1,879 research outputs found
Acceleration Of Protons To Above 6 MeV Using H2O >Snow> Nanowire Targets
A scheme is presented for using H2O >snow> nanowire targets for the generation of fast protons. This novel method may relax the requirements for very high laser intensities, thus reducing the size and cost of laser based ion acceleration system.Physic
Influence of slope of rise and event order of aircraft noise events on high resolution actimetry parameters
Zusammenfassung: Starts und Landungen in der Nacht sind bei den meisten Verkehrsflughäfen durch eine Nachtflugsperre eingeschränkt. Die Empfindlichkeit der Bevölkerung, durch Fluglärm im Schlaf gestört zu werden, ist daher zu Randzeiten, also abends und morgens, besonders gross. In einer experimentellen Feldstudie bei Anwohnern in der Umgebung des Flughafens Zürich untersuchten wir die Wirkung von Fluglärmereignissen auf Körperreaktionen vor dem Aufwachen am Morgen. Dabei wurden in den Schlafzimmern der Versuchspersonen zuvor aufgezeichnete Fluglärm-Geräusche abgespielt. Mit einem nichtinvasiven Aufzeichnungsverfahren für schlafphysiologische Parameter (Hochauflösende Aktimetrie-, Herz- und Atemparameter) wurden Körperbewegungen ereigniskorreliert registriert. Die Resultate ergaben, dass vor allem die ersten paar Lärmereignisse am frühen Morgen die stärksten Reaktionen evozierten und diese mit zunehmender Anzahl erlebter Lärmereignisse abnehmen, was vermuten lässt, dass die zuvor erlebte Anzahl Überflüge eine systematische Wirkung hat, insbesondere wenn die Ereignisse innerhalb kurzer Zeitintervalle auftreten. Es zeigte sich auch, dass die Motilität von der Anstiegsgeschwindigkeit des Schallpegels abhängt, steilere Anstiegsflanken - wie sie typischerweise direkt unterhalb von Landeanflugschneisen auftreten - erzeugen stärkere Bewegungsreaktionen. Dies ist im Einklang mit einer neueren Untersuchung über den Zusammenhang zwischen nächtlichem Flug- und Eisenbahnlärm und Aufwachwahrscheinlichkei
Bad expression influences time to androgen escape in prostate cancer
<b>OBJECTIVE</b>: To assess the role of selected downstream Bcl-2 family members (Bad, Bax, Bcl-2 and Bcl-xL) in the development of androgen-independent prostate cancer (AIPC), as androgen-deprivation therapy is the treatment of choice in advanced prostate cancer, yet patients generally relapse and progress to an AI state within 18–24 months.
<b>PATIENTS, MATERIALS AND METHODS</b>: The patient cohort was established by retrospectively selecting patients with prostate cancer who had an initial response to androgen-deprivation therapy, but subsequently relapsed with AIPC. In all, 58 patients with prostate cancer were included with matched androgen-dependent (AD) and AI prostate tumours available for immunohistochemical analysis; two independent observers using a weighted-histoscore method scored the staining. Changes in Bad, Bax, Bcl-2 and Bcl-xL expression during transition to AIPC were evaluated and then correlated to known clinical variables.
<b>RESULTS</b>: High Bad expression in AD tumours was associated with an increased time to biochemical relapse (<i>P</i> = 0.007) and a trend towards improved overall survival (<i>P</i> = 0.053). There were also trends towards a decrease in Bad (<i>P</i> = 0.068) and Bax (<i>P</i> = 0.055) expression with progression to AIPC. There were no significant results for Bcl-2 or Bcl-xL.
<b>CONCLUSION</b>: There is evidence to suggest that Bad expression levels at diagnosis influence time to biochemical relapse and overall survival, and that levels of pro-apoptotic proteins Bad and Bax fall during AIPC development. Bad might therefore represent a possible positive prognostic marker and potential therapeutic target for AIPC in the future
Secretory Ameloblasts and Calcium Distribution During Normal and Experimentally Altered Mineralization
The distribution of calcium in relation to secretory ameloblasts of the rat incisor was studied. An experimental model system in which enamel mineralization was temporarily inhibited by injecting sodium fluoride and cobalt chloride was used. Potassium pyroantimonate (PPA) cytochemistry, electron energy loss spectroscopy (EELS), and energy dispersive X-ray spectrometry (EDS) were used to clarify the role of the ameloblast in controlling calcium distribution during normal and experimentally altered enamel mineralization.
Secretory ameloblasts chemically-preserved in glutaraldehyde either with or without PPA were analyzed for calcium; those preserved with PPA showed higher concentrations of calcium than did those preserved with glutaraldehyde only.
Freeze-dried control and experimental tissues showed an increasing gradient of calcium from stratum intermedium cells to the distal ends of the ameloblasts. Calcium levels were reduced near the distal ends of the cells following fluoride and cobalt injections, while magnesium levels were increased markedly in the same region.
This multi-method approach showed correlated calcium localization in specific regions of this cell in relation to changes in function. The study thus provides additional evidence for active involvement of the ameloblasts in enamel mineralization
Calcium Levels in Ruffle-Ended and Smooth-Ended Maturation Ameloblasts
Scanning electron microscopy was used to distinguish the topographical characteristics of two maturation ameloblast types in freeze-dried blocks of enamel organ tissue. This distinction was based primarily upon the configuration of the distal ends of the ameloblasts and the presence or absence of wide intercellular spaces.
Energy dispersive x-ray spectrometry was applied to compare calcium levels in various regions of tissue identified as constituting either ruffle-ended or smooth ended ameloblasts. Greater levels of calcium were found in the distal ends of the ruffle-ended cells than in their proximal ends. In addition, greater calcium levels were found in the distal ends of the ruffle-ended cells than the distal ends of the smooth-ended cells. The higher calcium levels in ruffle-ended cells correlates with the view that these cells are actively involved in control of movement of calcium to the enamel front
5.5-7.5 MeV Proton generation by a moderate intensity ultra-short laser interaction with H2O nano-wire targets
We report on the first generation of 5.5-7.5 MeV protons by a moderate
intensity short-pulse laser (4.5 \times 1017 W/cm^2, 50 fsec) interacting with
H2O nano-wires (snow) deposited on a Sapphire substrate. In this setup, the
laser intensity is locally enhanced by the tip of the snow nano-wire, leading
to high spatial gradients. Accordingly, the plasma near the tip is subject to
enhanced ponderomotive potential, and confined charge separation is obtained.
Electrostatic fields of extremely high intensities are produced over the short
scale length, and protons are accelerated to MeV-level energies.Comment: submitted to PRL, under press embargo. 6 figure
Effect of Fluoride and Cobalt on Forming Enamel: Scanning Electron Microscope and X-Ray Microanalysis Study
The forming surfaces of enamel of rat incisors were examined by scanning electron microscope one hour after injection of either 5 mg/100 g body weight of sodium fluoride or 12 mg/100 g body weight of cobalt chloride. The cell debris from the surfaces of the separated incisors was either gently wiped off with soft facial tissues or chemically removed by treating with NaOH, NaOCl or trypsin. Best results to remove cell debris were obtained from 0.25% trypsin treatment.
SEM studies revealed that the surface of the normal secretory enamel was characteristic in appearance with well-developed smooth prism outlines. In fluoride specimens the prism outlines were feathery in appearance, laced with protruding spine-shaped clusters of mineral crystals. In the case of cobalt treatment, prism outlines were less uniform and in some areas they were incomplete.
The calcium concentration of surface enamel was significantly lower in the cobalt-treated specimens than those from control and fluoride-treated animals. The Ca:Mg ratio was also lower in cobalt-treated specimens as compared to control and fluoride-treated ones
Componential coding in the condition monitoring of electrical machines Part 2: application to a conventional machine and a novel machine
This paper (Part 2) presents the practical application of componential coding, the principles of which were described in the accompanying Part 1 paper. Four major issues are addressed, including optimization of the neural network, assessment of the anomaly detection results, development of diagnostic approaches (based on the reconstruction error) and also benchmarking of componential coding with other techniques (including waveform measures, Fourier-based signal reconstruction and principal component analysis). This is achieved by applying componential coding to the data monitored from both a conventional induction motor and from a novel transverse flux motor. The results reveal that machine condition monitoring using componential coding is not only capable of detecting and then diagnosing anomalies but it also outperforms other conventional techniques in that it is able to separate very small and localized anomalies
Surrogate-based optimization of tidal turbine arrays: a case study for the Faro-OlhĂŁo inlet
This paper presents a study for estimating the size of a tidal turbine array for the Faro-Olhão Inlet (Potugal) using a surrogate optimization approach. The method compromises problem formulation, hydro-morphodynamic modelling, surrogate construction and validation, and constraint optimization. A total of 26 surrogates were built using linear RBFs as a function of two design variables: number of rows in the array and Tidal Energy Converters (TECs) per row. Surrogates describe array performance and environmental effects associated with hydrodynamic and morphological aspects of the multi inlet lagoon. After validation, surrogate models were used to formulate a constraint optimization model. Results evidence that the largest array size that satisfies performance and environmental constraints is made of 3 rows and 10 TECs per row.Eduardo González-Gorbeña has received funding for the OpTiCA project (http://msca-optica.eu/) from the Marie Skłodowska-Curie Actions of the European Union's H2020-MSCA-IF-EF-RI-2016 / GA#: 748747. The paper is a contribution to the SCORE pro-ject, funded by the Portuguese Foundation for Science and Technology (FCT–PTDC/AAG-TEC/1710/2014). André Pacheco was supported by the Portuguese Foun-dation for Science and Technology under the Portuguese Researchers’ Programme 2014 entitled “Exploring new concepts for extracting energy from tides” (IF/00286/2014/CP1234).info:eu-repo/semantics/publishedVersio
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