全國中小學科展

醫學與健康科學

Listen to Your Heart

a. Purpose of the Research Nowadays people are getting unhealthy, especially the heart. Since the outbreak of SARS, the Hong Kong citizens cared more about their health. In the past two decades, due to the technological advancement, many medical instruments that were used by doctors are now available to the public. One of the examples is the sphygmomanometer used for measuring blood pressure. On the other hand, very few heart monitoring devices are developed for public use. As a result, there is a need that such heart monitors should be available to the public. b. The device Our device is a modified stethoscope, which electronic components are added to this common medical instrument. The device mainly consists of 3 parts: 1. The sensor: modified from ordinary stethoscope, which a condenser microphone is added to change the heart sounds into electrical signals 2. The signal processor: integrated circuits and resistor-capacitor couples, which the cost is much lower than digital electronic components, are used to amplify and filter the noise in the electrical signals. The processor is divided into 3 stages: - Preamplifier: Amplifies the electrical signals converted from heart sounds - Low pass filter: Filters the noise in the signal. The cut-off frequency is 600Hz, which most of the heart sounds are below 600Hz. - Power amplifier: Amplifies the filtered signals before outputting into computers or earphones. 3. The output devices: it can be a computer or an earphone. In a computer, the heart sounds can be converted into graphs, enabling precise graphical analysis. Since many abnormal heart conditions will alter the heart sounds, with the aid of computers and graphs, people can know whether their hearts are normal or not, and can seek for medical support before developing any critical situation. Moreover, abnormal heart sounds are more significant in graphs, so any heart problems can be discovered more easily. c. Data During an exhibition in Hong Kong, about 1000 people tried the device. Among them approximately 150 people were confirmed to have heart problems with abnormal heart sounds. Using our device, we discovered 109 of them. As a result, the accuracy of the device is about 72.6% d. Conclusion With the low cost of our device (~€9.80/US$12.80), everyone would be able to afford it. As a result, people can check their conditions of their hearts more frequently, and would be able to discover any early heart problems.

Blood Brain Barrier Breached!

The purpose of this project is to determine if it is possible to use Ascorbic Acid Sodium- Dependent Vitamin C Transporter Type II, SVCT2, as an effective and safe protein to attach to certain brain tumor treatments to bypass the Blood Brain Barrier (BBB). Stemming from this problem, a procedure was created to use in vitro engineering with the aid of a professor at the University of Calgary to combine SVCT2 and three specific tumor treatments; Imatinib Mesylate (STI-571), Temsirolimus (CCI-779), and Suberoylanilide Hydroxamic Acid (SAHA). Following this, a metabolic barrier had to be created to simulate the BBB. To do this, the use of three enzymes were mixed and held together using specific bonds. Finally, a special bio-tracer was placed within the barrier to detect any toxic effects that may be produced. Then two trials were made with each treatment on the barrier at 34°C, 37°C, and 39°C. Once this was done observations could be made. When the newly isolated SVCT2 attaches to the three cancer treatments, they would all be able to connect and form bonds with each other. Once the incubation period is over for the first trial at 34°C, 37°C and 39°C, several things would be observed within the data. When counting the number of cells that were able to get into the engineered metabolic barrier, it could be seen that there was a dramatic increase in the number of cells in the 37°C range. SVCT2 can be a powerful tool in combating cancer. Because of its specificity, it may prove to be more advantageous over the currently used drugs which may have unwanted toxic side effects on the CNS. In the near future, SVCT2 could have the potential to be adopted as a promising therapy against cancer and certain tumors. Furthermore, SVCT2 has the potential to be applied to many situations and can be modified to fit a number of situations that deal with getting past the Blood Brain Barrier. Initially, SVCT2 was only modified with three forms of treatment for Glioblastoma Multiforme, STI-571, CCI-779, and SAHA, however there are countless other treatments that have been developed, but that are not in use due to the BBB. This project was successful in determining an appropriate temperature of 37°C for the procedure to be used. The limitations of this experiment include the fact that this experiment was performed in vitro and so complexity among individuals cannot be analyzed. However, this is an early step for the future of SVCT2 as a treatment, and clinical trials to test SVCT2 in vivo may not be too far off.

以交聯化羊膜為模式探討Wnt路徑保存表皮幹細胞之分子機轉

研究目的:以交聯技術改良羊膜,增進其培養並維持表皮幹細胞的效能;並以其為模式,探討Wnt訊息於基底膜上維持表皮幹細胞之機轉。 研究過程:用EDC交聯羊膜(HLE/CLDAM)、天然羊膜(HLE/DAM)或純化之基底膜蛋白培養角膜表皮幹細胞,以細胞群落形成作用分析幹細胞之保存;以免疫螢光染色法、real-time PCR及西方墨點法觀察幹細胞及分化標記之表現、β-catenin、Tcf4、Lef1、integrin β1及integrin-linked kinase (ILK) 之變化。以ILK SiRNA及cDNA分別下調或上調ILK於HLE之表現,並觀察其對Wnt相關蛋白質及p63表現之影響。 研究結果: HLE/CLDAM組比HLE/DAM組表現更高量的幹細胞群落與標記,並可見β-catenin轉移至細胞核、Tcf4及ILK之表現。加入GSK3-β抑制劑促進表皮細胞之群落形成及p63之表現。調控ILK基因可造成相對應之Wnt訊息及p63蛋白之表現。純化之基底膜蛋白活化Wnt訊息及表現p63蛋白,但產量很少。 結論:交聯化羊膜比天然羊膜更能保存角膜表皮幹細胞,其機轉為ILK活化Wnt路徑,後者再作用於p63基因,從而活化幹細胞相關因子。 運用:交聯化羊膜可取代天然羊膜培養角膜表皮幹細胞;培養基質表面的複雜性可用來調控幹細胞之分化,從而提高體外培養幹細胞之效能。

探討生物材料對骨髓間質幹細胞成骨分化效率之影響

本實驗之目的在利用骨髓間質幹細胞 (Bone Marrow Mesenchymal Stem Cells, BMSCs) 培養為平台,篩選能提升BMSCs成骨分化效率的生物材料。實驗中利用osteogenic induction medium (OIM)使BMSCs朝成骨分化路徑進行,分別在第7(前期)、14(中期)、21(後期)天作Alizarin Red Stain assay(ARS assay)測定鈣沉積之效率作為評估標準,而後於平面上塗覆不同生物材料進行測試,根據實驗結果顯示,Gelatin主要在中期就可達到最高成骨分化效率,而PCL與HA到後期亦能顯著提高成骨分化效率。當進入3D立體成骨誘導試驗時,我們發現Gelatin、HA的複合材料能保持平面之特性且結合二者優點,並且更能有效提升成骨分化之效率。

Green tea causes preventing cancer

Now a days cancer is one of the most important factor of death in the world so we decided to introduce people one of the easiest way of it’s prevention. However, the relation between green tea and cancer is not completely identified but the research shows that drinking green tea reduce the state of cancer. First we found some information about the green tea compounds then we investigated the cancer factors in different countries and stidied the experiments among 900 women showed that drinking tea reduce the state of ovary cancer. Green tea contains A, B, C, D vitamins & Fe, folic acid &also minerals such as Ca, K, Zn. This useful soft drink is a strong Anti?oxidant so prevent any kinds of cancer & blood clot. Therefore it reduce the state of heart attack. (Up to 31%) So it is not only prevention factor but also it can open a new way to cure different cancers.

嘖目稱奇的大豆卵磷脂

本研究目的是探討大豆卵磷脂對於老化及學習記憶能力是否有改善之功能。以 24 隻 SAMP8 小白鼠,分為大豆卵磷脂組及對照組,飼養 8週。經由主動迴避試驗、單次被動迴避試驗,測其學習記憶能力;另測量其腦部丙二醛(MDA)之含量,評估其老化的程度。由實驗結果顯示,在主動迴避試驗中,大豆卵磷脂組被電擊次數有減少趨勢;在單次被動迴避試驗中,大豆卵磷脂組停留在明室的時間高於對照組。而在 MDA方面,大豆卵磷脂組腦中MDA含量低於對照組。由上結果推測大豆卵磷脂對於抗老化及學習記憶方面都有改善的功能。 The purpose of this research was to study the effects of soybean lecithin on improving the aging process and learning and memory abilities. The first part of the experiment is to raise 24 SAMP8 mice eight weeks, and divided them into group A and Group B. We tested them memory power by Active shuttle avoidance test and Single-trail passive avoidance test, and tested their degrees of the aging by the content of MDA. The result demonstrated that there was a decreasing tendency in times of being hitting in group A during Active shuttle avoidance test. The time which group A stayed in the bright room was higher than group B during Single-trail passive avoidance test, and the content of MDA in group A was apparently all less than group B in the experiment of MDA. So we can get the message that Soybean Lecithin has the improvement of ameliorating the speed of oxygenation and increasing memory power.

新網路模式對抗無尺度流行病傳染A New Network Model to Fight Against Scale-Free Epidemi

流行病的傳染如同一個無尺度網路,但有一些特殊特性在發展一套新傳播模式時,是需要被詳加考慮的。我採用時間位移(t 與ti 分別以t?(ti?1)與ti?(ti?1)來取代)至無尺度網路模式中,再引入一個非連續強力函數H(t; ti?1, L+ti?1)來描述流行病傳播的特定時段與強度,並重新定義機率p 為無效傳染率。之後,我建立了新模式「無尺度流行病模式」-SFE-1與SFE-2。模擬六種病原的傳染途徑,結果證實SFE-1與SFE-2模式是正確與確切可用。案例研究結果,顯示傳染強度H可為固定值或為變數;p可以是一固定值、雙固定值或為新增病例的函數。更進一步解析美國AIDS病例在不同族群與行為上的差異,獲知亞裔/太平洋裔與印第安人/阿拉斯加人的H值低於其他族群,其原因可能是由於小的族群具有較高的接觸所致。異性性接觸的H值低於其他,顯示性交易是傳播HIV的主要途徑。SFE-1與SFE-2模式也可被用在流行病的預測上,因為SFE-2使用已知值而非估算值,所以SFE-2模擬結果較佳;但是SFE-1更可以明確提供一個流行病在失控或控制下的預測結果。無尺度流行病模式可以協助所需警戒的程度與政策決定的計畫結果。因此在幫助政府評估社會經濟成本與健康憂慮上是一個有用的工具。所以我提出一個確切可行的對抗無尺度流行病傳染新方法,並詳細說明運作流程。The course of epidemics resembles a scale-free network, but some specific elements should be considered in developing a new model. I introduced a time shifting (replacing t and ti by t?(ti?1) and ti?(ti?1)) and a discontinuous forcing function H(t; ti?1, L+ti?1) into the scale-free network model to fit the specific period and intensity of the infection, and redefined the probability p as an invalid infection rate. Then I proposed the new Scale-Free Epidemic Models, SFE-1 and SFE-2. The simulation results of six types of epidemic transmission showed that the SFE models were accurate and useful. In the case studies, the results showed that H were constant or variable, and p were a fixed constant, a dual constant, or a function of new addition cases in the epidemic periods. The further studies for comparisons of the difference races/ethnics and the difference transmission category of AIDS cases in USA were analyzed. The H value for Asian/Pacific and Indian/Alaska Native race were lower than others, it may be due to small clusters with constant high contact rates. The H value for heterosexual contact was lower than the others, indicating that whoredom was the main transmission for HIV. Both SFE models can be used to predict epidemics, SFE-2 is better than SFE-1 due to SFE-2 using given indices and not conjectured values, but SFE-1 can more clearly suggest results of epidemics when under control or not. SFE models can help the government to determine the level of caution needed and the projected results of policy decisions. They are useful tools in assisting to balance socio-economic and health concerns. I hereby propose a new method to fight against epidemics with detailed procedures of using the SFE models.

Investigation on traditional medicine from plants in Namibia

My project is about investigation on traditional medicines in\r Namibia. This is all about plants and different herbs that different\r people in Namibia use for medicinal purposes. The objective of this\r project is to inform the world of how valuable nature is and how we can\r try to conserve nature’s treasure so that valuable knowledge cannot pass\r away with olden experienced herbalists. Understandably the enquiry\r into indigenous medicinal herbs arose from the need to expand the\r possibilities of ones own medical practice. It was very important for me\r to satisfy our farmer’s thirst for knowledge, which is what I want to do\r with the rest of the world.\r In this project I have included most but not all of the plants that we\r use in Namibia for medicinal purposes. Seeing that some of these plants\r do not grow in certain parts of the country, I have also tried to clone it in\r other parts of the country. I have also made a powder from one of the\r plant’s leaves and tested it on several people within the country.\r To conclude my findings and experiments I would like to say, let us\r try to take these precious knowledge left for us from our ancestors and\r maybe one day in the future we might need it in some ways.

Keyboard for Blinds

The reason for making this project was with the intention to help the blind persons. A lot of people with vision problems don’t have the resources available to acquire equipment or programs that make it easier for them to use a computer to write, to communicate etc... Being aware of this problem we took the liberty of researching at a community center that helps the blind persons in Tijuana Baja California, Mexico. We found that they had a type writer (Perkins) with only 6 keys that symbolized Braille. They also had a normal keyboard that had the Braille code over each key, but it is complicated to learn because of its many keys. Due to our research our intention was to design a system that respect the Braille symbols of the Perkins type writer and translated them to the common alphabet. We believe that this project will help many people especially the blind, with writing books, letters, articles, etc. So they can be integrated to activities and jobs reserved, until now, for people with the sight sense. My project also has 8 keys, when the person press a key combination the PC emits the sound of the letter. And when a word is completed the PC reproduce the whole word on the speaker. When the entire paragraph is completed there is an option to reproduce it. It has also other functions as erase everything, back space, etc. All these with the 8 keys. To control the system I used the parallel port of a PC, with a control program made in Visual Basic. Currently there are systems for the blind but are very expensive, they have a cost of approximately $900.00 US dollars, which is a high price to pay for some people. My project has a cost of $70.00 US dollars thus making it easy for a person who has a computer to be able to buy this keyboard. This project is being use in the “Blind Persons Training Center” of Tijuana city. They helped us to develop it, giving some ideas to improve it.

吸菸、喝酒與嚼檳榔之基因毒性研究

流行病學資料顯示,近年來口腔癌發生率明顯增加。本研究之目的是探討口腔黏膜細胞微核發生頻率及彗星分析法之基因傷害指標是否與菸、酒、檳榔暴露有關,以及是否可以看到菸、酒、檳榔之交互作用。 研究對象為桃園地區山地鄉之民眾,利用問卷收集個人之菸、酒、檳榔及干擾因子之暴露資料,再採集樣本之口腔黏膜細胞及血液樣本,進行基因傷害評估。 結果顯示,口腔黏膜之微核發生率與檳榔之暴露相關性最大,可以解釋12.6%;然而,彗星尾部動量和尾部長度則以香菸暴露解釋力最大;同時,檳榔與香菸的基因傷害交互作用似乎存在。因此我們認為,口腔黏膜細胞之微核發生頻率對於檳榔暴露者應是不錯的基因傷害指標,而香菸暴露則以彗星分析法之指標較為敏感。 ;Epidemiological studies showed that the incidence of oral cancer increased significantly in recent years. The purpose of this study is to evaluate the genotoxicity of cigarette smoke, alcohol and betel quid use as well as the. interaction effect between these three risk factors. The study subjects were selected from residents lived in a mountain area of Tao-Yuan county. We used questionnaire as a tool of exposure measurement. The exfoliated oral buccal cells and blood samples were collected for the assay of micronucleus frequency (MNF) and comet assay. We find that there are higher MNF in smokers, alcohol drinkers, and betel quid users compared with nonusers. However, a significant difference can not be found because of small sample size. The relationship between MNF and three risk factors was strongest in betel quid use, however, for smokers the parameters in comet assay were more sensitive than MNF. There is a tendency of additive effect between cigarette, alcohol and betel quid although without statistical significance. Advanced statistical analysis is suggested to find stronger evidence in the genotoxicity biomarker.