The recetor sites for complement (C3) on human diploid fibroblasts

Sheep red cells, sensitized with 19S fraction of antiserum and subsequently treated with mouse serum as the source of complement (EAC), interact with human diploid fibroblasts (WI-38 cells) and form "Rosettes". Under a scanning electron microscope, EAC have not attached directly to the cell surface of fibroblasts, but to the fine processes or microvilli of the latter, as if there were fine bridges between EAC and the surface of fibroblasts. On the other hand, the attachment of sheep red cells washed in PBS (E) or sensitized with 19S fraction of antiserum (EA) to WI-38 cells was not observed. The pretreatment of WI-38 cells with mouse serum did not inhibit the interaction of WI-38 cells and EAC. No phagocytosis of EAC by WI-38 cells was observed in the 2 hrs incubation of both cells. From these results it is suspected that the interaction of WI-38 cells and EAC is immune adherence, and that WI-38 cells have the receptor site for complement, especially for C3, on the surface of cell membrane.     

Facet preferential growth of self-assembled InAs dots on patterned GaAs substrates

We have investigated the self-assembled InAs dot growth on patterned (100), (111)B, and (311)A GaAs substrates in order to obtain facet preferential characteristics among various facets for the purpose of better position control of the dots for possible applications to the electronic and photonic devices. The self-assembled InAs dots were found to grow selectively in the bottom of the tetrahedral etch-pits or on certain ridges or valleys or slopes of grooved surfaces in a regular fashion. Some common preference relationships among different original orientation of the substrate were consistent with each other. The physical origin of the preference is explained by the combination of difference in number of bonds on different surfaces and the accommodation of strains by surface misfit dislocations.     

Dehydration of 1,4-butanediol over supported rare earth oxide catalysts

Vapor-phase catalytic dehydration of 1,4-butanediol was investigated over rare earth oxides supported on ZrO₂. In the dehydration of 1,4-butanediol, 3-buten-1-ol was mainly produced, together with tetrahydrofuran (THF) and γ-butyrolactone. The heavy group of rare earth oxides, such as Dy₂O₃, Ho₂O₃, Er₂O₃, Tm₂O₃, Yb₂O₃, and Lu₂O₃, supported on monoclinic ZrO₂ showed higher selectivity to 3-buten-1-ol than pure monoclinic ZrO₂ and supported light rare earth oxides, such as La₂O₃ and Pr₆O₁₁. Supported Yb₂O₃ catalysts dispersed on other oxides, such as alumina, silica, and tetragonal ZrO₂ catalyze the formation of THF. X-ray diffraction (XRD) measurements reveal that cubic Yb₂O₃ crystallites dispersed on monoclinic ZrO₂ provide active sites in the dehydration of 1,4-butanediol to produce 3-buten-1-ol.     

Catalysis by Mesoporous Dendrimers

The present study reports the divergent synthesis, characterization and catalytic properties of different generation of triazine based aromatic amine dendritic mesoporous silicas derived via a stepwise functionalization of mesoporous silica substrates of different pore sizes with 2,4,6 tricholorotriazine and ethylene diamine. Mesoporous dendritic silicas up to second generation (2G) are grown in side the channels of mesoporous silica materials with 4 and 7 nm pore sizes. The catalytic properties of resulted dendritic materials in Knoevenagel condensation reaction were compared to the aliphatic polyamidoamine dendrimers that are also grown up to second generation (2G) inside the mesoporous channels. The reusability study of both aliphatic and aromatic dendritic mesoporous silica systems is also compared.     

Imaging Surface Immobilization Chemistry: Correlation with Cell Patterning on Non‐Adhesive Hydrogel Thin Films

High‐fidelity surface functional group (e.g., N‐hydroxysuccinimide (NHS) reactive ester) patterning is readily and reliably achieved on commercial poly(ethylene glycol) (PEG)‐based polymer films already known to exhibit high performance non‐fouling properties in full serum and in cell culture conditions. NHS coupling chemistry co‐patterned with methoxy‐capped PEG using photolithographic methods is directly spatially imaged using imaging time‐of‐flight secondary ion mass spectrometry (ToF‐SIMS) and principal components statistical analysis. Patterned NHS surface reactive zones are clearly resolved at high sensitivity despite the complexity of the polymer matrix chemistry. ToF‐SIMS imaging also reveals the presence of photo‐resist residue remaining from typical photolithography processing methods. High cross‐correlation between various ion‐derived ToF‐SIMS images is observed, providing sensitive chemical corroboration of pattern chemistry and biological reactivity in complex milieu. Surface‐specific protein coupling is observed first by site‐selective reaction of streptavidin with NHS patterns, followed by identical patterns of biotinylated Alexa‐labeled albumin coupling. This suggests that streptavidin immobilized on the patterns remains bioactive. Fluorescently labeled full serum is shown to react selectively with NHS‐reactive regions, with minimal signal from methoxy‐capped regions. Insufficient serum is adsorbed under any conditions to these surfaces to support cell attachment in serum‐containing media. This reflects the high intrinsic non‐adsorptive nature of this chemistry. Fibroblasts attach and proliferate in serum culture only when a cell adhesion peptide (RGD) is first grafted to NHS regions on the PEG‐based surfaces. Longer‐term serum‐based cell culture retains high cell‐pattern fidelity that correlates with chemical imaging of both the NHS and RGD patterns and also lack of cell adhesion to methoxy‐capped regions. Cell staining shows orientation of adherent cells within the narrow patterned areas. Cell patterns are consistently retained beyond 15 days in serum media.     

Analysis of trace residues of tetracyclines in dark-colored honeys by high-performance liquid chromatography using polymeric cartridge and metal chelate affinity chromatography

An efficient clean-up procedure was developed for the trace residue determination of tetracyclines (TCs) in dark-colored honeys. TCs were extracted from samples with McIlvaine buffer (pH 4.0) containing 0.01 mol/L Na(2)EDTA. The extracts were treated with both a polymeric cartridge (GL-Pak PLS-2) and a metal chelate affinity column (MCAC) preloaded with copper(II). TCs were eluted and analyzed by high-performance liquid chromatography (HPLC) using fluorescence detection. The method was evaluated for the determination of oxytetracycline (OTC), tetracycline (TC), and chlortetracycline (CTC) in buckwheat honey, because its color is the darkest. The mean recoveries of OTC, TC and CTC from spiked samples, at three fortification levels, were >70%, and the relative standard deviations (RSDs) were <10%. Limits of quantitation (LOQs) of OTC, TC, and CTC were estimated to be 0.015 mg/kg, 0.019 mg/kg, and 0.024 mg/kg, respectively.     

D-allose protects against endotoxemic acute renal injury

D-allose is a monosaccharide. We previously reported that D-allose attenuated renal injury by inhibiting the activation of neutrophils after renal ischemia/reperfusion. Lipopolysaccharide (LPS) triggers sepsis syndrome by activating monocytes to produce proinflammatory cytokines, including tumor necrosis factor (TNF)-alpha, which potently stimulates the activation of neutrophils. This study was undertaken to examine the effects of D-allose on renal injury in the systemic inflammatory response induced by LPS administration, with emphasis on systemic TNF-alpha and the activation of neutrophils in the rat kidney. Serum and renal TNF-alpha, renal cytokine-induced neutrophil chemoattractant (CINC)-1, and myeloperoxidase (MPO) concentrations, and renal function after LPS administration were evaluated. D-allose (400 mg/kg body weight) inhibited LPS-induced increases in serum and renal TNF-alpha concentrations and renal CINC-1 and MPO concentrations after LPS administration, as well as the subsequent neutrophil-mediated renal injury. These findings may have important implications in understanding the biologic functions of D-allose. D-allose may prove useful in protecting against acute renal injury in systemic inflammatory responses to LPS.     

Near-infrared finger vein patterns for personal identification

We have demonstrated a personal identification system that is based on near-infrared finger vein patterns. Finger vein patterns of 678 volunteers are acquired by transmitting near-infrared light through a finger and capturing the image with a CCD camera. These vein patterns are enhanced by a background-reduction filter. The similarity between two patterns is then quantified by use of the normalized maximum of the cross correlation of the two images after correction of the tilt angle. The enhanced finger vein pattern enabled 678 persons to be successfully identified.     

High-coupling-efficient 1.3-μm laser diodes with goodtemperature characteristics

We have proposed uniformly beam-expanded structures based on the advanced concept for realizing high coupling efficiency and good temperature characteristics. Beam expansion (optical confinement reduction) by narrowing the core layer width as well as a carrier confinement are strongly enhanced by adopting a larger bandgap InGaAsP for MQW barriers and separate confinement heterostructure layers. These laser diodes (LD's) were fabricated by the conventional buried heterostructure laser process, which is very important in reducing the cost. Our results have proven the effectiveness of our proposition. The LD's with high coupling efficiency (-3.2 dB) and good temperature characteristics have been achieved even using the simple approach of reducing optical confinement. The threshold currents at 25 and 85°C are 9.3 and 39.4 mA, respectively. The slope efficiency at 25°C is 0.39 W/A and still high (0.26 W/A) even at 85°C     

Phase equilibria of quasi-ternary systems consisting of multicomponent polymers 1 and 2 in a single solvent. II. Cloud point curve

Theoretical equations and a calculation method giving cloud point curve (CPC) for a multicomponent polymer 1/multicomponent polymer 2/single solvent system (i.e. quasi-ternary system) were derived on the basis of the Flory-Huggins solution theory. The systematic calculations based on this method were carried out to examine the effects on CPC of the type of molecular weight distribution, the polydispersity and the weight-average degree of polymerisation of the two original polymers, and three thermodynamic interaction parameters between solvent-polymer 1 (X₀₁), solvent-polymer 2 (X₀₂) and polymer 1-polymer 2 (X₁₂). The shape of CPC sensitively depends on the polydispersity of the original polymer and, with an increase in polydispersity, the immiscibility region becomes wider.