Effective index model as a reliable tool for the design of nanostructured thin-film solar cells.

Nanostructured anti-reflection coatings (ARC) are used to reduce the reflectivity of the front surface of solar cells. Computational electromagnetism helps to evaluate the spectral reflectivity of of this type of ARC using several approaches. They typically require large computational resources both in time and hardware elements (memory allocation, speed of processors, etc.). Long computational times may jeopardize optimization processes based on the iterative evaluation of a given merit function that depends on several parameters. Then, simplified analytic methods can speed up this evaluation with moderate computational resources. In this contribution we adapt an Effective Index Model (EIM) to the case of the design of an ARC made with nanoparticles (NP) embedded in a medium at the front surface of a thin-film silicon solar cell. Our approach modifies the discrete dipole approximation method to adapt it to the geometric and material properties of the NPs. The results obtained from the analytic method are compared with those evaluated through a Finite Element Method (FEM) for several cases involving variations in the size and geometry of the NP arrangement, obtaining reflectances that differ less than 10[Formula: see text] for the worst case analyzed but bieng about 100 times faster than the FEM.

Upconverting Carbon Nanodots from Ethylenediaminetetraacetic Acid (EDTA) as Near-Infrared Activated Phototheranostic Agents.

This work describes the synthesis of nitrogen-doped carbon nanodots (CNDs) synthesized from ethylenediaminetetraacetic acid (EDTA) as a precursor and their application as luminescent agents with a dual-mode theranostic role as near-infrared (NIR) triggered imaging and photodynamic therapy agents. Interestingly, these fluorescent CNDs are more rapidly and selectively internalized by tumor cells and exhibit very limited cytotoxicity until remotely activated with a NIR illumination source. These CNDs are excellent candidates for phototheranostic purposes, for example, simultaneous imaging and therapy can be carried out on cancer cells by using their luminescent properties and the in situ generation of reactive oxidative species (ROS) upon excitation in the NIR range. In the presence of CNDs, NIR remote activation induces the in vitro killing of U251MG cells. Through the use of flow imaging cytometry, we have been able to successfully map and quantify the different types of cell deaths induced by the presence of intracellular superoxide anions (. O2 - ) and hydrogen peroxide (H2 O2 ) ROS generated in situ upon NIR irradiation.

Hypoxia and iron requirements are the main drivers in transcriptional adaptation of Kluyveromyces lactis during wine aerobic fermentation.

The respiratory metabolism of yeast species alternative to Saccharomyces cerevisiae has been explored in recent years as a tool to reduce ethanol content in grape wine. The efficacy of this strategy has been previously proven for mixed cultures of non-Saccharomyces and S. cerevisiae strains. In this work, we perform a transcriptomic analysis of the Crabtree-negative yeast Kluyveromyces lactis under tightly controlled growth conditions in order to better understand physiology of non-Saccharomyces yeasts during the fermentation of grape must under aerated conditions. Transcriptional changes in K. lactis are mainly driven by oxygen limitation, iron requirement, and oxidative stress. Oxidative stress appears as a consequence of the hypoxic conditions achieved by K. lactis once oxygen supply is no longer sufficient to sustain fully respiratory metabolism. This species copes with low oxygen and iron availability by repressing iron consuming pathways and activating iron transport mechanisms. Most of the physiological and transcriptomic features of K. lactis in aerobic wine fermentation are not shared with the Crabtree-positive yeast S. cerevisiae.

Maculopatía por puntero láser. ¿Un nuevo problema de salud pública? / Laser pointer maculopathy. A new public health problem?

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Oral butyrate reduces oxidative stress in atherosclerotic lesion sites by a mechanism involving NADPH oxidase down-regulation in endothelial cells.

Butyrate is a 4-carbon fatty acid that has antiinflammatory and antioxidative properties. It has been demonstrated that butyrate is able to reduce atherosclerotic development in animal models by reducing inflammatory factors. However, the contribution of its antioxidative effects of butyrate on atherogenesis has not yet been studied. We investigated the influence of butyrate on oxidative status, reactive oxygen species (ROS) release and oxidative enzymes (NADPH oxidase and iNOS) in atherosclerotic lesions of ApoE(-/-) mice and in oxLDL-stimulated peritoneal macrophages and endothelial cells (EA.hy926). The lesion area in aorta was reduced while in the aortic valve, although lesion area was unaltered, superoxide production and protein nitrosylation were reduced in butyrate-supplemented mice. Peritoneal macrophages from the butyrate group presented a lower free radical release after zymosan stimulus. When endothelial cells were pretreated with butyrate before oxLDL stimulus, the CCL-2 and superoxide ion productions and NADPH oxidase subunit p22phox were reduced. In macrophage cultures, in addition to a reduction in ROS release, nitric oxide and iNOS expression were down-regulated. The data suggest that one mechanism related to the effect of butyrate on atherosclerotic development is the reduction of oxidative stress in the lesion site. The reduction of oxidative stress related to NADPH oxidase and iNOS expression levels associated to butyrate supplementation attenuates endothelium dysfunction and macrophage migration and activation in the lesion site.

Non-conventional Yeast Species for Lowering Ethanol Content of Wines.

Rising sugar content in grape must, and the concomitant increase in alcohol levels in wine, are some of the main challenges affecting the winemaking industry nowadays. Among the several alternative solutions currently under study, the use of non-conventional yeasts during fermentation holds good promise for contributing to relieve this problem. Non-Saccharomyces wine yeast species comprise a high number or species, so encompassing a wider physiological diversity than Saccharomyces cerevisiae. Indeed, the current oenological interest of these microorganisms was initially triggered by their potential positive contribution to the sensorial complexity of quality wines, through the production of aroma and other sensory-active compounds. This diversity also involves ethanol yield on sugar, one of the most invariant metabolic traits of S. cerevisiae. This review gathers recent research on non-Saccharomyces yeasts, aiming to produce wines with lower alcohol content than those from pure Saccharomyces starters. Critical aspects discussed include the selection of suitable yeast strains (considering there is a noticeable intra-species diversity for ethanol yield, as shown for other fermentation traits), identification of key environmental parameters influencing ethanol yields (including the use of controlled oxygenation conditions), and managing mixed fermentations, by either the sequential or simultaneous inoculation of S. cerevisiae and non-Saccharomyces starter cultures. The feasibility, at the industrial level, of using non-Saccharomyces yeasts for reducing alcohol levels in wine will require an improved understanding of the metabolism of these alternative yeast species, as well as of the interactions between different yeast starters during the fermentation of grape must.

L-arginine pretreatment reduces intestinal mucositis as induced by 5-FU in mice.

Beneficial effects of L-arginine on immune responses and bowel function have been reported. Mucositis is a side effect of chemotherapy treatment that affects approximately 40% of patients. This complication is characterized by inflammation that affects the gastrointestinal tract, increasing permeability and causing abdominal pain, nausea, vomiting, and diarrhea, which worsen the patient's nutritional status and increases morbimortality. The aim of this study was to evaluate the effect of pretreating with 2% L-arginine supplementation in water on mucositis as induced by 5-fluorouracil (5-FU; a single dose of 200 mg/kg body weight) in Swiss male mice. The effect of L-arginine on weight, intestinal permeability, morphology, and the histopathological score of the small intestine (from 0 to 12), oxidative stress, myeloperoxidase (MPO), and N-acetylglucosaminidase (NAG) activities were evaluated. Intestinal length improvement was observed, in addition to the partial recovery of the mucosal architecture. L-arginine attenuated the histopathological score and MPO activity. There was also an improvement in intestinal permeability, despite weight loss after 5-FU administration. In conclusion, L-arginine can positively impact intestinal mucositis by promoting partial mucosal recovery, reducing inflammation and improving intestinal permeability.

Antioxidative and immunomodulatory effects of tributyrin supplementation on experimental colitis.

Tributyrin (TBT) is a TAG composed of three butyric acids that has beneficial effects on ulcerative colitis due to its trophic, anti-inflammatory, pro-apoptotic and anti-carcinogenic properties. The goal of the present study was to evaluate the efficacy and mechanisms of action of TBT supplementation in the prevention of mucosal damage in experimental colitis. Mice received either a control diet or a TBT-supplemented diet for 15 d. Colitis was induced by dextran sodium sulphate administration during the last 7 d. Mucosal damage and the activation of immune cells and cytokines were determined by histological score, flow cytometry and ELISA. Leucocyte rolling and adhesion were assessed by intravital microscopy. Oxidative stress was determined by monitoring hydroperoxide concentration and evaluating superoxide dismutase (SOD) and catalase activities. Intestinal permeability was analysed using diethylenetriaminepentaacetate acid (99mTcDTPA). Compared with the colitis group, the animals in the colitis+TBT group had reduced mucosal damage and neutrophil and eosinophil mucosal infiltration, which were associated with a higher percentage of regulatory T cells (Treg) and higher levels of transforming growth factor ß and IL-10 in the lamina propria. The level of in vivo leucocyte adhesion in the colon microvasculature was reduced after TBT supplementation. A lower level of hydroperoxide and higher levels of SOD and catalase activities were associated with TBT supplementation. TBT-supplemented mice showed reduced intestinal permeability to the levels intermediate between the control and colitis groups. In conclusion, the present results show that TBT has positive effects on colonic restructuring in experimental colitis. Additionally, TBT supplementation changes the immune response by controlling inflammation and regulating the expression of anti-inflammatory cytokines and Treg.

Butyrate: implications for intestinal function.

PURPOSE OF REVIEW: Butyrate is physiologically produced by the microbial fermentation of dietary fibers and plays a plurifunctional role in intestinal cells. This review examines the recent findings regarding the role and mechanisms by which butyrate regulates intestinal metabolism and discusses how these findings could improve the treatment of several gastrointestinal disorders. RECENT FINDINGS: Butyrate is more than a primary nutrient that provides energy to colonocytes and acts as a cellular mediator in those cells through several mechanisms. One remarkable property of butyrate is its ability to inhibit histone deacetylases, which is associated with the direct effects of butyrate and results in gene regulation, immune modulation, cancer suppression, cell differentiation, intestinal barrier regulation, oxidative stress reduction, diarrhea control, visceral sensitivity and intestinal motility modulation. All of these actions make butyrate an important factor for the maintenance of gut health. SUMMARY: From studies published over 30 years, there is no doubt of the important role that butyrate plays in maintaining intestinal homeostasis. However, despite these effects, clinical studies are still required to validate the routine use of butyrate in clinical practice and, specifically, in the treatment of intestinal diseases.

Oral administration of sodium butyrate attenuates inflammation and mucosal lesion in experimental acute ulcerative colitis.

Butyrate is a four-carbon short-chain fatty acid that improves colonic trophism. Although several studies have shown the benefits of butyrate enemas in ulcerative colitis (UC), studies using the oral route are rare in the literature. In the present study, we evaluated the effect of butyrate intake in the immune response associated to UC. For that, mice were fed control or butyrate (0.5% sodium butyrate) diets for 14 days. Acute UC was induced by dextran sulphate sodium (DSS, 2.5%), replacing drinking water. The results showed that, in UC animals, oral butyrate significantly improved trophism and reduced leukocyte (eosinophil and neutrophil) infiltration in the colon mucosa and improved the inflammatory profile (activated macrophage, B and T lymphocytes) in cecal lymph nodes. In the small intestine, although mucosa histology was similar among groups, DSS treatment reduced duodenal transforming growth factor-ß, increased interleukin-10 concentrations and increased memory T lymphocytes and dendritic cells in Peyer's patches. Butyrate supplementation was able to revert these alterations. When cecal butyrate concentration was analyzed in cecal content, it was still higher in the healthy animals receiving butyrate than in the UC+butyrate and control groups. In conclusion, our results show that oral administration of sodium butyrate improves mucosa lesion and attenuates the inflammatory profile of intestinal mucosa, local draining lymph nodes and Peyer's patches of DSS-induced UC. Our results also highlight the potential use of butyrate supplements as adjuvant in UC treatment.

The combination of high-fat diet-induced obesity and chronic ulcerative colitis reciprocally exacerbates adipose tissue and colon inflammation.

BACKGROUND: This study evaluated the relationship between ulcerative colitis and obesity, which are both chronic diseases characterized by inflammation and increases in immune cells and pro-inflammatory cytokines. METHODS: Mice with chronic ulcerative colitis induced by 2 cycles of dextran sodium sulfate (DSS) in the first and fourth week of the experiment were fed a high-fat diet (HFD) to induce obesity by 8 weeks. The animals were divided into 4 \ groups (control, colitis, HFD and colitis + HFD). RESULTS: Obesity alone did not raise histopathology scores, but the combination of obesity and colitis worsened the scores in the colon compared to colitis group. Despite the reduction in weight gain, there was increased inflammatory infiltrate in both the colon and visceral adipose tissue of colitis + HFD mice due to increased infiltration of macrophages, neutrophils and lymphocytes. Intravital microscopy of VAT microvasculature showed an increase in leukocyte adhesion and rolling and overexpression of adhesion molecules compared to other groups. Moreover, circulating lymphocytes, monocytes and neutrophils in the spleen and cecal lymph nodes were increased in the colitis + HFD group. CONCLUSION: Our results demonstrated the relationship between ulcerative colitis and obesity as aggravating factors for each disease, with increased inflammation in the colon and adipose tissue and systemic alterations observed in the spleen, lymph nodes and bloodstream.

Use of Raman spectroscopy for the early detection of filaggrin-related atopic dermatitis.

BACKGROUND: Filaggrin (FLG) gene mutations, which result in complete or incomplete loss of proFLG/FLG peptides, have been reported as an important predisposing factor for atopic dermatitis (AD) and secondary atopic phenotypes such as atopic asthma. METHOD: The presence of the protein FLG in the skin was evaluated at birth on 12 infants using Raman spectroscopy; these 12 infants were monitored for 1 year to see whether they developed AD. Three different statistical analysis procedures, two of which involved principal component analysis (PCA), were performed on the Raman spectra in order to determine the FLG content. RESULTS: The infants who had a lower FLG content, determined using any of the three statistical analysis procedures proposed, were also the ones that clinically developed AD. CONCLUSION: The results suggest that Raman spectroscopy and statistical analysis such as PCA could be used as an early detection procedure for FLG -related AD and as a possible quantitative marker for FLG gene mutations.

Concordancia entre padres e hijos en la calidad de vida relacionada con la salud en niños con trastorno por déficit de atención con hiperactividad: estudio longitudinal / Parent-child agreement in the health related quality of life (HRQOL) of children with attention-deficit/hyperactivity disorder (ADHD): A longitudinal study

Objetivos: Evaluar la concordancia entre padres e hijos sobre los cambios producidos en la calidad de vida relacionada con la salud (CVRS) de niños tratados por trastorno por déficit de atención con hiperactividad (TDAH) durante un corto período de tiempo y comparar las puntuaciones con las normas de referencia de la población general. Métodos: Estudio prospectivo en niños de 6 a 12 años con TDAH. Los padres y sus hijos completaron la versión española del CHIP-CE (Child Health and Illness Profile-Child Edition ‘Perfil de salud infantil’) al iniciar el tratamiento y a las 8 semanas. Las puntuaciones del CHIP-CE de ambas visitas se compararon mediante el test de la t de Student para datos apareados, el tamaño del efecto (TE), los coeficientes de correlación intraclase (CCI) y los diagramas de dispersión. Las evaluaciones de padres e hijos se compararon con las puntuaciones del CHIP-CE de la muestra de referencia española. Resultados: En el análisis se incluyó a 31 niños y a sus padres. El mayor cambio entre la visita inicial y la visita de seguimiento se produjo en la dimensión de riesgos, tanto en los niños como en los padres (TE=0,24 y 0,49, respectivamente). El CCI presentó un intervalo de entre 0,44 (satisfacción) y 0,01 (riesgos). Las puntuaciones de los niños fueron similares a los valores de referencia poblacional. Todas las dimensiones de la versión de padres del CHIP-CE presentaron puntuaciones medias estandarizadas inferiores a los valores de referencia en la visita inicial y fueron próximas a los valores de referencia tras el tratamiento. Conclusiones: El presente estudio mostró poca concordancia entre padres e hijos y sugiere que se deberían recoger ambas perspectivas en futuros estudios del impacto y del tratamiento del TDAH (AU)

Objectives: To assess parent-child agreement on changes over a short-term period of time in the HRQOL of children treated for ADHD over a short period of time, and to compare child and parent ratings of children with ADHD with general population norms. Methods: Prospective study in children 6-12 years old with ADHD. Children and parents completed the Spanish versions of the Child Health and Illness Profile-Child Edition (CHIP-CE) before and after 8 weeks of treatment. CHIP-PE scores at both visits were compared using paired t tests and effect sizes (ES), intra-class correlation coefficients (ICC), and scatter plots. Child and parent ratings were compared with CHIP-CE scores for a general population sample. Results: Thirty-one children and parents were included in the analysis. The highest change between the first and the follow-up visit was on the Risk Avoidance domain both children and parents (effect size [ES]=0.24 and 0.40, respectively). The ICC ranged from 0.44 (Satisfaction) to 0.01 (Risk avoidance). Child self-ratings were close to general population values. All domains of the parent version presented standardized means below the reference values at the baseline visit and closer to the general population norm after treatment. Conclusions: This study found poor parent-child agreement and suggests that both ratings should be collected in future studies on the impact of ADHD and treatment effectiveness (AU)

[Parent-child agreement in the health related quality of life (HRQOL) of children with attention-deficit/hyperactivity disorder (ADHD): a longitudinal study]. / Concordancia entre padres e hijos en la calidad de vida relacionada con la salud en niños con trastorno por déficit de atención con hiperactividad: estudio longitudinal.

OBJECTIVES: To assess parent-child agreement on changes over a short-term period of time in the HRQOL of children treated for ADHD over a short period of time, and to compare child and parent ratings of children with ADHD with general population norms. METHODS: Prospective study in children 6-12 years old with ADHD. Children and parents completed the Spanish versions of the Child Health and Illness Profile-Child Edition (CHIP-CE) before and after 8 weeks of treatment. CHIP-PE scores at both visits were compared using paired t tests and effect sizes (ES), intra-class correlation coefficients (ICC), and scatter plots. Child and parent ratings were compared with CHIP-CE scores for a general population sample. RESULTS: Thirty-one children and parents were included in the analysis. The highest change between the first and the follow-up visit was on the Risk Avoidance domain both children and parents (effect size [ES]=0.24 and 0.40, respectively). The ICC ranged from 0.44 (Satisfaction) to 0.01 (Risk avoidance). Child self-ratings were close to general population values. All domains of the parent version presented standardized means below the reference values at the baseline visit and closer to the general population norm after treatment. CONCLUSIONS: This study found poor parent-child agreement and suggests that both ratings should be collected in future studies on the impact of ADHD and treatment effectiveness.

Stringhalt in Brazilian horses caused by Hypochaeris radicata.

Two outbreaks of Hypochaeris radicata-induced Australian stringhalt involving two farms and seven horses from southern Brazil are reported here. Subsequently, the disease was experimentally reproduced in a feeding trial with one colt fed H. radicata from the suspect paddocks. Fresh H. radicata was fed to the experimental animal for 50 days at an average daily dosage of 9.8 kg. Initially, the plant was collected from the paddock where the clinical disease occurred and was fed for 19 consecutive days producing mild clinical signs. However, on days 20-23 fresh plant was collected from a neighboring farm where the disease had not been reported and fed to the colt at which time the colt appeared to recover. Therefore, plant collections from the original suspect paddock resumed and feeding trials continued with clinical signs reoccurring by day 36, and increasing in intensity from days 43-50 after which plant administration was stopped. Within 15 days after ending the feeding trial with H. radicata, the colt appeared to have recovered. This experimental reproduction of stringhalt in a single colt fed H. radicata demonstrated that the two outbreaks of the disease resulted from this plant. Interestingly, the change in location for collection of plant material 19 days into the treatment, and the subsequent recovery of the colt, would suggest that plant material may differ in toxicity depending on location.

Aprendizaje basado en la solución de problemas en fisiología circulatoria: el caso o problema como nexo de unión para la integración curricular / Problem-based learning in cardiovascular physiology. The case as a link for curriculum integration

Antecedentes. El aprendizaje basado en la solución de problemas (ABSP) como filosofía tiene una amplia difusión mientras que su utilización como un método más en el currículo convencional/tradicional se ha ensayado escasamente. Objetivos. Valorar por parte de los estudiantes: a) el ABSP como un método dentro de un currículo convencional/tradicional, y b) el problema/caso como instrumento integrador, concurrente y secuencial, del currículo. Método y estrategias. Se ha utilizado un cuestionario basado en el de Ghosh y Dawka9 para valorar por parte de los estudiantes los objetivos planteados en el contexto de la enseñanza de la fisiología cardiovascular. Resultados. Los alumnos valoran el ABSP combinado juiciosamente con las clases teóricas como "muy útil" (valoración más alta) en la enseñanza de la fisiología cardiovascular y consideran al problema como un instrumento de integración en un porcentaje significativo. Conclusión. El ABSP puede ser el método clave para motivar a los estudiantes y conseguir una mejora en la calidad de los nuevos diseños y desarrollos curriculares (AU)

El profesor del siglo XXI: visión del alumnado / Professor of century XXI: opinion of the students

Este trabajo intenta definir las características o "estrellas" que debe tener un profesor que busque la excelencia desde la consideración del alumnado. Para ello se ha diseñado una encuesta que se pasó a los alumnos de primero, tercero y sexto cursos. Los resultados muestran que el profesor de excelencia o profesor del siglo XXI ha de ser: un comunicador aceptable, con sólidos conocimientos pedagógico-didácticos, actividad asistencial y excelentes cualidades humanas como sentido común, tolerancia y accesibilidad (AU)

Synechocystis strain PCC 6803 cya2, a prokaryotic gene that encodes a guanylyl cyclase.

Synechocystis strain PCC 6803 exhibits similar levels of cyclic AMP (cAMP) and cyclic GMP (cGMP). A thorough analysis of its genome showed that Cya2 (Sll0646) has all the sequence determinants required in terms of activity and purine specificity for being a guanylyl cyclase. Insertional mutagenesis of cya2 caused a marked reduction in cGMP content without altering the cAMP content. Thus, Cya2 represents the first example of a prokaryotic guanylyl cyclase.

Visual perception of the Moiré effect.

The perception of Moiré fringes is studied with two different tests for binocular and monocular conditions. The results are negative for binocular conditions, and positive for the monocular case when afterimages are used.