3164 research outputs found
Sort by
EXAMINATION OF THERMAL CONDUCTIVITY ESTIMATION MODEL OF CNT DISPERSED WATER
Get PDFProceedings of the 2021 International Workshop on Modern Science and Technology; September 29, 2021conference pape
MICROWAVE REMOTE SENSING OF FIRST YEAR ICE WITH SNOW COVER
Get PDFProceedings of the 2021 International Workshop on Modern Science and Technology; September 29, 2021conference pape
A REVIEW OF SINGLE IMAGE SUPERRESOLUTION RECONSTRUCTION BASED ON DEEP LEARNING
Get PDFProceedings of the 2021 International Workshop on Modern Science and Technology; September 29, 2021conference pape
室内模型実験を用いた 構造物の凍着凍上挙動に関する基礎的研究
Get PDFIn this study, laboratory model experiments were adopted as a research method to clarify
the behaviors of the frost heaving phenomenon in structures. The experiments were conducted
by placing structures in the soil with varying factors such as cross-sectional shape, burial depth,
overburden load, friction and density, and their freezing and thawing behaviors were observed.
It was confirmed that the inverted T-shape was effective in preventing the lifting of structures
due to frost heaving. It was also found that there was a high possibility of greatly reducing
the lifting of the structure by the frost heaving if an appropriate length of overhang could be
provided at a depth below the maximum freezing depth. These results suggest that, in the case
of a strip footing foundation with an inverted T-shape, burying the top of the footing at a depth
below the maximum freezing depth is an appropriate means of preventing the frost heaving
phenomenon.journal articl
多結晶α-Tiにおけるすべり系活動度のひずみ速度依存性の数値解析
Get PDFUniaxial tensile deformation of single-crystalline and polycrystalline α-Ti models was numerically simulated with strain rates ranging from 10-4 to 10-1 [/s] using a crystal plasticity finite element method, and we investigated the relationship between the activities of the basal and prismatic slip systems and the critical resolved shear stresses (CRSSs) depending on the strain rates. The simulation of single-crystalline model showed that CRSS of prismatic slip system was easier to increase than that of basal slip system although CRSS of both slip systems increased with strain rates. The nature of strain rate dependency affected the deformation mechanism of polycrystalline model: the simulation of polycrystalline model showed that the activity of basal slip system increased locally with strain rates, instead of reducing that of prismatic slip system. However, the local activation of basal slip system was inhibited when 1st pyramidal slip system was activated. These results indicate that the local activation of basal slip system can occur by strain redistribution between preferred regions for basal and prismatic slips with strain rates while activation of another slip system can inhibit that of the basal slip system.journal articl
Effect of specific surface area on the purity of methane hydrate formed from snow and ice powder
Get PDFガスハイドレートは高いガス包蔵性を有することから，ガス貯蔵媒体としての活用が期待されている．その際，純度の高いガスハイドレートを簡便な方法で生成することが求められる．本研究では，積雪の利用を念頭に置き，氷とガスとの接触のみでメタンハイドレートを生成し，その純度を測定した．材料には自然積雪および粉末氷を使用した．材料となる氷の比表面積がメタンハイドレートの純度に及ぼす影響を調べた結果，氷の球相当粒径が約 260 ミクロン以下の新雪を用いることで，純度が約 8 割を超える高純度なメタンハイドレートが生成可能であることがわかったjournal articl
A Case Study on Teaching Methods Applied to the Course “Topics on Japan” at Kitami Institute of Technology
Get PDFThere has been a wide range of discussions regarding the course of “Topics on Japan” taught at Kitami Institute of Technology (KIT) such as on its importance as learning subject and applied teaching methods, adopting a trial and error approach in education trying to adapt to changing times.
Although KIT provides courses to acquire basic academic knowledge, there were no courses offered to learn about Japanese society itself, which is why the course “Topics on Japan” was newly established in April 2014.
A survey we conducted with our students has shown that although the number of participants enrolling in the course increased significantly, we also encountered a variety of problems. For example, it was found that there was a discrepancy between the degree of interest in the subject and the degree of satisfaction after class. The results show that at this stage, several years after the introduction of the course, it is necessary to review the course again and consider a teaching method that enhances the learning effect.
At the same time, for the further development of this course, it is essential to consider the role and position of the university within its local environment, its contribution to the region, tourism and regional revitalization.departmental bulletin pape
硫酸化アルキルオリゴ糖鎖および糖鎖デンドリマーの抗HIVメカニズムの解明
Get PDF北見工業大学博士（工学）This thesis deals with the elucidation of anti-HIV mechanism in regard to the cluster effect of sulfated oligosaccharides and the role of long-chain alkyl group in sulfated alkyl oligosaccharides with potent anti-HIV activity. Oligosaccharide is a key word through this thesis. Since Schuerch reported for the first time in 1966 ring-opening polymerization of an anhydro glucose monomer, benzylated 1, 6-anhydro α-D-glucopyranan into a stereoregular polysaccharide after debenzylation to recover hydroxyl groups, (1→6)-α-D-glucopyranan (synthetic dextran) bearing stereoregularity, many synthetic polysaccharides are reported. Because synthetic polysaccharides have well-defined structures by distinct from naturally occurring polysaccharides bearing complex structures, it is convenient to know the relationship between the structure of polysaccharides and biological activities. The biological activities of sulfated polysaccharides such as blood anticoagulant and anti-HIV activities are dependent on their molecular weights, in general, the higher molecular weights give the higher biological activities. Sulfated polysaccharides exhibited the potent antiviral activities such as HIV, influenza, and dengue viruses and the biological mechanism was elucidated attributed to the electrostatic interaction between negatively-charged sulfated groups in sulfated polysaccharides and positively-charged amino acids in the viral surface glycoproteins.
There are still two undissolved problems on biological activities of sulfated poly- and oligosaccharides such as antiviral mechanism of sulfated polysaccharides and role of long-chain alkyl group on the antiviral activity. The answer of the first problem should be an electrostatic interaction and elucidated by SPR measurements between oligopeptides and sulfated polysaccharides. The second problem is assumed by the interaction with lipid bilayer of viruses. However, antiviral mechanism of oligosaccharides doesn't completely dissolved, especially, cluster effect and cytotoxicity. Therefore, the author wants to dissolve the two unclear problems of sulfated oligosaccharides.
The thesis consists in four chapters. The first chapter is instruction. The second chapter is on the elucidation of anti-HIV mechanism of sulfated cellobiose–polylysine dendrimers. The third chapter is on the relationship between anti-HIV activity and cytotoxicity of sulfated alkyl oligosaccharides. The last chapter is conclusions. In the second chapter, the author investigate the elucidation of anti-HIV mechanism of sulfated glycodendrimers by using newly synthesized sulfated cellobiose–polylysine dendrimers 1st, 2nd, and 3rd generations. Sulfated oligosaccharide-bearing dendrimers also had potent anti-HIV activity although sulfated oligosaccharide alone had low anti-HIV activity. It was found that the EC50 (50% effective concentration of sulfated polysaccharides on prevention of virus infection) values were 3.7, 0.6, and 1.5 μg/mL, respectively. The second-generation dendrimer was the most active, suggesting that the moderate distance between the terminal sulfated cellobiose units in the second generation dendrimer favored the high anti-HIV activity owing to the most effective electrostatic interactions developed due to the cluster effect of the sulfated cellobiose unit revealed by the SPR measurements. These biological results suggest that the distance between sulfated sugar units plays an important role in the anti-HIV. In the third chapter, the author exactly investigated the anti-HIV activity and cytotoxic mechanism of sulfated alkyl oligosaccharides. Anti-HIV mechanism of sulfated alkyl oligosaccharides was recently reported by our lab that the long-chain alkyl group was penetrated into the lipid bilayer of HIV and then sulfated maltoheptaoside portion was electrostatically interacted with HIV gp120 to inhibit the infection of HIV in vitro. However, it was reported previously that the cytotoxicity increased with increasing the length of the long-chain alkyl groups. The cytotoxic mechanism of sulfated alkyl oligosaccharides is still unclear. therefore, several sulfated alkyl maltoheptaosides were newly synthesized by using click reaction and the interaction with liposome as a model of HIV gp120 was investigated, indicating that the longer chain alkyl group gave higher association- (ka) and lower dissociation-rate (kd) constants by SPR measurements. These results suggest that the longer chain alkyl group in sulfated alkyl maltoheptaosides was strongly penetrated into the lipid bilayer of cells and the cytotoxicity was expressed.
In this thesis, high anti-HIV and cytotoxic mechanisms of sulfated cellobiose polylysine dendrimers and sulfated alkyl oligosaccharides were evaluated. The results lead to a more extensive investigation into the adaptability to the development of safety biomaterials.硫酸化糖鎖、アルキルオリゴ糖鎖は硫酸基による(-)電荷とウイルス表皮タンパク質の（＋）電荷との静電的相互作用によって抗HIV性を発現する。しかし、抗ウイルス性メカニズムについては完全には解明されていない。本論文では、未解明なクラスター効果および長鎖アルキル鎖の影帯について研究を行った。
これまでに当研究室では硫酸化糖鎖の抗HIV性メカニズム解明の研究において、硫酸基のクラスター効果の影響が大きいことを発表した。硫酸化オリゴ糖鎖自身の抗HIV性は低いが、デンドリマー構造にすることでクラスター効果が発現し、世代数が大きいほど抗HIV性も高くなると考えた。硫酸化オリゴ糖鎖デンドリマー第3世代を合成しカードラン硫酸の抗HIV性と比較した。しかし、抗HIV性はEC50=3.2-6.7μg/mLとなりカードラン硫酸のEC50=0.1μg/mLと比較して低くなった。この理由を解明すべく、第一世代から第三世代の硫酸化糖鎖デンドリマーを新規合成し、抗HIV性およびSPRでリポソームとの相互作用を調べた。第二世代デンドリマーはカードラン硫酸と詞程度の高い抗HIV性を示し、SPRでは最も高い結合速度定数、低い解離速度定数を持つことが分かった。この結果、硫酸化オリゴ糖鎖の間隔が相手タンパク質との相互作用が強くなり、その結果抗HIV性が高くなることを明らかにした。
また、硫酸化アルキルオリゴ糖鎖は分子量が低いにも関わらず高い抗HIV性を示すが細胞毒性も高くなる。これは長鎖アルキル鎖とオリゴ糖鎖との疎水性-親水性バランスが悪いためと推定された。そこで、C6～C18のアルキル鎖を持つ硫酸化マルトヘプタオシドをClick反応により合成し、抗HIV性、細胞毒性、SPRによるリポソームとの相互作用を定量的に調べた。その結果、アルキル鎖長がC12以上になると細胞毒性も大きくなりそれ以下では小さくなることが明らかになった。抗HIV性は大きな変化は見られなかった。これはアルキル鎖長が長いほど細胞の脂質二重膜との相互作用が強くなるため、抗HIV性も高いが細胞毒性も高くなると考えた。従って疎水性と親水性のバランスが抗HIV性および細胞毒性には重要であることが明らかになった。
以上、本論文では表皮タンパク質を持つウイルスとしてHIVを使用し、硫酸化糖鎖、オリゴ糖鎖のこれまで不明であった抗HIV性メカニズムを解明した。doctoral thesi