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.

Bistable self-assembly in homogeneous colloidal systems for flexible modular architectures.

This paper presents a homogeneous system of magnetic colloidal particles that self-assembles via two structural patterns of different symmetry. Based on a qualitative comparison between a real magnetic particles system, analytical calculations and molecular dynamics simulations, it is shown that bistability can be achieved by a proper tailoring of an anisotropic magnetization distribution inside the particles. The presented bistability opens new possibilities to form two-dimensionally extended and flexible structures where the connectivity between the particles can be changed in vivo.

Radically rethinking agriculture for the 21st century.

Population growth, arable land and fresh water limits, and climate change have profound implications for the ability of agriculture to meet this century's demands for food, feed, fiber, and fuel while reducing the environmental impact of their production. Success depends on the acceptance and use of contemporary molecular techniques, as well as the increasing development of farming systems that use saline water and integrate nutrient flows.

Influencia del clima motivacional creado por el entrenador en el compromiso deportivo en jóvenes jugadores de baloncesto / No disponible

Uno de los objetivos en el deporte de base es conseguir una práctica divertida y duradera, y la figura del entrenador se antoja fundamental para conseguir un alto compromiso deportivo (García Calvo, Leo, Martín y Sánchez, 2008). Diversas investigaciones centradas en las percepciones de un entorno que implica a la tarea por parte del entrenador proporciona feedback, instrucciones positivas y apoyo social ayuda a arraigar una práctica deportiva continua (Smith, Fry, Ethington, y Li, 2005) y una menor tendencia a dejar el deporte. Por el contrario, los trabajos con entornos de ego creado por el entrenador proporciona menos soporte social y más feedback orientado al castigo (Smith et al., 2005), lo que conlleva a la retirada del deporte (Cervelló, Escartí, y Guzman, 2007). Por tanto, el principal objetivo de esta investigación es analizar la relación entre el compromiso deportivo y el clima motivacional que los jugadores perciben de los entrenadores (AU)

Relación de los componentes multidimensionales de la cohesión con el rendimiento en equipos de baloncesto / No disponible

En la relación de la cohesión y el rendimiento, los primeros resultados fueron poco concluyentes y poco constantes puesto que diversas investigaciones confirmaban tanto relaciones negativas como relaciones positivas. Para tratar de aclarar esta cuestión se han desarrollado diversos trabajos, destacando los metaanálisis de Mullen y Copper (1994), de Beal, Cohen, Burke y McLendon (2003) y de Carron, Colman, Wheeler y Stevens (2002) en los que se llega a la conclusión de que la relación entre cohesión y rendimiento es positiva, aunque poco significativa, centrándose principalmente en el constructo tarea de la cohesión. Por tanto, el principal objetivo de este estudio es analizar las relaciones existentes entre la cohesión de grupo y las expectativas de éxito y el rendimiento (AU)

Calidad en la administración de medicamentos intravenosos y su efecto en la seguridad del paciente / Quality in the administration of intravenous drugs and its effect on patient safety

El propósito de este estudio es evaluar la calidad en la administración de medicamentos por vía intravenosa que proporciona el profesional de enfermería a través de la aplicación de un instrumento que mide el índice de eficiencia, lo que permitirá determinar las fallas o casi-fallas e implementar estrategias de mejora, pero también identificar sus fortalezas para reforzarlas. Además los resultados, permiten valorar el impacto en la seguridad del paciente y determinar los factores con mayor peso para la ocurrencia de eventos adversos relacionados con la medicación. Es un estudio de tipo descriptivo, transversal, correlacional. La unidad de análisis son los procedimientos de administración de medicamentos intravenosos, que las enfermeras realizaron a los pacientes hospitalizados en los servicios de medicina interna, cardiología, neurología y gastroenterología de un Hospital Pediátrico de alta especialidad (n= 114), con el objeto de conocer el nivel de eficiencia y su relación con las variables intervinientes. Los resultados obtenidos nos permitieron identificar que el índice de eficiencia general es de 85% y al compararlo con respecto al día de observación es estadísticamente significativo para el fin de semana.

The purpose of this study was to assess the quality of the intravenous drug management provided by nursing professionals. We used a specific instrument to measure the efficiency of this process. These estimates will hopefully allow us determine the impact of related factors and thus identify problems and establish improvement strategies. This was a basic descriptive, cross-sectional and correlational study. The sample was formed out of 114 patients hos pitalized in the internal medicine, cardiology, neurology, and gastroentherology units of a high specialty Pediatric Hospital. The results suggest that it is possible to estimate a related index of efficiency close to 85%. We considered these findings as statistically significant.

Análisis de las bases teóricas del modelo de sistemas de Betty Neuman / Analysis of the theoretical bases model systems Betty Neuman

Este análisis realizado por los estudiantes del Programa de Maestría en Enfermería tiene como propósito: Explorar los elementos teóricos que surgen en el Modelo de Sistemas de Neuman, para contextuar los conceptos que subyacen de la propuesta en cuestión. Inicialmente se abordan antecedentes de Betty Neuman, posteriormente se plasman las áreas disciplinares en las que se basa (psicológica, filosófica y biológica), y se finaliza con la inferencia de algunos conceptos con los que la autora constituye su Modelo. Dentro del área Psicológica se encuentra la Teoría de Gestalt, del Estrés y la Situación en Crisis, en la Filosófica se ubica la Concepción de la Naturaleza Humana y la Visión Cosmogénica y en la Biológica se encuentra la Teoría de Sistemas. Esta última junto con la del Estrés y de Gestalt conforman gran parte del modelo donde la persona es el eje central del cuidado. Conclusión: El modelo por su estructura psicológica, filosófica y biológica sustentan la posibilidad de brindar un cuidado de enfermería integral. Este análisis ofrece al alumno de posgrado profundizar en las raíces teóricas permitiéndole reflexionar sobre el conocimiento enfermero y la práctica.

This analysis made by the students of the Program of Masters in Nursing has like intention: To explore the theoretical elements that arise inthe Model of Systems of Neuman, to contextuar the concepts that underlaying of the proposal at issue. Initially antecedents of Betty Neuman are approached, later the areas are shaped you will discipline on which it is based (psychological, philosophical and biological), and it is finalized with the inference of some concepts with which the author constitutes her Model. Within the Psychological area is the Theory of Gestalt, of Stress and the Situation in Crisis, in the Philosophical one is located the Conception of the Human Nature and the Cosmogenica Vision and in the Biological one is the Theory of Systems. This last along with the one of Stress and Gestalt they conform great part of the model where the person is the central axis of the care. Conclusion: The model by their psychological, philosophical and biological structure sustains the possibility of offering a care of integral nursing. This analysis offers to the posgrado student of deepening in the theoretical roots allowing him to reflect on the knowledge nurse and the practice.

Infectious diseases in Mazzaella laminarioides (Rhodophyta): estimating the effect of infections on host reproductive potential.

Very little is known about the potential effects of endophytic infections on the host in algae, especially in terms of fitness. In this study, we report a first attempt at quantifying the effects of the endophytes Endophyton ramosum (Chlorophyta) and Pleurocapsa sp. (Cyanophyta) on the reproductive potential of their host Mazzaella laminarioides (Rhodophyta). Density of reproductive structures and spore germination rates was compared between infected and non-infected fronds. It was found that differences in density of reproductive structures between infected and non-infected fronds were not significant, which suggests that the level of maturity of the host is unaltered by the endophytes. On the other hand, carpospore germination rates significantly decreased when produced by fronds infected by the cyanobacterium Pleurocapsa sp. Thus, in the general context of host fitness, we discuss the fact that only some of the components of the reproductive output of M. laminarioides are negatively affected by the endophytes.

Calcium and vitamin D status of pregnant teenagers in Maiduguri, Nigeria.

This study investigates parameters related to calcium and bone metabolism by determining the concentrations of total calcium, 25-hydroxyvitamin D, 1,25-dihydroxyvitamin D, parathyroid hormone, and phosphorous in young pregnant women. The patient population was 30 pregnant Nigerian teenage women grouped by trimester (10 per group), 10 women immediately following delivery, and 21 healthy age-matched controls. On the basis of serum prealbumin levels, the general nutrition of the pregnant women was found to be significantly below that of the more privileged and better-educated nonpregnant controls. The mean total calcium concentration in sera of the third-trimester women was 8.83 mg/dL, which was significantly below that of the controls (9.77 mg/dL) and the first-trimester group (9.30 mg/dL). Despite the 10% to 15% decline in the serum level of total calcium during pregnancy, the parathyroid hormone level decreased markedly from 0.60 to 0.61 ng/mL in the first and second trimesters to 0.41 ng/mL in the third trimester. Serum vitamin D and 1,25-dihydroxyvitamin D levels in the second and third trimesters were within the normal range. These data indicate that toward the end of gestation, pregnant teenagers in northern Nigeria appear to become calcium deficient and do not exhibit the expected increase in serum parathyroid hormone levels normally seen in pregnant women.

[Glucose metabolism in children undergoing extracorporeal circulation: its correlation with weight and the degree of hypothermia]. / Metabolismo de la glucosa en niños sometidos a circulación extracorpórea: correlación con peso y con grado de hipotermia.

INTRODUCTION: A prospective study has been carried out in 33 children with congenital heart disease, aged 5 days to 16 years, operated on with the aid of cardiopulmonary bypass (CPB), in order to evaluate intra and postoperative glycemia in relation to children's weight and intra-CPB perfusion temperature. MATERIAL AND METHODS: Plasmatic levels of glucose, lactate, insulin, C-peptide, growth hormone (GH) and cortisol were measured at five different times, from pre-CPB up to 18 hours post-CPB. Thirteen children weighing less than 10 kilograms (group I) were compared to 20 children weighing more than 10 kilograms (group II), and 15 children operated on with perfusion temperature below 27 degrees C (group A) were compared to 18 with perfusion temperature above 27 degrees C. RESULTS: All the cases showed intraoperative hyperglycemia. In relation to weight, evolution of glycemia was similar in both groups but anaerobic glycolysis was significantly higher in group I. In relation to temperature, glycemia, lactic acidemia intra- and post-CPB and serum C-peptide post-CPB were significantly higher in group A. Intraoperative insulin was decreased and GH serum levels were also higher in group I and A, but fell drastically post-CPB in all groups. CONCLUSIONS: Perioperative control of glycemia is important in children operated on with the aid of CPB. Control of lactic acidemia is also expedient. Carbohydrates metabolism and its hormonal regulation are more disturbed in infants and in children operated on with low perfusion temperature.

Control of Boophilus microplus populations in grazing cattle vaccinated with a recombinant Bm86 antigen preparation.

Current methods for the control of cattle tick Boophilus microplus infestations are not effective and the parasite remains a serious problem for the cattle industry in tropical and subtropical areas. Recently, we developed a vaccine against B. microplus employing a recombinant Bm86 (rBm86) antigen preparation (Gavac, Heber Biotec) and it was shown to induce a protective response in vaccinated animals under controlled conditions. Here we show that, under field conditions in grazing cattle, the vaccine is able to control B. microplus populations. Two parasite-free farms were employed for the study. In the first farm, animals were vaccinated with the recombinant vaccine, while, in the second, animals received a saline injection in adjuvant. After immunization, animals were artificially infected and the infestation rate was recorded. Over the 33 weeks of the experiment, the infestation rate was lower in the vaccinated group compared with the control group. At the end of the experiment it was necessary to use chemicals in the control farm after serious losses in production and animals.

[Synchronous carcinoma of the colon and the rectum (21 cases)]. / Carcinoma sincrónico de colon y recto (21 casos).

We present a retrospective study on 610 patients with colorectal cancer diagnosed over a 10 year period; 21 patients (3.4%) had synchronous multiple primary carcinomas. Age and clinical symptoms were similar to those with single carcinomas. In 57% of patients, the presence of synchronous neoplasms was diagnosed preoperatively by colonoscopy and/or barium enema, in 38% peroperatively and in 5% postoperatively. The more frequent localizations were rectum-sigmoid colon (24%) and descendent colon-sigmoid colon (19%). Three patients had 3 synchronous tumors, respectively. According to the Dukes classification, 80% of the patients had stage B or C. The five-year survival rate was 61%, similar to that for colon cancer in general. We emphasize the importance of preoperative identification of synchronous lesions; the whole colon should be investigated before surgery in order to ensure that no synchronous tumor has been missed or to change planned surgery.

[The short-, median- and long-term changes of mastocyte degranulation in the gastric submucosa of rats following truncal vagotomy]. / Modificaciones de la degranulación mastocitaria en la submucosa gástrica de la rata tras vagotomía troncular a corto, medio y largo plazo.

We study the effect of the truncal vagotomy on the degranulation activity of mast cell population in the submucosa of the rumen and fundus of the stomach of the rat after 7, 30, 60, 90 and 120 days of the surgical procedure. Also we analyze if the observed variations are connected with the existence or not of secretory activity in the studied area. The degranulation activity decreases in 7 days in the fundic secretory area with statistic significance, but not in the rumen. A significant increase of the degranulation is seen in both areas, after 90 days. We conclude that the effects of the vagotomy on mast cell degranulation in the submucosa of the stomach of rats depend on the presence or not of secretory activity in the studied area and the length of time after the surgical procedure.

Characterization of muscarinic receptors of bovine adrenal chromaffin cells: binding, secretion and anti-microtubule drug effects.

1. Binding of [3H]QNB to adrenal membranes is saturable, specific and to a single class of receptors. 2. Tubulozole, and not other microtubule drugs, inhibits [3H]QNB binding. 3. Pretreating cultured chromaffin cells with oxotremorine, a muscarinic receptor agonist, has no effect on either basal, nicotine (10 microM) or K(+)-stimulated catecholamine release and failed to enhance secretion of submaximal concentrations of nicotine (3-5 microM). 4. These results confirm that binding of [3H]QNB is associated with muscarinic receptors on bovine adrenal medullary tissue. 5. These studies also demonstrate that although bovine adrenal chromaffin cells possess muscarinic receptors, these receptors do not appear to be coupled to secretory processes.

[Complete atrioventricular canal and tetralogy of Fallot: surgical considerations]. / Canal atrioventricular completo y tetralogía de Fallot: consideraciones quirúrgicas.

Nine patients with complete atrioventricular canal and tetralogy of Fallot underwent intracardiac repair of both anomalies between 1982 and 1989. The ages of the patients ranged from 6 months to 7 years. Six of the 9 had one or more previous systemic-pulmonary artery shunts. Two-dimensional echocardiography showed diagnostic characteristics of both malformations in all patients. The diagnosis was confirmed by cardiac catheterization and cineangiography. The ventricular septal defect was repaired by a combined right atrial and ventricular approach in every patient. Outflow tract reconstruction was performed with the use of a transannular patch (4), infundibular patch (4), and a valved conduit (1). There were no hospital deaths. Meningitis was responsible for the death of a patient 2 years after repair. We recommend early palliation, complete repair in those older than 4 or 5 years, surgical technique depending on the anatomical findings, combined atrial and ventricular approach, 2 separate patches to close the ventricular septal defect in required cases, adjusted correction of the right ventricular outflow tract, and careful postoperative care.

Complete atrioventricular canal and tetralogy of Fallot: surgical management.

Between 1982 and 1989, nine patients with complete atrioventricular (AV) canal and tetralogy of Fallot underwent successful repair of both anomalies. Seven patients had Down's syndrome. One or more previous palliative shunts had been used in six patients. Associated cardiovascular lesions included persistent left superior vena cava (two patients), patent ductus arteriosus with marked stenosis of the left pulmonary artery (one patient). The diagnosis was confirmed by cardiac catheterization and cineangiography. Closure of the ventricular septal defect was performed through a combined right atrial and ventricular approach in each patient. The right ventricular outflow obstruction was relieved with the use of a transannular patch (4), right ventricular infundibular patch (4) or a valved external conduit (1). There were no hospital deaths. One patient died as a result of meningitis 2 years after repair. Progressive left AV valve incompetence developed in one patient requiring valve replacement. A single atrial approach may not provide the best exposure of the subaortic end of the defect. In this regard, we recommend an additional right ventriculotomy in order to ensure safe closure of the septal defect. Although an adequately shaped isolated patch could be sufficient to close the anterior VSD, we favour a separate patch to minimize the possibility of producing subaortic obstruction. A further method to avoid this subaortic stenosis consists of dividing the common anterior leaflet to the right towards the lateral extent of the infundibular septum.

[Surgery of congenital cardiopathies without previous catheterization. Preoperative evaluation and surgical indication using bidimensional echocardiography and Doppler]. / Cirugía de las cardiopatías congénitas sin cateterismo previo. Valoración preoperatoria e indicación quirúrgica por ecocardiografía bidimensional y Doppler.

With the non-invasive devices available nowadays, many congenital heart diseases may be diagnosed with a definition comparable and even perhaps superior to catheterization and angiography. According to this issue, from January 1983 to December 1987, 239 children underwent operations for palliation or correction of different cardiopathies based on an echo-Doppler assessment without prior catheterization. Preoperative echo-Doppler diagnoses had an adequate correlation with the surgical findings in 234 cases (97.9 percent), so there was no correlation in 5 cases. In general, we consider that echo-Doppler provides a complete and definitive diagnosis in most cases, thus eliminating the need for further invasive procedures, although we still have to rely on catheterization to obtain the necessary information or reassurance in some cases. Progressive increase of reliance in echo-Doppler techniques by the surgeon and self confidence of the cardiologist in his accurate state of the art will considerably increase the performance of cardiac operations without prior catheterization in the future. At present, this is our current policy, as day after day, we are increasing the diagnoses in which we consider unnecessary the catheterization to indicate surgery.

[Atrioventricular septal defect with associated tetralogy of Fallot. Clinico-morphological aspects and surgical considerations]. / Defecto del septo atrioventricular con tetralogía de Fallot asociada. Aspectos clinicomorfológicos y consideraciones quirúrgicas.

In this work the clinical features, diagnostic methods, surgical procedures and postoperative follow-up are reviewed in 19 cases of atrioventricular septal defect with associated tetralogy of Fallot. The clinical situation was always related to the degree of pulmonary ischemia, that pointed out the urgency and need for a palliative surgical procedure before corrective surgery. There was no data in the ECG for the differential diagnosis of isolated forms of atrioventricular septal defect. In 50% of the cases the cardio-thoracic index was increased by right atrial enlargement. The diagnosis of the malformation was made in every case by means of 2D echocardiography. In 16 cases palliative surgery was done (aortic-pulmonary shunts), with one death (6.2%) due to facts unrelated to the technique. Of the 6 cases with corrective surgery (5 cases with previous shunts), one needed a mitral valve replacement (St Jude prosthesis). There was no mortality in this group and the functional status in the long-term follow-up was: 3 cases were in the functional class I and 3 cases in class II. The overall mortality for all surgical procedures carried out was 4.3%. In conclusion, we consider the use of the corrective surgery adequate to the clinical stability of the patients with atrioventricular septal defect with associated Fallot's tetralogy.

[Appendicular mucocele. Review of the literature and presentation of 8 cases]. / "Mucocele apendicular". Revisión de la literatura y aportación de ocho casos.

We reviewed the term mucocele, which some authors think should be abolished, although we do not share this opinion. We think it should be understood as no more than a descriptive term indicating dilation of the vermiform appendix by intraluminal accumulation of mucoid material, with no regard for its diverse etiology, which is the origin of the variety of terms and classifications of this condition encountered in the literature. We describe the clinical variety of this entity, emphasizing the exceptionality of its preoperative diagnosis before the introduction of modern techniques (US and CAT), which have permitted a growing number of exact diagnoses. The most appropriate technique for surgical treatment is discussed. The cases recently published in Spain are reviewed and we contribute 8 cases of our own.