•Superior E. coli disinfection efficacy occurred by unactivated PMS vs. PDS/H2O2.•Kinetic, biochemical, and genetic analyses defined the inactivation path.•SO4•− was the pivotal ROS, generated by the ...reaction between PMS & biomolecules.•External oxidation leads to cell envelope disruption and intracellular attacks.•Mutants’ tests uncovered gene responses induced by intracellular radical pathways.
This study examined the antimicrobial efficacy of peroxymonosulfate (PMS) against bacteria, using Escherichia coli (E. coli) as a model organism. Our investigation delineates the complex mechanisms exerted by unactivated PMS. Thus, an initial redox reaction between PMS and the target biomolecules of bacteria generates SO4•− as the pivotal reactive species for bacterial inactivation; to a lesser extent, •OH, 1O2, or O2•− may also participate. Damage generated during oxidation was identified using an array of biochemical techniques. Specifically, redox processes are promoted by PMS and SO4•− targets and disrupt various components of bacterial cells, predominantly causing extracellular damage as well as intracellular lesions. Among these, external events are the key to cell death. Finally, by employing gene knockout mutants, we uncovered the role of specific gene responses in the intracellular damage induced by radical pathways. The findings of this study not only expand the understanding of PMS-mediated bacterial inactivation but also explain the ten-fold higher effectiveness of PMS than that reported for H2O2. Hence, we provide clear evidence that unactivated PMS solutions generate SO4•− in the presence of bacteria, and consequently, should be considered an effective disinfection method.
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An improved method based on the p-nitrophenyl long chain esters method is proposed for measuring lipase hydrolytic activity in aqueous media. Using ethylene glycol as co-solvent for hydrophobic ...p-nitrophenyl substrates in aqueous buffer, lipase activity is measured by following the release of p-nitrophenol.
This fast and easy to handle method improves the solubility of both substrate and product, and also the stability of the substrate. It avoids the use of solvents such as ethanol or propanol, permits the comparison of all the p-nitrophenol acyl ester substrates and allows the influence of ions like Ca+2 to be studied, while avoiding turbidity in the reaction medium.
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For Protected Geographical Indication (PGI)-labeled products, such as the dry-cured beef meat "cecina de León", a sensory analysis is compulsory. However, this is a complex and time-consuming ...process. This study explores the viability of using near infrared spectroscopy (NIRS) together with artificial neural networks (ANN) for predicting sensory attributes. Spectra of 50 samples of cecina were recorded and 451 reflectance data were obtained. A feedforward multilayer perceptron ANN with 451 neurons in the input layer, a number of neurons varying between 1 and 30 in the hidden layer, and a single neuron in the output layer were optimized for each sensory parameter. The regression coefficient R squared (RSQ > 0.8 except for odor intensity) and mean squared error of prediction (MSEP) values obtained when comparing predicted and reference values showed that it is possible to predict accurately 23 out of 24 sensory parameters. Although only 3 sensory parameters showed significant differences between PGI and non-PGI samples, the optimized ANN architecture applied to NIR spectra achieved the correct classification of the 100% of the samples while the residual mean squares method (RMS-X) allowed 100% of non-PGI samples to be distinguished.
•Life time prediction is based on accumulated damage & consumed time for every damage.•Fatigue has the most important contribution for the total damage of the pavement.•Higher rutting in modified ...bitumen (sasobit, cecabase, foam, RAP) compared to reference.•Bad rutting results concluded that WMA for hot climate needs further investigation.
Road surfaces with low temperature bitumen are usually used due to the lower energy consumption and environmental considerations.
This paper presents a study of the performance of low temperature bitumen, in particular, the long-term behavior and life-time prediction of some low-temperature bitumen. Six bitumen mixture samples were tested with different modifiers such as synthetic Cecabase (C), Sasobit (S), Greenseal (G) and Advera (A) wax. Pavement performance prediction in terms of fatigue cracking and surface rutting is essential for any mechanistically-based pavement design method. In this study full-scale Accelerated Pavement Testing (APT) has been used to simulate field conditions and Equivalent Standard Axles (ESAs). Fatigue response was also analyzed in the laboratory. This paper focus on developing a life time prediction model based on rutting and fatigue to describe the stable and unstable performance of six tested low energy bitumen mixtures.
HLA-DRB1 alleles has been found implicated in susceptibility to autoimmune hepatitis (AIH) in populations from different genetic backgrounds. In Mexicans, HLA-DRB1*04:04 is recognized as a risk ...allele for AIH but, to date, there is no high-resolution data supporting this association. Also, the association of other nonclassical HLA genes, such as TNF-LTA locus, have not, to our knowledge, been evaluated in this population. The association of HLA-DRB1 alleles determined by sequence-based typing and two polymorphisms in the TNF locus with AIH in a sample of Mexican patients was evaluated. Fifty-six patients from Guadalajara, Mexico, diagnosed with AIH and 115 age-gender matched healthy volunteer blood donors, were genotyped for HLA-DRB1 by the sequencing exon 2 and for TNFA-308G>A and LTA + 252A>G polymorphisms. Increased frequencies of both HLA-DRB1*04:04:01 and *16:02:01:01 alleles (OR = 2.91; 95% CI = 1.08-7.84) and the haplotype (DRB1-TNFA-LTA) *04:04:01-G-A (OR = 5.33; 95% CI = 1.32-21.49) were observed in AIH patients. However, after corrections for multiple comparisons, associations were not significant. In conclusion, our study does not support the association of HLA-DRB1*04:04:01 with the susceptibility to AIH in Mexican population. More studies including patients from other Mexican regions and considering other genetic, immunological, and environmental factors should be performed.
This study explores the viability of the application of Near Infrared Spectrometry (NIR) for the rapid prediction of the ratio of 13C/12C stable isotopes and fatty acid composition in Iberian pigs. ...The potential use of this technique for distinguishing samples according to the duration of the montanera period was also studied. Subcutaneous fat samples from 50% and 100% Iberian pigs allowed to feed freely during different montanera periods were analyzed: 24 biopsies were taken prior to the montanera and 106 samples were taken after this feeding period. The results show significant correlations between δ13C (‰) and several fatty acids. Furthermore, it is possible to differentiate samples taken from pigs reared using different feeding regimes by analyzing the data obtained from the NIR spectra or by applying an Orthogonal Partial Least Squares Discriminant Analysis (OPLS-DA) on data on δ13C (‰) and fatty acids in subcutaneous fat.
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•The δ13C (‰) and 14 fatty acids were quantified in Iberian pig fat using NIR.•The more days of montanera the greater the variation of δ13C (‰) in pig fat.•There was a correlation between δ13C and fatty acids related to the quality of Iberian products.•The production system and feeding regime were distinguished by NIRS and RMS-X residuals.•The OPLS-DA Discriminant Analysis can differentiate feeding regimes.
Red Globe grape polyphenol oxidase, partially purified using phase partitioning with Triton-X114, was used to study the oxidation of hydroxytytosol (HT) and its related compounds tyrosol (TS), ...tyrosol acetate (TSA), and hydroxytyrosol acetate (HTA). The enzyme showed activity toward both monophenols (monophenolase activity) and o-diphenols (diphenolase activity) with a pH optimum (pH 6.5) that was independent of the phenol used. However, the optimal temperature for diphenolase activity was substrate-dependent, with a broad optimum of 25–65 °C for HT, compared with the maximum obtained for HTA (40 °C). Monophenolase activity showed the typical lag period, which was modulated by pH, substrate and enzyme concentrations, and the presence of catalytic amounts of o-diphenols. When the catalytic power (V max/K M) was determined for both activities, higher values were observed for o-diphenols than for monophenols: 9-fold higher for the HT/TS pair and 4-fold higher for HTA/TSA pair. Surprisingly, this ratio was equally higher for TSA (2.2-fold) compared with that of TS, whereas no such effect was observed for o-diphenols. This higher efficiency of TSA could be related to its greater hydrophobicity. Acetyl modification of these phenols not only changes the kinetic parameters of the enzyme but also affects their antioxidant activity (ORAC-FL assays), which is lower in HTA than in HT.
La presente investigación tiene como propósito implementar huertos escolares como recurso didáctico para el desarrollo sustentable hacia una cultura ambientalista, en la Escuela Técnica Agropecuaria ...Nacional “Francisco Tamayo” de la parroquia Barinitas Municipio Bolívar estado Barinas. Tiene como objetivo fundamental dar una alternativa viable y sustentable desde la escuela hacia la comunidad. La misma se encuentra bajo el enfoque cualitativo, a través del método investigación-acción participante. El diseño metodológico está estructurado en cinco etapas: (1) Diagnóstico; (2) planificación; (3) Ejecución; (4) evaluación; (5) Sistematización. Los informantes claves estarán representados por tres docentes relacionados a la parte agrícola, tres estudiantes de tercer año sección A, y un Directivo quien dará la información pertinente que servirá de base para la planificación y ejecución de las estrategias. Las técnicas de recolección de información serán la entrevista a profundidad y la observación de documentos. Las técnicas de análisis de la información fueron la categorización, triangulación e interpretación.
The aging effect of ultraviolet (UV) radiation on bitumen has gained increasing attention from researchers, resulting in the emergence of a new method to simulate the UV aging that occurs during the ...service life of bitumen. However, the UV aging degree is closely related to bitumen thickness and the effect of UV radiation on aging depth is not clear. The relationship between ultraviolet (UV) radiation and bitumen UV aging depth was investigated in this paper. Three groups of samples were UV aged using different aging procedures to investigate the bitumen aging mechanism of UV radiation. The results from the first group showed that UV aging depth increased along with aging time. After aging for five hours, the complex modulus of the second and third layers increased. The second group's results indicated that the aging effect of ozone was small and that the increase in aging depth was uncorrelated with ozone. The results from the third group showed that the transmittance of bitumen increased after UV aging and that the real reason why aging depth increased was permeation.
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