重金屬錯影響細胞生理功能的研究
儘管鍺在電子工業上被廣泛運用,但對於暴露在鍺化合物所產生的毒害則尚未被詳細的探討。在探討鍺對細胞所產生的生理影響中,我們使用了二氧化鍺 ( GeO2)和有機鍺( Ge-132 )。由實驗結果顯示, GeO2,會造成人類子宮上皮癌細胞( A 431 ) 及巨噬細胞株( Raw264.7 )死亡,而 Ge -132 對細胞生長則不造成任何影響,為了進一步了解鍺引起細胞死亡是否是經過細胞凋亡(apoptosis ) ,我們將鍺處理過的細胞進行染色體 D NA 的分析,結果發現細胞中 DNA 染色體沒有斷裂。由先前 Huang 等人於 1999 年的研究結果顯示,砷對細胞所造成的毒性是經由有絲分裂活化酵素( MAPK )傳導路徑,所以為了解鍺誘導細胞死亡的路徑,我們亦分析 MAPK 傳導路徑是否亦參與其中,我們發現 GeO2加入 A431 細胞後,會活化有絲分裂活化酵素中的 ERK ,但對JNK 及 p38 皆無影響,在對蛋白質表現方面,轉錄因子 c-Jun 的蛋白質表現也是隨著GeO2加入的時間增加而上升。 GeO2加入 Raw 264 . 7cell 後,會造成 JNK 、 ERK 的活化,同樣的轉錄因子 c- Jun 也會增加,由此一結果得知鍺對細胞的影響會因細胞的不同而有所差異,為了分析自由基是否參與砷及鍺所造成細胞死亡的過程,我們分析在 A431 細胞中可產生的 NO 的可誘導性 nitric oxide synthase ( iNOS )的表現,我們發現氧化鍺及砷都會誘導 iNOS 的表現量增加。綜合以上結果,可能顯示氧化錯可能會經由 M A PK 訊息傳遞路徑來促使細胞的死亡,並且 iNOS 亦可能參與此過程。就我們所知,這是第一個提出重金屬所造成的毒害可能會經由 iNOS 來誘導產生的研究。
Despite the extensive use of germanium (Ge) in the electronic industry and optical devices, the potential risks of exposure to germanium compounds have not been evaluated. The effects of germanium on cell physiological functions were studied. We first asked if germanium oxide (GeO2) or carboxyethylgermanium (Ge-l32) could affect cell viability. We found that GeO2, but not Ge-l32, reduced cell viability in a dose-dependent manner in epidermoid carcinoma A43 I and macrophage Raw 264.7 cells. In order to test whether apoptosis contributes to germanium cytotoxicity, DNA fragmentation was evaluated in A43 1 and Raw 264.7 cells treated with GeO2 or Ge-132, respectively. We found that neither GeO2 nor Ge- 132 had effect on chromosomal DNA fragmentation. Previous studies by Huang (1999) et al indicated that sodium arsenite (NaAsO2) cytotoxicity is mediated through mitogen-activated protein kinase (MAPK) pathways. In order to study the mechanism(s) by which GeO2 mediates cell death, we analyzed the signal transduction pathways triggered by GeO2 We found that GeO2 stimulated the extracellular signal-regulated kinase (ERK) activity and transcription factor c-Jun in a time-dependent manner, but not c-Jun amino-terminal kinasc (JNK), or p38 MAPK in A431 cells. Treatment of the Raw 264.7 cells with GeO2, induced activities of ERK, JNK and c-Jun in a time-dependent manner. Collectively, these results suggested that GeO2 effects might be cell type specific. To test whether free radicals were involved in NaAsO2 or GeO2 mediated cell death, the expression of inducible nitric oxide synthase (iNOS), which produced the NO free radical, was determined in A431 cells treated with NaAsO2 or GeO2. We found that expression of iNOS was induced in a time-dependent manner in NaAsO2 or GeO2-treted A431 cells. Taken together, our results indicated that GeO2-induccd cell death may be mediated through MAPK signal pathways and that iNOS may contribute to NaAsO2 or GeO2 mediated cell death. To our knowledge, this is the first report that iNOS may contribute to heavy metal mediated cytotoxicity.
電容超音波膠體金粒子電位調控系統研發
費曼曾說:There is plenty of room at the bottom。喬治亞理工大學的Mostafa El-Sayed 教授發表的癌細胞辨識、與科學月刊報導『台大抗煞一號』引發我們對膠體金粒子的興趣。膠體的性質主要是由界達電位 (zeta potential)決定。參考台科大、成大、中山…等超音波應用研究,提出改良篩選物理法製造之膠體金粒子的儀器設計與製作。經沉降過濾可達平均粒徑 100 nm;而離心式篩選機與超音波管式篩選機可達平均粒徑30 nm。篩選後的膠體粒子以電容原理調控膠體金粒子之界達電位 (zeta potential),成功地從-30 mV 提升至-59 mV,並發展成電容超音波界達電位控制儀(Capacitor Ultrasonic Zeta Potential Controller)。以膠體金粒子與蛋白質鍵結量來測試調控界達電位的效果,發現蛋白質鍵結量之增加曲線與界達電位的增加曲線的增加趨勢相似;此功能的發現對於生物科技方面的應用應會有很大的幫助。透過界達電位控制系統,本研究達到費曼先生所期望的「在原子或分子的尺度上來加工材料和製造設備」。“There is plenty room at the bottom.” The words of Mr. Feynman are the beginning of nano technology. Mostafa El-Sayed, a professor of Georgia Institute Technology, identified cancer cells through nano gold-antibody complex. So, our study focuses on the zeta potential of colloidal gold particles. At first, the filtering method and equipments were developed. The theories were based on the ultrasonic studies of universities such as National Taiwan University of Science and Technology. Then the colloidal gold’s sizes were filtered to100 nm through settling. At last, by using Continual-Filtering Centrifuge (CoCe.) and Tube Well Mass (TW-MS), the mean particles sizes can be filtered to 30 nm. The most important results are: Zeta potential of the gold colloid was controlled with Capacitor Ultrasonic Zeta Potential Controller. The zeta potential can be raised from -30 mV up to -59 mV, which is -20 mV higher than the conventional pH-changing way. The function of zeta potential to protein binding quantity was tested. The increasing curves of zeta potential and protein binding quantity were similar. This property would be a significance of biotechnology. Thourgh Capacitor Ultrasonic Zeta Potential Control system, the zeta potential’s limitation of gold colliod, which is produced by SANSS (Submerged Arc Nanoparticles Synthesis System), can be controled in a wilder range. The study which is focused on nano-scale, like the wish of Mr. Feynman – “To manufacture material and produce equipment in atom and molecular scale”.
東沙島海灘的變遷與復育:由龍擺尾停擺說起
政府最近公佈在東沙群島設立第一個國家海洋公園,顯示國人重視海洋資源的保育與復育;但是東沙島特殊的自然景觀「會擺動的沙嘴」—龍擺尾,卻因興建八座消波塊構築的突堤而消散停擺。本研究以一個高中生的觀點,設計及進行一系列的模型實驗,探討東沙島的形成機制、各種環境因素對海灘及龍擺尾的演化、驗證龍擺尾的現況及如何讓龍擺尾復活,再由東沙島海灘復育看世界的海岸問題。雖然設備很克難,但都能完成預定的目標,證實東沙島的海灘演化。希望此次對東沙島海灘的研究成果與初步探討,能應用於世界上遭受侵蝕而需復育的海岸。In 2007, our government proclaimed Dongsha archipelago as the first national marine park, signifying her emphasis on the conservation and restoration of marine resources. However, the sand spit on Dongsha island, a unique natural wonder commonly referred to as the “swaying dragon tail”, has become motionless since the construction of a total of eight groins along its SE and NE coast during the period between 1993 and 1996. This study has conducted a series of model experiments to verify several fundamental issues, ranging from the formation and the factors affecting the stability and the status quo of Dongsha island and its spit. The experimental results find several favorably outcomes, giving the coast evolving evidences of Dongsha island. Furthermore, strategy to stabilize the coast and revitalize the spit are then considered, which could hopefully benefit the coast suffering erosion on the world’s coastline.
耐熱性酵素生產菌Bacillus Subtilis WLA12 之分離與定性
本實驗針對一取自台北縣烏來南勢溪下游之溫泉菌,進行微生物學、生物化學、分子生物學三方面之觀察與實驗,期能得到一可生產特定酵素之菌種,且具耐高溫之抗逆境能力。對其酵素進行定性,並嘗試轉殖出相關基因,使之可大量表現。目前已篩選出一種可生產多種酵素之菌種〔依其採集地點暫稱WL-A12〕經菌種鑑定為Bacillus subtilis WL-A12。藉由菌落檢測法以及Zymogram 的方式做酵素分析,並以電導轉形等技術,希望能成功轉至E. coli 上表現。另外,也對該菌種作了一些基本微生物方面的觀察〔如需氧情況、最適生長溫度〕。We isolated enzyme-producing thermophilic bacteria from hot springs near downriver of Nan-shi, Wulai, Taipei (北縣烏來南勢溪). Through microbiological, biochemistry and molecular biological analyses, a multiple enzyme-producing Bacillus subtilis strain, designated WLA12, has been isolated. The growth condition of WLA12 was observed. Using basic colony assay and zymogram analysis (gel electrophoresis) to observe the expressed enzymes, molecular weight and gene size of the enzymes were revealed. With comparison to E. coli control strain, the related enzymes were only found in WLA12. To express the Bacillus genes in E. coli, molecular cloning and gene transformation via electroporation was carried out.
遞迥數列及渾沌現象
給定一個P∈(0,1),令k0=0, p0=p,定義k1為能使 的最小正整數k,而 ; 相同的,對於給定的kn-1, kn 為能使的最小正整數k, 。若存在kn 使得,則稱p∈ In; 若對於所有n 與kn ,,則稱p∈ I∞。如此區間(0,1)可分解成集合I1,I2,…,I∞。