La revista Journal of Basic Sciences (antes Revista de Ciencias Básicas UJAT) es una revista electrónica multidisciplinaria, editada por la División Académica de Ciencias Básicas (DACB) de la Universidad Juárez Autónoma de Tabasco (UJAT) desde el 2002. Desde su nacimiento hasta 2014, se editaba semestralmente y de manera impresa, pero durante un proceso de reestructuración y relanzamiento, sufrió algunos cambios. A partir de 2015 cambió de título a su nombre actual, migró al formato electrónico y comenzó a publicarse cuatrimestralmente. La revista publica artículos con resultados de investigaciones científicas originales en los campos de la Física, Química, Matemáticas, Ciencias Computacionales y áreas afines. Sitio web: https://revistajobs.ujat.mx. Editor responsable: Carlos Ernesto Lobato García. Informes: jobs@ujat.mx. Es una revista de Revista de acceso libre.
Usted es libre de: Compartir — copiar y redistribuir el material en cualquier medio o formato La licenciante no puede revocar estas libertades en tanto usted siga los términos de la licencia Bajo los siguientes términos: Atribución — Usted debe dar crédito de manera adecuada , brindar un enlace a la licencia, e indicar si se han realizado cambios . Puede hacerlo en cualquier forma razonable, pero no de forma tal que sugiera que usted o su uso tienen el apoyo de la licenciante. NoComercial — Usted no puede hacer uso del material con propósitos comerciales . SinDerivadas — Si remezcla, transforma o crea a partir del material, no podrá distribuir el material modificado. No hay restricciones adicionales — No puede aplicar términos legales ni medidas tecnológicas que restrinjan legalmente a otras a hacer cualquier uso permitido por la licencia. Avisos: No tiene que cumplir con la licencia para elementos del material en el dominio público o cuando su uso esté permitido por una excepción o limitación aplicable. No se dan garantías. La licencia podría no darle todos los permisos que necesita para el uso que tenga previsto. Por ejemplo, otros derechos como publicidad, privacidad, o derechos morales pueden limitar la forma en que utilice el material.
Sleep Habits in Social Isolation due to the COVID-19 Pandemic
Objective: Identifying behaviors that influence sleep habits, whether negative or positive, will allow us to understand their impact on biopsychosocial performance during social isolation due to COVID-19. Material and methods: A systematic literature review of 50 scientific sources (Scielo, Elsevier, PubMed, Redalyc, and Google Scholar) was conducted, using keywords such as "mental health," "social isolation," "sleep habits," and "COVID-19." Some studies were discarded because they did not directly address the relationship between isolation and sleep. Results: The review revealed psychological responses such as anxiety, fear, anger, and confusion, as well as harmful habits such as insomnia, resulting from confinement. Conclusions: Social isolation increases the risk of sleep disturbances. Surveys are proposed to identify habits resulting from confinement and their direct relationship with the pandemic.
Copyright (c) 2026 JOURNAL OF BASIC SCIENCES https://creativecommons.org/licenses/by-nc-nd/4.0
Prevalence of anemia in university students of the Chontalpa Unit-UJAT
Anemia, a multifactorial hematological syndrome, represents a public health problem that can affect students' cognitive and intellectual development. This study aimed to determine the prevalence and morphological classification of anemia in new students at the Chontalpa UJAT Unit during the 2023-2024 period. A retrospective, observational, cross-sectional study was conducted on 1,339 students between the ages of 17 and 24. Hemoglobin and erythrocyte parameters were determined using a Mindray BC-30 hematological analyzer. The overall prevalence of anemia was 4.26%, with a higher incidence in women. The microcytic hypochromic type was the most frequent (47.36%). It is concluded that, although the prevalence does not represent a risk to public health and the hematological pattern suggests iron deficiency, the absence of biochemical markers limits definitive etiological confirmation. It is recommended that these studies be integrated into university epidemiological surveillance programs for accurate differential diagnosis.
Community perceptions of ash fall from El Chichonal Volcano in the riverine landscape of Aquiles Serdan, Tabasco
The 1982 eruption of the El Chichonal volcano produced a wide dispersion of volcanic ash that reached several areas of the state of Tabasco, Mexico. In the community of Aquiles Serdán (Paraíso, Tabasco), memories and local narratives about this event and its perceived environmental consequences still persist. This study aimed to document local perceptions and environmental memories regarding ashfall and the effects attributed to fluvial and agricultural settings through a qualitative approach based exclusively on semi-structured interviews. Three native inhabitants (49-70 years old), selected as key informants for having lived through the event, were interviewed, and data were analyzed through open and axial thematic coding. Testimonies described the ash as fine, light-gray, and easily dispersed by wind, later washed by rainfall into river channels, as well as local interpretations of temporary reductions in river depth and the formation of small deposits or islets in some areas. Participants also mentioned short-term effects on coconut crops and water visibility. Findings reflect situated memories and meanings attributed by the community; they do not constitute direct empirical evidence of geoenvironmental processes, but rather a qualitative record of how a distal volcanic event has been remembered and re-signified over time.
Sagittaria lancifolia in the removal of COD and nutrients from agricultural effluents using artificial subsurface flow wetlands
Constructed wetlands fix contaminants on the surface of the support medium by transforming elements through microorganisms, achieving satisfactory treatments with low energy consumption and little maintenance. To remove NO3-, TP and COD, an agricultural effluent in Tabasco was treated, with initial concentrations of 11.62 mg/L of NO3-, 71.40 mg/L of TP and 4402.20 mg/L of COD, using subsurface flow constructed wetlands with Sagittaria lancifolia, with 4 days of retention time and 0.5 m of depth with ¾” gravel. The subsurface flow control wetland (HAFSC) achieved removals of 35.6% of NO3-, 81% of TP and 99.78% of COD and the subsurface flow Constructed wetland with Sagittaria lancifolia (HAFSSl) removed 99.7% of NO3-, 83.1% of TP and 99.9% of COD. This species via Constructed wetlands shows a high potential in the phytoremediation of wastewater from the agricultural industry.
Sequential modification of brewers' spent grain by ultrasound and enzymatic hydrolysis
Brewer's spent grain (BSG), an abundant byproduct of the brewing industry, contains dietary fiber and phenolic compounds with functional potential. This study evaluated the sequential modification of BSG through ultrasound (US, 80% amplitude, 30 min) followed by Driselase enzymatic hydrolysis 1 and 4 h (EH, 1-4h) to improve its functional and antioxidant properties. Bulk density remained stable across treatments (0.286-0.313 g/cm³). US increased swelling capacity (15%), water holding capacity (22%), and oil holding capacity (54%) compared to native BSG. Sequential US→EH treatments partially attenuated these effects. Total phenolic content decreased in treated samples (31-45%), while DPPH antiradical capacity increased in US→EH treatments (14%) and ABTS activity appeared only in treated samples, maximizing with US→EH-4h. Treatments release more reactive phenolic compounds despite reduced total content. BSG modification provides improved functional ingredients for the development of functional foods.
Synthesis of benzimidazole derivatives (2-aryl-1H-benzo[d]imidazoles) using ultrasonic energy, in the absence of solvents and catalysts
This paper presents a new methodology for the synthesis of benzimidazole derivatives in the framework of green chemistry. The methodology is promoted by ultrasound, in the absence of solvents and catalysts and proceeds in a time of 2 hours. Under the optimized conditions, benzimidazoles were obtained with yields of 20-83%. This methodology promises to be efficient for obtaining benzimidazoles with great pharmacological potential, so the study of their possible synthetic scope is promising
Effectiveness of gamification in teaching mathematics to students with special educational needs
This study investigates the effects of gamification in mathematical education for students with special educational needs (SEN) in elementary school. The quasi-experimental method was adopted, and 48 SEN students were assigned to an experimental group (n=25) with a 12-week gamified intervention and a control group (n=23) taught conventionally. The game-based approach drew on online tools (e.g., Classcraft, Kahoot!) and game mechanics like points, levels, and co-operative challenges that were aligned to mathematics curriculum. Mathematical performance was also assessed through pre- and posttests, and teacher observations tracked levels of engagement. Results revealed significant improvement in the experimental group, with mean scores rising from 12.3 to 22.7 (out of 40), compared to a minimal rise from 12.9 to 15.2 in the control group. Statistical analysis also proved an unovercome effect size (Cohen's d = 1.87) and the superiority of gamification to improve logical thinking and problem-solving. Active engagement was highly correlated (r = 0.72) with grades, again demonstrating the motivational benefits of gamification. Qualitative feedback indicated improved class climate, reduced anxiety, and greater student autonomy. While the study is successful, it identifies limitations such as sampling and intervention time. It suggests longitudinal studies, wider demographics, and evaluation of digital and analog gamification.
Representable functors, Yoneda Lemma, and universal objects
In this work we explore the concepts of representability and universal object, as well as Yoneda’s Lemma, which belong to Category Theory. We provide several examples to illustrate the concepts. In order to do this, we consider objects coming from different mathematical fields, such as Linear Algebra, Topology, Ring Theory, among others. Besides, we provide proofs for the results.
Copyright (c) 2025 JOURNAL OF BASIC SCIENCES https://creativecommons.org/licenses/by-nc-nd/4.0
Elementary properties of the Dirichlet heat kernel for symmetric Markov processes and their applications
In this diffusion article some basic properties of the Dirichlet heat kernel are demonstrated. In probability theory this mathematical object is the transition density of a killed Markov process. In this work, symmetric strong Markov processes that could be discontinuous are considered. Among the basic properties demonstrated are: continuity, symmetry, and the Chapman-Kolmogorov equation. An important application to the theory of non-autonomous semilinear reaction-diffusion equations with Dirichlet boundary conditions is also presented. Diffusion in this case is the generator of the associated Markov process, which is known to be a non-local integro-differential operator.
Derivation of Maxwell's Equations via the Feynman–Dyson Proof and Its Relativistic Generalization
This work offers a detailed and conceptually transparent reconstruction of Feynman's derivation of Maxwell's equations, based on Newton's second law and the use of Poisson brackets between coordinates and velocities in Euclidean space. While pedagogically motivated, our approach is technically rigorous and clarifies the foundational assumptions underlying both the original and relativistic versions of the derivation. We begin by revisiting the Lorentz force law in a classical Euclidean framework and then reformulate it covariantly using Minkowskian tensor calculus, incorporating the minimal coupling prescription as formally established by Montesinos and Perez-Lorenzana. Their contribution highlights how Feynman's proof can be reconciled with a general and systematic application of the minimal coupling principle.
Photocatalytic Properties of ZnO Synthesized by Solid-State Combustion: Structural Analysis and Degradation of 4-Nitrophenol
This study presents the synthesis and characterization of zinc oxide (ZnO) through solid-state combustion and its application in the photodegradation of 4-nitrophenol (4-NP). The obtained ZnO exhibited a hexagonal wurtzite crystal structure. UV-Vis spectroscopy revealed a band gap of 3.31 eV and a specific surface area of 0.63 m²/g. This zinc oxide demonstrated photocatalytic activity in the degradation of 4-nitrophenol (4-NP). These results show that solid-state combustion is an effective method for producing ZnO with optimal properties for environmental applications, without the need for additional chemical agents.
Mineralogical and Edaphological Characterization of the Soils of Huimanguillo and Jalpa de Méndez, Tabasco
This study addresses the mineralogical and edaphological characterization of soils from the municipalities of Huimanguillo and Jalpa de Méndez, in Tabasco, Mexico. Through X-ray diffraction (XRD) analysis and soil profile descriptions, variations were identified in mineral composition and cation exchange capacity (CEC) between the two sites. The soils from Jalpa de Méndez showed greater mineral diversity, while those from Huimanguillo presented signs of alteration due to anthropogenic activity. Physical properties such as texture, color, and moisture, along with biological activity and organic matter content, also varied among the analyzed profiles. The results provide valuable information for understanding the productive potential of these soils and for developing appropriate strategies for their conservation and sustainable management.
Crystal size distribution and residence time in mafic rocks of the La Repartición Complex, San Luis Potosí, Mexico
La Repartición Volcanic Field (LRVF), located in the northeastern portion of the San Luis Potosí Volcanic Field, presents a variety of volcanic rock types, highlighting it as an exemplary natural laboratory for petrological analysis. Therefore, the present work aims to perform crystal size distribution (CSD) analyses and residence time calculations on plagioclase microcrystals from mafic rocks to understand the formation time and textural variation of these minerals in magmatic reservoirs. Petrographic analyses revealed that the analyzed samples present a mineralogical assemblage of olivine, pyroxene, and plagioclase embedded in a glassy matrix. CSD analyses exhibit steep slopes for all analyzed samples, and residence times indicate an approximate of 3 years, which suggests a rapid ascent of magmas to the surface at upper levels of the continental crust.
Evaluation of Rare Earth Elements in Lacustrine Sediments of the Northern Central Plateau between San Luis Potosí and Zacatecas, Mexico
The Rare Earth Elements consist of Lanthanum to Lutetium and are chemical elements which are less soluble and relatively immobile during geological processes such as low-grade metamorphism, erosion, and hydrothermal alteration. In the San Luis Potosí and Zacatecas states, there are continental type salars which concentrate lacustrine sediments. These sediments are classified as sandy and clay-silt. In this study, the Rare Earth Elements in these sediments were evaluated to identify provenance, depositional environment, and weathering. The lacustrine sediments contain more clay component are slightly enriched in ΣREE. The values normalized to chondrite show an enriched pattern in LREE against HREE and in sediments (NASC). The Negative Eu and Ce anomalies indicate a continental source and a non-oxidative environment, respectively. Meanwhile, the positive Y/Ho ratios indicate the weathering process also suggest a continental affinity
Condiciones metamórficas del grafito en el Complejo Metamórfico Paleozoico Esquisto Granjeno
El Complejo Metamórfico Paleozoico Esquisto Granjeno se compone por rocas con eductos sedimentarios e ígneos. El énfasis de este trabajo radica en la una unidad grafítica, de la cual no se ha entendido completamente su origen y evolución. Durante el metamorfismo las condiciones de grafitización corresponden a un proceso irreversible. Por lo cual el proceso de grafitización se considera un indicador confiable para estimar las condiciones térmicas máximas durante el metamorfismo. Se realizaron análisis geoquímicos en roca total y mineral con la finalidad de estimar las condiciones de grafitización y la mineralogía formada durante este proceso. Se estima que el proceso de grafitización ocurrió en dos rangos de temperatura de 318–339°C y 426–432°C. Por lo tanto, los sedimentos ricos en materia orgánica depositados en una cuenca oceánica localizada en la periferia del NW Gondwana fueron afectados por alto grado de metamorfismo regional durante el cierre de Pangea.
Grafito, geoquímica, metamorfismo, Complejo Metamórfico Paleozoico Esquisto Granjeno
Copyright (c) 2024 Journal of Basic Sciences
Síntesis de Ugi de tres componentes en presencia de metales de transición. Obtención de N-bencil-2-fenil-2-(fenilamino)acetamida
En este artículo se presenta la síntesis de la N-bencil-2-fenil-2-(fenilamino)acetamida (1) bajo las condiciones de la reacción de Ugi de tres componentes (U-3CR), utilizando nanopartículas metálicas como catalizadores. El producto (1) se obtuvo en rendimiento de 85% bajo las condiciones optimizadas.
-aminoamidas, reacciones multicomponente, reacción de Ugi de tres componentes, nanopartículas metálicas
Contaminación y deficiencia de la calidad por uso de suelos agrícolas: una revisión cualitativa
Tabasco es uno de los estados mayor productor de semillas de “cacao”, esto conlleva a que los suelos presenten contaminación por el desarrollo de actividades agrícolas. Los agroquímicos, contienen metales pesados y ocasionan efectos nocivos para el medio ambiente. Esta es una problemática que han impulsado la búsqueda de alternativas sobre el uso de agroquímicos. El objetivo de esta investigación fue analizar la cultura implementada por el productor, aplicación de agroquímicos, y el conocimiento de medidas de prevención para reducir la presencia de contaminantes, desde un enfoque metodológico cualitativo. Realizamos 2 entrevistas semiestructuradas, la primera dirigida a un productor que usa productos orgánicos y la segunda a uno que trabaja con agroquímicos. Como resultados: los productores usan los agroquímicos con criterios empíricos que conllevan a un inadecuado desempeño de estos productos. La experiencia se constituye en el conocimiento transmitido de generación en generación de la forma de cultivar las tierras.
Bacterias fijadoras de nitrógeno de vida libre provenientes de diferentes rizosferas de mangles
Los microorganismos desempeñan un rol importante en la degradación de petróleo en diversos ecosistemas contaminados; sin embargo, existen organismos resilientes con la capacidad de metabolizarlo. Por lo tanto, se investigan alternativas para remediar estos sitios a través de la biotecnología con el uso de microrganismos. El presente trabajo tuvo como objetivo obtener bacterias fijadoras de nitrógeno de vida libre capaces de degradar petróleo. Los microorganismos se obtuvieron a partir de las rizósferas de mangle: rojo (Rhizophora mangle), blanco (Laguncularia racemosa) y negro (Avicennia germinans), las cuales estaban libres de petróleo. De las tres rizósferas se obtuvieron 16 cepas bacterianas, las cuales se caracterizaron fenotípicamente, y posteriormente se sometieron a crecimiento en Agar Bushnell Hass y triple 17 con petróleo como única fuente de carbono, y determinar si eran petrofílicas. Los resultados demostraron tres especies de cepas bacterianas petrofílicas identificadas como: B1MR, B3MR perteneciente del mangle rojo y B2MN mangle negro.
bacteria, biorremediación, mangles, nitrógeno, petróleo, rizosfera
Regulación de la angiogénesis por antioxidantes en el cáncer de mama triple negativo
El cáncer de mama triple negativo (CMTN) está relacionado con un peor pronóstico y un comportamiento más agresivo. Este subtipo cuenta con una mayor frecuencia de metástasis, la cual se ve favorecida por el proceso vascularización relacionado a la angiogénesis tumoral. El objetivo del estudio fue realizar un análisis de expresión diferencial y ontología de genes (GO) en células MDA-MB-468 en respuesta al tratamiento con el antioxidante CAT-SKL, el análisis se realizó utilizando secuencias públicas contenidas en la base de datos Gene Expression Omnibus (GEO). La angiogénesis fue una de las ontologías que resultó subexpresada (DR) por el tratamiento con CAT-SKL. Los genes proangiogénicos KDR, EGR3, CCN2, S100A7, PDGFRA y FN1 se observaron disminuidos, mientras que el gen antiangiogénico IL18 se mantuvo incrementado. Adicionalmente encontramos que ontologías relacionadas con el transporte de aminoácidos se presentan sobreexpresadas (UR).
Cáncer de mama triple negativo, Angiogénesis, Antioxidante, Tratamiento alternativo
Problema de control para el modelo básico de la hepatitis C con tratamiento
En este trabajo planteamos y resolvemos numéricamente el problema de control óptimo para el tratamiento con interferón en un enfermo endémico de hepatitis C que responde a la terapia.
Hepatitis C, Control óptimo, Interferón.
Determinación el parámetro Vs30 en el Municipio de Teapa, Tabasco
Anteriormente, el estado de Tabasco era clasificado como una zona de bajo peligro sísmico, debido a la ausencia de registros de terremotos fuertes. Actualmente, existe la evidencia de que sismicidad en estados aledaños, ha causado daños considerables en la entidad. Uno de los parámetros que permite estimar los efectos que podrían tener los terremotos es la velocidad promedio de las ondas superficiales en los primeros 30 metros del subsuelo (Vs30). Este parámetro fue obtenido en 19 puntos distribuidos en el municipio de Teapa, resultando en velocidades que varían de los 257 a 556 m/s y clasificándose como suelos tipo C y D de acuerdo con NEHRP. Esto pone en evidencia que la región puede estar sujeta a amplificaciones del movimiento del suelo ante la ocurrencia de un terremoto.
Sismicidad de Tabasco, Vs30, efecto de sitio
Principales alimentos funcionales con efectos hipoglucemiantes en Diabetes mellitus
La diabetes es una alteración del metabolismo que afecta a millones de personas y aumenta el riesgo de muerte. Para controlar esta enfermedad, existen tratamientos farmacológicos y no farmacológicos. Dentro de estos últimos, se incluyen los alimentos funcionales, que son aquellos que tienen beneficios para la salud más allá de su valor nutricional. Estos alimentos pueden ayudar a regular los niveles de glucosa en sangre, que es el principal indicador de la diabetes. Para identificar qué alimentos funcionales son eficaces para la diabetes, se revisaron artículos científicos que evaluaron su efecto sobre la glucosa en ayunas, la glucosa postprandial y la hemoglobina glicosilada (HbA1c). Se encontró que el cacao, café, canela, ajo, guayaba, jengibre, arándanos y cúrcuma son alimentos funcionales que reducen estos parámetros, siendo la guayaba el más efectivo para bajar la glucosa postprandial.
diabetes, alimento funcional, glucosa, glucosa postprandial, HbA1c
Controlled release kinetics of acetaminophen from carboxymethylcellulose gel
The synthesis of carboxymethylcellulose (CMC) gels was carried out. The gels obtained were characterized by Fourier Transform Infrared Spectroscopy (FTIR), Scanning Electron Microscopy (SEM) and swelling tests. Once the hydrogels were characterized, the incorporation of the acetaminophen drug was carried out and the amount of active ingredient released by the hydrogel was determined as a function of time by Ultraviolet Visible Spectroscopy (UV-vis). Subsequently, the release of acetaminophen was performed at pH 7 and temperature of 37°C, the swelling tests showed a maximum swelling percentage of 1230 % in a time of 6 h. The results of the release were 0.0.5 % and 0.0.5 % for the hydrogel. The release results were 0.00362 mg/ml in a time of 4 h, reaching a release of 51 mg of acetaminophen/g of CMC hydrogel. In addition, this presented a Fickian type kinetics, since the value is close to 0.5.
Copyright (c) 2024 Journal of Basic Sciences https://creativecommons.org/licenses/by-nc-sa/4.0
Sustainable Replacement of MDF-Melamine Board in Discarded Binary Tables in Higher Education Institutions
The improper management of plastic waste is a global problem due to its slow degradation, which pollutes the ecosystem. Recycling high-density polyethylene (HDPE) is a sustainable solution that reduces carbon emissions compared to the production of new plastic, benefiting both the environment and the economy. This study focuses on the laboratory-scale production of HDPE boards to replace deteriorated MDF-Melamine boards in the División Académica de Ciencias Biológicas (DACBiol) at the Universidad Juárez Autónoma de Tabasco (UJAT). The compression molding process includes eight steps: collection, washing, grinding, melting, molding, pressing, demolding, and finishing. A total of 5.6 kg of HDPE was used to manufacture 16 boards measuring 17x17x1.2 cm, with epoxy resin optionally used for the final finish. The results demonstrate that recycled HDPE is a viable alternative for reducing plastic waste and pollution, offering a practical solution for public and private institutions.
Pectin Extracted from Orange Peel (Citrus Sinensis) to Obtain Bioplastic: Synergistic Effects with Alginate
Pectin, derived from agri-food industry waste, is an almost inexhaustible resource. This study aims to develop a bioplastic from pectin extracted from orange peel, combined with commercial alginate, and to investigate its physicochemical and thermal properties. Pectin was extracted using acid hydrolysis, and its degree of esterification and methoxyl content were determined through titration. The bioplastic film was obtained by ionic cross-linking method. Structural characterization was conducted with Fourier Transform Infrared (FTIR) spectroscopy, while the thermal properties of the pectin and the film were assessed via thermogravimetric analysis (TGA). The results indicated that pectin and alginate exhibited synergistic interactions through miscibility and ionic cross-linking. The bioplastic film demonstrated thermal stability, with a plateau in the range of 130 – 200 °C, indicating that the material possesses suitable properties for thermal processing.
Mechanochemical synthesis of Cu-modified zeolite A
Zeolites are crystalline materials with a wide range of applications, the diversity of which is possible due to the properties of these materials. Among their inherent characteristics, it is known that zeolites can be modified with nanoparticles and clusters of other chemical species, which gives them novel properties and allows them to find unusual applications. Therefore, the practical use of these materials can be improved by searching for new modification methods and studying the resulting materials. The objective of this work is to evaluate the results of the mechanochemical modification of zeolite A with copper. Zeolite A was synthesized according to standard methodology and then mixed with copper sulfate and subjected to milling. The original zeolite A and copper-modified zeolite CuA were examined by SEM, UV-Vis, and XRD. Subsequently, the characteristics of both samples were compared and the effect of the mechanochemical attack was studied.
Chemical analysis of the degradation of acid orange 52 using advanced oxidation technologies
The degradation of the acid orange 52 (AN) dye was carried out applying different Advanced Technologies, a cylindrical configuration recirculation reactor were used, the initial concentration of AN is 20 mg/L in 400 mL of solution, the treatment time consisted of 60 minutes, taking samples every 10 minutes and analyzing it by UV-vis spectrometry. The effect of the oxidizing agents used in individual and synergistic systems, the treatment time, the final pH, the generation of CO2 and the change in the coloration of the samples were determined. Efficiencies of up to 99% were obtained when using the O3/1 mL H2O2/UV method and 60 minutes, the final pH was 2.9 attributed to the generation of by-products, 35 mg/L of CO2 were obtained at the end of the process indicating that a percentage of mineralization was reached, finally a 100% decrease in color were observed.
Evaluation of the microbiological quality of aguamiel and pulque from San Agustín Tlaxiaca, Hidalgo, Mexico
Pulque and aguamiel contain many microorganisms and compounds with prebiotic and probiotic properties that can enhance intestinal microbiota diversity. Despite the potential benefits, their consumption has decreased. This study aimed to evaluate the microbiological quality of aguamiel and pulque from San Agustín Tlaxiaca, Hidalgo. The study examined the presence of aerobic mesophiles, total coliforms, molds, and yeasts. In aguamiel, 1.8x103 CFU/mL of aerobic mesophiles and 6.5 NMP/100mL of total coliforms were found. In pulque, the aerobic mesophiles increased to 1.02x105 CFU/mL, without totals coliforms and 6.43x106 CFU/mL of molds and yeasts. The presence of Gram-bacilli and coccobacilli, molds, and yeasts were observed. Microbiological quality is determined by various factors; however, establishing good practices will allow obtaining pulque with a lower load of unwanted microorganisms.
Determination of phthalates in PET-packaged beverages using an MSFIA method coupled with HPLC-DAD
In this work, an online preconcentration method was designed, optimized, and validated using a C18-type membrane with a Multisyrup Flow Injection Analysis (MSFIA) system coupled to HPLC-DAD equipment for the determination of contaminants derived from phthalic acid esters (DMP, DEP, and DBP) in juices stored in PET bottles. The physicochemical and hydrodynamic parameters of the method were optimized using a central composite experiment design. The method showed good precision (˂3%), a LOD of less than 0.5 μg kg–1, and a preconcentration factor of 33 times. After applying the method to 4 samples of juices, concentrations of 172.89 and 100.43 μg kg–1 of DMP and DBP were identified and quantified, respectively. Finally, recovery values that ranged between 44.12% and 141.07% were obtained for the three phthalates.
Implementation of a comic book for teaching molecular symmetry in chemistry
Herein we explore the use of a comic book as didactic material in the teaching of molecular symmetry for organic chemistry students at Juárez Autonomous University of Tabasco. The comic was designed with the purpose of facilitating knowledge acquisition of complicated chemical topics through play-based, simple, creative, and effective learning, to promote meaningful understanding and cognitive strategies. The research was carried out with a mixed approach, and a two-part survey technique was used to collect data. The collected data were tabulated using bar and pie charts for further analysis. In terms of proportions, a significant increase in the number of correct answers was observed after reading the comic book. Specifically, the correct rate increased from 30.6% initially to 55.6% after the intervention with the comic.