高鹽飲食對果蠅學習與記憶能力的影響及其細胞與分子機制
先前論文指出高鹽飲食會造成果蠅睡眠間斷(Jiayu Xie et al., 2019)、減短果蠅壽命(Deng-Tai Wen et al., 2020)。而另一篇論文則以小鼠作為實驗對象,發現高鹽飲食會影響小鼠記憶和學習能力(Giuseppe Faraco et al., 2018)。根據上述,高鹽飲食在不同生物中可能影響神經系統的功能,但果蠅學習與記憶能力的影響還未被探討。因此,筆者以果蠅作為模式生物,研究高鹽飲食對其學習與記憶功能是否障礙及實驗其可能的細胞與分子機制。在將野生型果蠅進行測試後,選擇了Canton-S做後續實驗,並發現餵食Canton-S 四天的高鹽食物後學習及短期記憶表現下降,而進行實驗確認是由高鹽飲食導致此障礙,再研究了一系列相關研究。 本次實驗中,首次以餵食高鹽食物對果蠅學習與記憶障礙方面進行研究,並了解到高鹽飲食也會讓果蠅產生學習與短期記憶能力障礙。目前為了找出真正的細胞與分子機制提出可使用的方法,在實驗其他可能的機制。
利用硫醇分子合成金奈米團簇應用於檢測自來水及游泳池水中次氯酸根
隨著大眾對於衛生要求的上升,許多抗菌及消毒成分被廣泛應用於水質處理中,其中次氯酸作為消毒殺菌劑大量使用於泳池及自來水的水質淨化中,然而現行標準方法測定水中有效氯所使用具危害的毒化物且步驟繁雜不利普及民生使用,發展簡便快速且靈敏的偵測方法勢在必行。本研究利用牛血清白蛋白(Bovine serum albumin, BSA)、不同的硫醇分子及金離子合成具螢光特性之硫醇修飾金奈米團簇 (Thiol ligand assists BSA capped gold nanoclusters, BSA/RSH-Au NCs),探討添加不同硫醇分子對所合成之金奈米團簇於不同pH值及常見離子對螢光強度之影響,並利用具有最佳螢光穩定性之2-巰基苯甲酸修飾金奈米團簇(Thiosalicylic acid assists BSA capped gold nanoclusters, BSA/TA-Au NCs),透析後進行次氯酸根檢測,其檢測線性範圍為0.98μM-1000μM,涵蓋法規規定游泳池水及自來水中次氯酸根之容許殘留濃度,最後此方法成功於游泳池水及自來水基質中檢測次氯酸根,分析樣品的回收率介於94.4%-95.6%。此外,在紙上添加金奈米團簇,並加入不同濃度的次氯酸根,觀察其螢光強度的變化,期望此方法未來應用於快篩試紙塗布材料快速檢測水質中次氯酸根濃度。
Development of an Audio Modulated Tesla Coil
Originally, the Tesla transformer was developed to transmit energy and messages wirelessly. But it did not prove itself for either of these applications, so today it is only used for research purposes. Over time, the Tesla transformer has evolved and improved. Today it is possible with Tesla transformers to generate powerful and highly precise controlled discharges. During operation, impressive high-voltage discharges occur at the transformer. A tesla transformer is basically a high voltage generator that achieves a voltage boost by using two magnetically coupled LC series resonant circuits of the same resonant frequency. The Dual Resonant Solid State Tesla Coil (DRSSTC) built in this work has a high power IGBT half bridge module to excite the primary resonant circuit at the resonant frequency. The IGBTs are driven in such a way that audible pressure waves, and therefore music, are generated by the electrical discharges at the high voltage electrode. Within the scope of this work were the following two questions: - How is a DRSSTC designed and built? The DRSSTC system realized in this work is about 80 cm high and reaches about one-meter-long discharges. The design, development, and construction of the transformer are documented in detail and extensively in this thesis. - How does one measure an electrical voltage of 200,000 V, which changes sign more than 100,000 times per second? Two approaches have been taken to measure the voltages. Derived from the energy balance of an ideal capacitor and an ideal coil, a secondary voltage of about 200 kV was calculated via secondary current measurement. The second approach uses a voltage measurement via an in-house developed measuring electrode and a calculated divider ratio between the measured voltage and the secondary voltage. A relatively unrealistic secondary voltage of about 750 kV was measured since the divider ratio depends on approximate values. Nevertheless, the measuring electrode can be used for investigations of the voltage curve, or the divider ratio can be calibrated via the secondary current measurement. The development of such a transformer laid the foundation for much further research and scientific analysis.
HOST TARGET PROTEINS OF SPIKE PROTEIN OF SARS-COV-2
Coronavirus Disease 2019 (COVID-19) is a newly emerged infectious disease caused by the new severe acute respiratory syndrome (SARS) coronavirus (SARS-CoV-2). In less than one year, the virus has spread around the entire world, killing millions of people and disrupting travel and business worldwide. During infection, the virus uses its Spike protein to dock onto the Ace2 protein on the surface of its human host cell. Spike is 1273 amino acids long and only a short fragment of Spike (319-541) is sufficient to bind Ace2. We hypothesized that the remaining protein sequences of Spike might have functions for viral replication beyond the binding of Ace2. We have performed Split-Ubiquitin protein-protein interaction screens to isolate human proteins by their ability to bind to Spike, and we have identified Annexin2A2 and Cytochrome b as novel human protein interaction partners of Spike. Annexin2A2 is involved in both endocytosis and exocytosis, and the protein interaction with Spike might help the virus to enter and exit its host cell. The presence of the mitochondrial Cytochrome b protein inside the cytosol promotes apoptosis, and the protein interaction with Spike could speed up sapoptosis of the infected human cell. The Nub cDNA libraries that we have generated also allowed us to screen for synthetic peptides that interact with Spike. We have isolated two synthetic peptides, FL1a and FL7a, derived from the non-coding parts of human mRNAs by their ability to interact with Spike. We found that both FL1a and FL7a interact with the C-terminal half of the Spike protein. We also found that FL7a is able to block the Spike-Spike self-interaction at the C-terminal half of the Spike protein and we think that this could block the reassembly of the Spike protein in the host cell during viral reassembly. We hope that those synthetic peptides could be used as drugs due to their ability to block protein-protein interactions of Spike with human host proteins that are essential for viral replication.