全國中小學科展

2022年

摻鈀鹵氧化鉍奈米晶體光催化還原二氧化碳

本研究將以BiOCl、BiOBr以及Pd/BiOCl的晶體製備二氧化碳還原之光觸媒,用以還原二氧化碳,期許能製造出具有經濟價值的還原產物,以緩解全球暖化並利用可再生能源。此外,我們藉由探討此類晶體在二氧化碳還原中的差異,比較加入不同鹵族元素及是否摻入鈀金屬對於光催化還原二氧化碳效率及產物的影響。 合成晶體後,我們透過X射線衍射儀(XRD)、掃描式電子顯微鏡(SEM)、能量散射X射線譜(EDX)進行晶體的鑑定,也確定Pd/BiOCl的晶體結構是以BiOCl為主體,且Pd鑲嵌在其表面。我們也以X光光電子能譜儀(XPS)了解晶體的鍵結型態及推測不同晶體表面的OVs相對含量,並以紫外光/可見光光譜儀(UV-vis)檢測樣品的能隙,推測其光催化性能。 我們發現摻入鈀的BiOCl晶體結構為分散的片狀結構,是三種晶體中唯一的奈米晶體,且能隙為三者中最小(2.46eV)、表面OVs含量也增加;表面附著的Pd奈米金屬顆粒更可以協助主催化劑的電子-電洞對維持分離狀態,促進其光催化效率。 最後我們將合成的BiOCl、BiOBr以及Pd/BiOCl晶體應用於光催化還原二氧化碳,並以氣相層析熱導偵測器(GC-TCD)及氣相層析質譜儀(GC-MS)檢測產物種類及產率,發現還原出的氣體產物有H2、CO、CH4。而總還原產物及含碳還原產物的產率皆以Pd/BiOCl為最高。

The Use of Brine Shrimp to Test for Water Pollutants

The use of brine shrimp nauplii to test for the overall toxicity of sediment samples is proposed. Brine shrimp nauplii were cultured with different concentrations of heavy metals, including chromium (III), copper (II), nickel, lead and zinc, and organic pollutants, including triclosan, oxybenzone, octinoxate and bisphenol A. The brine shrimp nauplii were observed under a dissection microscope to determine the death rate. Results showed that brine shrimp nauplii are more sensitive to copper, cadmium, bisphenol A and oxybenzone. The LC50 (24h) are 55.5, 24.9, 5.6 and 2.7 ppm respectively. Zinc is likely to have synergistic toxic effect with nickel or lead. The synergistic toxic effects of other heavy metals and organic pollutants should be confirmed with further investigations. Brine shrimp nauplii were treated with extracts from sediment samples collected from the oyster culture zone of the Deep Bay, namely Pak Nei, Sha Kiu Tsuen and Hang Hau Tsuen. The sediment samples were extracted with neutral sodium acetate to dissolve the exchangeable heavy metal ions and some organic pollutants. The death rate of brine shrimp nauplii treated with the sediment extract of Hang Hau Tsuen was similar to 1 ppm PBA. It was also about 10 to 20% higher than that of the other two sites (Pak Nei and Sha Kiu Tsuen). Since Hang Hau Tsuen is closer to the residential area and Lau Fau Shan Seafood Market than the other two sites, its sediment sample is likely to have a higher level of environmental pollutants. The results suggest that brine shrimp nauplii may be used as a biomarker to monitor the environmental changes in the overall level of pollutants in sediment samples.

A New Method For Microplastic Removal and Optical Measurement

Microplastics are tiny invisible plastic pieces that are piling up in the marine environment emerging as one of the many environmental issues which our planet is facing today. Researches for the removal of these particles are important because studies that have been made so far haven't come up with an effective solution. This project aimed to detect microplastics and remove them from aqueous environments with an effective and practical method then it was aimed to determine the removal amount of microplastics by optical measurements with the developed system. Firstly, the magnetic carbonanotubes (m-CNT) which is intended to hold onto the surfaces of microplastics was synthesized and added to the mixture of microplastics. Then the magnet within a glass tube was passed through the mixture and the sample was cleared of microplastics. A spectrometer was made to monitor this process and after its calibration, it was used to measure coffees with different concentrations. It has been shown that their concentrations can be determined by calculating the transmission values and Rayleigh scattering. In the end, it has shown that there are no micro or nano-sized plastic particles when removed with M-CNT, within the accountable range of the spectrometer that had been made. Hence the removal of the microplastics: an invisible threat for the environment has been studied by combining nanomaterials with unique surface properties in the removal process and an optical principle such as Rayleigh scattering, a new technique has been developed that can measure quickly, economically,

Anti-bacterial Crab bio-bandages with Bio-dressings 2.0

Commercially available bandages such as hydrocolloid are neither biodegradable nor anti-bacterial. Chitin is known to be the second most naturally available polysaccharide which could be transformed to chitosan which is known to be anti-bacterial (Hasan, 2018) (Chao, 2019) and haemostatic (Okamoto, 2003) (Hu, 2018). Chitosan can be further converted to hydrogel which is bio-degradable and has good water absorbance. Anti-bacterial crab bio-bandages and crab bio-dressings should be bio-degradable as it took 42 days and a month for complete bio-degradation respectively, so they should be better than commercial bandages such as Nexcare Hydrocolloid as the disposal of anti-bacterial crab bio-bandages with bio-dressings would no longer pose burden to landfilling or threat to our environment. Anti-bacterial crab bio-bandages with bio-dressings are anti-bacterial with degree of deacetylation of DD% (measured using FTIR Spectrum II) 82.6% (due to the presence of chitosan) even without the application of other anti-bacterial agents and hence can provide complete protection of wounds from skin and soft tissues infections and haemostatic (due to the presence of chitosan). After testing and certification based on IS997:2004 and BS EN 13726-1, they should meet many requirements specified. Anti-bacterial crab bio-bandages should be eligible for marketing. Some results were as follows: 1.4 Anti-bacterial effect of crab hydrogels and roasted crab hydrogels Pure chitosan, crab chitosan, crab hydrogels and roasted crab hydrogels showed significant anti-bacterial effect. NO oral bacterial colonies were present in drinking water with crab hydrogels. Thus crab hydrogels could serve as effective anti-bacterial wound dressings. 1.6 Basing on IS997:2004 standard, the load per unit of area of anti-bacterial bio-bandages was 342g/m2 which met the minimum requirement of 36g/m2, the anti-bacterial bio-bandages had stronger tension strength (>20N both in dry and wet conditions) than commercial hydrocolloid. (2.7N dry 2.8N wet) which was comparable with that required (50-67N) and pH of about 7 which met the pH range of 4.5-8. 1.7 The FSA Free-Swell Absorbency of synthetic blood of crab hydrogel bio-dressings was 1.86g per 5cm x 5cm dressing which was much higher than that of commercial hydrocolloid (0.299g per 5cm x 5cm dressing) based on BS EN 13726-1.

CONTACTLESS AND NON-DESTRUCTIVE DETECTION OF CHICKEN MEAT CONTAMINATION WITH LASER SPECKLE METHOD

Harmful microorganisms in food can cause deterioration of human health, poisoning and in some cases even death. Especially fresh meat and chicken products create a suitable environment for the growth of microorganisms in terms of the nutrients it contains, water activity and pH level. For this reason, detection of microorganisms in meat products is an important issue in terms of food safety and human health. In this project, it is aimed to detect live microorganisms in meat products, especially chicken meat, in a simple, non-destructive, non-contact and fast way using laser speckle method. Laser speckle images of healthy and stale chicken meat were taken, contrast parameter and correlation analysis of the obtained patterns were made. It was observed that the contrast parameter for staled chicken meat increased by approximately 3 times compared to fresh chicken. This increase provides an understanding of the difference between contaminated chicken and fresh chicken. Speckle density changes over time in relation to the movements of living microorganisms. Thus, the correlation in laser speckle density patterns taken from contaminated tissues is disrupted. In the measurements taken with photodiode, by analyzing the change of light intensity of the speckle patterns on fresh and contaminated tissues over time, the detection of microorganisms was made easier and more precisely without the need for image processing. The proposed measurement system is a new method that detects meat contamination with laser speckle imaging. It can be developed and made portable and can be used easily in homes. Since it is a simple, non-destructive and fast method, it can be used to determine the shelf life of meat in food distribution places and markets. In addition, it has the potential to be calibrated and used for other food products other than meat products. The system developed with this study is cheap and easy to use, and the laser speckle imaging method is used in a different field other than biomedical, contributing to the literature.

強菌來襲!口腔大騷動!——食品中乳酸菌對牙齒保健的影響

乳酸菌(Lactic acid bacteria)是生活中常接觸到的菌種,除了製作食品,也有研究指出部分乳酸菌菌株可抑止造成齲齒的「變異鏈球菌」生長,目前已有牙膏等產品號稱添加乳酸菌。但乳酸菌發酵產生的乳酸,會分解牙齒的琺瑯質,所以我們從發酵乳食品中分離出9株乳酸菌,並進行氫氧基磷灰石的分解實驗與對變異鏈球菌的抑菌實驗。經過實驗,1號、5號、6號與8號乳酸菌株對氫氧基磷灰石的分解能力較弱,而6號、8號與15號對變異鏈球菌的抑制效果較明顯,實驗結果交互比較後,得出6號和8號菌作為牙齒保健的應用價值較高。未來若能進一步研究,可嘗試以離心將乳酸菌各部位分離,研究其真正有抑菌作用的物質,並加以純化,應用於保健食品中。

BIOINFORMATIC PREDICTION OF CORONAVIRUS (SARS-COV-2) MUTATIONS THAT INCREASE CONTAGIOUSNESS

Inhibitory effects of the secondary metabolite of actinomycete were examined on cell cycle of the yeasts of S. pombe and S. cerevisiae. The secondary metabolite was obtained from cultivation of the actinomycete isolated from the soil of Owakudani in Hakone, Japan. The fifth fraction of the secondary metabolite by ODS column separation (HK-T5), which was soluble to pure methanol, was used in the present experiments. The HK-T5 brought about the delay of forming colonies of S. pombe for about 11 days compared to that cultivated without the HK-T5. The delay of the colony formation was longer for the S. pombe cultivated with more amount of the HK-T5. The cultivation with HK-T5 also brought about the extension of the lifespan of the S. pombe for more than 10 weeks in a liquidus medium. The cell life recovered the ordinary manner by removal of the HK-T5, meaning that the activities of the HK-T5 is reversible. These facts confirm the suppression of cell cycle, and the delay of cell growth by the HK-T5. These phenomena were similarly observed for S. cerevisiae. Comparison of the action of HK-T5 with hydroxyurea, which is an anticancer drug inhibiting the cell cycle at S phase, clarified that the inhibitory action of HK-T5 worked at the phase earlier than S phase. The combined effects of HK-T5 on the cell cycle were evaluated with triamcinolone acetonide (TA), or aspirin, the former of which is a drug synchronizing cancer cells in S phase, and the latter keeping human cells in G1/G0 phases. The combined use of HK-T5 with TA synchronized the cells at the phase slightly proceeding from G1 to S phase without toxicity. On the other hand, the combined use with aspirin made the inhibitory effect of HK-T5 inactive. Hence, the HK-T5 is attractive as a drug for the extension of cell lifespan, and anticancer therapy.

Automated Debugging System – Implementing Program Spectrum Analysis and Information Retrieval on Fault Localization

在程式專案開發中,偵測錯誤常為最耗時的環節,進而影響整個專案的開發時長。而現今雖有些許輔助開發者提升偵錯效能的工具,但這些工具也只能藉由提供編譯執行中的資訊讓開發者省去偵錯時的繁瑣步驟,仍須開發者自行評估每段程式碼的正確性。此研究透過程式段落分析與資訊檢索實現自動錯誤定位,在每個程式段落標記其成為臭蟲(bug)的可能性。在程式段落分析中,執行使用者之原始碼,並透過歸納最終結果為正確及錯誤之執行路徑差異分析出每個程式段落的可疑性。接著運用資訊檢索技術於資料庫中找尋相似之原始碼,並參考其偵錯結果優化現有之可疑性,形成最終之可疑性排名。此研究不只結合了上述兩種技術,更優化可疑程度之計算方法以及資訊檢索中的相似度比對機制,達到更完善的錯誤定位。(此指「臭蟲」非語法錯誤(Syntax Errors),而為邏輯錯誤(Logic Errors)。)

癌症治療新利器-奈米氧化鐵藥物磁性複合微粒之應用

溫熱化學治療(Hyperthermic Intraperitoneal Chemotherapy, 簡稱HIPEC),為將化療藥物加熱後灌注到腹腔內殺死癌細胞,但溫熱化學治療只能在開刀時使用,治療次數有限。為達到多次的熱化療效果,本研究開發奈米氧化鐵藥物磁性複合微粒(Nano iron oxide magnetic drug complex particles, NIOMP),可利用開刀時包覆複合微粒於腹腔,術後用磁場加熱,加上微粒化療藥物釋放,達到多次溫熱化學治療。NIOMP以鐵氧化物奈米粒子為核心,海藻酸鈉為外殼體,利用電紡法將前其與氯化鈣交聯產生凝聚性微粒。數據顯示最佳製作條件為16 kv高電壓、距離4 cm、噴速5μm/s,可得直徑大小約為200~450 μm穩定性高微粒。藥物釋放實驗顯示,NIOMP於2~7小時藥物釋放速率較穩定。利用可變磁場之電磁效應加熱NIOMP中氧化鐵磁顆粒,可於30分鐘內快速升溫至43℃。細胞相容性測試結果得知,NIOMP對細胞無毒性。本研究改善HIPEC的治療限制,可多次針對腫瘤患部局部熱化學治療,未來將可改善病人存活率。

Cross-lingual Information Retrieval

In this project, we evaluate the effectiveness of Random Shuffling in the Cross Lingual Information Retrieval (CLIR) process. We extended the monolingual Word2Vec model to a multilingual one via the random shuffling process. We then evaluate the cross-lingual word embeddings (CLE) in terms of retrieving parallel sentences, whereby the query sentence is in a source language and the parallel sentence is in some targeted language. Our experiments on three language pairs showed that models trained on a randomly shuffled dataset outperforms randomly initialized word embeddings substantially despite its simplicity. We also explored Smart Shuffling, a more sophisticated CLIR technique which makes use of word alignment and bilingual dictionaries to guide the shuffling process, making preliminary comparisons between the two. Due to the complexity of the implementation and unavailability of open source codes, we defer experimental comparisons to future work.