278 research outputs found

    Pseudoaneurysm of Lumbar Artery following a Vertebral Biopsy: A Case Report

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    A 74-year-old man developed a severe low back pain and a fever. In the initial examinations, a collapse of the L5 anterosuperior vertebral body and narrowing of the L4/5 disc space were identified on radiographs, and the laboratory data showed inflammatory results. A computed tomography (CT) and a magnetic resonance imaging showed collapse of L5. A needle biopsy was performed to make a diagnosis; however, an abdominal pain and a hypotension appeared after the biopsy. An abdominal CT showed a hematoma in the retroperitoneal space, and an angiography revealed a left fourth lumbar artery pseudoaneurysm. The pseudoaneurysm was treated with transcatheter placement of microcoils. Although haemorrhagic complications following needle biopsy are very rare, patients with large amounts of vertebral destruction may have unusual anatomical positions of the lumber artery. Therefore, surgeons should be aware of the possibility of lumbar artery injury during a needle biopsy and take care of prebiopsy plans

    Mechanism of strong quenching of photosystem II chlorophyll fluorescence under drought stress in a lichen, Physciella melanchla, studied by subpicosecond fluorescence spectroscopy

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    AbstractThe mechanism of the severe quenching of chlorophyll (Chl) fluorescence under drought stress was studied in a lichen Physciella melanchla, which contains a photobiont green alga, Trebouxia sp., using a streak camera and a reflection-mode fluorescence up-conversion system. We detected a large 0.31 ps rise of fluorescence at 715 and 740 nm in the dry lichen suggesting the rapid energy influx to the 715–740 nm bands from the shorter-wavelength Chls with a small contribution from the internal conversion from Soret bands. The fluorescence, then, decayed with time constants of 23 and 112 ps, suggesting the rapid dissipation into heat through the quencher. The result confirms the accelerated 40 ps decay of fluorescence reported in another lichen (Veerman et al., 2007 [36]) and gives a direct evidence for the rapid energy transfer from bulk Chls to the longer-wavelength quencher. We simulated the entire PS II fluorescence kinetics by a global analysis and estimated the 20.2 ns−1 or 55.0 ns−1 energy transfer rate to the quencher that is connected either to the LHC II or to the PS II core antenna. The strong quenching with the 3–12 times higher rate compared to the reported NPQ rate, suggests the operation of a new type of quenching, such as the extreme case of Chl-aggregation in LHCII or a new type of quenching in PS II core antenna in dry lichens

    Plasmon-enhanced molecular fluorescence from an organic film in a tunnel junction

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    Scanning tunneling microscope (STM)-excited molecular fluorescence from H2TBP porphyrin (H2TBPP) thin films on Au (111), Ag, highly oriented pyrolytic graphite (HOPG), and indium tin oxide (ITO) surfaces has been investigated in air. Molecular fluorescence was observed from the H2TBPP films on Au and Ag, but it was extremely weak or undetectable from films on HOPG and ITO. The maximum intensity of molecular fluorescence from H2TBPP/Ag is at least 100 times stronger than that from H2TBPP/HOPG. Strong enhancement of molecular excitation by substrate surface plasmons is suggested for the STM-excited molecular fluorescence from H2TBPP only on the noble metal substrates

    Plasmon-enhanced molecular fluorescence from an organic film in a tunnel junction

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    Scanning tunneling microscope (STM)-excited molecular fluorescence from H2TBP porphyrin (H2TBPP) thin films on Au (111), Ag, highly oriented pyrolytic graphite (HOPG), and indium tin oxide (ITO) surfaces has been investigated in air. Molecular fluorescence was observed from the H2TBPP films on Au and Ag, but it was extremely weak or undetectable from films on HOPG and ITO. The maximum intensity of molecular fluorescence from H2TBPP/Ag is at least 100 times stronger than that from H2TBPP/HOPG. Strong enhancement of molecular excitation by substrate surface plasmons is suggested for the STM-excited molecular fluorescence from H2TBPP only on the noble metal substrates

    Alfven Wave Amplification and Self-Containment of Cosmic-Rays Escaping from a Supernova Remnant

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    We study the escape of cosmic-ray (CR) protons accelerated at a supernova remnant (SNR) by numerically solving a diffusion-convection equation from the vicinity of the shock front to the region far away from the front. We consider the amplifications of Alfven waves generated by the escaping CR particles and their effects on CR escape into interstellar medium (ISM). We find that the amplification of the waves significantly delays the escape of the particles even far away from the shock front (on a scale of the SNR). This means that the energy spectrum of CR particles measured through gamma-ray observations at molecular clouds around SNRs is seriously affected by the particle scattering by the waves.Comment: Accepted for publication in MNRA

    Experience with the Vibrant Soundbridge RW-Coupler for round window Vibroplasty with tympanosclerosis

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    Usage of the Vibrant Soundbridge (VSB) with round window (RW)-Coupler placement at the RW has been shown to successfully treat mixed hearing loss. Coupling between the VSB's floating mass transducer (FMT) and the RW membrane is difficult in the case of sclerosis in the RW and drilling down the bony lip until the RW membrane can be seen completely can possibly induce a perilymphatic fistula. A 68-year-old woman who had bilateral mixed hearing loss with sclerosis in the RW due to tympanosclerosis underwent a RW-Vibroplasty with a RW-Coupler. Speech discrimination scores in quiet and noise and functional gain with the VSB with RW-Coupler were better than those using a conventional hearing aid. The results of the present case have shown the feasibility of implanting a VSB with RW-Coupler in patients with mixed hearing loss due to tympanosclerosis.ArticleACTA OTO-LARYNGOLOGICA. 132(6):676-682 (2012)journal articl
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