Evaluation of the Anti-Proliferative Activity of Rare Aldohexoses against MOLT-4F and DU-145 Human Cancer Cell Line and Structure-Activity Relationship of D-Idose

D-Allose (D-All), a C-3 epimer of D-glucose (D-Glc), is a naturally rare monosaccharide, which shows anti-proliferative activity against several human cancer cell lines. Unlike conventional anticancer drugs, D-All targets glucose metabolism and is non-toxic to normal cells. Therefore, it has attracted attention as a unique “seed” compound for anticancer agents. However, the anti-proliferative activities of the other rare aldohexoses have not been examined yet. In this study, we evaluated the anti-proliferative activity of rare aldohexoses against human leukemia MOLT-4F and human prostate cancer DU-145 cell lines. We found that D-All and D-idose (D-Ido) at 5 mM inhibited cell proliferation of MOLT-4F cells by 46 % and 60 %, respectively. On the other hand, the rare aldohexoses at 5 mM did not show specific anti-proliferative activity against DU-145 cells. To explore the structure–activity relationship of D-Ido, we evaluated the anti-proliferative activity of D-sorbose (D-Sor), 6-deoxy-D-Ido, and L-xylose (L-Xyl) against MOLT-4F cells and found that D-Sor, 6-deoxy-D-Ido, and L-Xyl showed no inhibitory activity at 5 mM, suggesting that the aldose structure and the C-6 hydroxy group of D-Ido are important for its activity. Cellular glucose uptake assay and western blotting analysis of thioredoxin-interacting protein (TXNIP) expression suggested that the anti-proliferative activity of D-Ido is induced by inhibition of glucose uptake via TXNIP-independent pathway.     

The Function of Sialidase Revealed by Sialidase Activity Imaging Probe

Sialidase cleaves sialic acid residues from glycans such as glycoproteins and glycolipids. In the brain, desorption of the sialic acid by sialidase is essential for synaptic plasticity, learning and memory and synaptic transmission. BTP3-Neu5Ac has been developed for sensitive imaging of sialidase enzyme activity in mammalian tissues. Sialidase activity in the rat hippocampus detected with BTP3-Neu5Ac increases rapidly by neuronal depolarization. It is presumed that an increased sialidase activity in conjunction with neural excitation is involved in the formation of the neural circuit for memory. Since sialidase inhibits the exocytosis of the excitatory neurotransmitter glutamate, the increased sialidase activity by neural excitation might play a role in the negative feedback mechanism against the glutamate release. Mammalian tissues other than the brain have also been stained with BTP3-Neu5Ac. On the basis of information on the sialidase activity imaging in the pancreas, it was found that sialidase inhibitor can be used as an anti-diabetic drug that can avoid hypoglycemia, a serious side effect of insulin secretagogues. In this review, we discuss the role of sialidase in the brain as well as in the pancreas and skin, as revealed by using a sialidase activity imaging probe. We also present the detection of influenza virus with BTP3-Neu5Ac and modification of BTP3-Neu5Ac.     

Preparation and biological evaluation of hydroxyapatite-coated nickel-free high-nitrogen stainless steel

Calcium phosphate was formed on nickel-free high-nitrogen stainless steel (HNS) by chemical solution deposition. The calcium phosphate deposition was enhanced by glutamic acid covalently immobilized on the surface of HNS with trisuccinimidyl citrate as a linker. X-ray diffraction patterns and Fourier transform infrared spectra showed that the material deposited on glutamic acid-immobilized HNS within 24 h was low-crystallinity calcium-deficient carbonate-containing hydroxyapatite (HAp). The biological activity of the resulting HAp-coated HNS was investigated by using a human osteoblast-like MG-63 cell culture. The HAp-coated HNS stimulated the alkaline-phosphate activity of the MG-63 culture after 7 days. Therefore, HAp-coated HNS is suitable for orthopedic devices and soft tissue adhesion materials.     

Selective adsorption of organic sulfur in coal extract by using metal-loaded carbon

The objective of this study was to develop an efficient cleaning process for hydrocarbon resources. We investigated the removal of organic sulfur from coal extract by using metal-loaded carbons. Tetralin and tetralin/phenol mixture were used for thermal extraction of Illinois No. 6 coal at 375 °C with a holding time of 1 h, and we examined the effects of temperature on product yield and sulfur-removal behavior using metal-loaded carbons. A decrease in the n-hexane insoluble fraction was observed at a temperature range from 200 °C to 250 °C in the extracts of tetralin and tetralin/phenol mixture. The organic sulfur content in the n-hexane insoluble fraction drastically decreased with increasing temperature. The organic sulfur in the n-hexane insoluble fraction was reduced above 200 °C, while the sulfur content reached 30-35% at 375 °C for both tetralin and tetralin/phenol mixture extracts. We investigated the effect of holding time on the extent of the coal extract desulfurization using Ni-loaded carbon. The sulfur content in the coal extract decreased as the holding time increased. The rate of coal extract desulfurization using tetralin/phenol was slower than that obtained using tetralin. The coal extract obtained using the tetralin/phenol mixture contained a heavier polar fraction, which may have impeded the adsorption. All organic sulfur in the coal extract could be successfully removed Ni-loaded carbon at a treatment temperature of 350 °C and a holding time of 8 h. No appreciable changes were observed in the content of carbon, hydrogen, or nitrogen at any temperature or holding time in the ultimate analysis of the n-hexane insoluble fraction treated with Ni-loaded carbon. The results demonstrated that Ni-loaded carbon was much effective in removing organic sulfurs from the coal extract.     

Structural phase transitions of methane+ethane mixed-gas hydrate induced by 1,1-dimethylcyclohexane

Methane+ethane+1,1-dimethylcyclohexane+water system was investigated by using Raman spectroscopy and isothermal phase equilibrium measurements under four-phase (gas+aqueous+large guest species+hydrate phases) equilibrium conditions at 288.15 K. The results suggest that three kinds of hydrate structures emerge at 288.15 K in the methane+ethane+1,1-dimethylcyclohexane+water system. The hydrate structure for this system changed from structure-H to structure-I via structure-II with increase in the mole ratio of ethane to methane.     

Laser manipulation of micro untransmissive particles in water

The laser trapping of untransmissive particles are discussed in this paper. Photon can generate the momentum to the untransmissive particle by diffraction and reflection on the surface of the particles. We tried laser trapping of untransmissive particles using an attractive force caused by the diffraction and radiation force caused by reflection. The laser trapping system includes CW YAG laser, which has 1.064 μm in wave length and an optical microscope. The motions of particles were monitored by a CCD camera on the top of the microscope and recorded by PC connected to the CCD camera.     

High-efficiency Cu(In,Ga)Se2 thin-film solar cells with a novel In(OH)3:Zn buffer layer

We propose the inclusion of a novel In(OH)₃:Zn²⁺ buffer layer for fabricating high-efficiency CIGS solar cells. This buffer layer was deposited using a solution consisting of ZnCl₂, InCl₃·4H₂O, and thiourea. The In(OH)₃:Zn²⁺ films showed high resistivities of 2.1×10⁸ Ω cm and transmittance of above 95% in the visible range. We expected two effects due to this new buffer layer: first is the formation of a passivation layer on the CIGS surface and the second is Zn-doping into CIGS layer, resulting in the formation of a buried junction. A cell efficiency of 14.0% (V_oc: 0.575 V, J_sc: 32.1 mA/cm², FF: 0.758) was achieved by using an In(OH)₃:Zn²⁺ buffer layer, without the light soaking effect.     

Quantitative determination of corrosion products and adsorbed water on copper in humid air containing SO2 by IR-RAS measurements

The time dependency of the amounts of corrosion products and co-existing adsorbed water on copper in humid air containing SO₂ was estimated from a series of in situ time-resolved IR-RAS spectra on the basis of the relations between the band intensities and the mass changes of the corrosion products, which were determined by simultaneous measurement of IR-RAS and QCM. The amounts of both corrosion products increased slowly at the initial stage and later increased rapidly. Although the relative humidity was kept constant, the amount of adsorbed water increased nearly the same behavior as that of corrosion products in the stage of relatively small amounts of corrosion products and later increased rapidly when the amounts of corrosion products increased. In humid air without SO₂, sulfite gradually decomposed and some of it changed into sulfate.     

Thermal and mechanical properties of a poly(ϵ‐caprolactone)/graphite oxide composite

The effect of graphite oxide (GO) as the enforcing filler on the properties of poly(?‐caprolactone) (PCL) was investigated in this study. Through the introduction of GO, the Young's modulus of PCL was increased from 340 to 1000 MPa, and the tensile strength of PCL was increased from 15 to 26 MPa. Furthermore, the interlayer distance of GO (0.6 nm) was found to expand to 1.1 nm in the PCL/GO composite, which indicated the intercalation of the PCL chain into the GO layers. Because of this intercalation structure of the PCL/GO composite, GO showed a higher reinforcing effect than graphite on the mechanical properties of PCL. The intercalation should have enabled much effective load transfer in the PCL/GO composites. Moreover, GO showed a nucleating effect toward the crystallization of PCL, as the nonisothermal crystallization peak temperature shifted from 25°C for pure PCL to about 34°C for the PCL/GO composites. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008