69 research outputs found

    Intermatrix synthesis: easy technique permitting preparation of polymer-stabilized nanoparticles with desired composition and structure

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    The synthesis of polymer-stabilized nanoparticles (PSNPs) can be successfully carried out using intermatrix synthesis (IMS) technique, which consists in sequential loading of the functional groups of a polymer with the desired metal ions followed by nanoparticles (NPs) formation stage. After each metal-loading-NPs-formation cycle, the functional groups of the polymer appear to be regenerated. This allows for repeating the cycles to increase the NPs content or to obtain NPs with different structures and compositions (e.g. core-shell or core-sandwich). This article reports the results on the further development of the IMS technique. The formation of NPs has been shown to proceed by not only the metal reduction reaction (e.g. Cu0-NPs) but also by the precipitation reaction resulting in the IMS of PSNPs of metal salts (e.g. CuS-NPs)

    Seasonal patterns of suicides over the period of socio-economic transition in Lithuania

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    BACKGROUND: In Lithuania, suicides are a grave public health problem, requiring more extensive investigation. The aim of the study was to assess the seasonal variations of suicides in Lithuania throughout the years 1993–2002, describing patterns by gender, age and method of suicide. METHODS: The study material consisted of all registered suicides (n = 16,147) committed throughout 1993–2002 in Lithuania. Smoothed trends were inspected. The seasonal effect was explored using monthly ratio statistics and spectral analysis. RESULTS: Suicides in Lithuania have a distinct annual rhythm with peaks in summer and troughs in December. The December frequencies fell by more than 23% in men and 30% in women, while June peak reached nearly 23% in men and July peak exceeded 29% in women, compare with the average levels, (p < 0.05). Hanging was the most common method of suicide both in men and women comprising up to 90% among all suicides in 1998–2002. Among different methods, only hanging suicides showed significant seasonal variations, especially in men. The seasonal amplitude has decreased over time. CONCLUSION: Substantial seasonal variations in suicides were associated with a high proportion of hanging. Extremely high suicide rates in Lithuania require further extensive studies and urgent preventive programs, taking into account the suggestions of this survey

    Catalysing sustainable fuel and chemical synthesis

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    Concerns over the economics of proven fossil fuel reserves, in concert with government and public acceptance of the anthropogenic origin of rising CO2 emissions and associated climate change from such combustible carbon, are driving academic and commercial research into new sustainable routes to fuel and chemicals. The quest for such sustainable resources to meet the demands of a rapidly rising global population represents one of this century’s grand challenges. Here, we discuss catalytic solutions to the clean synthesis of biodiesel, the most readily implemented and low cost, alternative source of transportation fuels, and oxygenated organic molecules for the manufacture of fine and speciality chemicals to meet future societal demands

    Atopic dermatitis : a cutaneous or systemic disease? The search for answers in the history of Dermatology

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    A dermatite atópica é doença inflamatória cutânea associada à atopia, predisposição a produzir resposta IgE a alérgenos ambientais, constituindo uma das manifestações das doenças atópicas, junto com a asma e a rinite alérgica. A dermatite atópica é caracterizada por episódios recorrentes de eczema associado a prurido, acometendo superfície cutânea geneticamente alterada, induzindo, por fenômenos imunológicos, a presença de inflamação. Trata-se de doença multifatorial, com enfoque nas alterações sistêmicas e alérgicas ou nas manifestações cutâneas, de acordo com diferentes visões da doença. A conceituação da dermatite atópica é importante, porque a conduta terapêutica pode variar segundo essas duas formas diferentes de analisá-la. Autores modernos discutem extensivamente esses aspectos sem, contudo, alcançar uma conclusão sobre a dermatite atópica como doença sistêmica ou cutânea. A procura dos conceitos sobre a doença, desde os primeiros relatos, associada à evolução do pensamento na dermatologia, poderia esclarecer a origem dessas dúvidas. Uma análise histórica demonstra que a dermatite atópica tem seus conceitos atuais oriundos dos estudos de diversos pensadores, que, em diferentes momentos históricos, descreveram a doença, e que muito do que acreditamos atualmente tem, nesses escritos, seus fundamentos.Atopic dermatitis is an inflammatory disease associated to atopy, which is a predisposition to produce an IgE response to environmental allergens and considered one of the manifestations of the atopic diseases, including asthma and allergic rhinitis. Atopic dermatitis is characterized by recurrent eczema flares, associated to pruritus, affecting a genetically disrupted skin surface, inducing, by immunological phenomena, the onset of inflammation. It is a multifactorial disease, with an emphasis on systemic and allergic alterations or skin manifestations, according to different concepts. The definition of atopic dermatitis is important, since its management may vary according to these two different points of view. Modern authors have extensively discussed these concepts, though with no conclusion as to its nature - systemic or cutaneous disease. The search for concepts about the disease, since its first descriptions, associated to the evolution of the dermatology rationale through history, may help understand the origin of these doubts. A historical analysis demonstrates that the currently accepted concepts of atopic dermatitis have their background from different researchers, who, at different historical moments, described the disease, and a great part of our beliefs about atopic dermatitis are related to these ancient writings

    A remarkable synergistic effect at the transcriptomic level in peach fruits doubly infected by Prunus necrotic ringspot virus and Peach latent mosaic viroid

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    [EN] Background: Microarray profiling is a powerful technique to investigate expression changes of large amounts of genes in response to specific environmental conditions. The majority of the studies investigating gene expression changes in virus-infected plants are limited to interactions between a virus and a model host plant, which usually is Arabidopsis thaliana or Nicotiana benthamiana. In the present work, we performed microarray profiling to explore changes in the expression profile of field-grown Prunus persica (peach) originating from Chile upon single and double infection with Prunus necrotic ringspot virus (PNRSV) and Peach latent mosaic viroid (PLMVd), worldwide natural pathogens of peach trees. Results: Upon single PLMVd or PNRSV infection, the number of statistically significant gene expression changes was relatively low. By contrast, doubly-infected fruits presented a high number of differentially regulated genes. Among these, down-regulated genes were prevalent. Functional categorization of the gene expression changes upon double PLMVd and PNRSV infection revealed protein modification and degradation as the functional category with the highest percentage of repressed genes whereas induced genes encoded mainly proteins related to phosphate, C-compound and carbohydrate metabolism and also protein modification. Overrepresentation analysis upon double infection with PLMVd and PNRSV revealed specific functional categories over- and underrepresented among the repressed genes indicating active counter-defense mechanisms of the pathogens during infection. Conclusions: Our results identify a novel synergistic effect of PLMVd and PNRSV on the transcriptome of peach fruits. We demonstrate that mixed infections, which occur frequently in field conditions, result in a more complex transcriptional response than that observed in single infections. Thus, our data demonstrate for the first time that the simultaneous infection of a viroid and a plant virus synergistically affect the host transcriptome in infected peach fruits. These field studies can help to fully understand plant-pathogen interactions and to develop appropriate crop protection strategies.We thank Drs M.A. Perez-Amador y J. Gadea for helping in the result analysis. This work was supported by grant BIO2011-25018 from the Spanish granting agency Direccion General de Investigacion Cientifica for the transcriptomic analyses and from the grant 2009CL0020 from the bilateral project INIA-Chile/CSIC-Spain for the phytosanitary evaluation. MC Herranz was the recipient of a contract from the Juan de la Cierva program of the Ministerio de Educacion y Ciencia of Spain.Herranz Gordo, MDC.; Niehl, A.; Rosales, M.; Fiore, N.; Zamorano, A.; Granell Richart, A.; Pallás Benet, V. (2013). 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    金属氧化物纳米材料的设计与合成策略

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    Dolphin predation pressure on pelagic and demersal fish in the northwestern Mediterranean Sea

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    Sardine Sardina pilchardus, anchovy Engraulis encrasicolus and European hake Merluccius merluccius represent a significant part of the commercial landings in the Gulf of Lions (northwestern Mediterranean Sea). However, their stocks have shown severe declines during the last decades due to fishing pressure and/or environmental changes. The aim of this study was to estimate the current predation pressure of bottlenose dolphins Tursiops truncatus and striped dolphins Stenella coeruleoalba - which are abundant in the area-on sardine, anchovy and hake. To do so, we developed an original approach based on several data sets and models (aerial surveys, stomach contents, allometric and stock assessment models) and Monte Carlo simulations to incorporate various sources of uncertainty due to data limitations. Despite the uncertainties, the results showed that dolphin predation pressure on sardine and anchovy was extremely low in the Gulf of Lions (all simulations <0.5 % of the available stock), indicating little impact of dolphins on those populations. However, significant predation pressure on hake (median value: 23 %) was detected, a value which might have doubled in the last 30 yr because of hake overfishing. Overexploitation has thus reinforced the natural mortality of hake due to dolphin predation, but this predation pressure remains 2 to 3 times lower than that exerted by fisheries

    Overfishing of small pelagic fishes increases trophic overlap between immature and mature striped dolphins in the Mediterranean Sea

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    The interactions among diet, ecology, physiology, and biochemistry affect N and C stable isotope signatures in animal tissues. Here, we examined if ecological segregation among animals in relation to sex and age existed by analyzing the signatures of δ15N and δ13C in the muscle of Western Mediterranean striped dolphins. Moreover, we used a Bayesian mixing model to study diet composition and investigated potential dietary changes over the last two decades in this population. For this, we compared isotope signatures in samples of stranded dolphins obtained during two epizootic events occurring in 1990 and 2007–2008. Mean δ13C values for females and males were not significantly different, but age-related variation indicated δ13C enrichment in both sexes, suggesting that females and males most likely fed in the same general areas, increasing their consumption of benthic prey with age. Enrichment of δ15N was only observed in females, suggesting a preference for larger or higher trophic level prey than males, which could reflect different nutritional requirements. δ13C values showed no temporal variation, although the mean δ15N signature decreased from 1990 to 2007–2008, which could indicate a dietary shift in the striped dolphin over the last two decades. The results of SIAR indicated that in 1990, hake and sardine together contributed to 60% on the diet of immature striped dolphins, and close to 90% for mature striped dolphins. Conversely, the diet of both groups in 2007–2008 was more diverse, as hake and sardine contributed to less than 40% of the entire diet. These results suggest a dietary change that was possibly related to changes in food availability, which is consistent with the depletion of sardine stocks by fishing
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