Determination of biosorption mechanism in biomass of agave, using spectroscopic and microscopic techniques for the purification of contaminated water

[Abstract] Lead (Pb2+) and copper (Cu2+) are polluting metals due to their toxicity; however, the extraction of these metals is essential for economic development, so it is important to look for efficient and low-cost alternatives that can remove heavy metals from the various bodies of water. One of the alternatives used in this work is biosorption, for which an agroindustrial waste (epidermis from Agave atrovirens) was used to evaluate the affinity of removal of lead and copper in aqueous solutions; in addition, spectroscopy and microscopy techniques were used to elucidate and corroborate the removal and affinity capacity of the agave epidermis for both metals studied. The optimal pH value for the removal of both metals was 3. The adsorption isotherms yielded a qmax of 25.7 and 8.6 mg/g for lead and copper, respectively. Adjusting to the Langmuir-Freundlich model, the adsorption kinetics were pseudo-second order, and it was found that the equilibrium time was at 140 min. The spectroscopy and microscopy analyses corroborated the affinity between metals and functional groups of the agave, as well as with the elemental analysis, which reported 17.38% of lead and 4.25% of copper.[Resumen] El plomo (Pb2+) y el cobre (Cu2+) son metales contaminantes debido a su toxicidad; sin embargo, la extracción de estos metales es indispensable para el desarrollo económico, por lo que es importante buscar alternativas eficientes y de bajo costo que puedan remover metales pesados de los diversos cuerpos de agua. Una de las alternativas utilizadas en este trabajo es la biosorción, para la cual se utilizó un residuo agroindustrial (epidermis de Agave atrovirens), para evaluar la afinidad de remoción del plomo y cobre en soluciones acuosas; adicionalmente, se emplearon técnicas de espesctroscopía y microscopía que permitieron elucidar y corroborar la capacidad de remoción y afinidad que tuvo la epidermis de A. atrovirens para ambos metales estudiados. El valor óptimo de pH para la remoción de ambos metales fue 3. Las isotermas de adsorción arrojaron una qmax de 25.7 y 8.6 mg/g para el plomo y cobre, respectivamente. Ajustando al modelo de Langmuir-Freundlich, las cinéticas de adsorción resultaron de pseudo-segundo orden, se encontró que el tiempo de equilibrio es a los 140 min. El análisis espectroscópico y microscópico, corroboró la afinidad entre metales y grupos funcionales del agave, así como con el análisis elemental, el cual reportó 17.38% de plomo y 4.25% de cobre

Effect of algal food (Chlorella vulgaris) concentration and inoculation density on the competition among three planktonic Brachionidae (Rotifera: Monogononta)

Competitive outcomes among three rotifer species (Anuraeopsis fissa, Brachionus havanaensis and B. angularis) were quantified with different inoculation densities of two competing species at a time (0, 25, 50, 75 and100%) and using different algal (Chlorella vulgaris) densities (0.2 × 106 , 0.4 × 106 and 0.8 × 106 cells ml-1). In control cultures, when each species was grown alone, the population growth of rotifers increased with increasing food availability in the medium, but in mixed cultures, decreased with increasing proportion of the competing species. At low food level, compared to B. havanaensis, B. angularis had stronger negative impact on A. fissa. However, with increasing algal density, both species of Brachionus had similar but reduced impact on A. fissa. Population growth of B. havanaensis was more adversely affected by A. fissa than B. angularis at low and intermediate concentrations. At high food level, the impact of either A. fissa or B. angularis on the growth of B. havanaensis was similar. When grown alone, for a given food density, A. fissa was more numerically (4 to 6 times) abundant than the other two species. The rate of population increase (r) of rotifers increased with increasing food levels. Depending on the rotifer species and the test conditions, the r varied from -0.001 to 0.34 d-1. Results showed that the competitive outcome in the tested rotifers depended on the initial inoculation density of the competing species, the offered food concentration as well as the interaction of these two factors

Análisis distribucional de la abeja sin aguijón Scaptotrigona mexicana (Apidae: Meliponini) en México: Información de referencia para Veracruz

Objective: To obtain the specific geographic distribution based on the stingless bee Scaptotrigonna mexicana in Mexico and the state of Veracruz. Design/methodology/approach: 2202 coordinates of the Gbif database were filtered using a spocc database manager in the programming language R. Subsequently, 55 coordinates were obtained with which multiple models of maximum entropy were calibrated with nine predictive environmental variables of 19 initials in MaxEnt 3.3 .3 in ENMeval. The best performing model (AUC> 0.897 and AICc = 0) was reclassified into 5 categories of climatic suitability with the k-means clustering technique. Results: The specific geographic distribution pattern was obtained based on the climatic suitability of S. mexicana in Mexico and Veracruz, which was classified into five categories: very low or zero, low, medium, high and very high. Here we show two large zones of climatic suitability in Mexico for S. mexicana, which could be divided by the geographical barrier of the Isthmus of Tehuantepec, the first zone is located in the Sierra Norte de Puebla and Veracruz influenced by the Transversal Mountain System and the Sierra Madre Oriental and the second in the south of the country in the South Pacific Coast, Chiapas and Guatemala. The variables that determine this pattern is the seasonality of temperature and precipitation in the wettest and driest quarter. In Veracruz, 52 municipalities were divided into two large groups with potential for the exploitation and conservation of S. mexicana, the first in the North zone and the second in the Central Zone of the state. Findings/conclusions: The incorporation of environmental variables of greater spatial and temporal resolution is necessary to extend the accuracy of the pollination pattern of S. mexicana at local scales.Objetivo: Obtener la distribución geográfica específica con base en la abeja sin aguijón Scaptotrigona mexicana en México y el estado de Veracruz. Diseño/metodología/aproximación: Se filtraron 2202 coordenadas de la base de datos Gbif utilizando un gestor de base datos spocc en el lenguaje de programación R. Posteriormente se obtuvieron 55 coordenadas con las que se calibraron múltiples  modelos de máxima entropía con nueve variables ambientales predictivas de 19 iniciales en MaxEnt 3.3.3 en ENMeval. El modelo con mejor rendimiento (AUC> 0.897 y AICc = 0) se reclasificó en cinco categorías de idoneidad climática con la técnica de clustering k-means. Resultados: Se obtuvo el patrón de distribución geográfico específico basado en la idoneidad climática de S. mexicana en México y Veracruz, el cual se clasificó en 5 categorías: muy baja o nula, baja, media, alta y muy alta. Aquí mostramos dos grandes zonas de idoneidad climática en México para S. mexicana, las cuales podrían estar divididas por la barrera geográfica del Istmo de Tehuantepec, la primera zona se localiza en la Sierra Norte de Puebla y Veracruz influenciada por el Sistema Montañoso Transversal y la Sierra Madre Oriental y la segunda al sur de país en la Costa del Pacifico Sur, Chiapas y Guatemala. En Veracruz se encontraron 50 municipios divididos en dos grandes grupos con potencial para el aprovechamiento y conservación de S. mexicana, el primero en la zona Norte y el segundo en la Zona Centro del estado. Limitaciones del estudio/implicaciones: Es necesario la incorporación de variables ambientales de mayor resolución espacial y temporal, para ampliar la precisión del patrón de polinización de S. mexicana a escalas locales. Hallazgos/conclusiones: Existen dos grandes zonas de distribución de S. mexicana en en el país, localizadas en zona norte y la zona sur delimitados claramente por el Istmo de Tehuantepec. En Veracruz hay un total de 50 municipios distribuidos en la zona norte y centro que se benefician de forma potencial por el patrón de distribución S. mexicana, con medio, alto y muy alto para el aprovechamiento de la misma

Real-time intracellular temperature imaging using lanthanide-bearing polymeric micelles

Measurement of thermogenesis in individual cells is a remarkable challenge due to the complexity of the biochemical environment (such as pH and ionic strength) and to the rapid and yet not well-understood heat transfer mechanisms throughout the cell. Here, we present a unique system for intracellular temperature mapping in a fluorescence microscope (uncertainty of 0.2 K) using rationally designed luminescent Ln3+-bearing polymeric micellar probes (Ln = Sm, Eu) incubated in breast cancer MDA-MB468 cells. Two-dimensional (2D) thermal images recorded increasing the temperature of the cells culture medium between 296 and 304 K shows inhomogeneous intracellular temperature progressions up to ∼20 degrees and subcellular gradients of ∼5 degrees between the nucleolus and the rest of the cell, illustrating the thermogenic activity of the different organelles and highlighting the potential of this tool to study intracellular processes.publishe

Optimization of xylanase production by filamentous fungi in solid state fermentation and scale-up to horizontal tube bioreactor

Five microorganisms, namely Aspergillus niger CECT 2700, A. niger CECT 2915, A. niger CECT 2088, Aspergillus terreus CECT 2808, and Rhizopus stolonifer CECT 2344, were grown on corncob to produce cell wall polysaccharide-degrading enzymes, mainly xylanases, by solid-state fermentation (SSF). A. niger CECT 2700 produced the highest amount of xylanases of 504±7 U/g dry corncob (dcc) after 3 days of fermentation. The optimization of the culture broth (5.0 g/L NaNO3, 1.3 g/L (NH4)2SO4, 4.5 g/L KH2PO4, and 3 g/L yeast extract) and operational conditions (5 g of bed loading, using an initial substrate to moistening medium of 1:3.6 (w/v)) allowed increasing the predicted maximal xylanase activity up to 2,452.7 U/g dcc. However, different pretreatments of materials, including destarching, autoclaving, microwave, and alkaline treatments, were detrimental. Finally, the process was successfully established in a laboratory-scale horizontal tube biore- actor, achieving the highest xylanase activity (2,926 U/g dcc) at a flow rate of 0.2 L/min. The result showed an overall 5.8-fold increase in xylanase activity after optimization of culture media, operational conditions, and scale-up.We are grateful to the Spanish Ministry of Science and Innovation for the financial support of this work (project CTQ2011-28967), which has partial financial support from the FEDER funds of the European Union; to the Leonardo da Vinci Programme for founding the stay of Felisbela Oliveira in Vigo University; to MAEC-AECID (Spanish Government) for the financial support for Perez-Bibbins, B. and to Spanish Ministry of Education, Culture and Sports for Perez-Rodriguez's FPU; and to Solla E. and Mendez J. (CACTI-University of Vigo) for their excellent technical assistance in microscopy

Epidemiological trends of HIV/HCV coinfection in Spain, 2015-2019

Altres ajuts: Spanish AIDS Research Network; European Funding for Regional Development (FEDER).Objectives: We assessed the prevalence of anti-hepatitis C virus (HCV) antibodies and active HCV infection (HCV-RNA-positive) in people living with HIV (PLWH) in Spain in 2019 and compared the results with those of four similar studies performed during 2015-2018. Methods: The study was performed in 41 centres. Sample size was estimated for an accuracy of 1%. Patients were selected by random sampling with proportional allocation. Results: The reference population comprised 41 973 PLWH, and the sample size was 1325. HCV serostatus was known in 1316 PLWH (99.3%), of whom 376 (28.6%) were HCV antibody (Ab)-positive (78.7% were prior injection drug users); 29 were HCV-RNA-positive (2.2%). Of the 29 HCV-RNA-positive PLWH, infection was chronic in 24, it was acute/recent in one, and it was of unknown duration in four. Cirrhosis was present in 71 (5.4%) PLWH overall, three (10.3%) HCV-RNA-positive patients and 68 (23.4%) of those who cleared HCV after anti-HCV therapy (p = 0.04). The prevalence of anti-HCV antibodies decreased steadily from 37.7% in 2015 to 28.6% in 2019 (p < 0.001); the prevalence of active HCV infection decreased from 22.1% in 2015 to 2.2% in 2019 (p < 0.001). Uptake of anti-HCV treatment increased from 53.9% in 2015 to 95.0% in 2019 (p < 0.001). Conclusions: In Spain, the prevalence of active HCV infection among PLWH at the end of 2019 was 2.2%, i.e. 90.0% lower than in 2015. Increased exposure to DAAs was probably the main reason for this sharp reduction. Despite the high coverage of treatment with direct-acting antiviral agents, HCV-related cirrhosis remains significant in this population

Ten golden rules for optimal antibiotic use in hospital settings: the WARNING call to action

Antibiotics are recognized widely for their benefits when used appropriately. However, they are often used inappropriately despite the importance of responsible use within good clinical practice. Effective antibiotic treatment is an essential component of universal healthcare, and it is a global responsibility to ensure appropriate use. Currently, pharmaceutical companies have little incentive to develop new antibiotics due to scientific, regulatory, and financial barriers, further emphasizing the importance of appropriate antibiotic use. To address this issue, the Global Alliance for Infections in Surgery established an international multidisciplinary task force of 295 experts from 115 countries with different backgrounds. The task force developed a position statement called WARNING (Worldwide Antimicrobial Resistance National/International Network Group) aimed at raising awareness of antimicrobial resistance and improving antibiotic prescribing practices worldwide. The statement outlined is 10 axioms, or “golden rules,” for the appropriate use of antibiotics that all healthcare workers should consistently adhere in clinical practice