170 research outputs found

    A New Method of Microcatheter Heat-Forming for Cerebral Aneurysmal Coiling Using Stereolithography Three-Dimensional Printed Hollow Vessel Models

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    [Background] To perform successful coil embolization of cerebral aneurysms, it is crucial to make an appropriately shaped microcatheter tip for an aneurysm and its parent artery. So far, we manually shaped a mandrel by referencing two-dimensional (2D) images of a rotation digital subtraction angiography (DSA) on a computer screen. However, this technique requires a lot of experience, and often involves trial and error. Recently, there have been increasing reports of manual mandrel shaping using a full-scale three-dimensional (3D) model of an aneurysm and its parent artery output by various types of 3D printer. We have further developed this method by producing a hollow model of an aneurysm and its parent artery with a stereolithography 3D printer and inserting a mandrel inside the model to fit and stabilize a microcatheter tip. [Methods] Based on digital imaging and communications in medicine (DICOM) data obtained by rotational DSA, 3D images of an aneurysm and its parent artery were created and converted into standard triangulated language (STL) data. A hollow model was produced by extruding the STL data outward in the normal direction, and then a hole was made at the tip of the aneurysm using these STL data. We output these STL data to a stereolithography 3D printer. After cleaning and sterilizing the model, the mandrel was inserted in the direction of the parent artery through the hole made in the tip of the aneurysm and pushed in, creating the ideal mandrel shape. Twelve cases (14 aneurysms) were included in this study. A microcatheter tip was shaped by this method for patients who were scheduled to undergo coil embolization for an unruptured aneurysm. [Results] In 13 of the 14 aneurysms, the microcatheter was easily guided into the aneurysms in one or two trials, the position of the microcatheter tip in the aneurysm was appropriate, and the stability during coil embolization was high. [Conclusion] Our method differs from the conventional one in that a hollow model made of resin is produced with a stereolithography 3D printer and that the mandrel is shaped by inserting it retrogradely into the hollow model. Using our new method, it will be possible to shape the tip of a microcatheter suitable for safe and stable coil embolization without relying on an operator’s experience

    The Effect of Electroacupuncture with Different Frequencies on Muscle Oxygenation in Humans

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    The aim of the present study was to investigate the effect of electroacupuncture (EA) with different frequencies on muscle oxygenation in humans. The subjects were 8 healthy male volunteers. Muscle oxygenation was measured using near-infrared spectroscopy (NIRS). Blood pressure (BP) and heart rate (HR) were monitored simultaneously. After baseline recording, EA was given for 15 min and recovery was measured for 20 minutes. The procedure of EA at 1 Hz, at 20 Hz, and at control followed in the same subjects. Tissue oxygenation index (TOI) decreased during EA at 20 Hz (P<0.05) and increased during the recovery period. Normalized tissue hemoglobin index (nTHI) also decreased during EA at 20 Hz and increased during the recovery period (P<0.05), whereas TOI and nTHI in the EA at 1 Hz did not change significantly throughout the experiment. The peak TOI and nTHI values at 20 Hz during the recovery period were higher than the values at 1 Hz and in the control (P<0.05). BP and HR remained constant. These data suggest that the supply of oxygen to muscle decreased during EA at 20 Hz and increased after EA at 20 Hz, without any changes in HR and BP

    The Nature of Ultra-Luminous Compact X-Ray Sources in Nearby Spiral Galaxies

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    Studies were made of ASCA spectra of seven ultra-luminous compact X-ray sources (ULXs) in nearby spiral galaxies; M33 X-8 (Takano et al. 1994), M81 X-6 (Fabbiano 1988b; Kohmura et al. 1994; Uno 1997), IC 342 Source 1 (Okada et al. 1998), Dwingeloo 1 X-1 (Reynolds et al. 1997), NGC 1313 Source B (Fabbiano & Trinchieri 1987; Petre et al. 1994), and two sources in NGC 4565 (Mizuno et al. 1999). With the 0.5--10 keV luminosities in the range 10^{39-40} ergs/s, they are thought to represent a class of enigmatic X-ray sources often found in spiral galaxies. For some of them, the ASCA data are newly processed, or the published spectra are reanalyzed. For others, the published results are quoted. The ASCA spectra of all these seven sources have been described successfully with so called multi-color disk blackbody (MCD) emission arising from optically-thick standard accretion disks around black holes. Except the case of M33 X-8, the spectra do not exhibit hard tails. For the source luminosities not to exceed the Eddington limits, the black holes are inferred to have rather high masses, up to ~100 solar masses. However, the observed innermost disk temperatures of these objects, Tin = 1.1--1.8 keV, are too high to be compatible with the required high black-hole masses, as long as the standard accretion disks around Schwarzschild black holes are assumed. Similarly high disk temperatures are also observed from two Galactic transients with superluminal motions, GRO 1655-40 and GRS 1915+105. The issue of unusually high disk temperature may be explained by the black hole rotation, which makes the disk get closer to the black hole, and hence hotter.Comment: submitted to ApJ, December 199

    Effect of probiotics on gut microbiome in patients with administration of surgical antibiotic prophylaxis: A randomized controlled study

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    Surgical antibiotic prophylaxis (SAP) is recommended for the prevention of surgical site infections. However, there is a concern about adverse effects of SAP, such as antibiotic-associated diarrhea (AAD). To prevent AAD, administration of probiotics has been investigated. Although recent advances in next-generation sequencing makes it possible to analyze the gut microbiome, the effect of probiotics on the gut microbiome in the patients with SAP remains unknown. To test a hypothesis that SAP influences the gut microbiome and probiotics prevent the influence, a randomized controlled study was conducted with patients who underwent spinal surgery at Nagasaki University Hospital. After obtaining informed consent, the patients were automatically classified into the non-probiotics group and the probiotics group. In the probiotics group, the patients took 1 g of Enterococcus faecium 129 BIO 3B-R, 3 times a day on postoperative days (PODs) 1–5. The feces of all patients were sampled before administration of SAP and on PODs 5 and 10. We compared alpha and beta diversity and differential abundance analysis of the gut microbiome before and after SAP. During the study period, a total of 33 patients were evaluated, comprising 17 patients in the non-probiotics group and 16 in the probiotics group. There was no significant difference between the groups regarding patient characteristics. In alpha and beta diversity, there were no significant differences among all combinations. In differential abundance analysis at operational taxonomic unit level, Streptococcus gallolyticus and Roseburia were significantly increased in the non-probiotics group and significantly decreased in the probiotics group

    The ASTRO-H X-ray Observatory

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    The joint JAXA/NASA ASTRO-H mission is the sixth in a series of highly successful X-ray missions initiated by the Institute of Space and Astronautical Science (ISAS). ASTRO-H will investigate the physics of the high-energy universe via a suite of four instruments, covering a very wide energy range, from 0.3 keV to 600 keV. These instruments include a high-resolution, high-throughput spectrometer sensitive over 0.3-2 keV with high spectral resolution of Delta E < 7 eV, enabled by a micro-calorimeter array located in the focal plane of thin-foil X-ray optics; hard X-ray imaging spectrometers covering 5-80 keV, located in the focal plane of multilayer-coated, focusing hard X-ray mirrors; a wide-field imaging spectrometer sensitive over 0.4-12 keV, with an X-ray CCD camera in the focal plane of a soft X-ray telescope; and a non-focusing Compton-camera type soft gamma-ray detector, sensitive in the 40-600 keV band. The simultaneous broad bandpass, coupled with high spectral resolution, will enable the pursuit of a wide variety of important science themes.Comment: 22 pages, 17 figures, Proceedings of the SPIE Astronomical Instrumentation "Space Telescopes and Instrumentation 2012: Ultraviolet to Gamma Ray

    The Quiescent Intracluster Medium in the Core of the Perseus Cluster

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    Clusters of galaxies are the most massive gravitationally-bound objects in the Universe and are still forming. They are thus important probes of cosmological parameters and a host of astrophysical processes. Knowledge of the dynamics of the pervasive hot gas, which dominates in mass over stars in a cluster, is a crucial missing ingredient. It can enable new insights into mechanical energy injection by the central supermassive black hole and the use of hydrostatic equilibrium for the determination of cluster masses. X-rays from the core of the Perseus cluster are emitted by the 50 million K diffuse hot plasma filling its gravitational potential well. The Active Galactic Nucleus of the central galaxy NGC1275 is pumping jetted energy into the surrounding intracluster medium, creating buoyant bubbles filled with relativistic plasma. These likely induce motions in the intracluster medium and heat the inner gas preventing runaway radiative cooling; a process known as Active Galactic Nucleus Feedback. Here we report on Hitomi X-ray observations of the Perseus cluster core, which reveal a remarkably quiescent atmosphere where the gas has a line-of-sight velocity dispersion of 164+/-10 km/s in a region 30-60 kpc from the central nucleus. A gradient in the line-of-sight velocity of 150+/-70 km/s is found across the 60 kpc image of the cluster core. Turbulent pressure support in the gas is 4% or less of the thermodynamic pressure, with large scale shear at most doubling that estimate. We infer that total cluster masses determined from hydrostatic equilibrium in the central regions need little correction for turbulent pressure.Comment: 31 pages, 11 Figs, published in Nature July
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