IR and XPS Studies on the Surface Structure of Poled ZnO–TeO2 Glasses with Second-Order Nonlinearity

The effect of thermal/electrical poling on the surface structure of 30ZnO·70TeO₂ glass has been investigated by means of IR reflectance and X-ray photoelectron spectroscopy (XPS). All the poled glasses exhibit a common characteristic that the second-order nonlinearity is induced preferentially in an anode-side surface region. The reflectance from the anode-side glass surface at around 635 cm^{− 1} assignable to the vibrational mode of the Te–O_ax bond, where ax stands for the axial position of the TeO₄ trigonal bipyramid, is smaller in comparison with both as-annealed and cathode-side surfaces. The XPS analysis of the anode-side surface shows a depletion of Zn²⁺ ions and penetration of Na⁺ ions from the borosilicate glass which was placed between the sample and the anode during poling. These results suggest that the poling brings about both the breaking of the tellurite glass network and compositional changes at the anode-side surface below which the second-order nonlinearity is preferentially induced.     

Thermoresponsive core–shell nanoparticles with cross-linked π-conjugate core based on amphiphilic block copolymers by RAFT polymerization and palladium-catalyzed coupling reactions

Well-defined amphiphilic block copolymers composed of S-vinyl sulfides and N-isopropyl acrylamide (NIPAM) were synthesized by reversible addition–fragmentation chain transfer (RAFT) polymerization. Thermoresponsive core–shell nanoparticles with cross-linked π-conjugate cores were obtained by in situ cross-linking reactions between 4-bromophenyl moieties in the block copolymers and diboronic acids or a diamine compound in the presence of a palladium catalyst following micelle formation in ethanol/H₂O or ethanol. We initially investigated RAFT polymerization of two S-vinyl sulfide derivatives, namely phenyl vinyl sulfide (PVS) and 4-bromophenyl vinyl sulfide (BPVS), using a dithiocarbamate-type chain transfer agent (CTA). Then, RAFT polymerization of NIPAM using poly(S-vinyl sulfide) macro-CTAs was conducted to synthesize the amphiphilic block copolymers. Suzuki and Buchwald-Hartwig coupling reactions were found to be effective in the preparation of core–shell nanoparticles with thermoresponsive shells and cross-linked optoelectronic cores. The resulting nanoparticles showed characteristic thermoresponsive properties, as confirmed by turbidity and dynamic light scattering measurements. Stable and uniform core cross-linked nanoparticles were successfully prepared by the in situ palladium-catalyzed coupling reactions, and the optoelectronic and thermoresponsive properties of the nanoparticles could be tuned depending on the nature of the difunctional coupling agents, reaction conditions, and comonomer composition of the block copolymers.     

Microwave-assisted dechlorination of polychlorobenzenes by hypophosphite anions in aqueous alkaline media in the presence of Pd-loaded active carbon

Microwave-assisted dechlorination of chlorobenzene and the three dichlorobenzenes takes place in the presence of the hypophosphite (NaH(2)PO(2)) reductant and Pd-loaded activated carbon (Pd/C) in alkaline media at relatively low temperatures. The extent of loss/dechlorination at 90 degrees C followed the order: o-DCB approximately m-DCB>CB>p-DCB. Detected final products were mostly benzene and phenol. Dechlorination of pentachlorobenzene (PeCB) through reduction was slight even when both NaH(2)PO(2) and Pd/C were simultaneously employed in the absence of NaOH, nor when NaH(2)PO(2) alone was present in excess. The generated HCl proved to be an inhibitor, thus the need for the presence of NaOH to enhance dechlorination. Conventional heating of the reacting mixture above 90 degrees C to a reaction temperature of 180 degrees C led to no further dechlorination of the PeCB. Intermediate products of dechlorination of PeCP were the tetrachlorobenzenes with final products being benzene and phenol (GC-FID spectral analyses). Both salicylic acid (a constituent of humic acid) and l(+)-ascorbic acid used as possible promoters proved to be rather ineffective. The simultaneous presence of NaH(2)PO(2), Pd-loaded activated carbon and NaOH was crucial in the dechlorination of PeCB by microwave dielectric heating with maximal reduction of PeCB being ca. 75% under these conditions.     

Effect of pore size of self-organized honeycomb-patterned polymer films on spreading, focal adhesion, proliferation, and function of endothelial cells

The design of nano- and microstructures based on self-organization is a key area of research in the search for new materials, and it has a variety of potential applications in tissue engineering scaffolds. We have reported a honeycomb-patterned polymer film (honeycomb film) with highly regular pores that is formed by self-organization. This study describes the behavior of vascular endothelial cells (ECs) on honeycomb films with four different pore sizes (5, 9, 12, and 16 microm) as well as on a flat film. We examined the influence of the honeycomb pattern and pore size on cell behavior. The changes in cell morphologies, actin filaments, vinculin clusters, cell proliferation, and secreted extracellular matrix (ECM) (fibronectin, laminin, type IV collagen, and elastin) production profiles were observed by using optical, fluorescence, and scanning electron microscopy. The ECs that adhered to the flat film showed an elongated morphology with random orientation; the actin filaments and focal adhesions were not conspicuous. On the other hand, the ECs on the honeycomb films exhibited greater spreading and flattening; the degree of spreading of the ECs increased with an increase in the pore size. The actin filaments and focal adhesions appeared conspicuous, and the focal adhesions localized along the edge of the honeycomb pores were distributed over the entire projected cell area. The honeycomb film with a pore size of 5 microm showed the highest cell proliferation and ECM production profiles. These results suggest that the honeycomb film is a suitable material for designing a new vascular device.     

Role of phosphatidylinositol 3-phosphate in formation of forespore membrane in Schizosaccharomyces pombe

Phosphatidylinositol (PI) 3-kinase (encoded by the pik3(+) gene) in Schizosaccharomyces pombe has been identified as a homologue of VPS34p, a protein required for proper vesicular protein sorting. The clone defective in this protein carries enlarged vacuoles and exhibits sensitivity to high temperature or high ion concentration. The effect of disruption of pik3(+) on sporulation of Sz. pombe was examined. The diploid cells underwent G(1) arrest and meiosis. However, the spores formed by the deltapik3 cells were not viable. Electron-microscopic analysis revealed that the growth of the forespore membrane of deltapik3 cells was not correctly orientated, failing to engulf the nucleus or forming extremely small spores, as was confirmed by the use of Spo3p-GFP and GFP-Psy1p, which are markers of the forespore membrane. The coating materials found along the forespore membrane of the wild-type were greatly reduced in these cells. PI 3-P, the product of Pik3p, was detected on the forespore membrane, suggesting that PI 3-P-dependent vesicle transport may take place in formation of the forespore membrane. Misshaped forespore membrane, accumulation of vesicles, formation of small non-viable spores, and suppression by over expression of Psy1p were the phenotypes commonly seen in deltapik3 and deltaspo3 cells, suggesting a relationship between the functions of Pik3p and Spo3p in formation of the forespore membrane in Sz. pombe.     

Influence of high molecular weight polypeptides on the mouthfeel of commercial beer

Low malt beers have high sales volumes in Japan, but improving their mouthfeel, including softness, smoothness and decreasing astringency, is challenging because the compounds responsible remain unclear. In this study, beer was fractionated by preparative size‐exclusion chromatography, with the polypeptide and maltodextrin fractions purified using solid‐phase extraction and ion‐exchange resin. Sensory data from a spike test showed that the mouthfeel (softness, smoothness, and reduced astringency) of low malt beer was improved both by the degree of polymerisation (DP) of maltodextrins (DP of 2‐10; at increased concentration of 40 to 60%; P < 0.01) and by 10 ‐ 20 kilodalton (kDa) high molecular weight (HMW) polypeptide and 2‐3 kDa low molecular weight polypeptide fractions (at a 50% increase in concentration; P < 0.01). Furthermore, highly purified 10 to 20 kDa HMW polypeptides improved the softness and smoothness and decreased the astringency (at a 25% increase in concentration). This report is the first to provide experimental sensory data indicating that HMW polypeptides improve the mouthfeel of beer. Based on these findings, a new low malt beer was developed that showed significantly higher levels of the 10‐20 kDa HMW polypeptides with an overall improved mouthfeel. Mass spectrometric analysis of the 10 to 20 kDa proteins identified several unique foam positive proteins, including barley dimeric alpha‐amylase inhibitor‐1 and non‐specific lipid‐transfer protein 1. These 10‐20 kDa HMW proteins are likely to be responsible for the improved mouthfeel of beer. © 2020 Kirin Holdings Kabushik Kaisha Co. Ltd. Journal of the Institute of Brewing published by John Wiley & Sons Ltd on behalf of The Institute of Brewing & Distilling     

Eicosapentaenoic Acid Supplementation for Chronic Hepatitis C Patients During Combination Therapy of Pegylated Interferon α-2b and Ribavirin

Eicosapentaenoic acid (EPA) (1.8 g/day) was administered to 12 chronic hepatitis C patients receiving combination therapy of pegylated interferon (PEG-IFN) α-2b and ribavirin for 48 weeks (EPA group). Twelve patients were not administered EPA (control group). All patients also received vitamin E and C (300, 600 mg/day, respectively) during the therapy. Serum alanine aminotransferase improved to a normal level in 8 of 12 patients from the EPA group and 6 of 12 patients from the control group after 12 weeks. Lymphocyte counts decreased significantly after 8 weeks in the control group, but not the EPA group. T-helper (Th) 1 decreased after 4 weeks in the control group, but not in the EPA group (two-way ANOVA; P < 0.05). Th1/Th2 ratios were elevated in 9 of 12 patients in the EPA group, and 3 out of 12 in the control group (P < 0.05) after 8 weeks. After 12 weeks, the arachidonic acid/EPA molar ratio of erythrocyte membrane phospholipid correlated negatively with the leukocyte count (n = 24, r = −0.439, P < 0.05) and the neutrophil count (n = 24, r = −0.671, P < 0.02). The hemoglobin level improved after 48 weeks compared with 24 weeks in only the EPA group. These findings suggest that EPA supplementation may be useful in therapy for chronic hepatitis C.     

Bacterial biofilm on successful and failed orthodontic mini‐implants—a scanning electron microscopy study

Mini‐implants have been extensively used in Orthodontics as temporary bone anchorage devices. However, early failure of mini‐implants due to mobility might occur and the colonization of their surfaces by pathogenic bacteria has been referred to as one of the contributing factors. In this study, scanning electron microscopy (SEM) was used to assess the presence of microorganisms adhered to the surface of mini‐implants that failed due to loss of stability. Twelve self‐drilling titanium mini‐implants (1.6 mm diameter × 9.0 mm long) were collected from 12 patients undergoing orthodontic treatment—7 successful and 5 failed mini‐implants. The mean time of permanence in the mouth was 15.8 and 2.4 months for successful and failed mini‐implants, respectively. The devices were placed in the maxilla and/or mandible and removed by the same surgeon and were processed for SEM analysis of the presence of microorganisms on their surfaces (head, transmucosal profile, and body). Extensive bacterial colonization on mini‐implant head and transmucosal profile was observed in all successful and failed mini‐implants. None of the failed mini‐implants exhibited bacteria on its body and only one mini‐implant belonging to the successful (stable) group exhibited bacteria on its body. The results did not suggest a relationship between failure and presence of bacterial colonies on mini‐implant surfaces. Microsc. Res. Tech. 78:1112–1116, 2015. © 2015 Wiley Periodicals, Inc.