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Control of Barnacle Settlement by Poly (Lactic Acid)
No full text九州工業大学博士学位論文 学位記番号:生工博甲第200号 学位授与年月日:平成25年3月25日第一章 緒言||第二章 PLAおよびOLA からの乳酸溶出挙動||第三章 OLAフィルム上でのキプリス幼生の付着挙動||第四章 PLA/PEコンポジットからの乳酸溶出挙動とキプリス幼生の付着抑制||第五章 溶出LAの海洋生物に対する毒性影響評価||第六章 実証実験 －有明海海苔養殖場でのフジツボ付着抑制試験－||第七章 結言本実験はポリ乳酸(PLA)の加水分解特性を利用したフジツボ付着抑制効果を検証した。背景として、フジツボの付着は船底に付着する事により船舶の運航速度の低下や網などの養殖器材へ付着する事により引揚げ作業の労働負荷増大などによる水産業・養殖業への悪影響が現在起こっている。そのため付着生物を忌避する船底塗料が開発され、現在では環境負荷の少ない材料による付着抑制効果を検討する実験が全世界で盛んに行われている。環境負荷低減のため今回は生分解性プラスチックであるPLA を使用し加水分解により生じた乳酸によるフジツボ付着制御について検討した。本研究の論文は第1 章から第8 章までで構成されている。第1章では、緒言として、第1-1章序論、第1-2 章海洋生物の生活史と水産業への影響、第1-3 章防汚システムの研究開発、1-4章生分解性プラスチックの利用展開についてのこれまでの付着生物と防汚技術の進展及び生分解性プラスチック利用にあたって現在発表されている技術の問題点とPLLA の展望について示した。第2 章では、PLA 中の乳酸溶出挙動として淡水における実験ではなく、これまで行われていなかった海水中でのPLLA からの乳酸の溶出挙動を示し、pH に対して乳酸が影響を及ぼす事無く溶出する事を解明した。第3 章では、PLA フィルム上でのフジツボキプリス幼生の挙動について考察した。フジツボの付着期間であるキプリス幼生のPLA フィルム上での挙動を示す事により、PLA から溶出された乳酸がキプリス幼生に対して付着抑制効果と乳酸高濃度帯において死滅する事を明らかとし、分子量の減少による乳酸溶出量の増大によりキプリス幼生の付着率に変化を与える結果を得た。第4章では、PLA/PE フィルム上でのフジツボキプリス幼生の挙動について考察した。PLA 単体での使用した場合、乳酸濃度が近傍で高濃度に達するためフジツボなどの付着生物以外に影響を及ぼす可能性を考慮した実験となっている。PLA/PE フィルム上においても乳酸の溶出が確認され、溶出した乳酸がキプリス幼生の付着を抑制する事を解明し、PLA の含有量が低い場合は分子量より配合量に応じてキプリス幼生の付着に変動を与える結果となった。第5 章では、生物に対する乳酸の毒性評価について検討している。ハオコゼ(Hypodytes rubripinnis)とあさり(Ruditapes philippinarum)について乳酸の毒性試験を行い、海水中10ppm 濃度であればハオコゼ及びあさりに対して生活影響が出ない事を証明した。さらに、キプリス幼生の50%志望乳酸濃度LC50及び付着に対するEC50 を測定する事によりキプリス幼生に対して18ppm 濃度で50%乳酸付着濃度EC50 を発現し、LC50 との差が約12 倍である事よりキプリス幼生に対して乳酸は生存率に影響を与えず、付着に対して直接影響を及ぼしている事を示した。第6 章では、応用展開として有明海海苔養殖場での海洋浸漬実験について述べている。PLA の分子量及び含有量を変化させたサンプルを有明海に浸漬させ2010 年9 月9 日から2011 年9 月10 日までの約一年間の浸漬実験により乳酸含有サンプルはフジツボ付着抑制効果を海洋中においても発揮する事が明らかとなり、付着強度は乳酸を含まないサンプルに比べ乳酸含有サンプルは約1/2 倍の付着強度を発揮し、乳酸は付着抑制効果だけでなく付着強度を低下させる事が明らかとなった。第7 章では、緒言についてまとめた。これまでの結果より、PLA の加水分解により生じた乳酸は、その他海洋生物に生態影響を与えない段階でフジツボキプリス幼生の付着機構に作用しフジツボ付着抑制効果を発揮し、付着抑制効果は、キプリス幼生の死滅に関係して減少するのではなく海洋中での安全性を確保した新規材料になりえる事が示された
Impedancemetric Hydrocarbon Gas Sensor Using Perovskite-Type Oxide
No full text九州工業大学博士学位論文 学位記番号:工博甲第347号 学位授与年月日:平成25年3月25日第1章 序論||第2章 ペロブスカイト型酸化物のBサイト金属がセンサ特性に与える影響||第3章 ペロブスカイト型酸化物のAサイト金属がセンサ特性に与える影響||第4章 金属触媒の表面担持によるセンシング特性への増感効果||第5章 SmFeO3薄膜の形態制御||第6章 総
大腸菌のカタボライト制御の解析と、その変異株が複数の糖の同時消費に及ぼす影響
No full text九州工業大学博士学位論文 学位記番号:情工博甲第281号 学位授与年月日:平成25年9月27日1. Introduction||2. Materials and methods||3. The effect of the dilution rate on the catabolite regulation in the continuous culture of E. coli||4. The effects of several gene mutations on the catabolite regulation of E. coli||5. The effects of Δcra, crp+ and Δpgi on the co-consumption of multiple sugars||6. Concluding summary and future perspective
Electrochemical RNase A Detection Using an Electrode with Immobilized Ferrocenyl Deoxyribooligonucleotide Containing Cytidine Residue
Get PDFA ferrocenyl deoxyribooligonucleotide (FcODN(rC)) with contiguous cytosine bases and a single ribonucleotide, cytidine, was immobilized on a gold electrode, and this electrode was used to detect RNase A. RNase A activity in a solution was assessed using cyclic voltammetry, and it was found that the current response of the sensor electrode decreased with increasing enzyme concentration. An extremely low detection limit of 1.0×10−11 g mL−1 RNase A was observed, with 15–90 % changes in the current signal. RNase activity can be an indicator of a number of diseases; therefore, this probe has great potential for applications in medical diagnostics
Schottkey barrier measurement of nanocrystalline Lu3N@ C80/Au contac
Get PDFElectrical and structural properties of nanocrystalline solids of C80 fullerene encapsulated with a Lu3N cluster, Lu3N@C80, have been studied by measuring x-ray photoemission spectra, x-ray diffraction, and current-voltage characteristics of the Lu3N@C80/Au Schottky contact in the temperature range of 300 - 500 K. The nanocrystalline solid sample of Lu3N@C80 fullerene consists of grains characterized with an fcc structure and those grains become larger in size after pressing the powder sample at 1.25 GPa. The current-voltage characteristics measured at various temperatures showed that there are no significant dependences on both the Schottky barrier and the carrier mobility on electric field. The Schottky barrier of the Lu3N@C80/Au contact is determined to be 0.71 ± 0.04 eV
Latex Migration in Battery Slurries during Drying
Get PDFWe used real-time fluorescence microscopy to investigate the migration of latex particles in drying battery slurries. The time evolution of the fluorescence signals revealed that the migration of the latex particles was suppressed above the entanglement concentration of carboxymethyl cellulose (CMC), while it was significantly enhanced when CMC fully covered the surfaces of the graphite particles. In particular, a two-step migration was observed when the graphite particles flocculated by depletion attraction at high CMC/graphite mass ratios. The transient states of the nonadsorbing CMC and graphite particles in a medium were discussed, and the uses of this novel measurement technique to monitor the complex drying processes of films were demonstrated
An Image Registration Method for Head CTA and MRA Images Using Mutual Information on Volumes of Interest
Get PDFSCIS&ISIS 2014 : Joint 7th International Conference on Soft Computing and Intelligent Systems and 15th International Symposium on Advanced Intelligent, December 3-6, 2014, Kitakyushu, JapanImage registration is an important and a fundamental task in computer vision and image processing field. For example, to make a surgical plan for head operation, the surgeons should gain more detailed information from CT angiography (CTA) and MR angiography (MRA) images. And the abnormalities can be easily detected from the fusion image which is obtained from two different modalities. One of the multiple modal image registration methods is matching the CTA and MRA, by which the image of head vascular could be enhanced. In general, the procedure for fusion is completed manually. It is time-consuming and subjective. Particularly the anatomical knowledge is required as well. Therefore, the development of automatic registration methods is expected in medical fields. In this paper, we propose a method for high accurate registration, which concentrates the structure of head vascular. We use 2-D projection images and restrict volume of interests to improve the processing affection. In experiments, we performed our proposed method for registration on five sets of CTA and MRA images and a better result from our previous method is obtained
Development of a membrane-based microwave mediated electrochemical ELISA method for TNF-α detection in patients with periodontitis
No full textThe tumor necrosis factor-α (TNF-α) is implicated in periodontal disease, and there was an attempt to quantitate it by a membrane-based microwave-mediated electrochemical enzyme-linked immunosorbent assay (MMeELISA) using p-aminophenyl phosphate (pAPP) with an over-all time of 1.5 h. A differential pulse voltammetric signal increased linearly with an increase in the amount of TNF-α with a detection limit of 0.48 pg mL−1. This bio-sensing platform revealed a significant difference in the TNF-α level between GCF samples from periodontal patients and healthy volunteers
Organic-inorganic composites designed for biomedical applications
No full textSeveral varieties of ceramics, such as Bioglass-type glasses, sintered hydroxyapatite and glass-ceramic A–W, exhibit specific biological affinity, i.e., direct bonding to surrounding bone, when implanted in bony defects. These bone-bonding ceramics are called bioactive ceramics and are utilized as important bone substitutes in the medical field. However, there is a limitation to their clinical applications because of their inappropriate mechanical properties. Natural bone takes a kind of organic–inorganic composite, where apatite nanocrystals are precipitated on collagen fibers. Therefore, problems with the bioactive ceramics can be solved by material design based on the composites. In this paper, current research topics on the development of bioactive organic–inorganic composites inspired by actual bone microstructure have been reviewed in correlation with preparation methods and various properties. Several kinds of inorganic components have been found to exhibit bioactivity in the body environment. Combination of the inorganic components with various organic polymers enables the development of bioactive organic–inorganic composites. In addition, novel biomedical applications of the composites to drug delivery systems, scaffolds for tissue regeneration and injectable biomaterials are available by combining drugs or biological molecules with appropriate control of its microstructure
Apatite mineralization behavior on polyglutamic acid hydrogels in aqueous condition : effects of molecular weight
Get PDFApatite-polymer composites mimicking specific structure of natural bone are promised as bone substitutes with moderate flexibility able to be fabricated into desired shapes as well as bone-bonding bioactivity. In order to precipitate the apatite on polymer surfaces, aqueous processing using solution supersaturated to the apatite has been attracting as much attention. Polyglutamic acid (PGA) is a promised candidate of the polymer, since it has high apatite-forming ability owing to abundant carboxyl groups able to trigger the heterogeneous apatite nucleation. Although combination of PGA with different molecular weight is expected to provide design of organic-inorganic composites with moderate bioresorbability, precise relationship between the molecular weight of the PGA and its apatite-forming ability has been remained unclear. In the present study, PGA hydrogels with different molecular weight were prepared by covalent cross-linking using ethylenediamine. Difference in apatite formation in simulated body fluid (SBF) was interpreted in terms of their chemical structure. It was found that hydrogels prepared from PGA with higher molecular weight showed tendency to have higher apatite-forming ability. It was attributed to high content of the carboxyl group remaining on the hydrogel due to low degree of the cross-linking