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[en] Benzo(α)pyrene and other polycyclic aromatic hydrocarbons(PAHs) are ubiquitous environmental chemicals which are mutagenic and carcinogenic. Various PAH compounds interfere with soluble antibody formation, allograft rejection, the generation of cytotoxic T lymphocytes and natural killer cell activity. These environmental agents which alter T-lymphocyte function or natural resistance mechanisms may facilitate tumor development. In the present study, we tried to develop immunoprophylactic methods for chemical carcinogen-induced tumors by enhancing cell-mediated immunity. We assayed immunoprophylactic activities of PSK in benzo(α)pyrene-injected A/J inbred mice, and NIH (GP) noninbred mice. We are also going to measure natural killer cell activity and cytotoxic T cell activity in splenic lymphocytes and non-adherent peritoneal exudate cells of mice in which PSK showed immunoprophylactic activities for benzo(α)pyrene induced sarcoma. PSK showed immunoprophylactic activity in benzo(α)pyrene-injected A/J mice. Natural killer cell activities of splenic lymphocytes and non-adherent peritoneal exudate cells were enhanced by PSK in A/J mice injected with benzo(α)pyrene. Cytotoxic T cell activities of non-adherent peritoneal exudate cells were not enhanced by PSK in A/J mice injected with benzo(α)pyrene. These results will be used in the development of immunoprophylactic methods for chemical carcinogen induced tumors. (Author)
[en] Highlights: → The R-curve behavior of a unidirectional laminate as a material property is investigated. → Effect of initial crack length and thickness on R-curve is experimentally shown. → A mathematical relation is proposed to model the R-curve behavior of any unidirectional laminated composite. -- Abstract: It is still questionable to think of delamination resistance of a double cantilever beam (DCB) as a material property independent of the specimen size and geometry. In this research, the effects of initial crack length and DCB specimen thickness on the mode I delamination resistance curve (R-curve) behavior of different unidirectional glass/epoxy DCB specimens are experimentally investigated. It is observed that the magnitudes of initiation and propagation delamination toughness (GIc-init and GIc-prop) as well as the fiber bridging length are constant in a specific range of the initial crack length to the DCB specimen thickness ratios of 8.5 < a0/h < 19. Finally, a mathematical relationship is proposed for prediction of mode I delamination behavior (from the initiation to propagation) of E-glass/epoxy DCB specimens.
[en] Highlights: • First report of very fast synthesis of epoxy functionalized silica nanoparticles in a scalable single pot approach. • Epoxy functionalized silica nanoparticles can be used for single step immobilization of variety of dyes like fuchsin and biomolecules. • Fuchsin conjugated nanoparticles can be employed as enzyme/chemical reaction-free colorimetric probe for faster assay to result turnaround time. - Abstract: We have developed a novel method to develop epoxy silica nanoparticles (EfSiNP) in a single pot. High surface coverage of epoxy functional groups between 150 and 57000 molecules per particles (~1013–1016 molecules/mL of 200 nm EfSiNPs) was achieved for different preparation conditions. We then created a red colored probe by conjugating Fuchsin dye to the epoxy functionalities of EfSINPs. Anti-mouse IgG was co-immobilized with Fuchsin and their ratios were optimized for achieving optimum ratios by testing those in functional assays. Dye to antibody ratios were in good negative correlation with a coefficient of -1.00 measured at a confidence level of over 99%. We employed the developed non-enzymatic colorimetric immunonanoprobe for detecting mouse IgG in a direct immunoassay format. We achieved a sensitivity of 427 pg/mL with the assay.
[en] An epoxy acrylate was synthesized from Asahi's epoxy resin AER 331 which is an epoxidised soya bean oil (ESBO). Triethylamine (TEA) and Hydroquinone (HQ) were used as catalyst and inhibitor respectively. Observations of the experiment are described. (author)
[en] In the paper refraction parameter and optical spectra of epoxy-polymers polymerization initial products are measures in a wide temperature range. The recommendations for initial products use for reception of synthetic transparent polymerization of epoxy-polymers are given. (author)
[en] In this paper, a new and innovative process for assembling chains of carbon nanofibers (CNFs) in epoxy, uniquely different from those generally used for chaining particles in a liquid medium, is presented. Chains of aligned CNFs are assembled in a region rich in CNFs and extended into regions where there are no CNFs. A physical explanation of the process is provided based on the conductive nature of the CNFs. By contacting the chains with the electrodes, the process of chain growth is expedited and well-ordered parallel chains with equal spacing are grown over distances of 2 cm
[en] Tetrahydroquinolines bearing substituents are frequently found as a substructure in a number of alkaloids and natural products. Since their individual stereoisomers displays different biological activities, it is desirable to develop a highly stereoselective synthetic method for tetrahydroquinolines. While some progress has recently been made toward the development of asymmetric synthetic methods for tetrahydroquinolines, it is still a challenging topic in organic synthesis. In order to investigate the source of diastereoselection attained in the substitution reaction with a racemic epoxide, we examined the substitution of 2 with an excess amount of racemic p-chlorophenyl-substituted oxirane. We have developed a novel method for the asymmetric synthesis of trans-3,4-diaryl-substituted tetrahy- droquinolines from ortho-substituted N-pivaloyl anilines. The enantioselective process includes (+)-sparteine-mediated stereoselective lithiati on, kinetic resolution of epoxides in substitution, and stereospecific Mitsu nobu cyclization as the key reactions. The simple protocol can provide highly functionalized tetrahydroqu inoline rings and would allow their further functionalization to access more complex target molecules
[en] A new hybrid thermosetting maleimido epoxy compound 4-(N-maleimidophenyl) glycidylether (N-MPGE) is prepared by reacting N-(4-hydroxyphenyl) maleimide (HPM) with Epichlorohydrin by using benzyltrimethylammonium chloride as a catalyst. The resulting compound possesses both the oxirane ring and maleimide group. The curing reaction of these maleimidophenyl glycidylether epoxy compound (N-MPGE) with amines as curing agents such as ethylendiamine (EDA), diethylentriamine (DETA) and triethylenetetramine (TETA), aminoethylpiperazine (AEP) and isophoronediamine, IPDA), are studied. Incorporation of maleimide groups in the epichlorohydrin provides cyclic imide structure and high cross-linking density to the cured resins. The cured samples exhibited good thermal stability, excellent chemical (acid/alkali/solvent) and water absorption resistance. Morphological studies by the SEM technique further confirmed the phase homogeneity net work of the cured systems
[en] As a promising substitute for periodical metamaterials, random composites with tunable negative electromagnetic parameters, which are termed as metacomposites, have drawn extensive attention owing to their unique properties and great potential applications. It is significant to decrease the values of negative permittivity and attain weakly negative permittivity with low frequency dispersive behavior, when searching for substitutable metacomposites. In this paper, the absolute value of negative permittivity in graphene/epoxy resin composites was dramatically decreased to approximately 6 by controlling the content of graphene and the microstructure of the resultant composites. Meanwhile, the permittivity spectrum showed low frequency dispersive behavior, which kept steady in a wide scope of frequency. It is indicated that the independence of negative permittivity on frequency results from the outstanding electron mobility of graphene. Moreover, it is demonstrated that the positive permittivity is ascribed to capacitive character, and the inductive character results in negative permittivity.