135 research outputs found

    The Speed–Density Relationship: Road Traffic Flow Analysis with Spatial Panel Data

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    In this paper, we focus on the fundamental speed–density relationship of aggregated vehicular traffic flow in the entire urban area. We use aggregated observations on routes that are treated as cross-section units in three time intervals and examine the speed–density relationship. We consider a variety of routes and road networks for our spatial panel data analysis. We apply the estimator of Kelejian and Prucha (1999) to the usual panel data case, based on certain restrictions on the evolution of spatial dependence over time

    Salmonella osteomyelitis of the distal radius in a healthy young adult patient : Report of a rare case and literature review

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    Salmonella osteomyelitis of the radius in a healthy individual is very rare. We present such a case involving the distal radius of a healthy 23-year-old man without underlying disease or possible episode. He had right wrist pain for approximately 3 years, and osteolytic lesion was seen in the right distal radius. He underwent surgical treatment, and salmonella was isolated from pus in the lesion. Postoperative antibiotics successfully treated his infection. He had no sign of recurrence, but the point of entry for infection remains unknown

    Pressure-induced anomalous valence crossover in cubic YbCu5-based compounds

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    A pressure-induced anomalous valence crossover without structural phase transition is observed in archetypal cubic YbCu5 based heavy Fermion systems. The Yb valence is found to decrease with increasing pressure, indicating a pressure-induced crossover from a localized 4f (13) state to the valence fluctuation regime, which is not expected for Yb systems with conventional c-f hybridization. This result further highlights the remarkable singularity of the valence behavior in compressed YbCu5-based compounds. The intermetallics Yb2Pd2Sn, which shows two quantum critical points (QCP) under pressure and has been proposed as a potential candidate for a reentrant Yb(2+) state at high pressure, was also studied for comparison. In this compound, the Yb valence monotonically increases with pressure, disproving a scenario of a reentrant non-magnetic Yb(2+) state at the second QCP

    Electronic structure of Kondo lattice compounds YbNi3X9 (X = Al, Ga) studied by hard x-ray spectroscopy

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    We have performed hard x-ray photoemission spectroscopy (HAXPES) for Yb-based Kondo lattice compounds; an antiferromagnetic heavy-fermion system YbNi3Al9 and a valence fluctuation system YbNi3Ga9. The Yb 3d5/2 spectra of YbNi3Ga9 showed both Yb2+ and Yb3+-derived structures indicating strong valence fluctuation, and the intensity of Yb2+ (Yb3+) structures gradually increased (decreased) on cooling. The Yb 3d5/2 spectra of YbNi3Al9 mostly consisted of Yb3+-derived structures and showed little temperature dependence. The Yb valences of YbNi3Ga9 and YbNi3Al9 at 22 K were evaluated to be 2.43 and 2.97, respectively. Based on the results of the Ni 2p and valence-band HAXPES spectra together with soft x-ray valence-band spectra, we described that the difference of physical properties of YbNi3X9 (X= Al, Ga) is derived from the differences of the 4f-hole level relative to the Fermi level (EF) and Ni 3d density of states at EF. The HAXPES results on the Yb valences were consistent with those obtained by x-ray absorption spectroscopy using the partial fluorescence yield mode and resonant x-ray emission spectroscopy at the Yb L3 edge

    Cricotracheostomy for patients with severe COVID-19: A case control study

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    BackgroundTracheostomy is an important procedure for the treatment of severe coronavirus disease-2019 (COVID-19). Older age and obesity have been reported to be associated with the risk of severe COVID-19 and prolonged intubation, and anticoagulants are often administered in patients with severe COVID-19; these factors are also related to a higher risk of tracheostomy. Cricotracheostomy, a modified procedure for opening the airway through intentional partial cricoid cartilage resection, was recently reported to be useful in cases with low-lying larynx, obesity, stiff neck, and bleeding tendency. Here, we investigated the usefulness and safety of cricotracheostomy for severe COVID-19 patients.Materials and methodsFifteen patients with severe COVID-19 who underwent cricotracheostomy between January 2021 and April 2022 with a follow-up period of ≥ 14 days were included in this study. Forty patients with respiratory failure not related to COVID-19 who underwent traditional tracheostomy between January 2015 and April 2022 comprised the control group. Data were collected from medical records and comprised age, sex, body mass index, interval from intubation to tracheostomy, use of anticoagulants, complications of tracheostomy, and decannulation.ResultsAge, sex, and days from intubation to tracheostomy were not significantly different between the COVID-19/cricotracheostomy and control/traditional tracheostomy groups. Body mass index was significantly higher in the COVID-19 group than that in the control group (P = 0.02). The rate of use of anticoagulants was significantly higher in the COVID-19 group compared with the control group (P < 0.01). Peri-operative bleeding, subcutaneous emphysema, and stomal infection rates were not different between the groups, while stomal granulation was significantly less in the COVID-19 group (P = 0.04).ConclusionsThese results suggest that cricotracheostomy is a safe procedure in patients with severe COVID-19

    Clonal hematopoiesis in adult pure red cell aplasia

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    Idiopathic pure red cell aplasia (PRCA) and secondary PRCA associated with thymoma and large granular lymphocyte leukemia are generally considered to be immune-mediated. The PRCA2004/2006 study showed that poor responses to immunosuppression and anemia relapse were associated with death. PRCA may represent the prodrome to MDS. Thus, clonal hematopoiesis may be responsible for treatment failure. We investigated gene mutations in myeloid neoplasm-associated genes in acquired PRCA. We identified 21 mutations affecting amino acid sequences in 11 of the 38 adult PRCA patients (28.9%) using stringent filtering of the error-prone sequences and SNPs. Four PRCA patients showed 7 driver mutations in TET2, DNMT3A and KDM6A, and 2 PRCA patients carried multiple mutations in TET2. Five PRCA patients had mutations with high VAFs exceeding 0.3. These results suggest that clonal hematopoiesis by stem/progenitor cells might be related to the pathophysiology of chronic PRCA in certain adult patients
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