1,667 research outputs found
Generalizing Planck's distribution by using the Carati-Galgani model of molecular collisions
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
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
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. BĂĽcker et al. (1999)
oder Helm-Clark et al. (2004) haben
bereits gezeigt, dass sich Messungen
der natĂĽrlichen Gammastrahlung (GR),
die ĂĽblicherweise 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 zurĂĽckzufĂĽhren.
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 durchgefĂĽhrt. 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
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
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
Geo-Biological Investigations on Azooxanthellate Cold-Water Coral Reefs on the Carbonate Mounds Along the Celtic Continental Slope
Northeast Atlantic 2004 Cruise No. 61, Leg 1 April 19 to May 4, 2004, Lisbon – Cor
Fatty acid synthase as a potential new therapeutic target for cervical cancer
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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