Unveiling the mechanisms of carboxylic acid esterification on acid zeolites for biomass-to-energy: A review of the catalytic process through experimental and computational studies.

In recent years, there has been significant interest from industrial and academic areas in the esterification of carboxylic acids catalyzed by acidic zeolites, as it represents a sustainable and economically viable approach to producing a wide range of high-value-added products. However, there is a lack of comprehensive reviews that address the intricate reaction mechanisms occurring at the catalyst interface at both the experimental and atomistic levels. Therefore, in this review, we provide an overview of the esterification reaction on acidic zeolites based on experimental and theoretical studies. The combination of infrared spectroscopy with atomistic calculations and experimental strategies using modulation excitation spectroscopy techniques combined with phase-sensitive detection is presented as an approach to detecting short-lived intermediates at the interface of zeolitic frameworks under realistic reaction conditions. To achieve this goal, this review has been divided into four sections: The first is a brief introduction highlighting the distinctive features of this review. The second addresses questions about the topology and activity of different zeolitic systems, since these properties are closely correlated in the esterification process. The third section deals with the mechanisms proposed in the literature. The fourth section presents advances in IR techniques and theoretical calculations that can be applied to gain new insights into reaction mechanisms. Finally, this review concludes with a subtle approach, highlighting the main aspects and perspectives of combining experimental and theoretical techniques to elucidate different reaction mechanisms in zeolitic systems.

Estudiar salud pública en la Escuela de Salud Pública de México en 1966: testimonio.

En sus 100 años de existencia, la Escuela de Salud Pública de México (ESPM) ha experimentado cambios curriculares en función del desarrollo científico y tecnológico, de las prioridades en salud y del desarrollo de las instituciones en el país. En 1966, la ESPM era un centro latinoamericano de formación de especialistas y recibía estudiantes de países latinoamericanos. El objetivo de la Maestría en Salud Pública (MSP) era formar directivos con competencia para planear y administrar programas preventivos que, en México, respondían a una organización institucional centralizada. Al igual que en otros países latinoamericanos, las prioridades en salud en México se dirigían a la prevención y control de problemas de salud maternoinfantil, a enfermedades trasmisibles prevenibles por vacunación y a las deficiencias de la nutrición. Adaptado a este contexto, el programa de estudios incorporaba materias de administración, epidemiología, estadística y ciencias sociales, vinculadas estas últimas al binomio salud-enfermedad. Después de una especialización en medicina interna, cursar la MSP y tener contacto directo con la realidad social significó, para el autor, un cambio profundo de perspectiva. En esta comunicación se relatan algunas de las experiencias más significativas vividas a lo largo del curso.

Transoperative intravitreal dexamethasone implantation in patients with proliferative vitreoretinopathy.

OBJECTIVE: To compare the anatomical results in patients with rhegmatogenous retinal detachment, at least grade B of proliferative vitreoretinopathy, and with a trans-surgical dexamethasone implant vs the control group. We also assessed the diminution of proliferative vitreoretinopathy and the final visual acuity (VA). METHOD: The patients were evaluated clinically and with optical coherence tomography for 10 months. Logistic regression analyses were performed to evaluate the effect of the dexamethasone implant on retinal detachment. Correlational analyses were explored depending on the variables' distribution, and an independent samples t-test was used to compare the VA in both groups. RESULTS: The study included 38 eyes of patients with proliferative vitreoretinopathy: 18 with the implant and 20 for the control group. The evaluation of the main objective showed significant differences (p < 0.05) in the anatomical success between the two groups (61.1% vs. 20%, treatment vs. control); odds ratio of 6.29; 95% confidence interval: 1.5- 26.8; p = 0.013; Nagelkerke's R2 = 0.225. The t-test showed a significant difference in the final VA of the patients (t = 2.047; df = 36; p = 0.048; Cohen's d = 0.66). CONCLUSIONS: Retinal redetachment was less frequent, and better VA was observed, in patients with the dexamethasone implant in comparison with the control group.

OBJETIVO: Comparar los resultados anatómicos en pacientes con desprendimiento de retina regmatógeno, vitreorretinopatía proliferativa a partir de grado B y aplicación de implante de dexametasona transquirúrgico frente a un grupo control. También se valoraron la disminución de la vitreorretinopatía proliferativa y la agudeza visual (AV) final. MÉTODO: Los pacientes se evaluaron clínicamente y con tomografía de coherencia óptica por 10 meses. Se realizaron análisis de regresión logística para evaluar el efecto del implante en el redesprendimiento de retina. Se exploraron análisis correlacionales dependiendo de la distribución de variables y se aplicó la prueba t de muestras independientes para comparar la AV en ambos grupos. RESULTADOS: Se incluyeron 38 ojos de pacientes con vitreorretinopatía proliferativa: 18 con el implante y 20 del grupo control. La evaluación del objetivo principal mostró diferencias significativas (p < 0.05) en el éxito anatómico entre ambos grupos (61.1% en los ojos con tratamiento frente a 20% en el grupo control); razón de momios de 6.29; intervalo de confianza del 95%: 1.5- 26.8; p = 0.013; R2 de Nagelkerke = 0.225. La prueba t mostró una diferencia significativa entre la AV final de los pacientes (t = 2.047; gl = 36; p = 0.048; d de Cohen = 0.66). CONCLUSIONES: Se observó menor redesprendimiento, así como mejor AV, en los pacientes con el implante de dexametasona en comparación con el grupo control.

Physical capability in a rural birth cohort at the age of 52: association with early environmental, nutritional, and developmental factors.

INTRODUCTION: Midlife physical capability (PC) is associated with developmental factors in the populations of economically developed countries. As far as we know, there is no information for rural populations of low- and middle-income countries. The aim of the study was to investigate the influence of pre- and postnatal factors on midlife objective measures of PC in a 1966-67 birth cohort from a Mexican rural community. The hypothesis was that adverse developmental conditions are associated with low midlife PC. METHODS: In 1966-67, a birth cohort of all children from a poor Mexican rural community was assembled. Data on family socioeconomic status (SES), parental health and nutritional status, birth weight, postnatal growth and feeding patterns were registered. In 2018, out of the 336 cohort members, 118 were living in the community, and eighty-two of them underwent a comprehensive clinical evaluation. The evaluation included grip strength, gait velocity and chair-stand PC tests. In multivariable linear models, PC tests were the dependent variables, and prenatal, birth and postnatal factors were the independent variables. Adjustment for confounding was made with adult anthropometric, body composition, clinical and ageing status variables. RESULTS: Independent of adult health status and other ageing indicators, lower PC was associated with family organization and SES, parental nutritional status, birth weight, infant postnatal growth velocity, and weaning time. These results indicate that adverse family and environmental conditions that are prevalent in poor rural communities are associated with low midlife PC.

Years of Schooling Could Reduce Epigenetic Aging: A Study of a Mexican Cohort.

Adverse conditions in early life, including environmental, biological and social influences, are risk factors for ill-health during aging and the onset of age-related disorders. In this context, the recent field of social epigenetics offers a valuable method for establishing the relationships among them However, current clinical studies on environmental changes and lifespan disorders are limited. In this sense, the Tlaltizapan (Mexico) cohort, who 52 years ago was exposed to infant malnutrition, low income and poor hygiene conditions, represents a vital source for exploring such factors. Therefore, in the present study, 52 years later, we aimed to explore differences in clinical/biochemical/anthropometric and epigenetic (DNA methylation) variables between individuals from such a cohort, in comparison with an urban-raised sample. Interestingly, only cholesterol levels showed significant differences between the cohorts. On the other hand, individuals from the Tlaltizapan cohort with more years of schooling had a lower epigenetic age in the Horvath (p-value = 0.0225) and PhenoAge (p-value = 0.0353) clocks, compared to those with lower-level schooling. Our analysis indicates 12 differentially methylated sites associated with the PI3-Akt signaling pathway and galactose metabolism in individuals with different durations of schooling. In conclusion, our results suggest that longer durations of schooling could promote DNA methylation changes that may reduce epigenetic age; nevertheless, further studies are needed.

Enhanced removal of bisphenol A using pine-fruit shell-derived hydrochars: Adsorption mechanisms and reusability.

We synthesized NaOH-activated hydrochars via hydrothermal carbonization (HTC) of Brazilian pine fruit shells at HTC residence times of 24, 48, and 72 h. The hydrochars were used as adsorbents to remove bisphenol A (BPA) from aqueous solutions. The surface area of the samples can reach up to 2220 m2 g-1, and the maximum adsorption of BPA onto the surfaces was achieved at a pH of 7.0 (708 mg g-1). Adsorption occurred mainly via monolayer formation with a low retention time of the adsorbate (τ) on the surfaces, indicating that the BPA molecules reached the already occupied active sites and returned after undergoing heat exchange (τ > 0). Adsorption is an endothermic spontaneous process that results in a balance between entropic and enthalpic contributions. In such a reaction, ΔG°< 0, even with ΔH°> 0, the process occurs with an important increase in the entropy. The desorption was more efficient with ethanol and methanol than with HCl, NaOH, and NaCl owing to the dipole-dipole forces between the adsorbate and the alcohols. Additionally, the low desorption efficiency using acid, base, and salts can be attributed to competitive effects between the desorption agents and the active sites of the adsorbents.

Optimization of Sibipiruna activated carbon preparation by simplex-centroid mixture design for simultaneous adsorption of rhodamine B and metformin.

The present paper reports the application of augmented simplex-centroid mixture design to obtain a high BET surface area activated carbon using as reactants KOH, K2CO3 and K2C2O4. The optimum mixture composition was 2.51 g of KOH, 0.49 g of K2CO3 and absence of K2C2O4, generating an optimized AC (ACop) with SBET value equals to 1984 m2 g-1. The results herein obtained show that low amounts of K2CO3 can catalyze the pore development in the presence of KOH, increasing the surface area. Furthermore, the fractal dimensions of ACop are greater than 2.72, indicating the material has a complex pore structure with irregularities self-similar upon variations of resolution, as seen by SEM images. The TPD curves showed that the ACop has different oxygenated molecular fragments, which agrees with the pHPZC value (5.05). The ACop was applied in the adsorption of rhodamine B (RhB) and metformin (Met) in both binary and monocomponent systems. The simultaneous adsorption at 30 °C reveals that the adsorption capacity of RhB is 630.94 mg g-1, while for Met the value is 103.83 mg g-1.

Chlorella vulgaris growth in different biodigested vinasse concentrations: biomass, pigments and final composition.

Vinasse, an effluent generated during sugar and alcohol production, has great potential for soil and water pollution; however, it can be treated, used in biomass production and reused in sugarcane plantations. Thus, this work uses different types of biodigested vinasse to produce more biomass. The effect is the removal of ammonia nitrogen quickly and the end of the exponential growth phase of microalgae at different levels from the sixth day of cultivation. Among the concentrations used, the use of 50% biodigested vinasse showed the highest biomass concentration (255 mg L-1) after 10 days of growth, coinciding with the end of ammoniacal nitrogen availability and stabilization of effluent color removal. The addition of biodigested vinasse also provides an increase in Chlorophyll a (5.33 mg L-1) and b (4.66 mg L-1) levels, obtained on the sixth day with 40% of vinasse, as well as protein (40.50%) with 50% effluent. Therefore, with the obtained results we noticed the variation of the biomass composition according to the vinasse concentration and increase of the pigment concentration in the presence of the effluent with higher nutrient concentration. Thus, the higher concentration of vinasse was more productive of the cultivation of Chlorella vulgaris.

Early life exposure and its association with diseases in adulthood: review of longitudinal studies / Exposiciones tempranas en la vida y su asociación con enfermedades en la edad adulta: revisión de estudios longitudinales

Abstract Background: We describe the evidence of the effects of early life exposures on health and aging during adulthood. Methods: A narrative review of cohorts and systematic reviews of studies initiated early in life and followed up to adulthood was conducted. Results: Most studies were carried out in developed countries. The long-term effects of birth weight and, to a lesser extent, height at birth on chronic-degenerative diseases, functionality, bone, renal and respiratory pathology, and mortality have been consistent. Breastfeeding is associated with metabolic and cardiovascular diseases and functionality. Adiposity, bone pathophysiology, functionality in old age, and high blood pressure are associated with socioeconomic status at birth. Conclusions: Several exposures from intrauterine life to adolescence that exert discrete but significant effects on adult health have been consistently described. It is necessary to carry out these studies in developing countries.

Resumen Introducción: En este artículo se describe la evidencia acerca de los efectos de las exposiciones tempranas sobre la salud y el envejecimiento en la edad adulta. Métodos: Revisión narrativa de cohortes y revisiones sistemáticas de estudios iniciados en la vida temprana y seguidos hasta la edad adulta. Resultados: La mayoría de los estudios se realizaron en países desarrollados. Los efectos a largo plazo del peso al nacer, y en menor medida de la talla al nacer, en las enfermedades crónico-degenerativas, la funcionalidad, la fisiopatología ósea, renal y respiratoria, y la mortalidad, han sido consistentes. La lactancia materna se ha asociado con enfermedades metabólicas y cardiovasculares, y con la funcionalidad. La adiposidad, la fisiopatología ósea, la funcionalidad en la vejez y la hipertensión arterial están asociadas con el nivel socioeconómico al nacer. Conclusiones: Diferentes exposiciones desde la vida intrauterina hasta la adolescencia ejercen efectos discretos, pero significativos, sobre la salud de los adultos. Se requiere realizar estos estudios en las poblaciones que viven en países en desarrollo.

Early life exposure and its association with diseases in adulthood: review of longitudinal studies.

Background: We describe the evidence of the effects of early life exposures on health and aging during adulthood. Methods: A narrative review of cohorts and systematic reviews of studies initiated early in life and followed up to adulthood was conducted. Results: Most studies were carried out in developed countries. The long-term effects of birth weight and, to a lesser extent, height at birth on chronic-degenerative diseases, functionality, bone, renal and respiratory pathology, and mortality have been consistent. Breastfeeding is associated with metabolic and cardiovascular diseases and functionality. Adiposity, bone pathophysiology, functionality in old age, and high blood pressure are associated with socioeconomic status at birth. Conclusions: Several exposures from intrauterine life to adolescence that exert discrete but significant effects on adult health have been consistently described. It is necessary to carry out these studies in developing countries.

Introducción: En este artículo se describe la evidencia acerca de los efectos de las exposiciones tempranas sobre la salud y el envejecimiento en la edad adulta. Métodos: Revisión narrativa de cohortes y revisiones sistemáticas de estudios iniciados en la vida temprana y seguidos hasta la edad adulta. Resultados: La mayoría de los estudios se realizaron en países desarrollados. Los efectos a largo plazo del peso al nacer, y en menor medida de la talla al nacer, en las enfermedades crónico-degenerativas, la funcionalidad, la fisiopatología ósea, renal y respiratoria, y la mortalidad, han sido consistentes. La lactancia materna se ha asociado con enfermedades metabólicas y cardiovasculares, y con la funcionalidad. La adiposidad, la fisiopatología ósea, la funcionalidad en la vejez y la hipertensión arterial están asociadas con el nivel socioeconómico al nacer. Conclusiones: Diferentes exposiciones desde la vida intrauterina hasta la adolescencia ejercen efectos discretos, pero significativos, sobre la salud de los adultos. Se requiere realizar estos estudios en las poblaciones que viven en países en desarrollo.

Epigenetic variations due to nutritional status in early-life and its later impact on aging and disease.

Epigenetics refers to changes in gene function, not resulting from the primary DNA sequence, influenced by the environment. It provides a link between the molecular regulation of the genome and the environmental signals exposed during the life of individuals (including lifestyle, social behavior, development, and nutrition). Notably, early development (intrauterine or postnatal) is highly influenced by the adverse socioeconomic status that leads to malnutrition or obesity; these conditions induce changes over the fetal epigenetic programming and can be transferred by transgenerational inheritance, inducing alterations of the transcription of genes related to several metabolic and neurological processes. Moreover, obesity during pregnancy, and excessive gestational weight gain are associated with an increased risk of fatal pregnancy complications, and adverse cardio-metabolic, respiratory and cognitive-related outcomes of the future child. However, most of our knowledge in this field comes from experimental animal models, that partially resemble the nutritional effects of humans. In this context, nutritional effects implicated in historical famines represent valuable information about the transgenerational effects of undernutrition and stress. In the present review, we attempt to describe the most outstanding results from the most studied famines about the impact of malnutrition on the epigenome.

Prevalence of obesity and diabetes in the socioeconomic transition of rural Mayas of Yucatan from 1962 to 2000.

Background: The Mayas of the State of Yucatan in Mexico are the only aboriginal group with obesity and diabetes data before 1997. Objective: To analyze socioeconomic trends associated with the increase in obesity and diabetes seen in rural Yucatan from 1962 to 2000. Methods: Body weight, height and venous Fasting Blood Glucose (FBG) were measured in 263 rural Maya adults participating in a 2000 nutrition survey. Results: Diabetes (FBG > 125 mg/dL) and obesity (BMI ≥ 30 kg/m2) were 10.6% and 35.7%, respectively. These results contrast with those of a 1962 survey where diabetic prevalence was 2.3% and 0% in women and men respectively, with widespread adult pellagra and malnutrition. An important socioeconomic transition that took place in Yucatan during this lapse appeared to be associated to the obesity and diabetes increase. Conclusions: Rural Yucatan evolved from malnutrition conditions to high prevalence of obesity and diabetes in less than 40 years. This change was associated with the transition from an agroindustry-based economy, characterized by high-energy expenditure and low protein intake, to lower energy requirements of a Government-subsidized economy with larger food supply.

Adsorption and desorption cycles of reactive blue BF-5G dye in a bone char fixed-bed column.

In the textile industry, the amount of dye unfixed in fabrics is discarded with wastewaters. Effluents of this nature can be treated efficiently by adsorption on activated bone char, but the reuse of adsorbent is necessary for the technique to be economically feasible. Therefore, the objective of this work was to study the process of desorption of BF-5G blue dye from a bone char fixed-bed column. Solutions of sodium chloride, acetic acid and ethyl alcohol were tested as regenerating agents. Due to the hydrophobicity effect of organic solvent molecules, the highest desorption capacity was observed for ethyl alcohol solution, and the fixed bed was reused after six cycles of adsorption. The other solutions did not promote significant desorption. The results showed that adsorption of the dye involved irreversible interactions between adsorbate molecules and bone char. However, the use of acetic acid solution resulted in the neutralisation of some of the adsorbent surface charges, allowing the fixed bed to operate for a longer time in the second cycle than in the first.

Discretization-dependent model for weakly connected excitable media.

Pattern formation has been widely observed in extended chemical and biological processes. Although the biochemical systems are highly heterogeneous, homogenized continuum approaches formed by partial differential equations have been employed frequently. Such approaches are usually justified by the difference of scales between the heterogeneities and the characteristic spatial size of the patterns. Under different conditions, for example, under weak coupling, discrete models are more adequate. However, discrete models may be less manageable, for instance, in terms of numerical implementation and mesh generation, than the associated continuum models. Here we study a model to approach discreteness which permits the computer implementation on general unstructured meshes. The model is cast as a partial differential equation but with a parameter that depends not only on heterogeneities sizes, as in the case of quasicontinuum models, but also on the discretization mesh. Therefore, we refer to it as a discretization-dependent model. We validate the approach in a generic excitable media that simulates three different phenomena: the propagation of action membrane potential in cardiac tissue, in myelinated axons of neurons, and concentration waves in chemical microemulsions.

[Milk and dairy products: evidence and recommendations in health and disease]. / Leche y productos lácteos: evidencias y recomendaciones en la salud y la enfermedad.

El presente suplemento tiene como propósito mostrar el contexto y una guía clínica sobre el consumo y papel de la leche de vaca en la alimentación. El contenido considera el papel de la leche y productos lácteos en diferentes estados fisiológicos, etapas de vida y patologías. Se basa en la mejor evidencia científica disponible y está dirigido a profesionales de la salud de diferentes especialidades.

[Elder]. / Adulto mayor.

The aim of this review is to present scientific evidence on the biological, dietary, cultural and economic advantages of cow´s milk and dairy products intake in adults, with emphasis on the elderly. The role of milk and dairy products as part of the regular diet, as well as their contribution to a healthy diet for the aged population is described. The updated scientific references on the importance of milk and dairy products on the dietary management of the most prevalent diseases of the eldery -among these energy-protein malnutrition, sarcopenia, obesity, sarcopenic obesity, osteoporosis, diabetes and cardiovascular diseases- are presented.

Anthropometric characteristics and body composition in Mexican older adults: age and sex differences.

Anthropometric reference data for older adults, particularly for the oldest old, are still limited, especially in developing countries. The aim of the present study was to describe sex- and age-specific distributions of anthropometric measurements and body composition in Mexican older adults. The methods included in the present study were assessment of height, weight, BMI, calf circumference (CC), waist circumference (WC) and hip circumference (HC) as well as knee height in a sample of 8883 Mexican adults aged 60 years and above and the estimation of sex- and age-specific differences in these measures. Results of the study (n 7865, 54% women) showed that men are taller, have higher BMI, and larger WC than women, whereas women presented higher prevalence of obesity and adiposity. Overall prevalence of underweight was 2·3% in men and 4·0% in women, with increasing prevalence with advancing age. Significant differences were found by age group for weight, height, WC, HC, CC, BMI and knee height (P<0·001), but no significant differences in waist-hip circumference were observed. Significant differences between men and women were found in height, weight, circumferences, BMI and knee height (P<0·001). These results, which are consistent with studies of older adults in other countries, can be used for comparison with other Mexican samples including populations living in the USA and other countries with similar developmental and socio-economic conditions. This information can also be used as reference in clinical settings as a tool for detection of individuals at risk of either underweight or overweight and obesity.