Repositorio académico de acceso abierto (Univ. Autonóma de Chile)
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MicroRNAs as Potential Biomarkers of Environmental Exposure to Polycyclic Aromatic Hydrocarbons and Their Link with Inflammation and Lung Cancer
No full textExposure to atmospheric air pollution containing volatile organic compounds such as polycyclic aromatic hydrocarbons (PAHs) has been shown to be a risk factor in the induction of lung inflammation and the initiation and progression of lung cancer. MicroRNAs (miRNAs) are small single-stranded non-coding RNA molecules of ~20–22 nucleotides that regulate different physiological processes, and their altered expression is implicated in various pathophysiological conditions. Recent studies have shown that the regulation of gene expression of miRNAs can be affected in diseases associated with outdoor air pollution, meaning they could also be useful as biomarkers of exposure to environmental pollution. In this article, we review the published evidence on miRNAs in relation to exposure to PAH pollution and discuss the possible mechanisms that may link these compounds with the expression of miRNAs. © 2023 by the authors.DIUAV, (03-2022); VVIPUCT, (2023FIAS-PL-03, VIPUCT-2022REG-NG-01); Vicerrectoría de Investigación y Postgrado; Universidad Autónoma de Coahuila, UAdeC; Universidad Católica de Temuco, UCTUniversidad Autónoma de Chil
ESOL teacher educators’ learning initiatives and perceived learning needs: still a pending task
No full textEven though international research has offered a rich account of teacher educators’ professional learning, it has overlooked the implications of the disciplines they teach for their professional learning engagement. Therefore, it is timely to examine teacher educators from different fields of expertise to offer a more specific and subject-related understanding of their professional learning involvement. This study investigates the initiatives that Chilean university-based ESOL teacher educators engage in to continue learning and their perceived professional learning needs. Data are drawn from a national web-based survey and a focus group. The results suggest that individual formal learning opportunities that are highly valued, and sometimes prescribed, by higher education institutions are predominant. Their professional learning needs, however, relate mainly to promoting collaborative peer-learning, advancing knowledge about diversity in the classroom and technology literacy, and enhancing their research skills and practice in language teaching. This study highlights the importance of identifying these needs as a foundation to design learning opportunities that meet the demands of the profession and the particularities of each discipline. Recommendations to enhance their continuous education towards a view of professionalism that recognises their ability to manifest ideas and agency to effect change are discussed. © 2022 The Author(s). Published by Informa UK Limited, trading as Taylor & Francis Group.Agency Nacional de Investigacion y Desarrollo/National Research and Development Agency, (72190352); Agencia Nacional de Investigación y Desarrollo, ANIDUniversidad Autónoma de Chil
The Use of Human Sterilized Crushed Tooth Particles Compared with BTCP Biomaterial and Empty Defects in Bone Formation inside Critical Rabbit Calvaria Sites
No full textThis study aimed to assess the bone regeneration of critical-size defects in rabbit calvaria filled with freshly crushed extracted teeth, comparing them with BTCP biomaterial and empty sites. Materials and methods: Twenty-one female New Zealand rabbits were used in this study. Two critical-size defects 6 mm in size were created in the skull bone, each with a 3 mm separation between them. Three experimental groups were evaluated: Group A (human sterilized crushed teeth granules alone), Group B (Bioner Bone, Bioner Sitemas Implantológicos), and Group C (unfilled defects). The animals were sacrificed at 4 and 8 weeks. Evaluation of the samples involved histological and histomorphometric analyses with radiographic evaluation. The histological evaluation showed a higher volume reduction in Group A compared with Group B (p < 0.05) and Control. Group A showed the highest values for cortical closure and bone formation around the particles, followed by Group B and Group C (p < 0.05). Within the limitations of this animal study, we can conclude that the use of human tooth particles leads to increased bone formation and reduced connective tissue in critical-size defects in rabbit calvaria when compared to BTCP biomaterial. The calvarial model is a robust base for the evaluation of different biomaterials. © 2023 by the authors.Universidad Autónoma de Chil
A mechanothermal approach for the synthesis of Fe3O4 nanoparticles as dopant on mesoporous TiO2 for electrochemical determination of catechol
No full textThe subject of water contamination and how it gets defiled to the society and humans is confabulating from the past decades. Phenolic compounds widely exist in the water sources and it is emergent to determine the toxicity in natural and drinking water, because it is hazardous to the humans. Among these compounds, catechol has sought a strong concern because of its rapid occurrence in nature and its potential toxicity to humans. The present work aims to develop an effective electrochemical sensing of catechol using mesoporous structure of Fe3O4–TiO2 decorated on glassy carbon (GC) electrode. The creation of pure TiO2 using the sol-gel technique was the first step in the synthesis protocol for binary nanocomposite, which was then followed by the loading of Fe3O4 nanoparticles on the surface of TiO2 using the thermal decomposition method. The resultant Fe3O4–TiO2 based nanocomposite exhibited mesoporous structure and the cavities were occupied with highly active magnetite nanoparticles (Fe3O4) with high specific surface area (90.63 m2/g). When compared to pure TiO2, catechol showed a more prominent electrochemical response for Fe3O4–TiO2, with a significant increase in anodic peak current at a lower oxidation potential (0.387 V) with a detection limit of 45 μM. Therefore, the prepared magnetite binary nanocomposite can serve as an efficient electroactive material for sensing of catechol, which could also act as a promising electrocatalyst for various electrocatalytic applications.Universidad Autónoma de Chil
Historias Naturales, expediciones, redes globales y Museos de Historia Natural en Chile (siglos XVIII-XIX)
No full textNatural History Museums in Chile have been the subject of historical interest because they were closely linked to the formation of the nation-state, and were protagonists of the configuration of a scientific culture in the country. Historical approaches have moved from a historical analysis of 19th century official ideals of «progress», to a new focus on the scientific influences of the 18th century and the importance of the exchanges and global networks of the 19th century, with a particular interest on the people who built those spaces. Therefore, in this paper we consider the temporal span from the enlightened 18th century to the beginning of the 20th century. This period was characterized by a scientific specialization that went beyond the taxonomic classification of nature, to focus on understanding the change and phylogenetic relationship among species as an evolutionary process. In this way, through a historiographical analysis we examine the construction of the history of the collections and the natural history museums, emphasizing in the networks of multiple social actors that contributed to their formation development and public knowledge. © 2023 UNIV CARLOSIII MADRID. All rights reserved.Universidad Autónoma de Chil
A bvrR/bvrS Non-Polar Brucella abortus Mutant Confirms the Role of the Two-Component System BvrR/BvrS in Virulence and Membrane Integrity
No full textBrucella abortus is a bacterial pathogen causing bovine brucellosis worldwide. This facultative extracellular–intracellular pathogen can be transmitted to humans, leading to a zoonotic disease. The disease remains a public health concern, particularly in regions where livestock farming is present. The two-component regulatory system BvrR/BvrS was described by isolating the attenuated transposition mutants bvrR::Tn5 and bvrS::Tn5, whose characterization led to the understanding of the role of the system in bacterial survival. However, a phenotypic comparison with deletion mutants has not been performed because their construction has been unsuccessful in brucellae and difficult in phylogenetically related Rhizobiales with BvrR/BvrS orthologs. Here, we used an unmarked gene excision strategy to generate a B. abortus mutant strain lacking both genes, called B. abortus ∆bvrRS. The deletion was verified through PCR, Southern blot, Western blot, Sanger sequencing, and whole-genome sequencing, confirming a clean mutation without further alterations at the genome level. B. abortus ∆bvrRS shared attenuated phenotypic traits with both transposition mutants, confirming the role of BvrR/BvrS in pathogenesis and membrane integrity. This B. abortus ∆bvrRS with a non-antimicrobial marker is an excellent tool for continuing studies on the role of BvrR/BvrS in the B. abortus lifestyle. © 2023 by the authors.ANID-CHILE; FIDA-UNA, (SIA 0047-17); UCREA-UCR, (15-15-D, 1510171, B8762, C0456, PND-137-15-1); Fondo Nacional de Desarrollo Científico y Tecnológico, FONDECYT, (1210563)Universidad Autónoma de ChileInstituto de Ciencias Biomédica
Development and Evaluation of Cross-Linked Alginate–Chitosan–Abscisic Acid Blend Gel
No full textAbscisic acid (ABA) has been proposed to play a significant role in the ripening of nonclimacteric fruit, stomatal opening, and response to abiotic stresses in plants, which can adversely affect crop growth and productivity. The biological effects of ABA are dependent on its concentration and signal transduction pathways. However, due to its susceptibility to the environment, it is essential to find a suitable biotechnological approach to coat ABA for its application. One promising approach is to utilize alginate and chitosan, two natural polysaccharides known for their strong affinity for water and their ability to act as coating agents. In this study, an alginate–chitosan blend was employed to develop an ABA cover. To achieve this, an alginate–chitosan–abscisic acid (ALG–CS–ABA) blend was prepared by forming ionic bonds or complexes with calcium ions, or through dual cross-linking. This was done by dripping a homogeneous solution of alginate–chitosan and ABA into a calcium chloride solution, resulting in the formation of the blend. By combining the unique properties of alginate, chitosan, and ABA, the resulting ALG–CS–ABA blend can potentially offer enhanced stability, controlled release, and improved protection of ABA. These characteristics make it a promising biotechnological approach for various applications, including the targeted delivery of ABA in agricultural practices or in the development of innovative plant-based products. Further evaluation and characterization of the ALG–CS–ABA blend will provide valuable insights into its potential applications in the fields of biomedicine, agriculture, and tissue engineering. © 2023 by the authors.Vicerrectoría de Investigación y Postgrado de la Universidad Autónoma de Chile; Fondo Nacional de Desarrollo Científico y Tecnológico, FONDECYT, (11220444, 1210107, 1220782, 220014, DIUA 153-2019); Agencia Nacional de Investigación y Desarrollo, ANIDUniversidad Autónoma de Chil
Comparison of Four Treatment Protocols with Intra-Articular Medium Molecular Weight Hyaluronic Acid in Induced Temporomandibular Osteoarthritis: An Experimental Study
No full textThe aim was to compare the effect between a single intra-articular infiltration (1i) and two infiltrations (2i) of medium molecular weight hyaluronic acid (MMW-HA) of high viscosity (HV) and low viscosity (LV) on the histopathological characteristics of temporomandibular joint (TMJ) osteoarthritis (OA) induced in rabbits. An experimental study was conducted on Oryctolagus cuniculus rabbits, including 42 TMJs, distributed between (1) TMJ-C, control group; (2) TMJ-OA, group with OA; (3) TMJ-OA-wt, group with untreated OA; (4) group treated with HA-HV-1i; (5) group treated with HA-HV-2i; (6) group treated with HA-LV-1i; and (7) group treated with HA-LV-2i. The results were evaluated using the Osteoarthritis Research Society International (OARSI) scale and descriptive histology considering the mandibular condyle (MC), the articular disc (AD), and the mandibular fossa (MF). The Kruskal–Wallis test was used for the statistical analysis, considering p < 0.05 significant. All treated groups significantly decreased the severity of OA compared to the TMJ-OA-wt group. The HA-HV-2i group showed significant differences in the degree of OA from the TMJ-OA group. The degree of OA in the HA-HV-2i group was significantly lower than in the HA-LV-1i, HA-LV-2i, and HA-HV-1i groups. The protocol that showed better results in repairing the joint was HA-HV-2i. There are histological differences depending on the protocol of the preparation used: two infiltrations seem to be better than one, and when applying two doses, high viscosity shows better results. © 2023 by the authors.Universidad de La Frontera, UFROUniversidad Autónoma de Chil
Exploring somatosensory innervation of the human lip: A focus on the vermilion
No full textBackground: The lips are a vital component of the face and are densely innervated to perform various functions. The lip edges are covered with mucocutaneous tissue called vermilion which is particularly receptive to touch and temperature. The aim of this study was to investigate the somatosensory innervation of human lips, focusing on sensory corpuscles and the presence of mechano-gated (ASIC2, PIEZO2, and TRPV4) and thermosensing (TRPV1, TRPM2, and RPM8) ion channels within them. Methods: Twelve intact lips (6 upper and 6 lower) were obtained from non-embalmed frozen cadavers (five females and seven males) with an age range of 60–80 years. The specimens were divided into three zones (medial, lateral, and median). The morphotypes of sensory corpuscles and their immunohistochemical profile was analysed. The occurrence of ion channels involved in mechanosensation and temperature detection was examined using various antibodies. Sensory corpuscle density was quantified in vermilion sections, and statistical analyses were conducted to assess differences between the upper and lower lips, as well as between females and males (p < 0.05). Results: Different morphotypes of sensory corpuscles were identified: Ruffini-like associated with hair follicles, Meissner and glomerular corpuscles in the vermilion, and less classifiable sensory corpuscles within the mucosa. The density of sensory corpuscles in the vermilion was higher in the upper lip than in the lower lip; glomerular corpuscles predominated in the medial and median segments, whereas Meissner corpuscles were more abundant in the lateral segment. No sex-related differences were observed in the density or distribution of the two main corpuscular morphotypes. In contrast, the axons of both the glomeruli and Meissner corpuscles regularly displayed ASIC2 and PIEZO2 immunoreactivity, whereas immunoreactivity for TRPV1, TRPV4, TRPM2, and TRPV8 was absent. Conclusions: These results demonstrate that the sensory corpuscles of the vermilion are a mixture of those typical of glabrous skin mucocutaneous tissues. The presence of PIEZO2 and ASIC2 in their axons suggests that these sensory corpuscles function as mechanosensors. © 2023 The AuthorsGobierno del Principado de Asturias, GPA, (PA-21-PF-BP20-122)Universidad Autónoma de Chil