Isogo Technical High School

Epoxy adhesives form strong and durable bonds to a wide range of materials such as metals, glass, concrete, ceramics, wood, and many plastics. Curing shrinkage is low. Cured epoxy resin possesses strong and rigid cross-linked chemical structure well-suited for various bonding applications. Epoxy adhesives have been widely used as typical reactive adhesives for various applications ranging from general industry, construction, electronics assembly, automobile production to aerospace and defense market. Typical conventional room temperature and thermal cure epoxy adhesives need long cure time. High performance epoxy adhesives usually require curing at high temperature conditions. Most cured epoxy adhesives are rigid and are not suitable for bonding flexible substrates. Considerable research and development efforts have been devoted to overcome these limitations and significant progress has been achieved in thermal low temperature cure epoxy adhesive development, thermal snap cure epoxy bonding technology development, UV cationic cure epoxy adhesive development, UV and thermal dual cure hybrid epoxy adhesive development, and high-performance toughened epoxy adhesive development. In the meantime, sustainable epoxy adhesive development has become increasingly important to meet the expectations from global environmental protection, government regulation restriction, and customer requirements. Latest developments and new trends in various epoxy adhesive technologies are described.

The discharge of environmental estrogenic substances into the environment has an adverse effect on human and wildlife, especially aquatic organisms. Therefore, a simple, practical and sensitive method of detecting environmental estrogenicity is required. Previously, we established a transgenic medaka (Oryzias latipes) strain harboring choriogenin L (ChgL) tagged with green fluorescence protein (GFP), which is expressed in the liver in response to estrogen (E2). This strain of medaka could be a very useful tool in detecting aquatic estrogenicity. The appropriate conditions for analysis of estrogenicity were determined at various E2 concentrations, exposure periods and the developmental stages of medaka hatchlings. Furthermore, the relationship between E2 concentrations and GFP fluorescence intensity was investigated. It was found that fluorescence intensity of GFP depends largely on E2 concentration, exposure time and developmental stage. Hatchling at 4-day post-hatch (DPH) showed optimum conditions for exposure to E2 with optimum GFP intensity at 9 DPH. Additionally, the exposure period was optimized so that exposure from 4 DPH for 5 days showed a significant change in GFP intensity. E2 concentrations of 0, 12.5, 25, 50 and 100 ng/L were used, with 25 ng/L showing a clear increase in GFP intensity at day 6 of exposure. The sensitivity of vitellogenin (Vtg) induction was also examined by Western blot and enzyme-linked immunosorbent assay (ELISA) using whole-body homogenates of E2-exposed (0, 12.5, 25, 50 and 100 ng/L) juvenile medaka. Vitellogenin induction, as determined by Western blot, was found in those juveniles exposed to E2 at a concentration of 100 ng/L. Whereas, Vtg induction was detected by ELISA from juveniles exposed to 12.5 ng/L of E2. The results suggest that ChgL-GFP transgenic medaka could be a simple and practical tool in detecting environmental estrogenicity considering the actual concentrations of estrogenic activity in contaminated and/or wastewater.

1993～2006年に横浜市内の小売店より収去された鶏肉から分離されたSalmonella Enteritidis 82株(国産鶏肉由来30株，輸入鶏肉由来52株)について薬剤感受性試験，ファージ型別，PFGE法による疫学的解析を行った．その結果，国産鶏肉由来株ではSM耐性が80%，輸入鶏肉由来株ではNA耐性が56%と薬剤感受性の傾向が異なっていた．なお，NA耐性は2003年以降増加していた．ファージ型別では1型が27%，4型が32%で全体の2/3を占めた．中国産鶏肉由来株は1型が，ブラジルおよびタイ産鶏肉由来株は4型が多く原産国別の違いが認められた．制限酵素Bln IおよびXba IによるPFGEの解析結果では，国産と輸入鶏肉由来株の泳動パターンは大きく異なり，Bln Iでは類似度46%でクラスター分類が可能であった．PFGEの結果と，薬剤感受性，PTには特に関連性は認められず，年別，国別による違いも認められなかった．