85 research outputs found

    High abundance ratio of 13^{13}CO to C18^{18}O toward photon-dominated regions in the Orion-A giant molecular cloud

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    Aims. We derive physical properties such as the optical depths and the column densities of 13^{13}CO and C18^{18}O to investigate the relationship between the far ultraviolet (FUV) radiation and the abundance ratios between 13^{13}CO and C18^{18}O. Method. We have carried out wide-field (0.4 deg2^2) observations with an angular resolution of 25.8 arcsec (\sim 0.05 pc) in 13^{13}CO (JJ=1--0) and C18^{18}O (JJ=1--0) toward the Orion-A giant molecular cloud using the Nobeyama 45 m telescope in the on-the-fly mode. Results. Overall distributions and velocity structures of the 13^{13}CO and C18^{18}O emissions are similar to those of the 12^{12}CO (JJ=1--0) emission. The optical depths of the 13^{13}CO and C18O emission lines are estimated to be 0.05 << τ13CO\tau_{\rm ^{13}CO} << 1.54 and 0.01 << τC18O\tau_{\rm C^{18}O} << 0.18, respectively. The column densities of the 13^{13}CO and C18^{18}O emission lines are estimated to be 0.2 ×\times 1016^{16} << N13CON_{\rm ^{13}CO} << 3.7 ×\times 1017^{17} cm2^{-2} and 0.4 ×\times 1015^{15} << NC18ON_{\rm C^{18}O} << 3.5 ×\times 1016^{16} cm2^{-2}, respectively. The abundance ratios between 13^{13}CO and C18^{18}O, X13COX_{\rm ^{13}CO}/XC18OX_{\rm C^{18}O}, are found to be 5.7 - 33.0. The mean value of X13COX_{\rm ^{13}CO}/XC18OX_{\rm C^{18}O} in the nearly edge-on photon-dominated regions is found to be 16.47 ±\pm 0.10, which is a third larger than that the solar system value of 5.5. The mean value of X13COX_{\rm ^{13}CO}/XC18OX_{\rm C^{18}O} in the other regions is found to be 12.29 ±\pm 0.02. The difference of the abundance ratio is most likely due to the selective FUV photodissociation of C18^{18}O.Comment: 11 pages, 9 figures, Accepted to A&

    Relationships between Cytokine Profiles and Signaling Pathways (IκB Kinase and p38 MAPK) in Parainfluenza Virus-Infected Lung Fibroblasts

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    Respiratory viruses such as parainfluenza virus (PIV) in individuals with certain genetic predispositions in early life are associated with the induction of wheezing, which can progress to the development of asthma. It has been suggested that aberrant production of various cytokines due to viral infection are associated with virus-induced asthma. However, the mechanisms of how respiratory viruses induce and exacerbate asthma have yet to be clarified. To examine cytokine responses to PIV infection, we assessed 27 cytokine levels released from PIV-infected human fetal lung fibroblasts. In addition, we examined relationships between these cytokine responses and signaling pathways (IκB kinase and p38 MAPK) in PIV-infected cells. At 24 h after infection, PIV-infected cells significantly released a number of cytokines, namely, proinflammatory cytokines [interleukins (IL)-1β, IL-6, and tumor necrosis factor-α], anti-inflammatory cytokine (IL-1ra), Th1 cytokines (interferon-γ, and IL-2), Th2 cytokines (IL-4, IL-5, and IL-10), granulopoiesis-inducing cytokines (granulocyte colony-stimulating factor and granulocyte–macrophage colony-stimulating factor), neutrophil recruitment-inducing cytokines (IL-8 and interferon-inducible protein-10), and eosinophil recruitment-inducing cytokines (eotaxin and regulated on activation normal T-cell expressed and secreted). PIV infection enhanced phosphorylation of both IκB and p38 MAPK, but not Akt, in the cells. Signaling pathway inhibitors, BMS-345541 (a specific IκB kinase inhibitor) and SB203580 (a specific p38 MAPK inhibitor), significantly suppressed release of these cytokines from PIV-infected cells. The results indicate that PIV infection induces aberrant production and release of various cytokines through IκB kinase and p38 MAPK pathways in human lung fibroblasts. Overproduction and imbalance of these cytokines may be partially associated with the pathophysiology of virus-induced asthma

    Ferromagnetism in multi--band Hubbard models: From weak to strong Coulomb repulsion

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    We propose a new mechanism which can lead to ferromagnetism in Hubbard models containing triangles with different on-site energies. It is based on an effective Hamiltonian that we derive in the strong coupling limit. Considering a one-dimensional realization of the model, we show that in the quarter-filled, insulating case the ground-state is actually ferromagnetic in a very large parameter range going from Tasaki's flat-band limit to the strong coupling limit of the effective Hamiltonian. This result has been obtained using a variety of analytical and numerical techniques. Finally, the same results are shown to apply away from quarter-filling, in the metallic case.Comment: 12 pages, revtex, 12 figures,needs epsf and multicol style file

    The Feature of Solitary Small Nodular Type of Hepatic Epithelioid Hemangioendothelioma

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    Hepatic epithelioid hemangioendothelioma (HEHE) is a rare tumor. Preoperative diagnosis of HEHE is difficult because it does not manifest specific symptoms or tumor markers. We report a resected case of small and solitary HEHE. The patient, a 74-year-old man, had undergone surgical resection for left renal cell carcinoma 20 years ago. During follow-up, a tumor approximately 1.3 cm in diameter was detected by computed tomography (CT) at liver segment VIII. It showed isodensity in the arterial phase, low density in the portal venous phase, and homogeneous enhancement in the late phase on CT and magnetic resonance imaging (MRI). We performed hepatic resection of the right hepatic vein drainage area. A pathological diagnosis of HEHE was made. Although small and solitary HEHE is rare, an enhancement pattern in each phase on CT and MRI, using contrast media, can yield clues for the diagnosis of HEHE

    The Association Between Documentation of Koplik Spots and Laboratory Diagnosis of Measles and Other Rash Diseases in a National Measles Surveillance Program in Japan

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    Koplik spots are considered a disease-specific sign for measles, although comprehensive virological studies have not been conducted to date. In Japan, a national survey of 3023 measles and measles-suspected cases was conducted between 2009 and 2014 using polymerase chain reaction (PCR) or reverse transcription PCR (RT-PCR) to detect various rash/fever-associated viruses. Koplik spots were observed in 717 of 3023 cases (23.7%). Among these, the measles virus was detected in 202 cases (28.2%), while the rubella virus was detected in 125 cases (17.4%). Other viruses were detected in 51 cases having the spots (7.1%). In some of the cases with spots, two or three viruses, such as the rubella virus, parvovirus, and human herpesvirus type 6 were also detected. The sensitivity and specificity of Koplik spots as a diagnostic marker for measles were 48 and 80%, respectively. The results suggested that Koplik spots might appear not only in measles but also in other viral infections, such as rubella, as a clinical sign

    Ultra-High-Resolution Computed Tomography of the Lung: Image Quality of a Prototype Scanner

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    Purpose: The image noise and image quality of a prototype ultra-high-resolution computed tomography (U-HRCT) scanner was evaluated and compared with those of conventional high-resolution CT (C-HRCT) scanners. Materials and Methods: This study was approved by the institutional review board. A U-HRCT scanner prototype with 0.25 mm × 4 rows and operating at 120 mAs was used. The C-HRCT images were obtained using a 0.5 mm × 16 or 0.5 mm × 64 detector-row CT scanner operating at 150 mAs. Images from both scanners were reconstructed at 0.1-mm intervals; the slice thickness was 0.25 mm for the U-HRCT scanner and 0.5 mm for the C-HRCT scanners. For both scanners, the display field of view was 80 mm. The image noise of each scanner was evaluated using a phantom. U-HRCT and C-HRCT images of 53 images selected from 37 lung nodules were then observed and graded using a 5-point score by 10 board-certified thoracic radiologists. The images were presented to the observers randomly and in a blinded manner. Results: The image noise for U-HRCT (100.87 ± 0.51 Hounsfield units [HU]) was greater than that for C-HRCT (40.41 ± 0.52 HU; P <.0001). The image quality of U-HRCT was graded as superior to that of C-HRCT (P <.0001) for all of the following parameters that were examined: margins of subsolid and solid nodules, edges of solid components and pulmonary ves sels in subsolid nodules, air bronchograms, pleural indentations, margins of pulmonary vessels, edges of bronchi, and interlobar fissures. Conclusion: Despite a larger image noise, the prototype U-HRCT scanner had a significantly better image quality than the C-HRCT scanners

    Relationships between Viral Load and the Clinical Course of COVID-19

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    To predict the clinical outcome of coronavirus disease-2019 (COVID-19), we examined relationships among epidemiological data, viral load, and disease severity. We examined viral loads of severe acute respiratory syndrome coronavirus type 2 (SARS-CoV-2) in fatal (15 cases), symptomatic/survived (133 cases), and asymptomatic cases (138 cases) using reverse transcription quantitative real-time PCR (RT-qPCR). We examined 5768 nasopharyngeal swabs (NPS) and attempted to detect the SARS-CoV-2 genome using RT-qPCR. Among them, the viral genome was detected using the method for the 370 NPS samples with a positive rate of 6.4%. A comparison of each age showed that the fatal case was higher than the survived case and asymptomatic patients. Survived cases were older than asymptomatic patients. Notably, the viral load in the fatal cases was significantly higher than in symptomatic or asymptomatic cases (p &lt; 0.05). These results suggested that a high viral load of the SARS-CoV-2 in elderly patients at an early stage of the disease results in a poor outcome. We should, therefore, intervene early to prevent a severe stage of the disease in such cases

    Correlation analysis of organ doses determined by Monte Carlo simulation with dose metrics for patients undergoing chest-abdomen-pelvis CT examinations

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    This study aimed to determine organ doses based on Monte Carlo (MC) simulations for individual patients undergoing routine adult chest abdomen-pelvis computed tomography (CT) examinations and to evaluate the correlations of organ doses with patient size and dose metrics. MC simulations were performed by reading detailed descriptions of the CT scanner, scanning parameters, and CT images of phantoms and patients into the simulation software. The simulation models were validated by comparing the simulated doses with the doses measured by in-phantom dosimetry using radiophotoluminescent glass dosimeters and an adult anthropomorphic phantom, and organ doses for 80 patients were determined from the simulation results. To obtain patient size and dose metrics, body mass index and volume computed tomography dose index (CTDIvol) data were collected. Water equivalent diameter (WED) was calculated from the CT images of each patient. Size-specific dose estimates (SSDE) were calculated using CTDIvol and average WED over the scan range, and organ specific SSDE were calculated using the average CTDIvol and WED over each organ position. The correlations of organ doses with dose metrics were evaluated using coefficients of determination.Organ doses increased with patient size, and the doses for obese were approximately two to three times higher than those for underweight patients. Organ doses exhibited stronger linear relationships with organ specific SSDE (R2 ≥ 0.82) than other dose metrics.The linear regression fits between organ doses determined by MC simulation and organ-specific SSDE are valuable for simplified and accurate organ dose estimation for individual patients undergoing CT examinations
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