102 research outputs found

    Multi-technical approach for the characterization of polychrome decorative surfaces at Spanish Mission Churches in Nueva Vizcaya (Chihuahua, Mexico)

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    An interdisciplinary and multi-institutional group of science and art conservation specialists has provided new insight into the painting materials used in the polychrome walls and wooden ceilings in four seventeenth century Spanish colonial churches of Nueva Vizcaya (Chihuahua, Mexico). A multi-analytical study of the decorative surfaces was performed in situ using spectroscopic approaches (XRF, FORS), False Colour Infrared Reflectography – IRFC, as well as micro sampling (ATR-FTIR, LM, GC/MS). A survey of natural resources and study (ATR-FTIR, LM) was carried out to elucidate the natural occurrence of a select number of materials in the surrounding areas of the churches. The present paper presents a multi-analytical study and characterization of green, red-orange and black colour pigments and binders selected from the decorative surfaces. The aim of this study is to highlight relationships between local materials and those from the original polychrome ceilings, in order to understand the material and technological influences that converged in the Spanish colonial architecture of northern Mexico

    In vivo antimicrobial activity of silver nanoparticles produced via a green chemistry synthesis using Acacia rigidula as a reducing and capping agent

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    Introduction: One of the main issues in the medical field and clinical practice is the development of novel and effective treatments against infections caused by antibiotic-resistant bacteria. One avenue that has been approached to develop effective antimicrobials is the use of silver nanoparticles (Ag-NPs), since they have been found to exhibit an efficient and wide spectrum of antimicrobial properties. Among the main drawbacks of using Ag-NPs are their potential cytotoxicity against eukaryotic cells and the latent environmental toxicity of their synthesis methods. Therefore, diverse green synthesis methods, which involve the use of environmentally friendly plant extracts as reductive and capping agents, have become attractive to synthesize Ag-NPs that exhibit antimicrobial effects against resistant bacteria at concentrations below toxicity thresholds for eukaryotic cells. Purpose: In this study, we report a green one-pot synthesis method that uses Acacia rigidula extract as a reducing and capping agent, to produce Ag-NPs with applications as therapeutic agents to treat infections in vivo. Materials and methods: The Ag-NPs were characterized using transmission electron microscopy (TEM), high-resolution TEM, selected area electron diffraction, energy-dispersive spectroscopy, ultraviolet–visible, and Fourier transform infrared. Results: We show that Ag-NPs are spherical with a narrow size distribution. The Ag-NPs show antimicrobial activities in vitro against Gram-negative (Escherichia coli, Pseudomonas aeruginosa, and a clinical multidrug-resistant strain of P. aeruginosa) and Gram-positive (Bacillus subtilis) bacteria. Moreover, antimicrobial effects of the Ag-NPs, against a resistant P. aeruginosa clinical strain, were tested in a murine skin infection model. The results demonstrate that the Ag-NPs reported in this work are capable of eradicating pathogenic resistant bacteria in an infection in vivo. In addition, skin, liver, and kidney damage profiles were monitored in the murine infection model, and the results demonstrate that Ag-NPs can be used safely as therapeutic agents in animal models. Conclusion: Together, these results suggest the potential use of Ag-NPs, synthesized by green chemistry methods, as therapeutic agents against infections caused by resistant and nonresistant strains. Keywords: silver nanoparticles, green synthesis, in vitro antibacterial activity, in vivo antibacterial activity, skin infection, toxicological stud

    Clonal chromosomal mosaicism and loss of chromosome Y in elderly men increase vulnerability for SARS-CoV-2

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    The pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2, COVID-19) had an estimated overall case fatality ratio of 1.38% (pre-vaccination), being 53% higher in males and increasing exponentially with age. Among 9578 individuals diagnosed with COVID-19 in the SCOURGE study, we found 133 cases (1.42%) with detectable clonal mosaicism for chromosome alterations (mCA) and 226 males (5.08%) with acquired loss of chromosome Y (LOY). Individuals with clonal mosaic events (mCA and/or LOY) showed a 54% increase in the risk of COVID-19 lethality. LOY is associated with transcriptomic biomarkers of immune dysfunction, pro-coagulation activity and cardiovascular risk. Interferon-induced genes involved in the initial immune response to SARS-CoV-2 are also down-regulated in LOY. Thus, mCA and LOY underlie at least part of the sex-biased severity and mortality of COVID-19 in aging patients. Given its potential therapeutic and prognostic relevance, evaluation of clonal mosaicism should be implemented as biomarker of COVID-19 severity in elderly people. Among 9578 individuals diagnosed with COVID-19 in the SCOURGE study, individuals with clonal mosaic events (clonal mosaicism for chromosome alterations and/or loss of chromosome Y) showed an increased risk of COVID-19 lethality

    4to. Congreso Internacional de Ciencia, Tecnología e Innovación para la Sociedad. Memoria académica

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    Este volumen acoge la memoria académica de la Cuarta edición del Congreso Internacional de Ciencia, Tecnología e Innovación para la Sociedad, CITIS 2017, desarrollado entre el 29 de noviembre y el 1 de diciembre de 2017 y organizado por la Universidad Politécnica Salesiana (UPS) en su sede de Guayaquil. El Congreso ofreció un espacio para la presentación, difusión e intercambio de importantes investigaciones nacionales e internacionales ante la comunidad universitaria que se dio cita en el encuentro. El uso de herramientas tecnológicas para la gestión de los trabajos de investigación como la plataforma Open Conference Systems y la web de presentación del Congreso http://citis.blog.ups.edu.ec/, hicieron de CITIS 2017 un verdadero referente entre los congresos que se desarrollaron en el país. La preocupación de nuestra Universidad, de presentar espacios que ayuden a generar nuevos y mejores cambios en la dimensión humana y social de nuestro entorno, hace que se persiga en cada edición del evento la presentación de trabajos con calidad creciente en cuanto a su producción científica. Quienes estuvimos al frente de la organización, dejamos plasmado en estas memorias académicas el intenso y prolífico trabajo de los días de realización del Congreso Internacional de Ciencia, Tecnología e Innovación para la Sociedad al alcance de todos y todas

    Reducing the environmental impact of surgery on a global scale: systematic review and co-prioritization with healthcare workers in 132 countries

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    Abstract Background Healthcare cannot achieve net-zero carbon without addressing operating theatres. The aim of this study was to prioritize feasible interventions to reduce the environmental impact of operating theatres. Methods This study adopted a four-phase Delphi consensus co-prioritization methodology. In phase 1, a systematic review of published interventions and global consultation of perioperative healthcare professionals were used to longlist interventions. In phase 2, iterative thematic analysis consolidated comparable interventions into a shortlist. In phase 3, the shortlist was co-prioritized based on patient and clinician views on acceptability, feasibility, and safety. In phase 4, ranked lists of interventions were presented by their relevance to high-income countries and low–middle-income countries. Results In phase 1, 43 interventions were identified, which had low uptake in practice according to 3042 professionals globally. In phase 2, a shortlist of 15 intervention domains was generated. In phase 3, interventions were deemed acceptable for more than 90 per cent of patients except for reducing general anaesthesia (84 per cent) and re-sterilization of ‘single-use’ consumables (86 per cent). In phase 4, the top three shortlisted interventions for high-income countries were: introducing recycling; reducing use of anaesthetic gases; and appropriate clinical waste processing. In phase 4, the top three shortlisted interventions for low–middle-income countries were: introducing reusable surgical devices; reducing use of consumables; and reducing the use of general anaesthesia. Conclusion This is a step toward environmentally sustainable operating environments with actionable interventions applicable to both high– and low–middle–income countries

    Estudio y diseño de transmisores y receptores para redes umts

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    El presente trabajo se basa el estudio de la arquitectura y el diseño que se requiere para la Transmisión y Recepción dentro de una red UMTS (Universal Mobile Telecommunication System) y las distintas etapas que en que éstas intervienen. UMTS busca extender las actuales tecnologías móviles, inalámbricas y satelitales proporcionando mayor capacidad, posibilidades de transmisión de datos y una gama de servicios mucho más extensa, usando un innovador programa de acceso radioeléctrico y una red principal mejorada. Este proyecto consta de 4 capítulos que se describen brevemente a continuación: En el capítulo 1 se describe la estructura de una red UMTS y sus principales elementos que la conforman. En el capítulo 2 se describen las técnicas de modulación que se utilizan para el enlace de subida y bajada en la transmisión y los principios básicos que hay detrás de estas modulaciones. El capítulo 3 analiza las distintas estrategias de recepción multiusuario así como establecer una comparación de características técnicas con tecnologías anteriores como 3G, CDMA y WCDMA. Por último en el capítulo 4 se realizara el monitoreo y seguimiento en tiempo real en la transmisión y recepción de una señal UMTS-HSDPA dentro una red UMTS, y analizar sus principales parámetros

    Nopal mucilage as hydration agent for quicklime; extraction methods

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    The main objective of this research is to select an extraction method of nopal mucilage to be used as a hydration agent at a suitable concentration for slaking quicklime in order to obtain lime putties with better rheological and mechanical properties. An experimental phase was performed where different extraction methods to obtain nopal mucilage were tested. This made it possible to classify them into two groups: methods that require water to get the mucilage, and methods that obtain the mucilage directly from the plant. Galacturonic acid present in mucilage composition seemed to be the main cause of the chemical interaction between lime and mucilage. As a result, mucilage that presented the largest amount of galacturonic acid according to acid base titration curves was chosen as the best one to work with. It was concluded that the amount of galacturonic acid present in mucilage is not influenced by rising temperature and constant stirring during its extraction process, nor the nopal species or cladodes dimension. Furthermore, it was observed that mucilage viscosity obtained through the different extraction methods has a strong impact on the slaking process behavior and in the consistency of the resulting putties.Esta investigación tiene por objeto la elección de un método de extracción de mucílago de nopal para emplear a este último como agente hidratador de cal para producir cal apagada que confiera mejores propiedades reológicas y mecánicas a las pastas de cal apagada. En esta etapa se desarrolló una fase experimental que incluyó distintos métodos de extracción de mucílago de nopal siendo posible clasificarlos en dos grupos: los que emplean agua en su procedimiento y aquellos que obtienen el mucílago directamente de la planta sin adicionar otra sustancia. El ácido galacturónico parece ser la sustancia responsable de la interacción química entre el mucílago y la cal, por lo tanto, el mucilago que presentó la mayor cantidad de ácido galacturonico de acuerdo a las curvas de valoración ácido base, fue elegido. Pudo concluirse que la cantidad de ácido galacturónico presente en el mucílago de nopal no está influenciada por factores de elevación de la temperatura y agitación durante el método de extracción, ni por la especie y el tamaño de sus cladodios. Adicionalmente fue observado que la viscosidad del mucílago obtenido de los diferentes métodos de extracción tiene un impacto importante en el comportamiento del proceso de hidratación de cal y en la consistencia de las pastas de cal

    Outcomes of meso-Rex bypass for prehepatic portal hypertension in pediatric patients

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    Portal hypertension in pediatric patients is often associated with prehepatic portal hypertension (PHPH), frequently linked to thrombosis and cavernomatous degeneration of the portal vein (CDVP). This study evaluates the efficacy of the MesoRexBypass (MRB) in managing PHPH and associated thrombosis. Methods: A retrospective prognostic cohort design was employed to analyze the clinical outcomes of nine pediatric patients who underwent MRB between 2020 and 2022. Clinical and surgical variables were examined, including graft type, surgical time, and complications. Postoperative follow-up confirmed MRB functionality. Results: The MRB proved highly successful, with improved clinical parameters observed in all patients. Significant reductions in gastrointestinal bleeding, esophageal varices, and hypertensive gastropathy were observed postoperatively. Thrombocytopenia and liver enzyme levels showed substantial improvement, indicating enhanced liver function and amelioration of hypersplenism. The MRB's adaptability was demonstrated using autologous grafts and various graft sources.One patient experienced shunt thrombosis, another experienced minor gastrointestinal bleeding, and another died. The MRB exhibited a high success rate and few complications. Conclusion: The MRB is an effective and versatile surgical technique for managing PHPH in pediatric patients. This study emphasizes its promising outcomes and suggests its potential for enhancing treatment approaches and quality of life in this patient population. Further research with larger cohorts is needed to strengthen the evidence presented. The MRB holds promise as a valuable addition to the management of PHPH in children. Level of Evidence IV

    Insights from a retrospective study: an understanding of pediatric colorectal carcinoma

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    Abstract Pediatric colorectal cancer, comprising just 1% of childhood cancers, has surged among young individuals, underscoring its significant health impact. Diagnostic challenges arise from atypical presentation and nonspecific symptoms in 90% of cases, leading to delayed detection in 19%. Methods A 2-year retrospective study of pediatric colorectal carcinoma cases was conducted across a specialized surgical pediatric center. Data were gathered, including age, symptoms, diagnostics, treatments, and outcomes. Results Six colorectal carcinoma cases (median age, 16) were documented, mainly in males (66%). Predominant histological types included mucinous adenocarcinoma and signet ring cell carcinoma. Metastasis was present in all cases, with symptoms including hematochezia (83%), abdominal pain (100%), weight loss (66%), and anemia (100%). Diagnosis often faced misidentification, fostering disease progression and metastasis. Various diagnostic and treatment modalities were employed, including surgery and neo-adjuvant or adjuvant chemotherapy. Conclusion Swift detection and intervention for pediatric colorectal carcinoma are pivotal. Efficient diagnostics and heightened awareness among medical professionals and the public are imperative. Early surgical intervention remains a cornerstone, especially for patients with pertinent family histories and characteristic symptoms. Tailored guidelines for pediatric patients are needed to enhance outcomes and survival
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