1. Investigación

Background: Patient safety is essential in small animal anaesthesia. Thisstudy aimed to assess anaesthesia-related deaths in cats worldwide, identifyrisk and protective factors and provide insights for clinical practice.Methods: A prospective multicentre cohort study of 14,962 cats from198 veterinary centres across different countries was conducted. Data onanaesthesia-related deaths, from premedication up to 48 hours postex-tubation, were collected. Logistic regression was used to analyse patientdemographics, American Society of Anesthesiologists (ASA) classification,procedure type and anaesthetic drugs.Results: The anaesthesia-related mortality was 0.63%, with 74.5% of deathsoccurring postoperatively. Cats with cachexia, a higher ASA status or whounderwent abdominal, orthopaedic/neurosurgical or thoracic proceduresexhibited elevated mortality. Mechanical ventilation use was associated withincreased mortality. Mortality odds were reduced by the use of alpha2 -agonistsedatives, pure opioids in premedication and locoregional techniques.Limitations: Limitations include non-randomised sampling, potentialbiases, unquantified response rates, subjective death cause classification andlimited variable analysis.Conclusions: Anaesthetic mortality in cats is significant, predominantlypostoperative. Risk factors include cachexia, higher ASA status, specificprocedures and mechanical ventilation. Protective factors include alpha2 -agonist sedatives, pure opioids and locoregional techniques. These findingscan help improve anaesthesia safety and outcomes. However, further researchis required to improve protocols, enhance data quality and minimise risks.

Background:Ensuring patient safety during small animal anaesthesia is cru-cial. This study aimed to assess anaesthetic-related deaths in dogs globally,identify risks and protective factors and inform clinical practice.Methods:This prospective cohort multicentric study involved 55,022 dogsfrom 405 veterinary centres across various countries. Data on anaesthesia-related deaths from premedication to 48 hours post-extubation werecollected. Logistic regression was used to analyse patient demographics,American Society of Anesthesiologists (ASA) classification, procedure typeand anaesthetic drugs used.Results:Anaesthetic-related mortality was 0.69%. Most deaths occurred post-operatively (81%). Age, obesity and a higher ASA classification score wereassociated with increased mortality. Urgent procedures, non-urgent butunscheduled anaesthesias and short procedures also had higher mortality.Some sedatives, systemic analgesics, hypnotics and the use of locoregionalanaesthesia were linked to a decrease in mortality.Limitations:The limitations of the study include the non-randomised sam-ple, potential selection bias, lack of response rate quantification, variable dataquality control, subjectivity in classifying causes of death and limited analysisof variables.Conclusion:Careful patient evaluation, drug selection and monitoring canbe associated with reduced mortality. These findings can be used to developguidelines and strategies to improve patient safety and outcomes. Furtherresearch is needed to refine protocols, enhance data quality systems andexplore additional risk mitigation measures.

When fuel cells are used to power mobile applications, such a vehicles, hybridization with batteries is normally required. Depending on the electronic coupling between the energy sources the power plants can have passive or active configurations. Hybrid fuel cell-battery power plants with active power control flow have some advantages. For example, they can decrease the total energy losses, while improving the fuel cell performance, extending its lifetime. Power plants with DC/DC converters show low specific energy ratios, but with a superior energy management. In the present research, the hybrid power plant for an unmanned aquatic surface vehicle (USV) based on a PEM fuel cell and a Li-ion battery is developed. Active (with DC–DC converters) or passive architectures are analyzed by numerical simulations and experimental tests. Good results are obtained for the active power plant, where the peak power demands are managed by the battery pack while the fuel cell power remains constant thanks to the DC-converter control. The study shows that a simple control algorithm (no optimal) can help to extend the USV autonomy above 12 h in calm waters with a specific energy of 85.6 W h kg-1.

La pandemia Covid-19 supuso un fuerte impulso al teletrabajo y la formación virtual. El alumnado y el personal empleado tuvieron que desarrollar nuevas competencias para adaptarse al formato on-line. Ante esta situación, si bien han proliferado los estudios sobre los efectos de la pandemia tanto en el ámbito laboral como en el educativo, es poca la literatura acerca de su impacto en las prácticas curriculares. El presente estudio aborda el análisis, desde la perspectiva empresarial, de las competencias requeridas para la realización de teleprácticas eficaces. Se elaboró una encuesta exploratoria para conocer la opinión de las empresas que habían acogido estudiantes en prácticas on-line acerca de su intención de mantener esta modalidad en el futuro y de las competencias que más valoraban en su desempeño. A partir de esta, se ha realizado un análisis descriptivo de los resultados obtenidos, seguido de una prueba de proporciones Chi-Cuadrado. A continuación, se ha desarrollado un análisis factorial exploratorio y ejecutado un análisis de componentes principales (PCA). El objetivo era detectar relaciones de interdependencia entre las distintas competencias y, así, sintetizar la información mediante la creación de factores que las agrupan. Asimismo, se ha realizado un análisis cualitativo del contenido de la pregunta abierta sobre otras competencias requeridas. Los resultados del estudio introducen la singularidad competencial de las teleprácticas y permiten vislumbrar la necesidad de seguir investigando para crear un modelo eficaz que mejore la empleabilidad de los futuros egresados.

A prospective, experimental, randomized, double blinded study was designed to evaluate the effects of glycosaminoglycans, with or without native type II collagen (NC), in an osteoarthritis model induced by cranial cruciate ligament transection. The following compounds were tested: chondroitin sulfate (CS), glucosamine hydrochloride (GlHCl), hyaluronic acid (HA) and NC. Fiftyfour female 12-week-old New Zealand rabbits were classified into three groups: CTR (control–no treatment), CGH (CS + GlHCl + HA) and CGH-NC (CS + GlHCl + HA + NC). Each group was subdivided into three subgroups according to survival times of 24, 56 and 84 days. Over time, all rabbits developed degenerative changes associated with osteoarthritis. CGH-NC showed significantly improved values on macroscopic evaluation, compared to CTR and CGH. Microscopically, significantly better results were seen with CGH and CGH-NC, compared to CTR, and synovial membrane values were significantly better with CGH-NC compared to CGH. A significant improvement in magnetic resonance imaging biomarkers was also observed with CGH-NC in cartilage transversal relaxation time (T2) and subchondral bone D2D fractal dimension in the lateral condyle. In conclusion, our results show beneficial effects on joint health of CGH and CGH-NC and also supports that adding NC to CGH results in even greater efficacy.

Leading edge protection (LEP) coating systems are applied to protect turbine blade edges from rain erosion. The performance of a LEP system is assessed in an accelerated rain erosion test (RET) as a metric for industrial application, but these tests are expensive. Modelling methods are available to predict erosion, based on fundamental material properties, but there is a lack of validation. The Springer model (1976) is analysed in this work to assess it as a tool for using material fundamental properties to predict the time to failure in a rain erosion test. It has been applied, referenced and industry validated with important partial considerations. The method has been applied successfully for erosion damage by wear performance prediction when combined with prior material data from rain erosion test (RET), instead of obtaining it directly from fundamental properties measured separately as Springer proposed. The method also offers accurate predictions when coupled with modified numerical parameters obtained from experimental RET testing data. This research aims to understand the differences between the experimental data used by Springer and the current industry approach to rain erosion testing, and to determine how it may introduce inaccuracies into lifetime predictions of current LEP systems, since they are very different to those tested in the historic modelling validation. In this work, a review of the modelling is presented, allowing for the understanding of key issues of its computational implementation and the required experimental material characterisation. Modelling results are discussed for different original application issues and industry-related LEP configuration cases, offering the reader to interpret the limits of the performance prediction when considering the variation in material fundamental properties involved.

Achieving European climate neutrality by 2050 requires further efforts not only from the industry and society, but also from policymakers. The use of high-efficiency cogeneration facilities will help to reduce both primary energy consumption and CO2 emissions because of the increase in overall efficiency. Fuel cell-based cogeneration technologies are relevant solutions to these points for small- and microscale units. In this research, an innovative and new fuel cell-based cogeneration plant is studied, and its performance is compared with other cogeneration technologies to evaluate the potential reduction degree in energy consumption and CO2 emissions. Four energy consumption profile datasets have been generated from real consumption data of different dwellings located in the Mediterranean coast of Spain to perform numerical simulations in different energy scenarios according to the fuel used in the cogeneration. Results show that the fuel cell-based cogeneration systems reduce primary energy consumption and CO2 emissions in buildings, to a degree that depends on the heat-to-power ratio of the consumer. Primary energy consumption varies from 40% to 90% of the original primary energy consumption, when hydrogen is produced from natural gas reforming process, and from 5% to 40% of the original primary energy consumption if the cogeneration is fueled with hydrogen obtained from renewable energy sources. Similar reduction degrees are achieved in CO2 emissions.

The objective of this retrospective study was to review the results of a 4-year audit performed on anesthetic machines and vaporizers used in veterinary clinics in Spain and Portugal. Data was collected between July 2016 and April 2020. Inspections were carried out by a team of seven veterinarians, using a human-modified system of checks that was adapted to a veterinary practice. The evaluation of each item was noted as “correct” or “incorrect”. The vaporizers’ performance was evaluated using a self-calibrating gas analyzer. The vaporizer was classified as “correct” or “incorrect” when the vaporization error was less than or equal to, or more than 20%, respectively. The anesthetic machine was classified as “conforming” if all its components were noted as “correct” and no leaks were detected, or as “non-conforming” if any of the components was noted as “incorrect” or if a leak was detected. If the inspector was able to repair on-site the item malfunctions detected and the machine was fit for use, they issued a final report as “conforming.” On the contrary, if such malfunctions persisted, the final report was “non-conforming,” and a recommendation to remove the machine from service until its final repair was provided. To perform statistical analysis, each inspected item was used as predictor, classification and regression trees were built, and a random forest analysis was performed. A total of 2,001 anesthetic machines and 2,309 vaporizers were studied. After inspection, 42.7 and 26.4%of the machines were non-conforming and conforming, respectively, whereas 30.9%could be repaired in situ. A total of 27.1%of the isoflurane vaporizers and 35.9%of the sevoflurane vaporizers were incorrect. Machine learning techniques showed that the most important variables in the classification of the anestheticmachines as conforming or non-conforming were mostly the scavenger system and the canister, followed some way behind by the APL valve, source of oxygen, reservoir bag, vaporizer, and connections.

Under droplet impingement, surface leading edge protection (LEP) coating materials for wind turbine blades develop high-rate transient pressure build-up and a subsequent relaxation in a range of strain rates. The stress-strain coating LEP behavior at a working frequency range depends on the specific LEP and on the material and operational conditions, as described in this research in a previous work. Wear fatigue failure analysis, based on the Springer model, requires coating and substrate speed of sound measurements as constant input material parameters. It considers a linear elastic response of the polymer subjected to drop impact loads, but does not account for the frequency dependent viscoelastic e ects for the materials involved. The model has been widely used and validated in the literature for di erent liquid impact erosion problems. In this work, it is shown the appropriate definition of the viscoelastic materials properties with ultrasonic techniques. It is broadly used for developing precise measurements of the speed of sound in thin coatings and laminates. It also allows accurately evaluating elastic moduli and assessing mechanical properties at the high frequencies of interest. In the current work, an investigation into various LEP coating application cases have been undertaken and related with the rain erosion durability factors due to suitable material impedance definition. The proposed numerical procedures to predict wear surface erosion have been evaluated in comparison with the rain erosion testing, in order to identify suitable coating and composite substrate combinations. LEP erosion performance at rain erosion testing (RET) technique is used widely in the wind industry as the key metric, in an e ort to assess the response of the varying material and operational parameters involved.

Top coating are usually moulded, painted or sprayed onto the wind blade Leading-Edge surface to prevent rain erosion due to transverse repeated droplet impacts. Wear fatigue failure analysis based on Springer model has been widely referenced and validated to quantitatively predict damage initiation. The model requires liquid, coating and substrate speed of sound measurements as constant input parameters to define analytically the shockwave progression due to their relative vibro-acoustic properties. The modelling assumes a pure elastic material behavior during the impact event. Recent coating technologies applied to prevent erosion are based on viscoelastic materials and develop high-rate transient pressure build-up and a subsequent relaxation in a range of strain rates. In order to analyze the erosion performance by using Springer model, appropriate impedance characterization for such viscoelastic materials is then required and represents the main objective of this work to avoid lack of accuracy. In the first part of this research, it is proposed a modelling methodology that allows one to evaluate the frequency dependent strain-stress behavior of the multilayer coating system under single droplet impingement. The computational tool ponders the operational conditions (impact velocity, droplet size, layer thickness, etc.) with the appropriate variable working frequency range for the speed of sound measurements. The second part of this research defines in a complementary paper, the ultrasonic testing characterization of di erent viscoelastic coatings and the methodology validation. The modelling framework is then used to identify suitable coating and substrate combinations due to their acoustic matching optimization and to analyze the anti-erosion performance of the coating protection system.