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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
51

Associations of Lifestyle Factors (Smoking, Alcohol Consumption, Diet and Physical Activity) with Type 2 Diabetes Among American Adults from National Health and Nutrition Examination Survey (nhanes) 2005–2014

Liu, Ying, Wang, Kesheng, Maisonet, Mildred, Wang, Liang, Zheng, Shimin 17 October 2016 (has links)
Background: Over the long term, unhealthy lifestyles can lead to many health problems, especially type 2 diabetes (T2D). The aim of the present study was to determine associations between lifestyle factors (smoking, alcohol consumption, physical activity, and diet) and T2D in American adults (aged ≥20 years) in a nationally representative sample. Methods: Data for 12 987 American adults participating in the National Health and Nutrition Examination Survey 2005–2014 were evaluated. Weighted multiple logistic regression models were used to examine associations between the four lifestyle factors and T2D after adjusting for demographics and socioeconomic status (SES). Prevalence trends for T2D were examined using Cochran–Armitage tests. Results: There was a significant increasing prevalence trend for T2D among American adults. Smokers and individuals consuming >12 alcoholic drinks in the past year were less likely to report having T2D than non‐smokers (odds ratio [OR] 0.41; 95% confidence interval [CI] 0.35–0.48) and those consuming(OR 0.46; 95% CI 0.39–0.55). Participants with light physical activity have a greater likelihood of having T2D than those engaging in vigorous physical activity (OR 5.72; 95% CI 4.30–7.60). Individuals consuming a poor diet were more likely to report having T2D than those eating an excellent diet (OR 1.18; 95% CI 1.02–1.41). All these relationships remained significant after adjustment for demographics and SES. Conclusion: All four lifestyle factors were significantly associated with T2D among American adults. The findings of the present study provide useful information for healthcare providers that may help them promote specific lifestyle modifications.
52

カイコのインスリン様ペプチド(ボンビキシン)の生理的機能に関する研究

溝口, 明 03 1900 (has links)
科学研究費補助金 研究種目:一般研究(C) 課題番号:04640655 研究代表者:溝口 明 研究期間:1992-1994年度
53

Exploring Biopolymer-Clay Nanocomposite Materials by Molecular Modelling

Wang, Yan January 2015 (has links)
In this thesis, bio-nanocomposites made from two alternative biopolymers and montmorillonite (Mnt) clay have been investigated by molecular modelling. These biopolymers are xyloglucan (XG) and chitosan (CHS), both of which are abundant, renewable, and cost-effective. After being reinforced by Mnt clay nanoparticles, the polymer nanocomposites gains in multifunctionality and in the possibility to register unique combinations of properties, like mechanical, biodegradable, electrical, thermal and gas barrier properties. I apply molecular dynamics (MD) simulations to study the interfacial mechanisms of the adhesion of these biopolymers to the Mnt nanoplatelets at an atomic level. For the XG-Mnt system, a strong binding affinity of XG to a fully hydrated Mnt interface was demonstrated. It was concluded that the dominant driving force for the interfacing is the enthalpy, i.e. the potential energy of the XG-Mnt interacting system. The adsorbed XG favors a flat conformation with a galactose residue in its side chain that facilitates the adsorption of the polymer to the nanoclay.  The XG adsorption was found do depend strongly on the hydration ability of counterions. The binding affinity of XG to Mnt was found to be strongest in the K-Mnt/XG system, followed by, in decreasing order, Na-Mnt/XG, Li-Mnt/XG, and Ca-Mnt/XG. The competing mechanism between ions, water and the XG in the interlayer region was shown to play an important role. The dimensional stability upon moisture exposure, i.e. the ability of a material to resist swelling, is an important parameter for biopolymer-clay nanocomposites. While pure clay swells significantly even at low hydration levels, it is here shown that for the XG-Mnt system, at a hydration level below 50%, the inter-lamellar spacing is well preserved, suggesting a stable material performance. However, at higher hydration levels, the XG-Mnt composite was found to exhibit swelling at the same rate as the pure hydrated Mnt clay. For the CHS-Mnt system, the significant electrostatic interactions from the direct charge-charge attraction between the polymer and the Mnt clay play a key role in the composite formation. Varying the degree of acetylation (DA) and the degree of protonation (DPr) resulted in different effects on the polymer-clay interaction. For the heavily acetylated CHS (DA &gt; 50%, also known as chitin), the strong adhesion of the neutral chitin to the Mnt clay was attributed to strong correlation between the acetyl functional groups and the counterions which act as an electrostatic “glue”. Similarly, the poor adhesion of the fully deprotonated (DPr = 0%) neutral CHS to the clay is attributed to a weak correlation between the amino functional group and the counterions. The stress-strain behavior of the CHS-Mnt composite shows that the mechanical properties are highly affected by the volume fraction of the Mnt clay and the degree of exfoliation of the composite. The material structure has a close relationship to the material properties. Biopolymer-clay nanocomposites hold a bright future to replace petroleum-derived polymer plastics and will become widely used in common life. The theme of the thesis is that further critical improvements of these materials can be accomplished by development of the experimental methods in conjunction with increased understanding of the interactions between polymer, clay, water, ions, solutions in the polymer-clay mixtures provided by molecular modelling. / I denna avhandling har molekylär modellering och molekyldynamisk (MD) simulering använts för att studera modellsystem för bio-nanokompositer bestående av montmorillonit-lera samt två olika sorters biopolymerer – xyloglukan (XG) och kitosan (CHS). Båda dessa polymerer är naturligt förekommande och mycket vanliga. De är dessutom förnyelsebara och kostnadseffektiva. Då polymererna förstärkts med nanopartiklar av montmorillonit får det resulterande kompositmaterialet en unik kombination av egenskaper såsom mekaniska, elektriska, termiska och barriär egenskaper etc. Genom att använda molekyldynamiska (MD) simuleringar, studeras här växelverkan mellan dessa biopolymerer och lernanopartiklar (Mnt) på grundläggande atomistisk detaljnivå. Mellan XG och Mnt i ett fullt hydrerat system kunde stark bindningsaffinitet påvisas. Den dominerande drivkraften för affiniteten var entalpi, d.v.s. potentiell växelverkansenergi. Den adsorberade XG-kedjan antar en platt konformation på ytan. Ett förslag utifrån simuleringsresultaten var att galaktosresidyn i xyloglukanets sidokedja underlättar adsorptionen till lerytan. Simuleringarna kunde också visa att adsorption av XG till Mnt beror starkt på motjonernas hydreringsförmåga. Bindningsaffiniteten mellan XG och Mnt var som starkast i K-Mnt/XG- systemet. Därefter följde, i minskande ordning, Na-Mnt/XG, Li-Mnt/XG och Ca-Mnt/XG. Det kunde visas att strukturen vid gränsytan styrs av konkurrerande mekanismer mellan joner, vatten och XG. Dimensionsstabilitet vid fuktexponering, d.v.s. förmågan hos ett material att motverka svällning, är en viktig egenskap för biopolymer-lernanokompositer. Ren lera sväller signifikant även vid låga fukthalter. Dock kunde MD simuleringar visa att ett modellsystem av XG-Mnt behåller sitt ursprungliga interlamellära avstånd vid hydreringsnivåer under 50%, vilket indikerar ett stabilare material. Vid högre hydrering uppmättes dock svällningen vara densamma som för ren lera. I CHS-Mnt-systemet visade det sig att direkt elektrostatisk växelverkan med signifikant styrka mellan laddningar på polymer och Mnt-yta spelar störst roll för kompositformeringen. Olika effekt på polymer-lerväxelverkan uppnåddes genom att variera acetyleringsgraden (DA) respektive protoneringsgraden (DPr). För den tungt acetylerade CHS-polymeren (DA &gt; 50%, även kallad kitin) visade sig den starka vidhäftningen bero på korrelation mellan acetylgrupperna och motjonerna som i sin tur verkade som ett elektrostatiskt “lim”. På liknande sätt kunde den svaga vidhäftningen mellan fullt deprotonerad (DPr = 0%) neutral CHS och lera förklaras med en betydligt svagare korrelation mellan aminogrupperna och motjonerna. Spänning-töjningsbeteendet hos CHS-Mnt modellen visar att dess mekaniska egenskaper beror kraftigt på volymsandelen Mnt och graden av exfoliering i kompositen. Materialets struktur är nära relaterat till materialegenskaperna. Framtiden för nanokompositer av biopolymerer och lera är ljus då de kan komma att ersätta oljebaserade plaster och användas frekvent i våra dagliga liv. Materialen kommer successivt förbättras genom utveckling av experimentella metoder i kombination med molekylmodellering för ökad förståelse för växelverkan mellan polymer, lera, vatten, joner och lösningsmedel. / 本论文利用分子动力学模拟技术研究了两种备选生物大分子与蒙脱土(Montmorillonite, Mnt)(一种粘土)组成的生物纳米复合材料,分别是木葡聚糖(Xyloglucan, XG)/蒙脱土和壳聚糖(Chitosan, CHS)/蒙脱土。木葡聚糖与壳聚糖都是自然界广泛存在的生物大分子,资源丰富且取材面宽,提取及加工成本低廉,加之可以生物降解并可再生,是优秀的生物复合材料备选原料。经过蒙脱土纳米颗粒加固后,这些基于生物大分子的复合材料将获得多功能且有多种独特特性相结合的优点,比如,更好的力学性能,生物可降解,良好的导电性能,传热性能和屏蔽气体与液体侵扰的能力等等。论文中,我们采用分子动力学模拟的方法着重对生物大分子与蒙脱土在界面上的粘附相互作用机理进行了深入探讨。  首先,对于木葡聚糖/蒙脱土纳米复合材料,我们发现糖分子与土分子间有着很强的天然亲和力。研究证明它们之间的这种相互作用,热焓是主要的推动力,也就是糖和土分子间的相互作用势能。含有半乳糖残基的木葡聚糖分子(本文中亦称天然木葡聚糖分子)吸附到粘土表面后,分子构型呈现扁平状,半乳糖残基似有辅助木葡聚糖大分子吸附到粘土颗粒上的作用。  进一步研究发现,木葡聚糖分子在粘土表面上的吸附与溶液中抗衡离子的水和作用密切相关。在钾离子平衡的糖/粘土系统中,糖分子与土分子的相互作用最强,钠离子平衡的糖/粘土系统次之,紧接着是锂离子平衡的糖/粘土系统,最弱的是钙离子平衡的糖/粘土系统。研究发现,离子,水分子,以及糖分子在粘土层间的竞争机制在糖分子的粘附过程中起着重要的作用。  材料暴露于潮湿环境中的尺寸稳定性,也就是材料抗肿胀的能力是生物大分子/蒙脱土所构成的复合材料的重要参数。蒙脱土自身即使在很低的潮湿环境下就会有明显地膨胀现象,然而,对木葡聚糖/蒙脱土复合材料来说,尺寸稳定性可以在水和值低于50%以下有效保存。其夹层尺寸的稳定保持暗示了材料在这个程度的潮湿环境下的稳定性。然而,当水和值高于50%时,木葡聚糖/蒙脱土复合材料将出现明显的肿胀现象,表现在夹层尺寸的明显增大,且其膨胀速率与粘土自身的膨胀速率逐渐趋于相当水平。  其次,对于壳聚糖/蒙脱土复合材料,我们发现由电荷-电荷间直接产生地强烈的静电吸引作用是壳聚糖分子与蒙脱土分子相互粘附并构成复合材料的关键因素。通过改变壳聚糖分子的乙酰化程度(Degree of acetylation, DA)和质子化程度(Degree of protonation, DPr),糖分子与土分子的相互作用有着显著地不同。对于乙酰化程度(DA)高于50%的壳聚糖分子(亦成为甲壳素分子chitin, CHT),电中性的甲壳素分子与土分子间的强吸附作用源于乙酰基功能团与抗衡离子的强相关性。抗衡离子此时扮演着类似于“电子胶”的作用,可以有效地将电中性的甲壳素分子与土分子粘结在一起。类似地,当质子化程度最低时,亦即壳聚糖分子完全非质子化,即呈现电中性时,较差的糖/土吸附作用源于氨基功能团与抗衡离子的较弱的相关性。  进一步对壳聚糖/蒙脱土复合材料的分子系统进行应力应变计算发现,复合材料的力学性能直接受蒙脱土体积分数和其剥离程度的影响,通常,粘土的体积分数越大体系的力学性能越高,且剥离程度对材料的整体性能也有直接影响。因此,材料的结构与其性能的表征有着密切联系。  我们相信生物大分子与蒙脱土构成的生物复合材料有着光明的前景,可以取代石油提取物制成的塑料材料,并将能够广泛应用在日常生活中。通过实验技术的改善和应用分子模拟技术对复合材料体系中生物大分子,蒙脱土分子,水分子,离子,溶液环境等混合物质相互作用的理解增加,这种可再生的新材料将会得到重要改进,这也是整本论文的主旋律。 / <p>QC 20150520</p> / Bio-nanocomposites
54

台灣網路虛擬偶像之行銷策略研究

張家茹, Vanisa Chang Unknown Date (has links)
摘 要 本研究旨在探討台灣網路虛擬偶像發展較為成功的案例,由“均為崛起於網路動畫的台灣本土網路虛擬偶像;均藉由網友病毒式行銷、口碑行銷迅速走紅;均有影視、唱片界等豐富背景的經營創意團隊;均有朝網路虛擬至實體發展的跨媒體行銷計畫;均有台灣寬頻影音娛樂網站之內容提供者定位”共五大因素,挑選出三個代表個案—「阿貴(A-Kuei)」、「訐譙龍(G.G.Long)」、「牛奶糖家族(Miluku)」。研究方法上採取文獻分析以及包含深度訪談、網站內容分析的個案研究法,期望能藉由本初探性研究,予國內虛擬偶像行銷與動畫網站相關業者有所借鏡和全方位行銷策略之參考。 研究目的: 一、由文獻分析及市場現象觀察了解外來與國內虛擬偶像之行銷概況; 二、了解台灣網路虛擬偶像之行銷策略及執行; 三、綜合本研究調查分析結果,提出網路虛擬偶像之全方位行銷策略建議。 研究發現: 一、網路虛擬偶像成功之內外部因素; 二、虛擬偶像動畫網站經營之轉型; 三、網路虛擬偶像角色建構的轉型; 四、以功夫武俠片結合知名巨星朝全球動畫市場發展; 五、愛情成為亙古不變最保險與暢銷的行銷主題; 六、兩大類虛擬與實體結合的虛擬偶像推廣模式。 全方位行銷策略之建議: 一、以病毒行銷結合資料庫管理與網路虛擬社群經營; 二、運用口碑行銷並找出趨勢的引爆點與網路中樞; 三、以商品的植入式行銷結合連續劇商務。
55

預測第二型糖尿病患者之胰島素注射意圖:應用計畫行為理論並探討情緒之影響 / The prediction of insulin injection intention among patients with type 2 diabetes: an application of TPB and exploring the impact of emotions

張榮哲, Chang, Jung Che Unknown Date (has links)
胰島素自我注射是第二型糖尿病的重要治療方法。然而,許多病患的心因性胰島素抗拒(PIR)使他們拒絕胰島素治療,因而導致血糖控制不良。本研究目的即嘗試找出影響第二型糖尿病患者接受胰島素治療與否之可能因素。我們採用計畫行為理論(TPB)為基本架構,此理論主張「態度」、「主觀規範」、「覺知行為控制」三個變項可決定對某行為之意圖,而意圖可預測此行為之發生。此外,我們將情緒變項整合進TPB架構中以提昇預測力,包括「同時情緒」(對行為本身當下之心理或生理反應)與「預期情緒」(預期未來行為之後果成真時的情緒反應)。我們採自陳式問卷,橫斷研究設計,總計457位目前未使用胰島素之第二型糖尿病患者參與研究。階層迴歸分析結果,三個TPB變項(態度、主觀規範、覺知行為控制)均顯著預測胰島素治療之意圖,可解釋39.1%變異量;加入情緒變項後,整體模式解釋力提昇,可解釋43.2%意圖之變異量,「負向同時情緒」及「負向預期情緒」均為顯著預測因子。比較血糖控制較佳(HbA1C < 9%)與血糖控制較差(HbA1C ≧ 9%)兩組受試者,「負向同時情緒」是研究模型中唯一有顯著差異之變項。本研究結果顯示TPB可成功應用於解釋PIR,而情緒變項之影響亦不容小覷。 / Insulin injection is an important treatment in the care of type 2 diabetes mellitus. However, psychological insulin resistance (PIR) has long been an obstacle for many patients to achieve optimal glycemic control. The purpose of this research is to identify the influencing factors in decision-making process of type 2 diabetic patients whether or not to undergo insulin therapy. We adopted the theory of planned behavior (TPB) as our theoretical basis, which argues attitude, subjective norm and perceived behavior control (PBC) are determinants of behavioral intention, and intention is the precursor of behavior. Besides, we integrated extra emotion variables into TPB, which were anticipatory emotion (immediate psychological and physical responses toward the behavior itself) and anticipated emotion (affective responses expected to be experienced in the future when behavioral outcomes occur), to expanded the predictive power of research model. A cross-sectional questionnaire study design was employed, and a total of 457 currently not using insulin type 2 diabetic patients participated in this research. The hierarchical regression analysis revealed that all three TPB variables (attitude, subjective norm, PBC) significantly predict intention to use insulin, which account for 39.1% variance of intention. After the addition of emotional variables, the research model explains intention variance up to 43.2%, with negative anticipatory emotion and negative anticipated emotion being significant determinants. In the comparison of better glycemic-control (HbA1C < 9%) and worse glycemic-control (HbA1C ≧ 9%) participants, negative anticipatory emotion is the only variable in our research model significantly differs between both groups. The results of this research indicate not only TPB is a useful framework in realizing PIR, but also the impact of anticipatory and anticipated emotions cannot be overlooked.
56

半乳糖凝集素-3促進乙型類澱粉蛋白寡聚合作用 / Galectin-3 facilitates amyloid-beta oligomerization

鄭光閔, Zheng, Kuang Min Unknown Date (has links)
阿茲海默症是一種隨著年齡老化有關的神經退化性疾病,其特徵主要為記憶喪失及認知功能失調。阿茲海默症有兩個主要的病理指標,包含了因為濤蛋白造成的神經纖維糾結以及乙型類澱粉蛋白堆積而成的老化斑塊。乙型類澱粉蛋白是由類澱粉前驅蛋白經β-分泌酶及γ-分泌酶連續裁切生成大小約4-kDa的胜肽。乙型類澱粉蛋白會相互堆積形成寡聚體,並且高分子量寡聚體進一步再堆積成不可溶性的乙型類澱粉蛋白纖維及老化斑塊。半乳糖凝集素-3是半乳糖凝集素家族的一員,目前已知半乳糖凝集素-3調節各種細胞的功能,例如發炎、腫瘤生長以及細胞間的黏附,而在癌症中則有促使癌細胞積聚的能力,然而在大腦中的作用仍尚不清楚。在本研究中,我們使用APP/PS1基因轉殖小鼠作為阿茲海默症的動物模型,並且在其大腦中研究半乳糖凝集素-3對於乙型類澱粉蛋白堆積的作用與機制。結果顯示在野生型小鼠的海馬迴中過度表現半乳糖凝集素-3會促進乙型類澱粉蛋白的堆積,而將乙型類澱粉蛋白注射在半乳糖凝集素-3基因剔除小鼠的海馬迴,則會觀察到乙型類澱粉蛋白寡聚合作用的減少。乙型類澱粉蛋白的注射也會增加海馬迴中半乳糖凝集素-3的表現。在APP/PS1小鼠的海馬迴可以觀察到半乳糖凝集素-3的表現量會隨著年齡增長而增加,而具有抑制發炎及免疫反應的PIAS1在APP/PS1小鼠海馬迴中的表現量則會隨著年齡增長而減少。在探討半乳糖凝集素-3調節乙型類澱粉蛋白寡具體作用的過程中,我們發現半乳糖凝集素-3基因剔除小鼠的海馬迴中能夠代謝乙型類澱粉蛋白的腦啡肽酶表現量是野生型小鼠的兩倍多。研究結果顯示半乳糖凝集素-3對於乙型類澱粉蛋白的堆積扮演了重要的角色以及可能在阿茲海默症的病理機制中具有重要的作用。 / Alzheimer’s disease (AD) is an age-related neurodegenerative disorder which is characterized by progressive loss of memory and other cognitive functions. The two pathological hallmarks of AD are extracellular amyloid plaque and flame-shaped neurofibrillary tangles of the tau protein. Aβ is a 4-kDa protein that is resulted from sequential cleavage of the amyloid precursor protein by beta-secretase and gamma-secretase. Once Aβ is produced, it will aggregate to form oligomers and high molecular weight (HMW) oligomers will further assemble to form large insoluble fibrils and plaque. Galectin-3 (Gal-3) is a member of the β-galactoside-binding galectin protein family. Gal-3 is known to regulate various cellular functions, such as inflammation, tumor progression and cell-cell adhesion. In cancer cell, Gal-3 enhances homotypic aggregation, but its role in the brain is much less known. In the present study, we examined the role and mechanism of Gal-3 in Aβ aggregation in the brain by adopting the APP/PS1 mice as an animal model of AD. Results revealed that overexpression of Gal-3 enhanced Aβ oligomerization, whereas Aβ injection into hippocampus of Gal-3 KO mice reduced Aβ oligomerization. Aβ injection also increased Gal-3 expression in the hippocampus. Gal-3 expression is also increased in APP/PS1 mice and this effect is more significant along with ageing. Meanwhile, the expression of protein inhibitor of activated STAT1 (PIAS1) that suppresses inflammation and immune response was decreased with ageing in APP/PS1 mice. We further found that the expression level of neprilysin, an enzyme that degrades Aβ, was increased for approximately two-folds in Gal-3 KO mice compared with WT mice. These results suggest that Gal-3 plays an important role in Aβ aggregation and possibly in the pathology of AD.
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食品因子による生体防御を目的としたDNA傷害マ-カ-の開発と応用

大澤, 俊彦, 山下, かなへ, 三村, 精男, 中山, 勉, 豊國, 伸哉, 内田, 浩二 03 1900 (has links)
科学研究費補助金 研究種目:試験研究(B) 課題番号:05556021 研究代表者:大澤 俊彦 研究期間:1993-1995年度

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