80 research outputs found

    The potential of the antiplatelet agent ticagrelor as a new antibacterial agent

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    The number of deaths caused by drug-resistant bacteria is expected to increase in the future, and there is a need to develop new antimicrobial agents. Recently, the antiplatelet drug ticagrelor has been reported to have promising antibacterial properties. The purpose of this review is to analyze articles and case reports that describe the antimicrobial action of ticagrelor. Ticagrelor was found to have antibacterial reactions against Gram-positive bacteria, including drug-resistant and spore-forming bacteria, while no effect was observed against Gram-negative bacteria. In this paper we discuss a new potential antimicrobial agent, ticagrelor.The number of deaths caused by drug-resistant bacteria is expected to increase in the future, and there is a need to develop new antimicrobial agents. Recently, the antiplatelet drug ticagrelor has been reported to have promising antibacterial properties. The purpose of this review is to analyze articles and case reports that describe the antimicrobial action of ticagrelor. Ticagrelor was found to have antibacterial reactions against Gram-positive bacteria, including drug-resistant and spore-forming bacteria, while no effect was observed against Gram-negative bacteria. In this paper we discuss a new potential antimicrobial agent, ticagrelor

    The potential of the antiplatelet agent ticagrelor as a new antibacterial agent

    Get PDF
    The number of deaths caused by drug-resistant bacteria is expected to increase in the future, and there is a need to develop new antimicrobial agents. Recently, the antiplatelet drug ticagrelor has been reported to have promising antibacterial properties. The purpose of this review is to analyze articles and case reports that describe the antimicrobial action of ticagrelor. Ticagrelor was found to have antibacterial reactions against Gram-positive bacteria, including drug-resistant and spore-forming bacteria, while no effect was observed against Gram-negative bacteria. In this paper we discuss a new potential antimicrobial agent, ticagrelor.The number of deaths caused by drug-resistant bacteria is expected to increase in the future, and there is a need to develop new antimicrobial agents. Recently, the antiplatelet drug ticagrelor has been reported to have promising antibacterial properties. The purpose of this review is to analyze articles and case reports that describe the antimicrobial action of ticagrelor. Ticagrelor was found to have antibacterial reactions against Gram-positive bacteria, including drug-resistant and spore-forming bacteria, while no effect was observed against Gram-negative bacteria. In this paper we discuss a new potential antimicrobial agent, ticagrelor

    Measuring the Broad-band X-Ray Spectrum from 400 eV to 40 keV in the Southwest Part of the Supernova Remnant RX J1713.7-3946

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    We report on results from Suzaku broadband X-ray observations of the southwest part of the Galactic supernova remnant (SNR) RX J1713.7-3946 with an energy coverage of 0.4-40 keV. The X-ray spectrum, presumably of synchrotron origin, is known to be completely lineless, making this SNR ideally suited for a detailed study of the X-ray spectral shape formed through efficient particle acceleration at high speed shocks. With a sensitive hard X-ray measurement from the HXD PIN on board Suzaku, we determine the hard X-ray spectrum in the 12--40 keV range to be described by a power law with photon index Gamma = 3.2+/- 0.2, significantly steeper than the soft X-ray index of Gamma = 2.4+/- 0.05 measured previously with ASCA and other missions. We find that a simple power law fails to describe the full spectral range of 0.4-40 keV and instead a power-law with an exponential cutoff with hard index Gamma = 1.50+/- 0.09 and high-energy cutoff epsilon_c = 1.2+/- 0.3 keV formally provides an excellent fit over the full bandpass. If we use the so-called SRCUT model, as an alternative model, it gives the best-fit rolloff energy of epsilon_{roll} = 0.95+/- 0.04 keV. Together with the TeV gamma-ray spectrum ranging from 0.3 to 100 TeV obtained recently by HESS observations, our Suzaku observations of RX J1713.7-3946 provide stringent constraints on the highest energy particles accelerated in a supernova shock.Comment: 11 pages, 11 figures, accepted for publication in Publications of the Astronomical Society of Japan (PASJ

    Iron and Nickel Line Diagnostics for the Galactic Center Diffuse Emission

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    We have observed the diffuse X-ray emission from the Galactic center (GC) using the X-ray Imaging Spectrometer (XIS) on Suzaku. The high-energy resolution and the low-background orbit provide excellent spectra of the GC diffuse X-rays (GCDX). The XIS found many emission lines in the GCDX near the energy of K-shell transitions of iron and nickel. The most pronounced features are FeI K alpha at 6.4 keV and K-shell absorption edge at 7.1 keV, which are from neutral and/or low ionization states of iron, and the K-shell lines at 6.7 keV and 6.9 keV from He-like (FeXXV K alpha) and hydrogenic (FeXXVI Ly alpha) ions of iron. In addition, K alpha lines from neutral or low ionization nickel (NiI K alpha) and He-like nickel (NiXXVII K alpha), and FeI K beta, FeXXV K beta, FeXXVI Ly beta, FeXXV K gamma and FeXXVI Ly gamma are detected for the first time. The line center energies and widths of FeXXV K alpha and FeXXVI Ly alpha favor a collisional excitation (CE) plasma for the origin of the GCDX. The electron temperature determined from the line flux ratio of FeXXV K alpha / FeXXV K beta is similar to the ionization temperature determined from that of FeXXV K alpha /FeXXVI Ly alpha. Thus it would appear that the GCDX plasma is close to ionization equilibrium. The 6.7 keV flux and temperature distribution to the galactic longitude is smooth and monotonic,in contrast to the integrated point source flux distribution. These facts support the hypothesis that the GCDX is truly diffuse emission rather than the integration of the outputs of a large number of unresolved point sources. In addition, our results demonstrate that the chemical composition of Fe in the interstellar gas near the GC is constrained to be about 3.5 times solar.Comment: 11 pages, 19 figures. Accepted for publication in PASJ Suzaku Special Issue (vol. 59 sp. 1

    Analysis of mineral apposition rates during alveolar bone regeneration over three weeks following transfer of BMP-2/7 gene via in vivo electroporation

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    Alveolar bone is not spontaneously regenerated following trauma or periodontitis. We previously proposed an animal model for new alveolar bone regeneration therapy based on the non-viral BMP-2/7 gene expression vector and in vivo electroporation, which induced the formation of new alveolar bone over the course of a week. Here, we analysed alveolar bone during a period of three weeks following gene transfer to periodontal tissue. Non-viral plasmid vector pCAGGS-BMP-2/7 or pCAGGS control was injected into palatal periodontal tissue of the first molar of the rat maxilla and immediately electroporated with 32 pulses of 50 V for 50 msec. Over the following three weeks, rats were double bone-stained by calcein and tetracycline every three days and mineral apposition rates (MAR) were measured. Double bone-staining revealed that MAR of alveolar bone was as similar level three days before BMP-2/7 gene transfer as three days after gene transfer. However, from 3 to 6 days, 6 to 9 days, 9 to 12 days, 12 to 15 days, 15 to 18 days, and 18 to 20 days after, MARs were significantly higher than prior to gene transfer. Our proposed gene therapy for alveolar bone regeneration combining non-viral BMP-2/7 gene expression vector and in vivo electroporation could increase alveolar bone regeneration potential in the targeted area for up to three weeks

    Soft Gamma-ray Detector for the ASTRO-H Mission

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    ASTRO-H is the next generation JAXA X-ray satellite, intended to carry instruments with broad energy coverage and exquisite energy resolution. The Soft Gamma-ray Detector (SGD) is one of ASTRO-H instruments and will feature wide energy band (40-600 keV) at a background level 10 times better than the current instruments on orbit. SGD is complimentary to ASTRO-H's Hard X-ray Imager covering the energy range of 5-80 keV. The SGD achieves low background by combining a Compton camera scheme with a narrow field-of-view active shield where Compton kinematics is utilized to reject backgrounds. The Compton camera in the SGD is realized as a hybrid semiconductor detector system which consists of silicon and CdTe (cadmium telluride) sensors. Good energy resolution is afforded by semiconductor sensors, and it results in good background rejection capability due to better constraints on Compton kinematics. Utilization of Compton kinematics also makes the SGD sensitive to the gamma-ray polarization, opening up a new window to study properties of gamma-ray emission processes. The ASTRO-H mission is approved by ISAS/JAXA to proceed to a detailed design phase with an expected launch in 2014. In this paper, we present science drivers and concept of the SGD instrument followed by detailed description of the instrument and expected performance.Comment: 17 pages, 15 figures, Proceedings of the SPIE Astronomical Instrumentation "Space Telescopes and Instrumentation 2010: Ultraviolet to Gamma Ray

    PoGOLite - A High Sensitivity Balloon-Borne Soft Gamma-ray Polarimeter

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    We describe a new balloon-borne instrument (PoGOLite) capable of detecting 10% polarisation from 200mCrab point-like sources between 25 and 80keV in one 6 hour flight. Polarisation measurements in the soft gamma-ray band are expected to provide a powerful probe into high-energy emission mechanisms as well as the distribution of magnetic fields, radiation fields and interstellar matter. At present, only exploratory polarisation measurements have been carried out in the soft gamma-ray band. Reduction of the large background produced by cosmic-ray particles has been the biggest challenge. PoGOLite uses Compton scattering and photo-absorption in an array of 217 well-type phoswich detector cells made of plastic and BGO scintillators surrounded by a BGO anticoincidence shield and a thick polyethylene neutron shield. The narrow FOV (1.25msr) obtained with well-type phoswich detector technology and the use of thick background shields enhance the detected S/N ratio. Event selections based on recorded phototube waveforms and Compton kinematics reduce the background to that expected for a 40-100mCrab source between 25 and 50keV. A 6 hour observation on the Crab will differentiate between the Polar Cap/Slot Gap, Outer Gap, and Caustic models with greater than 5 sigma; and also cleanly identify the Compton reflection component in the Cygnus X-1 hard state. The first flight is planned for 2010 and long-duration flights from Sweden to Northern Canada are foreseen thereafter.Comment: 11 pages, 11 figures, 2 table
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