77 research outputs found
三陸沿岸域に来遊するアオウミガメ(Chelonia mydas)の採餌生態に関する研究
学位の種別: 課程博士審査委員会委員 : (主査)東京大学教授 佐藤 克文, 東京大学教授 大竹 二雄, 東京大学教授 青山 潤, 東京大学准教授 北川 貴士, 岡山理科大学教授 亀崎 直樹University of Tokyo(東京大学
High resting metabolic rates with low thermal dependence induce active dives in overwintering Pacific juvenile loggerhead turtles
UTokyo FOCUS Articles掲載「三陸のウミガメは寒冷地仕様 高い休止代謝速度と低い温度依存性によって冬季でも活動性を維持」https://www.u-tokyo.ac.jp/focus/ja/articles/a_00627.htmlUTokyo FOCUS Articles "Cold never bothered me anyway Pacific sea turtles\u27 metabolisms stay active over winter" https://www.u-tokyo.ac.jp/focus/en/articles/z0508_00003.htm
Exosome-Based Molecular Transfer Activity of Macrophage-Like Cells Involves Viability of Oral Carcinoma Cells: Size Exclusion Chromatography and Concentration Filter Method
Extracellular vesicles (EV) heterogeneity is a crucial issue in biology and medicine. In addition, tumor-associated macrophages are key components in cancer microenvironment and immunology. We developed a combination method of size exclusion chromatography and concentration filters (SEC-CF) and aimed to characterize different EV types by their size, cargo types, and functions. A human monocytic leukemia cell line THP-1 was differentiated to CD14-positive macrophage-like cells by stimulation with PMA (phorbol 12-myristate 13-acetate) but not M1 or M2 types. Using the SEC-CF method, the following five EV types were fractionated from the culture supernatant of macrophage-like cells: (i) rare large EVs (500-3000 nm) reminiscent of apoptosomes, (ii) EVs (100-500 nm) reminiscent of microvesicles (or microparticles), (iii) EVs (80-300 nm) containing CD9-positive large exosomes (EXO-L), (iv) EVs (20-200 nm) containing unidentified vesicles/particles, and (v) EVs (10-70 nm) containing CD63/HSP90-positive small exosomes (EXO-S) and particles. For a molecular transfer assay, we developed a THP-1-based stable cell line producing a GFP-fused palmitoylation signal (palmGFP) associated with the membrane. The THP1/palmGFP cells were differentiated into macrophages producing palmGFP-contained EVs. The macrophage/palmGFP-secreted EXO-S and EXO-L efficiently transferred the palmGFP to receiver human oral carcinoma cells (HSC-3/palmTomato), as compared to other EV types. In addition, the macrophage-secreted EXO-S and EXO-L significantly reduced the cell viability (ATP content) in oral carcinoma cells. Taken together, the SEC-CF method is useful for the purification of large and small exosomes with higher molecular transfer activities, enabling efficient molecular delivery to target cells
Spontaneous cervicocephalic arterial dissection with headache and neck pain as the only symptom
長期間の多職種連携による離床
Early mobilization is an effective way to improve the physical function of critically ill patients, but there are numerous barriers to mobilization. One such is an early ward transfer. Mobilization is often insufficient in a ward, and the patient cannot be liberated from mechanical ventilation. We experienced a case of a successfully liberated patient from prolonged mechanical ventilation in long-term mobilization as orchestrated by a multidisciplinary team in the ICU. A 45-year-old female was admitted to the ICU and placed on mechanical ventilation for acute respiratory distress syndrome(ARDS). We deployed a mobilization protocol, which was mostly restricted to passive exercise in the first 2 weeks after admission. On day 30, the patient recovered from unstable respiration, but could not be liberated from mechanical ventilation because of muscle weakness, diagnosed as ICU-acquired weakness. The patient was gradually mobilized and transferred to a chair on day 35, and she was able to stand on day 56. On day 65, she was completely liberated from mechanical ventilation and discharged from the ICU 70 days after her initial admission. Long-term mobilization is important for liberation of a patient from prolonged mechanical ventilation as well as early mobilization in the ICU
Ocean observations in support of studies and forecasts of tropical and extratropical cyclones
© The Author(s), 2019. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in
Domingues, R., Kuwano-Yoshida, A., Chardon-Maldonado, P., Todd, R. E., Halliwell, G., Kim, H., Lin, I., Sato, K., Narazaki, T., Shay, L. K., Miles, T., Glenn, S., Zhang, J. A., Jayne, S. R., Centurioni, L., Le Henaff, M., Foltz, G. R., Bringas, F., Ali, M. M., DiMarco, S. F., Hosoda, S., Fukuoka, T., LaCour, B., Mehra, A., Sanabia, E. R., Gyakum, J. R., Dong, J., Knaff, J. A., & Goni, G. Ocean observations in support of studies and forecasts of tropical and extratropical cyclones. Frontiers in Marine Science, 6, (2019): 446, doi:10.3389/fmars.2019.00446.Over the past decade, measurements from the climate-oriented ocean observing system have been key to advancing the understanding of extreme weather events that originate and intensify over the ocean, such as tropical cyclones (TCs) and extratropical bomb cyclones (ECs). In order to foster further advancements to predict and better understand these extreme weather events, a need for a dedicated observing system component specifically to support studies and forecasts of TCs and ECs has been identified, but such a system has not yet been implemented. New technologies, pilot networks, targeted deployments of instruments, and state-of-the art coupled numerical models have enabled advances in research and forecast capabilities and illustrate a potential framework for future development. Here, applications and key results made possible by the different ocean observing efforts in support of studies and forecasts of TCs and ECs, as well as recent advances in observing technologies and strategies are reviewed. Then a vision and specific recommendations for the next decade are discussed.This study was supported by the National Oceanic and Atmospheric Administration and JSPS KAKENHI (Grant Numbers: JP17K19093, JP16K12591, and JP16H01846)
Effect of Lewis acid on catalytic dehydration of a chitin-derived sugar alcohol
Chitin is an abundant marine biomass consisting of N-acetylglucosamine (NAG) units. NAG is a source for 2-acetamide-2-deoxyisosorbide (ADI), a condensed five-membered ring compound potentially useful for producing nitrogen-containing polymers. The synthetic route of ADI from NAG consists of hydrogenation of NAG to 2-acetamide-2-deoxysorbitol (ADS) by a supported metal catalyst and subsequent dehydration reaction by a BrOnsted acid catalyst. However, the dehydration step has remained a challenge due to low reactivity of the substrate and low selectivity. Here, we report a combination of BrOnsted acid and Lewis acid catalysts for accelerating the ADS dehydration. The additional use of a catalytic amount of ytterbium triflate in the ADS dehydration by trifluoromethanesulfonic acid catalyst shortens the reaction time by one third and moreover increases the yield of ADI by changing regio-selectivity of the reaction. Mechanistic roles of the ytterbium complex are discussed based on the experimental evidences and density functional theory calculations
Characteristic activity of phosphorous acid in the dehydration condensation of a chitin-derived nitrogen-containing sugar alcohol
Chitin is a potential resource for the production of renewable organonitrogen compounds, as it contains biologically fixed nitrogen. Hydrolysis of chitin followed by hydrogenation gives the sugar alcohol named 2-acetamido-2-deoxysorbitol (ADS). The dehydration condensation of ADS produces 2-acetamido-2-deoxyisosorbide (ADI), which is a prospective precursor of nitrogen-containing polymers. However, the conversion of ADS to ADI in previous works needed a large amount of CF3SO3H as a superstrong acid catalyst, which is high cost and requires special corrosion-resistant equipment. In this work, we have found that H3PO3, a weak acid, can convert ADS to ADI. Possibly, H3PO3 alters the reaction mechanism from a simple acid-catalysed dehydration cyclisation to a cyclisation via phosphite esters. Density functional theory calculations suggest that the modified pathway via the phosphite esters significantly reduces the activation energy. In addition, the reducing ability of the acid likely decreases the formation of condensation by-products
Antiferromagnetic ordering and estimation of the exchange interaction in the π-d system λ-(BEDSe-TTF)2FeCl4 studied using 13C NMR
We performed 13C NMR measurements on lambda-(BEDSe-TTF)2FeCl4[BEDSe-TTF = bis(ethylenediseleno) tetrathiafulvalene] to investigate the antiferromagnetic transition in this material and evaluate the exchange interaction J pi d between the donor molecules and FeCl-4 anions. Based on the NMR spectrum and the nuclear spin-lattice relaxation rate, we determined that the antiferromagnetic transition in the donor layers occurs at 25 K. The structure of the NMR spectra in the antiferromagnetic phase resembles that of lambda-(BEDSe-TTF)2GaCl4. We used the angle dependence of the NMR shift in the paramagnetic phase and the experimentally determined demagnetization factor to estimate J pi d of lambda-(BEDSe-TTF)2FeCl4 as 3.4(7) T/mu B . This result shows that the pi-d interaction of lambda-(BEDSe-TTF)2FeCl4 is weaker than that of lambda-(BETS)2FeCl4. The different signs of J pi d between lambda-(BEDSe-TTF)2FeCl4 and lambda-(BETS)2FeCl4 could be attributed to the different paths for the pi-d interaction in the two systems
Finding and Analyzing Performance Pitfalls of On-Demand Paging of InfiniBand : InfiniBandのオンデマンドページングの性能問題の発見と分析
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