Dairy Debaryomyces hansenii strains produce the antihypertensive casein-derived peptides LHLPLP and HLPLP

The ability of dairy Debaryomyces hansenii, Kluyveromyces lactis and Kluyveromyces marxianus strains to release the casein-derived antihypertensive sequences RYLGY, AYFYPEL, LHLPLP, HLPLP, VPP and/or IPP was examined. Yeast strains were grown in medium with casein as sole nitrogen source and the yeast casein hydrolysates (CSHs) were analysed by HPLC-MS/MS to search for the six antihypertensive sequences. Only LHLPLP and HLPLP were identified in CSHs and exclusively in D. hansenii Dh1 and Dh14 hydrolysates in which both antihypertensive sequences represented approximately 6 (CSH Dh1) and 10% (CSH Dh14) of total peptide content. In addition, a complete analysis of selected CSHs by HPLC-MS/MS allowed the identification of 35 (Dh1) and 46 (Dh14) additional peptides, which could also contribute to the observed in vitro ACE inhibitory potency of both hydrolysates (Dh1, IC50 = 13.6 ± 1.8 μg/mL; Dh14, IC50 = 17.5 ± 2.1 μg/mL) and might confer them multifunctional properties. Finally casein zymography revealed the presence of at least one extracellular protease with a molecular mass of about 50 kDa. In conclusion, the present study contributes to a better insight into bioactive compounds produced by dairy yeasts and shows the feasibility of D. hansenii strains to produce antihypertensive casein-derived peptides.This work was supported by grants AGL2010-21009 and AGL2011-24643 from ‘Ministerio de Educación y Ciencia – FEDER’, Consolider Ingenio 2010, Fun-C-Food, CSD2007-00063 and RETICS INVICTUS RD12/0014/0004 from ‘Instituto de Salud Carlos III’. A. García-Tejedor and L. Sánchez-Rivera are recipients of predoctoral fellowships from ‘Ministerio de Educación y Ciencia’ (BES-2011-044424) and CSIC (JAE-PreDoc), respectively.Peer reviewe

Cascaded H-bridge multilevel converter multistring topology for large scale photovoltaic systems

Large scale grid connected photovoltaic (PV) energy conversion systems have reached the megawatt level. This imposes new challenges on existing grid interface converter topologies and opens new opportunities to be explored. In this paper a new medium voltage multilevel-multistring configuration is introduced based on a three-phase cascaded H-bridge (CHB) converter and multiple string dc-dc converters. The proposed configuration enables a large increase of the total capacity of the PV system, while improving power quality and efficiency. The converter structure is very flexible and modular since it decouples the grid converter from the PV string converter, which allows to accomplish independent control goals. The main challenge of the proposed configuration is to handle the inherent power imbalances that occur not only between the different cells of one phase of the converter but also between the three phases. The control strategy to deal with these imbalances is also introduced in this paper. Simulation results of a 7-level CHB for a multistring PV system are presented to validate the proposed topology and control method

Novel Antihypertensive Lactoferrin-Derived Peptides Produced by Kluyveromyces marxianus: Gastrointestinal Stability Profile and In Vivo Angiotensin I-Converting Enzyme (ACE) Inhibition

Novel antihypertensive peptides released by Kluyveromyces marxianus from bovine lactoferrin (LF) have been identified. K. marxianus LF permeate was fractionated by semipreparative high performance liquid chromatography and 35 peptides contained in the angiotensin I-converting enzyme (ACE)-inhibitory fractions were identified by using an ion trap mass spectrometer. On the basis of peptide abundance and common structural features, six peptides were chemically synthesized. Four of them (DPYKLRP, PYKLRP, YKLRP, and GILRP) exerted in vitro inhibitory effects on ACE activity and effectively decreased systolic blood pressure after oral administration to spontaneously hypertensive rats (SHRs). Stability against gastrointestinal enzymes suggested that the sequence LRP could contribute to the in vivo effects of parental peptides. Finally, there were reductions in circulating ACE activity and angiotensin II level in SHRs after either DPYKLRP or LRP intake, thus confirming ACE inhibition as the in vivo mechanism for their antihypertensive effect.This work was supported by grant AGL2010–21009 from ‘Ministerio de Educación y Ciencia - FEDER’, Consolider Ingenio 2010, Fun-C-Food, CSD2007–00063 and RETICS INVICTUS RD12/0014/0004 from ‘Instituto de Salud Carlos III’. A.G.-T. is the recipient of a predoctoral fellowship from ‘Ministerio de Educación y Ciencia’ (BES-2011–044424).Peer reviewe

Desarrollo de habilidades y construcción conceptual : una secuencia sobre flotación en educación básica

Se presenta una secuencia para enseñar nociones sobre flotabilidad en un grupo de estudiantes de educación primaria. Su objetivo es brindar a los alumnos elementos que les ayuden a desarrollar nociones sobre el proceso de flotación, identificando algunas de las variables implicadas, como el volumen y la masa, a la par de promover el desarrollo de habilidades para el razonamiento científico, en este caso las que les permitan identificar y recolectar datos, elaborar predicciones, probar ideas, predicciones o explicaciones, identificar patrones y relaciones y sugerir posibles explicaciones. La secuencia, que forma parte de las actividades diseñadas para el Programa Adopte un Talento (PAUTA), ha sido probada en 6 grupos de estudiantes y los resultados de la evaluación se encuentran en proceso de análisis

Psychometric properties and invariance of an English self-efficacy scale for university students in Peru

"Background: English is a global language used to communicate with members of the international community. Self-efficacy in learning English is an important factor that is influenced by perceived importance, interest, and beliefs about the ability to successfully perform tasks in English. Objective: The aim is to develop and validate a measurement instrument to assess English self-efficacy. Methods: A total of 453 students from different Peruvian universities participated, with ages ranging from 18 to 60 years (M = 23; SD = 6.18). Statistical techniques for latent variables were used and recommendations for educational and psychological tests were followed in its construction. The sample was divided into two groups to perform exploratory factor analysis (EFA) and confirmatory factor analysis (CFA). Results: The English Self-Efficacy Scale (ESS-P) is representative and relevant in terms of its item content (Aiken’s V > 0.70). Its internal structure is organized into three first order factors and a second order factor that are consistent with the theoretical proposal and was confirmed through CFA with excellent goodnessof-fit indices (χ2  = 1184.9, gl = 626, CFI = 0.92, TLI = 0.92, RMSEA = 0.06 y SRMR = 0.04). It also has adequate internal consistency in its three factors (Reading α/ω = 0.96), Oral Communication (α/ω = 0.95), and Writing (α/ω = 0.97) and the whole scale (α/ω = 0.98), is invariant with respect to sex, and has a conceptual relationship with variables such as academic self-efficacy and exam anxiety. Conclusion: The ESS-P is a measurement instrument with evidence of validity, factorial invariance, and good reliability of its scores. Therefore, it can be used in future studies in the academic contex

Sistema de enfoque basado en dos espejos elípticos y un espejo plano rotatorio para un radar a 300 GHz

A focusing system for a 300 GHz radar with two target distances (5m and 10m) is proposed, having 1cm resolution in both cases. The focusing system is based on a gaussian telescope scheme and it has been designed using gaussian beam quasi-optical propagation theory with a homemade Matlab analysis tool. It has been translated into a real focusing system based on two elliptical mirrors and a plane mirror in order to have scanning capabilities and validated using the commercial antenna software GRAS

Management of Parkinson's disease and other movement disorders in women of childbearing age: Part 2

Introducción Muchas enfermedades que cursan con trastornos del movimiento hipercinético comienzan o afectan a mujeres en edad fértil. Es importante conocer los riesgos que tienen las mujeres con estas enfermedades durante el embarazo, así como los posibles efectos de los tratamientos sobre el feto. Objetivos Definir las características clínicas y los factores que condicionan la vida de la mujer en edad fértil con distonía, corea, síndrome de Tourette, temblor y síndrome de piernas inquietas. Definir una guía de actuación y manejo del embarazo y lactancia en las pacientes con esta enfermedad. Desarrollo Este documento de consenso se ha realizado mediante una búsqueda bibliográfica exhaustiva y discusión de los contenidos llevadas a cabo por un Grupo de Expertos en Trastornos del Movimiento de la Sociedad Española de Neurología (SEN). Conclusiones En todas las mujeres que padecen o comienzan con trastornos del movimiento hipercinéticos se debe valorar el riesgo-beneficio de los tratamientos, reducir al máximo la dosis eficaz o administrarlo de forma puntual en los casos en que sea posible. En aquellas enfermedades de causa hereditaria es importante un consejo genético para las familias. Es importante reconocer los trastornos del movimiento desencadenados durante el embarazo como determinadas coreas y síndrome de piernas inquietas.Introduction Many diseases associated with hyperkinetic movement disorders manifest in women of childbearing age. It is important to understand the risks of these diseases during pregnancy, and the potential risks of treatment for the fetus. Objectives This study aims to define the clinical characteristics and the factors affecting the lives of women of childbearing age with dystonia, chorea, Tourette syndrome, tremor, and restless legs syndrome, and to establish guidelines for management of pregnancy and breastfeeding in these patients. Results This consensus document was developed through an exhaustive literature search and a discussion of the content by a group of movement disorder experts from the Spanish Society of Neurology. Conclusions We must evaluate the risks and benefits of treatment in all women with hyperkinetic movement disorders, whether pre-existing or with onset during pregnancy, and aim to reduce effective doses as much as possible or to administer drugs only when necessary. In hereditary diseases, families should be offered genetic counselling. It is important to recognise movement disorders triggered during pregnancy, such as certain types of chorea and restless legs syndrome

Equity, barriers and cancer disparities: study of the Spanish Society of Medical Oncology on the access to oncologic drugs in the Spanish Regions

[Purpose] The Spanish Society of Medical Oncology (SEOM) has conducted a study on the access to oncologic drugs across the 17 Spanish Regions with the aim of identifying potential heterogeneities and making proposals for eliminating the barriers identified at the different levels.[Methods] An Expert Panel made up of medical oncologists designed a survey on certain indications approved for 11 drugs in the approach of breast cancer, melanoma, lung cancer, prostate cancer and support treatment. This survey was sent to 144 National Health System (NHS) hospitals. [Results] 77 hospitals answered the survey. The information modules analysed were: scope of the Commission that establishes binding decisions related to drug access; conditions, stages and periods of drug application, approval and administration processes; barriers to accessing drugs. [Conclusions] The study shows variability in drug access. The SEOM makes proposals addressed to reducing the differences identified and homogenizing drug access conditions.This study was funded by SEOM

Main properties of Al2O3 thin films deposited by magnetron sputtering of an Al2O3 ceramic target at different radio-frequency power and argon pressure and their passivation effect on p-type c-Si wafers

In this work, 50-nm thick Al2O3 thin films were deposited at room temperature by magnetron sputtering from an Al2O3 ceramic target at different RF power and argon pressure values. The sputtering technique could be preferred to conventional atomic layer deposition for an industrial application, owing to its simplicity, availability, and higher deposition rate. The resulting thin films were characterized by UV/Vis/NIR spectroscopy, X-ray diffraction, and X-ray photoelectron spectroscopy. The deposited Al2O3 material was always highly transparent and amorphous in nature. It was found that the O/Al ratio is higher when the Al2O3 layer is deposited at lower RF power or higher argon pressure. Also, some argon incorporation into the films was observed at low deposition pressure. On the other hand, the performance of the previously characterized Al2O3 thin films in the passivation of 2.25-Ωcm p-type float zone c-Si wafer surfaces was evaluated by the quasi-steady-state photoconductance technique. The best effective carrier lifetime value at one-sun illumination, 0.34 ms (corresponding to a surface recombination velocity of 41 cm/s), was obtained with the 50-nm Al2O3 deposited at the higher argon pressure studied, 0.67 Pa (5.0 mTorr), with the lowest RF power studied, 150 W (corresponding to a power density of 3.3 W/cm2), and after an annealing process, in this case at 350ºC for 20 min with forming gas. It was assumed that the reduction of the surface passivation quality at higher RF power or lower argon pressure is a consequence of an increased surface damage, and, probably, to a decrease of the O/Al ratio of the Al2O3 passivation material. These assumptions were confirmed with the obtainment of a lifetime of 0.73 ms (a surface recombination velocity equal to 19 cm/s) with a simple experiment with Al2O3 deposited with progressively varied sputtering conditions started from minimal silicon surface damage conditions: 50 W (corresponding to a power density of 1.1 W/cm2) and 6.67 Pa (50 mTorr). Finally, comments about further improvement of the effective lifetime (up to 1.25 ms, corresponding to a surface recombination velocity of 11 cm/s) with preliminary experiments about the incorporation of an intrinsic hydrogenated amorphous silicon interlayer are included

Depression, professional self-efficacy, and job performance as predictors of life satisfaction: the mediating role of work engagement in nurses

BackgroundThe life satisfaction and job performance of nursing professionals are affected by a multitude of factors, including work engagement, self-efficacy, and depression. The Job Demands-Resources (JD-R) model provides a theoretical framework to explore these relationships.ObjectiveOur study aimed to analyze the primary goal of this research, which is to examine the mediating role of work engagement in the relationship between depression, professional self-efficacy, job performance, and their impact on life satisfaction in nurses, using the JD-R theory as a guide.MethodsThis cross-sectional study involved 579 participants aged between 21 to 57 years (M = 39, SD = 9.95). Mediation analysis was used to examine the influence of depression, self-efficacy, and job performance on work engagement, and in turn, its effect on life satisfaction.ResultsFindings indicated that work engagement plays a crucial mediating role between depression, self-efficacy, job performance, and life satisfaction. Interventions to increase work engagement could assist nurses in better managing depression and improving their performance and life satisfaction.ConclusionsOur study highlights the need for workplace policies and strategies that foster work engagement and self-efficacy among nurses while effectively managing job demands to prevent depression. Moreover, these findings underscore the importance of the JD-R theory to understand and improve nurses' job satisfaction and performance, and suggest areas for future research, including exploring other potential factors and applying these findings across different contexts and cultures