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.
波動奇蹟—皂膜與皂水共振模式之研究
本研究探討肥皂膜與肥皂水的共振現象。在肥皂膜共振方面,我們以實驗探討皂膜的共 振模式與頻率的關係;並配合共振理論模型求出薄膜厚度,再與體積密度-厚度測量方法比 較。而又發現皂膜在共振時,皂膜保存時間較平常久,故進行皂膜生命期與頻率、強度的關 係。在進行肥皂膜實驗時,肥皂水滴落在喇叭上,振動出奇特的形狀,進而探討皂水共振的 特性並嘗試建立其數學模式。 ;The research is about the resonance of soap film and soapsuds. For the resonante of soap film, we tried to find out the relation between the resonant pattern and frequency by experiment; according to the resonante model, we measured the thickness of soap film, which was compaired with volume-dencity method. We found that the life-time of the resonant soap film is longer than the normal one, so we proceeded to study the relation between the life-time, frequency, and power. We observed special resonant pattern while the soapsuds fell down on the speaker. So we studied the characteristics of resonant soapsuds, trying to make the mathematical pattern of resonant soapsuds.
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.
吸管笛的諧音之研究與發展
吹長笛時,按同一按鍵,以大小不同的力量去吹,會引發不同頻率的泛音,而通常越用力吹,引發泛音的頻率越高,所以我們想了解為什麼越用力,泛音的頻率會高,其間的關係究竟是什麼?風經過管口會產生各種頻率的噪音,其中某些特定頻率的聲音會因為會在管內形成駐波而放大,所以我們只能聽到某些特定頻率的聲音。當風速增加時,會在管口形成渦漩逸放的紊流現象。其渦漩頻率與流速成正比(註一)。我們以塑膠管實驗。發現以特定的風速引發該基音後,繼續增加風速,當風速達某一定強度時,才會躍遷為下一個泛音的頻率。這個現象告訴我們:在一封閉管下,風速與泛音的關係並非「線性遞增」,而是越「躍遷遞增」的關係。另一個實驗測量不同管長、其諧音之頻率的關係,我們可以得知,越短的管子,因為相鄰兩泛音間頻率差較大,越不易激發更高階泛音。經由這些實驗結果,我們能夠推論:當管子越長、基音頻率越低時,諧音間頻率的差距相對越小,繪出的風速-頻率關係圖應更加顯示了風速與頻率呈正比關係。未來我們可以以閃頻器觀測紊流渦漩的產生,再變化至不同吹入角度,及各式管口造形,這些實驗能協助我們更進一步了解樂器的發聲原理,甚至開發一個以聲音頻率測量風速的儀器。註一:林婉如、張?文2006 國際科工程組佳作作品。When we press the same key and blow a flute using different strengths, we can get different overtones. Usually, the harder we blow the flute, the high the frequency we get. We want to understand why we get a higher frequency when we blow harder into the flute and to understand the relationship between them. When wind passes through the mouthpiece, many kinds of noises will be produced. Some of the frequencies will expand because they will form standing waves in the tube. Therefore, we can only hear certain frequencies. As wind speed increases, a turbulence of the vortex shedding will be formed. The frequency of the vortex shedding and wind speed will be in a direct ratio. We experiment with plastic tubes. When we increase the wind speed and get certain magnitudes, the frequency will jump to the next overtone. The phenomenon shows that the relation, in a closed tube, between wind speed and harmonics is not a linear increase but a transition increase. In another experiment, we measured the relationship between wind speed and different lengths of tubes. We can infer that the shorter the tube, the higher high-frequency harmonics can be produced. Through these experiments, we come to the conclusion that the longer the tube, the lower frequency of the fundamental tone we get and the discrepancy in frequency between harmonics is smaller. Then we make a diagram between wind speed and frequency that indicates that there is a direct ratio between wind speed and frequency. In the future, we can use “” to observe the production of turbulence. Then we can switch to different angles when we blow into flutes. Otherwise, we can experiment with different shapes of mouthpieces. These experiments can assist us to understand more how the instrument sounds. We can develop a device measuring wind speed with frequency.