Radiation induced graft polymerization on polymeric matrix followed by functionalization is widely accepted for the preparation of metal adsorbents. In this paper, a pre-irradiation method was used for emulsion graft ...Radiation induced graft polymerization on polymeric matrix followed by functionalization is widely accepted for the preparation of metal adsorbents. In this paper, a pre-irradiation method was used for emulsion graft polymerization of 4-hydroxybutyl acrylate glycidylether (4-HB) onto polyethylene/polypropylene (PE/PP) nonwoven fabric. The degree of grafting (Dg) which can be calculated by weight increment was determined as a function of reaction time, irradiation dose, and monomer concentration. After 30 kGy irradiation, with 4-HB concentration of 5%, surfactant Span 20 of 0.5% at 40°C for 2 h, the trunk polymer was made grafted at a Dg of 135%. 4-HB-grafted PE/PP nonwoven fabric was modified by ethylenediamine (EDA) in isopropyl alcohol (IPA) as a solvent at 60°C. With a Dg of 135%, the amine group density of the adsorbent is 2.8 mmol/g. The adsorption test was carried out by batch experiment in several metal ion solutions, and the removal ratio from the EDA modified adsorbent of the metal ions is in the order of Cu2+ > Pb2+ > Zn2+ > Ni2+ > Li+. Compared with glycidyl methacrylate (GMA) which is a typical functional monomer for graft polymerization, 4-HB-grafted adsorbent exhibited not only better mechanical property but also higher adsorption capacity of Cu2+ and Pb2+.展开更多
Objective To evaluate the genotoxic and nongenotoxic effects of short-term exposure to glycidyl mathacrylate (GMA) on human lung fibroblast cells (2BS cells) in vitro. Methods DNA strand breakage was determined by sin...Objective To evaluate the genotoxic and nongenotoxic effects of short-term exposure to glycidyl mathacrylate (GMA) on human lung fibroblast cells (2BS cells) in vitro. Methods DNA strand breakage was determined by single cell gel electrophoresis, and DNA ladder formation assay and flow cytometric analysis were carried out to detect apoptic responses of cells to GMA exposure. The HPRT gene mutation assay was used to evaluate the mutagenicity, and the effect of GMA on gap junctional intercellular communication (GJIC) in the exposed cells was examined with the scrape loading/dye transfer technique. The ability of GMA to transform 2BS cells was also tested by an in vitro cell transformation assay. Results Exposure to GMA resulted in a dose-dependent increase in DNA strand breaks but not apoptic responses. GMA was also shown to significantly induce HPRT gene mutations and morphological transformation in 2BS cells in vitro. In contrast, GMA produced a concentration-dependent inhibition of GJIC. Conclusions GMA elicits both genotoxic and nongenotoxic effects on 2BS cells in vitro. The induction of DNA damage and gene mutations and inhibition of GJIC by GMA may casually contribute to GMA-induced cell transformation.展开更多
Synthesis and characterization of the copolymers (PAG) of α-methyl styrene (AMS) and glycidyl methacrylate (GMA) are presented. The copolymers of PAG were characterized by gel permeation chromatography (GPC),...Synthesis and characterization of the copolymers (PAG) of α-methyl styrene (AMS) and glycidyl methacrylate (GMA) are presented. The copolymers of PAG were characterized by gel permeation chromatography (GPC), Fourier transform infrared spectroscopy (FTIR), nuclear magnetic resonance (^1H-NMR) and thermogravimetery (TG). Based on the copolymer compositions determined by ^1H-NMR, the reactivity ratios of AMS and GMA were found to be 0.105 ± 0.012 and 0.883 ± 0.046 respectively by Kelen-Tudos method. TG revealed that thermal stability of the copolymers decreased with increasing the AMS content in the copolymers, which indicated that the degradation was mainly caused by the chain scission of AMS-containing structures. Under heating, the copolymers depolymerize at their weak bonds and form chain radicals, which could further initiate other chemical reactions.展开更多
Objective To establish the model of human bronchial epithelial cells (16HBE) malignant transformation induced by glycidyl methacrylate (GMA) and define the different methylation genes at different stages. Methods ...Objective To establish the model of human bronchial epithelial cells (16HBE) malignant transformation induced by glycidyl methacrylate (GMA) and define the different methylation genes at different stages. Methods DNA was extracted at different 16HBE malignant phases and methylation at different stages were detected using Methylation chip of Promoter Microarray Methylation'. Methylation-specific PCR (MSP) was methylation status of some genes, and then compared with the control groups. changes of genes DNA 'NimbleGen HG18 CpG used to observe the Results The result showed that GMA induced 16HBE morphorlogical transformation at the dose of 8 I^g/mL, and cell exposed to GMA had 1 374 genes in protophase, 825 genes in metaphase, 1 149 genes in anaphase, respectively; 30 genes are all methylation in the 3 stages; 318 genes in protophase but not in metaphase and anaphase; 272 genes in metaphase but not in protophase and anaphase; 683 genes in anaphase but not in metaphase and protophase; 73 genes in protophase and metaphase but not in anaphase; 67 genes in protophase and anaphase but not in metaphase; 59 genes in metaphase and anaphase but not in protophase. Conclusion The pattern of DNA methylation could change in the process of 16HBE induced by GMA.展开更多
Objective To define the differences in gene expression patterns between glycidyl methacrylate (GMA)-transformed human lung fibroblast cells (2BS cells) and controls. Methods The mRNA differential display polymerase...Objective To define the differences in gene expression patterns between glycidyl methacrylate (GMA)-transformed human lung fibroblast cells (2BS cells) and controls. Methods The mRNA differential display polymerase chain reaction (DD-PCR) technique was used. cDNAs were synthesized by reverse transcription and amplified by PCR using 30 primer combinations. After being screened by dot blot analysis, differentially expressed cDNAs were cloned, sequenced and confirmed by Northern blot analysis. Results Eighteen differentially expressed cDNAs were cloned and sequenced, of which 17 were highly homologous to known genes (homology = 89%-100%) and one was an unknown gene. Northern blot analysis confirmed that eight genes encoding human zinc finger protein 217 (ZNF217), mixed-lineage kinase 3 (MLK-3), ribosomal protein (RP) L15, RPL41, RPS16, TBX3, stanniocalcin 2 (STC2) and mouse ubiquitin conjugating enzyme (UBC), respectively, were up-regulated, and three genes including human transforming growth factor b inducible gene (Betaig-h3), a-1,2-mannosidase 1A2 (MAN 1A2) gene and an unknown gene were down-regulated in the GMA-transformed cells. Conclusion Analysis of the potential function of these genes suggest that they may be possibly linked to a variety of cellular processes such as transcription, signal transduction, protein synthesis and growth, and that their differential expression could contribute to the GMA-induced neoplastic transformation.展开更多
Glycidyl methaerylate (GMA) is a recently recognized chemical mutagen. In order to explore the mutagenicity and mutagenic process of GMA, plasmid pBR322 was used for in vitro binding, mutant screening, and restriction...Glycidyl methaerylate (GMA) is a recently recognized chemical mutagen. In order to explore the mutagenicity and mutagenic process of GMA, plasmid pBR322 was used for in vitro binding, mutant screening, and restriction enzyme mapping. The binding between GMA and DNA in vitro has been verified by means of a spectrophotometric method. When pBR322 and GMAbound pBR322 were used to transform Eschenchia coli HB101, the following results were obtained: (1) The transformation efficiency of GMA-bound pBR322 was much lower than that of pBR322 alone. (2) GMA-bound pBR322 induced phenotype changes in competent cells (i.e., tetracycline-resistance inactivation or ampicillin-resistance inactivation). There were two mutants of pBR322, Ap~RTc~S and Ap~STc~R, in the transformants and a deductive mutant Ap~STc~S in the nontranstormants. (3) All of the selected mutants were stable and heritable. (4) When restriction enzyme maps were used to analyze the mutant Ap~RTc~S, four of seven maps were changed. some sites were shifted to other resistant gene regions, for example, sites of Bgll, EcoRl, Ilindlll. Hinclll, etc., and there was a new recognition site for Hindi (252). We did not observe any DNA fragment insertion or deletion on any maps. Our results suggest that when GMA is covalently linked to the plasmid DNA, it gives rise to a premutagenic lesion of DNA that is converted in vivo into a point mutation. (C)1990 Academic Press, Inc.展开更多
A simple method for rapid estimation of the enantioselectivity of lipase in resolution of chiral esters is described. The enantioselectivity of lipase can be estimated rapidly through comparing the difference of hydro...A simple method for rapid estimation of the enantioselectivity of lipase in resolution of chiral esters is described. The enantioselectivity of lipase can be estimated rapidly through comparing the difference of hydrolysis rates for the racemic ester and its slow reacting enantiomer under the same condition because the difference mainly depends on the enantioselective ratio(E values). The higher the enantioselectivity of enzyme, the larger the difference of hydrolysis rate. The bromothymol blue(BTB) can be used as pH indicator for microplate reader to monitor the formation of acid in lipase-catalyzed hydrolysis of esters. This method has been successfully used to rapidly estimate the enantioselectivity of several lipases in the resolution of glycidyl butyrate.展开更多
Low molecular weight poly(glycidyl methacrylate)s (PGMAs) were prepared by photopolymerization in ethyl acetate, with benzophenone (BP) as photoinitiator, and triethylamine (TEA) as hydrogen donor. The existen...Low molecular weight poly(glycidyl methacrylate)s (PGMAs) were prepared by photopolymerization in ethyl acetate, with benzophenone (BP) as photoinitiator, and triethylamine (TEA) as hydrogen donor. The existence of semipinacol dormant end groups in PGMA was confirmed by FT-IR and ^1H-NMR, and the content of the semipinacol dormant groups was determined quantitatively by ^1H-NMR measurement. The effects of various thctors, such as reaction time, BP concentration and monomer concentration on the synthesis of the polymers were investigated systematically. The molecular weights of the polymers were also investigated with GPC. It is shown that increasing BP concentration and decreasing irradiation time and monomer concentration led to a significant decrease of the molecular weights.展开更多
A novel UV-curable diluent benzyl glycidyl ether acrylate(BGEA) was synthesized by utilizing benzyl glycidyl ether(BGE) and acrylic acid(AA) as starting materials,N,N-dimethylbenzylamine as catalyst and p-hydroxyaniso...A novel UV-curable diluent benzyl glycidyl ether acrylate(BGEA) was synthesized by utilizing benzyl glycidyl ether(BGE) and acrylic acid(AA) as starting materials,N,N-dimethylbenzylamine as catalyst and p-hydroxyanisole as inhibitor.The optimum synthetic conditions were that the concentration of N,N-dimethylbenzylamine was 0.90% of reactants by weight,the concentration of p-hydroxyanisole was 0.20% of reactants by weight,the reaction temperature was 90-100℃,and the molar ratio of BGE to AA was 1.00:1.10.The experiment shows that BGEA is a kind of good diluent.The mechanical properties of the UV-cured films with BGEA as diluent to prepare UV-curing coating were superior to that of the UV-cured films with butyl acrylate as diluent to prepare UV-curing coating.展开更多
Poly(glycidyl methacrylates)(PGMA) was grafted from zinc oxide(ZnO) nanowires via surface-initiated atom transfer radical polymerization(SI-ATRP) technique.Firstly,the ZnO nanowires were synthesized by the one-pot hyd...Poly(glycidyl methacrylates)(PGMA) was grafted from zinc oxide(ZnO) nanowires via surface-initiated atom transfer radical polymerization(SI-ATRP) technique.Firstly,the ZnO nanowires were synthesized by the one-pot hydrothermal technique.Subsequently,the ZnO was functionalized with 3-aminopropyl triethoxysilane,which was converted to macroinitiator by the esterification of them with 2-bromopropionyl bromide.PGMA grafted ZnO nanowires(PGMA-ZnO) were then synthesized in an ATRP of the GMA with CuCl/2,2`-bipyridine as the catalyst system.Kinetics studies revealed an approximate linear increase in weight of polymer with reaction time,indicating that the polymerization process owned some "living" character.The structure and composition of PGMA-ZnO were characterized with scanning electron microscope(SEM),energy-dispersive X-ray(EDX) spectrometer,fourier transform infrared spectroscopy(FT-IR) and thermogravimetric analysis(TGA).展开更多
Starch is easy to breed bacteria,which affects its performance and application in medical dressings.In this research,antibacterial starch was prepared by physical blending method with glycidyl trimethyl ammonium chlor...Starch is easy to breed bacteria,which affects its performance and application in medical dressings.In this research,antibacterial starch was prepared by physical blending method with glycidyl trimethyl ammonium chloride(GTA)and potassium sorbate as antibacterial agents.The antibacterial activities of GTA,potassium sorbate,GTA-starch and potassium sorbate-starch were investigated with the purpose of understanding the growth of bacteria in starch system.Results showed that GTA had good antibacterial activity,and the bacteriostasis rate of 0.05 g/mL GTA against Staphylococcus aureus(S.aureus)was 96.55%.The antibacterial properties of starch increased with an increase of mass fraction of potassium sorbate and then decreased with the continuously increasing of mass fraction of GTA.GTA-starch with30%GTA showed the best antibacterial activities,the bacteriostasis rate of Escherichia coli(E.coli)and S.aureus were 26.48%and20.26%,respectively;50%potassium sorbate in potassium sorbatestarch showed the best antibacterial activities,the bacteriostasis rate of E.coli and S.aureus were 67.68%and 74.75%,respectively.展开更多
The epoxide hydrolase gene(SpEH) from Sphingomonas sp. HXN-200 was synthesized and expressed in robust Escherichia coli cells that had a dual protection system. The enantioselectivity(E-value) of the recombinant SpEH ...The epoxide hydrolase gene(SpEH) from Sphingomonas sp. HXN-200 was synthesized and expressed in robust Escherichia coli cells that had a dual protection system. The enantioselectivity(E-value) of the recombinant SpEH was 7.7 and the yield of the remaining(R)-PGE was 24.3% for the hydrolysis of racemic phenyl glycidyl ether(rac-PGE). To improve the catalytic properties of SpEH, the site-directed mutagenesis was carried out based on homology modeling, sequence alignment and molecular docking. Six residues(V195, V196, F218,N226, Q312, and M332) near the active site were mutated to hydrophobic amino acids and the positive mutations were selected for combinatorial mutation. The optimal mutant SpEH^(V196A/N226A/M332A) had an enhanced E-value of 21.2 and a specific activity of 4.57 U·mg^-1-wet cells, which were 2.8-, and 2.3-fold higher than those of wild-type SpEH. The optimal temperature and p H for purified Sp EHV196 A/N226 A/M332 Ato catalyze the hydrolysis of rac-PGE were 25 ℃ and 7.0 with 200 U·mg^-1. The enantioselectivity and yield of the remaining(R)-PGE of E. coliSpEH^(V196A/N226A/M332A)increased from 7.7 to 21.2 and 24.3% to 40.9%, respectively. The molecular docking and kinetic parameter analyses showed that SpEH^(V196A/N226A/M332A) has a greater affinity toward(S)-PGE than(R)-PGE, and that it was more difficult for the O-atom of ASP170 to achieve the nucleophilic attack on the Cα of(R)-PGE, resulting in its improved enantioselectivity.展开更多
Theoretical analysis corresponding to the diffusion and reaction kinetics in a chemical reaction between carbon dioxide and phenyl glycidyl ether solution is presented. Analytical expressions pertaining to the concent...Theoretical analysis corresponding to the diffusion and reaction kinetics in a chemical reaction between carbon dioxide and phenyl glycidyl ether solution is presented. Analytical expressions pertaining to the concentration of carbon dioxide (CO2), phenyl glycidyl ether solution (PGE) and flux are obtained in terms of reaction rate constants. In this paper, a powerful analytical method, called the Adomian decomposition method (ADM) is used to obtain approximate analytical solutions for nonlinear differential equations. Furthermore, in this work the numerical simulation of the problem is also reported using Scilab/Matlab program. An agreement between analytical and numerical results is noted.展开更多
In order to chitracterizc the speclrum of mutallon indueed by glyeidyl methacrylule(GMA ), the plasmid pBR322 was modificed with this mutagen in vitro , transttclcd intoapproprate Escherichia colii host HB101. Th...In order to chitracterizc the speclrum of mutallon indueed by glyeidyl methacrylule(GMA ), the plasmid pBR322 was modificed with this mutagen in vitro , transttclcd intoapproprate Escherichia colii host HB101. The mutants were then sereened and defined by DNA sequencing . Sequence analysis reveals that G MA induces two classes of mulations deletion of the mono-. di' or fetra-base or the insertion of mono' or di-base. Both typesof mutations, with about 10 % frequency. occur predominantly at C-G runs and at5'-CNCCN-3' sequence ,which are hotspots for GMA damage and may cause frameshift mutation.展开更多
A novel UV-curable oligmer 1,4-cyclohexanedimethanol glycidyl ether acrylate(CHDMGEA) was synthesized by utilizing 1,4-cyclohexanedimethanol glycidyl ether(CHDMGE) and acrylic acid(AA) as starting materials, tri...A novel UV-curable oligmer 1,4-cyclohexanedimethanol glycidyl ether acrylate(CHDMGEA) was synthesized by utilizing 1,4-cyclohexanedimethanol glycidyl ether(CHDMGE) and acrylic acid(AA) as starting materials, triphenyl phosphine as catalyst and p-hydroxyanisole as inhibitor. The optimum synthetic conditions were that the concentration of triphenyl phosphine was 0.90% of reactants by weight, the concentration of p-hydroxyanisole was 0.20% of reactants by weight, the reaction temperature was 90-100 ℃, and the molar ratio of CHDMGE to AA was 0.5:1.1. The experimental results show that CHDMGEA is a kind of good UV-curable oligmer. The impact resistance of the UV-cured films with CHDMGEA as oligmer to prepare UV-curing coating was superior to that of the UV-cured films with bisphenol A diglycidyl ether diacrylate(BPGEA) as oligmer to prepare UV-curing coating.展开更多
Scavenging abilities of the ethylenediamine, diethylenetriamine and tris(2-aminoethyl)amine functionalized resins derived from the low cross-linked glycidyl methacrylate-styrene gels in relation to the selected transi...Scavenging abilities of the ethylenediamine, diethylenetriamine and tris(2-aminoethyl)amine functionalized resins derived from the low cross-linked glycidyl methacrylate-styrene gels in relation to the selected transition metal ions and organic (acid chlorides) electrophiles were explored. The synergetic effects of the solvents were found for the metal ion uptake. In this case a pair of solvents capable simultaneously to swell the hydrophobic core of the resins and interact with the polar amine groups turned out to be a more effective medium for activation of the nucleophilic functionalities of the resins. The resin with ethylenediamine moieties proved to be effective in scavenging acyl chlorides from methylene chloride as well. However, it did not provide complete removing sulphonyl chlorides from the solutions. These organic electrophiles were removed effectively by the resins bearing tris(2-aminoethyl)amine functionalities.展开更多
This paper aims to develop a modified animal glue sand binder for foundry casting with improved water resistance and bonding strength.An efficient method is reported by using sodium hydroxide as the catalyst to improv...This paper aims to develop a modified animal glue sand binder for foundry casting with improved water resistance and bonding strength.An efficient method is reported by using sodium hydroxide as the catalyst to improve the operability of animal glue binder and allyl glycidyl ether as the modifier to improve the water resistance and bonding strength.Sand specimens prepared using allyl glycidyl ether-modified animal glue binder were cured by compressed air at room temperature.The proposed method saves energy and is environmentally friendly and inexpensive.Compared with unmodified animal glue binder,standard dog bone sand specimens with allyl glycidyl ether-modified animal glue binder had higher tensile strength of 2.58 MPa,flowability of 1.95 g,better water resistance(a lower decrease in tensile strength at 25°C and relative humidity of 60%),and good collapsibility.This allyl glycidyl ether-modified animal glue binder is suitable for practical application in the foundry industry.展开更多
Poly(vinyl phosphonic acid-co-glycidyl methacrylate-co-divinyl benzene) (PVGD) and PVGD containing an iminodi-acetic acid group (IPVGD), which has indium ion selectivity, were synthesized by suspension polymerization,...Poly(vinyl phosphonic acid-co-glycidyl methacrylate-co-divinyl benzene) (PVGD) and PVGD containing an iminodi-acetic acid group (IPVGD), which has indium ion selectivity, were synthesized by suspension polymerization, and their indium adsorption properties were investigated. The synthesized PVGD and IPVGD resins were characterized using Fourier transform infrared (FT-IR) spectroscopy, scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS) and mercury porosimetry. The cation-exchange capacity, the water uptake and the indium adsorption properties were investigated. The cation-exchange capacities of PVGD and IPVGD were 1.2 - 4.5 meq/g and 2.5 - 6.4 meq/g, respectively. The water uptakes were decreased with increasing contents of divinyl benzene (DVB). The water uptake values were 25% - 40% and 20% - 35%, respectively. The optimum adsorption of indium from a pure indium solution and an artificial indium tin oxide (ITO) solution by the PVGD and IPVGD ion-exchange resins were 2.3 and 3.5 meq/g, respectively. The indium adsorption capacities of IPVGD were higher than those of PVGD. The indium ion adsorption selectivity in the artificial ITO solution by PVGD and IPVGD was excellent, and other ions were adsorbed only slightly.展开更多
Reaction products of 2,4,6-tris(4-phenyl-phenoxy)-1,3,5-triazine derived from 4-phenylphenol cyanate ester and phenyl glycidyl ether were analyzed. In addition to an isocyanurate compound and an oxazolidone compound w...Reaction products of 2,4,6-tris(4-phenyl-phenoxy)-1,3,5-triazine derived from 4-phenylphenol cyanate ester and phenyl glycidyl ether were analyzed. In addition to an isocyanurate compound and an oxazolidone compound which were well known as reaction products of cyanate esters and epoxy resins, compounds with hybrid ring structure of cyanurate/isocyanurate were determined. Gibbs free energies of the compound having hybrid ring structure of cyanurate/isocyanurate with two isocyanurate moiety were found to be lower than that of the compound with cyanurate ring structure through calculations. Calculation data supported the existence of hybrid ring structure of cy-anurate/isocyanurate. It was revealed that isomerization from cyanurate to isocyanurate occurs via hybrid ring structure of cyanurate/isocyanurate in the reaction of aryl cyanurate and epoxy.展开更多
文摘Radiation induced graft polymerization on polymeric matrix followed by functionalization is widely accepted for the preparation of metal adsorbents. In this paper, a pre-irradiation method was used for emulsion graft polymerization of 4-hydroxybutyl acrylate glycidylether (4-HB) onto polyethylene/polypropylene (PE/PP) nonwoven fabric. The degree of grafting (Dg) which can be calculated by weight increment was determined as a function of reaction time, irradiation dose, and monomer concentration. After 30 kGy irradiation, with 4-HB concentration of 5%, surfactant Span 20 of 0.5% at 40°C for 2 h, the trunk polymer was made grafted at a Dg of 135%. 4-HB-grafted PE/PP nonwoven fabric was modified by ethylenediamine (EDA) in isopropyl alcohol (IPA) as a solvent at 60°C. With a Dg of 135%, the amine group density of the adsorbent is 2.8 mmol/g. The adsorption test was carried out by batch experiment in several metal ion solutions, and the removal ratio from the EDA modified adsorbent of the metal ions is in the order of Cu2+ > Pb2+ > Zn2+ > Ni2+ > Li+. Compared with glycidyl methacrylate (GMA) which is a typical functional monomer for graft polymerization, 4-HB-grafted adsorbent exhibited not only better mechanical property but also higher adsorption capacity of Cu2+ and Pb2+.
基金This work was supported by a grant from the National Natural Science Foundation of China (grant no. 39840017).
文摘Objective To evaluate the genotoxic and nongenotoxic effects of short-term exposure to glycidyl mathacrylate (GMA) on human lung fibroblast cells (2BS cells) in vitro. Methods DNA strand breakage was determined by single cell gel electrophoresis, and DNA ladder formation assay and flow cytometric analysis were carried out to detect apoptic responses of cells to GMA exposure. The HPRT gene mutation assay was used to evaluate the mutagenicity, and the effect of GMA on gap junctional intercellular communication (GJIC) in the exposed cells was examined with the scrape loading/dye transfer technique. The ability of GMA to transform 2BS cells was also tested by an in vitro cell transformation assay. Results Exposure to GMA resulted in a dose-dependent increase in DNA strand breaks but not apoptic responses. GMA was also shown to significantly induce HPRT gene mutations and morphological transformation in 2BS cells in vitro. In contrast, GMA produced a concentration-dependent inhibition of GJIC. Conclusions GMA elicits both genotoxic and nongenotoxic effects on 2BS cells in vitro. The induction of DNA damage and gene mutations and inhibition of GJIC by GMA may casually contribute to GMA-induced cell transformation.
文摘Synthesis and characterization of the copolymers (PAG) of α-methyl styrene (AMS) and glycidyl methacrylate (GMA) are presented. The copolymers of PAG were characterized by gel permeation chromatography (GPC), Fourier transform infrared spectroscopy (FTIR), nuclear magnetic resonance (^1H-NMR) and thermogravimetery (TG). Based on the copolymer compositions determined by ^1H-NMR, the reactivity ratios of AMS and GMA were found to be 0.105 ± 0.012 and 0.883 ± 0.046 respectively by Kelen-Tudos method. TG revealed that thermal stability of the copolymers decreased with increasing the AMS content in the copolymers, which indicated that the degradation was mainly caused by the chain scission of AMS-containing structures. Under heating, the copolymers depolymerize at their weak bonds and form chain radicals, which could further initiate other chemical reactions.
基金supported by National Natural Science Foundation of China(81072318)
文摘Objective To establish the model of human bronchial epithelial cells (16HBE) malignant transformation induced by glycidyl methacrylate (GMA) and define the different methylation genes at different stages. Methods DNA was extracted at different 16HBE malignant phases and methylation at different stages were detected using Methylation chip of Promoter Microarray Methylation'. Methylation-specific PCR (MSP) was methylation status of some genes, and then compared with the control groups. changes of genes DNA 'NimbleGen HG18 CpG used to observe the Results The result showed that GMA induced 16HBE morphorlogical transformation at the dose of 8 I^g/mL, and cell exposed to GMA had 1 374 genes in protophase, 825 genes in metaphase, 1 149 genes in anaphase, respectively; 30 genes are all methylation in the 3 stages; 318 genes in protophase but not in metaphase and anaphase; 272 genes in metaphase but not in protophase and anaphase; 683 genes in anaphase but not in metaphase and protophase; 73 genes in protophase and metaphase but not in anaphase; 67 genes in protophase and anaphase but not in metaphase; 59 genes in metaphase and anaphase but not in protophase. Conclusion The pattern of DNA methylation could change in the process of 16HBE induced by GMA.
基金This work was supported by a grant from the National Natural Science Foundation of China (grant No. 39840017).
文摘Objective To define the differences in gene expression patterns between glycidyl methacrylate (GMA)-transformed human lung fibroblast cells (2BS cells) and controls. Methods The mRNA differential display polymerase chain reaction (DD-PCR) technique was used. cDNAs were synthesized by reverse transcription and amplified by PCR using 30 primer combinations. After being screened by dot blot analysis, differentially expressed cDNAs were cloned, sequenced and confirmed by Northern blot analysis. Results Eighteen differentially expressed cDNAs were cloned and sequenced, of which 17 were highly homologous to known genes (homology = 89%-100%) and one was an unknown gene. Northern blot analysis confirmed that eight genes encoding human zinc finger protein 217 (ZNF217), mixed-lineage kinase 3 (MLK-3), ribosomal protein (RP) L15, RPL41, RPS16, TBX3, stanniocalcin 2 (STC2) and mouse ubiquitin conjugating enzyme (UBC), respectively, were up-regulated, and three genes including human transforming growth factor b inducible gene (Betaig-h3), a-1,2-mannosidase 1A2 (MAN 1A2) gene and an unknown gene were down-regulated in the GMA-transformed cells. Conclusion Analysis of the potential function of these genes suggest that they may be possibly linked to a variety of cellular processes such as transcription, signal transduction, protein synthesis and growth, and that their differential expression could contribute to the GMA-induced neoplastic transformation.
文摘Glycidyl methaerylate (GMA) is a recently recognized chemical mutagen. In order to explore the mutagenicity and mutagenic process of GMA, plasmid pBR322 was used for in vitro binding, mutant screening, and restriction enzyme mapping. The binding between GMA and DNA in vitro has been verified by means of a spectrophotometric method. When pBR322 and GMAbound pBR322 were used to transform Eschenchia coli HB101, the following results were obtained: (1) The transformation efficiency of GMA-bound pBR322 was much lower than that of pBR322 alone. (2) GMA-bound pBR322 induced phenotype changes in competent cells (i.e., tetracycline-resistance inactivation or ampicillin-resistance inactivation). There were two mutants of pBR322, Ap~RTc~S and Ap~STc~R, in the transformants and a deductive mutant Ap~STc~S in the nontranstormants. (3) All of the selected mutants were stable and heritable. (4) When restriction enzyme maps were used to analyze the mutant Ap~RTc~S, four of seven maps were changed. some sites were shifted to other resistant gene regions, for example, sites of Bgll, EcoRl, Ilindlll. Hinclll, etc., and there was a new recognition site for Hindi (252). We did not observe any DNA fragment insertion or deletion on any maps. Our results suggest that when GMA is covalently linked to the plasmid DNA, it gives rise to a premutagenic lesion of DNA that is converted in vivo into a point mutation. (C)1990 Academic Press, Inc.
基金Supported by the National Natural Science Foundation of China(Nos.20072011, 20272017)the Foundation of Research Program of Jilin University, China.
文摘A simple method for rapid estimation of the enantioselectivity of lipase in resolution of chiral esters is described. The enantioselectivity of lipase can be estimated rapidly through comparing the difference of hydrolysis rates for the racemic ester and its slow reacting enantiomer under the same condition because the difference mainly depends on the enantioselective ratio(E values). The higher the enantioselectivity of enzyme, the larger the difference of hydrolysis rate. The bromothymol blue(BTB) can be used as pH indicator for microplate reader to monitor the formation of acid in lipase-catalyzed hydrolysis of esters. This method has been successfully used to rapidly estimate the enantioselectivity of several lipases in the resolution of glycidyl butyrate.
基金The authors are grateful to the National Natural Science Foundation of China (No. 50433040) for the financial support.
文摘Low molecular weight poly(glycidyl methacrylate)s (PGMAs) were prepared by photopolymerization in ethyl acetate, with benzophenone (BP) as photoinitiator, and triethylamine (TEA) as hydrogen donor. The existence of semipinacol dormant end groups in PGMA was confirmed by FT-IR and ^1H-NMR, and the content of the semipinacol dormant groups was determined quantitatively by ^1H-NMR measurement. The effects of various thctors, such as reaction time, BP concentration and monomer concentration on the synthesis of the polymers were investigated systematically. The molecular weights of the polymers were also investigated with GPC. It is shown that increasing BP concentration and decreasing irradiation time and monomer concentration led to a significant decrease of the molecular weights.
基金Natural Science Foundation of Jiangxi Province of China (No. 2008GZC0021)National High-Tech R&D Program of China(863 program) (No. 2002AA6Z3083)
文摘A novel UV-curable diluent benzyl glycidyl ether acrylate(BGEA) was synthesized by utilizing benzyl glycidyl ether(BGE) and acrylic acid(AA) as starting materials,N,N-dimethylbenzylamine as catalyst and p-hydroxyanisole as inhibitor.The optimum synthetic conditions were that the concentration of N,N-dimethylbenzylamine was 0.90% of reactants by weight,the concentration of p-hydroxyanisole was 0.20% of reactants by weight,the reaction temperature was 90-100℃,and the molar ratio of BGE to AA was 1.00:1.10.The experiment shows that BGEA is a kind of good diluent.The mechanical properties of the UV-cured films with BGEA as diluent to prepare UV-curing coating were superior to that of the UV-cured films with butyl acrylate as diluent to prepare UV-curing coating.
基金the National Natural Science Foundation of China (No.50730008 and 30772434)Shanghai Science & Technology Committee (No.09JC1407400 and 1052nm02000)
文摘Poly(glycidyl methacrylates)(PGMA) was grafted from zinc oxide(ZnO) nanowires via surface-initiated atom transfer radical polymerization(SI-ATRP) technique.Firstly,the ZnO nanowires were synthesized by the one-pot hydrothermal technique.Subsequently,the ZnO was functionalized with 3-aminopropyl triethoxysilane,which was converted to macroinitiator by the esterification of them with 2-bromopropionyl bromide.PGMA grafted ZnO nanowires(PGMA-ZnO) were then synthesized in an ATRP of the GMA with CuCl/2,2`-bipyridine as the catalyst system.Kinetics studies revealed an approximate linear increase in weight of polymer with reaction time,indicating that the polymerization process owned some "living" character.The structure and composition of PGMA-ZnO were characterized with scanning electron microscope(SEM),energy-dispersive X-ray(EDX) spectrometer,fourier transform infrared spectroscopy(FT-IR) and thermogravimetric analysis(TGA).
文摘Starch is easy to breed bacteria,which affects its performance and application in medical dressings.In this research,antibacterial starch was prepared by physical blending method with glycidyl trimethyl ammonium chloride(GTA)and potassium sorbate as antibacterial agents.The antibacterial activities of GTA,potassium sorbate,GTA-starch and potassium sorbate-starch were investigated with the purpose of understanding the growth of bacteria in starch system.Results showed that GTA had good antibacterial activity,and the bacteriostasis rate of 0.05 g/mL GTA against Staphylococcus aureus(S.aureus)was 96.55%.The antibacterial properties of starch increased with an increase of mass fraction of potassium sorbate and then decreased with the continuously increasing of mass fraction of GTA.GTA-starch with30%GTA showed the best antibacterial activities,the bacteriostasis rate of Escherichia coli(E.coli)and S.aureus were 26.48%and20.26%,respectively;50%potassium sorbate in potassium sorbatestarch showed the best antibacterial activities,the bacteriostasis rate of E.coli and S.aureus were 67.68%and 74.75%,respectively.
基金the National Natural Science Foundation of China(21676104,21878105,21908070)the National Key Research and Development Program of China(2018YFC1603400,2018YFC1602100)+3 种基金the Key Research and Development Program of Guangdong Province(2019B020213001)the Science and Technology Program of Guangzhou(201904010360)the Fundamental Research Funds for the Central Universities(2019PY15,2019MS100)the China Postdoctoral Science Foundation(BX20180102)for partially funding this work。
文摘The epoxide hydrolase gene(SpEH) from Sphingomonas sp. HXN-200 was synthesized and expressed in robust Escherichia coli cells that had a dual protection system. The enantioselectivity(E-value) of the recombinant SpEH was 7.7 and the yield of the remaining(R)-PGE was 24.3% for the hydrolysis of racemic phenyl glycidyl ether(rac-PGE). To improve the catalytic properties of SpEH, the site-directed mutagenesis was carried out based on homology modeling, sequence alignment and molecular docking. Six residues(V195, V196, F218,N226, Q312, and M332) near the active site were mutated to hydrophobic amino acids and the positive mutations were selected for combinatorial mutation. The optimal mutant SpEH^(V196A/N226A/M332A) had an enhanced E-value of 21.2 and a specific activity of 4.57 U·mg^-1-wet cells, which were 2.8-, and 2.3-fold higher than those of wild-type SpEH. The optimal temperature and p H for purified Sp EHV196 A/N226 A/M332 Ato catalyze the hydrolysis of rac-PGE were 25 ℃ and 7.0 with 200 U·mg^-1. The enantioselectivity and yield of the remaining(R)-PGE of E. coliSpEH^(V196A/N226A/M332A)increased from 7.7 to 21.2 and 24.3% to 40.9%, respectively. The molecular docking and kinetic parameter analyses showed that SpEH^(V196A/N226A/M332A) has a greater affinity toward(S)-PGE than(R)-PGE, and that it was more difficult for the O-atom of ASP170 to achieve the nucleophilic attack on the Cα of(R)-PGE, resulting in its improved enantioselectivity.
文摘Theoretical analysis corresponding to the diffusion and reaction kinetics in a chemical reaction between carbon dioxide and phenyl glycidyl ether solution is presented. Analytical expressions pertaining to the concentration of carbon dioxide (CO2), phenyl glycidyl ether solution (PGE) and flux are obtained in terms of reaction rate constants. In this paper, a powerful analytical method, called the Adomian decomposition method (ADM) is used to obtain approximate analytical solutions for nonlinear differential equations. Furthermore, in this work the numerical simulation of the problem is also reported using Scilab/Matlab program. An agreement between analytical and numerical results is noted.
文摘In order to chitracterizc the speclrum of mutallon indueed by glyeidyl methacrylule(GMA ), the plasmid pBR322 was modificed with this mutagen in vitro , transttclcd intoapproprate Escherichia colii host HB101. The mutants were then sereened and defined by DNA sequencing . Sequence analysis reveals that G MA induces two classes of mulations deletion of the mono-. di' or fetra-base or the insertion of mono' or di-base. Both typesof mutations, with about 10 % frequency. occur predominantly at C-G runs and at5'-CNCCN-3' sequence ,which are hotspots for GMA damage and may cause frameshift mutation.
基金Funded by the Natural Science Foundation of Jiangxi Province(20142BAB206029)
文摘A novel UV-curable oligmer 1,4-cyclohexanedimethanol glycidyl ether acrylate(CHDMGEA) was synthesized by utilizing 1,4-cyclohexanedimethanol glycidyl ether(CHDMGE) and acrylic acid(AA) as starting materials, triphenyl phosphine as catalyst and p-hydroxyanisole as inhibitor. The optimum synthetic conditions were that the concentration of triphenyl phosphine was 0.90% of reactants by weight, the concentration of p-hydroxyanisole was 0.20% of reactants by weight, the reaction temperature was 90-100 ℃, and the molar ratio of CHDMGE to AA was 0.5:1.1. The experimental results show that CHDMGEA is a kind of good UV-curable oligmer. The impact resistance of the UV-cured films with CHDMGEA as oligmer to prepare UV-curing coating was superior to that of the UV-cured films with bisphenol A diglycidyl ether diacrylate(BPGEA) as oligmer to prepare UV-curing coating.
文摘Scavenging abilities of the ethylenediamine, diethylenetriamine and tris(2-aminoethyl)amine functionalized resins derived from the low cross-linked glycidyl methacrylate-styrene gels in relation to the selected transition metal ions and organic (acid chlorides) electrophiles were explored. The synergetic effects of the solvents were found for the metal ion uptake. In this case a pair of solvents capable simultaneously to swell the hydrophobic core of the resins and interact with the polar amine groups turned out to be a more effective medium for activation of the nucleophilic functionalities of the resins. The resin with ethylenediamine moieties proved to be effective in scavenging acyl chlorides from methylene chloride as well. However, it did not provide complete removing sulphonyl chlorides from the solutions. These organic electrophiles were removed effectively by the resins bearing tris(2-aminoethyl)amine functionalities.
基金This work was supported by Chongqing Science and Technology Commission(cstc2017shmsA90014)Fundamental Research Funds for the Central Universities(XDJK2019AA003)We thank Kathryn Sole,PhD,from Liwen Bianji,Edanz Group China(www.liwenbianji.cn/ac),for editing the English text of a draft of this manuscript.
文摘This paper aims to develop a modified animal glue sand binder for foundry casting with improved water resistance and bonding strength.An efficient method is reported by using sodium hydroxide as the catalyst to improve the operability of animal glue binder and allyl glycidyl ether as the modifier to improve the water resistance and bonding strength.Sand specimens prepared using allyl glycidyl ether-modified animal glue binder were cured by compressed air at room temperature.The proposed method saves energy and is environmentally friendly and inexpensive.Compared with unmodified animal glue binder,standard dog bone sand specimens with allyl glycidyl ether-modified animal glue binder had higher tensile strength of 2.58 MPa,flowability of 1.95 g,better water resistance(a lower decrease in tensile strength at 25°C and relative humidity of 60%),and good collapsibility.This allyl glycidyl ether-modified animal glue binder is suitable for practical application in the foundry industry.
文摘Poly(vinyl phosphonic acid-co-glycidyl methacrylate-co-divinyl benzene) (PVGD) and PVGD containing an iminodi-acetic acid group (IPVGD), which has indium ion selectivity, were synthesized by suspension polymerization, and their indium adsorption properties were investigated. The synthesized PVGD and IPVGD resins were characterized using Fourier transform infrared (FT-IR) spectroscopy, scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS) and mercury porosimetry. The cation-exchange capacity, the water uptake and the indium adsorption properties were investigated. The cation-exchange capacities of PVGD and IPVGD were 1.2 - 4.5 meq/g and 2.5 - 6.4 meq/g, respectively. The water uptakes were decreased with increasing contents of divinyl benzene (DVB). The water uptake values were 25% - 40% and 20% - 35%, respectively. The optimum adsorption of indium from a pure indium solution and an artificial indium tin oxide (ITO) solution by the PVGD and IPVGD ion-exchange resins were 2.3 and 3.5 meq/g, respectively. The indium adsorption capacities of IPVGD were higher than those of PVGD. The indium ion adsorption selectivity in the artificial ITO solution by PVGD and IPVGD was excellent, and other ions were adsorbed only slightly.
文摘Reaction products of 2,4,6-tris(4-phenyl-phenoxy)-1,3,5-triazine derived from 4-phenylphenol cyanate ester and phenyl glycidyl ether were analyzed. In addition to an isocyanurate compound and an oxazolidone compound which were well known as reaction products of cyanate esters and epoxy resins, compounds with hybrid ring structure of cyanurate/isocyanurate were determined. Gibbs free energies of the compound having hybrid ring structure of cyanurate/isocyanurate with two isocyanurate moiety were found to be lower than that of the compound with cyanurate ring structure through calculations. Calculation data supported the existence of hybrid ring structure of cy-anurate/isocyanurate. It was revealed that isomerization from cyanurate to isocyanurate occurs via hybrid ring structure of cyanurate/isocyanurate in the reaction of aryl cyanurate and epoxy.