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Proposal for the Restoration of Fire-Damaged Soil Using Water-Soluble Aromatic Compounds Derived from Soil Actinomycetes

The following issues associated with soil affected by wildfires were identified: First, there was a significant decline in the populations of anaerobic and aerobic soil bacteria, which play a critical role in the decomposition and cycling of organic matter. This decline resulted in reduced water retention capacity and porosity of the soil, leading to poor moisture retention and increased evaporation compared to unaffected soil. Moreover, the organic matter content in the soil was significantly depleted, inhibiting plant growth. Additionally, there was a notable proliferation of methane-producing bacteria, which contribute to the greenhouse effect. It was further observed that fire-damaged soils exhibit limited natural recovery, even over prolonged periods. .An investigation into the underlying causes of these problems revealed that actinomycetes, the primary microorganisms responsible for producing watersoluble aromatic compounds in soil, are particularly sensitive to heat compared to other bacterial species. Research demonstrated that the population and diversity of actinomycetes are significantly diminished in soils exposed to wildfires. To mitigate these issues, water-soluble aromatic compounds produced by actinomycetes were extracted and introduced into wildfire-affected soil. This intervention promoted the restoration of actinomycetes populations, enabling their normal growth in the affected soil. Consequently, various wildfire-induced soil problems were effectively resolved. These outcomes were confirmed through the study...Key Words: Actinomycetes, anaerobic and aerobic soil bacteria, methane-producing bacteria, wildfires, water-soluble aromatic compounds.

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滾動的「刺」界—濱刺麥滾動因素之探討

此實驗主要在探討不同條件對濱刺麥(Spinifex littoreus)滾動之影響,並利用模型(以下簡稱模擬球)來推導其實際滾動之效果。我們利用木板作為模擬球滾動的環境,並設計了四個操縱變因,分別為刺的長度、數量、材質(模擬球本身的條件)及風速(外在環境條件),測量模擬球的滾動軌跡、終端速度等物理量,並利用tracker、Excel等軟體分析數據,發現了刺的長度和環境風速與模擬球滾動的終端速度呈正相關;而刺的數量則與模擬球滾動的終端速度呈負相關,刺的材質主要影響滾動的阻力。

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芋頭生物塑膠材質的熱水即溶包研製

2023年聯合國氣候變遷大會(COP28)決議 2050年淘汰化石燃料。2022年聯合國環境大會制定從源頭減少塑膠垃圾的公約。為了回應這些全球目標,本研究利用廢棄芋頭皮的黏性製作生物塑膠,用於泡麵內調味料的熱水即溶包。常溫下為調味料包裝袋,熱水沖泡後即可溶解,成為富含營養的食材。 我們發現有八種配方能夠成功使其成形。其中,成本最低的配方為芋頭:明膠:小燭樹蠟:甘油:水=20:15:9:9:70。該產品在76°C以上的熱水中能夠溶解,第一次裂解時間為8秒鐘以內,之後會完全溶解。該裂解時間y(s)與溫度x(°C)的關係為:y=9.53×10¹¹x⁻⁵.⁹⁸。這使其適合用於泡麵時的熱水溫度,約 80°C以上。 物理性質包括:拉伸強度為0.70kgf/15mm,伸長率為20.4%,密度為1.11 g/cm³,含水率為20.3%。所有配方成分皆可食用,並可溶解於熱水中,適合作為泡麵調味料塑膠包的替代品,有助於減少農產廢棄物的處理量。

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理論設計與高效率合成三吲哚衍生物應用於癌症標靶藥物 Theoretical Design and Highly Efficient Synthesis of Triindole Derivatives for Targeted Cancer Therapeutics

抗癌藥物的研究一直受到重視,吲哚(indole)衍生物可助抵擋自由基,而二吲哚(Di-indole)衍生物已成為抗癌劑。鈣離子/鈣調蛋白依賴性蛋白激酶 (Ca2+/calmodulin-dependent protein kinase II,CaMKII)之抑制劑為癌症標靶藥物重要研究方向之一,抑制CaMKII可降低各種癌細胞增殖和存活,但目前尚無CaMKII抑制劑藥物。本研究以三吲哚為主架構,發展衍生物作為CaMKII抑制劑,期望可應用於抗癌劑。電腦軟體Discovery Studio2016模擬各種三吲哚衍生物分子模型與CaMKII α(PDB: 2VZ6)之結合能,選出結合能較大之化合物3,並延伸結構/活性(SAR)最佳化,進行一系列高效率藥物合成純化工作。經由送測生物細胞活性,其中先導化合物(lead compound) 3-1對癌細胞之毒性高且對CaMKIIα的抑制效果佳,符合癌症治療上的需求,將繼續最佳化此結構,並進行細胞訊號傳送途徑及動物實驗。

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非對稱反摺溝槽陣列過熱表面之液滴自推性能及冷卻效率

工業中時常會運用噴霧冷卻,以液滴的潛熱變化冷卻高溫表面。因此為了提升高溫噴霧冷卻的效率,本研究基於過往文獻與(Hsu, 2023)共同研究微奈米結構表面ARG上液滴的碰撞運動,並由實驗推論高溫表面蒸氣層和氣泡推力的作用。接著由單一液滴碰撞實驗推導實驗和理論受力模型並進行比較。最後進行單一液滴冷卻實驗並推論連續液滴冷卻實驗結果。本研究發現ARG表面的各運動特性均優於文獻,且利用液滴的受力更全面地了解液滴運動和冷卻效率的關係,更在最後驗證其冷卻效率優於對照組,並發想探討連續液滴冷卻的實驗方法,以更貼合工業上實際的噴霧冷卻。經過此研究,ARG表面能夠實際應用於工業上高溫表面的噴霧冷卻。

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Modal frequencies in a nonlinear beam-magnet coupled oscillator system

In this paper, I investigated the motion of a nonlinear coupled oscillator system consisting of two leaf springs secured to a non-magnetic base with magnets attached to the upper ends such they repel and are free to move. My results showed that the system exhibits the beats phenomenon, and interestingly that the frequencies show a dependence on initial conditions. I hence hypothesized this sensitivity is due to two sources of nonlinearities: geometric nonlinearity during large deflections of the leaf springs and the nonlinearity in the magnetic force. To test this hypothesis, a nonlinear mathematical model was developed, accounting for nonlinear beam effects up to third order and fully solving the nonlinear magnetic force using a current cylinder model, accounting for the tilting of the magnets. An approximate linear model was also developed for comparison. The theoretical models were validated experimentally by investigating the dynamic motion of the springs through time, as well as how the modal frequencies in the system depend on the initial displacement, the length of the spring, and the distance between the springs. The more accurate nonlinear model I derived shows good agreement with experimental results while the linear theory does not, highlighting the importance of nonlinearities in this system. An improved understanding of these nonlinear systems could lead to advancements in design and efficiency, and safety in various applications such as energy harvesting.

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Autonomous Ecosystem Surveillance Vehicle

As of 2021, there are 368 harmful algae blooms and over 6000 invasive species in the United States of America. Furthermore, it is reported that the United States spends more than 11.1 billion dollars per year on clean-up methods for marine debris. However, there currently isn’t a method to monitor aquatic problems simultaneously, autonomously, and efficiently, creating a capability in the aquatic biosecurity sector. To combat this, we have created an autonomous vehicle that can conduct long-term monitoring of freshwater bodies for up to 60 hours.

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Design and Simulation of a Honeycomb Sandwich Panel as a Heat-resistant and Durable Construction Material

One of the main factors that contribute to fire incidents and the excessive heat people feel during a heat wave is the building materials used, and one such material that possesses durable and heat-resistant properties is sandwich panels. A possible structure that can be used to model sandwich panels is honeycomb structures; however, further research has yet to be conducted on its applications as a heat-resistant urban construction material. This study aims to design a three-dimensional model of a honeycomb sandwich panel and simulate its performance under different thermal and structural stressors. A 3D model of the honeycomb sandwich panel was generated using Autodesk Fusion 360. Then, multiple versions of the panel were generated with varying heat-resistant core materials—namely, aluminum, nickel, nickel-copper alloy 400, and copper—along with polystyrene as the core material for the control model. The following properties of every panel were assessed using finite element analysis (FEA): static deformation, stress distribution, strain distribution, total heat flux, and thermal gradient. Results showed that when subjected to varying structural loads (2 kN, 5 kN, 7 kN), the nickel-core panel demonstrated the best results in terms of static deformation and strain distribution due to its relatively lower deformation and elongation values, respectively. Meanwhile, under the same structural loads, the aluminum-core panel performed better than other core materials in terms of stress distribution due to it having the relatively highest difference between its simulated von Mises stress and its yield strength. The honeycomb sandwich panels have also shown to possess heat-resistivity when subjected to a thermal load of 90°C, with polystyrene being the most promising material overall in terms of heat-resistance due to its relatively lower heat flux and thermal gradient. The results from this study would contribute to future research on honeycomb sandwich panels and may be used in real-life applications.

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Eradicating Cystic Fibrosis Biofilms by a Novel Non-Toxic, Multi-Pathway Salicylate Therapy

1.1. Cystic Fibrosis Biofilms Biofilms are bacterial aggregates in a matrix of polysaccharides, proteins and nucleic acids (Donlan, 2002). They account for 80% of all chronic infections and cause over 500,000 deaths annually. Cystic fibrosis (CF) is a genetic disorder characterized by mucus accumulation in the respiratory tracts (Morrison et al., 2020). This impairs mucociliary clearance, allowing chronic colonization by bacterial biofilms, leading to fatal respiratory failure, lung scarring, and necrosis of pulmonary epithelial tissues (Martin et al., 2021). 1.2. Obstacles in Current Treatments Three major therapies are used against CF biofilms: (1) aminoglycoside antibiotics like tobramycin, (2)non-aminoglycoside antibiotics such as ciprofloxacin and vancomycin, and (3) non-antibiotic therapies including flushing, chlorination, and ultraviolet disinfection. These have two major flaws. First, they are cytotoxic; 30% of patients experience acute kidney injury after three days of intravenous aminoglycoside therapy (Joyce et al., 2017). Furthermore, non-aminoglycoside therapies can cause phospholipid buildup in lysosomes of proximal tubule epithelial cells, accounting for 10-20% of acute renal failure cases. Second, antibiotic resistance due to horizontal gene transfer and mutations has significantly reduced treatment effectiveness. Therefore, cystic fibrosis biofilms remain a critical threat with few effective treatments. 1.3. Salicylate Derivatives This project tackled this issue using an innovative non-antibiotic approach with salicylate derivatives. Salicylates, a class of benzoic acids—benzene-based carboxylic acids (Figure 1)—used in painkillers and blood thinners, were investigated for their antibiofilm potential through a 3-step process: 1. Literature review: Identified three key biofilm therapeutic targets: quorum sensing, bacterial adhesion, and cell motility. Disrupting these pathways would result in biofilm eradication. 2. Molecule Identification: Recognized key molecules in each pathway: LasR, adhesins, and flagellin. Inhibiting these molecules would disrupt the pathways. 3. Screening: Found that salicylates could inhibit the identified molecules, though they had never been tested against cystic fibrosis biofilms.

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運用細胞水膠化技術製作微流道晶片進行抗原專一性T細胞之篩選 Flow-induced Mechanical Screening of Antigen Specific T cells with Biomimetic Microfluidic Chip

積極發展癌症相關治療策略極為重要,其中T細胞免疫療法(adaptive T cell therapy)是一深具臨床價值的選項。即是將T細胞自體內取出後並增殖到一定數量,而後將其回輸病人體內使得T細胞攻擊癌細胞。此方式關鍵的步驟在於必須要能夠篩選出足量的抗原專一性T細胞。現行主要的篩選方法雖然方便,但會誤捕不相關抗原專一性T細胞,降低治療效率。為解決此問題,本研究將利用水膠細胞技術,運用其完整保存生物膜的特性,模仿細胞膜之免疫突觸現象,搭配微流控晶片可控制流速改變沖刷力的特性,成功開發一可篩選親和力較高之T細胞微流道晶片。已在晶片內建立可置換任意抗原之水膠細胞單層,並以SIINFEKEL抗原作為模擬,達到極高之置換率。預期能在未來的研究中提升篩選專一性與數量,進而提升其臨床價值。

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碳源調控對酵母菌抵抗脫水能力及存活率影響

脫水技術在酵母菌應用方面則對保存和傳播重要的菌株十分有益。然而,脫水處理的酵母菌常常出現存活率過低的問題,若將生產規模擴大,導致的損失將不堪設想。 本研究探討脫水逆境下碳源調控對酵母菌抵抗脫水能力及存活率的影響。發現酵母菌面臨脫水生存逆境,會透過粒線體分裂與融合維持活性,此機制與DNM1密切相關。脫水前階段提供葡萄糖碳源可使酵母菌抵抗脫水逆境能力最佳,反之乙醇最差。甘油調節細胞內氧化還原平衡和滲透壓有助於細胞存活。脫水後復水階段提供葡萄糖可使酵母菌存活率最高,乙醇最差。脫水前碳源改變對存活率的影響更為顯著,而SNF1機制調控是影響酵母菌代謝養分及存活率的重要因素。 本實驗成果可提供酵母菌在食品工業、製藥、化工及生物燃料等領域的培養和保存技術,提高酵母菌的存活率和利用效率以減少浪費,具廣泛應用前景和經濟效益。

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Electrical Characterization of MoS2 Field-Effect Transistors at Cryogenic Temperatures

隨著矽基電晶體逐漸微縮,其元件效能將接近其物理極限,二硫化鉬 (MoS2) 等二維材料藉著其獨特的特性(如寬的能隙、高電流開關比及優異的載子遷移率等),可作爲矽的替代材料用於未來的電子科技應用。本研究旨在製造MoS₂ 的場效電晶體並研究元件之低溫特性。我們成功利用機械剝離法製備並轉移二維 MoS2薄膜至二氧化矽/矽基板上,並且製造MoS₂ 場效電晶體,並量測其室溫(300 K)至極低溫(~ 4 K)的電流特性,元件在此溫度範圍中具有優異的特性,能有效地調控電流調控,表現出良好的下閘極控制能力,同時具有低次臨界擺幅及高電流開關比(~ 106)。在極低的溫度(4 K)下,該電晶體仍能保持良好的運作,顯示出MoS₂應用於低功耗且高元件效能的低溫電子元件的潛力。

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