineral with hollow cylindrical geometry and it is available in thousands of tons. Silver nanorods were synthesized inside the lumen of the halloysite by thermal decomposition of the silver acetate, which was loaded into halloysite from an aqueous solution by vacuum cycling. Images of individual ca. 15 nm diameter silver nanorods and nanoparticles were observed with TEM. The presence of silver inside the tubes was also verified with STEM-EDX elemental mapping. Nanorods had crystalline nature with [111] axis oriented ~68° from the halloysite tubule main axis. The composite of silver nanorods encased in clay tubes with the polymer paint was prepared, and the coating antimicrobial activity combined with tensile strength increase was demonstrated. Coating containing up 5% silver loaded halloysite did not change color after light exposure contrary to the sample prepared with loading with unshelled silver nanoparticles. Halloysite tube templates have a potential for scalable manufacturing of ceramic encapsulated metal nanorods for composite materials.     

Large area thin film Si module

An initial efficiency of 14.1% (J_sc=13.6 mA/cm², V_oc=1.392 V, FF=74.3%) has been achieved for a-Si/transparent interlayer/poly Si solar cell (total area of 1 cm²). Both a-Si and crystalline Si films were fabricated by plasma chemical deposition at low temperature. The short circuit current was enhanced by the introduction of a transparent intermediate layer. An initial aperture efficiency of 11.7% has been achieved for 910×455 mm² a-Si/poly Si integrated solar cell submodule, where the laser-scribing techniques were applied for series interconnections. The results of our first run of 266 submodules in our pilot plant showed the average efficiency of 11.2%, which is applicable for mass production.     

Effect of the Chevron Angle on Cooling Heat Transfer Characteristics of Supercritical Pressure Fluids in Plate Heat Exchangers

ABSTRACT

For the development of industrial heat pump systems supplying a high-temperature heat source over 130°C, the authors have studied on cooling heat transfer of supercritical pressure fluids flowing in chevron-type plate heat exchangers (PHEs). In this study, to examine the effect of chevron angle on cooling heat transfer of supercritical pressure refrigerants, experiments were conducted for HFC134a and HFO1234ze(E) flowing in the PHEs with the chevron angles from 30° to 65°. In the experiments, cooling heat transfer coefficients were obtained in the wide range of bulk fluid enthalpy from vapor-like high temperature to liquid-like low temperature, changing the pressure in the reduced pressure range from 1.01 to 1.2 at the mass flow rates of 7 and 11 kg/min. Especially for the enthalpy region of the pseudo critical point and its vicinity in which good heat transfer appeared, the effect of chevron angle on heat transfer of supercritical pressure fluids was clarified based on the measurements. Furthermore, the effect of chevron angle was examined for the wide angle range from 0° to 90° with estimating the heat transfer coefficient for the angles 0° and 90° from appropriate correlations. Besides, the present data were compared with some conventional heat transfer correlations.     

Real-time PCB monitoring using time-of-flight mass spectrometry with picosecond laser ionization

The study demonstrates the applicability of laser ionization time-of-flight mass spectrometry for real-time measurement of polychlorinated biphenyls (PCBs). Picosecond 266-nm laser light ionization reduced fragmentation and provided very high PCB detection sensitivity. This high sensitivity has advantages in terms of real-time monitoring capability as compared to the conventional GC-ECD or GC-MS methods, which require at least several days for the analysis of PCBs. Detection sensitivity of under 0.01 mg/Nm3 was achieved with a 1-min measuring time; this sensitivity is superior to the exhaust gas control guideline of 0.15 mg/Nm3 by a factor of 10. A prototype PCB monitoring device has been developed and tested in a pilot PCB treatment plant. The 1-min detection time represents a substantial advance in the monitoring of exhaust gas and the workplace atmosphere in accordance with safety regulations.     

Oral Administration of Bovine Milk from Cows Hyperimmunized with Intestinal Bacterin Stimulates Lamina Propria T Lymphocytes to Produce Th1-Biased Cytokines in Mice

The goal of this study was to examine the effects of oral administration of bovine milk from cows hyperimmunized with a proprietary bacterin (immune milk “Sustaina”) on mucosal immunity in the intestine of adult mice. C57BL/6 mice were orally given immune or control milk for two weeks, and then lymphocyte population and the cytokine production in lamina propria of colon in normal mice and mice induced colitis by dextran sulphate sodium (DSS) were detected. We found that the levels of IFN-γ and IL-10 increased, but the levels of IL-17A and IL-4, decreased in lamina propria of colon in immune milk-fed mice as compared with those in control milk-fed mice. Interestingly, oral administration of immune milk partially improved the acute colitis induced by DSS. The levels of TNF-α and IFN-γ increased, but IL-6, IL-17A and IL-4 decreased in lamina propria (LP) of colon in immune milk-fed mice with DSS-induced colitis. Our results suggest that immune milk may stimulate CD4⁺ T cells to polarize towards a Th1 type response, but contrarily suppress Th17 and Th2 cells responses in large intestinal LP of mice. The results indicate that this kind of immune milk has is able to promote the maintainance of intestinal homeostasis and enhance protection against infection, and could alleviate the symptoms of acute colitis in mice.     

Fine-tuning supramolecular assemblies of fullerenes bearing long alkyl chains

Fine-tuning of the supramolecularly organized nanometer scale architectures of fullerene derivatives, fulleropyrrolidines substituted with a mono-, di-, or tri(n-hexadecyloxy)phenyl group is described. These synthetic fullerene derivatives possess one- (1), two- (2), or three- (3) long alkyl chains. The correlation between the number of alkyl chain multiplicity and the self-organized bilayer structures as the fundamental subunit as well as the superstructures formed in different solvents were investigated using microscopic and spectroscopic techniques. The fullerene derivatives studied formed interdigitated lamellar bilayer structures whose d spacing values, estimated by X-ray diffraction patterns, are 2.63 nm for 1, 3.50 nm for 2, and 4.28 nm for 3, respectively. There are the two differing intermolecular forces present due to C₆₀ (sp²-carbons) or alkyl chains (sp³-carbons). Fullerene moieties always exhibit strong π-π interactions, while van der Waals interactions between alkyl chains can be altered by variation of their multiplicity. Substitution of three alkyl chains at the fullerene moiety (3) was the most effective method for stimulating polymorphism in its derivatives in different solvents.