114 research outputs found

    Regulation of hepatitis C virus secretion by the Hrs-dependent exosomal pathway

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    AbstractThe molecular mechanisms of assembly and budding of hepatitis C virus (HCV) remain poorly understood. The budding of several enveloped viruses requires an endosomal sorting complex required for transport (ESCRT), which is part of the cellular machinery used to form multivesicular bodies (MVBs). Here, we demonstrated that Hrs, an ESCRT-0 component, is critical for the budding of HCV through the exosomal secretion pathway. Hrs depletion caused reduced exosome production, which paralleled with the decrease of HCV replication in the host cell, and that in the culture supernatant. Sucrose-density gradient separation of the culture supernatant of HCV-infected cells revealed the co-existence of HCV core proteins and the exosome marker. Furthermore, both the core protein and an envelope protein of HCV were detected in the intraluminal vesicles of MVBs. These results suggested that HCV secretion from host cells requires Hrs-dependent exosomal pathway in which the viral assembly is also involved

    Optoelectronic properties and ultrafast carrier dynamics of copper iodide thin films

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    As a promising high mobility p-type wide bandgap semiconductor, copper iodide has received increasing attention in recent years. However, the defect physics/evolution are still controversial, and particularly the ultrafast carrier and exciton dynamics in copper iodide has rarely been investigated. Here, we study these fundamental properties for copper iodide thin films by a synergistic approach employing a combination of analytical techniques. Steady-state photoluminescence spectra reveal that the emission at ~420 nm arises from the recombination of electrons with neutral copper vacancies. The photogenerated carrier density dependent ultrafast physical processes are elucidated with using the femtosecond transient absorption spectroscopy. Both the effects of hot-phonon bottleneck and the Auger heating significantly slow down the cooling rate of hot-carriers in the case of high excitation density. The effect of defects on the carrier recombination and the two-photon induced ultrafast carrier dynamics are also investigated. These findings are crucial to the optoelectronic applications of copper iodide

    A sheep survived for 48 days with the biventricular bypass type total artificial heart.

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    A biventricular bypass type total artificial heart (BVB-TAH) utilizing two pusher-plate pumps was developed and implanted in a sheep for 48 days with excellent results. A Hall effect sensor was utilized to operate each pump independently with a full stroke at variable rates (VR). With this system, the animal's hemodynamics was kept physiologically, and all metabolic parameters except hemoglobin and hematocrit returned to normal three weeks after implantation. However, signs of infection appeared on the forty-second day, and consequently the animal fell into a state of shock. Even at that time the BVB-TAH maintained circulation by increasing pumping rate automatically. On the forty-eighth day, the animal could not stand and suffered from anuria; the experiment was then terminated after 1,140 h pumping. At autopsy, there was an enlarged heart with an atrophic change, 1,900 ml of pleural effusion, and 3,100ml of ascites fluid. Blood culture taken on the forty-seventh day yielded Acinetobacter calcoaceticus. The BVB-TAH operated in an independent VR mode maintained entire circulation, and has a capability of substituting the native heart function in any situation.</p

    Differences in K-ras and mitochondrial DNA mutations and microsatellite instability between colorectal cancers of Vietnamese and Japanese patients

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    [Background]:The incidence of early-onset (under 50 years of age) colorectal cancer (CRC) in the Vietnamese has been reported to be quite higher than that in the Japanese. To clarify the differences in genetic alterations between Vietnamese and Japanese CRCs, we investigated mutations in K-ras and mitochondrial DNA (mtDNA) and high-frequency microsatellite instability (MSI-H) in the CRCs of Vietnamese and Japanese patients. [Methods]:We enrolled 60 Vietnamese and 233 Japanese patients with invasive CRCs. DNA was extracted from formalin-fixed, paraffin-embedded tissue sections. K-ras mutations were examined with PCR-single-strand conformation polymorphism analysis. mtDNA mutations and MSI-H were examined with microsatellite analysis using D310 and BAT-26, respectively. [Results]:K-ras mutations were examined in 60 Vietnamese and 45 Japanese CRCs. The frequency of the mutations in the Vietnamese CRCs was significantly higher than that in the Japanese CRCs (8 of 24 [33%] vs 5 of 45 [11%], p =0.048). MSI-H was examined in 60 Vietnamese and 130 Japanese CRCs. The frequency of MSI-H in the Vietnamese CRCs was also significantly higher than that in the Japanese CRCs (6 of 27 [22%] vs 10 of 130 [8%], p =0.030). mtDNA mutations were examined in 60 Vietnamese and 138 Japanese CRCs. The frequency of mtDNA mutations in the Vietnamese CRCs was significantly higher than that in the Japanese CRCs (19 of 44 [43%] vs 11 of 133 [9%], p <0.001). There were no significant differences in clinicopathologic characteristics, such as age, sex, tumour location, and depth, in terms of tumours with/without each genetic alteration in the CRCs of the Vietnamese and Japanese patients. [Conclusions]:These results indicate that the developmental pathways of CRCs in the Vietnamese may differ from those of CRCs in the Japanese

    A Research on a New Science Curriculum Development Based on ‘Nature Of Science’ Ⅲ : Reconstruction of a Coherence Science Curriculum from Elementary School to Upper Secondary School

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    本研究は,新しい科学観を取り入れた小学校から高等学校までの理科カリキュラムを開発することを目的としており,今年度は3年次にあたる。これまでの成果と課題をもとに,初等・中等教育で一貫して「科学の本質」を学ぶためのフレームワーク構築に向け,小学校から高等学校を通じて系統的に取り扱うことが可能な内容について検討を行った。 中学校における実践からは,理科教師が,科学者コミュニティーによる知,政策決定者や教師たちによる教えるべき知,児童・生徒の発達段階や文脈などを考慮した教える知,について可能な限り熟知する必要があることが示唆された。また,論証活動を行う際の,教師の振る舞い方も重要であることも明らかとなった。 また,小学校における実践では,学年による差異はあるものの,見たことや考えたことの違いを次第に意識化させることによって,観察や実験等のレポートの書き方の指導にも繋がることが明らかとなった。 以上の実践より,科学の本質を初等・中等教育で一貫して教えるためには,これまでの実践の視点の変容に基づく教師による授業方略の在り方や投げ込み的教材を使用する教師の意図が,いかに重要であるかを示唆している。This study develops a new science curriculum for elementary to upper secondary schools which include the concept of the “Nature of Science”. We examined possible content to build a systematic framework for mentioned above science education. The practice at junior high school shows that teachers should be familiar with scholarly knowledge, knowledge to be taught by the policy makers and teachers, and taught knowledge which students understand through learning along with the students’ ages and contexts. The teacher’s behavior in argumentation by pupils is also important. The practice at elementary school shows that perceptions of the crucial distinction between inference and observation lead students to write good reports. These practices exemplify that teaching Nature of Science consistently to elementary and lower secondary students should largely depend on the teachers’ methods of instruction and what material they develop from a new viewpoint

    スポーツ傷害における情動的反応の傾向 ―性差に着目して―

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    In recent years, many problems related to sports injuries have been reported, among them suggestions of the tremendous burden and serious stress placed on an athlete’s psychology by receiving an injury. In addition to physical pain, pessimistic feelings of regret, anxiety, frustration, and inferiority occur, and occasionally render long term rehabilitation inevitable, ending an athlete’s lifestyle without being able to return to competitive life. According to a report published by the Ministry of Education, Culture, Sports, Science and Technology (1996), the incidence of sports injury among high school students is over 60%. However, a previously reported survey of female students at sports universities( 2008) demonstrated that 90% of athletes had in fact experienced injury. Furthermore, the results of the Diagnostic Inventory for Mental Health Pattern revealed that nearly 30% of those who had experienced sports injury were of the“ fatigue-type” demonstrating the exhaustion stage of stress, while nearly 20% were of the“ struggling-type” representing the stress resistance stage. If these stages are prolonged, they can impose a severe stress burden, affecting the efficacy of rehabilitation and possibly delaying recovery. These findings show that while correct medical treatment should be received as a matter of course, it is also necessary to simultaneously consider reducing psychological stress in order to achieve early recovery for sports injury and a return to competition. Therefore, the present study aimed to clarify the effects of injury on athlete psychology and to establish basic data to achieve early recovery
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