氧化壓力影響基因轉換表現對脂肪分化之作用
細胞脂肪分化是造成肥胖、骨質疏鬆、和糖尿病的重要前置因素。我們若要維持良好身材又想省去減肥藥的問題，那麼我們必須了解造成脂肪化的原因，才可能擁有好的預防之道。利用人類骨髓間質細胞可以分化成骨質與脂肪等細胞的特性，我們研究氧化壓力對間質細胞\r Ras基因轉換表現後骨質與脂肪分化的影響。結果發現以添加超氧根 (O2-，l5nM)形成氧化壓力，可促進正常Ras基因表現的間質細胞朝骨質分化;相反地，超氧根會促進\r Ras基因突變而不表現的細胞，朝向脂肪分化的現象。進一步研究其作可原理，發現氧化壓力可促進 RaS蛋白質啟動細胞外訊息活化酵素(ERK)，接著驅動骨質轉錄因子(CBFA1)表現，再到骨鈣蛋白質與骨結節形成。而抗氧化酵素(超氧根轉化酵素;SOD,5OOU/ml)的作用，可以抑制正常Ras基因細胞氧化壓力下骨質分化的進行;但不能防止氧化壓力促進Ras基因突變細胞，朝向脂肪分化的作用。總結而言:Ras基因的表現與否，是決定脂肪分化的關鍵切換點;也是影響氧化壓力對間質細胞朝骨質分化的樞紐。這種基因與氧化壓力互動影響骨質與脂肪分化的剖析，將有助於提醒人們:使用抗氧化劑來調節抗衰老、肥胖、和美容時，必須是在不同情況和不同基因體質的人，有所不同。
\r Human\r mesenchymal stem cells are able to differentiate into bone, muscle, cartilage or\r fat tissues. Our preliminary study with human mesenchymal cell line (HS-5) showed\r that HS-5 cells could differentiate to bone, cartilage and muscle but not fat cells\r as determined by histochemical staining of phenotypes. We have further studied the\r influence of oxidative stress on the switch between bone and fat cell differentiation.\r Results showed that oxidative stress started with exogenous superoxide, produced\r by the interaction of xanthine oxidase and hypoxanthine, promoted the differentiation\r of osteogenic lineage showing expression of osteocalcin and bone nodule formations.\r The mechanism was investigated and superoxide was found to induce ERK (extracellular\r regulated signal kinase) activation; and then the expression of osteogenic specific\r transcriptional factor (CBFA1). A plasmid containing ras-mutant (Ser 17 Asn) which\r can inactivate the expression of ERK was transfected into the HS-5 cells for studying\r the influence of oxidative stress on ras-mutated mesenchymal cells. Surprisingly,\r it was found that oxidative stress did not promote osteogenesis but it enhanced\r adipogenesis from the ras-mutated HS-5 cells. Further studies indicated that superoxide\r neither induced ERK activation nor CBFA1 expression, but it did enhance expression\r of adipogenic specific transcriptional factor (C/EBPα) and lipoprotein lipase in\r the ras-mutated mesenchvmal cells. Taken together, the study model to induce the\r bone cell differentiation from human mesenchymal stem cells may be employed to make\r bone cells for tissue engineering.
聚苯胺導電高分子在鐵系金屬防蝕上的應用與研究
聚苯胺導電高分子的發展蓬勃迅速，其應用也愈趨廣泛，金屬防蝕為其可能應用之一。台灣四面環海，工業發達，造成金屬腐蝕損害嚴重。本文為探討聚苯胺導電高分子在鐵系金屬防蝕上之應用，針對以下各點進行研究： ( 1）探討導電高分子聚苯胺性質與合成方法（2）探討聚苯胺導電原理（3）測試不同腐蝕條件下聚苯胺的防蝕效果（4）探討聚苯胺防蝕原理（5）各種氧化還原態聚苯胺防蝕效果之比較。實驗結果顯示塗布聚苯胺與未塗布聚苯胺之鐵系金屬（生鐵、不鏽鋼、鍍鋅鐵）在 3 ％氯化鈉、 0 . 5M 鹽酸、1M 鹽酸溶液中之腐蝕狀況，以鹼式中問氧化態聚苯胺（ Emeraldine base 。）最具防蝕效果。聚苯胺防蝕機構包含阻隔防護、腐蝕抑制劑、陽極保護、惰性化、形成保護性氧化物薄膜、阻礙離子擴散速率、電化學介面遷移等機構 ·The development and application of the conducting polymer polyaniline is getting prosperous and popular. One of the applications is corrosion protection. Because Taiwan is surrounded by sea and the pollution of industry is more and more serious than before the damage of corrosion is greater and should be properly controlled. In this paper, the authors attempted to study the effect of the corrosion protection of polyaniline in ferrous metal. This study could be divided into four parts: (1) the study of the property and synthesis methods for the conducting polymer polyaniline, (2) the conduction theory of the polymer polyaniline, (3) The corrosion protection effects of the polymer polyaniline under different corrosion situations, (4) the corrosion protection theory of the polymer polyaniline, and (5) the comparison of the corrosion protection effects of various polymer polyanilines. According to the experimental results the Erneraldine-based polyaniline gets the best corrosion protection effect. The mechanism of corrosion protection may be the result of the following ones: barrier protection, corrosion inhibitor, anode protection, innobeling, chemical active layer. inhibition of diffusion rate, and the shift of electrochemical interface.
平面上三點集中度判別法之探討
關於平面上若干點的集中度之定義，一直很少有人予以仔細的探討，因為判別的方法有很多種。本研究是以平面上三點所構成的三角形之三頂點作討論，分別以三角形的面積、周長，內心、外心和重心至三頂點距離，三點的標準差及平均差的概念，作為不同的判別方式，並以動態幾何化版ＧＳＰ模擬不同的判斷方法做為研究，在利用統計學上的方法，找出哪一種定義方式最為適合、誤差最少的判斷方法。There are many ways to determine the centralness of three dots on a plane; however, no definition study has been applied. In this study, we focus our interests on the entralness of three vertices of a triangle formed from three dots on a plane. Various methods such as the relationship of area, and the distance of the triangle to the centralness of three dots, the distance from the interior point, exterior point, the barycenter to the vertices of triangle, and the standard error and differences average obtained from three dots were determined with a dynamic geometry software GSP, and a statistic method was used to find a least error way to determine the centralness of three dots on a plane.
臭氧事件日-氣象與地形對臭氧於近地大氣層之生成與傳輸影響
2001、2002 年監測資料被用以探討風場、時間、地形對臭氧傳輸影響。完成沿海地區與盆地內各二次採樣分析，探討各污染物與風場之垂直變化，及地面臭氧分布與風場變化。結果顯示各月份與全年之日間，其相對濕度與O3 相關度最高，日照次之。提高濕度，最能抑制[O3]。夜間NO 與O3 的相關度最高，濕度次之。臭氧事件日時：(1).11:00 即可產生高臭氧，(2).沿海地區在臭氧事件日仍保持低[O3]， (3).盆地效應改變風場，使近山地區[O3]居高不下，(4).因處O3 不斷被吹入，沿海地區傍晚時之[O3]下降速度減緩。臭氧事件日之O3 生成速率R 與消失速率常數L 被求出，其中14:00 後之R 與L 值均由正值轉負值，顯示大氣反應型式明顯轉變。R 與L 值在14:00∼15:00 間最小，係因O3 反應生成光化學煙霧所致。16:00 後另一低R 與L 值，則可能導因O3 與微粒或水份反應。分析結果顯示：(1).污染物會隨高程而略增，最高濃度在300∼500 m 處，(2).各高程大氣均可分析出73 種主要HC，其隨高度之分布被繪出與探討，(3).低層大氣會有較多低分子量HC，而高層大氣則有較多高分子量HC。結果亦顯示： (1).盆地內[O3]、[NO]與[NO2]不僅較沿海地區高，且於各高程之變動亦較大，(2).沿海地區THC、烷、烯類均較高，且隨高程增加而增高，但在盆地內則相反，(3).二地區各高程之鹵化物、芳香族、氧化物與其他有機物之平均濃度相近，但沿海地區之濃度變動較大。探討O3 之二傳輸現象獲知：(1).風吹向盆地內時，[O3]隨風向遞增，R 與L 會由12:00 之正值，轉為14:00 之負值；(2).風由盆地內外吹時，[O3] 隨風向遞減，R 與L 值提前於12:00 即為–202.561 與–1.621，但14:00 時R 與L 值增大為–76.411 與0.244， (3).風向並非決定[O3]的主要因素，地形與環境因素才是。實驗結果證實：(1).不同HC 會影響O3 之生成與消失，(2).改變[NO]o 對[O3]影響不大，但高[NO]會使得[O3]下降略緩，(3).降低HC 與[NOx]雖可使 [O3]略降，但提高濕度最能抑制[O3]，(4).在O3 的衰減量上，[O3]隨濕度增加而快速降低，但衰減率則隨[O3]o 的增加而降低。一個臭氧之統計模式被建立，臭氧與水反應速率常數與速率式也被求出。
The monitoring data were used to investigate the effect of surface wind, time, and terrain on the transformation of ozone. The sampling and the analysis in the coastal and in Taichung basin were completed. The vertical distribution of O3, NOX and HC and the different altitude wind were investigated. The contour of O3 and surface wind with 3D map were plotted. The results show that the correlation behaves relativity of relative humidity with ozone is the best, and solar radiation is the next. Enhancing environmental moisture can efficiently decrease ozone concentration. In each ozone event day are: (1) the high [O3] always starts from 11:00, (2) the ozone concentration on the coastal is always low due to the high humidity, (3) the high [O3] in the east of the basin is due to the basin effect which causes changes the surface wind, and (4) in the evening, the descend rate of [O3] in the coastal area is lower because ozone blows into the coastal area. The formation rate (R) and disappear rate constant (L) of the ozone event day were obtained. The values of R and L change from plus to minus before 14:00. The values of R and L are lower at 14:00∼15:00 due to the photochemical smog formation. And another lower R and L value before 16:00 may be due to ozone react with particle or water. The results of analysis indicate that: (1) the concentration increases with increasing altitude, and the maximum is at 300∼500 m height, (2) 73 kinds of hydrocarbons were identified, and the concentration variation with altitude was also investigated, and (3) most of low molecular weight HC are at lower altitude, otherwise high molecular weight HC are at higher altitude. The results also show that: (1) [O3], [NO], and [NO2] on the basin are not only lower than on the coastal, but also their variability of concentration are big, (2) THC, paraffins, and olefins on the coastal are higher than on the basin, and the concentrations increase with increasing altitude on the coastal, but on the basin is decreasing, (3) the average concentrations of halides, aromatics, oxides, and others are similar on both area, but concentration variability on the coastal is obvious. Two types of O3 transformation was investigated, the phenomenon indicts that: (1) when wind blew into the basin, [O3] increased with wind direction. The value of R and L change from positive (12:00) to negative (14:00); (2) when wind blew out of the basin, [O3] decreased with wind direction. The more small value of R (−202.561) and L (−1.621) appeared at 12:00 earlier. But the value of R and L will become bigger to –76.411 and 0.244; (3) ozone concentration does not just dependent on wind direction., topography and surrounding conditionsa are more important effect. The experimental results show that: (1) ozone formation or disappearance depends on different HC, (2) the effect 2 of [NO]o is small for ozone photochemical reaction, but [O3] decreases with increasing [NO], (3) the descend rate of O3 depends on high humidity more than different kinds of HC or [NO], and (4) the descend amount of ozone increases with increasing humidity strongly, and the descend rate of ozone decreases with enhancing [O3]o. A statistical model was developed. The reaction rate and rate constant of ozone reaction with water were also obtained.
Molecular and Cellular Responses under Hypoxic Stress among Rice Cultivars with Different Flooding T
全球暖化造成水災頻繁，嚴重威脅植物生存。看似耐淹水的水稻，在完全淹水下亦有其生存危機。水稻FR13A 因耐水性極佳而常用於分子育種，IR64 產量高卻不耐水。是那些特質使稻種間有不同耐水機制？我們觀察其幼苗淹水24 小時後生長情形、通氣組織 (aerenchyma) 變化及應用即時反轉錄聚合?鏈反應 (real time RT-PCR)，研究酒精醱酵的主要蛋白質：乙醇脫氫? (alcohol dehydrogenase, ADH1, 2) 及丙酮酸脫羧? (pyruvate decarboxylase, PDC2) 基因之表現量。兩種水稻的胚鞘及根都因淹水減緩生長，以FR13A 減緩最明顯。通氣組織在淹水期間都有增加，FR13A 中的形成近似於對照組，IR64 則明顯較差。FR13A 中ADH1 及ADH2 在淹水一小時後迅速增加60 至100 倍，IR64 僅增加10 至20 倍。PDC2 在IR64 中表現量的增加幅度較大，但最大值仍小於FR13A 之基礎表現量。由此可知，FR13A 在完全淹水時成長減緩而原有通氣組織則持續生長，且酒精醱酵中的基因有獨特誘導反應，因此耐水性較佳。藉由此研究揭開水稻細胞及分子生物學上的耐水反應策略，將可更精準地改良稻作使其對抗淹水逆境，解決未來因環境造成的糧食危機。Global warming increases the frequency of flooding, which drastically reduces the growth and survival of plants. Although rice (Oryza sativa) appears well-adapted to flooding of roots as it is often farmed in paddies, problems arise when the whole plant is submerged in water. I am interested in the structural and molecular responses that result in different submergence tolerances in rice cultivars. Indica rice FR13A is submergence-tolerant and frequently used in molecular breeding for this trait, while IR64 is a high-yield but submergence-intolerant cultivar. In this study, I monitored the growth rate, aerenchyma formation, and gene expressions of the carbohydrate metabolism in FR13A and IR64 seedlings subjected to submergence for 24 hours, by means of real time RT-PCR and microarray. FR13A had prominently inhibited coleoptile growth and sustained levels of aerenchyma formation whereas IR64 did not. The mRNA levels of alcohol dehydrogenase 1 (ADH1) in FR13A was induced prominently, while ADH2 was induced in IR64 during early hours of submergence. The induction of pyruvate decarboxylase 2 in FR13A was stronger than IR64. The expression of sucrose synthase was similar in both strains. Expressions of the genes involved in anaerobic carbohydrate metabolism were also studied by analyses of microarray data. My findings demonstrate that elongation quiescence, persistent aerenchyma formation and shifts in anaerobic carbohydrate metabolism gene expressions are beneficial strategies of FR13A towards submergence. Through elucidating the molecular basis of coordinating submergence tolerance genes as this study provided, it will be possible to discover multiple traits associated; hence crop improvement for flooding tolerance could be achieved.
聚苯胺導電高分子二次電池之研製及性能研究
塑膠一向被認為絕緣體。但Heeger，MacDiarmid，以及Shirakawa證實，塑膠可以被改製成電的良導體。這須在高分子合成的過程中，使碳鏈呈現單、雙鍵交錯排列情形。此外，高分子也須加以摻雜(doped)，換言之，電子必須在氧化過程中被移除或在還原過程中被加進聚合物。電子移除所留下的電洞，或新加進的電子則可自由在分子鏈上移動，形成導電性。我們所要製備的導電高分子二次電池就是由這個原理完成的。所謂的二次電池(Secondary Cell)簡單的定義就是「可反覆充電、放電，循環使用的電池」，我們將會將其與市售電池比較，並改良出合適商品化的高分子二次電池。我們將以聚苯胺做為我們電池的正極，並用鋅片(原本我們要用鋰金屬的，但其再空氣中即易氧化，因此改採鋅)做為負極，製成一聚苯胺二次電池。The plastics is thought to be a insulator, but Heeger, MacDiarmid, and Shirakawa had proved that conductivity of plastics can be improved by doping other media. The conjugated polymers such as polyacetylene、polyaniline have the interlaced single-double bonds that electrons can move from one side to another side caused the production of electric currents. The purpose of this study is try to study the application of the conjugated polymer polyaniline to make a secondary battery. First, we use the chemical and electrochemical method to compose the polyaniline. Then we test the conductivity of the produced polyaniline and test the current and electrical potential of the polymer battery. The battery that we made from our laboratory has the electric potential about 0.5 volts and the electric current is greater than 50 microamperes. Finally, we also try to use the lithium as cathode to improve the performance of the polyaniline battery.
聚球藻 RF 一 1 品系生物時鐘之特性
我們成功的用溶氣計偵測到了聚球藻 RF-1 在 28℃下光合作用的概日韻律。和傳統的研究方法比起來，這個方法具有連續偵測的優點，減少因不斷取樣所造成的影響，此實驗可觀察到聚球藻 RF-1 溶氣量之變化圖與一般藻類（如單殼縫藻）不同.在光 /暗條件下 RF-1 之溶氣量的增加與減少均呈週期性變化，而且此變化現象在進入連續照光後仍然可以維持兩個循環以上，這些結果顯示以溶氣計連續偵測聚球藻 RF -1之概日韻律是可行的，而且所得到的變化圖形遠比傳統方法（於不同時間取樣）所得者自然。本實驗同時發現含聚球藻之培養液的溫度，在進入黑暗週期時會有明顯的上升，由於其變化程度比其他藻類明顯，如加以探討應有助於對此藻以及其韻律特性之瞭解。We successfully detected the photosynthesis circadian rhythm of the prokaryote Synechococcus RF-1 under 28℃ by a DO (Dissolved-Oxygen) meter. The advantage of this method, comparing with the traditional methods, is that it can detect signals continuously, reduce the influence of discrete sampling. The DO curves of the Synechococcus RF-1 are different from that of other algae. Under Light/Dark conditions, the DO values of RF-i increased and decreased periodically. The periodic phenomena progressed over two cycles under constant lighting conditions. These results revealed the feasibility of using DO meter to continuous detect the circadian rhythm of the Synechococcus RF-1 The detected DO curves looked more natural than those obtained in the traditional discrete-sampling method. We also found that the temperature of the culture increased in dark cycle. Since the variation is clearer than that of other algae, further investigation will benefit the understanding of the Synechcoccus RF-i and its circadian rhythm.
耍「薛骰」-Sicherman Dice 的探討
George Sicherman discovered that it is possible to take a couple of 6-sided dice re-labeling them with different positive integers (1,2,2,3,3,4) and (1,3,4,5,6,8) having the same probability distribution as rolling a standard pair of 6-sided dice. Such unique pair of dice is calling Sicherman dice. The secret behind the Sicherman dice can be studied by combining the powerful mathematical tool “Generating functions” with the symbolic manipulation software “Derive 6”, The same procedure may be applied to studying the possibility of the generalized Sicherman dice along the consideration of :\r (1) Adding more dice. (2) Changing the number of faces. To this end, we introduce the concept of the Sicherman Bound. For a given integer n, the number of n-sided Sicherman dice is finite. We computed manually such numbers for n?50 based on the method of “Elimination of negative terms”. Sicherman Dice 就是一對點數配置與正常骰子(6 面正立方體，點數為1到6)不同的骰子，它所拋擲出的每一種不同點數和(2,3,4...,12) 的機率恰好與一對正常的骰子相同。這種骰子是美國的Col. George Sicherman 所發現的。 Sicherman 更進一步指出：在不使用Sicherman Dice 的情形下，不可能找到一組大於或等於三顆的非正常骰子，它們拋擲出的每一種不同點數和的機率恰好與一組同數量的正常骰子相同。本研究的目標在於1. 尋求計算「Sicherman Dice 的組合和正常的骰子有相同的出現機率」的方法2. 證明Sicherman 結論的真偽及是否適用於其他正多面體(4 面/ 8 面/12 面/ 20面) 的標準骰子3. 修正Sicherman 的結論，並定義Sicherman 極限(Sicherman Limit)。在假設n面正多面體(n 為自然數， n ? 50 )存在的情形下，探討每一個正多面體的Sicherman 極限4. Sicherman Dice (Crazy Dice) 的延伸探討(1) 不同面數骰子的組合，是否可以找到面數組合相同，但點數配置不同的Crazy Dice( 如4 面與6 面的標準骰子組合，找到4 面與6 面的Crazy Dice)(2) 多個面數相同或不同骰子的組合，是否可以找到面數、個數及點數配置皆不同的Crazy Dice ( 如3 個4 面標準骰子組合， 找到2 個8 面的Crazy Dice)在研究的過程中，我發現以下的現象：(1) Sicherman Dice 的產生，是生成函數因式重新組合的結果(2) Sicherman Dice 是否存在，則視上述重新組合的結果是否有負項產生由於上述的觀察，我使用自行發展的「負項消去」法來檢驗Sicherman 結論的正確性及求得n 面正多面體其對應的Sicherman 極限。同時我也和Col. George Sicherman 取得聯繫， 討論當年他發現Sicherman Dice 的經過及其結論的限制條件，作為本研究未來發展的參考。