4,435 research outputs found

    Fe I line shifts in the optical spectrum of the Sun

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    New improvements in the measurement of both the optical solar spectrum and laboratory wavelengths for lines of neutral iron are combined to extract central wavelength shifts for 1446 lines observed in the Sun. This provides the largest available database of accurate solar wavelengths useful as a reference for comparison with other solar-type stars. It is shown how the velocity shifts correlate with line strength, approaching a constant value, close to zero, for lines with equivalent widths larger than 200 mA.Comment: Latex file (5 pages), uses l-aa.sty and epsfig.sty (included); 3 Postscript figures, 1 ASCII table, accepted for publication in Astronomy and Astrophysics Supplement Serie

    A catalogue of accurate wavelengths in the optical spectrum of the Sun

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    We present accurate measurements of the central wavelengths of 4947 atomic absorption lines in the solar optical spectrum. The wavelengths, precise to a level ~ 50-150 m/s, are given for both flux and disc-centre spectra, as measured in relatively recent FTS solar atlases. This catalogue modernizes existing sources based on photographic measurements and provides a benchmark to test and perform wavelength calibrations of astronomical spectra. It will also permit observers to improve the absolute wavelength calibration of solar optical spectra when lamps are not available at the telescope.Comment: 3 pages, 1 ASCII table (4947 records, download the source to view); uses aa.cls (included); accepted for publication in A&A

    La regulacion global de los medicamentos herbarios

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    El Balsamo de Fierabras

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    Role of beta-adrenergic modulation in myocardial ischemia/reperfusion injury. Mechanisms underlyning cardioprotection

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    The β-adrenergic system plays an important role in the regulation of heart function. The early intravenous administration of ß1-adrenergic receptor (ADRB1)-antagonist, metoprolol, in patients with ST-segment elevation acute myocardial infarction (AMI) reduces the extent of infarct size. The prevailing view has been that metoprolol acts mainly on cardiomyocytes function, reducing cardiac output. This work presents evidence that metoprolol reduces ischemia/reperfusion injury by targeting the hematopoietic compartment, specifically by inhibiting neutrophil function through an ADRB1 signallingdependent manner. Metoprolol acts during early phases of neutrophil recruitment, impairing structural and functional rearrangements necessary for effective interactions with circulating platelets to occur. Metoprolol, “stuns” neutrophils that cannot engage the structural conformation necessary to infiltrate tissues, triggering erratic intravascular dynamics and overall blunted inflammation. The in vitro functional assays confirm direct effect on neutrophils through an ADRB1-dependent mechanism. The depletion of circulating neutrophils, the lack of the Adrb1 in hematopoietic cells and the blockade of P-selectin glycoprotein ligand-1, the receptor involved in neutrophil-platelet interactions, result in a complete abrogation of metoprolol´s infarct-limiting effect. Moreover, the association between neutrophil count and microvascular obstruction is abolished in early metoprolol-treated AMI patients. Metoprolol has no direct effect on platelet function, but inhibits neutrophil-platelet interactions in AMI patients by targeting neutrophils directly. Identification of the relevant role of ADRB1 in hematopoietic cells during acute injury and the protective role upon its modulation offers potential for developing new therapeutic strategies.This work was supported by a competitive grant from the Spanish Ministry of Economy and Competitiveness (MINECO) through the Carlos III Institute of Health-Fondo de Investigación Sanitaria FIS-ISCIII (PI13/01979) and FISISCIII (PI10/02268), Fundacion Mutua Madrileña (AP8695-2011), from the competitive ‘‘CNIC translational 01/2009’’ and European Regional Development Fund (ERDF/FEDER) funds (PI10/02268 & PI13/01979). The CNIC is supported by the Spanish Ministry of Economy and Competitiveness (MINECO) and the Pro-CNIC Foundation, and is a Severo Ochoa Center of Excellence (MINECO award SEV-2015-0505)

    Stability of Feverfew and its Active Principle Parthenolide: An Elusive Antimigraine Herbal Medicine

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    Background Feverfew is a traditional herbal remedy for the relief of arthritis, migraine, toothache, and menstrual difficulties. It is widely accepted that parthenolide, a sesquiterpene lactone, is its main active principle. However, the decrease of parthenolide in commercial preparations is a well-known process with no technical solution so far. Aims To review the evidence for the mechanism of the degradation of parthenolide and similar sesquiterpene lactones. Methods Systematic review. Results and Conclusion In conclusion, and without discarding any degradation of parthenolide into non-identifiable fragments, the fate of this compound in dry, powdered feverfew is to undergo a covalent binding to plant proteins resulting in a biologically inactive adduct - in accordance with the direct and indirect data found in the literature. This process seems to be virtually unstoppable, and temperature and light do not seem to be playing a significant role under normal storage conditions according to some authors. In the presence of a high level of humidity, parthenolide may undergo an acid-induced cyclisation giving rise to a guaianolide-type sesquiterpene lactone, a class of compound that is commonly found in Feverfew. Microbial degradations are not likely to play an important role if the formulation complies with Pharmacopoeial microbiological quality requirements. The experimental and clinical data in the literature do not report on any increase in the toxicity of stored feverfew.&nbsp
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