3,010 research outputs found
Embioptera (Insecta) from Brazil: New species and a taxonomic update
Eight new species of Embioptera from Brazil are described, diagnosed, and illustrated. For Anisembiidae: Chelicerca achilata Szumik, Pereyra & Juárez, sp. nov.; Saussurembia borba Szumik, Pereyra & Juárez, sp. nov. For Archembiidae: Archembia oruma Szumik, sp. nov.; Embolyntha oriximina Szumik, Pereyra & Juárez, sp. nov.; Pararhagadochir bonita Szumik, Pereyra & Juárez, sp. nov., Pararhagadochir marielleae Szumik, Pereyra & Juárez, sp. nov.; Pararhagadochir para Szumik, Pereyra & Juárez, sp. nov. For Clothodidae: Chromatoclothoda langa Szumik, Pereyra & Juárez, sp. nov. To clarify the higher classification of the Order and to have an accurate taxonomy, a species catalog and introduction to the four families present in Brazil is also detailed, including phylogenetic relationships, taxonomic actions, composition, distributions, and records maps. Herein, several taxonomic acts are proposed: (1) the synonymy of Chelicerca Ross (= Dactylocerca Ross confirmed junior synonym; = Schizembia Ross syn nov.; = Pelorembia Ross, confirmed junior synonym; = Cryptembia Ross, syn. nov.) and Saussurembia Davis (= Stenembia Ross, syn. nov.). (2) new status and delimitation for family Archembiidae Ross, stat. rev.; subfamily Archembiinae Ross, stat. rev.; subfamily Pachylembiinae stat. rev.; subfamily Scelembiinae stat. rev., and their genera included. (3) Diradius unicolor (Ross) (Teratembiidae) comb. nov., and (4) new locality records for previously cited species in the region.Fil: Szumik, Claudia Adriana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico - Tucumán. Unidad Ejecutora Lillo; ArgentinaFil: Pereyra, Verónica. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico - Tucumán. Unidad Ejecutora Lillo; ArgentinaFil: Goloboff Szumik, Victoria E.. Universidad Nacional de Tucumán. Facultad de Ciencias Naturales e Instituto Miguel Lillo; ArgentinaFil: Costa Pinto, Paula Jéssica. Ministério da Ciência, Tecnologia, Inovações. Instituto Nacional de Pesquisas da Amazônia; Brasil. Universidade Federal do Paraná; BrasilFil: Juárez, María Laura. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico - Tucumán. Unidad Ejecutora Lillo; Argentin
Presence of osteoclast-like multinucleated giant cells in the bone and nonostotic lesions of Langerhans cell histiocytosis
Langerhans cell histiocytosis (LCH) is a disease that can involve one or multiple organ systems characterized by an accumulation of CD1a+ Langerhans-like cells as well as several other myeloid cell types. The precise origin and role of one of these populations, the multinucleated giant cell (MGC), in this disease remains unknown. This work shows that in three different lesional tissues, bone, skin, and lymph node, the MGCs expressed the characteristic osteoclast markers, tartrate-resistant acid phosphatase and vitronectin receptor, as well as the enzymes cathepsin K and matrix metalloproteinase-9. Although, in bone lesions, the osteoclast-like MGCs were only CD68+, in the nonostotic sites, they coexpressed CD1a. The presence of osteoclast-like MGCs may be explained by the production of osteoclast-inducing cytokines such as receptor activator of nuclear factor κB ligand and macrophage colony-stimulating factor by both the CD1a+ LCH cells and T cells in these lesions. As osteoclast-derived enzymes play a major role in tissue destruction, the osteoclast-like nature of MGCs in all LCH lesions makes them a potential target for the treatment of this disease
Front microrheology of the non-Newtonian behavior of blood: scaling theory of erythrocyte aggregation by aging
We introduce a new framework to study the non-Newtonian behaviour of fluids at the microscale based on the analysis of front advancement. We apply this methodology to study the non-linear rheology of blood in microchannels. We carry out experiments in which the non-linear viscosity of blood samples is quantified at different haematocrits and ages. Under these conditions, blood exhibits a power-law dependence on the shear rate. In order to analyse our experimental data, we put forward a scaling theory which allows us to define an adhesion scaling number. This theory yields a scaling behaviour of the viscosity expressed as a function of the adhesion capillary number. By applying this scaling theory to samples of different ages, we are able to quantify how the characteristic adhesion energy varies as time progresses. This connection between microscopic and mesoscopic properties allows us to estimate quantitatively the change in the cell-cell adhesion energies as the sample age
Alteraciones morfológicas en las mitocondrias en la piel de enfermos con esclerosis lateral amiotrófica esporádica
Mitochondrial dysfunction has been reported in the central nervous system, hepatocytes and peripheral blood lymphocytes from patients with sporadic amyotrophic lateral sclerosis (SALS). However, the status of skin mitochondria has not been reported, in spite of the fact that SALS patients present skin abnormalities. The objective of the present study was to compare mitochondrial ultrastructural parameters in keratinocytes from patients with SALS and healthy controls.Existen alteraciones en la función mitocondrial en el sistema nervioso central, en hepatocitos y en linfocitos de sangre periférica en SALS. Aunque, no se ha estudiado si existen cambios estructurales en las mitocondrias de la piel. Nuestro objetivo fue comparar la ultraestructura de mitocondrias en queratinocitos de enfermos con SALS con la de controles sanos.Fil: Rodríguez, Gabriel E.. Gobierno de la Ciudad de Buenos Aires. Hospital General de Agudos "Ramos Mejía"; Argentina. Universidad de Buenos Aires. Facultad de Medicina; ArgentinaFil: Gonzalez Deniselle, Maria Claudia. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental. Fundación de Instituto de Biología y Medicina Experimental. Instituto de Biología y Medicina Experimental; Argentina. Universidad de Buenos Aires. Facultad de Medicina. Departamento de Bioquímica Humana; ArgentinaFil: Gargiulo Monachelli, Gisella Mariana. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental. Fundación de Instituto de Biología y Medicina Experimental. Instituto de Biología y Medicina Experimental; Argentina. Gobierno de la Ciudad de Buenos Aires. Hospital General de Agudos "Ramos Mejía"; ArgentinaFil: Lopez Costa, Juan J.. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Biología Celular y Neurociencia "Prof. Eduardo de Robertis". Universidad de Buenos Aires. Facultad de Medicina. Instituto de Biología Celular y Neurociencia; ArgentinaFil: De Nicola A. F.. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental. Fundación de Instituto de Biología y Medicina Experimental. Instituto de Biología y Medicina Experimental; Argentina. Universidad de Buenos Aires. Facultad de Medicina. Departamento de Bioquímica Humana; ArgentinaFil: Sica, Roberto Ernesto Pedro. Universidad de Buenos Aires. Facultad de Medicina; Argentin
Feasibility Study for an Aquatic Ecosystem Earth Observing System Version 1.2.
International audienceMany Earth observing sensors have been designed, built and launched with primary objectives of either terrestrial or ocean remote sensing applications. Often the data from these sensors are also used for freshwater, estuarine and coastal water quality observations, bathymetry and benthic mapping. However, such land and ocean specific sensors are not designed for these complex aquatic environments and consequently are not likely to perform as well as a dedicated sensor would. As a CEOS action, CSIRO and DLR have taken the lead on a feasibility assessment to determine the benefits and technological difficulties of designing an Earth observing satellite mission focused on the biogeochemistry of inland, estuarine, deltaic and near coastal waters as well as mapping macrophytes, macro-algae, sea grasses and coral reefs. These environments need higher spatial resolution than current and planned ocean colour sensors offer and need higher spectral resolution than current and planned land Earth observing sensors offer (with the exception of several R&D type imaging spectrometry satellite missions). The results indicate that a dedicated sensor of (non-oceanic) aquatic ecosystems could be a multispectral sensor with ~26 bands in the 380-780 nm wavelength range for retrieving the aquatic ecosystem variables as well as another 15 spectral bands between 360-380 nm and 780-1400 nm for removing atmospheric and air-water interface effects. These requirements are very close to defining an imaging spectrometer with spectral bands between 360 and 1000 nm (suitable for Si based detectors), possibly augmented by a SWIR imaging spectrometer. In that case the spectral bands would ideally have 5 nm spacing and Full Width Half Maximum (FWHM), although it may be necessary to go to 8 nm wide spectral bands (between 380 to 780nm where the fine spectral features occur -mainly due to photosynthetic or accessory pigments) to obtain enough signal to noise. The spatial resolution of such a global mapping mission would be between ~17 and ~33 m enabling imaging of the vast majority of water bodies (lakes, reservoirs, lagoons, estuaries etc.) larger than 0.2 ha and ~25% of river reaches globally (at ~17 m resolution) whilst maintaining sufficient radiometric resolution
Human glioblastoma multiforme: p53 reactivation by a novel MDM2 inhibitor
Cancer development and chemo-resistance are often due to impaired functioning of the p53 tumor suppressor through genetic mutation or sequestration by other proteins. In glioblastoma multiforme (GBM), p53 availability is frequently reduced because it binds to the Murine Double Minute-2 (MDM2) oncoprotein, which accumulates at high concentrations in tumor cells. The use of MDM2 inhibitors that interfere with the binding of p53 and MDM2 has become a valid approach to inhibit cell growth in a number of cancers; however little is known about the efficacy of these inhibitors in GBM. We report that a new small-molecule inhibitor of MDM2 with a spirooxoindolepyrrolidine core structure, named ISA27, effectively reactivated p53 function and inhibited human GBM cell growth in vitro by inducing cell cycle arrest and apoptosis. In immunoincompetent BALB/c nude mice bearing a human GBM xenograft, the administration of ISA27 in vivo activated p53, inhibited cell proliferation and induced apoptosis in tumor tissue. Significantly, ISA27 was non-toxic in an in vitro normal human cell model and an in vivo mouse model. ISA27 administration in combination with temozolomide (TMZ) produced a synergistic inhibitory effect on GBM cell viability in vitro, suggesting the possibility of lowering the dose of TMZ used in the treatment of GBM. In conclusion, our data show that ISA27 releases the powerful antitumor capacities of p53 in GBM cells. The use of this MDM2 inhibitor could become a novel therapy for the treatment of GBM patients
FORMAÇÃO INICIAL DOCENTE E ESTÁGIO CURRICULAR SUPERVISIONADO NA LICENCIATURA EM QUÍMICA: PERCEPÇÕES E EXPERIÊNCIAS DE ALUNOS CONCLUINTES
This study aims to analyze the perception of students about the Supervised Curricular Internship in the Teacher formation course in Chemistry, based on their experiences, and discuss the internship as a theoretical-practical space and for reflection on teaching. Based on the reflection on the internship the criticism of the reductionist understanding of this as the time of practice, a qualitative-descriptive study was developed, having as a locus the teacher formation course in Chemistry of a federal institution of higher education in the interior of the state of Ceará, Brazil, with the participation of three undergraduate students who answered five subjective questions about the internship, the answers being analyzed from their meanings and senses. The results indicate in the investigated context the predominance of internships as bureaucratic practice, imitation of models distant from the reflexive-investigative perspective, as well as the critical view of the undergraduate students about the limits of this formative perspective. However, even in the face of the adversities experienced during the internship, students perceive it as an important formative moment for their initial formation.El estudio tiene como objetivo analizar la percepción de los estudiantes de pregrado sobre la Pasantía Curricular Supervisada en la Licenciatura de Química a partir de sus experiencias, y discutir la pasantía como espacio teórico-práctico y de reflexión sobre la docencia. A partir de la reflexión sobre la pasantía y la crítica a la comprensión reduccionista de esta como el tiempo de la práctica, se desarrolló un estudio cualitativo-descriptivo, teniendo como locus la Licenciatura en Química de una institución federal de educación superior en el interior de Ceará, con la participación de tres estudiantes de pregrado que respondieron a cinco preguntas subjetivas sobre la pasantía, analizándose las respuestas desde sus significados y sentidos. Los resultados indican en el contexto investigado el predominio de las pasantías como práctica burocrática, imitación de modelos y distante de la perspectiva reflexiva-investigadora, así como la mirada crítica de los estudiantes sobre los límites de esta perspectiva formativa. Sin embargo, incluso ante las adversidades vividas durante la pasantía, los estudiantes lo perciben como un momento importante para su formación inicial.O estudo objetiva analisar a percepção de licenciandos sobre o Estágio Curricular Supervisionado na Licenciatura em Química a partir de suas experiências, e discutir o estágio como um espaço teórico-prático e de reflexão sobre a docência. Partindo da reflexão sobre o estágio e a crítica à compreensão reducionista deste como a hora da prática, foi desenvolvido um estudo qualitativo-descritivo, tendo como lócus o curso de Licenciatura em Química de uma instituição federal de ensino superior no interior do Ceará, com a participação de três licenciandos que responderam a cinco perguntas subjetivas sobre o estágio, sendo as respostas analisadas a partir de suas significações e sentidos. Os resultados indicam no contexto investigado a predominância de estágios como prática burocrática, imitação de modelos e distante da perspectiva reflexivo-investigativa, assim como a visão crítica dos licenciandos acerca dos limites dessa perspectiva formativa. Contudo, mesmo diante das adversidades vivenciadas ao longo do estágio, os alunos o percebem como um momento importante para sua formação inicial.
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