35 research outputs found

    FDG-PET/CT is useful in the diagnosis of early phase Takayasu's arteritis : A case report

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    A 60-year-old female patient was admitted to our hospital in April, 2010 because of low-grade fever and malaise for several months. Physical examination on admission revealed no abnormalities except for a body temperature of 37.2℃. Blood examinations showed moderate anemia and a high erythrocyte sedimentation rate. There were no other specific abnormal findings. A systemic CT scan study disclosed diffuse thickening of the artery wall through the ascending, descending and abdominal aorta to the bilateral iliac arteries. In order to evaluate the quality of the vessel lesions, a FDG-PET/CT study was performed and revealed abnormal accumulation of 18F-FDG in the thickened wall, suggesting an inflammatory process in the lesion. Taking all these findings into consideration, we made the diagnosis of Takayasu's arteritis, and treated the patient with prednisolone. The treatment was effective and her symptoms improved. A later CT scan revealed that the artery wall became somewhat thinner. Takayasu's arteritis is a disease whose diagnosis is difficult to make because there are neither specific signs nor diagnostic laboratory findings in its early stage. We found that FDG-PET/CT was helpful in the diagnosis and evaluation of lesions in a patient with Takayasu's arteritis

    Essential roles of the interaction between cancer cell-derived chemokine, CCL4, and intra-bone CCR5-expressing fibroblasts in breast cancer bone metastasis

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    From a murine breast cancer cell line, 4T1, we established a subclone, 4T1.3, which consistently metastasizes to bone upon its injection into the mammary fat pad. 4T1.3 clone exhibited similar proliferation rate and migration capacity as the parental clone. However, the intra-bone injection of 4T1.3 clone caused larger tumors than that of the parental cells, accompanied with increases in fibroblast, but not osteoclast or osteoblast numbers. 4T1.3 clone displayed an enhanced expression of a chemokine, CCL4, but not its specific receptor, CCR5. CCL4 shRNA-transfection of 4T1.3 clone had few effects on its in vitro properties, but reduced the tumorigenicity arising from the intra-bone injection. Moreover, intra-bone injection of 4T1.3 clone caused smaller tumors in mice deficient in CCR5 or those receiving CCR5 antagonist than in wild-type mice. The reduced tumor formation was associated with attenuated accumulation of CCR5-positive fibroblasts expressing connective tissue growth factor (CTGF)/CCN2. Tumor cell-derived CCL4 could induce fibroblasts to express CTGF/CCN2, which could support 4T1.3 clone proliferation under hypoxic culture conditions. Thus, the CCL4-CCR5 axis can contribute to breast cancer metastasis to bone by mediating the interaction between cancer cells and fibroblasts in bone cavity. © 2016 Elsevier Ireland Ltd.Embargo Period 12 month

    Observation of gravitational waves from the coalescence of a 2.5−4.5 M⊙ compact object and a neutron star

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    Search for gravitational-lensing signatures in the full third observing run of the LIGO-Virgo network

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    Gravitational lensing by massive objects along the line of sight to the source causes distortions of gravitational wave-signals; such distortions may reveal information about fundamental physics, cosmology and astrophysics. In this work, we have extended the search for lensing signatures to all binary black hole events from the third observing run of the LIGO--Virgo network. We search for repeated signals from strong lensing by 1) performing targeted searches for subthreshold signals, 2) calculating the degree of overlap amongst the intrinsic parameters and sky location of pairs of signals, 3) comparing the similarities of the spectrograms amongst pairs of signals, and 4) performing dual-signal Bayesian analysis that takes into account selection effects and astrophysical knowledge. We also search for distortions to the gravitational waveform caused by 1) frequency-independent phase shifts in strongly lensed images, and 2) frequency-dependent modulation of the amplitude and phase due to point masses. None of these searches yields significant evidence for lensing. Finally, we use the non-detection of gravitational-wave lensing to constrain the lensing rate based on the latest merger-rate estimates and the fraction of dark matter composed of compact objects

    Search for eccentric black hole coalescences during the third observing run of LIGO and Virgo

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    Despite the growing number of confident binary black hole coalescences observed through gravitational waves so far, the astrophysical origin of these binaries remains uncertain. Orbital eccentricity is one of the clearest tracers of binary formation channels. Identifying binary eccentricity, however, remains challenging due to the limited availability of gravitational waveforms that include effects of eccentricity. Here, we present observational results for a waveform-independent search sensitive to eccentric black hole coalescences, covering the third observing run (O3) of the LIGO and Virgo detectors. We identified no new high-significance candidates beyond those that were already identified with searches focusing on quasi-circular binaries. We determine the sensitivity of our search to high-mass (total mass M>70 M⊙) binaries covering eccentricities up to 0.3 at 15 Hz orbital frequency, and use this to compare model predictions to search results. Assuming all detections are indeed quasi-circular, for our fiducial population model, we place an upper limit for the merger rate density of high-mass binaries with eccentricities 0<e≤0.3 at 0.33 Gpc−3 yr−1 at 90\% confidence level

    Ultralight vector dark matter search using data from the KAGRA O3GK run

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    Among the various candidates for dark matter (DM), ultralight vector DM can be probed by laser interferometric gravitational wave detectors through the measurement of oscillating length changes in the arm cavities. In this context, KAGRA has a unique feature due to differing compositions of its mirrors, enhancing the signal of vector DM in the length change in the auxiliary channels. Here we present the result of a search for U(1)B−L gauge boson DM using the KAGRA data from auxiliary length channels during the first joint observation run together with GEO600. By applying our search pipeline, which takes into account the stochastic nature of ultralight DM, upper bounds on the coupling strength between the U(1)B−L gauge boson and ordinary matter are obtained for a range of DM masses. While our constraints are less stringent than those derived from previous experiments, this study demonstrates the applicability of our method to the lower-mass vector DM search, which is made difficult in this measurement by the short observation time compared to the auto-correlation time scale of DM

    Surface Potential Visualization in Organic Antiambipolar Transistors Using Operando Kelvin Probe Force Microscopy for Understanding the Comprehensive Carrier Transport Mechanism

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    Abstract An antiambipolar transistor (AAT) exhibits a negative differential transconductance (NDT) due to a partially overlapped p–n junction formed in the transistor channel. However, the NDT origin remains unclear. In this study, the operando Kelvin probe force microscopy is employed to unveil this issue. When the AAT is turned on, steep potential drops induced by pinch‐off states are visible in the p‐ and n‐type channels. Due to the similarity to the surface potential profiles in the constituent transistors, it is revealed that the pinch‐off points are formed at both edges of the p–n‐stacked layers. This result indicates that the overlapped layers behave like a pseudo‐drain electrode for both transistor channels. Therefore, the AAT drain current can be explained as the overlapped currents in the saturation regions of the p‐ and n‐type transistors. Moreover, the drain current is suppressed when either the p‐ or n‐type channel is completely depleted. The depletion layer formation is responsible for the NDT property. This technique provides a comprehensive understanding of the carrier transport mechanism of AATs, leading to the further evolution of organic electronic circuits

    A Relationship between Movement Time and Traveled Distances in Forward/Backward direction Cooperative Task

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    Abstract. The research main objective was to generate a smooth cooperative rigid object transfer by a human hand and a robot manipulator mimicking the same task performs by two humans. In achieving such objective, the relationship between movement time and traveled distances of the cooperative task performed by two humans were investigated. A motion capture system was utilized to record the movement of two subjects namely, Leader and Follower during the cooperative transfer of an object using their right hands in a seated position. The cooperative task was performed in forward/backward directions relative to the Leader. The Leader informed the Follower on the onset and the terminating position prior to the execution of the cooperative task. Both subjects moved the object towards the target together. The results show a linear relationship between movement time and traveled distances. Both subjects were found to have similar relationship for the cooperative task in the same direction. In forward/backward cooperative task, the direction is not significant in influencing the relationship between movement time and traveled distances. The relationship will be tested with robotic motion in the next phase of the research
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