•The efficiency of a PV installation in low irradiance periods was improved.•We simulated the MODEN system in five European locations.•We apply MODEN efficiency improvement system to a real ...photovoltaic plant.
This paper proposes an Energy Modulation strategy (MODEN) which allows the PV inverters efficiency to be incremented in low input power condition. The key element is the utilization of an ultracapacitors bank as energy regulation transitory element: in low irradiance condition, the energy coming from the PV array is not converted immediately, but temporary stored to be converted at a power regime in which the inverter may have maximum yield. In this paper the simulator developed, the guidelines for the MODEN system design optimization, and the simulation results, are described. It is also described the prototype fabricated and installed in a PV plant, and its performance evaluated.
Different learning methods such as project-based learning, spiral learning and peer assessment have been implemented in science disciplines with different outcomes. This paper presents a proposal for ...a project management course in the context of a computer science degree. Our proposal combines three well-known methods: project-based learning, spiral learning and peer assessment. Namely, the course is articulated during a semester through the structured (progressive and incremental) development of a sequence of four projects, whose duration, scope and difficulty of management increase as the student gains theoretical and instrumental knowledge related to planning, monitoring and controlling projects. Moreover, the proposal is complemented using peer assessment. The proposal has already been implemented and validated for the last 3 years in two different universities. In the first year, project-based learning and spiral learning methods were combined. Such a combination was also employed in the other 2 years; but additionally, students had the opportunity to assess projects developed by university partners and by students of the other university. A total of 154 students have participated in the study. We obtain a gain in the quality of the subsequently projects derived from the spiral project-based learning. Moreover, this gain is significantly bigger when peer assessment is introduced. In addition, high-performance students take advantage of peer assessment from the first moment, whereas the improvement in poor-performance students is delayed.
Arc discharge single-walled carbon nanotubes (SWCNTs) were modified through different oxidative treatments and functionalization reactions. The modified SWCNT powders were dispersed in four different ...aqueous media and purified by ultracentrifugation. Extinction coefficients of the modified SWCNTs depended on the SWCNT type but did not depend on the dispersion medium. According to visible/near infrared spectroscopy, the purity of all the modified SWCNT dispersions substantially improved after ultracentrifugation; however, the spectrum profile, the degree of purity and the centrifugation yield were influenced by the SWCNT type, the surface functional groups and the dispersion medium. Semi-quantitative purity indexes calculated from optical absorption spectra were supported by transmission electron microscopy observations. Contents in metal impurities were analyzed by energy dispersive X-ray spectroscopy. SWCNT samples processed by oxidative acid treatments and ultracentrifugation showed metal contents of lower than 0.5wt%.
The usual supplementation for hypothyroidism is based on monotherapy with levothyroxine. However, some patients persist with symptoms attributable to the deficit of thyroid hormone. It has been ...suggested that the a combined treatment with liothyronine and levothyroxine would provide a greater benefit.
We searched in Epistemonikos, the largest database of systematic reviews in health, which is maintained by screening multiple information sources, including MEDLINE, EMBASE, Cochrane, among others. We extracted data from the systematic reviews, reanalyzed data of primary studies, conducted a meta-analysis and generated a summary of findings table using the GRADE approach.
We identified three systematic reviews including twelve primary studies overall, all of which were randomized trials. We concluded that the addition of liothyronine to the treatment of hypothyroidism has minimal or no effect on fatigue and quality of life. It probably does not improve mood, pain or function cognitive, and it would not reduce body weight.
To determine whether the β-lactam allergy delabeling was safe and cost-saving in Primary Care (PC) patients.
We have conducted a retrospective chart review of PC patients with β-lactam allergy label ...evaluated in our Allergy Unit between 2017 and 2022.
Allergy Department. Hospital Virgen del Rocio (Sevilla).
A total of 391 patients labeled for β-lactam allergy in PC were studied.
(a) Outcome evaluation of a β-lactam allergy delabeling procedure. (b) A ratio between the total e-prescribed antibiotic cost and the number of treatment days (the experimental daily antibiotic cost or EDAC) before and after delabeling was analyzed in delabeled and truly allergic patients.
The results of skin testing were positive in 9.2% of the reported cases (36 of 391 patients). The reactions to oral provocation challenge (OPC) occurred in 2.14% of the patients who underwent negative skin testing to offending β-lactam (in 15 of 699 OPC). A total of 307 patients (78.5%) were delabeled; 70 (17.9%) had a β-lactam selective response and 14 (3.59%) reacted to both penicillin and cephalosporin. The EDAC before and after the procedure in delabeled patients was significantly lower (0.88 € vs 0.62 €, p<10−3), than that observed in truly allergic group (0.87 € vs. 0.76 €, p=not significant).
To delabel β-lactam allergy in Primary Care patients is safe in most patients, cost-saving in antibioticotherapy, and allows identify the main clinical β-lactam allergy phenotypes that benefit from this procedure.
Evaluar la seguridad del desetiquetado de alergia a β-lactámicos y su impacto económico en la prescripción antibiótica en atención primaria (AP).
Estudio observacional retrospectivo en situación de práctica clínica habitual.
Unidad de Alergología, Hospital Virgen del Rocío, Sevilla.
391 pacientes etiquetados de alergia a β-lactámicos en AP.
a) Evaluación de un procedimiento de desetiquetado de alergia a β-lactámicos. b) Se analizó la relación entre el coste total del antibiótico e-prescrito y el número de días de tratamiento (el coste diario antibiótico experimental the experimental daily antibiotic cost, EDAC).
Las pruebas cutáneas a β-lactámicos fueron positivas en el 9,2% de casos (36 de 391 pacientes). Las reacciones durante la provocación oral controlada ocurrieron en el 2,14% de casos con pruebas cutáneas negativas a β-lactámicos (en 15 de 699 provocaciones). Un total de 307 pacientes (78,5%) fueron desetiquetados; 70 (17,9%) tuvieron una respuesta selectiva a un β-lactámico y 14 (3,59%) reaccionaron tanto a penicilina como a cefalosporina. El EDAC antes y después del procedimiento en los pacientes desetiquetados fue significativamente menor (0,88€ versus 0,62€, p<10−3), al observado en el grupo de pacientes alérgicos (0,87€ versus 0,76€, p no significativo).
Desetiquetar la alergia a β-lactámicos en pacientes de AP es seguro en la mayoría de los pacientes, ahorra costes en antibioterapia y permite identificar los principales fenotipos clínicos de alergia a β-lactámicos que se benefician de este procedimiento.
Dietary-nutritional needs in tennis: A narrative review Domínguez, Raúl; Sánchez Oliver, Antonio Jesús; Fernandes da Silva, Sandro ...
Revista española de nutrición humana y dietética,
01/2021, Letnik:
25, Številka:
1
Journal Article
Odprti dostop
Introduction: Tennis is characterized by a large number of competitions and little recovery time between them. Thus, tennis players and coaching staff have become interested in the role that ...nutrition can play in maximizing sports performance. The scientific literature does not have recent narrative and/or systematic reviews about to nutrition in tennis. The aim of this study is to map, describe and discuss the state of the science of nutrition and dietetic practices for tennis players from a theoretical and contextual point of view, to enable focused future systematic reviews.Material and methods: A narrative review through the Dialnet, Elsevier, Medline, Pubmed and Web of Science databases, through a search strategy based on keywords separated by Boolean connectors. A series of inclusion / exclusion criteria were applied to select those investigations that responded to the aim of the work.Results: Nutritional recommendations on carbohydrate intake depend on the training load, 5-7 g/kg/day g/kg/day for normal training and 7-10 g/kg/day for competitive periods or high training load. The recommended protein intake is 1.8 g/kg/day and 1 g/kg/day of lipids. The supplements that can optimize tennis performance are caffeine, sodium bicarbonate, creatine and β-alanine. Beetroot juice can be a possible aid to consider in dietetic-nutritional planning in tennis players.Conclusions: Performance and health of tennis player can be optimized, as well as adequate periodization of nutrients and supplements, meeting to the physiological demands of tennis.
Introduction
Multiple sclerosis (MS) is a heterogeneous disease with an unpredictable course. Visual pathway is a target of the disease and may reflect mechanisms that lead to disability. Structural ...and functional changes in the visual pathway may be studied by noninvasive techniques such as optical coherence tomography (OCT), visual evoked potentials (VEP), or B‐mode transorbital sonography (TOS).
Objectives
The aim is to assess changes in the visual pathway in eyes of MS patients with and without a history of optic neuritis over a 3‐year period and to explore their relationship with disability.
Materials and Methods
In total, 112 eyes from 56 patients with relapsing MS were recruited: 29 with, and 83 without a history of ON (hON and nhON, respectively). Several parameters were measured by OCT, VEP, and TOS. Baseline measurements were also compared to 29 healthy controls. At 36 months, measurements were repeated in all eyes.
Results
At baseline, all tests showed significant differences in optic nerve structure and function in both patient cohorts in all the parameters studied, suggestive of more impairment of the visual pathway among the hON cohort. OCT showed significant differences between healthy controls and the nhON cohort. At 36 months, the nhON cohort showed significant changes by OCT, VEP, and TOS suggestive of further visual pathway impairment. OCT measurements also correlated with baseline EDSS among the nhON cohort.
Conclusions
OCT is the most suitable technique and outperforms VEP and TOS to detect subclinical damage in the visual pathway. It discriminated MS patients from healthy controls and showed a progressive decline in optic nerve thickness over time among these patients.
We assesed the visual pathway in MS patients for 3 years using optical coherence tomography (OCT), visual evoked potentials and transorbital sonography. All techniques showed impairment of visual pathway over time and OCT resulted the best to detect subclinical damage.
3D porous graphene microarchitectures with aligned and continuous channels are of paramount interest for several applications such as pollutant removal, energy storage, or biomedical engineering. For ...these applications, an accurate control over the pore microstructure is of capital importance. Freeze casting is a well-stablished technique to prepare graphene aerogels with unidirectional channels. This technique is typically applied to plain GO colloids, leading to discontinuous microchannels. Herein we have carried out the freeze process starting directly with partially reduced graphene (rGO) hydrogels prepared by a prior hydrothermal treatment in autoclave. This approach leads to the formation of aerogels with aligned and continuous microchannels, enabled by an intermediate cross-linking degree of the rGO nanosheets, carefully controlled by keeping the time of the prior hydrothermal process between the thresholds of 45–75 min. To the best of our knowledge, the effect of the degree of cross-linking in the freeze casting process is not yet reported. The resulting rGO aerogels with highly aligned microchannel structure reveal superior properties over its isotropic counterpart of randomly oriented pores for the absorption of nonpolar solvents and the selective adsorption of an aromatic compound dissolved in an alkane. Our combined hydrothermal freeze casting approach thus affords aligned microchannel rGO aerogels of enormous potential for environmental remediation.
This work reports the synthesis of single‐wall carbon nanotubes (SWCNT) covalently functionalized with polylysine (Plys) and the analytical performance of glassy carbon electrodes (GCE) modified with ...this material (GCE/SWCNT‐Plys). The resulting electrodes showed an important decrease in the overvoltages for the oxidation of ascorbic acid, uric acid and hydrogen peroxide as well as for the reduction of hydrogen peroxide. The favorable interaction of glucose oxidase (GOx) with SWCNT‐Plys allowed the sensitive and selective glucose biosensing at −0.100 V without any permselective membrane. The proposed sensor was challenged with different real samples without pretreatment showing an excellent correlation with the reported values.
Improving the protection of concrete by applying graphene oxide (GO) as a surface treatment has become the objective of the present study. This study focuses on performing a statistical analysis to ...study different levels of GO application as an exterior coating, thus observing the effectiveness of the coating and the optimization of the treatment material for concrete protection. Four tests were performed to define concrete durability, such as pressurized water penetration, capillary absorption, freeze-thaw resistance and carbonation resistance. The results showed an increase in concrete durability with any level of GO application on the surface, considering that the optimum amount of application for water impermeability and freeze-thaw resistance is 26.2 µg/cm2, since it was possible to reduce pressurized water penetration by 45%, capillary water absorption by 57% and freeze-thaw detachment by 25%. However, the optimum application rate for carbonation resistance is 52.4 µg/cm2, reducing carbonation by almost 60%. In conclusion, if the concrete is going to be exposed to less aggressive environments, the application of a mild surface coating of GO is sufficient for its protection, and if the concrete is going to be exposed to more aggressive environments, it is necessary to increase the amount of GO. The performance of GO as a coating significantly increased the degree of protection of the concrete, increasing its service life and proving to be a promising treatment for concrete surface protection.
PDF
