科展作品檢索
探討粒線體如何參與調控細胞內鈣離子訊息傳遞
鈣池調控鈣離子內流(store-operated calcium entry, SOCE)是非興奮性細胞中最主要的鈣離子通道。當內質網缺乏鈣離子時,位在內質網上的STIM1(Stromal interaction molecule 1)便會改變構型與在細胞膜上的ORAI1(Calcium relaease-activated calcium channel protein1)接合,激活SOCE的路徑。近來的研究顯示,粒線體會影響SOCE的活性。已知平均有5%-20%的粒線體藉由連繫蛋白與內質網相連。又已知內職網在缺乏鈣離子時會移動至細胞膜附近,故我們認為粒線體有很大的機率藉由連繫蛋白與內質網一同移動至細胞膜並透過吸收鈣離子的機制來調控SOCE的活性。 在使細胞表現特定螢光蛋白的前提下,我們透過活體細胞攝影來觀察特定對象(粒線體、粒線體內鈣離子)的動態變化。 從實驗結果中我們發現:當SOCE被激活後,粒線體會移動至SOCE發生處且較靠近STIM1。又絕大部分移動至SOCE發生處的粒線體同時也會吸收鈣離子。 過去的研究已證實,當粒線體與內質網之間缺乏鈣離子時,SOCE的活性會降低,且當粒線體內膜的主要鈣離子通道MCU(Mitochondria calcium uniporter)缺乏時,亦會導致相同的結果。又從我們的實驗可知當SOCE被激活時,粒線體會移動至SOCE發生處並吸收鈣離子。綜合上述,我們可以推論以下機制,當細胞內的SOCE被激活時,粒線體會藉由連繫蛋白與內質網一同移動至SOCE發生處,同時以吸收鈣離子的方式來調控SOCE的活性以及細胞內的鈣離子濃度。
> 更多
科展作品檢索
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。
> 更多
The Information Technology (IT) area has shown great growth in recent years, even with the economic recession that 巴西 has been through and the impact of the coronavirus pandemic. It is estimated that by 2024 the area will have a deficit of more than 290 thousand professionals. However, companies still face other difficulties in hiring, especially people who are looking for their first job in the Information Technology area. Most part of these difficulties are lack of qualified manpower and high prerequisites to fill internship or junior positions. As a result, the objective of this project is: to develop a platform that connects people who seek guidance, improvement or professional relocation in the Information Technology area with professionals that already have the experience they are seeking. The first step was a research and analysis of similar platforms in the market, whose proposal involves mentoring or professional connections, and it concluded that there are no services that fully meet the project’s proposal. In the second step, a research was done about mobile development, highlighting Flutter and Firebase platform. The third step defined the application’s features, such as suggestion of users and mentors, search for users, become a mentor, private chat, video calls, Portuguese and English languages, light and dark themes and profile customization. The suggestion of users and mentors is done by a match with the registered users, relating their areas of work (where the user has experience) and the areas of interest of each one. For the coding of the project, Flutter and Firebase technologies were used. To design the app, it followed Material Design specifications. For testing and distribution, the app was published on Play Store, Google’s Android application platform. The tests were performed by both the researcher and a selected group of users to verify if the functionalities were in accordance to what was defined in the beginning of the project. Perceiving the correct functioning of the application, the project achieved the proposed objective. In addition, it expanded its reach area, because it is possible to find users and mentors from any other area of the market.
> 更多
科展作品檢索
正N邊形等距異色之頂點最少塗色數探討
本科展作品在研究正N邊形的頂點塗色,定義相鄰兩頂點的距離為1,先設定距離m,規定若兩頂點相距m則塗不同色,求塗完N個頂點的最少色數。當只設定1個m時,我們研究出最少色數只有2與3兩種,並清楚區分出對應條件。而設定兩個m時,我們研究出最少色數有2 , 3 , 4 , 5等四種,同樣清楚區分出對應條件。最後推廣到設定k個m時,我們證出最少色數的絕對下界為2,絕對上界為2k+1。並以N、m的奇偶性細分各情況來做出更精密的上界估計。
> 更多