竹筍老化之謎
本研究是在探討收割後的綠竹筍(Bambusa oldhamii, green bamboo)的老化(aging)現象。一般人說的竹筍老了,通常是指竹筍的質地變硬,口感變差,此即是竹筍硬化的現象,而硬化的主因可能是竹筍受到逆境 (stress) 的刺激後,影響了基因表現的形態,導致纖維素和木質素的增加。竹筍採收後以不同方式處理,觀察切面的變化後發現,以0.2 M蔗糖水浸泡48小時後的竹筍,其切面比浸泡於水中或置於空氣中的竹筍切面較白,筍尖較綠且沒有枯萎的情況。不管是浸泡糖水、水或置於空氣中,都無法防止竹筍的硬化,但浸水和糖水可延緩竹筍硬化的情形,可見要防止竹筍老化,基本上要從抑制合成纖維素與木質素的酵素來著手。抽取竹筍切面處組織中的DNA並以DNA電泳分析之後發現,竹筍的DNA有被降解成小片段的現象,其大小差不多是180 bp的倍數,可見竹筍遇到逆境時也可能會有類似PCD (programmed cell death, 細胞程序性死亡) 的現象。抽取不同處理竹筍的蛋白質進行2D電泳,比較電泳結果發現,三種處理的竹筍的共同點在於減少的蛋白質幾乎都分布在等電點較低的部分。增加的蛋白質大多數分布在等電點較高的區域,這些增加的蛋白質可能和竹筍老現象與PCD有關。本研究還有兩個方向可以繼續延伸研究,第一個是將2D電泳上有明顯差異的蛋白質色點挖出,進行蛋白質定序,再從資料庫中比對,推測可能是何種蛋白質。第二個是研究抑制竹筍合成纖維素和木質素的?的方法,保持竹筍的口感,使竹筍能成為一種能外銷的食品。 The purpose of this study is to investigate and analyze the aging of the harvested green bamboo shoots. The research focused on how to prevent the aging of bamboo shoots and why green bamboo shoots become aging. The term “aging” means that the taste of bamboo shoots becomes hardness post harvest. At first, we tried to find out an anti-aging method, which is not only to keep the green bamboo shoots fresh, but also delicious. The method was to soak bamboo shoots in 0.2 M sucrose, in the water or without any treatment. After 48 hours, the cutting surfaces of bamboo shoots treated with sucrose were whiter, and their outer sheaths were greener than those of shoots soaked in the water or without treatment. The results showed that none of them can stop hardness. But the aging of sucrose- or water-treated shoots was retarded. The results suggest that inhibition of the enzyme activities involving cellulose and lignin synthesis may be required to prevent the aging of bamboo shoot post harvest. To get insight into the reason why bamboo shoots become hardness, the differences of protein patterns and DNA patterns between aging and fresh green bamboo shoots were analyzed and compared. The DNA from the bamboo tissues near cutting surface was isolated and analyzed by agarose gel electrophoresis. The results showed that DNA from shoots was partially degraded. The fragments appear as a ladder of DNA with sizes in multiples of approximately 180 bp. The presence of the olignucleosome-size DNA fragments suggest that the cells may undergo programmed cell death (PCD). The degradation of DNA was not observed in shoots treated with sucrose. By comparing the results of 2-D gel electrophoresis, it was found that some proteins with low pI values decreased or disappeared post harvest, while proteins with increased levels were detected in the high pI area. These changes in these proteins may result in the aging of the bamboo shoots. Prevention of the aging of green bamboo shoots is not easy. However, I found out from this study that soaking the bamboo shoots in the 0.2 M sucrose was a possible way to preserve them. The cutting surface of sucrose-treated shoots remained white, and the sheaths of the shoots was greener than those treated with other methods. Moreover, the degradation of DNA was not observed. However, it still cannot completely stop the aging of bamboo shoots. Reducing the enzyme activities involving cellulose and lignin synthesis may be a direct way to prevent the aging of bamboo shoots. It seems like there are many things to discover in the future.
摺紙數列-相關問題探討
1. 遊戲規則:將1~ 2m × 2n的連續正整數,由上而下、由左而右依序填入 2m × 2n的方格內。操作規則允許將2m × 2n做往右或往左或往上或往下的完全對摺,直到操作至所有單位方格均疊成一行,此同時有數字也由上而下形成一數列。2. 本研究即是探討操作完成的數列之數量與數字間的關連性。3. 我們發現:(1) 數列之數量與巴斯卡三角形有關。(2) 形成的數列必符合內文的 [ R(L) 性質]、 [ D(U) 性質]、[ R&D 性質]、[D&R 性質]。
1. Rules of thegame: Fill in order the continuous positive integers 1~ 2m × 2n, from top to bottom and from left to right in the 2m × 2n check. The operational rule allows a complete fold of 2m × 2n either rightward or leftward, or upward or downward, until all the check units pile up in a line. At the same time, all the integers form a series from top to bottom. 2. This study explores the relationship between the number of the series and the integers after the operation. 3. Our findings are: (1) The number of the series is related to Pascal triangles. (2) The series formed meet the properties mentioned in the study: [the property of R(L)], [the property of D(U)], [the property of R & D], and [the property of D & R].
同步現象的研究
In our daily life, objects and the contacts between objects they will have mutually affect each other, some initially chaotic systems after a sufficient amount of time will mutually correct each other, and finally achieve synchronization (example: the speed of bird and fish migration, market prices, infantry…), although some are unable to achieve this. We will illustrate and explain the synchronization system, its process and discover the conditions for synchronization. Using linking concepts, we will integrate the coupled map lattices with global coupling and coupled map lattices with intermediate-range models into a synchronization mode in order to simulate a synchronization system. We first used a small system of n≦50 to obtain results that will demonstrate the linking concepts: 1. The more chaotic a system, a longer period of time is required for synchronization. 2. An increase in the number of individual objects requires an increase in the range of concepts and the amount of time in order to achieve an in depth synchronization. 3. Initial concept values which randomly effect synchronization critical point conditions are not obvious in a mathematically incorrect graph. In a closer look, when we increased the synchronization to n≦400 and the number of times to t-->100,000 we discovered:1. Using the function G(x) we hoped the results from the graph after apply the function and correction able to overlap and test with “Scaling and Universality in Transition to Synchronous Chaos with Local-Global Interactions”, but the part which overlapped the measurements was not identical: 2. We can use the significance of the critical point and the Interactive Process to find the approximate value of the critical value up to 4 digits following the decimal point. 3. We can also use the approximate value to find out the range for the simultaneous conditions and the various points on the system itself, as well as obtain a negative correlation between them, and then it can be similarly expressed with using a curve. A computer can calculate values with this kind of enumerating method, even without any special resolution capabilities to quickly obtain large amounts of approximate values of simultaneous conditions, this is especially true when calculating unfamiliar systems. 日常生活中,物件與物件的接觸,彼此會互相影響,有些原本雜亂的系統再經過充裕時間的互相修正後,最後竟能達成同步(例如:鳥群、魚群遷徙的速度、市場價格、行軍步伐…),有些則不能。因此,我們試著利用描述同步系統的模型,觀察系統同步的過程,並且找出同步的條件。由連結的觀點,我們將Coupled map lattices with global coupling 和Coupled map lattices with intermediate-range 模型的優點整合成Synchronization mode 去模擬同步系統。我們先用小系統(n≦50)得到能印證連結觀點的結果:(一)、系統越雜亂,就需要稍長的時間同步;(二)、個體數越多時,各點需要更大範圍的點數去影響於每單位時間內以及更深的影響才能同步;(三)、起始值隨機影響同步臨界條件並不明顯,在誤差範圍內。更進一步,我們將系統推向n≦400 點,t→100,000 次,我們發現:(一)、在”G(x)”我們希望能將圖形經過函數修正之後能疊和,驗證”Scaling and Universality In Transition to Synchronous Chaos with Local-Global Interactions ”中的結果,但只有部分疊和,尺度不相同;(二)、可以直接利用臨界點的意義用十分逼近法求出臨界值的近似值到小數後四位;(三)、我們用近似值也能發現同步條件與系統各點本身可跳躍的數值範圍是負相關,可用曲線去近似。這種窮舉方式,交由電腦運算,不需要特別的解析能力就能夠快速且大量求得同步條件的近似值,尤其在運算不熟悉的系統時。
殊途同歸-格子點平面最短路徑和之探討
本研究從理想城鎮(Ideal City)街道開始,討論平面上相異n 點到某一點的最短距離和。經研究後發現:當n 為偶數時,則到相異n 點的最短距離和所形成的區域可能是一個點、一個線段或是一個矩形;當n 為奇數時,則相異n 點的最短距離和所形成的區域將會退化成一個點。此外,本研究將理想城鎮的街道換成正三角形的街道幾何平面,同樣是討論平面上相異n 點到某一點的最短距離和。經研究後發現:當n 為偶數時,則相異n 點的最短距離和所形成的區域可能為一個點、一個線段、一個四邊形、一個五邊形及一個六邊形;當n 為奇數時,相異n 點的最短距離和所形成的區域則可能為點、三角形的情況。假使考量各點重要性的比重,分別加權後再求最小點。研究發現無論在理想城鎮或正三角形幾何平面上,皆可將各點視為多個權數相同之點重疊於此點上,便可利用先前的方式求得最小點區域。透過這次的研究,可以利用n 個相異點到某一點的最短距離和實際應用在貨物運送的問題或是消防設施配置等問題。The present study was intended to start with the Ideal City and proceed to discuss the sum of the shortest distance between a point and n different points on a plane. After the discussion, it was found that if n is even, the formed region could be a point, a line segment, or a rectangle. If n is odd, then the formed region must be a mere point. Further, the current study transformed the Ideal City into the geometric plane of an equilateral triangle. Similar to the previous discussion, if n is even, the formed region could be a point, a line segment, a quadrangle, a pentagon, or a hexagon. On the other hand, if n is odd, then the formed region could be a point, or a triangle. The result of this study, which investigated the sum of the shortest distance of a certain point to n different points can be applied to the real life situation, such as transporting goods or distributing fire control facilities.
突變ras基因造成過度表現在骨髓間質幹細胞啟動氧自由基誘導細胞凋亡
特定基因的表現與不同氧自由基的產生,已知會影響細胞的生長和死亡。我\r 個人有興趣利用間質幹細胞體外培養擴充,以為筋骨組織再生的可能應用。因此\r 利用轉植(transfect)突變ras 基因(Glu61Leu)進入骨髓間質細胞株(HS-5 cells),來\r 控制ras 基因表現的高低,進而研究這些間質細胞隨著Ras 蛋白質表現的高低,\r 對氧自由基引導細胞生長與死亡之影響。結果發現ras 基因高度表現的間質細胞\r 生長減緩;相較於原生株平均減少62.4%。進一步研究其生長減少是否與細胞凋\r 亡有關,發現ras 基因高度表現的間質細胞凋亡確實比原生株高22.6%。探究其\r 凋亡原因,發現與caspase-3 有關但和粒腺體功能無關:因為caspase-3 有活化,\r 但是以粒腺體膜電位螢光追蹤劑JC-1 測得的膜電位卻沒有改變。追蹤ras 基因高\r 度表現的間質細胞其細胞內氧自由基的產量,發現Ras 高度表現株其細胞內氧自\r 由基明顯增加。當細胞外加入超氧根轉化酵素(SOD, 500 U/ml)去清除超氧根時,\r 對Ras 高度表現細胞的凋亡沒有影響;但是外加觸化酵素(catalase, 500u/ml)於培\r 養液中,卻可以抑制ras 基因高度表現的間質細胞內caspase-3 活化和細胞凋亡;\r 並且增加細胞生長循環促進分子Cyclin D1 的表現。從這些研究我們歸結出兩點\r 重要新發現: 1) ras 基因突變造成Ras 高度表現時,會促成細胞內特定氧自由基產\r 生,使得細胞生長減緩並進行細胞凋亡,只有特定抗氧化酵素(catalase)才能恢復\r 其異常; 2) Ras 蛋白高度表現而引導氧自由基產生的細胞凋亡與caspase-3 活化\r 有關,但與粒腺體功能無關。根據這些發現,未來我們或許可以朝調節特定氧化\r 還原反應或使用caspase-3 抑制劑去調控間質幹細胞的生長,以供筋骨組織再生\r 的應用。Certain gene’s expression as well as different species of oxygen radicals can\r affect cell growth and apoptosis. We are interested in amplifying mesenchymal\r progenitor cells for the application of musculoskeletal tissue regeneration. Thus, we\r transfected a mutant ras gene (61Glu/Leu) to change Ras protein expression in the\r mesenchymal progenitor cell line (HS-5 cells) and studied how ras expressing levels\r influenced intracellular oxygen radicals, and its relationship to cell growth and\r apoptosis. Results showed that Ras over-expressing HS-5 cells grew slower than those\r with wild type ras HS-5 cells and revealed a higher apoptosis rate. The higher\r apoptosis in Ras over-expressing cells was not related to mitochondrial dysfunction\r since mitochondrial membrane potential was normal as determined by flow\r cytometric analysis of JC-1 fluorescent staining assay. The higher apoptosis was\r related to higher caspase-3 activation. Further studies showed that Ras\r over-expressing HS-5 cells revealed a higher production of intracellular oxygen\r radicals in comparison to those with wild type ras HS-5 cells. Addition of catalase\r (500 u/ml) but not superoxide dismutase (SOD; 500 u/ml) specifically revived the cell\r growth associated with increase of cyclin D1 expression, but decrease of apoptosis\r associated with lower caspase-3 activation. Results from these studies demonstrated\r two important findings: 1) the ras gene over-expressing in a ras-mutant HS-5 cell line\r triggers a higher production of intracellular oxygen radicals resulting in higher cell\r apoptosis; and 2) the higher oxygen radicals related cell apoptosis is mediated by\r caspase-3 but not mitochondrial dysfunction. Based on these findings, we may\r propose to regulate mesenchymal progenitor cell growth for musculoskeletal tissue\r regeneration via modulation of redox reactions or caspase-3 inhibitors in the future.