全國中小學科展

2015年

螂吞虎嚥-探討嗅覺及味覺刺激對蜚蠊口器、唾腺及砂囊的影響

本研究以不同濃度各種溶液作為嗅覺與味覺刺激,探討人體與蜚蠊的辨識率與口器反應,發現蜚蠊口器的嗅覺受器極為敏感,大致呈現劑量效應(dose response)趨勢,且可偵測人體無法辨識之揮發性極低的物質,且具熱量之營養物質可增強口器的反射行為。此外,利用記錄組織電位變化的方式,我們發現餵食蔗糖溶液時,蜚蠊唾腺放電反應減弱,推測蔗糖會抑制唾腺分泌水樣唾液,避免稀釋酵素濃度影響消化分解;餵食麩胺酸及醋酸溶液時,唾腺放電反應增強,推測其會引發唾腺分泌水樣唾液,稀釋過高濃度的溶液。而餵食蔗糖溶液時,蜚蠊砂囊放電反應減弱,推測蔗糖會抑制砂囊肌肉收縮;餵食麩胺酸溶液時,蜚蠊砂囊放電則增加,推測麩胺酸會增加砂囊肌肉收縮,以利磨碎食物。

Hay Aliens

The purpose of my project was to prove if the seeds of invasive plants are spread throughout the Peace region in hay harvested by local farmers. Invasive plants are so dangerous because they adapt to their environment fast and some of them can cause harm to both animals and humans. Within a year they can completely wipe the ecosystem out of native plants. Many invasive plants are either poisonous or can affect the systems of the animals body’s. I collected 22 hay samples from local farms around the North Peace region. I conducted a survey to help collect information about the samples. A pretest was conducted to determine which of two homemade sifters (one with three layers of decreasing size wire mesh, and one with 6 layers of materials with larger size holes) was the best for sifting through hay. I was able to determine that the larger sifter was easier for sifting hay. I sifted through all 22 samples with the larger sifter. I individually looked through each layer and removed what I believed to be seeds. Each seed was individually bagged, labeled, and photographed through a microscope. After each seed was photographed they were planted to help identify the seeds. I contacted a seed specialist. I was able to send him the images of my seeds. He helped me to identify my findings. I removed a total of 5568 potential seeds in my 22 samples. Out of all the potential seeds found 628 seeds were invasive. All invasive plants identified either cause pain to animals or they easily over take the native plants.

基於人眼感知範圍減少螢幕藍光強度之研究

我們每天的生活都離不開手機、電腦、電視等產品,因此藍光對眼睛造成的影響是所有人都會遇到的問題。本計劃希望能利用人眼對於不同顏色的敏感度,在人眼感知範圍內減少螢幕的藍光強度,以降低電子產品對眼睛帶來的負擔及傷害,同時維持螢幕畫面的正常顯色。市面上現有的方法除了成本較高,也都會使螢幕畫面變得昏暗; 若為了維持顯色的自然,則成效便會受到限制。本專題根據人眼對於色度的最小可覺差,參考基於麥克亞當橢圓的顏色差異計算方式,分別算出不同色彩空間上看起來相同的顏色關係表,並將螢幕上的顏色換為色差無法察覺且藍色強度較低的顏色,最後以手持式光譜儀量測螢幕輸 出的藍光強度驗證成效。與現行市面上的抗藍光方法相比,除了成本大幅降低以外,也能維持顯示器的正常顯色。未來希望能推廣至所有 LED 螢幕電子產品,並為色盲色弱患者設計不同色度感知能力的最佳調整方式。

Antiviral Therapy for Hepatitis C Virus (HCV): Black Mustard Seeds

Hepatitis C Virus (HCV) is an RNA virus, which is considered the main cause of progressive chronic liver disease, cirrhosis, and hepatocellular carcinoma (HCC) worldwide. The number of the patients who are infected with this sleeping virus is increasing rapidly every year, as the unsuitability of the current therapy – interferon α and ribavirin – for most of the genotypes is the main cause of these high rates. Hence, the recent researches are focusing on finding out a new immunotherapy to affect this virus. In this research work, Black Mustard (Brassica nigra) has been used as powdered spice samples to prepare aqueous extracts; One of the included phytochemicals in the black mustard; glucosinolates and their hydrolysis products, was proposed to be used for the HCV patients to prevent the virus progression. Also, the Isothiocyanates are shown with chemotherapeutic and anti-tumor properties. Moreover, some of the structure-related isothiocyanates have the ability to induce the enzyme paraoxonase-1 (PON-1) that is considered hepato-protective agent against liver impairment, inflammation, fibrosis and liver disease mediated by monocyte chemoattractant protein-1 (MCP-1), and is thought to affect the entry of the virus into the hepatocytes. The effect of the black mustard and the produced myrosinase enzyme on the HCV RNA replication is still unknown. In conclusion, the black mustard is thought to affect the progression and the fluidity of the HCV envelope resulting in impairment of viral binding and fusion.

地震與纜車的邂逅 Monitoring the Seismic Reduction and Vibration Resistance of Cable Car

本研究主要探討地震造成的纜車晃動,藉由自製的地震模擬器與纜車系統,探討各因素對纜車晃動之影響,設計纜車系統和車廂的減震裝置。研究結果顯示:一、地震時纜車斷電停駛位置愈靠近塔柱、相同長度纜繩上車廂個數較多、纜車重量較重、纜車臂較短,纜車晃動時間相對較短。二、所設計之減震裝置中,利用夾層中鋼珠轉動,使地震時只有外層纜車晃動而內層纜車輕微滑動的「雙層纜車」效果最佳。纜車系統塔柱則可參照建築物設置隔震元件,以減緩纜車晃動。本研究結果可望為未來應用之參考。

VERMICOMPOSTING-EFFICIENT DAIRY SLUDGE MANAGEMENT

The continued growth of dairy farming in NZ and the move toward keeping cows on stand-off pads has seen a major increase in two significant waste streams, the wood fibre that is scrapped off the surface of the standing pads and the effluent that is now concentrated at the site of these pads. In combination these waste streams offer the farmer an opportunity to recycle valuable nutrients back into the soil as an up-valued soil conditioner. This investigation explores vermicomposting as a tool to efficiently manage these two significant waste streams. Sludge was removed from a settling pond and mixed with a range of carbon products that are recommended by Dairy NZ for use in stand-off pads: wood chips, post peeling, sawdust and also wood shavings (used in calf sheds). The wood fibre/sludge mixtures were assessed on their acceptability to tiger worms (Eisenia fetida) by measuring the pH of the mixture and seeing if they corresponded with the preferred pH for tiger worms. The vertical spatial distribution of tiger worms was measured over a period of 15 days and the rate at which the worms moved into the different mixtures was assessed. The worm mass before and after this 15 day period was also measured to ascertain the mixtures’ ability to support worm growth. Finally, different ratios of sludge and post peelings removed from a calf shed were used in a choice chamber experiment to establish the worms’ preference. Tiger worms were used throughout the investigation as they represent the worm species most widely used in vermicomposting in New Zealand. Tiger worms feed on decomposing organic matter, bacteria and fungi in the upper organic horizon of soil. All of the unused wood fibre and dairy sludge tested lay within the acceptable pH range for tiger worms. Wood fibre exposed to large amounts of urine ie calf shed post peelings, that lie outside the acceptable range can be favourably adjusted with the addition of dairy sludge. All the particle sizes of the wood fibre tested were found to be acceptable to tiger worms and capable of supporting increase in their body mass beyond that of the compost. Due to the observation that the worms did not integrate themselves as fully in sawdust as the other fibres tested it is recommended that further investigation should be carried out before sawdust is used for vermicomposting. While a comparison of the average worm density in each mixture may indicate a preference for post peelings this cannot be statistically proven and more trials are recommended. The preferred ratio within the limits that were tested is 1:3 calf shed post peelings to sludge (41% dry weight). Vermicomposting can therefore be recommended as a possible onsite technology to process the twin waste streams of wood fibre and effluent generated by dairy farms. The next step would be to implement medium scale field trials with a continuous windrow system, testing resulting compost for its nutrient content and then comparing this output to that of current practises

Difluoromethylation of arylidene Meldrum's acid derivatives

Fluorine-containing compounds gained significant attention during the past decade1. About 20% of novel pharmaceuticals and 40% of novel agrochemicals every year contain at least one fluorine atom in the molecule. For a long time the most frequently used was trifluoromethyl group, but nowadays the most promising is the chemistry of partially-fluorinated groups. For example, the difluoromethyl substituent (CHF2) exhibits unique pharmacoforic properties capable of serving as lipophilic hydrogen bond donor thus being bioisosteric to hydroxyl group2. There are several general approaches for the formation of a required fluorinated fragment, one of them is direct nucleophilic fluoroalkylation. This approach is well-developed for trifluoromethylation reactions, such as addition of CF3-anion equivalents to C=O, C=N and electron-deficient C=C bonds or metal-catalyzed substitution in haloarenes3. However the similar difluoromethylation processes are still quite challenging. Herein we present a novel and convenient protocol for the synthesis of β-CF2H functionalized carbonyl compounds and carbinols by nucleophilic difluoromethylation of electron-deficient olefines. The process is based on a 1,4-addition of in situ generated4 phosphorus ylide Ph3P=CF2 2 to the arylidene Meldrum's acid conjugates 1. The resulting phosphobetaines 3 are hydrolized/protodephosphorilated without isolation, giving β-CF2H substituted carboxylic acids 4. The latter may be easily transformed to the corresponding ethers 5 and alcohols 6 without preliminary purification.

H.E.L.P. Heart Empowers Lifelong Pacemaker

EXPERIMENT 1---The effect of NaCl and Glucose Concentration on the efficiency of the cell I. Introduction Experiment on different concentrations of standard glucose solution (ranged from 0.125 M to 1.000 M) and standard sodium chloride solution (ranged from 0.250 M to 4.000 M) were done. We investigated the full concentration effect, which included both concentration of glucose solution and sodium chloride solution on the fuel cell’s output voltage, current and power. II. Procedures 1. Add 25.0 cm3 of Glucose solution of the tested concentration to the beaker representing the anode, and add 25.0 cm3 of distilled water to the beaker representing the cathode. 2. Add 50.0 cm3 of 0.250 M NaCl (aq) to both beakers representatively. 3. Fold a piece of filter paper and soak in fully into NaCl (aq) at cathode. 4. Clean and place the silver wires into the beakers representatively, and connect the air pump to the cathode. 5. Connect the cell to two multi-meters, each acting as a voltmeter and an ammeter respectively 6. Take the readings of multi-meters after 30 seconds. 7. Repeat steps 1 to 6 twice for the second and third reading of the cell. 8. Take average value among three values as the final reading of the cell. 9. Repeat steps 1 to 8 by replacing the NaCl (aq) with concentrations of 0.000 M, 0.500 M, 1.000 M, 2.000 M and 4.000 M, and the standard glucose solution with concentrations of 0.000 M, 0.125 M, 0.250 M, 0.500 M, 0.750 M and 1.000 M. III. Result of Experiment 1 When glucose concentration is increased from 0.000 M to 0.250 M, the output power increases, it is found that power generated is maximized at glucose concentrations between 0.125 M and 0.250 M. However, with further increase in glucose concentration from 0.250 M to 1.000 M, the power generated decreases. This shows that high concentration of glucose inhibits the generation of electricity, while higher concentration of sodium chloride solution can increase the output. EXPERIMENT 2---The effect of temperature on the efficiency of the cell I. Introduction In this experiment, the second effect - temperature on the fuel cell’s output voltage, current and power was investigated. In order to get a significant result, the effect of temperature on these measures with fixed 0.250 M glucose solution and sodium chloride solution concentrations varied from 0.500 M to 4.000 M had been investigated. II. Procedures 1. Add 25.0 cm3 of Glucose solution of the tested concentration (0.25 M) to the beaker representing the anode, and add 25.0 cm3 of distilled water to the beaker representing the cathode. 2. Add 50.0 cm3 of 0.500 M NaCl (aq) to both beakers representatively. 3. Fold a piece of filter paper and soak in fully into NaCl (aq) at cathode. 4. Clean and place the silver wires into the beakers respectively, and connect the air pump to the cathode. 5. Connect the cell to two multi-meters, each acting as a voltmeter and an ammeter respectively 6. Take the readings of multi-meters after 30 seconds. 7. Repeat steps 1 to 6 twice for the second and third reading of the cell. 8. Take average value among three values as the final reading of the cell. 9. Repeat steps 1 to 8 by varying the temperature from 42℃ to 32℃. 10. Repeat steps 1 to 9 by replacing the NaCl solution of 0.000 M, 1.000 M, 2.000 M, and 4.000 M respectively. III. Result of Experiment 2 The results showed a consistent trend and relationship of the effect of temperature on the output current, voltage and power of the fuel cell for 4 different concentrations of sodium chloride solution with fixed 0.25 M glucose solution. Generally, the results showed that the output power increases with temperature. EXPERIMENT 3---The effect of dialysis tubing and Nafion 117 on the efficiency of the cell I. Introduction Semi-permeable membrane separating glucose and oxygen, ensure the glucose oxidation only occurs at the anode, and preventing glucose oxidation occurs at the cathode, responds to maximize power output. Experimental study on two kinds of membranes, dialysis membranes and Nafion 117 films were done, by studying their fuel cell output voltage, current and power effects. Previous experiments showed that the optimal output of the battery is at 0.250 M glucose solution, Therefore, experimental conditions for glucose concentration is fixed on 0.250 M and sodium chloride solution concentration varies from 0.500 to 4.000 M. II. Procedures The Effect of Dialysis Tubing on voltage and current of the fuel cell 1. Pour 50 cm3 1.000 M NaCl (aq) to each compartment of the beaker separated by dialysis tubing. 2. Pour 0.250 M Glucose Solution into the compartment representing anode. 3. Connect the cell to two multimeters, which act as a voltmeter and ammeter respectively 4. Take the reading of the multimeters after 30 seconds 5. Repeat steps 1 to 4 twice for the second and third reading of the cell. 6. Take average value among three values as the final reading of the cell. 7. Repeat steps 1 to 6 with NaCl (aq) with concentration of 0.000 M, 0.250 M, 0.500 M, 2.000 M and 4.000 M to obtain the remaining data. The Effect of Nafion 117 on voltage and current of the fuel cell 1. Add 50 cm3 1.000 M NaCl (aq) and 50 cm3 of 0.250 M of glucose solution to the beaker. 2. Add 1.000 M NaCl (aq) to the Nafion 117 membrane pouch, and silver plate was put inside to become the anode. 3. Connect the cell to two multimeters, which act as a voltmeter and ammeter respectively 4. Take the reading of the multimeters after 30 seconds 5. Repeat steps 1 to 4 twice for the second and third reading of the cell. 6. Take average value among three values as the final reading of the cell. 7. Repeat steps 1 to 6 with NaCl (aq) with concentration of 0.000 M, 0.250 M, 0.500 M, 2.000 M and 4.000 M to obtain the remaining data. III. Result of Experiment 3 The result had shown that when the solution does not contain glucose (i.e. Glucose concentration equals to 0.000 M), Nafion 117 Membrane Cells have similar power outputs compared to the dialysis tubing cells. However, in 0.250 M glucose solution, the output of Nafion 117 membrane cell is about 1 to 5 times more compared to that of dialysis tubing cell. According to the experiment results, it was found out that the power output was maximized when the concentration of glucose solution and NaCl (aq) are 0.250 M and 4.000 M respectively. Under this concentration, the out of Nafion 117 membrane cell was 1336.68 nW which was 5 times higher than that of dialysis tubing cell. Hence, adopting Nafion 117 as the selectively membrane can greatly enhance the output of cell. It is believed that the special structure of Nafion 117 has limited the movement of glucose molecules, and prevented their oxidation at cathode. This has enhanced the oxidation of glucose at anode, and thus increased the power output of the cell.

口腔清潔-牙周致病菌(Porphyromonas gingivalis)對癌細胞生長之探討

牙周致病菌(Porphyromonas gingivalis)普遍分布於大部分人的口腔中,而牙周致病菌的熱休克蛋白GroEL在先前研究指出與牙周病和發炎有關;再者,研究證實了牙周病和癌症的相關,但尚未證實GroEL是否會增強腫瘤的增生。本研究藉此探討GroEL與腫瘤增生的相關性。結果顯示,小鼠被施打GroEL後,腫瘤體積明顯增加,死亡率也上升,並且血液中血管內皮前驅細胞的含量也增加,免疫組織染色法的結果也呈現出施打較高量之GroEL會使腫瘤內有較多血管的分佈;雞胚蛋的實驗中,更證實了GroEL會增加血管的生成。總結上述結果,推論P. gingivalis的GroEL會增加癌細胞的生長速度,而其機制可能來自於增加血管內皮前驅細胞的含量,刺激了血管的新生,提供了癌細胞生長的養分。所以口腔清潔,除了消除異味外,更可以預防癌症的發生。

星系演化? 剖析巡天資料庫驗證星系顏色與紅移關係

透過研讀論文Strateva et al. (2001;簡稱S01),開啟了我們對於星系的星等、星色考量紅移情況下之關係的興趣,並展開以下研究。S01利用Sloan Digital Sky Survey (SDSS)所提供的測光數據,首次依據顏色u*-r*,將星系解析為偏紅以及偏藍兩個族群。本研究藉由SDSS最新提供的光譜資料進一步取得精確紅移數據,經由 K-correction復原靜止坐標系中各星系的星色,並可透過距離模數消除距離對於星系亮度的影響。因此,本研究得以分辨出兩類星系族群的紅移演化。我們發現紅移效應和星系本質的特性對於 r*<17.77且z<0.3的星系有顯著的影響。在研究目標範圍內,兩類星系族群皆沒有發現紅移演化對於顏色的影響。本研究也與 S01作比較,討論了分析中可能的誤差來源。