1,667 research outputs found

    Generalizing Planck's distribution by using the Carati-Galgani model of molecular collisions

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    Classical systems of coupled harmonic oscillators are studied using the Carati-Galgani model. We investigate the consequences for Einstein's conjecture by considering that the exchanges of energy, in molecular collisions, follows the L\'evy type statistics. We develop a generalization of Planck's distribution admitting that there are analogous relations in the equilibrium quantum statistical mechanics of the relations found using the nonequilibrium classical statistical mechanics approach. The generalization of Planck's law based on the nonextensive statistical mechanics formalism is compatible with the our analysis.Comment: 10 pages, 3 figure

    A small series of pole sport injuries

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    Pole sport is a relatively new athletic sport that is gaining increasing popularity and for which national and international championships are held. It evolved from pole dance and harbours the risk of falls from heights of up to three metres. Currently, no studies on pole sport injuries are available. This is the first description of a small series of five pole sport injuries. A retrospective review of the case histories and radiological findings was performed, and in addition, a follow-up interview was carried out. All the patients were female and had a mean age of 27.2 years. Most injuries were located in the head, neck or spine. The use of proper training equipment like landing mats and grip aids could probably reduce accidents

    Lithologierekonstruktion von submarinen Einheiten des Mauna Kea Vulkans mit bohrlochgeophysikalischen Messungen der magnetischen Suszeptibilität, HSDP Bohrung, Hawai’i

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    Als Teil des International Continental Drilling Projects (ICDP), wurde von März bis September 1999 im Rahmen des Hawai’i Scientific Drilling Projects (HSDP) die etwa 3109m tiefe HSDP-2 Bohrung in der Nähe von Hilo auf Big Island, Hawai’i niedergebracht. Die mit einem Durchmesser von 98mm (3.8500) durchgehend gekernte Bohrung, durchteuft sowohl die subaerischen Einheiten des Mauna Loa, als auch die darunter liegenden submarinen Laven des Mauna Kea. Ab etwa 1080m Teufe wurden die jüngsten, während der Entwicklung dieses Vulkans abgelagerten submarinen Laven erbohrt. Die Verteilung von Hyaloklastiten, Pillowlaven, massiver Intrusiva sowie sedimentärer Ablagerungen, wurde durch die lithologische Beschreibung des durchgehend geförderten Kernprofils von DePaolo et al. (1999) aufgenommen. Verschiedene Autoren, wie z.B. Bücker et al. (1999) oder Helm-Clark et al. (2004) haben bereits gezeigt, dass sich Messungen der natürlichen Gammastrahlung (GR), die üblicherweise sehr gut zur lithologischen Einteilung von Gesteinen herangezogen werden können, in vergleichbaren Bohrungen nur sehr bedingt zur primären Unterscheidung basaltischer Gesteinseinheiten eignen. Dies ist vor allem auf die sehr geringe Variation des K-, U- und Th-Gehalts der Basalte zurückzuführen. Daher wurden von der Operational Support Group (OSG) des GFZ-Potsdam im November 2002 bohrlochgeophysikalische Messungen in dem 98mm Bohrloch in einem Bereich von etwa 1830 bis 2615m durchgeführt. Diese wurden speziell zum Test einer Bohrlochsonde zur Messung der magnetischen Suszeptibilität (MS) im Rahmen des DFG-Projektes Wa 1015/4 angesetzt. Dazu wurde die MSdH-2 Sonde der OSG, hergestellt von der Fa. Antares GmbH (Stuhr, Germany) eingesetzt.conferenc

    Structure of the ribosome post-recycling complex probed by chemical cross-linking and mass spectrometry

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    Ribosome recycling orchestrated by the ATP binding cassette (ABC) protein ABCE1 can be considered as the final-or the first-step within the cyclic process of protein synthesis, connecting translation termination and mRNA surveillance with re-initiation. An ATP-dependent tweezer-like motion of the nucleotide-binding domains in ABCE1 transfers mechanical energy to the ribosome and tears the ribosome subunits apart. The post-recycling complex (PRC) then re-initiates mRNA translation. Here, we probed the so far unknown architecture of the 1-MDa PRC (40S/30S.ABCE1) by chemical cross-linking and mass spectrometry (XL-MS). Our study reveals ABCE1 bound to the translational factor-binding (GTPase) site with multiple cross-link contacts of the helix-loop-helix motif to the S24e ribosomal protein. Cross-linking of the FeS cluster domain to the ribosomal protein S12 substantiates an extreme lever-arm movement of the FeS cluster domain during ribosome recycling. We were thus able to reconstitute and structurally analyse a key complex in the translational cycle, resembling the link between translation initiation and ribosome recycling

    Morphology of Endothelial Cells from Different Regions of the Swine Cornea

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    Background: The corneal endothelium is a monolayer of polygonal cells which constitute the last layer of the cornea. The integrity of this layer is critical to cornea transparency. The characterization of normal corneal endothelial morphology is important not only to clinical evaluation but also to selection of areas of the cornea with better quality to be employed as donor tissue. The aim of the present study was to evaluate the morphology of endothelial cells from different regions of the swine cornea after alizarin red staining using optical microscopy.Materials, Methods & Results: Twenty-four healthy eyes from 12 swine Large White breed, with 14-month-old, males or females obtained from a licensed Brazilian commercial slaughterhouse were studied. Immediately after humane slaughter, the eyes were enucleated and submitted to ophthalmic examination. Eyes with signs of diseases of the anterior segment were excluded. The cornea, with 3 mm of the sclera, was removed and placed on a glass microscope slide with the endothelial side up. Four radial incisions were made in the periphery of the cornea to better accommodate the cornea on the microscope slide. Alizarin red was diluted in isotonic solution (0.2 g/100 mL) and the pH was adjusted to 4.2 with hydrochloric acid. Three drops of alizarin red were placed on the corneal endothelium. After 90 s, the dye was removed from the cornea with balanced saline solution. The corneal endothelium was examined and photographed using an optical microscope. All evaluations were performed by the same investigator. Photomicrographs were taken of central, superior, inferior, nasal and temporal corneal areas. Parameter studied included endothelial cell morphology. For the statistical analysis, was employed the ANOVA variance test (repeated measures). Differences were considered statistically significant at P < 0.05. Normal endothelium cells were mainly hexagonal (83.7%), pentagonal (7.45%) and heptagonal (8.8%), with a minimal number of cells of other shapes present. There were no significant statistical differences in the proportion of the morphology and the different regions of the cornea (P = 0.31).Discussion: Different techniques are available for the analysis of corneal endothelium, including mainly scanning electron microscopy, specular microscopy and optical microscopy. The analysis of the morphology of corneal endothelium with an optic microscope after staining with alizarin red has been described as an effective, rapid and cost-efficient method, since this dye blends the borated cells, allowing identification. In the present study, using optical microscopy and coloration with alizarin red it was possible to explore and to obtain images of the swine endothelium of all regions of the cornea.  The analysis of the cellular morphology or the percentage of hexagonal cells are among the main parameters used to evaluate the health of the corneal endothelium. In this study, the endothelium had the predominance of the hexagonal shape in all regions studied. In swine, there are no studies evaluating the shape of the endothelial cells in the five different regions of the cornea. This study has demonstrated that the parameters evaluated in swine did not differ significantly between the various places of the cornea

    Fatty acid synthase as a potential new therapeutic target for cervical cancer

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    Fatty acid synthase (FASN) is the rate-limiting enzyme for the de novo synthesis of fatty acids in the cytoplasm of tumour cells. Many tumour cells express high levels of FASN, and its expression is associated with a poorer prognosis. Cervical cancer is a major public health problem, representing the fourth most common cancer affecting women worldwide. To date, only a few in silico studies have correlated FASN expression with cervical cancer. This study aimed to investigate in vitro FASN expression in premalignant lesions and cervical cancer samples and the effects of a FASN inhibitor on cervical cancer cells. FASN expression was observed in all cervical cancer samples with increased expression at more advanced cervical cancer stages. The FASN inhibitor (orlistat) reduced the in vitro cell viability of cervical cancer cells (C-33A, ME-180, HeLa and SiHa) in a time-dependent manner and triggered apoptosis. FASN inhibitor also led to cell cycle arrest and autophagy. FASN may be a potential therapeutic target for cervical cancer, and medicinal chemists, pharmaceutical researchers and formulators should consider this fi nding in the development of new treatment approaches for this cancer type
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