Publications by authors named "Oyarzun P"

Intersexuality is a reproductive phenomenon that occurs in some gonochoric species and refers to the simultaneous presence of both male and female gametes within the same individual. Although this phenomenon has been reported in various invertebrate species, many aspects remain poorly understood, especially in marine mussels. However, it has been suggested that the prevalence of parasites within populations could induce the occurrence of intersex animals.

View Article and Find Full Text PDF

Bacterial nanocellulose (BNC) is a biopolymer that is drawing significant attention for a wide range of applications thanks to its unique structure and excellent properties, such as high purity, mechanical strength, high water holding capacity and biocompatibility. Nevertheless, the biomanufacturing of BNC is hindered due to its low yield, the instability of microbial strains and cost limitations that prevent it from being mass-produced on a large scale. Various approaches have been developed to address these problems by genetically modifying strains and to produce BNC-based biomaterials with added value.

View Article and Find Full Text PDF

Bacterial nanocellulose (BNC) is a sustainable, renewable, and eco-friendly nanomaterial, which has gained great attentions in both academic and industrial fields. Two bacterial nanocellulose-producing strains (CVV and CVN) were isolated from apple vinegar sources, presenting high 16S rRNA gene sequence similarities (96%-98%) with species. The biofilm was characterized by scanning electron microscopy (SEM), revealing the presence of rod-shaped bacteria intricately embedded in the polymeric matrix composed of nanofibers of bacterial nanocellulose.

View Article and Find Full Text PDF

Background: Disseminated neoplasia (DN) is a proliferative cell disorder of the circulatory system of bivalve mollusks. The disease is transmitted between individuals and can also be induced by external chemical agents such as bromodeoxyuridine. In Mya arenaria, we have cloned and characterized an LTR-retrotransposon named Steamer.

View Article and Find Full Text PDF

The genetic characteristics of invasive species have a significant impact on their ability to establish and spread. The blue mussel (), native to the Mediterranean Sea, is a leading invasive species of intertidal coasts throughout much of the world. Here, we used mitochondrial DNA sequence data to investigate the genetic diversity and phylogeographic structure of invasive () versus native () populations of blue mussels in Chile.

View Article and Find Full Text PDF

In recent years, advances in analyses of the sperm morphology and genetics of have allowed to two evolutionary scenarios for this mussel to be suggested: (1) the scenario of cryptic species and (2) the scenario of incipient or in progress speciation. For a better understanding of the evolutionary history of , we performed extensive sampling along a latitudinal gradient of ca. 7180 km of coastline-from the Southern Pacific Ocean to the Atlantic Ocean-and we delved deeper into the sperm morphology of , exploring its association with the phylogeny and population genetics to determine whether the variability in sperm traits between the northern and southern regions was a signal of cryptic or incipient species.

View Article and Find Full Text PDF

Gold nanoparticles (AuNPs) exhibit unique properties that make them appealing for applications in biosensing and other emerging fields. Despite the availability of numerous synthesis methods, important questions remain to be addressed regarding the volume effect on the synthesis yield and quality of AuNPs in the light of biosensing research. The present study addresses these issues by developing a novel microvolumetric citrate-reduction method to improve the synthesis of AuNPs, which were characterized by electronic microscopy, energy dispersive spectroscopy, zeta potential and colorimetric analysis.

View Article and Find Full Text PDF

A high throughput method was developed to detect bioactive molecules with inhibitory activity over cyclooxygenase (COX-2) enzyme applying effect-directed analysis and planar chromatography hyphenated with bioassay and mass spectrometry. The assay was based on the indirect measurement of arachidonic acid transformation into prostaglandin with the colorimetric co-substrate N,N,N',N'-tetramethyl-p-phenylenediamine. Inhibitory zones were observed as colorless bands over a blue background.

View Article and Find Full Text PDF
Article Synopsis
  • The blue mussel is a vital species for the economy of southern Chile, especially in aquaculture, where its growth and survival are challenged by environmental factors and pathogens.
  • A high-quality reference genome was created, marking the first chromosome-level genome for a Mytilidae species in South America, with a genome size of 1.93 Gb and 34,530 genes identified.
  • The study underscores the importance of understanding genetic adaptations and variations among mussel populations to enhance sustainable production practices in aquaculture.
View Article and Find Full Text PDF
Article Synopsis
  • Aflatoxin contamination in cattle feed poses significant risks to both animal and human health.
  • Various aptasensor methods have been explored for detecting aflatoxin B1 (AFB1) in feed, but quick analysis has remained a challenge due to complicated sample preparation.
  • This study presents an improved method using a gold nanoparticle-based aptasensor for semi-quantitative colorimetric detection of AFB1, utilizing acetonitrile as an effective solvent, enabling direct detection from crude feed extracts with a detection limit of 5 µg/kg.
View Article and Find Full Text PDF

Purpose: Different measuring instruments have been described to determine the prevalence of voice disorders in schoolteachers. However, the heterogeneity of prevalence figures has made it difficult in determining the impact of voice disorders in this group. This investigation aims to review and identify scientific evidence of methodological analysis of voice disorders in teachers, the relevance of measuring instruments, the prevalence of dysphonia, and the impact on the development of vocal health prevention programs.

View Article and Find Full Text PDF

Oysters and blue mussels are important hydrobiological resources for aquaculture. In Chile, they are farming on the Chiloé island, where around 18% of the world's mussels are produced, however, their nutritional dynamics are largely unknown. For this reason, the objective of this study was to determine the proximal biochemical composition and the fatty acid profile in the Chilean oyster (Ostrea chilensis), the Pacific oyster (Crassostrea gigas) and the Chilean mussel (Mytilus chilensis), to perform an intra and interspecific comparison.

View Article and Find Full Text PDF

Juvenile oysters (Ostrea chilensis) from two populations (Quempillén estuary and Pullinque bay) were exposed to a toxic diet containing paralytic shellfish toxins (PST), produced by Alexandrium catenella, followed by a detoxification period. Feeding behaviour, toxin profile, dynamics of intoxication/detoxification, and survival were evaluated over the entire experimental period. Both populations reduced their feeding rates during the 30-day exposure to the toxic diet.

View Article and Find Full Text PDF

Background: The Atacama salt flat is located in northern Chile, at 2300 m above sea level, and has a high concentration of lithium, being one of the main extraction sites in the world. The effect of lithium on microorganism communities inhabiting environments with high concentrations of this metal has been scarcely studied. A few works have studied the microorganisms present in lithium-rich salt flats (Uyuni and Hombre Muerto in Bolivia and Argentina, respectively).

View Article and Find Full Text PDF

Ostrea chilensis (Küster, 1844), the flat oyster, is native to Chile and New Zealand. In Chile, it occurs in a few natural beds, from the northern part of Chiloé Island (41 ºS) to the Guaitecas Archipelago (45 ºS). This bivalve is slow growing, broods its young, and has very limited dispersal potential.

View Article and Find Full Text PDF

The misuse of antibiotics in the cattle sector can lead to milk contamination, with concomitant effects on the dairy industry and human health. Biosensors can be applied in this field; however, the influence of the milk matrix on their activity has been poorly studied in light of the preanalytical process. Herein, aptamer-conjugated gold nanoparticles (nanoaptasensors) were investigated for the colorimetric detection in raw milk of four antibiotics used in cattle.

View Article and Find Full Text PDF

Topical drug delivery is a promising approach to treat different skin disorders. However, it remains a challenge mainly due to the nature and rigidity of the nanosystems, which limit deep skin penetration, and the unsuccessful demonstration of clinical benefits; greater penetration by itself, does not ensure pharmacological success. In this context, transfersomes have appeared as promising nanosystems; deformability, their unique characteristic, allows them to pass through the epidermal microenvironment, improving the skin drug delivery.

View Article and Find Full Text PDF

Background: A decrease in rainfall is one of the main constraints on wheat production, although the association of wheat with arbuscular mycorrhizal fungi (AMF) may be an alternative for crop production under drought conditions. In the present study, we used three wheat cultivars (Purple, Ilustre and Maxi Baer) inoculated with two AMF strains, one obtained from the hyperarid Atacama Desert (northern Chile; Fm) and the other obtained from southern Chile (Cc). Plants were maintained under two irrigation conditions (normal irrigation and drought) and the physiological behaviour and enzymatic and nonenzymatic antioxidant activities in the shoots were determined.

View Article and Find Full Text PDF

Smooth-shelled blue mussels, Mytilus spp., have a worldwide antitropical distribution and are ecologically and economically important. Mussels of the Mytilus edulis species complex have been the focus of numerous taxonomic and biogeographical studies, in particular in the Northern hemisphere, but the taxonomic classification of mussels from South America remains unclear.

View Article and Find Full Text PDF
Article Synopsis
  • Emerging infectious diseases (EIDs), particularly those caused by viruses like SARS-CoV-2, are on the rise, highlighting the urgent need for better vaccine strategies that consider genetic diversity.
  • The genetic variations in human leukocyte antigen (HLA) molecules impact how different ethnic groups respond to vaccines, complicating vaccine candidate selection.
  • Predivac-3.0 is an innovative immunoinformatics tool designed to discover T-cell epitopes while factoring in these ethnic differences, demonstrating strong predictive accuracy compared to existing methods and showcasing its application in identifying potential immune responses against COVID-19 based on the HLA profiles of populations.
View Article and Find Full Text PDF

An environmentally friendly nanocomposite adsorbent composed of two renewable biomaterials, bacterial cellulose (BC) nanofibrils and hydroxyapatite (HA) nanocrystals, was synthetized by an in situ wet chemical precipitation technique, using clam shell biowaste as feedstock. HA nanocrystals embedded in an ultrafine BC network were confirmed and characterized trough different instrumental techniques (SEM, FTIR, XRD, EDS, surface charge and BET analysis), describing its nanostructure, chemical composition and thermal stability. The adsorptive removal of lead ions by the nanocomposite was investigated through batch experiments conducted under different pH, contact times and Pb(II) initial concentrations, proving that the process was highly favorable according to the Langmuir isotherm model (monolayer adsorption) with chemisorption as the main mechanism and kinetic data obeying a nonlinear pseudo-second order kinetic model.

View Article and Find Full Text PDF

In this article we present the development of a biosensor system that integrates nanotechnology, optomechanics and a spectral detection algorithm for sensitive quantification of antibiotic residues in raw milk of cow. Firstly, nanobiosensors were designed and synthesized by chemically bonding gold nanoparticles (AuNPs) with aptamer bioreceptors highly selective for four widely used antibiotics in the field of veterinary medicine, namely, Kanamycin, Ampicillin, Oxytetracycline and Sulfadimethoxine. When molecules of the antibiotics are present in the milk sample, the interaction with the aptamers induces random AuNP aggregation.

View Article and Find Full Text PDF

Chaura (Gaultheria poeppigii) is a plant species native from Southern Chile, which produces a berry fruit with potential beneficial health effects due to its content of phenolic compounds. The qualitative and quantitative determination of the phenolic compounds from fruits of different colored genotypes (white-, pink- and red-colored) collected from the Osorno volcano and the Conguillío National Park (CNP) in southern Chile were analyzed by mass spectrometry (HPLC-DAD-ESI-MS/MS) and HPLC-DAD, respectively. The total content of phenolic compounds was evaluated by the Folin-Ciocalteu method, and its antioxidant activity by the CUPRAC, TEAC and DPPH methods.

View Article and Find Full Text PDF

is a ubiquitous necrotrophic filamentous fungal phytopathogen that lacks host specificity and can affect more than 1000 different plant species. In this work, we explored [(E)-2-{[(2-aminopyridin-2-yl)imino]-methyl}-4,6-di-tert-butylphenol], a pyridine Schiff base harboring an intramolecular bond (IHB), regarding their antifungal activity against Botrytis cinerea. Moreover, we present a full characterization of the L1 by NMR and powder diffraction, as well as UV-vis, in the presence of previously untested different organic solvents.

View Article and Find Full Text PDF

The coordination of the ligands with respect to the central atom in the complex bromido-tricarbon-yl[diphen-yl(pyridin-2-yl)phosphane-κ ,]rhenium(I) chloro-form disolvate, [ReBr(CHNP)(CO)]·2CHCl or [κ-,-{(CH)(CHN)P}Re(CO)Br]·2CHCl, (·2CHCl), is best described as a distorted octa-hedron with three carbonyls in a facial conformation, a bromide atom, and a biting ,-di-phenyl-pyridyl-phosphine ligand. Hirshfeld surface analysis shows that C-Cl⋯H inter-actions contribute 26%, the distance of these inter-actions are between 2.895 and 3.

View Article and Find Full Text PDF