Copper‐ion adsorption and gold‐ion reduction by polyphenols prepared by the enzymatic reaction of horseradish peroxidase

Polyphenols were synthesized via a horseradish peroxidase reaction from phenol, catechol, and pyrogallol for use as copper‐ion adsorbents. The molecular weights of the polyphenols ranged from about 1000 to 3000 g/mol. The hydroxyl group contents in the polyphenols from phenol, catechol, and pyrogallol were 5.9, 4.0, and 0.94 mol/kg, respectively, as determined by titration. The saturation binding capacity for copper ions of the polyphenols from phenol, catechol, and pyrogallol were calculated to be 1.44, 0.88, and 0.22 mol/kg, respectively, at pH 4.5. Copper ions were efficiently adsorbed via an ion‐exchange interaction by the synthesized polyphenols with vicinal hydroxyl groups, and those polyphenols could be applied to metal adsorption. Gold ions were selectively reduced by the phenol group in polypyrogallol in acid media to form gold particles. The reduced gold particles were eluted with a solution of 1.0M thiourea plus 0.5M HCl. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Gamma-ray and neutron dosimetry by EPR and AMS, using tooth enamel from atomic-bomb survivors: a mini review

The electron paramagnetic resonance (EPR, or electron spin resonance) method was used to measure CO??· radicals recorded in tooth enamel by exposure to atomic-bomb gamma rays. The EPR-estimated doses (i.e. ??Co gamma-ray equivalent dose) were generally in good correlation with cytogenetic data of the same survivors, whereas plots of EPR-estimated dose or cytogenetically estimated dose against DS02 doses turned out to scatter more widely. Because those survivors whose EPR doses were higher (or lower) than DS02 doses tended to show also higher (or lower) responses for cytogenetic responses, the apparent variation appears primarily due to problems in individual DS02 doses rather than the measurement errors associated with the EPR or cytogenetic technique. A part of the enamel samples were also used for evaluation of neutron doses by measuring ?1Ca/??Ca ratios using the accelerator mass spectrometry technique. The results for the measured ratios were on average ~85 % of the calculated ratios by DS02 (but within the 95 % confidence bounds of the simulated results), which lends support to DS02-derived neutron doses to the survivors.     

Thermoplastic Acrylic Rubber Physically Crosslinked by Tiny Poly(vinylidene fluoride) Crystals

Summary: Acrylic rubber showed greatly improved mechanical properties and very nice elasticity when blended with small amount of PVDF. PVDF crystallized into very sparse and loose spherulites in the blends with ACM molecular chains incorporated into the PVDF lamellae. These micro‐crystals were precisely dispersed in the ACM matrix and acted as the physical crosslink points for the matrix upon stretching. Therefore, the ACM/PVDF blends containing small amounts of PVDF display the typical properties of thermoplastic elastomers with large elongation at break, high tensile strength, and excellent strain recovery from the highly deformed state.

Schematic diagram of physically crosslinked ACM by the tiny PVDF crystals in ACM‐rich PVDF/ACM blends.     

Analyses of homo-oligomer interfaces of proteins from the complementarity of molecular surface, electrostatic potential and hydrophobicity

To extract the general structural features of interacting protein pairs, the non-redundant homo-oligomer interfaces (393 interfaces) in the PDB were analyzed using the fine-grained molecular surface, electrostatic potentials and the hydrophobicity calculated as the solvation free energy using empirical parameters. For each property, statistical analyses of the degree of complementarity were carried out, and we developed a method to judge whether interfaces were shape-complementary, electrostatic-complementary and/or hydrophobic-complementary or not. In order to search for the correlation between the property complementarity and structure of the interfaces, at first, we roughly classified all the interfaces into the following five groups according to the structure of the interface and surveyed the correlation between the shape classification and the complementary: cyclic-oligomer (69), twisted-dimer (27), dimer-parallel (14), dimer-perpendicular (109) and dimer-circular (174), where the number in the parenthesis is the number of interfaces in each group. As a result, we found the new characteristic trends as the possible necessary conditions in the formation of homo-oligomer interfaces, especially from the viewpoint of electrostatic complementarity. In addition, we also show that complementarity analyses can be used to discriminate the biological-interface from the crystallographic-interface in homo-oligomer proteins.     

Fabrication of Microporous Films Utilizing Amphiphilic Block Copolymers and Their Use as Templates in Poly(aniline) Preparation

Summary Ordered microporous films were fabricated on the process of solvent evaporation for the solution of amphiphilic poly(acrylic acid)-block-polystyrene under a humid atmosphere. Pore size and its distribution are strongly dependent on the nature of polymers and the evaporation conditions. Poly(aniline) dots were also successfully fabricated via electropolymerization of aniline using a microporous film on indium tin oxide electrode as a template.     

A possible role for p16INK4 in neuronal cell death after retinal ischemia-reperfusion injury

PURPOSE: To study whether cell type-specific death occurs in retinal ischemia-reperfusion injury and the possible roles of p16INK4 in the determination of cell death. METHODS: Retinal ischemia-reperfusion injury was induced in rats by a ligation method. After 1 hour of ischemia and a time of reperfusion that varied, rat eyes were enucleated. Cell death in the retina was studied by the TdT-dUTP terminal nick-end labeling method and propidium iodide (PI) staining. Electron microscopic observation of the retina was also performed. Immunohistochemical studies using antibodies against syntaxin and calbindin were performed to detect amacrine cells and horizontal cells, respectively, and immunohistochemical studies using an antibody against p16INK4 were performed to study whether this cell cycle-related protein was expressed in dying cells. RESULTS: Most of the calbindin-positive horizontal cells in the outer aspect of the inner nuclear layer (INL) showed morphologic features of necrosis. In contrast, syntaxin-positive amacrine cells in the inner aspect of the INL showed features of apoptosis. Of 320 calbindin-positive horizontal cells, only 11 (3.4%) showed positive PI staining. Those calbindin-positive, horizontal cells were p16INK4 positive. In contrast, 746 of 910 (82.0%) syntaxin-positive amacrine cells showed condensed PI staining, and none were p16INK4 positive. CONCLUSIONS: Expression of p16INK4 may regulate the fate of retinal neurons in ischemia-reperfusion injury, and cell type-specific death thus occurs in the retina after such injury.     

Production and characterization of a monoclonal antibody against recombinant thermolabile hemolysin and its application to screen for Vibrio parahaemolyticus contamination in raw seafood

Thermolabile hemolysin gene (tlh) is regarded as a species-specific marker for Vibrio parahaemolyticus. To assess the utility of the tlh gene product, thermolabile hemolysin (TLH), as a marker to screen for V. parahaemolyticus-contamination in raw seafood, we generated a monoclonal antibody (MAb) against recombinant TLH and established with an enzyme-linked immunosorbent assay using the MAb (TLH-ELISA). TLH-ELISA testing of broth cultures for 78 V. parahaemolyticus strains showed positive results all around. In contrast, most broth cultures of 53 non-V. parahaemolyticus species tested yielded negative results.We devised a screening method using TLH-ELISA to check for low-level contamination of V. parahaemolyticus in raw seafood within 24 h and evaluated its ability. In testing of V. parahaemolyticus-spiked raw seafood, results suggested that our screening method can detect 100 most-probable-number (MPN) of V. parahaemolyticus/g. Further, on testing 119 commercial raw seafood samples with our screening method, 117 samples were determined to contain less than 100 MPN of V. parahaemolyticus/g. All of the 117 samples were also estimated by the MPN method to contain less than 100 MPN of V. parahaemolyticus/g. Taken together, these results suggest that our screening method using TLH-ELISA is useful to check for low-level (<100 MPN/g) of V. parahaemolyticus in raw seafood.     

Addition of Aliskiren to Angiotensin Receptor Blocker Improves Ambulatory Blood Pressure Profile and Cardiorenal Function Better than Addition of Benazepril in Chronic Kidney Disease

An altered ambulatory blood pressure (BP) and heart rate (HR) profile is related to chronic kidney disease (CKD) and cardiorenal syndrome. In this study, we examined the effects of aliskiren, when added to angiotensin II type 1 receptor blockers, on ambulatory BP and cardiorenal function in CKD. Thirty-six hypertensive CKD patients were randomly assigned to the aliskiren add-on group (n = 18) or the benazepril add-on group (n = 18). Ambulatory BP and cardiorenal function parameters were measured at baseline and 24 weeks after treatment. Compared with the benazepril group, nighttime systolic BP variability in the aliskiren group was lower after treatment. Albuminuria was decreased in the aliskiren group, but not in the benazepril group. In addition, left ventricular mass index (LVMI) was significantly lower in the aliskiren group than in the benazepril group after treatment. In the aliskiren group, multivariate linear regression analysis showed an association between changes in albuminuria and changes in nighttime systolic BP. Furthermore, there were associations between changes in LVMI and changes in daytime HR variability, as well as between changes in LVMI and changes in plasma aldosterone concentration. These results suggest that aliskiren add-on therapy may be beneficial for suppression of renal deterioration and pathological cardiac remodeling through an improvement that is effected in ambulatory BP and HR profiles.