39 research outputs found

    Multiplicities of charged pions and unidentified charged hadrons from deep-inelastic scattering of muons off an isoscalar target

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    Multiplicities of charged pions and unidentified hadrons produced in deep-inelastic scattering were measured in bins of the Bjorken scaling variable xx, the relative virtual-photon energy yy and the relative hadron energy zz. Data were obtained by the COMPASS Collaboration using a 160 GeV muon beam and an isoscalar target (6^6LiD). They cover the kinematic domain in the photon virtuality Q2Q^2 > 1(GeV/c)2)^2, 0.004<x<0.40.004 < x < 0.4, 0.2<z<0.850.2 < z < 0.85 and 0.1<y<0.70.1 < y < 0.7. In addition, a leading-order pQCD analysis was performed using the pion multiplicity results to extract quark fragmentation functions

    Structure of Metaphase Chromosomes: A Role for Effects of Macromolecular Crowding

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    In metaphase chromosomes, chromatin is compacted to a concentration of several hundred mg/ml by mechanisms which remain elusive. Effects mediated by the ionic environment are considered most frequently because mono- and di-valent cations cause polynucleosome chains to form compact ∌30-nm diameter fibres in vitro, but this conformation is not detected in chromosomes in situ. A further unconsidered factor is predicted to influence the compaction of chromosomes, namely the forces which arise from crowding by macromolecules in the surrounding cytoplasm whose measured concentration is 100–200 mg/ml. To mimic these conditions, chromosomes were released from mitotic CHO cells in solutions containing an inert volume-occupying macromolecule (8 kDa polyethylene glycol, 10.5 kDa dextran, or 70 kDa Ficoll) in 100 ”M K-Hepes buffer, with contaminating cations at only low micromolar concentrations. Optical and electron microscopy showed that these chromosomes conserved their characteristic structure and compaction, and their volume varied inversely with the concentration of a crowding macromolecule. They showed a canonical nucleosomal structure and contained the characteristic proteins topoisomerase IIα and the condensin subunit SMC2. These observations, together with evidence that the cytoplasm is crowded in vivo, suggest that macromolecular crowding effects should be considered a significant and perhaps major factor in compacting chromosomes. This model may explain why ∌30-nm fibres characteristic of cation-mediated compaction are not seen in chromosomes in situ. Considering that crowding by cytoplasmic macromolecules maintains the compaction of bacterial chromosomes and has been proposed to form the liquid crystalline chromosomes of dinoflagellates, a crowded environment may be an essential characteristic of all genomes

    Multiplicities of charged kaons from deep-inelastic muon scattering off an isoscalar target

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    Precise measurements of charged-kaon multiplicities in deep inelastic scattering were performed. The results are presented in three-dimensional bins of the Bjorken scaling variable x, the relative virtual-photon energy y, and the fraction z of the virtual-photon energy carried by the produced hadron. The data were obtained by the COMPASS Collaboration by scattering 160 GeV muons off an isoscalar 6LiD target. They cover the kinematic domain View the MathML source in the photon virtuality, 0.0045 GeV/c2 in the invariant mass of the hadronic system. The results from the sum of the z -integrated K+ and K 12 multiplicities at high x point to a value of the non-strange quark fragmentation function larger than obtained by the earlier DSS fit

    Guidelines for the use and interpretation of assays for monitoring autophagy (4th edition)1.

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    In 2008, we published the first set of guidelines for standardizing research in autophagy. Since then, this topic has received increasing attention, and many scientists have entered the field. Our knowledge base and relevant new technologies have also been expanding. Thus, it is important to formulate on a regular basis updated guidelines for monitoring autophagy in different organisms. Despite numerous reviews, there continues to be confusion regarding acceptable methods to evaluate autophagy, especially in multicellular eukaryotes. Here, we present a set of guidelines for investigators to select and interpret methods to examine autophagy and related processes, and for reviewers to provide realistic and reasonable critiques of reports that are focused on these processes. These guidelines are not meant to be a dogmatic set of rules, because the appropriateness of any assay largely depends on the question being asked and the system being used. Moreover, no individual assay is perfect for every situation, calling for the use of multiple techniques to properly monitor autophagy in each experimental setting. Finally, several core components of the autophagy machinery have been implicated in distinct autophagic processes (canonical and noncanonical autophagy), implying that genetic approaches to block autophagy should rely on targeting two or more autophagy-related genes that ideally participate in distinct steps of the pathway. Along similar lines, because multiple proteins involved in autophagy also regulate other cellular pathways including apoptosis, not all of them can be used as a specific marker for bona fide autophagic responses. Here, we critically discuss current methods of assessing autophagy and the information they can, or cannot, provide. Our ultimate goal is to encourage intellectual and technical innovation in the field

    Microcurrent application as analgesic treatment in venous ulcers: a pilot study La aplicaciĂłn de microcorriente como tratamiento en las Ășlceras venosas: un estudio piloto Aplicação da microcorrente como recurso para tratamento de Ășlceras venosas: um estudo piloto

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    This study aimed to evaluate the effect of microcurrent electrical stimulation on pain and area of venous ulcers. In a pilot study for a single-blind controlled clinical trial, carried out at an outpatient clinic during four weeks, 14 subjects with venous ulcers (mean age 62±9 years) were divided in two groups: microcurrent (n=8) and control group (n=6). Pain (by Visual Analogue Scale) and the ulcer area were measured by planimetry. There was a significant difference between the two groups with respect to pain (microcurrent group from 8.5 (6.5-9.75) to 3.5 (1-4.75) and control group from 7.5 (5.75-10) to 8.5 (5.5-10), p<0.01). Non-significant changes were found with respect to ulcer area (planimetry by graph paper, p=0.41 and by Image JÂź, p=0.41). In conclusion, the application of microcurrent improves the pain of patients with venous ulcers (ClinicalTrials.gov: NCT01372020).<br>Este estudio objetivĂł evaluar el efecto de la estimulaciĂłn elĂ©ctrica por microcorriente sobre el dolor y el ĂĄrea de superficie de Ășlceras venosas. En un estudio piloto para un ensayo clĂ­nico controlado simple ciego, realizado en una clĂ­nica durante 4 semanas, se dividieron 14 individuos (62±9 años de edad) en dos grupos: grupo microcorriente (n=8) y grupo control (n=6). Se evaluaron el dolor (por medio de la Escala Visual AnalĂłgica) y el ĂĄrea de superficie de la Ășlcera por medio de la PlanimetrĂ­a. Hubo diferencia significativa entre los dos grupos con relaciĂłn al dolor (grupo de microcorriente de 8,5 (6,5-9,75) para 3,5 (1-4,75) y grupo control de 7,5 (5,75-10) para 8,5 (5,5-10), p<0,01)). No se verificĂł una diferencia significativa relacionada al ĂĄrea de superficie de la Ășlcera (PlanimetrĂ­a con papel vegetal, p=0,41 y por el software Image JÂź, p=0,41). Se concluye que la aplicaciĂłn de microcorriente mejora el cuadro ĂĄlgico de individuos con Ășlceras venosas. Registro ClinicalTrials.gov: NCT01372020.<br>O objetivo neste estudo foi avaliar o efeito da estimulação elĂ©trica, por microcorrente, sobre a dor e a ĂĄrea de superfĂ­cie de Ășlceras venosas. Em estudo-piloto para um ensaio clĂ­nico controlado simples-cego, realizado em uma clĂ­nica durante 4 semanas, dividiram-se 14 indivĂ­duos (62±9 anos de idade) em dois grupos: grupo microcorrente (n=8) e grupo-controle (n=6). Avaliaram-se a dor (por meio da Escala Visual AnalĂłgica) e a ĂĄrea de superfĂ­cie da Ășlcera por meio da Planimetria. Houve diferença significativa entre os dois grupos em relação Ă  dor (grupo de microcorrente de 8,5 (6,5-9,75) para 3,5 (1-4,75) e grupo-controle de 7,5 (5,75-10) para 8,5 (5,5-10), p<0,01)). NĂŁo se verificou diferença significativa relacionada Ă  ĂĄrea de superfĂ­cie da Ășlcera (Planimetria com papel vegetal, p=0,41 e pelo software Image JÂź, p=0,41). Conclui-se que a aplicação de microcorrente melhora o quadro ĂĄlgico de indivĂ­duos com Ășlceras venosas. Registro ClinicalTrials.gov: NCT01372020

    Realizing a SnO2-based ultraviolet light-emitting diode via breaking the dipole-forbidden rule

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    Although many oxide semiconductors possess wide bandgaps in the ultraviolet (UV) regime, currently the majority of them cannot efficiently emit UV light because the band-edge optical transition is forbidden in a perfect lattice as a result of the symmetry of the band-edge states. This quantum mechanical rule severely constrains the optical applications of wide-bandgap oxides, which is also the reason why so few oxides enjoy the success of ZnO. Here, using SnO2 as an example, we demonstrate both theoretically and experimentally that UV photoluminescence and electroluminescence can be recovered and enhanced in wide-bandgap oxide thin films with ‘forbidden’ energy gaps by engineering their nanocrystalline structures. In our experiments, the tailored low-temperature annealing process results in a hybrid structure containing SnO2 nanocrystals in an amorphous matrix, and UV emission is observed in such hybrid SnO2 thin films, indicating that the quantum mechanical dipole-forbidden rule has been effectively overcome. Using this approach, we demonstrate the first prototypical electrically pumped UV-light-emitting diode based on nanostructured SnO2 thin films.Published versio
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