全國中小學科展

化學

Investigating the application of nanotechnology for detecting fishes hatching time

Introduction: Using advanced technologies such as nanotechnology in the food and fishery industry, as one of the most important industrial sectors of countries, has received too much attention. Traditionally, fishing and hunting have been considered important sources of supplying food. The subject and methodology: The study aims to investigate nanotechnology for detecting fish hatching time. This is a review article that collects the information from databases such as Sid, civilica, and Google Scholar. In the end, 22 papers were studied for extracting and collecting the required information from the abovementioned scientific database. Finding: After examining the food, drug, and agricultural-related papers published from 2009 to 2020, it was concluded that small Nano-sensors, controlling & monitoring systems made from nanotechnology can be installed on fishing nets, fishing rods, and other fishing equipment. These devices (Nano-sensors and controlling & monitoring systems) will help fishes so that they don’t get caught. In this way, as a fish gets close to the fishing equipment, it will receive sound, smell, or heat-based alarm. Therefore, the fish will stay away from the fishing equipment. The result: according to the finding of this study, it can be concluded that excessive fishing in the hatching time will be avoided by the application of nanotechnology in the fishing equipment. As a result, the following advantages will be secured: 1- There are lots of opportunists who misuse fish during the hatching time. With the application of nanotechnology, they will be stopped. 2- Opportunists are ambushing in different time points to misuse fish. Also, the guards might be ignorant. With the application of nanotechnology, guards are no longer required. 3- This plant is cost-effective too.

Laying waste to Energy problems

This research aims at exploiting civil and pre-treated industrial wastewaters that go into the purifier and those that come out of it after various treatments in order to build a galvanic cell with the goal of producing clean electric energy. Our background hypothesis is that it is possible to exploit the existing potential difference between these two types of water to generate electricity. In fact, the water sent for purification contains elements (carbon, nitrogen, sulphur, phosphorus, etc.) in a predominantly "reduced" state and its oxygen level is scarce. On the other hand, the water coming out of the process contains the same elements in a mostly "oxidized" state and it is rich in oxygen. Those chemical discrepancies should get the job done. In order to simulate the two types of water, two different solutions were prepared. The first one is highly concentrated with pollutants and gaseous nitrogen is insufflated in it to reproduce its anoxic environment. The second one’s pollution level is based on the Italian legislative limits of chemical contaminants for superficial waters (Legislative Decree 152/2006) and the semi-cell is insufflated with gaseous oxygen.

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。

五苯荑衍生物的多重螢光響應行為

本研究探討兩種五苯荑氟鏈取代衍生物(簡稱F5及F9)的刺激響應之特性及應用。F5及F9化合物粉末受到外力研磨以及蒸氣薰致時會產生力致螢光變色(Mechanochromism)及薰致螢光變色(Vapochromism)反應,我們選擇使用F5,利用放光光譜及PXRD對這兩種反應的機制進行探討。 再者,我們利用揮發法把F5及F9粉末製成晶體,以螢光顯微鏡照射340–390nm的紫外光,觀察F5及F9晶體的光致機械螢光變色(Photomechanofluorochromism)及F9晶體的光機械運動(Photomechanical effect),並利用放光光譜對其機制進行研究。 另外,我們將F5粉末長時間照射紫外光製備光二聚體(Photodimer),接著透過加熱使光二聚體熱回復回單體。再利用NMR測得各加熱時間下光二聚體與單體的比例,並由此推算出光二聚體熱回復性的反應速率常數。 此外,我們將F5混摻PEDOT:PSS,用drop-casting製成薄膜,觀察螢光變化,並討論其機制。 最後,我們結合力致螢光變色、薰致螢光變色和光致機械螢光變色,應用於多彩螢光繪圖。

以分子動力學模擬探討有機分子影響胰島類澱粉蛋白(IAPP)的聚集行為

近年來的研究指出:第二型糖尿病病徵與胰島類澱粉蛋白(islet amyloid polypeptide,簡稱IAPP)之聚集有關。如欲探討IAPP聚集機制以治療病症,需經多樣、多元的實驗條件進行試驗,這無疑是件耗時、耗費資源的大工程!本研究是以電腦軟體進行理論計算分析,採用分子動力學模擬系統,探討不同種類或官能基的有機分子對於IAPP作用之影響,再進一步觀察分子動態、統計系統能量,歸納出分子間的交互作用,釐清可能影響實驗結果的重要變因,期能達到提昇實驗設計、減少耗材浪費的綠色化學願景。本研究結果發現:在純水或稀薄食鹽水中,IAPP構形皆傾向摺疊結構;且具較高極性基團或易產生立障效應的有機分子會拉伸IAPP結構,使其分子間相互靠近聚集,形成β-sheet纖維;具較低極性基團的有機分子,易進入IAPP turn內,破壞引發聚集現象的疏水核心,進而抑制IAPP分子的積聚。

從天然物抓取微量抗癌藥物的工具之研究

本研究嘗試設計並合成出一具有特定結構之分子工具,期望利用化學反應的方式,以化合物結構的性質,與分子工具進行特定的反應,達到精準將目標具特定結構之少量化合物從巨量物質中分離的效果。 以苯環為基本結構,我們在反應中逐步加上我們所要的分子基團,以達成分子工具預期中的功能。在每一步的反應進行分離和純化之後,以NMR來觀察產物的結構與純度。以四步反應成功合成目標的分子工具後,我們以不同的方式測試其在葉片萃取液中大量化合物下的效果,證實分子工具能跟其中的特定成分產生反應,並被氟相溶劑分離出來,具有我們想要的部分功能。 在進行其他更進一步的測試之後,其可能可以成為一種新的方法,用於分離天然物中的一些目標化合物。

The effects of Different Synthesis Methods and Catalysts on Crude Aspirin

Aspirin is one of the most used and well-known medicines world-wide. It can be synthesized by reacting acetic anhydride and salicylic acid in a warm temperature of around 60-80°C. This reaction is usually catalyzed by sulfuric or phosphoric acid. This paper will investigate alternative catalysts, safer and more environmentally friendly, as well as compare different synthesis methods with different heat mediums, one using a water bath and the other amicrowave. By doing so, the effects of the catalyst and the method of synthesis on the yield, purity and environmental consequence of crude aspirin synthesis will be deduced. The targeted utcome is to find the alternative method as more energy efficient, and to find a greener safer catalyst to sulfuric and phosphoric acid. Further background information, exploration, and explanation is in the appendix. The targeted outcome will be to find a viable alternative catalyst that is safer and more environmentally friendly, and to find that the microwave synthesis method consumes less energy.

Synthesis of Substituted Pyrrolidin-2-ones and Isoindolines from Donor-Acceptor Cyclopropanes and Anilines/Benzylamines

The development of rapid and efficient synthetic approaches to the bioactive cyclic and polycyclic azaheterocycles is one of the most important challenges in organic synthesis. In this work effective and simple synthetic approaches to polysubstituted pyrrolidin-2-ones 2 and isoindolines 3 from donor-acceptor cyclopropanes 1, bearing the ester group as the one of acceptor substituents, and amines were developed. The γ- pyrrolidone based skeletons and isoindoline ring system is a constituent of many biologically active molecules, both natural and synthetic, and a key component of clinically relevant entities (Fig.1,2) [1,2]. The synthesis of pyrrolidin-2-ones 2 includes Lewis acid-catalyzed opening of the donor-acceptor cyclopropane with primary amines (anilines, benzylamines, etc.) to γ-amino esters, followed by in situ lactamization and dealkoxycarbonylation. The reaction has a broad scope of applicability; a variety of substituted anilines, benzylamines, and other primary amines as well as a wide diversity of donor-acceptor cyclopropanes bearing (hetero)aromatic or alkenyl donor groups and various acceptor substituents, can be involved in this transformation. In this process, donor-acceptor cyclopropanes react as 1,4-C,C-dielectrophiles, and amines as 1,1- dinucleophiles. The resulting di- and trisubstituted pyrrolidin-2-ones can be also used in subsequent chemistry to obtain various nitrogen-containing polycyclic compounds of interest to medicinal chemistry and pharmacology, such as benz[g]indolizidine derivatives. The synthesis of the substituted isoindolines 3 is based on the domino-reaction between donor-acceptor cyclopropanes, bearing in ortho-position of aromatic substituent a bromomethyl group, and different primary amines (e.g., anilines, benzylamines, cycloalkylamines) was developed. The reaction involves the generation of secondary amine followed by nucleophilic ring opening of cyclopropane with amino group. Moreover, this process provided a new practical method for the rapid synthesis of benzo[b]pyrrolizidinone 4 from readily available starting materials.

In Silico Modeling of Lovastatin Analogues as Inhibitors of HIV-1 Nef Protein

Currently, no method can completely eliminate the human immunodeficiency virus (HIV) in an infected person. HIV employs an accessory protein called Nef that forms a complex with cellular AP-1, preventing detection of HIV-infected cells. Lovastatin has been recently identified to inhibit the formation of said Nef-AP-1 complex, but its effective concentration is remarked to be far higher than other Nef inhibitors. This study aims to develop a modified lovastatin molecule exhibiting higher binding affinity to the HIV-1 Nef protein than lovastatin in silico. Modified lovastatin molecules based on the interaction map of lovastatin with Nef were modeled, and flexible ligand-flexible receptor docking to the Nef binding site was performed using AutoDock Vina. Residues within the Nef binding site identified by Liu et al. (2019) to be crucial (Glu-63, Val-66, Phe-68, Asp-108, Leu-112, Tyr-115) were set as flexible. Fragment-based drug design was utilized to append molecular fragments to lovastatin in order to maximize its interactions with said crucial residues. From the fragment-based approach, molecule F4 ((1S,3S)‐8‐{2‐[(2R,4R)‐4‐chloro‐6‐oxooxan‐2‐yl]ethyl}‐3‐(hydroxymethyl)‐7‐methyl‐1,2,3,4‐tetrahydronaphthalen‐1‐yl 4‐aminobenzoate) exhibited a binding affinity of -9.0 kcal/mole, and its estimated IC50 ranges between 0.25-0.51 μM which is at least 7.5 times lower than the reported IC50 of lovastatin from literature. This study presents insights on the key modifications to improve lovastatin as an HIV-1 Nef inhibitor and pertinent information about the Nef binding site for future drug development studies.

Ferrofluid──流體與磁場之研究

鐵磁流體是一種新型的功能材料,同時具有液體的流動性和固體磁性材料的磁性,由微奈米磁性顆粒、界面活性劑以及載液混合形成的膠體液體。本報告探討製備鐵磁流體的方式及過程,比較各種不同鐵磁流體製備方法的優缺點。並在化學共沉法中改變滴入氨水的稀釋 pH 值與其速率,建立一套標準稀釋氨水 pH 值量表,並探討其對產率的影響。 外加磁場也為操縱鐵磁流體的重要因素之一,本研究使用低成本自製磁力測量裝置測量不同磁鐵及不同角度、位置的磁力大小,並用其測量數值繪製多張圖表進行分析。從對磁場研究的過程也發現鐵磁流體在受磁鐵吸引時會產生類似泰勒錐之錐體,架設自製觀測設備,觀察多種變因對錐體行為之影響,同時對錐體進行數據分析。此點乃為本研究提出創新科學設計。