61 research outputs found

    Evidence-based Tool for Triggering School Closures during Influenza Outbreaks, Japan

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    Guidelines available to school administrators to support school closure decisions during influenza outbreaks are usually not evidence-based. Using empirical data on absentee rates of elementary school students in Japan, we developed a simple and practical algorithm for determining the optimal timing of school closures for control of influenza outbreaks

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

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    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

    A speciation gene for left–right reversal in snails results in anti-predator adaptation

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    How speciation genes can spread in a population is poorly understood. In land snails, a single gene for left–right reversal could be responsible for instant speciation, because dextral and sinistral snails have difficulty in mating. However, the traditional two-locus speciation model predicts that a mating disadvantage for the reversal should counteract this speciation. In this study, we show that specialized snake predation of the dextral majority drives prey speciation by reversal. Our experiments demonstrate that sinistral Satsuma snails (Stylommatophora: Camaenidae) survive predation by Pareas iwasakii (Colubroidea: Pareatidae). Worldwide biogeography reveals that stylommatophoran snail speciation by reversal has been accelerated in the range of pareatid snakes, especially in snails that gain stronger anti-snake defense and reproductive isolation from dextrals by sinistrality. Molecular phylogeny of Satsuma snails further provides intriguing evidence of repetitive speciation under snake predation. Our study demonstrates that a speciation gene can be fixed in populations by positive pleiotropic effects on survival

    Flicker Suppression of AC Driven White LED by Yellow Persistent Phosphor of Ce³⁺-Cr³⁺ Co-doped Garnet

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    The alternative current driven light emitting diode (AC-LED) lighting system has attracted a great deal of attention because of the high luminous efficiency and the simple electric circuit. However, this system causes the unacceptable flicker due to rapid fluctuations in the voltage of the power supply. In order to compensate the flicker effect in AC-LED, we proposed the use of yellow persistent luminescent garnet phosphors. The time evolution of luminescence intensity measurement of Ce³⁺-Cr³⁺ co-doped Gd₃Al₂Ga₃O₁₂ phosphor is calculated and showed to be about 60%. This result demonstrated that persistent phosphor is expected to solve the problem of flicker caused in AC-driven LED lighting system

    Effective Ratiometric Luminescent Thermal Sensor by Cr3+-Doped Mullite Bi2Al4O9 with Robust and Reliable Performances

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    The design of effective optical systems featuring high thermal sensitivity able to discriminate ever smaller variations of temperature in noncontact mode is of critical importance to face the challenges brought by the modern-day technological revolution. If from one hand, the ratiometric optical thermometers based on Boltzmann distribution are demonstrated to be characterized by a unique reliability, on the other hand, robust performances in different environments are highly desired for new applications such as in situ thermal sensing of catalytic reactions. Here, the crystal field experienced by Cr3+ in Bi2Al4O9 is investigated demonstrating the potential of this system as ratiometric self-referencing thermal sensor being characterized by high relative sensitivity (1.24% K−1 at 290 K). The remarkable absolute sensitivity results in an exceptional low thermal resolution of ≈0.2 K, 15-fold lower than for the conventional Nd3+-based thermometers used in biological applications. The comparison of the performances among different systems evidences the potential of Cr3+-based thermometers with thermal resolution even lower than the state of the art diamond. In addition, the pH dependence of the photoluminescence emission confirms a high stability also at extreme conditions of basic and acid environments and the aging effects are tested for one week
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