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Phytochemical screening and evaluation of antiangiogenic properties of sapinit (Rubus fraxinifolius) fruit crude extracts
Plants are potential low-cost alternatives for cancer treatment. Rubus fraxinifolius or “sapinit” has been found to possess phytochemicals with anti-cancer potential. This project aimed to evaluate the antiangiogenic properties of methanolic R. fraxinifolius fruit crude extracts through the chick chorioallantoic membrane (CAM) assay. Through phytochemical screening, leucoanthocyanins, phenols, and tannins were detected. For the CAM assay, 10, 20, and 30 μg/μL extracts, distilled water, methanol, and retinoic acid were applied on 60 ten-day-old chicken eggs. The CAM photographs were analyzed using ImageJ Software. The mean percent inhibitions (MPI) of total length and vascular density from both analyses were subjected to One-Way Analysis of Variance (ANOVA). The ANOVA for the MPI of total length, followed by a Tukey post hoc test, show that only retinoic acid treatment has significantly higher MPI (p = 0.0010). Meanwhile, the results for the MPI of vascular density show no significant differences between all groups (p = 0.1630). It is possible that the concentrations used in the study may not be the concentrations needed to achieve optimal antiangiogenesis. The results may also be due to the absence of phytochemicals that exhibit significant antiangiogenic properties such as alkaloids. Lower concentrations and isolated phytochemicals may also be tested.
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消費者面對同類性質之高低價兩商品,當低價商品從原價降至零元,而高價商品同時等量降價時,消費者對低價商品之偏好將顯著增加,此現象稱為「零元效應」,因確定性效應、損失規避及稟賦效應造成。故本研究目的驗證零元效應的強度與成因,並實驗零元效應在不同消費領域、族群是否皆成立;設計不同族群受試者、實驗情況及品項分類,進行零元效應的極限測試。實驗具兩階段,形式分實際購買實驗及選擇實驗進行,其中皆設計各種變項之實驗組,對照其差異。實驗結果使用Wilcoxon 等級和檢定,並與 Dan Ariely (2007) 實驗結果進行比較,發現其差異不大;而在零元效應的極限方面發現除「必需品」外,其他品項皆存在零元效應,且受試者性別、年齡、地區不影響零元效應之強度。
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實驗室裡的飛行荷蘭人--複雜蜃景之探究 (Fata Morgana: the explanation of the 'Flying Dutchman')
複雜蜃景(Fata Morgana)專指擁有多重影像的特殊上蜃景,形成於高緯度海面上,也是「飛行荷蘭人」的主要成因。本研究主要藉由探討介質折射率梯度變化與觀察者高度位置等變因,釐清複雜蜃景形成與觀察的最佳條件。藉由控制高濃度糖水溶液擴散形成的密度梯度,我們在六十公分的水缸中重建出形成複雜蜃景的環境,主要是因為糖水溶液中的折射率梯度遠大於海面上空氣的逆溫梯度所造成之折射率變化。為了進一步解析光在複雜折射率介質中之行進模式,我們以綠雷射光入射糖溶液,在側向以相機紀錄光的行進軌跡,分析探討其折射現象。我們同時利用相機觀察放置於水缸另一側的模型船,藉以觀察實際蜃景的形成與演化。本研究中我們另發展一套光軌跡的模擬程式,以協助實驗的進行與驗證實驗的成果。藉由實驗與理論模擬相互映證,充分探討複雜蜃景的成像與形成的最佳條件。
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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.
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"When the Well is Dry, we will know the Worth of Water." Most of 埃及 and the world suffers from water and petrol shortage. With the current consumption rate, two-thirds of the world's population may face water shortages by 2025. These are water pollution, overpopulation, and agriculture, leading to wastewater from landfills and pipes that seep into the ground and may pollute the water, making it unfit for human consumption and waste more water. Besides, some accidents happen to water distribution and irrigation systems, causing a significant loss in water. According to the ministry of water resources, in 2016, the need for freshwater is 67 billion cubic meters. On the other hand, 埃及 receives only 55 billion cubic meters (2.6 billion cubic meters of them evaporate during runoff). Also, one of the wasting water methods in modern irrigation systems is water leakage from pipes as the water transmission and distribution lose about 31% of the produced water due to pipe leakage. Besides, every day more than 3.3 billion liters of treated water – 20 percent of the nation's supply and 234 million liters a day more than a decade ago – are lost through leaking pipes in England and Wales. Many reasons lead to leakage in pipes like water pressure, clogs, and corrosion. The leakage in pipes does not exist in the lines of water only. Also, the pipes in a petrol can cause dangerous accidents like the accident in the Bahira government that led to the death of 6 people and made 19 in a dangerous state. Our project designed a system that can detect fluid leakage and deal with it fast to prevent the wasting of fluid by using sensors and electronic circuits. Our system provides us with information about the fluid (like the amount of the flowing fluid and its speed). Therefore, if there is a difference in the reads, we understand that there is a leakage in this region, and the system will automatically stop the fluid flowing through the pipes. the system will locate all the leakage sites and send them to the mobile app with the amount wasted and the actions taken.
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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.
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Limited Query Black-box Adversarial Attacks in the Real World
We study the creation of physical adversarial examples, which are robust to real-world transformations, using a limited number of queries to the target black-box neural networks. We observe that robust models tend to be especially susceptible to foreground manipulations, which motivates our novel Foreground attack. We demonstrate that gradient priors are a useful signal for black-box attacks and therefore introduce an improved version of the popular SimBA. We also propose an algorithm for transferable attacks that selects the most similar surrogates to the target model. Our black-box attacks outperform state-of-the-art approaches they are based on and support our belief that the concept of model similarity could be leveraged to build strong attacks in a limited-information setting.
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THE DESIGN OF MICROFLUIDIC PUMP (MFP) FOR MEDICAL FIELD
The ability of microfluidic (MF) device technologies to provide a lot of information with a small amount of sample, the opportunities it offers increases their use in the medical field in the bedside monitoring in drug delivery systems. Three-dimensional (3D) printer technologies provide advantages such as cost-effectiveness in the production of MF devices and quick and easy production in intricate designs. In our project, it is aimed to design microfluidic pumps (MFP) to be used in the medical field and conduct its production with 3D printer technologies. The developed MFP is intended to be at low cost, bio-compatible, adaptable, and portable to the drug, suitable flow properties as a pharmaceutical pump. First of all, MFP air channel, flow channel, etc. parts were designed and printed with the help of a 3D printer and on AutoCAD, one of the professional drawing programs. The poly(dimethylsiloxane) (PDMS) membrane that will enable MFP activation is produced in different thicknesses and glued to the air channel of MFP. The resistance to the applied pressure is observed, and the appropriate membrane thickness is determined as ~ 235µm. Liquid PDMS was applied to the inner surfaces of MFP's air and flow channel, PDMS membrane was placed between them, and the parts were assembled in the oven at 60ºC. MFP has been connected to the pneumatic valve system, where operation codes have been prepared with Arduino Uno, and flow properties have been examined. The flow rate of MFP is ~ 50 µL/min at a maximum of 15 Hz, and the backpressure is ~ 0.085 Pa under a maximum pressure of 3 bar. Also, values such as size, membrane thickness, and applied pressure for the possible models of MFP were supported by theoretical calculations. As a result, MFP, which is biocompatible, drug adaptable, portable, wearable technology application potential, and has suitable flow characteristics as a pharmaceutical pump, has been developed. MFP introduced a microfluidic pump system that can make life easier for the patient and contribute to the national economy through domestic production and can be used as a drug pump in the treatment of diseases such as diabetes and cancer.
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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.
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Properties of possible counterexamples to the Seymour's Second Neighborhood Conjecture
The project is devoted to the study of the Seymour’s Second Neighborhood conjecture by determining the properties of possible counterexamples to it. This problem has remained unsolved for more than 30 years, although there is some progress in its solution. The vector of the research is aimed at the analysis of possible counterexamples to the conjecture with the subsequent finding of some of their characteristic values. In addition, attention is focused on the generalized Seymour’s conjecture for vertex-weighted graphs. Combinatorial research methods and graph theory methods were used in the project. The author determines the values of densities and diameters of possible counterexamples, considers separately directed graphs of diameter 3. The conditions under which specific graphs cannot be counterexamples to the Seymour’s conjecture with the minimum number or vertices are defined. The relationship between the Seymour’s conjecture and vertex-weighted Seymour’s conjecture is explained. It is proved that if there exists at least one counterexample, then there exist counterexamples with an arbitrary diameter not less than 3. Under the same condition, the existence of counterexamples with a density both close to 0 and close to 1 is also proved. The equivalence of the above two conjectures is substantiated in detail. It can be concluded that if the Seymour’s Second Neighborhood Conjecture is true for a directed graph of diameter 3, then it is true for any digraph, so that problem will be solved. Moreover, if the conjecture is true, then vertex-weighted version of this conjecture is true too. That is why a digraph of diameter 3 needs further research.
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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.
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Locus of the Points on Circumference of the n-th Circle that Formed by Moving the Center of any Radius Circles on the Outermost Circumference of Preceding set of Circles
This project aimed to study the motion which occurred from the end point on the circumference of the outermost circle by moving the center on the circumference of a preceding circle and the center of an innermost circle at origin. According to the study, when angular velocity was changed, it caused the different of loci. Based on the above information, finding the locus of the point on circumference of n-th circle that formed by moving the center of any radius circles on circumference of preceding set of circles was studied to get general equation. A set of circle and locus were created with GSP program. First, set the same radius circles on the X-axis with the first circle at origin, then found the relationship that occurred from the characteristics of locus. The result showed that if the ratios of angular velocity are 1:1:1, 2:2:2, 3:3:3, ..., …, n:n:n or 1:2:3, 2:4:6, 3:6:9, …,nw1:nw2:nw3, the characteristics of locus will be the same, while the others will be different. Finally, the equation of locus was found as follow: (x,y) = { ..........see in abstract...........} when .........see in abstract........... Where ri is the radius of i-th circle, zeta i is an angle between the radius of i-th circle and X-axis, wi is the angular velocity, t is elapsed time and alpha i is a starting angle between the radius of i-th circle and X-axis.
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