101 research outputs found
Dynamic Modelling and Techno-Economic Assessment of a Compressed Heat Energy Storage System: Application in a 26-MW Wind Farm in Spain
[EN] One of the main challenges for a further integration of renewable energy sources in the electricity grid is the development of large-scale energy storage systems to overcome their intermittency. This paper presents the concept named CHEST (Compressed Heat Energy STorage), in which the excess electricity is employed to increase the temperature of a heat source by means of a high-temperature heat pump. This heat is stored in a combination of latent and sensible heat storage systems. Later, the stored heat is used to drive an organic Rankine cycle, and hereby to produce electricity when needed. A novel application of this storage system is presented by exploring its potential integration in the Spanish technical constraints electricity market. A detailed dynamic model of the proposed CHEST system was developed and applied to a case study of a 26-MW wind power plant in Spain. Different capacities of the storage system were assessed for the case under study. The results show that roundtrip efficiencies above 90% can be achieved in all the simulated scenarios and that the CHEST system can provide from 1% to 20% of the total energy contribution of the power plant, depending on its size. The CHEST concept could be economically feasible if its capital expenditure (CAPEX) ranges between 200 and 650 k€/MWThis work has been partially funded by the grant agreement No. 764042 (CHESTER project) of the European Union's Horizon 2020 research and innovation program.Sánchez Canales, V.; Payá-Herrero, J.; Corberán, JM.; Hassan, A. (2020). Dynamic Modelling and Techno-Economic Assessment of a Compressed Heat Energy Storage System: Application in a 26-MW Wind Farm in Spain. Energies. 13(18):1-18. https://doi.org/10.3390/en13184739S1181318Nikolaou, T., Stavrakakis, G. S., & Tsamoudalis, K. (2020). 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Applied Thermal Engineering, 121, 1051-1058. doi:10.1016/j.applthermaleng.2017.04.127Mateu-Royo, C., Mota-Babiloni, A., Navarro-Esbrí, J., Peris, B., Molés, F., & Amat-Albuixech, M. (2019). Multi-objective optimization of a novel reversible High-Temperature Heat Pump-Organic Rankine Cycle (HTHP-ORC) for industrial low-grade waste heat recovery. Energy Conversion and Management, 197, 111908. doi:10.1016/j.enconman.2019.111908Benato, A. (2017). Performance and cost evaluation of an innovative Pumped Thermal Electricity Storage power system. Energy, 138, 419-436. doi:10.1016/j.energy.2017.07.066Benato, A., & Stoppato, A. (2019). Integrated Thermal Electricity Storage System: Energetic and cost performance. Energy Conversion and Management, 197, 111833. doi:10.1016/j.enconman.2019.111833Maximov, S., Harrison, G., & Friedrich, D. (2019). Long Term Impact of Grid Level Energy Storage on Renewable Energy Penetration and Emissions in the Chilean Electric System. Energies, 12(6), 1070. doi:10.3390/en12061070Steinmann, W. D. (2014). The CHEST (Compressed Heat Energy STorage) concept for facility scale thermo mechanical energy storage. Energy, 69, 543-552. doi:10.1016/j.energy.2014.03.049Hu, B., Wu, D., Wang, L. W., & Wang, R. Z. (2017). Exergy analysis of R1234ze(Z) as high temperature heat pump working fluid with multi-stage compression. Frontiers in Energy, 11(4), 493-502. doi:10.1007/s11708-017-0510-6He, Y.-L., Wang, R., Roskilly, A. P., & Li, P. (2017). Efficient use of waste heat and solar energy: Technologies of cooling, heating, power generation and heat transfer. Frontiers in Energy, 11(4), 411-413. doi:10.1007/s11708-017-0525-zHassan, A. H., O’Donoghue, L., Sánchez-Canales, V., Corberán, J. M., Payá, J., & Jockenhöfer, H. (2020). Thermodynamic analysis of high-temperature pumped thermal energy storage systems: Refrigerant selection, performance and limitations. 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Energies, 12(6), 1045. doi:10.3390/en12061045Estadísticas del Sistema Eléctrico | Red Eléctrica de Españahttps://www.ree.es/es/estadisticas-del-sistema-electrico/3015/3001OMIP Operador del Mercado Ibérico de Energía—Polo Portuguéshttps://www.omip.pt/El Mercado de Restricciones Técnicashttp://mifacturadeluz.com/mercado-de-restricciones-tecnicas/Puerto Escandón (España)—Parques eólicos—Acceso en línea—The Wind Powerhttps://www.thewindpower.net/windfarm_es_2253_puerto-escandon.phpFederico Bava DS D2.1 Case studies: User Requirements and Boundary Conditions Definition. CHESTERhttps://www.chester-project.eu/wp-content/uploads/2018/11/CHESTER_D2.1_Case-Studies_v5.0.pdfEstado actual de la energía termosolar (CSP)—HELIONOTICIAShttp://helionoticias.es/estado-actual-de-la-energia-termosolar-csp/Gallo, A. B., Simões-Moreira, J. R., Costa, H. K. M., Santos, M. M., & Moutinho dos Santos, E. (2016). Energy storage in the energy transition context: A technology review. 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Dermatoses in Latin American immigrants seen in a tertiary hospital
Europe, and in particular Spain, has become the destination of a considerable number of immigrants, 50% come from Latin America. The purpose of this study was to describe the cases of dermatoses seen in the immigrant Latin American population and compare them with those found in the control Spanish population. Over a year all the visits of economic immigrants seen in the Dermatology Section of the Hospital General Universitario de Alicante were prospectively recorded. During the study period 706 Latin American patients were seen. The most frequent dermatoses were eczema (18.2%), acne (6.5%) and non-genital viral warts (6.3%). The comparative study of dermatoses adjusted for age and sex, found a greater frequency of eczema, alopecia, melasma, herpes simplex, pilar keratosis, xerosis, and scabies (p < 0.01) in the Latin American population. On the other hand, melanocytic nevi and melanoma were less frequent in these patients (p < 0.05). We may say that the skin type and socio-sanitary conditions of the Latin American immigrant population lead to a greater frequency of eczema, melasma and scabies. In addition, the skin type and younger age favour a lower frequency of skin tumours
The Determination of Total Testosterone and Free Testosterone (RIA) are not Applicable to the Evaluation of Gonadal Function in HIV-Infected Males
Introduction: Hypogonadism is common in human immunodeficiency virus (HIV)-infected men; the high concentration of sex hormone binding globulin (SHBG) in this population, induces a "false increase" in total testosterone (TT) values.Aims: To validate the determination of TT and measured free testosterone (FT [radioimmunoassay {RIA}]) for hypogonadism diagnosis in an HIV-infected population using calculated free testosterone (CFT) as reference method; and also to determine the prevalence and identify the risks factors of hypogonadism.Methods: Cross-sectional, observational study. Ninety HIV-infected males (42 ± 8.2 years), not HCV coinfected, antiretroviral therapy (ART)-naive (14 patients), on current ART with enhanced protease inhibitor (PI) (39 patients), or patients on PI-naive ART (NN) (37 patients).Main outcome measures: CFT was calculated by determining TT, SHBG, and albumin (Vermeulen's formula); hypogonadism was defined as CFT <0.22 nmol/L (reference range for young healthy males in our laboratory); sensitivity of TT and FT (RIA) for hypogonadism diagnosis was calculated.Results: Twelve patients (13.3%, 95% confidence interval [CI] 7.8-21.9) by CFT presented hypogonadism. TT and FT (RIA) presented a sensitivity of less than 30% in the diagnosis of hypogonadism. Logistic regression multivariate analysis confirmed an independent association between hypogonadism, the patient's age per decade, odds ratio (OR) 6.9 (CI 1.9-24.8; P = 0.003), and longer duration of HIV infection per decade, OR 13.1 (CI 1.3-130.6; P = 0.02). Hypogonadism was associated with erectile dysfunction.Conclusions: TT and FT (RIA) are not useful in the differential diagnosis of hypogonadism in HIV-infected males. There is a significant prevalence of hypogonadism in HIV-infected males, with the patient's age and duration of the disease being the only identifiable risk factors
The Waning of BNT162b2 Vaccine Effectiveness for SARS-CoV-2 Infection Prevention over Time: A Test-Negative Study in Health Care Professionals of a Health Department from January 2021 to December 2021
The duration of protection of vaccines against SARS-CoV-2 infection has been evaluated in previous studies, but uncertainty remains about the persistence of effectiveness over time and the ideal timing for booster doses. Therefore, the aim of this study was to evaluate BNT162b2 vaccine effectiveness against SARS-CoV-2 infection in health care workers (HCWs) at a tertiary hospital depending on time elapsed since the completion of a two-dose vaccination regimen. We conducted a case–control with negative test study between 25 January and 12 December 2021 that included 1,404 HCWs who underwent an active infection diagnostic test (AIDT) to rule out SARS-CoV-2 infection due to COVID-19 suspicion or prior close contact with patients diagnosed with COVID-19. The adjusted vaccine effectiveness (aVE) for the prevention of SARS-CoV-2 infection 12 to 120 days after completing the full two-dose vaccination regimen was 91.9%. Then, aVE decreased to 63.7% between 121 to 240 days after completing the full two-dose regimen and to 37.2% after 241 days since the second dose. Vaccination against SARS-CoV-2 infection in HCWs remains highly effective after 12 to 120 days have elapsed since the administration of two doses of the BNT162b2 vaccine; however, effectiveness decreases as time elapses since its administration
Experience with tocilizumab in severe COVID-19 pneumonia after 80 days of follow-up: A retrospective cohort study
Objectives: To describe the clinical characteristics and predictors of major outcomes in patients treated with tocilizumab (TCZ) for severe COVID-19 pneumonia.Patients and methods: Case series of all sequential patients with severe COVID-19 pneumonia treated with TCZ at an Academic Spanish hospital (March 12 - May 2, 2020). Clinical outcomes: death, length of hospital stay. An early clinical response to TCZ (48-72 h after the administration) was assessed by variations in respiratory function markers, Brescia COVID Respiratory Severity Scale (BCRSS), inflammatory parameters, and patients' and physicians' opinion. Associations were tested by multiple logistic regression.Results: From a cohort of 236 patients, 77 patients treated with TCZ were included (median age 62 years (IQR 53.0-72.0), 64.9% were males), 42.9% had Charlson index ≥3; hypertension (41.6%), obesity (34.7%), and diabetes (20.8%). Median follow-up was 83.0 days (78.0-86.5), no patient was readmitted. ICU admission was required for 42 (54.5%), invasive mechanical ventilation in 38 (49.4%) and 10 patients died (12.9% global, 23.8% at ICU admitted). After multivariate adjustment, TCZ response by BCRSS (OR 0.03 (0.01-0.68), p = 0.028), and Charlson index (OR 3.54 (1.20-10.44), p = 0.022) has been identified as independent factors associated with mortality. Median of hospital stay was 16.0 days (11.0-23.0); BCRSS, physician subjective and D-dimer response were associated with shorter hospitalization stay.Conclusions: In a Mediterranean cohort, use of tocilizumab for severe COVID-19 show 12.9% of mortality. Early TCZ-response by BCRSS and low comorbidity were associated with increased survival. Early TCZ-response was related to shorter median hospital stay
Circulating nitrate-nitrite reduces oxygen uptake for improving resistance exercise performance after rest time in well-trained CrossFit athletes
This study aimed to determine the effects of circulating nitrate plus nitrite (NOx) concentrations on resistance exercise performance, VO2 and biomarkers of muscle damage. Eleven well-trained male CrossFit athletes (29.2 ± 3.7 years, 78.9 ± 5.4 kg, 175.1 ± 6.3 cm) carried out a resistance exercise test after drinking 140 mL of beetroot juice (BJ) or placebo. The test consisted of repeating the same resistance exercise routine twice: wall ball shots plus full back squat with 3-min rest (1st routine) or without rest (2nd routine) between the two exercises. Higher NOx plasma levels were verified after BJ than placebo in the pretest and post-test (p < 0.001). A higher number of repetitions was observed after BJ intake compared to placebo in the full back squat exercise during the first routine (p = 0.004). A significantly reduced VO2 was detected after BJ intake compared to placebo during rest and full back squat execution in the first routine (p < 0.05). Plasma myoglobin concentrations were significantly increased with BJ compared to placebo (p = 0.036). These results showed that plasma NOx levels reduced VO2 after BJ intake during rest time. These reduced VO2 was a key factor for improving full back squat performance during the first routine
Impact of COVID-19 on the degree of compliance with hand hygiene: a repeated cross-sectional study
Hand hygiene (HH) is the paramount measure used to prevent healthcare associated infections. A repeated cross-sectional study was undertaken with direct observation of the degree of compliance on HH of healthcare personnel during the SARS-CoV-2 pandemic. Between, 2018-2019, 9,083 HH opportunities were considered, and 5,821 in 2020-2022. Chi squared tests were used to identify associations. The crude and adjusted odds ratios were used along with a logistic regression model for statistical analyses. Compliance on HH increased significantly (p < 0.001) from 54.5% (95% CI: 53.5, 55.5) to 70.1% (95% CI: 68.9, 71.2) during the COVID-19 pandemic. This increase was observed in four of the five key moments of HH established by the World Health Organization (WHO) (p<0.05), except at moment 4. The factors that were significantly and independently associated with compliance were the time period considered, type of healthcare-personnel, attendance at training sessions, knowledge of HH and WHO guidelines, and availability of hand disinfectant alcoholic solution in pocket format. Highest HH compliance occurred during the COVID-19 pandemic, reflecting a positive change in healthcare-personnel’s behavior regarding HH recommendations.We received funding through the Alicante Institute for Health and Biomedical Research (ISABIAL) plan for scientific and technical research and innovation project number 2021-0392
Immunological response against SARS-CoV-2 following full-dose administration of Comirnaty® COVID-19 vaccine in nursing home residents
Objectives: The current study was aimed at examining SARS-CoV-2 immune responses following two
doses of Comirnaty® COVID-19 vaccine among elderly people in nursing homes.
Methods: A prospective cohort study in a representative sample from nursing homes in Valencia
(n ¼ 881; males: 271, females 610; median age, 86 years) recruited residents using a random one-stage
cluster sampling approach. A lateral flow immunochromatography device (LFIC) (OnSite COVID-19 IgG/
IgM Rapid Test; CTK BIOTECH, Poway, CA, USA) was used as the front-line test for detecting SARS-CoV-2-
Spike (S)-specific antibodies in whole blood obtained using a fingerstick. Residents returning negative
LFIC results underwent venipuncture and testing for presence of SARS-CoV-2-S-reactive antibodies and T
cells using the Roche Elecsys® Anti-SARS-CoV-2 S (Roche Diagnostics, Pleasanton, CA, USA), the
LIAISON® SARS-CoV-2 TrimericS IgG assay (Diasorin S.p.A, Saluggia, Italy) and by flow cytometry,
respectively.
Results: The SARS-CoV-2-S antibody detection rate in nursing home residents was 99.6% (283/284) and
98.3% (587/597) for SARS-CoV-2 recovered and naïve residents, respectively, within a median of 99 days
(range 17e125 days) after full vaccination. Three out of five residents lacking SARS-CoV-2-S antibodies
had detectable S-reactive CD8þ and/or CD4þ T cells. In addition, 50/50 and 40/50 participants with
detectable SARS-CoV-2 antibodies also had SARS-CoV-2-S-reactive interferon-g-producing CD4þ and
CD8þ T cells, respectivelyMedicin
Etiology of bloodstream infections at a population level during 2013-2017 in the Autonomous Community of Valencia, Spain
ABSTRACT: Introduction: Bloodstream Infections has become in one of the priorities for the antimicrobial stewardship teams due to their high mortality and morbidity rates. Usually, the first antibiotic treatment for this pathology must be empirical, without microbiology data about the microorganism involved. For this reason, the population studies about the etiology of bacteremia are a key factor to improve the selection of the empirical treatment, because they describe the main microorganisms associated to this pathology in each area, and this data could facilitate the selection of correct antibiotic therapy.
Material and methods: This study describes the etiology of bloodstream infections in the Southeast of Spain. The etiology of bacteremia was analysed by a retrospective review of all age-ranged patients from every public hospital in the Autonomous Community of Valencia (approximately 5,000,000 inhabitants) for five years.
Results: A total of 92,097 isolates were obtained, 44.5% of them were coagulase-negative staphylococci. Enterobacteriales was the most prevalent group and an increase in frequency was observed along the time. Streptococcus spp. were the second microorganisms more frequently isolated. Next, the most prevalent were Staphylococcus aureus and Enterococcus spp., both with a stable incidence along the study. Finally, Pseudomonas aeruginosa was the fifth microorganism more frequently solated.
Conclusions: These data constitute a useful tool that can help in the choice of empirical treatment for bloodstream infections, since the knowledge of local epidemiology is key to prescribe a fast and appropriate antibiotic therapy, aspect capital to improve survival.RESUMEN: Introducción: Las bacteriemias se han convertido en una de las prioridades de los Programas de Optimización de uso de Antimicrobianos (PROA) debido a sus altas tasas de morbimortalidad. Normalmente, el tratamiento antibiótico tiene que ser pautado de forma empírica, sin datos del microorganismo implicado. Por esto, los estudios poblacionales sobre la etiología de las bacteriemias son un factor clave para mejorar la elección del tratamiento empírico, ya que describen los principales microorganismos asociados a esta patología en cada área, lo que facilita en gran medida la selección del antibiótico
correcto. Material y métodos: Este estudio describe la etiología de las bacteriemias en el sureste de España durante los años 2013-2017. La etología fue analizada de forma retrospectiva estudiando los microorganismos implicados en todas las bacteriemias diagnosticadas en la Comunidad Valenciana (5.000.000 de habitantes). Resultados. Se obtuvieron un total de 92.097 aislados clínicos, de los cuales un 44,5% fueron Staphylococcus coa-gulasa negativos. Las enterobacterias fueron el grupo más prevalente, su frecuencia se incrementó durante el estudio. Los cocos grampositivos, tipo Streptococcus, fueron los siguientes microorganismos que se aislaron de forma más frecuente, su frecuencia disminuyó a lo largo del periodo estudiado. A continuación, Staphylococcus aureus y Enterococcus spp. les siguieron en prevalencia, manteniéndose sus tasas estables a lo largo del estudio. Por último, el quinto microorganismo más prevalente fue Pseudomonas aeruginosa. Conclusiones: Los datos obtenidos en este estudio constituyen una herramienta que puede facilitar la elección correcta del tratamiento empírico inicial que debe aplicarse en estos procesos
Validity of CSF alpha-synuclein to predict psychosis in prodromal Alzheimer's disease
BackgroundAlzheimer's disease (AD) accompanied by psychotic symptoms (PS) has a poor prognosis and may be associated with imbalances in key neural proteins such as alpha-synuclein (AS).AimThe aim of the study was to evaluate the diagnostic validity of AS levels in the cerebrospinal fluid (CSF) as a predictor of the emergence of PS in patients with prodromal AD.Materials and methodsPatients with mild cognitive impairment were recruited between 2010 and 2018. Core AD biomarkers and AS levels were measured in CSF obtained during the prodromal phase of the illness. All patients who met the NIA-AA 2018 criteria for AD biomarkers received treatment with anticholinesterasic drugs. Follow-up evaluations were conducted to assess patients for the presence of psychosis using current criteria; the use of neuroleptic drugs was required for inclusion in the psychosis group. Several comparisons were made, taking into account the timing of the emergence of PS.ResultsA total of 130 patients with prodromal AD were included in this study. Of these, 50 (38.4%) met the criteria for PS within an 8-year follow-up period. AS was found to be a valuable CSF biomarker to differentiate between the psychotic and non-psychotic groups in every comparison made, depending on the onset of PS. Using an AS level of 1,257 pg/mL as the cutoff, this predictor achieved at least 80% sensitivity.ConclusionTo our knowledge, this study represents the first time that a CSF biomarker has shown diagnostic validity for prediction of the emergence of PS in patients with prodromal AD
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