128 research outputs found

    Development of a Novel Reformer for Tar-free Syngas Production

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    AbstractA novel reformer using highly efficient heat regeneration for tar-free syngas production is developed and its performance demonstrated in a pilot-scale plant using steam gasification. Basic design parameters of the regenerative tar reformer, namely residence time and amount of oxidant are determined based on numerical results. It has been predicted that good performance could be achieved at an operation temperature about 1573K, the residence time exceeding 4sec and an oxidant addition of 12% of the syngas flow rate. The regenerative tar reformer so designed shows stable operation. Over 99% of light and heavy tars are reformed to gas in the case of 11.3% oxygen addition to syngas. Further it is seen that a reduction of oxygen consumption more than 30% compared to a conventional oxidation reformer can be achieved. The formation of a high temperature zone has a strong influence on the tar reforming efficiency

    Emergence of quantum critical behavior in metallic quantum-well states of strongly correlated oxides

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    Controlling quantum critical phenomena in strongly correlated electron systems, which emerge in the neighborhood of a quantum phase transition, is a major challenge in modern condensed matter physics. Quantum critical phenomena are generated from the delicate balance between long-range order and its quantum fluctuation. So far, the nature of quantum phase transitions has been investigated by changing a limited number of external parameters such as pressure and magnetic field. We propose a new approach for investigating quantum criticality by changing the strength of quantum fluctuation that is controlled by the dimensional crossover in metallic quantum well (QW) structures of strongly correlated oxides. With reducing layer thickness to the critical thickness of metal-insulator transition, crossover from a Fermi liquid to a non-Fermi liquid has clearly been observed in the metallic QW of SrVO3_3 by \textit{in situ} angle-resolved photoemission spectroscopy. Non-Fermi liquid behavior with the critical exponent α=1{\alpha} = 1 is found to emerge in the two-dimensional limit of the metallic QW states, indicating that a quantum critical point exists in the neighborhood of the thickness-dependent Mott transition. These results suggest that artificial QW structures provide a unique platform for investigating novel quantum phenomena in strongly correlated oxides in a controllable fashion.Comment: 6 pages, 3 figure

    The Prevalence and Characteristics of Older Japanese Adults with Polypharmacy, Based on Regionally Representative Health Insurance Claims Data

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    We aimed to clarify the prevalence of polypharmacy among elderly individuals in Japan. We used the data obtained from a large-scale population-based representative database of health insurance claims in a single prefecture in Japan. We examined all of the outpatient and pharmaceutical health insurance claims for National Health Insurance and those for Late-stage Elderly Health Insurance in Nagasaki Prefecture, Japan between April and June 2016. When two or more claim forms were issued for a patient in a single month, we combined the data and identified the number of prescribed drugs for each person. The definition of polypharmacy is a the prescription of six or more drugs per month. We investigated the prevalence of polypharmacy among the beneficiaries of the two insurance systems. Of the 605,406 beneficiaries of the 2 insurance systems, 121,033 (20.0%) patients with polypharmacy were identified. The prevalence of polypharmacy increased with age, especially among the beneficiaries aged > 85 years, with about half of the beneficiaries having polypharmacy status. About half of the people aged > 85 years in the database had polypharmacy status. When a drug is prescribed to an elderly individual, it is necessary to consider the possibility of polypharmacy-related problems

    Immunology and Inflammation

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    In the thymus, the thymic epithelium provides a microenvironment essential for the development of functionally competent and self-tolerant T cells. Previous findings showed that modulation of Wnt/β-catenin signaling in mouse thymic epithelial cells (TECs) disrupts embryonic thymus organogenesis. However, the role of β-catenin in TECs for postnatal T-cell development remains to be elucidated. Here, we analyzed gain-of-function (GOF) and loss-of-function (LOF) of β-catenin highly specific in mouse TECs. We found that GOF of β-catenin in TECs results in severe thymic dysplasia and T-cell deficiency beginning from the embryonic period. By contrast, LOF of β-catenin in TECs reduces the number of cortical TECs and thymocytes modestly and only postnatally. These results indicate that fine-tuning of β-catenin expression within a permissive range is required for TECs to generate an optimal microenvironment to support postnatal T-cell development

    Prognostic Factors for Recurrence after Tegafur-uracil Plus Leucovorin Adjuvant Chemotherapy in Patients with Colorectal Cancer 

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    To evaluate prognostic factors for recurrence after tegafur-uracil plus leucovorin (UFT/LV) adjuvant chemotherapy in patients with colorectal cancer (CRC). Consecutive patients with CRC who received UFT/LV as adjuvant chemotherapy at Showa University Hospital between June 2005 and December 2008 were included in the study, 5-year disease-free survival (DFS) and overall survival (OS) rates were estimated, and prognostic factors for recurrence were analyzed using the Cox proportional hazards model for multivariate analysis. Of 92 patients included in the study, 17 (18.5%) had disease recurrence. The 5-year DFS and OS rates were 82.2% and 91.9%, respectively. In the multivariate analysis, preoperative CA19-9 level>37U/ml, emergency operation, and T4 lesions were independent significant prognostic factors after treatment with UFT/LV adjuvant chemotherapy. The three independent prognostic factors —T4 lesions, emergency operation, and high preoperative CA19-9 levels— may be useful for decision-making regarding whether patients should receive 5-fluouracil-based or L-oxaliplatin-based adjuvant chemotherapy. As this was a single-institution study with a small number of patients, our findings need to be confirmed in larger multicenter studies

    Isolated gestational proteinuria preceding the diagnosis of preeclampsia : an observational study

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    Introduction. Some pregnant women develop significant proteinuria in the absence of hypertension. However, clinical significance of isolated gestational proteinuria (IGP) is not well understood. This study aimed to determine the prevalence of IGP in singleton pregnancies and the proportion of women with IGP who subsequently developed preeclampsia (IGP-PE) among all PE cases. Material and methods. This was an observational study of 6819 women with singleton pregnancies at 12 centers, including 938 women with at least once determination of protein-to-creatinine ratio (P/Cr). Significant proteinuria in pregnancy (SPIP) was defined as P/Cr (mg/mg) level >0.27. IGP was defined as SPIP in the absence of hypertension. Gestational hypertension (GH) preceding preeclampsia (GH-PE) was defined as preeclampsia (PE) in which GH preceded SPIP. Simultaneous PE (S-PE) was defined as PE in which both SPIP and hypertension occurred simultaneously. Results. IGP and PE were diagnosed in 130 (1.9%) and 158 (2.3%) of 6819 women, respectively. Of 130 women with IGP, 32 (25%) progressed to PE and accounted for 20% of all women with PE. Hence, women with IGP had a relative risk of 13.1 (95% CI; 9.2-18.5) for developing PE compared with those without IGP [25% (32/130) vs. 1.9% (126/6689)]. At diagnosis of SPIP, P/Cr levels already exceeded 1.0 more often in women with S-PE than in those with IGP-PE [67% (33/49) vs. 44% (14/32), respectively, p = 0.031]. Conclusions. IGP is a risk factor for PE, and IGP-PE accounts for a considerable proportion (20%) of all PE

    FGF2 Has Distinct Molecular Functions from GDNF in the Mouse Germline Niche

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    Both glial cell line-derived neurotrophic factor (GDNF) and fibroblast growth factor 2 (FGF2) are bona fide self-renewal factors for spermatogonial stem cells, whereas retinoic acid (RA) induces spermatogonial differentiation. In this study, we investigated the functional differences between FGF2 and GDNF in the germline niche by providing these factors using a drug delivery system in vivo. Although both factors expanded the GFRA1+ subset of undifferentiated spermatogonia, the FGF2-expanded subset expressed RARG, which is indispensable for proper differentiation, 1.9-fold more frequently than the GDNF-expanded subset, demonstrating that FGF2 expands a differentiation-prone subset in the testis. Moreover, FGF2 acted on the germline niche to suppress RA metabolism and GDNF production, suggesting that FGF2 modifies germline niche functions to be more appropriate for spermatogonial differentiation. These results suggest that FGF2 contributes to induction of differentiation rather than maintenance of undifferentiated spermatogonia, indicating reconsideration of the role of FGF2 in the germline niche
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