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1.
An Acad Bras Cienc ; 96(2): e20230240, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38747786

RESUMEN

There are few studies related to the biological and ecological aspects of the glass snake, a limbless lizard and with a wide geographic distribution. The aim of this study was to analyze the locomotion mode of specimens of Ophiodes cf. fragilis in different substrates and to investigate the morphological adaptations associated with this type of behavior. We observed that the analyzed specimens presented slide-push locomotion modes and lateral undulation in different substrates, using their hind limbs to aid locomotion in three of the four substrates analyzed. The bones of the hind limbs (proximal - femur - and distal - tibia and fibula) were present and highly reduced and the femur is connected to a thin pelvic girdle. Our data support that hind limbs observed in species of this genus are reduced rather than vestigial. The costocutaneous musculature was macroscopically absent. This is the first study of locomotor behavior and morphology associated with locomotion in Ophiodes, providing important information for studies on morphological evolution in the genus.


Asunto(s)
Adaptación Fisiológica , Lagartos , Locomoción , Animales , Lagartos/anatomía & histología , Lagartos/fisiología , Lagartos/clasificación , Locomoción/fisiología , Adaptación Fisiológica/fisiología , Miembro Posterior/anatomía & histología , Miembro Posterior/fisiología
2.
Artículo en Inglés | MEDLINE | ID: mdl-38869621

RESUMEN

Biosilica (BS) and spongin (SPG) from marine sponges are highlighted for their potential to promote bone regeneration. Moreover, 3D printing is introduced as a technology for producing bone grafts with optimized porous structures, allowing for better cell attachment, proliferation, and differentiation. Thus, this study aimed to characterize the BS and BS/SPG 3D printed scaffolds and to evaluate the biological effects in vitro. The scaffolds were printed using an ink containing 4 wt.% of sodium alginate. The physicochemical characteristics of BS and BS/SPG 3D printed scaffolds were analyzed by SEM, EDS, FTIR, porosity, evaluation of mass loss, and pH measurement. For in vitro analysis, the cellular viability of the MC3T3-E1 cell lineage was assessed using the AlamarBlue® assay and confocal microscopy, while genotoxicity and mineralization potential were evaluated through the micronucleus assay and Alizarin Red S, respectively. SEM analysis revealed spicules in BS, the fibrillar structure of SPG, and material degradation over the immersion period. FTIR indicated peaks corresponding to silicon oxide in BS samples and carbon oxide and amine in SPG samples. BS-SPG scaffolds exhibited higher porosity, while BS scaffolds displayed greater mass loss. pH measurements indicated a significant decrease induced by BS, which was mitigated by SPG over the experimental periods. In vitro studies demonstrated the biocompatibility and non-cytotoxicity of scaffold extracts. .Also, the scaffolds promoted cellular differentiation. The micronucleus test further confirmed the absence of genotoxicity. These findings suggest that 3D printed BS and BS/SPG scaffolds may possess desirable morphological and physicochemical properties, indicating in vitro biocompatibility.

3.
Sensors (Basel) ; 24(6)2024 Mar 09.
Artículo en Inglés | MEDLINE | ID: mdl-38544039

RESUMEN

This study centers on creating a real-time algorithm to estimate brain-to-brain synchronization during social interactions, specifically in collaborative and competitive scenarios. This type of algorithm can provide useful information in the educational context, for instance, during teacher-student or student-student interactions. Positioned within the context of neuroeducation and hyperscanning, this research addresses the need for biomarkers as metrics for feedback, a missing element in current teaching methods. Implementing the bispectrum technique with multiprocessing functions in Python, the algorithm effectively processes electroencephalography signals and estimates brain-to-brain synchronization between pairs of subjects during (competitive and collaborative) activities that imply specific cognitive processes. Noteworthy differences, such as higher bispectrum values in collaborative tasks compared to competitive ones, emerge with reliability, showing a total of 33.75% of significant results validated through a statistical test. While acknowledging progress, this study identifies areas of opportunity, including embedded operations, wider testing, and improved result visualization. Beyond academia, the algorithm's utility extends to classrooms, industries, and any setting involving human interactions. Moreover, the presented algorithm is shared openly, to facilitate implementations by other researchers, and is easily adjustable to other electroencephalography devices. This research not only bridges a technological gap but also contributes insights into the importance of interactions in educational contexts.


Asunto(s)
Encéfalo , Electroencefalografía , Humanos , Reproducibilidad de los Resultados , Electroencefalografía/métodos , Algoritmos , Estudiantes
4.
Sensors (Basel) ; 24(8)2024 Apr 11.
Artículo en Inglés | MEDLINE | ID: mdl-38676053

RESUMEN

Wearable Biosensor Technology (WBT) has emerged as a transformative tool in the educational system over the past decade. This systematic review encompasses a comprehensive analysis of WBT utilization in educational settings over a 10-year span (2012-2022), highlighting the evolution of this field to address challenges in education by integrating technology to solve specific educational challenges, such as enhancing student engagement, monitoring stress and cognitive load, improving learning experiences, and providing real-time feedback for both students and educators. By exploring these aspects, this review sheds light on the potential implications of WBT on the future of learning. A rigorous and systematic search of major academic databases, including Google Scholar and Scopus, was conducted in accordance with the PRISMA guidelines. Relevant studies were selected based on predefined inclusion and exclusion criteria. The articles selected were assessed for methodological quality and bias using established tools. The process of data extraction and synthesis followed a structured framework. Key findings include the shift from theoretical exploration to practical implementation, with EEG being the predominant measurement, aiming to explore mental states, physiological constructs, and teaching effectiveness. Wearable biosensors are significantly impacting the educational field, serving as an important resource for educators and a tool for students. Their application has the potential to transform and optimize academic practices through sensors that capture biometric data, enabling the implementation of metrics and models to understand the development and performance of students and professors in an academic environment, as well as to gain insights into the learning process.


Asunto(s)
Técnicas Biosensibles , Dispositivos Electrónicos Vestibles , Técnicas Biosensibles/instrumentación , Humanos , Electroencefalografía/métodos , Electroencefalografía/instrumentación , Educación , Estudiantes , Aprendizaje
5.
Phys Rev Lett ; 131(13): 131401, 2023 Sep 29.
Artículo en Inglés | MEDLINE | ID: mdl-37832001

RESUMEN

We construct the first four-dimensional multiple black hole solution of general relativity with a positive cosmological constant. The solution consists of two static black holes whose gravitational attraction is balanced by the cosmic expansion. These static binaries provide the first four-dimensional example of nonuniqueness in general relativity without matter.

6.
Phys Rev Lett ; 131(9): 091402, 2023 Sep 01.
Artículo en Inglés | MEDLINE | ID: mdl-37721835

RESUMEN

We show that extremal Kerr black holes are sensitive probes of new physics. Stringy or quantum corrections to general relativity are expected to generate higher-curvature terms in the gravitational action. We show that in the presence of these terms, asymptotically flat extremal rotating black holes have curvature singularities on their horizon. Furthermore, near-extremal black holes can have large yet finite tidal forces for infalling observers. In addition, we consider five-dimensional extremal charged black holes and show that higher-curvature terms can have a large effect on the horizon geometry.

7.
BMC Pediatr ; 23(1): 232, 2023 05 11.
Artículo en Inglés | MEDLINE | ID: mdl-37170193

RESUMEN

BACKGROUND: The importance of physical activity in the first months of age is well known, however, with the evolution of the urban environment, the excessive workload of parents and the excessive time in growing up in kindergartens has limited this same free practice and little has been studied about this issue. In Portugal, there are institutions that provide oriented physical activity for their children, however, this is optional, which may create disadvantages in children's motor skills in these ages. OBJECTIVE: The objective of the study isto verify if there are differences in the development of motor skills (global and fine) comparing children between 12 and 48 months who practice oriented physical activity (OPA) and children who do not. METHODS: Participated in this study, 400 children of both genders (28.14 ± 7.23 months). Two groups were created (the group that had oriented physical activity (30 min long and 2 times a week) and the group that didn't have oriented physical activity). For a better understanding they were divided into 3 age groups (12-23, 24-35 and 36-48 months). Motor skills were assessed using the PDMS-2 scales, for 6 months, following the instrument's application standards. RESULTS: In a first analysis, we found that the majority of children only start to practice oriented physical activity in institutions from 36 months of age, however, it is in the first months (from 12 to 35) that the greatest differences between the two groups can occur. The OPA group presented better results according to the mean values, in all motor skills. Differences between groups were most noticeable in Postural, locomotion and fine manipulation Skills (showing effect size: moderate and low). CONCLUSIONS: We can conclude that a practice of oriented physical activity in the first 48 months is fundamental to the development of motor skills. It is in the first months (up to 36) that there are greater differences, but it is also where there are less children carrying out guided physical activity. This is an important factor, and is determinant to make institutions aware of this importance of this variable in child development.


Asunto(s)
Desarrollo Infantil , Destreza Motora , Niño , Humanos , Masculino , Femenino , Lactante , Ejercicio Físico , Padres , Portugal
8.
Reprod Domest Anim ; 58(7): 946-954, 2023 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-37133263

RESUMEN

Most embryo losses occur in the first trimester of pregnancy in cows and include losses following embryo transfer. There is a resulting negative economic impact on cattle production systems when this occurs. Cellular and molecular mechanisms behind the maternal immune response to the growing embryo have not been fully characterized. The objective of this study was to examine the gene expression profiles of peripheral white blood cells (PWBCs) from pregnant cows 21 days after an embryo was transferred, and cows that were treated equally but lost the embryo. Specifically, we obtained and compared the transcriptome of PWBC from heifers that became pregnant at day 21 (N = 5) or failed to become pregnant after the embryo transfer (N = 5). Sequencing data can be accessed by Gene Expression Omnibus (GEO) with the accession number GSE210665. A total of 13,167 genes were evaluated for differential expression between groups. A total of 682 genes showed differential expression (p-value <.01), 302 genes were up-regulated while 380 were down-regulated due to pregnancy. The most significant genes were COL1A2, H2AC18, HTRA1, MMP14, CD5L, ADAMDEC1, MYO1A and RPL39, among others. Most of the significant genes are related to the up-regulation of inflammatory chemokine activity and immune defence response. Our findings extend the current knowledge that pregnancy alters the PWBC by promoting immune tolerance, cell chemotaxis, blood coagulation, angiogenesis, inflammatory response, cell adhesion and cytokine secretion. Our data suggest that pregnancy and ectoparasites could trigger poorly described genes in PWBC of cows, and a few previously escribed genes, such as IFI44. These results could shed light on the genes and mechanisms that promote tolerance to pregnancy and allow survival of the developing embryo.


Asunto(s)
Transferencia de Embrión , Transcriptoma , Embarazo , Bovinos/genética , Animales , Femenino , Transferencia de Embrión/veterinaria , Transferencia de Embrión/métodos , Leucocitos , Tolerancia Inmunológica/genética
9.
Bioprocess Biosyst Eng ; 46(7): 1053-1063, 2023 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-37199771

RESUMEN

Collagen dressings have been widely used as effective treatments for chronic wounds acting as barrier, protecting the area from infections and participating in the healing process. Collagen from fish skin is biocompatible, presents low immunogenicity and is able of stimulating wound healing. In this scenario, skin of flounder fish (Paralichthys sp.) may constitute a promising source for collagen. Then, our hypothesis is that fish collagen is able of increasing cell proliferation, with no cytotoxicity. In this context, the aim of the present study was to investigate the physicochemical and morphological properties of collagen using scanning electron microscopy (SEM), Energy dispersive X-ray spectroscopy (EDS), mass loss and pH. Moreover, the cytotoxicity and genotoxicity of collagen were studied using in vitro studies (cell viability, comet assay and micronucleus assay). Fish collagen showed no variation of pH and mass weight, with characteristic peaks of collagen in FTIR. Furthermore, all the extracts presented cell viability at least over 50% and no cytotoxicity was observed. Regarding genotoxicity data, the results showed that only the extract of 100% showed higher values in comparison with negative control group for CHO-K1 cell line as depicted by comet and micronucleus assays. Based on the results, it is suggested that fish collagen is biocompatible and present non-cytotoxicity in the in vitro studies, being considered a suitable material for tissue engineering proposals.


Asunto(s)
Lenguado , Cricetinae , Animales , Colágeno/farmacología , Cicatrización de Heridas , Piel/química , Peces , Células CHO
10.
Sensors (Basel) ; 23(8)2023 Apr 12.
Artículo en Inglés | MEDLINE | ID: mdl-37112274

RESUMEN

Providing energy from fusion and finding ways to scale up the fusion process to commercial proportions in an efficient, economical, and environmentally benign way is one of the grand challenges for engineering. Controlling the burning plasma in real-time is one of the critical issues that need to be addressed. Plasma Position Reflectometry (PPR) is expected to have an important role in next-generation fusion machines, such as DEMO, as a diagnostic to monitor the position and shape of the plasma continuously, complementing magnetic diagnostics. The reflectometry diagnostic uses radar science methods in the microwave and millimetre wave frequency ranges and is envisaged to measure the radial edge density profile at several poloidal angles providing data for the feedback control of the plasma position and shape. While significant steps have already been given to accomplish that goal, with proof of concept tested first in ASDEX-Upgrade and afterward in COMPASS, important, ground-breaking work is still ongoing. The Divertor Test Tokamak (DTT) facility presents itself as the appropriate future fusion device to implement, develop, and test a PPR system, thus contributing to building a knowledge database in plasma position reflectometry required for its application in DEMO. At DEMO, the PPR diagnostic's in-vessel antennas and waveguides, as well as the magnetic diagnostics, may be exposed to neutron irradiation fluences 5 to 50 times greater than those experienced by ITER. In the event of failure of either the magnetic or microwave diagnostics, the equilibrium control of the DEMO plasma may be jeopardized. It is, therefore, imperative to ensure that these systems are designed in such a way that they can be replaced if necessary. To perform reflectometry measurements at the 16 envisaged poloidal locations in DEMO, plasma-facing antennas and waveguides are needed to route the microwaves between the plasma through the DEMO upper ports (UPs) to the diagnostic hall. The main integration approach for this diagnostic is to incorporate these groups of antennas and waveguides into a diagnostics slim cassette (DSC), which is a dedicated complete poloidal segment specifically designed to be integrated with the water-cooled lithium lead (WCLL) breeding blanket system. This contribution presents the multiple engineering and physics challenges addressed while designing reflectometry diagnostics using radio science techniques. Namely, short-range dedicated radars for plasma position and shape control in future fusion experiments, the advances enabled by the designs for ITER and DEMO, and the future perspectives. One key development is in electronics, aiming at an advanced compact coherent fast frequency sweeping RF back-end [23-100 GHz in few µs] that is being developed at IPFN-IST using commercial Monolithic Microwave Integrated Circuits (MMIC). The compactness of this back-end design is crucial for the successful integration of many measurement channels in the reduced space available in future fusion machines. Prototype tests of these devices are foreseen to be performed in current nuclear fusion machines.

11.
Sensors (Basel) ; 23(2)2023 Jan 10.
Artículo en Inglés | MEDLINE | ID: mdl-36679607

RESUMEN

This paper presents an integrated monitoring system for the driver and the vehicle in a single case of study easy to configure and replicate. On-board vehicle sensors and remote sensors are combined to model algorithms for estimating polluting emissions, fuel consumption, driving style and driver's health. The main contribution of this paper is the analysis of interactions among the above monitored features highlighting the influence of the driver in the vehicle performance and vice versa. This analysis was carried out experimentally using one vehicle with different drivers and routes and implemented on a mobile application. Compared to commercial driver and vehicle monitoring systems, this approach is not customized, uses classical sensor measurements, and is based on simple algorithms that have been already proven but not in an interactive environment with other algorithms. In the procedure design of this global vehicle and driver monitoring system, a principal component analysis was carried out to reduce the variables used in the training/testing algorithms with objective to decrease the transfer data via Bluetooth between the used devices: a biometric wristband, a smartphone and the vehicle's central computer. Experimental results show that the proposed vehicle and driver monitoring system predicts correctly the fuel consumption index in 84%, the polluting emissions 89%, and the driving style 89%. Indeed, interesting correlation results between the driver's heart condition and vehicular traffic have been found in this analysis.


Asunto(s)
Conducción de Automóvil , Aplicaciones Móviles , Accidentes de Tránsito , Computadores , Teléfono Inteligente
12.
J Fish Biol ; 103(5): 950-964, 2023 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-37339932

RESUMEN

Research on life-history variations in widely distributed fish species is needed to understand global warming impacts on populations and to improve fisheries management advice. The lane snapper Lutjanus synagris (Linnaeus, 1758) is commercially important to fisheries in the Western Central Atlantic, where spread information on its life-history traits is available. We studied growth, age, reproduction and mortality of lane snapper in the Guatemalan Caribbean, the warmest part of its distribution range, and collated the new information with published data in a latitudinal analysis extending between 18°S and 30°N. Longevity was estimated at 11 years, and von Bertalanffy growth parameters were asymptotic length (Linf) 45.6 and 42.2 cm for females and males, respectively, the growth coefficient (K) was 0.1 year-1 and the theoretical age at zero length (t0 ) was -4.4 years. Lane snapper grew slowest in April, prior to the rainy season, and at the onset of the reproductive season, which lasted from May to October. Fifty percent of female and male lane snappers matured at 23 and 17 cm, corresponding to 3.5 and 2.4 years of age respectively. A regional multivariate analysis found seawater temperature to be an important driver of life-history variation. Lane snapper lifespan was shorter at the warm edge of its distribution range, and maximum size and peak reproductive investment were negatively related to sea surface temperature. The trade-offs in lane snapper life-history traits and phenology likely enhance its fitness to differing environments. Interpolation from the present regional estimates to less-studied regions of the Caribbean is useful for preliminary understanding of reaction norms and harvest potentials.


Asunto(s)
Rasgos de la Historia de Vida , Perciformes , Animales , Masculino , Femenino , Peces , Explotaciones Pesqueras , Reproducción
13.
Acta Chir Belg ; 123(5): 544-549, 2023 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-35253620

RESUMEN

BACKGROUND: Bronchobiliary fistula is a rare and complex entity defined by an abnormal communication between the biliary and bronchial systems. The etiopathogenesis is not completely understood, but the most common factors implicated are hepatobiliary tumors, biliary obstruction, iatrogenic damage or trauma. METHODS: Here we present a case of a 69-year-old man that developed a bronchobiliary fistula and a pulmonary abscess after migration of a bile duct stent placed as part of the treatment of an iatrogenic bile duct injury that occurred during elective cholecystectomy. RESULTS: A conservative approach, that included broad-spectrum antibiotic, removal of the stent, and sphincterotomy, was enough for the closure of the fistula and resolution of the symptoms. CONCLUSION: We emphasize the importance of prompt recognition of this entity and a concerted therapeutic strategy to optimize the probability of success, avoiding the destructive consequences of the bile in the pulmonary parenchyma and septic complications.


Asunto(s)
Fístula Biliar , Fístula Bronquial , Masculino , Humanos , Anciano , Colangiopancreatografia Retrógrada Endoscópica/efectos adversos , Fístula Biliar/diagnóstico , Fístula Biliar/etiología , Fístula Biliar/cirugía , Conductos Biliares , Colecistectomía/efectos adversos , Fístula Bronquial/diagnóstico por imagen , Fístula Bronquial/etiología , Fístula Bronquial/cirugía , Stents/efectos adversos , Enfermedad Iatrogénica
14.
Gac Med Mex ; 159(1): 44-48, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-36930557

RESUMEN

INTRODUCTION: Owing to its ability to reduce the toxicity of environmental pollutants that are risk factors for diabetes and obesity, the use of probiotic bacteria might aid the treatment of these diseases. OBJECTIVE: To determine the effects of chronic exposure to low-dose malathion on weight and glucose levels in mice, as well as to evaluate the protective role of a probiotic supplement. METHODS: Weight and serum glucose levels of four groups of mice (control, malathion-exposed [10 ppm], probiotics and malathion + probiotics) were determined every 10 days for 180 days. RESULTS: Malathion administration induced an increase in weight and glucose levels in the malathion group mice in comparison with the other groups. CONCLUSIONS: Consumption of food contaminated with malathion residues increases glucose levels and favors weight gain, while consumption of probiotics reduces the effects generated by residues in food.


INTRODUCCIÓN: Debido a su capacidad para reducir la toxicidad de contaminantes ambientales que constituyen factores de riesgo de diabetes y obesidad, el uso de bacterias probióticas podría ayudar al tratamiento de esas enfermedades. OBJETIVO: Determinar los efectos de la exposición crónica a malatión a dosis bajas sobre el peso y los niveles de glucosa de ratones, así como evaluar el papel protector de un suplemento probiótico. MÉTODOS: Cada 10 días se determinó el peso y la glucosa sérica de cuatro grupos de ratones (de control, expuestos a malatión (10 ppm), probióticos y malatión + probióticos) durante 180 días. RESULTADOS: La administración de malatión provocó un incremento del peso y los niveles de glucosa en los ratones del grupo con malatión comparados con los demás grupos. CONCLUSIONES: El consumo de alimentos contaminados con residuos de malatión aumenta los niveles de glucosa y favorece el incremento del peso; el consumo de probióticos disminuye los efectos generados por los residuos en los alimentos.


Asunto(s)
Malatión , Probióticos , Ratones , Animales , Malatión/toxicidad , Aumento de Peso , Obesidad/prevención & control , Probióticos/uso terapéutico , Glucosa
15.
Cell Tissue Res ; 388(3): 489-502, 2022 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-35451648

RESUMEN

Collagen extracted from fishes has been appearing as an alternative for commercial porcine and bovine collagen and it has been considered interesting especially for membrane manufacturing in tissue engineering. Despite the positive in vitro effects of fish collagen membranes, there is still no understanding of all the benefits that this natural biomaterial plays in the wound healing process, due to the lack of compilation of the results obtained in animal studies. In this sense, the purpose of this study was to perform a systematic review of the literature to examine the effects of fish collagen membranes for skin wound healing in experimental models of skin wound. The search was carried out according to the orientations of Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA), and the descriptors of the Medical Subject Headings (MeSH) were defined: "fish," collagen," "skin," and "in vivo". A total of 10 articles were retrieved from the databases PubMed and Scopus. After the elegibility analyses, this review covers the different origins of fish collagen reported in the different papers from the beginning of 2015 through the middle of 2021. The results were based mainly on histological analysis and macroscopic evaluation, and fish skin collagen was responsible for improving the wound healing rate and the process of reepithelization and collagen deposition. In conclusion, fish skin collagen has shown positive results in in vivo studies and may be a potential biomaterial in tissue engineering.


Asunto(s)
Colágeno , Cicatrización de Heridas , Animales , Materiales Biocompatibles/farmacología , Bovinos , Colágeno/farmacología , Peces , Piel , Porcinos
16.
Phys Rev Lett ; 128(2): 021601, 2022 Jan 14.
Artículo en Inglés | MEDLINE | ID: mdl-35089733

RESUMEN

We find rotating black hole solutions in the Randall-Sundrum II (RSII) model, by numerically solving a three-dimensional PDE problem using pseudospectral collocation methods. We compute the area and equatorial innermost stable orbits of these solutions. For large black holes compared with the AdS length scale ℓ the black hole exhibits four-dimensional behavior, approaching the Kerr metric on the brane, while for small black holes, the solution tends instead towards a five-dimensional Myers-Perry black hole with a single nonzero rotation parameter aligned with the brane. This departure from exact four-dimensional gravity may lead to different phenomenological predictions for rotating black holes in the RSII model to those in standard four-dimensional general relativity. This Letter provides a stepping stone for studying such modifications.

17.
Philos Trans A Math Phys Eng Sci ; 380(2228): 20210010, 2022 Jul 25.
Artículo en Inglés | MEDLINE | ID: mdl-35658680

RESUMEN

In this research, a vagus nerve stimulator has been developed and miniaturized for use in epilepsy research. The board contains all the components necessary for its operation during the standard duration of the experiments, being possible to control it once implanted and even being able to reuse it. The VNS system has been designed for rodents since the VNS devices available for human are not only too large for laboratory animals, but also too expensive. With this solution the expenditure on materials made by laboratories is greatly reduced and bioethical considerations were kept in mind. The system was validated in hamsters. This article is part of the theme issue 'Advanced neurotechnologies: translating innovation for health and well-being'.


Asunto(s)
Experimentación Animal , Epilepsia , Estimulación del Nervio Vago , Animales , Epilepsia/terapia , Resultado del Tratamiento , Nervio Vago/fisiología
18.
Environ Res ; 210: 112952, 2022 07.
Artículo en Inglés | MEDLINE | ID: mdl-35182601

RESUMEN

Microplastics have been studied in sediments from coastal and aquatic environments, but contamination of mangrove soils is still relatively unknown in most mangroves around the world. In this study, the presence of microplastics was investigated in six mangrove soils around the Todos Santos Bay (TSB), the largest and most important navigable bay on the Brazilian coast. Samples were collected at three depths (surface, 10 cm, and 30 cm) at three different distances from the lower tidal area. Ten grams of soil were sieved in a 150 µm mesh and centrifuged with ZnCl2 solution (density of 1.5 kg dm-3) for the extraction of microplastics. The microplastics were quantified, measured, and described using a systematic photographic method and the ImageJ program. Microplastics were abundant in all samples, with a mean of 10,782 ± 7,671 items kg-1 (max.: 31,087 items kg-1, only one sample <2,000 items kg-1), higher than any other value reported worldwide. The abundances varied among the six mangroves studied, with a predominance of fibers and mean size of 196 µm. Even remote mangroves were highly polluted, reflecting a large dispersion of the pollutants. The abundance did not differ significantly between soil depths, evidencing a continuous input and burial of microplastics in the soil up to 30 cm. The investigation of the source of microplastics and their presence in water and biota is urgent in this Brazilian region, and these results emphasize the need for global actions to protect coastal ecosystems.


Asunto(s)
Microplásticos , Contaminantes Químicos del Agua , Bahías , Brasil , China , Ecosistema , Monitoreo del Ambiente , Sedimentos Geológicos , Plásticos , Suelo , Contaminantes Químicos del Agua/análisis
19.
Sensors (Basel) ; 22(6)2022 Mar 09.
Artículo en Inglés | MEDLINE | ID: mdl-35336275

RESUMEN

Recent theoretical studies demonstrate the advantages of using decentralized architectures over traditional centralized architectures for real-time Power Distribution Systems (PDSs) operation. These advantages include the reduction of the amount of data to be transmitted and processed when performing state estimation in PDSs. The main contribution of this paper is to provide lab validation of the advantages and feasibility of decentralized monitoring of PDSs. Therefore, this paper presents an advanced trial emulating realistic conditions and hardware setup. More specifically, the paper proposes: (i) The laboratory development and implementation of an Advanced Measurement Infrastructure (AMI) prototype to enable the simulation of a smart grid. To emulate the information traffic between smart meters and distribution operation centers, communication modules, that enable the use of wireless networks for sending messages in real-time, are used, bridging concepts from both IoT and Edge Computing. (ii) The laboratory development and implementation of a decentralized architecture based on Embedded State Estimator Modules (ESEMs) are carried out. ESEMs manage information from smart meters at lower voltage networks, performing real-time state estimation in PDSs. Simulations performed on a real PDS with 208 buses (considering both medium and low voltage buses) have met the aims of this paper. The results show that by using ESEMs in a decentralized architecture, both the data transit through the communication network, as well as the computational requirements involved in monitoring PDSs in real-time, are reduced considerably without any loss of accuracy.


Asunto(s)
Sistemas de Computación , Simulación por Computador , Medios de Cultivo
20.
Sensors (Basel) ; 22(5)2022 Feb 28.
Artículo en Inglés | MEDLINE | ID: mdl-35271028

RESUMEN

The present work describes the implementation of a prototype to characterize thermoelectric modules (TEM). The goal is to study the energy conversion by means of thermoelectric modules mounted on concrete structures. The proposed experimental system is used for the electrical characterization of a commercially available thermoelectric module TEC1-12710 to prove its operation while embedded in a concrete slab, typical of building constructions. In this case, the parameters that define thermal energy conversion into electrical energy are open-circuit voltage generation, loaded circuit voltage generation, and load current. A known external load is connected to the terminals of the TEM for the purpose of its electric characterization. An electrical heating element on the hot side and a thermoelectric cooler on the cold side produce a temperature difference on the concrete slab. This arrangement allows the emulation of a temperature gradient produced by sunlight over a concrete structure. The objective is to measure the resulting electrical energy produced by the combination of concrete slab and the thermoelectric module. By controlling the temperature difference between the sides of the thermoelectric module under test, it is possible to simulate the effect of the temperature gradient under different sunlight conditions. Two digital PI controllers regulate the temperature conditions, thus providing controlled conditions for the experiments.

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