154 research outputs found

    Large-eddy simulation of turbulent open-channel flow with free-surface fluctuations

    Get PDF
    Proceedings of the Seventh International Conference on Hydroscience and Engineering, Philadelphia, PA, September 2006. http://hdl.handle.net/1860/732Large-eddy simulations of open-channel flows with free-surface fluctuations have been conducted. The conventional HSMAC algorithm of Hirt & Cook(1972) is extended to incorporate the calculation of the motion of the free surface within the iteration cycle for computing the pressure and the velocity using the kinematic and the dynamic conditions to be satisfied on the free surface. This method of computing a moving free surface has been verified in a benchmark of two-dimensional standing wave flow. For the sub-grid scale model, the standard Smagorinsky model with near-wall damping is used. Its performance is verified in a fully developed open-channel flow over a smooth flat bed at a laboratory Reynolds number. Subcritical flow past a sudden drop is then simulated and the results indicate that the mean velocity distribution can be predicted very well but the turbulent stresses need improvement

    Effect of quercetin on the permeability of N-acetyl 5-aminosalicylic acid on Caco-2 cells.

    Get PDF
    The aim of this study was to investigate the transporter-mediated transport of N-acetyl 5-aminosalicylic acid (Ac-5-ASA) and the effect of quercetin on Ac-5-ASA transport.Caco-2 cell monolayers grown in Transwells were used to study the transport of Ac-5-ASA in the absence or presence of quercetin, and apical-to-basolateral and basolateral-to-apical apparent permeability (PappAB and PappBA values, respectively) was determined. The effect of transporter inhibitors, such as MK571, quinidine and mitoxantrone, on the transport of Ac-5-ASA was investigated.In the absence of transporter mediators, the transport of Ac-5-ASA was much higher in the basolateral-to-apical direction than in the opposite direction. The PappBA/PappAB ratio of Ac-5-ASA was 4.89. Quercetin inhibited the apical efflux of Ac-5-ASA and decreased the PappBA/PappAB ratio to 1.05. Of the transporter inhibitors, MK571 decreased the PappBA/PappAB ratio to 1.07; however, neither quinidine nor mitoxantrone had an effect on Ac-5-ASA transport.Ac-5-ASA was excreted by multidrug resistance-associated protein 2 from Caco-2 cells, and its transport was inhibited by quercetin. Our findings suggest that dose levels of sulfasalazine or 5-aminosalicylic acid can be decreased by coadministration of quercetin, leading to improved pharmaceutical care for inflammatory bowel diseases.The aim of this study was to investigate the transporter-mediated transport of N-acetyl 5-aminosalicylic acid (Ac-5-ASA) and the effect of quercetin on Ac-5-ASA transport.Caco-2 cell monolayers grown in Transwells were used to study the transport of Ac-5-ASA in the absence or presence of quercetin, and apical-to-basolateral and basolateral-to-apical apparent permeability (PappAB and PappBA values, respectively) was determined. The effect of transporter inhibitors, such as MK571, quinidine and mitoxantrone, on the transport of Ac-5-ASA was investigated.In the absence of transporter mediators, the transport of Ac-5-ASA was much higher in the basolateral-to-apical direction than in the opposite direction. The PappBA/PappAB ratio of Ac-5-ASA was 4.89. Quercetin inhibited the apical efflux of Ac-5-ASA and decreased the PappBA/PappAB ratio to 1.05. Of the transporter inhibitors, MK571 decreased the PappBA/PappAB ratio to 1.07; however, neither quinidine nor mitoxantrone had an effect on Ac-5-ASA transport.Ac-5-ASA was excreted by multidrug resistance-associated protein 2 from Caco-2 cells, and its transport was inhibited by quercetin. Our findings suggest that dose levels of sulfasalazine or 5-aminosalicylic acid can be decreased by coadministration of quercetin, leading to improved pharmaceutical care for inflammatory bowel diseases

    Atypical Lipomatous Tumor of the Tongue:Report of a Case

    Get PDF
    The term atypical lipomatous tumor (ALT) is synonymous with well-differentiated liposarcoma (WDL). This tumor occurs very rarely in the tongue. Thus, it is difficult to predict its prognosis. Although recurrence of ALT/WDL is thought to be unlikely after complete excision, long-term follow-up is necessary when considering the pathologic conditions of this tumor at other sites. Here, we report a case of an ALT of the tongue, with a review of the literature. A 68-year-old man was referred to our hospital because of a tumor on the left side of his tongue. Upon palpation, the tumor was 12mm in diameter, circumscribed, elastic and hard, well demarcated, movable, and painless. We diagnosed the lesion as a lipoma and extirpated the tumor under local anesthesia. Because the specimen was histopathologically diagnosed as an ALT, as a precaution, we excised an additional 5mm from the area surrounding the original tumor under general anesthesia. Three years after the operation, the tongue demonstrated good healing without paresthesia or dysfunction, and to date there has been no evidence of recurrence

    Wide dynamic range charge sensor operation by high-speed feedback control of radio-frequency reflectometry

    Full text link
    Semiconductor quantum dots are useful for controlling and observing quantum states and can also be used as sensors for reading out quantum bits and exploring local electronic states in nanostructures. However, challenges remain for the sensor applications, such as the trade-off between sensitivity and dynamic range and the issue of instability due to external disturbances. In this study, we demonstrate proportional-integral-differential feedback control of the radio-frequency reflectometry in GaN nanodevices using a field-programmable gate array. This technique can maintain the operating point of the charge sensor with high sensitivity. The system also realizes a wide dynamic range and high sensor sensitivity through the monitoring of the feedback signal. This method has potential applications in exploring dynamics and instability of electronic and quantum states in nanostructures.Comment: 13 pages, 5 figure

    Channel length dependence of the formation of quantum dots in GaN/AlGaN FETs

    Full text link
    Quantum dots can be formed in simple GaN/AlGaN field-effect-transistors (FETs) by disordered potential induced by impurities and defects. Here, we investigate the channel length dependence of the formation of quantum dots. We observe decrease of the number of formed quantum dots with decrease of the FET channel length. A few quantum dots are formed in the case with the gate length of 0.05~μ\mu m and we evaluate the dot parameters and the disordered potential. We also investigate the effects of a thermal cycle and illumination of light, and reveal the change of the disordered potential.Comment: 10 pages, 5 figure

    Human Molecular Chaperone Hsp60 and Its Apical Domain Suppress Amyloid Fibril Formation of α-Synuclein

    Get PDF
    Heat shock proteins play roles in assisting other proteins to fold correctly and in preventing the aggregation and accumulation of proteins in misfolded conformations. However, the process of aging significantly degrades this ability to maintain protein homeostasis. Consequently, proteins with incorrect conformations are prone to aggregate and accumulate in cells, and this aberrant aggregation of misfolded proteins may trigger various neurodegenerative diseases, such as Parkinson’s disease. Here, we investigated the possibilities of suppressing α-synuclein aggregation by using a mutant form of human chaperonin Hsp60, and a derivative of the isolated apical domain of Hsp60 (Hsp60 AD(Cys)). In vitro measurements were used to detect the effects of chaperonin on amyloid fibril formation, and interactions between Hsp60 proteins and α-synuclein were probed by quartz crystal microbalance analysis. The ability of Hsp60 AD(Cys) to suppress α-synuclein intracellular aggregation and cytotoxicity was also demonstrated. We show that Hsp60 mutant and Hsp60 AD(Cys) both effectively suppress α-synuclein amyloid fibril formation, and also demonstrate for the first time the ability of Hsp60 AD(Cys) to function as a mini-chaperone inside cells. These results highlight the possibility of using Hsp60 AD as a method of prevention and treatment of neurodegenerative diseases

    FADDのリン酸化の状態と根治的前立腺全摘除術後の生化学的再発は関連する

    Get PDF
    OBJECTIVE: To assess whether the phosphorylated Fas-associated death domain protein (FADD) at 194 serine (p-FADD) is valuable as a marker of biochemical recurrence in hormone-naive patients who had undergone radical prostatectomy. MATERIALS AND METHODS: We used radical prostatectomy specimens from 106 patients. None of the patients had received neoadjuvant or adjuvant therapy. The percentage of positive p-FADD cells (nuclear staining) was immunohistochemically evaluated. The correlation between FADD phosphorylation and the clinicopathologic parameters was assessed. The correlation between the biochemical recurrence-free rate and the p-FADD expression level was analyzed using the Kaplan-Meier method. RESULTS: Overall, 39 patients developed biochemical recurrence. We investigated the expression of p-FADD in 106 patients with prostate cancer using immunohistochemistry. We compared our findings with the clinicopathologic parameters, including the follow-up data. Patients with a greater positive p-FADD rate had a significantly lower biochemical recurrence rate than those with a lower positive p-FADD rate (P < .001). A significant inverse correlation was found between the positive p-FADD rate and the Gleason score. CONCLUSION: A low expression of p-FADD could be a predictor of biochemical recurrence in hormone-naive patients who have undergone radical prostatectomy.博士(医学)・乙第1313号・平成25年5月29

    Population pharmacokinetic modeling of GS‐441524, the active metabolite of remdesivir, in Japanese COVID‐19 patients with renal dysfunction

    Get PDF
    腎障害患者におけるレムデシビルの薬物動態モデルを構築 --新型コロナウイルス感染症治療薬の適正使用に向けて--. 京都大学プレスリリース. 2021-11-25.Remdesivir, a prodrug of the nucleoside analog GS-441524, plays a key role in the treatment of coronavirus disease 2019 (COVID-19). However, owing to limited information on clinical trials and inexperienced clinical use, there is a lack of pharmacokinetic (PK) data in patients with COVID-19 with special characteristics. In this study, we aimed to measure serum GS-441524 concentrations and develop a population PK (PopPK) model. Remdesivir was administered at a 200 mg loading dose on the first day followed by 100 mg from day 2, based on the package insert, in patients with an estimated glomerular filtration rate (eGFR) greater than or equal to 30 ml/min. In total, 190 concentrations from 37 Japanese patients were used in the analysis. The GS-441524 trough concentrations were significantly higher in the eGFR less than 60 ml/min group than in the eGFR greater than or equal to 60 ml/min group. Extracorporeal membrane oxygenation in four patients hardly affected the total body clearance (CL) and volume of distribution (Vd) of GS-441524. A one-compartment model described serum GS-441524 concentration data. The CL and Vd of GS-441524 were significantly affected by eGFR readjusted by individual body surface area and age, respectively. Simulations proposed a dose regimen of 200 mg on day 1 followed by 100 mg once every 2 days from day 2 in patients with an eGFR of 30 ml/min or less. In conclusion, we successfully established a PopPK model of GS-441524 using retrospectively obtained serum GS-441524 concentrations in Japanese patients with COVID-19, which would be helpful for optimal individualized therapy of remdesivir

    Checklist of vascular plants of Kui Block Field, Mihara City, Hiroshima Prefecture, Japan

    Get PDF
    広島県三原市久井町に位置する久井岩海は国の天然記念物に指定されている。今回,久井岩海の天然記念物調査に際し,維管束植物(シダ植物,裸子植物,被子植物)のフロラの見直しを行う機会を得た。本稿では,標本および文献にもとづいて久井岩海および周辺地域の維管束植物フロラをまとめた。その結果,維管束植物合計415種(ヒカゲノカズラ植物1種と狭義シダ植物36種,裸子植物6種,被子植物372種。ただし,種以下の下位分類群や雑種は種として数えた)が生育していることが確認された。Kui Block Field, Mihara City, Hiroshima Prefecture, SW Japan is designated as a national natural monument. In this study, a checklist of the vascular plants recorded from Kui Block Field is provided, based on previous publications, herbarium specimens and our recent investigations. 415 species of vascular plants are recorded, consisting of 1 species of lycopods, 36 species of pteridophytes, 6 species of gymnosperms, and 372 species of angiosperms
    corecore