亚贡叶中营养成分和功能性化学成分分析

亚贡[Smallanthus sonchifolius (Poepp. et Endl.) H. Robinson]为多年生草本植物[1],原产南美洲安第斯山脉,是当地印第安人的传统根茎食品, 在我国海南、台湾等地有种植.亚贡生长在亚热带气候、无霜冻、湿度大、常年云雾缭绕且海拔1 000 m以上的高山中.亚贡可生长至2～3 m,根茎在生长7～12个月后成熟.根茎中果寡糖含量丰富[2],其低热量、高甜度的特性适合糖尿病人及减肥者食用[3].     

盘基网柄菌发育中的细胞粘附分子及其信号转导

在盘基网柄菌发育早期,DdCAD-1和csA调节了变形虫细胞间的粘着,调控该过程的机制类似于胚胎发育中上皮细胞层的闭合。完成网柄菌发育的一个必需分子是gpl50异嗜性粘附分子。盘基网柄菌β-连环蛋白同源物Aardvark(Aar)的缺乏使细胞间失去粘着连接,Aar也有信号转导功能,调控了前孢子细胞基因的表达。因此,细胞间的粘着是盘基网柄菌发育的一个重要组成部分,并与调控形态发生过程的信号转导有密切相互作用关系。     

高山被孢霉的红四氮唑染色程度与菌体油脂中花生四烯酸含量的关系

研究了高山被孢霉菌体被红四氮唑(TTC)染色的条件,并探讨了染色程度与菌体油脂中花生四烯酸含量的关系．高山被孢霉的种子菌体被TTC染色的程度随种龄增加而增加,而种子中的油脂含量和油脂中的花生四烯酸含量也都随种龄增加而增加．在发酵过程中,菌体被TTC染色的程度和菌体中的油脂含量以及油脂中的花生四烯酸含量随培养时间增加而增加．三株具有相似油脂含量、不同花生四烯酸含量的高山被孢霉以及一株不产花生四烯酸的鲁氏毛霉的染色结果显示菌体被红四氮唑染色的程度与菌体油脂中的花生四烯酸含量具有正相关性．该发现有助于花生四烯酸高产菌的快速筛选．     

球形红假单胞菌反应中心中蛋白的量子化学研究

采用重叠二体近似方法和建立在从算水平上的扩展负本征值因数计算方法（extended negative factor counter method）研究了球形红假单胞菌（Rhodobacter sphaeroides(Van Niel)Imhoff,Truper et Pfennin）中兴合反应中心中蛋白链L及M的电子结构。结果表明：（1）对组成蛋白链L（M）的前线轨道有重要贡献的氨基酸残基分布在L链的自由螺旋区（M链的α螺旋区）。由于自由螺旋是有柔曲性的,它易于在电子转移的过程中改变其构象并降低体系的能量,而α螺旋结构却相对稳定,这种差别有可能是光合反庆中心中电子转移只沿L支进行的原因之一。（2）与特殊对分子及辅助叶绿素分子形成轴向配位的组氨酸残基对于特殊对P和辅助叶绿素分子的ELUMO有重要影响,但此组氨酸的相应分子轨道的贡献并没有出现在蛋白链的前线轨道组成中。这意味着色素分子与蛋白链之间的相互作用对蛋白链前线轨道的贡献没有影响,但却能影响相应色素分子的ELUMO能级。     

Photosynthesis and water relations of almond tree cultivars grafted on two rootstocks

Five cultivars of Prunus amygdalus Batsch (Ferragnes, Ferrastar, Marcona, Garrigues, and Non Pareil) grafted on two different rootstocks (Garrigues and GF677), and two cultivars (Ferraduel and Casa Nova) grafted on GF677, were grown for three years under rainfed conditions in an orchard in northeast Portugal. Net photosynthetic rate (PN), leaf conductance for water vapour (gs), leaf water potential (Ψ), instantaneous water use efficiency (WUE), and internal CO2 concentration (Ci) were measured at three periods of the growing season: spring, summer (June or July) and late summer (September) over two years. Ferraduel, Ferrastar, and Marcona presented the best performance in the periods when environmental conditions were not very hard (May or September). Casa Nova and Non Pareil were well adapted to high air evaporative demand, preventing the increase of leaf temperature (T1). Ferrastar, although having a good performance in May and September, did well adapt to hard climatic conditions in June 1994. In the following year, although it presented the highest T1, the values were not limiting (30.6 ± 2.1 °C), and PN was only decreased from May to July. Marcona was highly dependent on T1, but prevented its increasing. Garrigues showed lower PN in most measurement periods. GF677 frequently induced the highest PN, WUE, and Ψ. PN was mainly dependent on T1, radiation, Ci, month, and year. WUE depended on the same factors. Ψ depended mainly on gs, air temperature, month, and year. This revised version was published online in June 2006 with corrections to the Cover Date.     

Insulin-like 3 expression and fibrosis induction after intra-testicular injection of magnetic nanoparticles in rat testis and the ameliorative role of Echinacea purpurea extract

The World Health Organization has approved magnetic nanoparticles (MNP) for use as a contrast agent for magnetic resonance imaging or tumor hyperthermia treatment. MNP are toxic over time after intra-testicular injection. A clear strategy to ameliorate the toxic side effects of MNP in normal tissues after medical application has not yet been developed. We used an extract of Echinacea purpurea (EP) as a natural source of antioxidant and free radical scavenging product for detoxification of MNP in testicular tissues. MNP localization in the interstitial area of testicular tissue reduced the expression of insulin-like factor 3 (INSL3) proteins as well as serum testosterone levels. Further, MNP caused accumulation of both collagen and elastin in the interstitial area and increased the thickness of the tunica albuginea. Injection of MNP during administration of EP extract for short periods slightly reduced the toxic side effects of MNP. After extended exposure to EP extract, INSL3 expression and testosterone returned to near control levels. Also, collagen and elastin accumulation caused by MNP was reduced after extended exposure to EP extract. We believe that the ameliorative effect of EP extract is due to its antioxidant properties.