全國中小學科展

2010年

Mechanisms of Tumor Cell Invasion: The Role of Stat3 in Squamous Cell Carcinoma

Skin cancer, including basal cell and squamous cell skin carcinoma, is known to\r be the most common cancer type. Skin cancer is thought to make up half of all known\r cancers. Over one million non-melanoma skin cancers (NMSC) are reported every year. \r Approximately 300,000 of these cases are squamous cell carcinoma (SCC). It is\r estimated that about 2,000 people die from NMSC each year. Of the two skin cancer\r types, SCC tends to be the more clinically aggressive and likely to spread and invade,\r typically by way of blood or lymphatic vessels. Understanding the signaling pathways\r in SCC cells that regulate invasion will be important for developing improved cancer\r treatments. The signal transducer and activator of transcription 3 (Stat3) protein is a\r central regulator of numerous cellular activities, including proliferation, survival, and\r motility. Stat3 also has enhanced activity in many cancers, including skin SCC. This\r study shows that Stat3 regulates several invasive properties in a human skin SCC cell culture model.\r HGF (hepatocyte growth factor)- induced cell schattering was assessed for\r SRB12-p9 cells (p9WT), a human skin SCC cell line, along with SRB12-p9 cells\r engineered to have reduced Stat3 activity. Next, a cell viability-based adhesion assay\r was performed with these cells. Finally, severe combined immunodeficient (SCID)\r mice were injected subcutaneously with P9WT and S3DN cells and tumors were\r measured twice weekly. Extracted tumors were analyzed by immunohistochemistry and Western blotting for expression of the invasion related enzyme, MMP-2 and MMP-9.\r The suppression of Stat3 activity in S3DN cell lines resulted in reduced motility,\r greater adhesion, and a less invasive phenotype in SCID mice. Immunohistochemistry and Western blotting indicated higher levels of MMPs in the P9WT cells with\r expression localization towards the outer perimeter of the tumors. This data suggests\r that Stat3 plays a role in skin SCC invasion and better understanding of Stat3 function\r could lead to improved treatment and prevention of the disease.

The Titanium Dioxide Toilet Disinfectant

This project aims to improve the quality of toilet hygiene. The product designed should fulfill the requirements of being an environmentally friendly, user friendly and economical toilet seat system which guarantees the safety and hygiene of the toilet. This project also aims to discover the efficiency of the toilet seat system in eliminating pathogens through conducting various experiments.\r In this project, the photocatalytic property of titanium dioxide is applied. When titanium dioxide is under exposure to ultraviolet radiation, they generate free radicals, which are efficient oxidizers of organic substances. Also, research has shown that the safest ultraviolet light used will be UVA. Thus, by using titanium dioxide paint under exposure to ultraviolet light to oxidize pathogens and toxins, the aims will be achieved. Other than that, experiments will be conducted to explore the efficiency of titanium dioxide under exposure to UV radiation in eliminating pathogens by counting the number of bacteria on the toilet seat system after different time intervals the seat system has been turned on.\r The procedure of constructing the product includes drafting the product, purchasing the appropriate apparatus and materials, constructing the prototype, and checking if the product fits the goals set. Lastly, improving the design based on the flaws found during the checking procedure, as well as checking the product to see if it fits the original goals set.\r The procedure of the experiments aimed to explore the efficiency of titanium dioxide under exposure to UV radiation in eliminating pathogens conducted includes\r counting the number of bacteria on the toilet seat system after different time intervals by inoculation of bacteria on the agar plates.\r Test results showed that the number of bacteria had a steady and notable decline after different time intervals. Results also showed that bacteria would be thoroughly terminated after the system had been turned on for at most one hour. The information was then used to set the delay timer to restrict the amount of time the ultraviolet lamp was turned on to save energy.\r Moreover, the toilet seat system has also been improved so that it will complete the automatic cleaning procedure even without the user lowering the toilet seat. This improvement was made so that the product could be more convenient to toilet users.\r The system also deodorizes the toilet as the oxidization of bacteria and organic substances reduces the putrid odor released by them when they carry out chemical reactions.\r In conclusion, the project succeeds in accomplishing the goals set and is capable of improving the quality of toilet hygiene, especially in common households. The project is also successful in finding out that the toilet seat system is efficient in eliminating pathogens.

台灣的黯化現象與形成因素探討

本研究在探討台灣的黯化現象與形成因素,黯化現象為太陽輻射量到達地表的減少現象。我們藉由比較西元1961~ 2008年間,台北、台中、台南、大武、蘭嶼、花蓮六個測站的各項氣象因子進行分析處理並探討其變化情形與成因。 \r 研究結果顯示,台灣地區的都市測站(台北、台中、台南)日照時數、日照率、全天空輻射量均呈現先下降後上升的趨勢,顯示1961至2000年間確實存在黯化現象,而在鄉村測站(大武、蘭嶼)則有微幅改變但較不顯著。並藉由可能影響黯化現象各氣象因子的比對,發現最高溫的增加幅度遠小於最低溫,可能表示黯化現象部分削弱了暖化現象。另外,溫度均較差也逐年縮小,亦可以當成黯化現象的一個顯著的指摽。在造成黯化現象成因中,污染物和雲量最為明顯。在有雲量的影響下,台灣地區汙染物濃度對黯化現象的影響程度,依序為硝酸鹽類>PM10>二氧化硫,此外少量污染物也會使雲量大幅增加,故兩者對黯化現象會產生交互影響。由雲量改變量對應日照時數改變量/雲量改變量的分析圖中,可看出都市地區年平均雲量改變量大於15%時,其雲量每減少10%,日照時數約減少3~22%;若年平均雲量改變量小於15%時,則對黯化現象不具統計意義。取每年十月中雲量在1以下的天數來分析各污染物對全天空輻射量影響,可發現雲量極低時,單位污染物濃度對黯化現象影響,SO2最大,NOx次之,PM10最小。

極速火龍-利用軟片顯影法觀測氫爆的火焰傳遞

用塑膠軟管作為氫爆安全反應器,從封閉端點燃氫氧預混氣,管中火焰\r 傳遞快速,肉眼難以觀察,因此研製「氣爆顯影記錄器」來觀測,如下圖,\r 光纖導引偵測點的火光至暗箱,記錄於高速旋轉的軟片,從光電轉速計讀取\r 轉速,軟片沖洗後量測各顯影間距,可得火焰位置與時間的關係圖,量測時\r 間最小刻度可達2. 2 微秒。\r 解讀軟片的顯影,得知氫爆初期,火焰加速傳遞,大部分在25cm 位置\r 左右,火焰的速率出現急速飆升(爆燃轉變為爆震),而且火光亮度也急速升\r 高,有時火焰速率出現飆升過高,再回降趨於穩定?的現象,在50 cm 位置\r 左右,火焰進入等速傳遞階段,此階段有穩定的火焰模型,火焰頂端的亮度\r 最高,往後亮度遞減。

A Novel Contrast-Enhanced Brain Mimicking Hydrogel for Testing Implantable Brain Electrodes

Paralysis is a debilitating disorder that does not currently have safe and effective treatments. Implantable brain electrodes can be used to read brain waves and convert them into a corresponding motor function to restore movement in paralyzed patients. Tissue deformation induced around the implant site is believed to reduce their viability through the foreign body response. Developing electrodes that minimize deformation is challenging because the mechanical aspects of deformation are not fully understood and non-animal tissue models for testing electrodes are unavailable. Development of pre-clinical models for in vitro testing of the mechanical properties of electrodes can lead to a better understanding of this prevalent problem. The objective of this study was to construct a novel contrast-enhanced, brain mimicking hydrogel using photopolymerizable polyethylene glycol (PEG) polymer that contains alginate microspheres with enclosed gadolinium (Gd) contrast agent. 1.5% alginate microspheres were constructed with enclosed Gd-DTPA-BSA contrast agent and successively added into 10% PEG. Then, this mixture was photopolymerized using a 5 mW/cm2UV lamp to result in a successful brain mimicking hydrogel. Rheological testing showed that its elastic modulus was approximately 1.5 kPa, which is similar to that of a normal human brain. The model is valuable because the presence of the contrast agent in the hydrogel resulted in distinct bright spots on the MRI. This can facilitate the visualization of tissue deformation caused by electrode insertion via comparison of pre-insertion and post-insertion images. This brain-mimicking model has the potential to improve understanding of neural deformation from electrode implants in order to assist patients suffering from paralysis.

Pleistocene mammals of a river basin of Adycha

The paper represents the results of study of remains of mammalians which inhabited the Adycha-River basin (Verkhoyansky Region) during the Pleistocene Epoch. All studied materials belong to the Museum of Paleontology and Ethnography of the Adychinskaya Secondary School. For a long time, People have been finding ancient animal bones on the Adycha-River banks, and since 1955, the teacher, Bozhedonov Nikolai Gerasimovich, has been organizing exploring local lore expeditions for school children purposed for mammoth fauna investigation and material collection for the school museum. In this research collected material was classified, measurements of the Pleistocene Period animal bones were made. On the basis of it we came to conclusion that during the Pleistocene Epoch, very rare species of animals inhabited the Adycha-River basin. To our opinion, the Adycha-River basin is a unique site for research activity. Comparative measurements of the Pleistocene Periods animal bones were made. Of flu work we know measurements of the Early and Middle Pleistocene Period elephant’s bones which inhabited the Adycha-River basin. Elephants inhabited with mammoth. To our opinion, they didn’t yield to size to mammoth. In that time the Adycha-River basin, was been inhabited by camelopard, bison and Soergelia.\r Museum has 2 skull’s fragments and ovibos fronts part of horny stream. Geological age which is Early Pleistocene or late Pleistocene. These bones concern to Praeovibos. Distance between horns is more 100 mm. If we compare with ovibos skull of the Late Pleistocene we see that distance between horns is longer for the 10 time. We couldn’t found such comparisons at scientist’s works. It results that the more distance between horns is longer the more ancient, and skull’s sizes are much less.\r 7-8 km lower of Betenkes, in disclosing “?????? ???????” and sand bank “??????”, was been founded 3 crag’s part of skull of Soergelia, metacarpal bone and 2 skull’s fragments with horns part. On the Adycha-River basin was bun founded above all quantity of soergelias remains.\r In the Pleistocene Period inhabited a lot of horses. Which remains he have now. Our horse’s height in crest is from 142 to 156 sm. And what about of horses of the Early Pleistocene, it is more than 230 sm.\r Molar teeth of the Early Pleistocene Epoch horse are more for the 2.5 times than of contemporaneous analog.

A.L.E.R.T

My project ‘Avert’ (To avert and vertebrae combined) involves research into posture related back problems and a solution to help prevent back pain by maintaining correct posture. My solution is a chain-like structure fitted with 24 sensors that is sewn into a Skins compression top. When worn the chain is aligned with the user’s spine from the lower back to the base of the neck and moulds to the spine as it moves. As everybody’s back is slightly different it is important that the device can recognise the difference between what may be bad posture for one person, yet relatively normal for another. To solve this the device takes an initial reading of the user’s spine in correct posture and saves it as a reference measurement. Bad posture is defined by the device as angles that exceed the natural movement of individual vertebrae and their platelets. While in use the 24 sensors are continually measuring the shape of the user’s spine and comparing it with the original reference measurement taken earlier. If any measurement links to unhealthy posture a light will flash and an alarm will sound either aloud or through headphones until the posture is corrected. This device can be worn during light activity and non contact sports to encourage the user to maintain correct and healthy posture. The device can also record and save poor posture measurements that can be uploaded later to a software program I designed to draw the shape of the spine as a vector diagram. The device can also be plugged directly into a computer so that the user can see the shape of their spine as it moves in real time. I, along with others, tested my solution with many activities and found Avert to be a beneficial and reliable product as it successfully detects slouching and many potentially problematic spine shapes. Throughout my research I gained a thorough understanding about the potential damage bad posture can cause and the endless number of activities it occurs in. With further development I feel there is a huge potential for Avert to become a marketable product used not only for posture correction in everyday activity, but for many other purposes such as physiotherapy, biomechanics and athletic performance. Many people have approached me with praise and requests for the Avert system which is extremely exciting and also rewarding to know that my research has the potential to help people.

SPYNIK

Nikhil’s technology studies main client told him how she had no idea about how to\r stop her children looking at all sorts of website and asked him for a solution to a\r problem he initially thought was impossible to crack. Nikhil has definitely ‘cracked’\r this one: with a dedicated website his clients can log into and monitor what is going on in any computer the little box of electronic tricks is plugged into from anywhere in the\r world. This unit controls the electronics and stores the history of the web pages that the user has visited. Not only that, the client can cut the internet (and re-connect it) to the remote computer at will. At the heart of Nikhil’s box of tricks is a web-server module (The Wiznet) and a powerful microcontroller, the AtMega32. Nikhil has designed the\r board, connected the electronics and written the code to allow it to communicate with\r the computer and remote client.

Association of a Novel Hsp70 Species with Brain Aging and Proteasome Dysfunction

Most neurological diseases are characterized by the presence of protein aggregates,\r suggesting that aberrations in protein homeostasis are associated with neuronal demise. In eukaryotic cells, protein homeostasis is maintained by the chaperone, ubiquitin proteasome (UPS) and autophagy systems. As age is a risk factor for several types of neurodegenerative diseases, the function of these various protein homeostatic systems could become compromised with age. To understand the events that occur during normal aging, we examined the expression of key markers associated with the aforementioned systems in mice aged 1, 3, and >18 months. We found that proteasome activity and the amount of proteasome-related structures remained unaffected with age. Interestingly though, an agerelated increase of a novel Hsp70 chaperone protein species (herein designated Hsp70*) was observed. The expression of Hsp70* is also increased markedly in cells treated with pharmacological agents that promote proteasome inhibition, suggesting a functional interaction between the chaperone system and the UPS. Taken together, our results suggest that there is some form of crosstalk between the chaperone system and the UPS involving the observed HSP70 species.

Carbon nanotubes as efficient nanosieve for controlled assembly of nanoparticles

In this work, techniques to explore the capabilities of multi-walled carbon nanotubes\r (MWNTs) in sorting nanoparticles (NPs) were presented. A droplet of a solution comprising of quantum dots (QDs) with various sizes was deposited on an aligned array of intertwined MWNTs. Photoluminescence (PL) and fluorescence microscopy (FM) revealed that MWNTs were effective nano-sieves that could effectively sort out QDs with a size difference of ~ 2.1 nm.\r Cadmium Selenide/Zinc Sulfide (CdSe/ZnS)core-shell QDs and Cadmium Sulfide (CdS) QDs were used to explore whether chemical properties of NPs affect the sieving capability of MWNTs. Further investigation on the effects of micro-patterning on the sieving ability of MWNTs was also carried out.PL and FM results suggested that micro-patterning could aid in separation of QDs and thus improve sieving capability of MWNTs. With the above findings, QDs emitting different colors as a result of size difference could efficiently be assembled onto the MWNTs en route to three-dimensional architectures with controlled assembly of NPs.\r Together with controlled laser power to remove desired amounts of QDs decorated MWNTs, a multi-colored display could be achieved. Further experiments were also carried out to determine the feasibility of introducing MWNTs as filters for NPs. Dilute solutions containing NPs such as gold colloid was run through these MWNTs filters by gravity. Field emission scanning electron microscope (FESEM) images of the samples showed that MWNTs were successful in trapping the nanoparticles. Explorations into the length dependent effect of using MWNTs as filters, suggested that 300μm MWNTs are better nano-sieves compared to 50μm MWNTs.