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。
Modification of silica surface with supercritical water as a tool indicating new possibilities of existing separation methods
Silica capillaries have been an integral part of the instrumentation used in many areas of analytical chemistry for decades, especially in analytical separations. In most cases, they are used without treatment, occasionally forceless chemical surface treatments are made to suppress or enhance the activity of silanol groups. The aim of this work was to disrupt the inner surface of the capillary, perfectly smooth from manufactory, so that relatively coarse and various structures would be created, and to study their influence on the separation efficiency. The uniqueness of the used solution is based on the use of special properties of water exposed to high temperatures and pressures (supercritical water), which is able to disrupt this chemically inert material because of its aggressivity. In total, over 2000 experiments were carried out in order to define conditions suitable for the formation of various types of surface structures. Due to the high amount of resulting data, our own database application was created, allowing not only to save the picture of the structure and experimental conditions information, but also to clearly sort them out and create image reports according to the specified parameters. Samples representing individual types of structures were then selected from this database and a number of silica capillaries with a configuration suitable for electromigration analyzes were prepared. The creation of a structured surface in the input part of the separation capillary enabled the separation of some classes of substances and biosamples, which cannot be analyzed on standard capillaries with a smooth surface. An example is the complete separation of two strains of Staphyllococcus aureus bacteria (MRSA and MSSA), or the use of the absorbing capabilities of a structured surface to study the interactions of these bacteria with bacteriophages. This ability was also used in the determination of Aspergillus fungus in a sample taken directly from the patient's lungs, where there was achieved a significant increase in the sensitivity of the analysis. Structured capillaries can also be used in the analysis of food samples, i.e., for the separation of β-lactoglobulins A and B in cow's milk, which belong to its main allergens.
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.