105 research outputs found
Fine scale sedimentary sequences of Douro muddy complex (Northern Portuguese Continental Shelf)
Introducción
El parasitismo se define como una relación simbiótica enmarcada en una interacción trófica directa. Produce beneficio en una dirección (parásito) y algún tipo de perjuicio en la otra (hospedador), tales como injuria mecánica, utilización de nutrientes del hospedador, estimulación de reacciones inflamatorias o una respuesta inmune exagerada, con la consecuente desventaja para el hospedador (Roberts y Janovy, 2000; Bush y otros, 2001). El parasitismo también ha sido definido en términos de pérdida de energía, o de supervivencia más baja, o de reducción del potencial reproductivo del hospedador. Estos conceptos implican que un parásito tiene un efecto detrimental en la supervivencia y rango reproductivo de la pobl ación hospedadora, premisa central en los modelos ecológicos teóricos de las interacciones parásitohospedador (Bush y otros, 2001).Facultad de Ciencias Naturales y Muse
Introducción
El parasitismo se define como una relación simbiótica enmarcada en una interacción trófica directa. Produce beneficio en una dirección (parásito) y algún tipo de perjuicio en la otra (hospedador), tales como injuria mecánica, utilización de nutrientes del hospedador, estimulación de reacciones inflamatorias o una respuesta inmune exagerada, con la consecuente desventaja para el hospedador (Roberts y Janovy, 2000; Bush y otros, 2001). El parasitismo también ha sido definido en términos de pérdida de energía, o de supervivencia más baja, o de reducción del potencial reproductivo del hospedador. Estos conceptos implican que un parásito tiene un efecto detrimental en la supervivencia y rango reproductivo de la pobl ación hospedadora, premisa central en los modelos ecológicos teóricos de las interacciones parásitohospedador (Bush y otros, 2001).Facultad de Ciencias Naturales y Muse
Introducción
El parasitismo se define como una relación simbiótica enmarcada en una interacción trófica directa. Produce beneficio en una dirección (parásito) y algún tipo de perjuicio en la otra (hospedador), tales como injuria mecánica, utilización de nutrientes del hospedador, estimulación de reacciones inflamatorias o una respuesta inmune exagerada, con la consecuente desventaja para el hospedador (Roberts y Janovy, 2000; Bush y otros, 2001). El parasitismo también ha sido definido en términos de pérdida de energía, o de supervivencia más baja, o de reducción del potencial reproductivo del hospedador. Estos conceptos implican que un parásito tiene un efecto detrimental en la supervivencia y rango reproductivo de la pobl ación hospedadora, premisa central en los modelos ecológicos teóricos de las interacciones parásitohospedador (Bush y otros, 2001).Facultad de Ciencias Naturales y Muse
The climate of the Common Era off the Iberian Peninsula
The Mediterranean region is a climate hot spot, sensitive not only to global warming but also to water availability. In this work we document major temperature and precipitation changes in the Iberian Peninsula and margin during the last 2000 years and propose an interplay of the North Atlantic internal variability with the three atmospheric circulation modes (ACMs), (North Atlantic Oscillation (NAO), east atlantic (EA) and Scandinavia (SCAND)) to explain the detected climate variability. We present reconstructions of sea surface temperature (SST derived from alkenones) and on-land precipitation (estimated from higher plant n-alkanes and pollen data) in sedimentary sequences recovered along the Iberian Margin between the south of Portugal (Algarve) and the northwest of Spain (Galiza) (36 to 42 degrees N). A clear long-term cooling trend, from 0 CE to the beginning of the 20th century, emerges in all SST records and is considered to be a reflection of the decrease in the Northern Hemisphere summer insolation that began after the Holocene optimum. Multi-decadal/centennial SST variability follows other records from Spain, Europe and the Northern Hemisphere. Warm SSTs throughout the first 1300 years encompass the Roman period (RP), the Dark Ages (DA) and the Medieval Climate Anomaly (MCA). A cooling initiated at 1300 CE leads to 4 centuries of colder SSTs contemporary with the Little Ice Age (LIA), while a climate warming at 1800 CE marks the beginning of the modern/Industrial Era. Novel results include two distinct phases in the MCA: an early period (900-1100 years) characterized by intense precipitation/flooding and warm winters but a cooler spring-fall season attributed to the interplay of internal oceanic variability with a positive phase in the three modes of atmospheric circulation (NAO, EA and SCAND). The late MCA is marked by cooler and relatively drier winters and a warmer spring-fall season consistent with a shift to a negative mode of the SCAND. The Industrial Era reveals a clear difference between the NW Iberia and the Algarve records. While off NW Iberia variability is low, the Algarve shows large-amplitude decadal variability with an inverse relationship between SST and river input. Such conditions suggest a shift in the EA mode, from negative between 1900 and 1970 CE to positive after 1970, while NAO and SCAND remain in a positive phase. The particularly noticeable rise in SST at the Algarve site by the mid-20th century (+/- 1970), provides evidence for a regional response to the ongoing climate warming. The reported findings have implications for decadal-scale predictions of future climate change in the Iberian Peninsula./2004]; CALIBERIA (FCT) [PTDC/MAR/102045/2008]; CALIBERIA [COMPETE/FEDER-FCOMP-01-0124-FEDER-010599]; CI-IMAR [20132017 CIMAR]; CCMAR [PEstC/MAR/LA0015/2013]; IPMA, within the EU project SAFI [FP7-SPACE-2013-1, 607155]; [SFRH/BPD/36615/2007]; [SFRH/BPD/66025/2009]; [SFRH/BPD/26525/2006]; [SFRH/BPDINGMAR (FCT ARIPIPI Program - Support for State Labs Development); HOLSMEER [EVK2-CT-2000-00060]; CLIMHOL [PTDC/AAC-CLI/100157/2008]; MINO-MINHO [0234_NATURA_MM_1_E]; POPEI [PDCT/MAR/55618/111433/2015]info:eu-repo/semantics/publishedVersio
Microarray Analysis on Human Neuroblastoma Cells Exposed to Aluminum, β1–42-Amyloid or the β1–42-Amyloid Aluminum Complex
BACKGROUND: A typical pathological feature of Alzheimer's disease (AD) is the appearance in the brain of senile plaques made up of β-amyloid (Aβ) and neurofibrillary tangles. AD is also associated with an abnormal accumulation of some metal ions, and we have recently shown that one of these, aluminum (Al), plays a relevant role in affecting Aβ aggregation and neurotoxicity. METHODOLOGY: In this study, employing a microarray analysis of 35,129 genes, we investigated the effects induced by the exposure to the Aβ(1-42)-Al (Aβ-Al) complex on the gene expression profile of the neuronal-like cell line, SH-SY5Y. PRINCIPAL FINDINGS: The microarray assay indicated that, compared to Aβ or Al alone, exposure to Aβ-Al complex produced selective changes in gene expression. Some of the genes selectively over or underexpressed are directly related to AD. A further evaluation performed with Ingenuity Pathway analysis revealed that these genes are nodes of networks and pathways that are involved in the modulation of Ca(2+) homeostasis as well as in the regulation of glutamatergic transmission and synaptic plasticity. CONCLUSIONS AND SIGNIFICANCE: Aβ-Al appears to be largely involved in the molecular machinery that regulates neuronal as well as synaptic dysfunction and loss. Aβ-Al seems critical in modulating key AD-related pathways such as glutamatergic transmission, Ca(2+) homeostasis, oxidative stress, inflammation, and neuronal apoptosis
Essential oils: pharmaceutical applications and encapsulation strategies into lipid-based delivery systems
Essential oils are being studied for more than 60 years, but a growing interest has emerged in the recent decades due to a desire for a rediscovery of natural remedies. Essential oils are known for millennia and, already in prehistoric times, they were used for medicinal and ritual purposes due to their therapeutic properties. Using a variety of methods refined over the centuries, essential oils are extracted from plant raw materials: the choice of the extraction method is decisive, since it determines the type, quantity, and stereochemical structure of the essential oil molecules. To these components belong all properties that make essential oils so interesting for pharmaceutical uses; the most investigated ones are antioxidant, anti-inflammatory, antimicrobial, wound-healing, and anxiolytic activities. However, the main limitations to their use are their hydrophobicity, instability, high volatility, and risk of toxicity. A successful strategy to overcome these limitations is the encapsulation within delivery systems, which enable the increase of essential oils bioavailability and improve their chemical stability, while reducing their volatility and toxicity. Among all the suitable platforms, our review focused on the lipid-based ones, in particular micro- and nanoemulsions, liposomes, solid lipid nanoparticles, and nanostructured lipid carriers.This work was supported by a grant from the Italian Ministry of Research [Grant PRIN2017 #20173ZECCM Tracking biological barriers to antigen delivery by nanotechnological vaccines(NanoTechVax)] and by Research Funding for University of Catania (Piano per la Ricerca 2016–2018—Linea Di Intervento 2 “Dotazione Ordinaria” cod. 57722172106). Cinzia Cimino was supported bythe PhD program in Biotechnology, XXXVI cycle, University of Cataniainfo:eu-repo/semantics/publishedVersio
Work Function Tuning in Hydrothermally Synthesized Vanadium-Doped MoO3 and Co3O4 Mesostructures for Energy Conversion Devices
The wide interest in developing green energy technologies stimulates the scientific community to seek, for devices, new substitute material platforms with a low environmental impact, ease of production and processing and long-term stability. The synthesis of metal oxide (MO) semiconductors fulfils these requirements and efforts are addressed towards optimizing their functional properties through the improvement of charge mobility or energy level alignment. Two MOs have rising perspectives for application in light harvesting devices, mainly for the role of charge selective layers but also as light absorbers, namely MoO3 (an electron blocking layer) and Co3O4 (a small band gap semiconductor). The need to achieve better charge transport has prompted us to explore strategies for the doping of MoO3 and Co3O4 with vanadium (V) ions that, when combined with oxygen in V2O5, produce a high work function MO. We report on subcritical hydrothermal synthesis of V-doped mesostructures of MoO3 and of Co3O4, in which a tight control of the doping is exerted by tuning the relative amounts of reactants. We accomplished a full analytical characterization of these V-doped MOs that unambiguously demonstrates the incorporation of the vanadium ions in the host material, as well as the effects on the optical properties and work function. We foresee a promising future use of these materials as charge selective materials in energy devices based on multilayer structures
Work Function Tuning in Hydrothermally Synthesized Vanadium-Doped MoO3 and Co3O4 Mesostructures for Energy Conversion Devices
The wide interest in developing green energy technologies stimulates the scientific community to seek, for devices, new substitute material platforms with a low environmental impact, ease of production and processing and long-term stability. The synthesis of metal oxide (MO) semiconductors fulfils these requirements and efforts are addressed towards optimizing their functional properties through the improvement of charge mobility or energy level alignment. Two MOs have rising perspectives for application in light harvesting devices, mainly for the role of charge selective layers but also as light absorbers, namely MoO3 (an electron blocking layer) and Co3O4 (a small band gap semiconductor). The need to achieve better charge transport has prompted us to explore strategies for the doping of MoO3 and Co3O4 with vanadium (V) ions that, when combined with oxygen in V2O5, produce a high work function MO. We report on subcritical hydrothermal synthesis of V-doped mesostructures of MoO3 and of Co3O4, in which a tight control of the doping is exerted by tuning the relative amounts of reactants. We accomplished a full analytical characterization of these V-doped MOs that unambiguously demonstrates the incorporation of the vanadium ions in the host material, as well as the effects on the optical properties and work function. We foresee a promising future use of these materials as charge selective materials in energy devices based on multilayer structures
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