Direct deposition of two nanomaterials with the same surface charge using a liquid-liquid interface

Two negatively charged nanoparticles (SDS-coated SWCNT and polydiacetylene nanocrystals) were sequentially adsorbed onto the same water-hexane interface. The absorbed film can be transferred onto a solid substrate. Repeating the adsorption and transfer process enables assembly of the two nanoparticles in a layer-by-layer growth fashion up to three bi-layers.     

Association of ceramides in human plasma with risk factors of atherosclerosis

Atherosclerosis is a multifactorial disorder. Recent studies indicate that the plasma level of sphingomyelin, which yields ceramide, correlates with the risk of coronary heart disease. Therefore, ceramide, a well-known lipid causing apoptosis in various cell types, may contribute to atherogenesis. We examined the relationship between ceramide concentration and risk factors of atherosclerosis in normal human plasma using electrospray tandem mass spectrometry (LC-MS/MS). Major ceramides in human plasma were C24∶0 and C24∶1. The ceramide concentration showed a significant positive correlation with total cholesterol (TC) and triglycerides (TG). In addition, plasma ceramide level increased drastically at a high level of LDL cholesterol (more than 170 mg/dL). Our previous studies demonstrated that the sum of fragmented and conjugated apolipoprotein B-100 proteins (B-ox), which were products of a radical reaction of LDL as well as plasma, was a reliable index of atherosclerosis. B-ox showed a significant positive correlation with the plasma ceramide level. Based on these results, we propose that the ceramide level in human plasma is a risk factor at the early stages of atherosclerosis.     

Synthesis and biological evaluation of boronic acid containing cis-stilbenes as apoptotic tubulin polymerization inhibitors

A series of boronic acid containing cis-stilbenes as potent inhibitors of tubulin polymerization was synthesized by the introduction of boronic acid as an acceptor-type functional group into the aromatic ring B of the combretastatin framework. High cell-growth inhibition was observed with boron compounds 13 c and 13 d, in which a hydroxy group on the aromatic ring B of combretastatin A-4 was replaced with boronic acid; IC50 values toward B-16 and 1-87 cell lines are 0.48-2.1 microM. Compounds 13 c and 13 d exhibited significant inhibitory activity toward tubulin polymerization (IC50=21-22 microM). The carboxylic acid derivative 17, which can be considered as a mimic of boronic acid 13 c, did not show significant inhibition of cell growth or tubulin polymerization. According to the FACScan analysis using Jurkat cells, apoptosis was induced after incubation for 8 h with 13 c at a concentration of >10(-8) M. Growth inhibitory experiments against a panel of 39 human cancer cell lines revealed 13 c to inhibit growth differently than combretastatin A-4; the correlation coefficient (r) between the two compounds was 0.553 in the COMPARE analysis.     

Example of examination of allergic substances (egg, milk) in commercial foods

Allergic substances (eggs, milk) in commercial foods were measured by means of the notified ELISA methods using FASTKIT ELISA kit (N kit) and "Tokuteigenzairyo sokutei kit" (M kit). Some samples were also analyzed with the notified western blot method using "Tokuteigenzairyo western blot kit". In the methods for detection of eggs, proteins of fish egg and chicken muscle were examined using the ELISA and Western blotting methods to check for cross-reaction. Sujiko was false positive with the M kit. Difficulties were also encountered in the notified ELISA and Western blotting methods with raw chicken. In foods labeled as containing eggs, it was difficult to detected in the heart-processed food using both notified methods. In the method for detection of milk, foods containing thickening polysaccharides, showed cross-reaction with the N kit. However, this cross-reaction was eliminated when an improved N kit was used. Foods labeled as containing milk did not present any difficulty.     

Local crystal structure analysis with several picometer precision using scanning transmission electron microscopy

We report a local crystal structure analysis with a high precision of several picometers on the basis of scanning transmission electron microscopy (STEM). Advanced annular dark-field (ADF) imaging has been demonstrated using software-based experimental and data-processing techniques, such as the improvement of signal-to-noise ratio, the reduction of image distortion, the quantification of experimental parameters (e.g., thickness and defocus) and the resolution enhancement by maximum-entropy deconvolution. The accuracy in the atom position measurement depends on the validity of the incoherent imaging approximation, in which an ADF image is described as the convolution between the incident probe profile and scattering objects. Although the qualitative interpretation of ADF image contrast is possible for a wide range of specimen thicknesses, the direct observation of a crystal structure with deep-sub-angstrom accuracy requires a thin specimen (e.g., 10 nm), as well as observation of the structure image by conventional high-resolution transmission electron microscopy.     

Study of the nanoscopic deformation of an annealed nafion film by using atomic force microscopy and a patterned substrate

We demonstrated the repetitive imaging of the same area of a nafion film before and after annealing by using atomic force microscopy (AFM). In order to find the exact same area of the same sample after changing the cantilever and reattaching the sample, a micropatterned substrate was developed. A micropattern with a 250–500 μm pitch was prepared on the backside of a transparent glass substrate. This pattern includes various signs such as colored letters and numbers at the center of each lattice of the pattern. The nanostructures fabricated by AFM nanolithography on a nafion film using this new method were successfully characterized before and after annealing (over 100 °C). The AFM images clearly showed that the nanostructures on a nafion film were dramatically changed by annealing. The data indicated an evidence to understand why the nafion fuel cell does not work well at high temperatures. Our method is probably effective for the study of nanoscopic dynamics in various surface structures.     

Fabrication of an hermetically packaged silicon resonator on LTCC substrate

The design, fabrication and packaging process of silicon resonators capable of the integration of LSI (Large Scale Integration) have been developed on the basis of packaging technology using an LTCC (Low Temperature Co-fired Ceramic) substrate. The structures of silicon resonators are defined by deep reactive ion etching (DRIE) on a silicon on insulator (SOI) wafer and then transferred onto the LTCC substrate and hermetically sealed by anodic bonding technique. The measured resonant frequency of a micromechanical bulk acoustic mode silicon resonator after packaging at 0.02 Pa is 20.24 MHz with a quality factor of 50,600.     

Numerical models of HDR geothermal reservoirs—a review of current thinking and progress

A brief review is presented of modelling and simulation of HDR geothermal reservoirs both for hydraulic fracturing/stimulation to create artificial/engineered geothermal reservoirs and for long-term heat extraction operations. Firstly, modelling of the governing factors is surveyed and coupling among mechanical, thermal, hydraulic and chemical effects is discussed. Next the structure and modelling of reservoirs are discussed. Finally, the features of a variety of simulation codes are summarized.     

Regulation of Polyunsaturated Fatty Acid Biosynthesis by Seaweed Fucoxanthin and Its Metabolite in Cultured Hepatocytes

The effects of a seaweed carotenoid, fucoxanthin, and its physiological metabolite, fucoxanthinol, on the biosynthesis of polyunsaturated fatty acids (PUFA) were investigated using cultured rat hepatoma BRL‐3A. The metabolism of α‐linolenic acid (18:3n‐3) was suppressed by the addition of these carotenoids, resulting in a decrease in the content of eicosapentaenoic acid (20:5n‐3), which suggested a down‐regulation of metabolic enzymes such as fatty acid desaturase and elongase. An increase in the content of docosahexaenoic acid (22:6n‐3), as observed in previous studies in vivo, might be a buffering action to maintain the membrane fluidity. The suppressive effect of fucoxanthinol on ?6 fatty acid desaturase was not at the level of gene expression but due to specific modifications of the protein via a ubiquitin–proteasome system. A proteomic analysis revealed several factors such as phosphatidylethanolamine‐binding protein that might be involved in the observed action of fucoxanthin. These findings will contribute to studies on the elucidation of the precise molecular mechanisms underlying the regulation of PUFA biosynthesis by fucoxanthin.