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The present study aims to analyze the interaction between Rhodotorula toruloides and magnetic nanoparticles and evaluate their effect on carotenoid production. The manganese ferrite nanoparticles were synthesized without chitosan (MnFe2O4) and chitosan coating (MnFe2O4-CS) by the co-precipitation method assisted by hydrothermal treatment. XRD (X-ray diffraction), Magnetometry, Dynamic Light Scattering (DLS) and FTIR (Fourier-Transform Infrared Spectroscopy), are used to characterize the magnetic nanoparticles. The crystallite size of MnFe2O4 was 16 nm for MnFe2O4 and 20 nm for MnFe2O4-CS. The magnetic saturation of MnFe2O4-CS was lower (39.6 ± 0.6 emu/g) than the same MnFe2O4 nanoparticles (42.7 ± 0.3 emu/g), which was attributed to the chitosan fraction presence. The MnFe2O4-CS FTIR spectra revealed the presence of the characteristic chitosan bands. DLS demonstrated that the average hydrodynamic diameters were 344 nm for MnFe2O4 and 167 nm for MnFe2O4-CS. A kinetic study of cell immobilization performed with their precipitation with a magnet demonstrated that interaction between magnetic nanoparticles and R. toruloides was characterized by an equilibrium time of 2 h. The adsorption isotherm models (Langmuir and Freundlich) were fitted to the experimental values. The trypan blue assay was used for cell viability assessment. The carotenoid production increased to 256.2 ± 6.1 µg/g dry mass at 2.0 mg/mL MnFe2O4-CS. The use of MnFe2O4-CS to stimulate carotenoid yeast production and the magnetic separation of biomass are promising nanobiotechnological alternatives. Magnetic cell immobilization is a perspective technique for obtaining cell metabolites.

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Background: Hemophagocytic syndrome or hemophagocytic lymphohistiocytosis (HL) is an immune hyperactivation of multifactorial etiology, characterized by excessive activation of lymphocytes and macrophages, as well as numerous pro-inflammatory cytokines. It has a non-specific and highly variable clinical presentation, with splenomegaly being one of the clinical manifestations. Due to its nature, it can manifest during childhood or adult life, which is why it is a disease of diagnostic and therapeutic complexity. Clinical case: 38-year-old male patient without comorbidities, who presented with abdominal pain, choluria, fever > 38 °C and diaphoresis of more than 10 days of evolution. A bone marrow aspirate was performed as part of the diagnostic approach with data compatible with hemophagocytosis and cytopenias. The immunosuppressive management did not show the expected response, which is why an open splenectomy was performed as the last therapeutic option with adequate hematological control. A documentary review of the disease was carried out, and of the therapeutic options, emphasizing surgical management in case of refractoriness to medical treatment. Conclusions: Splenectomy increases the overall survival rate and the time free of HL progression, even though there are still no studies to determine with certainty the ideal time to perform a splenectomy in patients with pancytopenia without splenomegaly who suffer from hemophagocytic syndrome.

Introducción: el síndrome hemofagocítico o linfohistiocitosis hemofagocítica (LH) es una hiperactivación inmune de etiología multifactorial, caracterizada por activación excesiva de linfocitos y macrófagos, así como por numerosas citocinas proinflamatorias. Tiene una presentación clínica poco específica y muy variable, y la esplenomegalia es una de las manifestaciones clínicas. Debido a su naturaleza puede manifestarse durante la infancia o la vida adulta, por lo que es una enfermedad de complejidad diagnóstica y terapéutica. Caso clínico: paciente del sexo masculino de 38 años sin comorbilidades, quien presentó dolor abdominal, coluria, fiebre > 38 °C y diaforesis de más de 10 días de evolución. Se le hizo aspirado de médula ósea como parte del abordaje diagnóstico con datos compatibles con hemofagocitosis y citopenias. El manejo inmunosupresor no mostró la respuesta esperada, por lo que se hizo esplenectomía abierta como última opción terapéutica con adecuado control hematológico. Se hizo una revisión documental de la enfermedad y de las opciones terapéuticas con énfasis en el manejo quirúrgico en caso de refractariedad al tratamiento médico. Conclusiones: la esplenectomía aumenta la tasa de supervivencia general y el tiempo libre de progresión de la LH, aunque no hay todavía estudios para determinar con certeza el tiempo ideal para hacer una esplenectomía en pacientes con pancitopenia sin esplenomegalia que padezcan síndrome hemofagocítico.

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Due to its extensive use as a painkiller, anti-inflammatory, and immune modulatory agent, as well as its effectiveness in treating severe COVID-19, dexamethasone, a synthetic glucocorticoid, has gained attention not only for its impact on public health but also for its environmental implications. Various studies have reported its presence in aquatic environments, including urban waters, surface samples, sediments, drinking water, and wastewater effluents. However, limited information is available regarding its toxic effects on nontarget aquatic organisms. Therefore, this study aimed to investigate the mechanism of toxicity underlying dexamethasone-induced brain damage in the bioindicator Danio rerio following long-term exposure. Adult zebrafish were treated with environmentally relevant concentrations of dexamethasone (20, 40, and 60 ng L-1) for 28 days. To elucidate the possible mechanisms involved in the toxicity of the pharmaceutical compound, we conducted a behavioral test battery (Novel Tank and Light and Dark tests), oxidative stress biomarkers, acetylcholinesterase enzyme activity quantification, histopathological analysis, and gene expression analysis using qRT-PCR (p53, bcl-2, bax, caspase-3, nrf1, and nrf2).The results revealed that the pharmaceutical compound could produce anxiety-like symptoms, increase the oxidative-induced stress response, decrease the activity of acetylcholinesterase enzyme, and cause histopathological alterations, including perineuronal vacuolization, granular and molecular layers deterioration, cell swallowing and intracellular spaces. The expression of genes involved in the apoptotic process (p53, bax, and casp-3) and antioxidant defense (nrf1 and nrf2) was upregulated in response to oxidative damage, while the expression of the anti-apoptotic gene bcl-2 was down-regulated indicating that the environmental presence of dexamethasone may pose a threat to wildlife and human health.

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Bone tissue engineering is a promising alternative to repair wounds caused by cellular or physical accidents that humans face daily. In this sense, the search for new graphene oxide (GO) nanofillers related to their degree of oxidation is born as an alternative bioactive component in forming new scaffolds. In the present study, three different GOs were synthesized with varying degrees of oxidation and studied chemically and tissue-wise. The oxidation degree was determined through infrared (FTIR), X-ray diffraction (XRD), X-ray photoelectron (XPS), and Raman spectroscopy (RS). The morphology of the samples was analyzed using scanning electron microscopy (SEM). The oxygen content was deeply described using the deconvolution of RS and XPS techniques. The latter represents the oxidation degree for each of the samples and the formation of new bonds promoted by the graphitization of the material. In the RS, two characteristic bands were observed according to the degree of oxidation and the degree of graphitization of the material represented in bands D and G with different relative intensities, suggesting that the samples have different crystallite sizes. This size was described using the Tuinstra-Koenig model, ranging between 18.7 and 25.1 nm. Finally, the bone neoformation observed in the cranial defects of critical size indicates that the F1 and F2 samples, besides being compatible and resorbable, acted as a bridge for bone healing through regeneration. This promoted healing by restoring bone and tissue structure without triggering a strong immune response.

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BACKGROUND: Polymeric electrospun mats have been used as scaffolds in tissue engineering for the development of novel materials due to its characteristics. The usage of synthetic materials has gone in decline due to environmental problems associated with their synthesis and waste disposal. Biomaterials such as biopolymers have been used recently due to good compatibility on biological applications and sustainability. OBJECTIVE: The purpose of this work is to obtain novel materials based on synthetic and natural polymers for applications on tissue engineering. METHODS: Aloe vera mucilage was obtained, chemically characterized, and used as an active compound contained in electrospun mats. Polymeric scaffolds were obtained in single, coaxial and tri-layer structures, characterized and evaluated in cell culture. RESULTS: Mucilage loaded electrospun fibers showed good compatibility due to formation of hydrogen bonds between polymers and biomolecules from its structure, evidenced by FTIR spectra and thermal properties. Cell viability test showed that most of the obtained mats result on viability higher than 75%, resulting in nontoxic materials, ready to be used on scaffolding applications. CONCLUSION: Mucilage containing fibers resulted on materials with potential use on scaffolding applications due to their mechanical performance and cell viability results.

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Gelatinous zooplankton constitutes a polyphyletic group with a convergent evolutionary history and poorly known biogeographical patterns. In the Gulf of Mexico, a region with complex geological, hydrological, and biotic histories, the study of this group has been limited to taxonomical and ecological aspects. In this study, we implemented a track analysis to identify distributional patterns of gelatinous zooplankton in the Gulf of Mexico and adjacent waters based on a dataset of 6067 occurrence records corresponding to Hydrozoa, Scyphozoa, Cubozoa, Ctenophora, Chaetognatha, Thaliacea, and Appendicularia. Information was compiled from the Global Biodiversity Facility Information (GBIF) and Ocean Biodiversity Information System (OBIS) databases and peer-reviewed literature. Individual tracks were constructed by joining the minimum distance between the occurrence localities of each taxon using a minimum spanning tree algorithm. We identified generalized tracks using parsimony analysis of endemicity with progressive character elimination (PAE-PCE). The areas where different generalized tracks overlapped were considered to represent panbiogeographical nodes. Seven generalized tracks (two with nested patterns) and six panbiogeographical nodes were recognized, mainly in neritic zones. The distributional patterns of gelatinous zooplankton allowed us to identify four biogeographic areas, supporting previously proposed biogeographic schemes. Gelatinous zooplankton in the Gulf of Mexico showed a convergent spatial distribution that can be explained by vicariant and dispersal events. The historical biogeography of the gelatinous biotas of the Gulf of Mexico has been little studied compared to ecological approaches, and the lack of integrative studies considering historical patterns is evident. This type of research is fundamental to understanding the evolutionary history of natural resources from a spatial perspective, identifying sites of biodiversity and endemism, and establishing a biogeographic baseline of the region for further studies.

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Sulfuric acid anodizing assisted by a hydrothermal sealing with inhibitors [Ce3+-Mo6+] was used to prevent pitting corrosion on spray-deposited hypereutectic Al-Si alloy (A390). An investigation concerning the evaluation of pitting corrosion resistance on the anodic oxide thin film with ions incorporated was carried out in NaCl solution using electrochemical measurements (i.e., potentiodynamic polarization and electrochemical impedance spectroscopy, EIS). The influence of Si phase morphology and size on the growth mechanism of an anodic oxide film was characterized by scanning electron microscopy (SEM) and X-ray diffraction (XRD). The results were then compared with those for its equivalent IM390 alloy (Al-17Si-4.5Cu-0.6Mg) produced through a conventional process ingot metallurgy, IM. The electrochemical findings indicate that sulfuric acid anodizing followed by a simple hot water sealing treatment was ineffective. In this manner, an intense attack was localized by pitting corrosion that occurred on the anodic oxide film in less than three days, as denoted by characteristic changes in the EIS spectra at the lowest frequencies. Improved results were achieved for Ce-Mo surface modification, which can provide better corrosion resistance on the aluminum alloys because no signs of pits were observed during the corrosion testing.

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When the cocoa pod husk (CPH) is used and processed, two types of flour were obtained and can be differentiated by particle size, fine flour (FFCH), and coarse flour (CFCH) and can be used as a possible reinforcement for the development of bio-based composite materials. Each flour was obtained from chopping, drying by forced convection, milling by blades, and sieving using the 100 mesh/bottom according to the Tyler series. Their physicochemical, thermal, and structural characterization made it possible to identify the lower presence of lignin and higher proportions of cellulose and pectin in FFCH. Based on the properties identified in FFCH, it was included in the processing of thermoplastic starch (TPS) from the plantain pulp (Musa paradisiaca) and its respective bio-based composite material using plantain peel short fiber (PPSF) as a reinforcing agent using the following sequence of processing techniques: extrusion, internal mixing, and compression molding. The influence of FFCH contributed to the increase in ultimate tensile strength (7.59 MPa) and higher matrix-reinforcement interaction when obtaining the freshly processed composite material (day 0) when compared to the bio-based composite material with higher FCP content (30%) in the absence of FFCH. As for the disadvantages of FFCH, reduced thermal stability (323.57 to 300.47 °C) and losses in ultimate tensile strength (0.73 MPa) and modulus of elasticity (142.53 to 26.17 MPa) during storage progress were identified. In the case of TPS, the strengthening action of FFCH was not evident. Finally, the use of CFCH was not considered for the elaboration of the bio-based composite material because it reached a higher lignin content than FFCH, which was expected to decrease its affinity with the TPS matrix, resulting in lower mechanical properties in the material.

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This study investigates the occurrence and characteristics of macroplastic and polymer microparticles in the Urias coastal lagoon's beach sediments, in northwest Mexico. Coastal lagoons, productive and vulnerable ecosystems, are impacted significantly by anthropogenic activities, leadings to their pollution by various contaminants, including plastics. Our research involved sampling sediments from four sites within the lagoon that were influenced by different human activities such as fishing, aquaculture, thermoelectric power plant operations, industrial operations, and domestic wastewater discharge. Our methodology included collecting macroplastics and beach sediment samples, followed by laboratory analyses to identify the plastic debris' size, shape, color, and chemical composition. The results indicated a notable presence of macroplastic items (144), predominantly bags, styrofoam, and caps made of polyethylene (PE), polypropylene (PP), and polyethylene terephthalate (PET). The polymer microparticles were mainly fibers, with cotton and polyester as the most common polymers, suggesting a significant contribution from clothing-related waste. The dominant colors of the microparticles were blue and transparent. High densities were observed in areas with slower water exchange. Our findings highlight the urgent need for better waste management practices to mitigate plastic pollution in coastal lagoons, preserving their ecological and economic functions.

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Objective: The objective is to expose the cardiovascular alterations in patients diagnosed with pediatric inflammatory multisystem syndrome (PIMS) associated with COVID-19 during the SARS-CoV-2 pandemic, in order to understand the disease, its evolution, and optimal management upon diagnosis. Method: Retrospective, observational, cross-sectional analytical study of patients diagnosed with PIMS according to the criteria of the World Health Organization at the National Institute of Pediatrics, from March 2020 to December 2021. Results: During the study period, 77 patients with PIMS were diagnosed. The results showed correlation between the shock state and alteration of laboratory markers (platelets 144217.29 ± 139321.6 µL [p < 0.001], procalcitonin 27.37 ± 38.37 ng/ml [p = 0.05] and ferritin 1937.87 ± 2562.63 [p < 0.001]). The ventricular function in patients with shock was significantly lower compared to those without shock (49.6 ± 9.1% vs. 58.1 ± 8.4 %; t-Student p < 0.001), as well as injury to the left coronary artery (p = 0.02). There is a correlation between NT-proBNP and ventricular dysfunction (Kruskal-Wallis p = 0.007). Statistical significance was found in the association between death, elevation of inflammatory markers and ventricular dysfunction (p < 0.001). Conclusions: The cardiovascular alterations observed, in order of frequency, were pericardial effusion (25.7%), myocarditis (15%), mild ventricular dysfunction (13.5%) and small coronary aneurysm with predominance of the left coronary artery and the anterior descending one.

Objetivo: Exponer las alteraciones cardiovasculares en los pacientes diagnosticados con síndrome inflamatorio multisistémico pediátrico (PIMS) asociado a COVID-19 durante la pandemia por SARS-CoV-2 con el fin de comprender la enfermedad, su evolución y el manejo óptimo al diagnóstico. Método: Estudio retrospectivo, observacional, transversal y analítico de pacientes con diagnóstico de PIMS de acuerdo con los criterios de la Organización Mundial de la Salud en el Instituto Nacional de Pediatría, de marzo de 2020 a diciembre de 2021. Resultados: Durante el periodo de estudio se diagnosticaron 77 pacientes con PIMS. Los resultados demostraron una correlación entre el estado de choque y la alteración de los marcadores de laboratorio (plaquetas 144217.29 ± 139321.6 µl [p < 0.001], procalcitonina 27.37 ± 38.37 ng/ml [p = 0.05] y ferritina 1937.87 ± 2562.63 [p < 0.001]). La función ventricular en los pacientes con choque se registró significativamente menor en comparación con aquellos sin choque (49.6 ± 9.1 % vs. 58.1 ± 8.4 %; t de Student p < 0.001), así como lesión en la arteria coronaria izquierda (p = 0.02). Existe una correlación entre el NT-proBNP y la disfunción ventricular (Kruskal-Wallis p = 0.007). Se encontró significancia estadística en la asociación entre fallecimiento, elevación de los marcadores inflamatorios y disfunción ventricular (p < 0.001). Conclusiones: Las alteraciones cardiovasculares observadas fueron, en orden de frecuencia, derrame pericárdico (25.7%), miocarditis (15%), disfunción ventricular leve (13.5%) y aneurisma pequeño coronario con predominio de la arteria coronaria izquierda y la descendente anterior.

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