ABSTRACT
Objective To detect and analyze the susceptibility genes of methyl acetate poisoning in patients by whole exome sequencing. Methods Two patients with occupational acute severe methyl acetate poisoning and their first-degree relatives who work in the same occupation and position with similar working hours were selected as the research subjects by judgment sampling method. Peripheral blood was collected for whole exome sequencing. The sequencing data was compared with the public genome database to screen the mutation sites and find out the gene sites related to methyl acetate poisoning. The suspected pathogenic mutation genes were annotated and interpreted. Results The results of whole exome sequencing showed that there were 40 differential genes between the patients with methyl acetate poisoning and their first-degree relatives, including 80 single nucleotide polymorphisms and eight Indel with specific marker sequence index. Among these, the genes with strong correlation were carboxyesterase 1 (CES1) and mucin (MUC) 5B. The CES1 gene loci c.248C>T (p.Ser83Leu) heterozygous mutations, MUC5B gene loci c.6635C>T (p.Thr2212Met) and c.7685C>T (p.Thr2562Met) heterozygous mutations in patients with methyl acetate poisoning were detected. They were missense mutations. By constructing a protein-protein interaction network, a total of 11 pairs of interactions with high levels of evidence were identified, involving genes such as lysine methyltransferase 2C, HECT and RLD domains containing E3 ubiquitin protein ligase 2, neutrophil cytoplasmic factor 1, nicotinamide adenine dinucleotide phosphate oxidase 3, C-terminal binding protein 2, zinc finger protein 717, FSHD region gene 2 family member C, FSHD region gene 1, MUC4, MUC6, MUC5B, and MUC12. Conclusion The polymorphism of CES1 and MUC5B genes may be related to the occurrence and development of methyl acetate poisoning in patients.
ABSTRACT
Objective: To investigate the specificity of endogenous metabolic profile in plasma of patients with occupational acute methyl acetate poisoning using non-targeted metabolomics. Methods: A total of six patients with occupational acute methyl acetate poisoning were selected as the poisoning group, while 10 healthy workers without occupational exposure history of chemical hazards in the same industry were selected as the control group using the judgment sampling method. Metabolites in patient plasma of the two groups were detected using ultra-high performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry, and non-targeted metabolomics analysis was performed. Principal component analysis and partial least squares discriminant analysis were used to identify differential metabolites and analyze their metabolic pathways. Results: There were significant differences in metabolite profiles in patient plasma between poisoning group and control group. A total of 195 differentially expressed metabolites were screened in plasma of patients in poisoning group, including 119 upregulated and 76 downregulated metabolites. Lipid substances (lipids and lipid-like molecules) accounted for the highest proportion (21.5%). The differential metabolites of poisoning group were related to folate biosynthesis, amino acid metabolism, pyrimidine metabolism, sphingolipid biosynthesis and other metabolic pathways in plasma compared with the control group (all P<0.05). Conclusion: Occupational acute methyl acetate poisoning affects metabolism of the body. The folic acid biosynthesis, amino acid and lipid metabolism and other pathways may be involved in the occurrence and development of poisoning.
ABSTRACT
Objective: To study the chemical constituents of Artemisia integrifolia. Methods: Solvent extraction, silica gel column chromatography, and HPLC were used for isolation and purification. The structure was identified by NMR spectrum analysis. Anti-oxidant activity tests were performed using DPPH. Results: A total of 21 monomeric compounds were isolated from A. integrifolia and identified as 2R-(2Z-pentenoic acid methyl ester)-3S-(methyl acetate) cyclopentanone (1), methyl-4S-6α-hydroxy-3- oxoeudesma-1,11 (13)-dien-12-oate (2), methyl caffeate (3), dextrin inositol (4), monobutyl fumarate (5), caffeic acid (6), monobutyl malonate (7), 6,8-dimethoxycoumarin-7-O-β-D-glucoside (8), 3,5-O-di-caffeoyl quinic acid butyl ester (9), 3,4-O-dicaffeoyl quinic acid butyl ester (10), 4,5-O-dicaffeoyl quinic acid butyl ester (11), 3,5-O-dicaffeoyl quinic acid methyl ester (12), 4,5-O- dicaffeoylquinic acid (13), 1,5-O-dicaffeoylquinic acid (14) 3,5-O-dicaffeoylquinic acid (15), o-hydroxycinnamic acid glucoside (16), 1,3-O-dicaffeoyl quinic acid (17), chlorogenic acid (18), 3,4-O-dicaffeoylquinic acid (19), methyl 3,4-O-dicaffeoylquinate (20), and o-hydroxycinnamate methyl glucoside (21). Conclusion: Compound 1 is a new natural product. Compounds 2, 5, 7-11, 14, 16, and 21 are isolated from Artemisia for the first time, and the rest are isolated from A. integrifolia for the first time. Both caffeoyl quinic acid compounds had strong anti-oxidant capacity, and the activity is basically equivalent to Vc.
ABSTRACT
PURPOSE: This study evaluated the effect of chemical surface treatment using methyl formate-methyl acetate (MF-MA) solution on the tensile bond strength between acrylic denture teeth and auto-polymerized acrylic resin. MATERIALS AND METHODS: Seventy maxillary central incisor acrylic denture teeth for each of three different brands (Yamahachi New Ace; Major Dent; Cosmo HXL) were embedded with incisal edge downwards in auto-polymerized resin in polyethylene pipes and ground with silicone carbide paper on their ridge lap surfaces. The teeth of each brand were divided into seven groups (n=10): no surface treatment (control group), MF-MA solution at a ratio of 25:75 (v/v) for 15 seconds, 30 seconds, 60 seconds, 120 seconds, 180 seconds, and MMA for 180 seconds. Auto-polymerized acrylic resin (Unifast Trad) was applied to the ground surface and polymerized in a pressure cooker. A tensile strength test was performed with a universal testing machine. Statistical analysis of the results was performed using two-way analysis of variance (ANOVA) and post-hoc Dunnett T3 test (α=.05). RESULTS: The surface treatment groups had significantly higher mean tensile bond strengths compared with the control group (P.05), except for the Yamahachi New Ace MF-MA 180-second group (P<.05). CONCLUSION: 15-second MF-MA solution can be an alternative chemical surface treatment for repairing a denture base and rebonding acrylic denture teeth with auto-polymerized acrylic resin, for both conventional and cross-linked teeth.
Subject(s)
Denture Bases , Dentures , Incisor , Polyethylene , Polymers , Silicon , Silicones , Tensile Strength , ToothABSTRACT
En este trabajo se midió experimentalmente el equilibrio líquido vapor para el sistema binario Metanol - Acetato de Metilo a 580 mmHg. Las mediciones experimentales fueron realizadas utilizando un equipo con recirculación tipo Cottrell. Los datos obtenidos fueron comparados con los resultados adquiridos de la simulación del equilibrio líquido vapor del sistema bajo estudio. En la simulación se empleó el modelo de actividad NRTL para representar la no idealidad de la fase líquida (con parámetros encontrados en la literatura), y la ecuación de estado de Hayden O´Connel para la no idealidad de la fase vapor. De igual manera, se correlacionaron los datos para encontrar nuevos parámetros del modelo de actividad en NRTL. Además, a partir de datos experimentales medidos a 760 mmHg encontrados en la literatura para el sistema estudiado, se verificó la ley de Vresky, la cual permite sin necesidad de cálculos rigurosos predecir la dirección de desplazamiento de un azeótropo binario cunado se varía la presión del sistema.
In this work the liquid - vapor binary equilibrium for the system Methanol - Methyl Acetate was measured at 580 mmHg using equipment with recirculation that also can be employed for reactive mixtures. The obtained data was compared with liquid vapor equilibrium prediction employing NRTL activity model for the liquid phase (using parameters found in the literature) and the Hayden O´Connel's equation of state for the non ideality of vapor phase. New parameters of NRTL activity model were obtained. The Vresky law that permits without rigorous calculations to predict qualitatively the displacement of binary azeotropes by pressure changes was confirmed, using various experimental data that is reported in the literature for this system at 760 mm Hg.
ABSTRACT
The transesterification reaction conditions of lard with methyl acetate with combined use of immobilized lipases as catalysts were conducted. Initially, according to single factorial experiments, the studies on Lipozyme TL IM and Novozym 435 respectively catalyzed transesterification of lard showed that the optimal parameters of transesterification reaction were: the molar ratio of methyl acetate to oil of 14∶1, 40% enzyme added based on oil weight, temperature 50℃. Combined use of Lipozyme TL IM and Novozym 435 was proposed further to improve the catalytic performance by the response surface method (RSM). Herein, a 5-level-3-factor central composite rotated design was employed to evaluate the effects of lipase loading, the proportion of the two lipases and amount of methyl acetate. The optimum conditions were as followings: 40% lipase loading based on oil weight, 50%/50% the proportion of lipases (Novozym 435/Lipozyme TL IM), and the molar ratio of methyl acetate to oil of 14∶1. And under the optimal conditions, the highest biodiesel yield of 97.6% could be attained, which was higher than the biodiesel yield with each single one of the two lipases. The results suggested that the technics of combined use of certain immobilized lipases catalyzed transesterification reaction of lard for biodiesel production with methyl acetate as the acyl acceptor could raise the FAME yield and save the production cost.