全國中小學科展

2022年

探討豬籠草捕蟲籠的組織結構、發育吸收與物理結構Explore the Organizational Structure, Development, Absorption and Physical Structure of Pitchers of Nepenthes

紅瓶豬籠草的捕蟲構造是由膨大後的葉柄固定在莖上,再由葉柄下凸的維管束及扁平處的維管束內縮向前端延伸發育成籠蔓,緊接著籠蔓的前端再膨大並經由細胞凋亡特化出類圓筒型、封閉的「空心葉」,最後特化出無柄腺鑲嵌在內層細胞上負責分泌、消化、吸收。無柄腺旁的原生質絲直徑較一般植物大5-10倍,幫助吸收。由於籠蓋不能閉合,下雨天時籠內物質容易傾倒,豬籠草演化出「來者不拒」的捕食策略。除了紅色食用色素和無機物以外,不管是含氮物、水溶性、酯溶性小分子皆吸收,甚至連蔗糖及大分子的澱粉、蛋白質,都以耗能的胞吞作用吸收,這與捕蠅草只吸收小分子的含氮物質及酯溶性的物質不同。而懸吊捕蟲籠的籠蔓,可以比自身重35倍的超強支撐力,維持捕蟲籠開口向上不傾倒溢出,保持較高的自然盛載量,提升捕食競爭力。

Prismalla: Mist water collector

The lack of drinking water in human settlements triggers a series of problems that are linked and affect the development of humanity: health problems, lack of water security for companies, lack of jobs, insecurity, among others. We observe this problem in the communities of the municipality of Las Vigas de Ramírez, Veracruz, where there is a great problem with the water supply, although there is a high presence of mist. Faced with this situation, we undertook the task of investigating a water harvesting method that is easy to implement, operate and maintain. We investigated and analyzed the methods of mist condensation through physical barriers, finding that the polyethylene shadow mesh was the means to achieve this, because it allows the passage of the wind, it is very light, easy to manipulate and above all that it presents the phenomenon of percolation that allows water droplets of various diameters to be accommodated therein. We designed a device that allows to present a mist catchment area through a prismatic structure enabled with meshes and condensed water receivers, portable, easy to use and maintenance and very economical with a performance of 20 liters per day. To achieve our project, factors such as air humidity, dew point, wind speed and direction, height, temperatures and available spaces must be considered.

The influence of lanscape on nest preferences and behavior of twig nesting Hymenoptera

The occurrence and behavior of insects is significantly affected by the environment they live in. In this thesis, I dealt with the influence of structure of landscape on nesting preferences of Hymenoptera. For this comparison I had chosen to work with twig-nesting Hymenoptera, for which I have placed artificial nest opportunities into four biotopes – heath, edge of a heath, country lanes between fields and field. The studied location is located south of Znojmo near Podyjí national park. Particularly, I have focused on small carpenter bees of genus Ceratina. My results show that there is a big difference in the species distribution between the habitates of field and heath. The habitats of edge of a heath and country lanes make up a gradient between these two biotopes. The ecosystem of fields was preferred by a sphecid wasp Pemphredon lethifer and Ceratina cyanea. On the other hand, the ecosystem of heath was preferred by Ceratina chalybea, Ceratina nigrolabiata and megachille bee Hoplitis tridentata. I had also found out that in species that are more abundant on heaths, there is higher mortality of offsprings. Heaths were a place of the highest competition between species, as a result of which species with a lower body weight (Ceratina nigrolabiata) have been pushed into narrower twigs by larger species (Ceratina chalybea). I recorded a high number of nests in biparental bee Ceratina nigrolabiata, which were guarded only by mother in fields and country lane habitats. This may indicate that Ceratina nigrolabiata is only facultatively biparental, not strictly biparental as was considered until now.

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.

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.

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。

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.

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.

半正鑲嵌圖形中的捷徑問題

本研究從在方格棋盤中走捷徑的問題出發,推廣至由多個相異正多邊形所組成的半正鑲嵌圖形棋盤,其沿格線走捷徑的方法數與最短路徑。研究中,我們針對所有8種1律半正鑲嵌圖形進行分類探討,包括截半六邊形、截角六邊形、扭稜六邊形、小斜方截半六邊形、大斜方截半六邊形、扭稜正方形、異扭稜正方形、截角正方形圖形。我們將每種棋盤進行「轉正」,使它對應於唯一的矩形棋盤,達到「捷徑同構」,因而原本半正鑲嵌圖中的捷徑問題就等價於方格棋盤的捷徑問題。我們將走捷徑方法數的通解分類,發現有組合數類、以及階差與指數混合兩大類,並分析康威表示法與通解的關係。

PVA unveiled the actual role of starch in the Briggs-Rauscher reaction

The Briggs Rauscher reaction (BR reaction) is one of the famous oscillating reactions; the aqueous mixture of KIO3, H2SO4, H2O2, C3H4O4, MnSO4, and starch exhibit color change between yellow and blue-purple repeatedly. The blue-purple color formation is due to the iodine test reaction caused by inclusions of polyiodides such as I3- and I5- in the helical structure of starch. Therefore, starch has been regarded as only an indicator in the BR reaction. But our seniors have found that the oscillation did not last without starch. They hypothesized that starch’s linear helical framework is necessary to elongate the lifetime of the oscillating reaction. If this hypothesis is correct, similar BR-type oscillations must be observed when other polymers with helical structures are used instead of starch. We found the literature which reports that polyvinyl alcohol (PVA) forms a helical structure and indicates the iodine test reaction. In our research, we studied the BR reactions using PVA, with different saponification degrees and viscosities. First, we studied the correlation between the structural features of PVA and the iodine color reaction by spectroscopic approach, exhibiting that PVA with low saponification form helical structures and show the iodine color reactions, which gives red color solutions. Second, we found that additions of the helical-structured PVA to the reaction solution instead of starch induces the BR-type oscillating reactions, while PVA without helical structure induces only a few numbers of oscillations. This is the world-first example of the oscillating reaction using PVA. The oscillation that lasted for 6 minutes with 23 oscillations was almost the same as that of the general BR reaction using starch. We concluded that the polymers with helical structures are intrinsic to elongate the lifetime of the BR reaction. Furthermore, we found that the addition of K3[Fe(CN)6], which has a high redox activity, in the reaction solution with PVA drastically elongated the lifetime (50 min) and increased the numbers of the oscillations (nearly 100 times). This result suggests that the oxidation-reduction reactions by the ferricyanide ion promotes the redox process of iodine and iodide ions.