Fabrication and deposition of copper and copper oxide nanoparticles by laser ablation in open air

The proximity of the “post-antibiotic era”, where infections and minor injuries could be a cause of death, there are urges to seek an alternative for the cure of infectious diseases. Copper nanoparticles and their huge potential as a bactericidal agent could be a solution. In this work, Cu and Cu oxide nanoparticles were synthesized by laser ablation in open air and in argon atmosphere using 532 and 1064 nm radiation generated by nanosecond and picosecond Nd:YVO4 lasers, respectively, to be directly deposited onto Ti substrates. Size, morphology, composition and the crystalline structure of the produced nanoparticles have been studied by the means of field emission scanning electron microscopy (FESEM), high resolution transmission electron microscopy (HRTEM), the energy dispersive spectroscopy of X-rays (EDS), selected area electron diffraction (SAED) and X-ray diffraction (XRD). The UV-VIS absorbance of the thin layer of nanoparticles was also measured, and the antibacterial capacity of the obtained deposits tested against Staphylococcus aureus. The obtained deposits consisted of porous coatings composed of copper and copper oxide nanoparticles interconnected to form chain-like aggregates. The use of the argon atmosphere contributed to reduce significantly the formation of Cu oxide species. The synthesized and deposited nanoparticles exhibited an inhibitory effect upon S. aureus.Peer ReviewedPostprint (published version

Ab initio study of the influence of nanoscale doping inhomogeneities in the phase separated state of La1−x_{1-x}Cax_{x}MnO3_3

The chemical influence in the phase separation phenomenon that occurs in perovskite manganites is discussed by means of ab initio calculations. Supercells have been used to simulate a phase separated state, that occurs at Ca concentrations close to the localized to itinerant crossover. We have first considered a model with two types of magnetic ordering coexisting within the same compound. This is not stable. However, a non-isotropic distribution of chemical dopants is found to be the ground state. This leads to regions in the system with different effective concentrations, that would always accompany the magnetic phase separation at the same nanometric scale, with hole-rich regions being more ferromagnetic in character and hole-poor regions being in the antiferromagnetic region of the phase diagram, as long as the system is close to a phase crossover.Comment: 8 pages, 7 figures, 1 tabl

Comparative analysis of the serve in volleyball between the spanish championships 2005-2010

El objetivo fue analizar los cambios que ha experimentado el saque desde el Campeonato de España cadete masculino de 2005 al de 2010. Mediante la observación sistemática se analizaron 1594 acciones, en las cuales se midieron las siguientes variables: zona de origen, eficacia, tipo de saque, zona de recepción, función del receptor, dirección y temporalidad. Los resultados reflejaron que en los últimos años, el saque realizado por jugadores de categoría de formación ha sufrido modificaciones relevantes, tales como, mejora de la eficacia, incremento del empleo del saque en salto, y realización del saque con un carácter más táctico. Pese a la mayor aproximación del saque a los perfiles existentes en alto nivel, se recomienda que el saque de voleibol en categorías de formación se entrene en función de las características y nivel de los jugadores, evitando el mimetismo de lo que acontece en alto nivelThe aim of this research was to analyze the changes in the characteristics of the serve between the male Under-16 Spanish Championships that took place in 2005 and 2010. Through systematic observation 1594 actions were analyzed. The measured variables were: serve zone, effectiveness, serve type, reception zone, in-game role of the receptor, serve direction and timing. The results showed that in recent years, the serve performed by players at training stages has undergone significant changes, such as improved efficiency, increased use of jump serve, and execution of the serve with a more tactical role. Despite of the closest approach of the serve to the existing high level profiles, it is recommended to train the serve in volleyball training stages according to the characteristics and level of players, avoiding mimicry of what happens at a high levelEste trabajo ha sido realizado gracias al apoyo del Programa de Formación de Personal Investigador (FPI) de la Consejería de Empleo, Empresa e Innovación del Gobierno de Extremadura (España), y gracias al Ministerio de Ciencia e Innovación en el Plan Nacional de I+D+I 2008-2011 (ref. DEP2011-27503

A hybrid tgfu/se volleyball teaching unit for enhancing motivation in physical education: A mixed-method approach

Grounded in self-determination theory, this pre-experimental study analyzed the effects of a hybrid teaching games for understanding/sport education (TGfU/SE) volleyball teaching unit on students’ motivational outcomes, using a mixed-method approach. It also examined whether the intervention was equally effective for boys and girls. Participants were 53 secondary school students (Mage = 15.50, SDage = 0.57) who were taught through a hybrid TGfU/SE unit. The structure of this unit was designed according to the characteristics of SE model, while learning tasks were designed by using the pedagogical principles of TGfU model. Both self-reported validated questionnaires and focus groups were used before and after intervention to assess students’ motivational responses. After the hybrid TGfU/SE unit, both quantitative and qualitative findings showed improvements in students’ perceptions of need-support from the physical education (PE) teacher, basic psychological needs satisfaction, novelty, and variety satisfaction, as well as intrinsic motivation compared to baseline values. Although the hybrid TGfU/SE unit was effective in both genders, a large effect size was found for girls. Despite the existence of social and cultural stereotypes in team sports such as volleyball in favor of boys, results highlight the importance of developing hybrid TGfU/SE units to improve students’ motivational outcomes, especially in girls

Complexities underlying the breeding and deployment of Dutch elm disease resistant elms

Dutch elm disease (DED) is a vascular wilt disease caused by the pathogens Ophiostoma ulmi and Ophiostoma novo-ulmi with multiple ecological phases including pathogenic (xylem), saprotrophic (bark) and vector (beetle flight and beetle feeding wound) phases. Due to the two DED pandemics during the twentieth century the use of elms in landscape and forest restoration has declined significantly. However new initiatives for elm breeding and restoration are now underway in Europe and North America. Here we discuss complexities in the DED 'system' that can lead to unintended consequences during elm breeding and some of the wider options for obtaining durability or 'field resistance' in released material, including (1) the phenotypic plasticity of disease levels in resistant cultivars infected by O. novo-ulmi; (2) shortcomings in test methods when selecting for resistance; (3) the implications of rapid evolutionary changes in current O. novo-ulmi populations for the choice of pathogen inoculum when screening; (4) the possibility of using active resistance to the pathogen in the beetle feeding wound, and low attractiveness of elm cultivars to feeding beetles, in addition to resistance in the xylem; (5) the risk that genes from susceptible and exotic elms be introgressed into resistant cultivars; (6) risks posed by unintentional changes in the host microbiome; and (7) the biosecurity risks posed by resistant elm deployment. In addition, attention needs to be paid to the disease pressures within which resistant elms will be released. In the future, biotechnology may further enhance our understanding of the various resistance processes in elms and our potential to deploy trees with highly durable resistance in elm restoration. Hopefully the different elm resistance processes will prove to be largely under durable, additive, multigenic control. Elm breeding programmes cannot afford to get into the host-pathogen arms races that characterise some agricultural host-pathogen systems

Re-irradiation of silver nanoparticles obtained by laser ablation in water and assessment of their antibacterial effect

The rapid evolution of resistant bacteria is a huge problem in medicine because makes the treatment of infections more and more difficult. The bactericidal properties of noble metal nanoparticles could be a solution. In this work silver nanoparticles were produced by using two nanosecond Nd:YVO4 lasers operating at 1064 and 532 nm respectively to ablate a silver target submerged in pure de-ionized water. Part of the resulting colloidal solution was injected as a fine stream by a compressed air system and re-irradiated one and three times with the same laser to resize and get uniform nanoparticles. The obtained nanoparticles by ablation and re-irradiation consisted of crystalline Ag nanoparticles with a bimodal size distribution. The particle size has been reduced by subsequent laser re-irradiation with both laser sources, reaching a 40% of mean size reduction. Inhibitory effects on the proliferation of Staphylococcus aureus was demonstrated on silver nanoparticles obtained after re-irradiation with the infrared laser.Postprint (author's final draft

Spatial Analysis of the Relationship between Mortality from Cardiovascular and Cerebrovascular Disease and Drinking Water Hardness

Previously published scientific papers have reported a negative correlation between drinking water hardness and cardiovascular mortality. Some ecologic and case–control studies suggest the protective effect of calcium and magnesium concentration in drinking water. In this article we present an analysis of this protective relationship in 538 municipalities of Comunidad Valenciana (Spain) from 1991–1998. We used the Spanish version of the Rapid Inquiry Facility (RIF) developed under the European Environment and Health Information System (EUROHEIS) research project. The strategy of analysis used in our study conforms to the exploratory nature of the RIF that is used as a tool to obtain quick and flexible insight into epidemiologic surveillance problems. This article describes the use of the RIF to explore possible associations between disease indicators and environmental factors. We used exposure analysis to assess the effect of both protective factors—calcium and magnesium—on mortality from cerebrovascular (ICD-9 430–438) and ischemic heart (ICD-9 410–414) diseases. This study provides statistical evidence of the relationship between mortality from cardiovascular diseases and hardness of drinking water. This relationship is stronger in cerebrovascular disease than in ischemic heart disease, is more pronounced for women than for men, and is more apparent with magnesium than with calcium concentration levels. Nevertheless, the protective nature of these two factors is not clearly established. Our results suggest the possibility of protectiveness but cannot be claimed as conclusive. The weak effects of these covariates make it difficult to separate them from the influence of socioeconomic and environmental factors. We have also performed disease mapping of standardized mortality ratios to detect clusters of municipalities with high risk. Further standardization by levels of calcium and magnesium in drinking water shows changes in the maps when we remove the effect of these covariates

Dietary Fat Patterns and Outcomes in Acute Pancreatitis in Spain

Background/Objective: Evidence from basic and clinical studies suggests that unsaturated fatty acids (UFAs) might be relevant mediators of the development of complications in acute pancreatitis (AP). Objective: The aim of this study was to analyze outcomes in patients with AP from regions in Spain with different patterns of dietary fat intake. Materials and Methods: A retrospective analysis was performed with data from 1,655 patients with AP from a Spanish prospective cohort study and regional nutritional data from a Spanish cross-sectional study. Nutritional data considered in the study concern the total lipid consumption, detailing total saturated fatty acids, UFAs and monounsaturated fatty acids (MUFAs) consumption derived from regional data and not from the patient prospective cohort. Two multivariable analysis models were used: (1) a model with the Charlson comorbidity index, sex, alcoholic etiology, and recurrent AP; (2) a model that included these variables plus obesity. Results: In multivariable analysis, patients from regions with high UFA intake had a significantly increased frequency of local complications, persistent organ failure (POF), mortality, and moderate-to-severe disease in the model without obesity and a higher frequency of POF in the model with obesity. Patients from regions with high MUFA intake had significantly more local complications and moderate-to-severe disease; this significance remained for moderate-to-severe disease when obesity was added to the model. Conclusions: Differences in dietary fat patterns could be associated with different outcomes in AP, and dietary fat patterns may be a pre-morbid factor that determines the severity of AP. UFAs, and particulary MUFAs, may influence the pathogenesis of the severity of AP