175 research outputs found

    Bending strain-tunable magnetic anisotropy in Co2FeAl Heusler thin film on Kapton

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    Bending effect on the magnetic anisotropy in 20 nm Co2_{2}FeAl Heusler thin film grown on Kapton\textregistered{} has been studied by ferromagnetic resonance and glued on curved sample carrier with various radii. The results reported in this letter show that the magnetic anisotropy is drastically changed in this system by bending the thin films. This effect is attributed to the interfacial strain transmission from the substrate to the film and to the magnetoelastic behavior of the Co2_{2}FeAl film. Moreover two approaches to determine the in-plane magnetostriction coefficient of the film, leading to a value that is close to λCFA=14×106\lambda^{CFA}=14\times10^{-6}, have been proposed.Comment: 4 pages, 4 figure

    Voltage controlled terahertz transmission through GaN quantum wells

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    We report measurements of radiation transmission in the 0.220--0.325 THz frequency domain through GaN quantum wells grown on sapphire substrates at room and low temperatures. A significant enhancement of the transmitted beam intensity with the applied voltage on the devices under test is found. For a deeper understanding of the physical phenomena involved, these results are compared with a phenomenological theory of light transmission under electric bias relating the transmission enhancement to changes in the differential mobility of the two-dimensional electron gas

    Efectos del programa de HHSS-MINSA en el desarrollo de habilidades sociales de los estudiantes de educación secundaria en la Institución Educativa Fuerza Aérea del Perú “José Quiñones”, La Molina, 2014

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    El presente trabajo de investigación titulado: “Efectos del programa HHSS-MINSA en el desarrollo de habilidades sociales de los estudiantes de educación secundaria en la Institución Educativa Fuerza Aérea del Perú “José Quiñones”, La Molina, 2014”; tiene por objetivo evaluar los efectos del programa de HHSS - MINSA en el desarrollo de habilidades sociales de los estudiantes del grupo experimental en comparación con el grupo control, del nivel de secundaria de la Institución Educativa Fuerza Aérea del Perú “José Quiñones”, La Molina, 2014. Se desarrolló una investigación de tipo aplicativo, empleando un diseño cuasi-experimental, se midió con el instrumento: La lista de evaluación de habilidades sociales – Minsa (L.E.H.S.) con pre y post prueba en la muestra del grupo control de 22 estudiantes y el grupo experimental de 22 estudiantes, del segundo grado de educación secundaria de la I.E.FAP. “José Quiñones” de la Molina, con una población de 597 estudiantes del nivel secundaria. Los resultados obtenidos mostraron en primera instancia, que no existían diferencias significativas entre los componentes de las habilidades sociales de los estudiantes del grupo control y experimental en el pre test (Lista de evaluación de habilidades sociales), sin embargo, luego de aplicar el programa de habilidades sociales para adolescentes escolares, los resultados del post test, sí mostraron diferencias significativas entre los componentes de las habilidades sociales del grupo control frente al del grupo experimental (Lista de evaluación de habilidades sociales), mostrando un significativo desarrollo en los estudiantes del grupo experimental, sobre todo en las en las dimensiones de comunicación, asertividad y toma de decisiones, en comparación con el grupo control; por lo que se concluye que el manual de habilidades sociales en adolescentes escolares del MINSA influye positivamente sobre el desarrollo de habilidades sociales en los estudiantes del segundo grado de secundaria en la Institución Educativa Fuerza Aérea del Perú “José Quiñones” de La Molina

    Einsatz bioanalytischer Systeme bei der industriellen Produktion von Pharmaaminosäuren

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    Aminosäuren finden in den verschiedensten Bereichen vielfältigen Einsatz. Hauptanwendungsgebiete sind die Nahrungsmittel- (50%), Futtermittel (30%)- und pharmazeutische (20%) Industrie. In der pharmazeutischen Industrie werden Aminosäuren höchster Reinheit benötigt. Ein sehr wichtiges Beispiel ist die Verwendung für prä- oder postoperative parenterale Ernährung. In der Kosmetikindustrie dienen Aminosäuren als Ausgangssubstanzen für die Herstellung hochwertiger Hautcremes. Für die Gewinnung von Aminosäuren stehen diverse großtechnische Verfahren zur Verfügung: die Extraktion aus nachwachsenden Rohstoffen, die fermentative Gewinnung, die chemische Synthese und die Biotransformation. Über diese Verfahren wird eine geschätzte Jahresproduktion von weltweit ca. 3. Mrd. Tonnen hergestellt. Bei der AMINO GmbH werden Aminosäuren für den pharmazeutischen Markt aus nachwachsenden Rohstoffen wie Zuckerrübenmelasse über chromatographische Verfahren und Biotransformationen (enzymatische Katalyse) gewonnen. Hierbei ist eine On-line-Prozesskontrolle unabdingbar. Durch die optimierte Kontrolle und Führung des Bioprozesses können Ressourcen eingespart werden. Daraus ergeben sich direkt Umweltentlastungen und Kostenersparnisse. Mit den bisher erzielten Ergebnissen kann eine 20% höhere Produktkonzentration erreicht werden. Dieses entspricht – gerechnet auf die nachfolgenden Aufarbeitungsschritte – einer Ersparnis von 200 bis 300 t Dampf pro Jahr (20% der Produkt spezifischen Energiekosten). Ebenfalls einsparen lassen sich bis zu 2000 m3 Abwasser (entsprechend 0,4 t COD) pro Jahr. Letztendlich ist es das Ziel mit Hilfe der bioanalytischen Verfahren pro Jahr 3,5 t Serin und 0,5 t Indol durch eine 30% höhere Produktausbeute einsparen zu können. Es zeigt sich somit, dass der Einsatz moderner bioanalytischer Verfahren wie der 2-D-Fluoreszenzspektroskopie durchaus zu einer Verbesserung der ökonomischen als auch der ökologischen Faktoren eines industriellen Prozesses führen kann

    Synchrotron X-ray diffraction experiments with a prototype hybrid pixel detector

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    International audienceA prototype X-ray pixel area detector (XPAD3.1) has been used for X-ray diffraction experiments with synchrotron radiation. The characteristics of this detector are very attractive in terms of fast readout time, high dynamic range and high signal-to-noise ratio. The prototype XPAD3.1 enabled various diffraction experiments to be performed at different energies, sample-to-detector distances and detector angles with respect to the direct beam, yet it was necessary to perform corrections on the diffraction images according to the type of experiment. This paper is focused on calibration and correction procedures to obtain high-quality scientific results specifically developed in the context of three different experiments, namely mechanical characterization of nanostructured multilayers, elastic-plastic deformation of duplex steel and growth of carbon nanotubes

    Middleborns disadvantaged? testing birth-order effects on fitness in pre-industrial finns

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    Parental investment is a limited resource for which offspring compete in order to increase their own survival and reproductive success. However, parents might be selected to influence the outcome of sibling competition through differential investment. While evidence for this is widespread in egg-laying species, whether or not this may also be the case in viviparous species is more difficult to determine. We use pre-industrial Finns as our model system and an equal investment model as our null hypothesis, which predicts that (all else being equal) middleborns should be disadvantaged through competition. We found no overall evidence to suggest that middleborns in a family are disadvantaged in terms of their survival, age at first reproduction or lifetime reproductive success. However, when considering birth-order only among same-sexed siblings, first-, middle-and lastborn sons significantly differed in the number of offspring they were able to rear to adulthood, although there was no similar effect among females. Middleborn sons appeared to produce significantly less offspring than first-or lastborn sons, but they did not significantly differ from lastborn sons in the number of offspring reared to adulthood. Our results thus show that taking sex differences into account is important when modelling birth-order effects. We found clear evidence of firstborn sons being advantaged over other sons in the family, and over firstborn daughters. Therefore, our results suggest that parents invest differentially in their offspring in order to both preferentially favour particular offspring or reduce offspring inequalities arising from sibling competition

    Proteomic Analysis of Grape Berry Cell Cultures Reveals that Developmentally Regulated Ripening Related Processes Can Be Studied Using Cultured Cells

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    The original publication is available at http:/www.plosone.orgBackground: This work describes a proteomics profiling method, optimized and applied to berry cell suspensions to evaluate organ-specific cultures as a platform to study grape berry ripening. Variations in berry ripening within a cluster(s) on a vine and in a vineyard are a major impediment towards complete understanding of the functional processes that control ripening, specifically when a characterized and homogenous sample is required. Berry cell suspensions could overcome some of these problems, but their suitability as a model system for berry development and ripening needs to be established first. Methodology/Principal Findings: In this study we report on the proteomic evaluation of the cytosolic proteins obtained from synchronized cell suspension cultures that were established from callus lines originating from green, véraison and ripe Vitis vinifera berry explants. The proteins were separated using liquid phase IEF in a Microrotofor cell and SDS PAGE. This method proved superior to gel-based 2DE. Principal component analysis confirmed that biological and technical repeats grouped tightly and importantly, showed that the proteomes of berry cultures originating from the different growth/ripening stages were distinct. A total of twenty six common bands were selected after band matching between different growth stages and twenty two of these bands were positively identified. Thirty two % of the identified proteins are currently annotated as hypothetical. The differential expression profile of the identified proteins, when compared with published literature on grape berry ripening, suggested common trends in terms of relative abundance in the different developmental stages between real berries and cell suspensions. Conclusions: The advantages of having suspension cultures that accurately mimic specific developmental stages are profound and could significantly contribute to the study of the intricate regulatory and signaling networks responsible for berry development and ripening. © 2011 Sharathchandra et al.Publishers' Versio

    Electroporation-Induced Electrosensitization

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    BACKGROUND: Electroporation is a method of disrupting the integrity of cell membrane by electric pulses (EPs). Electrical modeling is widely employed to explain and study electroporation, but even most advanced models show limited predictive power. No studies have accounted for the biological consequences of electroporation as a factor that alters the cell's susceptibility to forthcoming EPs. METHODOLOGY/PRINCIPAL FINDINGS: We focused first on the role of EP rate for membrane permeabilization and lethal effects in mammalian cells. The rate was varied from 0.001 to 2,000 Hz while keeping other parameters constant (2 to 3,750 pulses of 60-ns to 9-µs duration, 1.8 to 13.3 kV/cm). The efficiency of all EP treatments was minimal at high rates and started to increase gradually when the rate decreased below a certain value. Although this value ranged widely (0.1-500 Hz), it always corresponded to the overall treatment duration near 10 s. We further found that longer exposures were more efficient irrespective of the EP rate, and that splitting a high-rate EP train in two fractions with 1-5 min delay enhanced the effects severalfold. CONCLUSIONS/SIGNIFICANCE: For varied experimental conditions, EPs triggered a delayed and gradual sensitization to EPs. When a portion of a multi-pulse exposure was delivered to already sensitized cells, the overall effect markedly increased. Because of the sensitization, the lethality in EP-treated cells could be increased from 0 to 90% simply by increasing the exposure duration, or the exposure dose could be reduced twofold without reducing the effect. Many applications of electroporation can benefit from accounting for sensitization, by organizing the exposure either to maximize sensitization (e.g., for sterilization) or, for other applications, to completely or partially avoid it. In particular, harmful side effects of electroporation-based therapies (electrochemotherapy, gene therapies, tumor ablation) include convulsions, pain, heart fibrillation, and thermal damage. Sensitization can potentially be employed to reduce these side effects while preserving or increasing therapeutic efficiency

    Linkage of Type I Interferon Activity and TNF-Alpha Levels in Serum with Sarcoidosis Manifestations and Ancestry

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    BACKGROUND: Both type I interferon (IFN), also known as IFN-α and tumor necrosis factor alpha (TNF-α) have been implicated in the pathogenesis of sarcoidosis. We investigated serum levels of these cytokines in a large multi-ancestral sarcoidosis population to determine correlations between cytokine levels and disease phenotypes. METHODS: We studied serum samples from 98 patients with sarcoidosis, including 71 patients of African-American ancestry and 27 patients of European-American ancestry. Serum type I IFN was measured using a sensitive reporter cell assay and serum TNF-α was measured using a commercial ELISA kit. Clinical data including presence or absence of neurologic, cardiac, and severe pulmonary manifestations of sarcoidosis were abstracted from medical records. Twenty age-matched non-autoimmune controls were also studied from each ancestral background. Differences in cytokine levels between groups were analyzed with Mann-Whitney U test, and correlations were assessed using Spearman's rho. Multivariate logistic regression models were used to detect associations between cytokines and clinical manifestations. RESULTS: Significant differences in cytokine levels were observed between African- and European-American patients with sarcoidosis. In African-Americans, serum TNF-α levels were significantly higher relative to matched controls (P = 0.039), and patients with neurologic disease had significantly higher TNF-α than patients lacking this manifestation (P = 0.022). In European-Americans, serum type I IFN activity was higher in sarcoidosis cases as compared to matched controls, and patients with extra-pulmonary disease represented a high serum IFN subgroup (P = 0.0032). None of the associations observed were shared between the two ancestral groups. CONCLUSIONS: Our data indicate that significant associations between serum levels of TNF-α and type I IFN and clinical manifestations exist in a sarcoidosis cohort that differ significantly by self-reported ancestry. In each ancestral background, the cytokine elevated in patients with sarcoidosis was also associated with a particular disease phenotype. These findings may relate to ancestral differences in the molecular pathogenesis of this heterogeneous disease
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