2,275 research outputs found

    Spectroscopy of vibrational modes in metal nanoshells

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    We study the spectrum of vibrational modes in metal nanoparticles with a dielectric core. Vibrational modes are excited by the rapid heating of the particle lattice that takes place after laser excitation, and can be monitored by means of pump-probe spectroscopy as coherent oscillations of transient optical spectra. In nanoshells, the presence of two metal surfaces results in a substantially different energy spectrum of acoustic vibrations than for solid particles. We calculated the energy spectrum as well as the damping of nanoshell vibrational modes. The oscillator strength of fundamental breathing mode is larger than that in solid nanoparticles. At the same time, in very thin nanoshells, the fundamental mode is overdamped due to instantaneous energy transfer to the surrounding medium

    Polygalacturonase gene FaPG1 downregulation is related to increased strawberry fruit resistance to fungal decay

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    Plant health is a major target in breading programs because crops are under constant biotic stress, and climate change is exacerbating pests and disease negative impacts in agriculture. Obtaining crop varieties armed with better defences is a potential strategy to reduce losses from biotic attacks. Plant cell walls perform crucial roles on many physiological processes, and under biotic stress, play crucial defensive roles as protecting barrier, as well as a source of integrity signalling molecules. Plant immunity has evolved a complex multi-layered system which first line of defence is initiated by conserved molecular patterns coming from pathogens, named pathogen-associated molecular patterns or PAMPs, or from their own corrupted cell walls due to pathogen invasion, named damaged-associated molecular patterns or DAMPs. Accumulating evidence from cell wall mutants has unveiled several components and mechanisms of plant innate immunity under biotic stresses, mostly in Arabidopsis, but still little is known from species with agronomic interest as strawberry. Our group has an established strawberry transgenic collection of cell wall mutants. Among them, RNAseq expression profiles of FaPG1 mutants has shown downregulation of other cell wall related genes than PG [1], but the mechanisms underneath required further investigation. FaPG genes code for enzymes with endo-PG activity related to oligogalacturonic acid (OGA) release, which would be associated to the changes in gene expression of other cell wall genes than FaPG. In this work, postharvest assays of FaPG1 fruits showed not only the increased fruit firmness typical of this mutant, but a better resistance to fungal infections by Botrytis cinerea, enhancing fruit shelf life in comparison with control fruits.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

    Spatters and Spills: Spreading Dynamics for Partially Wetting Droplets

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    We present a solvable model inspired by dimensional analysis for the time-dependent spreading of droplets that partially wet a substrate, where the spreading eventually stops and the contact angle reaches a nonzero equilibrium value. We separately consider small droplets driven by capillarity and large droplets driven by gravity. To explore both regimes, we first measure the equilibrium radius vs a comprehensive range of droplet volumes for four household fluids, and we compare the results with predictions based on minimizing the sum of gravitational and interfacial energies. The agreement is good and gives a reliable measurement of an equilibrium contact angle that is consistent in both small and large droplet regimes. Next, we use energy considerations to develop equations of motion for the time dependence of the spreading, in both regimes, where the driving forces are balanced against viscous drag in the bulk of the droplet and by friction at the moving contact line. Our approach leads to explicit prediction of the functional form of the spreading dynamics. It successfully describes prior data for a small capillary-driven droplet, and it fits well to new data we obtain for large gravity-driven droplets with a wide range of volumes. While our prediction for the dynamics of small capillary-driven droplets assumes the case of thin nearly wetting droplets, with a small contact angle, this restriction is not otherwise invoked

    Spatters and Spills: Spreading Dynamics for Partially Wetting Droplets

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    We present a solvable model inspired by dimensional analysis for the time-dependent spreading of droplets that partially wet a substrate, where the spreading eventually stops and the contact angle reaches a nonzero equilibrium value. We separately consider small droplets driven by capillarity and large droplets driven by gravity. To explore both regimes, we first measure the equilibrium radius vs a comprehensive range of droplet volumes for four household fluids, and we compare the results with predictions based on minimizing the sum of gravitational and interfacial energies. The agreement is good and gives a reliable measurement of an equilibrium contact angle that is consistent in both small and large droplet regimes. Next, we use energy considerations to develop equations of motion for the time dependence of the spreading, in both regimes, where the driving forces are balanced against viscous drag in the bulk of the droplet and by friction at the moving contact line. Our approach leads to explicit prediction of the functional form of the spreading dynamics. It successfully describes prior data for a small capillary-driven droplet, and it fits well to new data we obtain for large gravity-driven droplets with a wide range of volumes. While our prediction for the dynamics of small capillary-driven droplets assumes the case of thin nearly wetting droplets, with a small contact angle, this restriction is not otherwise invoked

    Scissors modes in triaxial metal clusters

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    We study the scissors mode (orbital M1 excitations) in small Na clusters, triaxial metal clusters Na12{\rm Na}_{12} and Na16{\rm Na}_{16} and the close-to-spherical Na9+{{\rm Na}_9}^+, all described in DFT with detailed ionic background. The scissors modes built on spin-saturated ground and spin-polarized isomeric states are analyzed in virtue of both macroscopic collective and microscopic shell-model treatments. It is shown that the mutual destruction of Coulomb and the exchange-correlation parts of the residual interaction makes the collective shift small and the net effect can depend on details of the actual excited state. The crosstalk with dipole and spin-dipole modes is studied in detail. In particular, a strong crosstalk with spin-dipole negative-parity mode is found in the case of spin-polarized states. Triaxiality and ionic structure considerably complicate the scissors response, mainly at expense of stronger fragmentation of the strength. Nevertheless, even in these complicated cases the scissors mode is mainly determined by the global deformation. The detailed ionic structure destroys the spherical symmetry and can cause finite M1 response (transverse optical mode) even in clusters with zero global deformation. But its strength turns out to be much smaller than for the genuine scissors modes in deformed systems.Comment: 17 pages, 5 figure

    The BRENDA Tissue Ontology (BTO): the first all-integrating ontology of all organisms for enzyme sources

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    BTO, the BRENDA Tissue Ontology (http://www.BTO.brenda-enzymes.org) represents a comprehensive structured encyclopedia of tissue terms. The project started in 2003 to create a connection between the enzyme data collection of the BRENDA enzyme database and a structured network of source tissues and cell types. Currently, BTO contains more than 4600 different anatomical structures, tissues, cell types and cell lines, classified under generic categories corresponding to the rules and formats of the Gene Ontology Consortium and organized as a directed acyclic graph (DAG). Most of the terms are endowed with comments on their derivation or definitions. The content of the ontology is constantly curated with ∼1000 new terms each year. Four different types of relationships between the terms are implemented. A versatile web interface with several search and navigation functionalities allows convenient online access to the BTO and to the enzymes isolated from the tissues. Important areas of applications of the BTO terms are the detection of enzymes in tissues and the provision of a solid basis for text-mining approaches in this field. It is widely used by lab scientists, curators of genomic and biochemical databases and bioinformaticians. The BTO is freely available at http://www.obofoundry.org

    Ten Years’ Experience with Alendronate for Osteoporosis in Postmenopausal Women

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    Background Antiresorptive agents are widely used to treat osteoporosis. We report the results of a multinational randomized, double-blind study, in which postmenopausal women with osteoporosis were treated with alendronate for up to 10 years. Methods The initial three-year phase of the study compared three daily doses of alendronate with placebo. Women in the original placebo group received alendronate in years 4 and 5 and then were discharged. Women in the original active-treatment groups continued to receive alendronate during the initial extension (years 4 and 5). In two further extensions (years 6 and 7, and 8 through 10), women who had received 5 mg or 10 mg of alendronate daily continued on the same treatment. Women in the discontinuation group received 20 mg of alendronate daily for two years and 5 mg daily in years 3, 4, and 5, followed by five years of placebo. Randomized group assignments and blinding were maintained throughout the 10 years. We report results for the 247 women who participated in all four phases of the study. Results Treatment with 10 mg of alendronate daily for 10 years produced mean increases in bone mineral density of 13.7 percent at the lumbar spine (95 percent confidence interval, 12.0 to 15.5 percent), 10.3 percent at the trochanter (95 percent confidence interval, 8.1 to 12.4 percent), 5.4 percent at the femoral neck (95 percent confidence interval, 3.5 to 7.4 percent), and 6.7 percent at the total proximal femur (95 percent confidence interval, 4.4 to 9.1 percent) as compared with base-line values; smaller gains occurred in the group given 5 mg daily. The discontinuation of alendronate resulted in a gradual loss of effect, as measured by bone density and biochemical markers of bone remodeling. Safety data, including fractures and stature, did not suggest that prolonged treatment resulted in any loss of benefit. Conclusions The therapeutic effects of alendronate were sustained, and the drug was well tolerated over a 10-year period. The discontinuation of alendronate resulted in the gradual loss of its effects

    Leucemia mielomonocítica aguda y drepanocitosis no tratada con hidroxiurea: A propósito de un caso / Acute Melanocytic Leukemia and Drepanocytosis non-treated with hydroxyurea a case report

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    Las enfermedades malignas asociadas a la anemia drepanocítica han sido reportadas previamente en un reducido número de pacientes, con el advenimiento de la terapia con hidroxiurea se ha observado un incremento en el riesgo de cáncer en estos enfermos; en nuestro caso clínico no se recoge el antecedente de ingestión de este medicamento. Paciente masculino de 25 años de edad, que acude con crisis hepática, con aumento de ictericia y bilirrubina a expensas de la directa, valores elevados de la transaminasa, hepatomegalia y caída de las cifras de hemoglobina a 40 g/L, blastos de un diámetro de 25 mc, granulares, algunos con núcleos de aspecto monocitoide, componente monocítico en periferia igual a 15%, conteo de leucocitos 120 x109/l,medulograma 80% de células blásticas, componente monocítico mayor del 20%, concluyéndose como Leucemia Mielomonocítica Aguda (LMA M4) según estudios citoquímicos diagnósticos además de un aumento de la lisozima y muramidasa superior a 13 mg lis/ml de plasma (Na acetatoesterasas ) positivo (NASA). Se realiza la plasmaféresis y la exanguinotransfusión haciendo dos recambios con amplia hidratación sin respuesta satisfactoria; el paciente fallece el tercer día del diagnóstico debido a Insuficiencia Respiratoria Aguda. Por lo inusual que resulta y por no existir casos reportados en la literatura Internacional de Síndrome Mieloproliferativo Agudo asociado a la Drepanocitosis no tratados con hidroxiurea, los autores presentan este caso clínico. Palabras clave: Hemoglobinopatía, drepanocitosis, síndrome mieloproliferativo agudo. ABSTRACTMalignant diseases related to sickle-cell anemia have been previously reported in a reduced number of patients, the risk of suffering from cancer in those patients have increased with the advent of the hydroxyurea treatment. In this case no evidence of being taken this medication was proved. A 25-years old male presenting hepatic crisis, jaundice, hyperbilirubinemia, high levels of transaminase, hepatomegaly and low red blood cell counts (40 g/l), blast cells of 25 µm in diameter, granular cell presenting nucleus of monocytic-like cells (some of them), monocytic component in periphery equal to 15 %, leucocytes counts 120x109/l, medullogram: 80 % of blast cells, monocytic component greater than 20 %, concluded as Acute Myelomonocytic Leukemia (AML M4) diagnostic cyto-chemical studies showed an increase of lysozyme and muramidase higher than 13 mg lis/ml of plasma (a positive Na acetatoesterases). A plasmapheresis and ex-transfusion and two rechanges, deep rehydration. No satisfactory response was observed and the patient died on the third day with a diagnose of acute respiratory insufficiency. Because of this unsual disorder and no other cases described by the medical literature as an Acute Myeloproliferative Syndrome in association to Drepanocytosis non-treated with Hydroxyurea motivated the authors to present this case report. Key words: Hemoglobinopathies; drepanocytosis, acute myeloproliferative syndrome

    Leucemia mielomonocítica aguda y drepanocitosis no tratada con hidroxiurea: A propósito de un caso / Acute Melanocytic Leukemia and Drepanocytosis non-treated with hydroxyurea a case report

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    Las enfermedades malignas asociadas a la anemia drepanocítica han sido reportadas previamente en un reducido número de pacientes, con el advenimiento de la terapia con hidroxiurea se ha observado un incremento en el riesgo de cáncer en estos enfermos; en nuestro caso clínico no se recoge el antecedente de ingestión de este medicamento. Paciente masculino de 25 años de edad, que acude con crisis hepática, con aumento de ictericia y bilirrubina a expensas de la directa, valores elevados de la transaminasa, hepatomegalia y caída de las cifras de hemoglobina a 40 g/L, blastos de un diámetro de 25 mc, granulares, algunos con núcleos de aspecto monocitoide, componente monocítico en periferia igual a 15%, conteo de leucocitos 120 x109/l,medulograma 80% de células blásticas, componente monocítico mayor del 20%, concluyéndose como Leucemia Mielomonocítica Aguda (LMA M4) según estudios citoquímicos diagnósticos además de un aumento de la lisozima y muramidasa superior a 13 mg lis/ml de plasma (Na acetatoesterasas ) positivo (NASA). Se realiza la plasmaféresis y la exanguinotransfusión haciendo dos recambios con amplia hidratación sin respuesta satisfactoria; el paciente fallece el tercer día del diagnóstico debido a Insuficiencia Respiratoria Aguda. Por lo inusual que resulta y por no existir casos reportados en la literatura Internacional de Síndrome Mieloproliferativo Agudo asociado a la Drepanocitosis no tratados con hidroxiurea, los autores presentan este caso clínico. Palabras clave: Hemoglobinopatía, drepanocitosis, síndrome mieloproliferativo agudo. ABSTRACTMalignant diseases related to sickle-cell anemia have been previously reported in a reduced number of patients, the risk of suffering from cancer in those patients have increased with the advent of the hydroxyurea treatment. In this case no evidence of being taken this medication was proved. A 25-years old male presenting hepatic crisis, jaundice, hyperbilirubinemia, high levels of transaminase, hepatomegaly and low red blood cell counts (40 g/l), blast cells of 25 µm in diameter, granular cell presenting nucleus of monocytic-like cells (some of them), monocytic component in periphery equal to 15 %, leucocytes counts 120x109/l, medullogram: 80 % of blast cells, monocytic component greater than 20 %, concluded as Acute Myelomonocytic Leukemia (AML M4) diagnostic cyto-chemical studies showed an increase of lysozyme and muramidase higher than 13 mg lis/ml of plasma (a positive Na acetatoesterases). A plasmapheresis and ex-transfusion and two rechanges, deep rehydration. No satisfactory response was observed and the patient died on the third day with a diagnose of acute respiratory insufficiency. Because of this unsual disorder and no other cases described by the medical literature as an Acute Myeloproliferative Syndrome in association to Drepanocytosis non-treated with Hydroxyurea motivated the authors to present this case report. Key words: Hemoglobinopathies; drepanocytosis, acute myeloproliferative syndrome

    The long and the short of it: Mechanisms of synchronous and compensatory dynamics across temporal scales

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    Synchronous dynamics (fluctuations that occur in unison) are universal phenomena with widespread implications for ecological stability. Synchronous dynamics can amplify the destabilizing effect of environmental variability on ecosystem functions such as productivity, whereas the inverse, compensatory dynamics, can stabilize function. Here we combine simulation and empirical analyses to elucidate mechanisms that underlie patterns of synchronous versus compensatory dynamics. In both simulated and empirical communities, we show that synchronous and compensatory dynamics are not mutually exclusive but instead can vary by timescale. Our simulations identify multiple mechanisms that can generate timescale-specific patterns, including different environmental drivers, diverse life histories, dispersal, and non-stationary dynamics. We find that traditional metrics for quantifying synchronous dynamics are often biased toward long-term drivers and may miss the importance of short-term drivers. Our findings indicate key mechanisms to consider when assessing synchronous versus compensatory dynamics and our approach provides a pathway for disentangling these dynamics in natural systems
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