生物能源对饲料市场及相关产业的影响及对策研究

<正>随着石化能源的价格上涨及其所带来的环境问题,生物能源作为一种可再生能源越来越受到重视,其中燃料乙醇和生物柴油尤其被看好。目前,燃料乙醇的原料以玉米为主,生物柴油的原料以大豆和菜籽     

椰汁冰淇淋的生产工艺

研究以椰子汁为辅料生产椰汁冰淇淋的生产工艺,探讨不同椰汁用量对冰淇淋品质的影响,开发出一种含有脂肪、蛋白质、维生素等营养成分的冰淇淋,并通过正交试验确立了生产椰汁冰淇淋的工艺参数。结果表明:以25%椰子果汁、10%奶油、10%白砂糖、12%全脂淡奶粉、0.3%稳定乳化剂为配方可生产出品质优良的产品。     

池塘养殖南美白对虾试验

南美白对虾属广盐性虾类,生长快,抗病力强,肉味鲜美,养殖经济效益较高.2004年我市在阳原县三马坊利用地热水资源进行了南美白对虾养殖试验,现将试验情况总结如下:     

Isotope-dilution technique for determination of endogenous faecal excretion and true absorption of iodine in 125I labelled rats

Introduction In studies on the quantitative mineral metabolism the separation of total faecal mineral excretion into the fraction of dietary and of endogenous origin is often a methodical barrier. Both components cannot be distinguished by standard chemical procedures. But their separation is essential to the quantification of the mineral flux from the diet into the organism and back from tissues into the faecal excretion as it is necessary for example to quantify the bioavailability of dietary mineral sources (K irchgessner et al. 1993). For this purpose, the use of isotopes is an appropriate means. During the last decades, several techniques employing radioactive or stable isotopes have been developed, e.g. the ‘comparative balance method’, the ‘dual tracer’ or ‘double isotope’ technique, methods based on computerized ‘compartment analysis’ and the ‘isotope-dilution technique’ (e.g. A ubert et al. 1963; T hompson 1965; B elshaw et al. 1974; G ibson et al. 1988). Among these methods, the isotope-dilution technique, in particular, comprises direct and quantitative measurements of mineral fluxes and provides robust estimates of endogenous faecal excretions as has been shown for a series of macrominerals and trace elements (W eigand and K irchgessner 1976a,b; W eigand et al. 1986a,b; K reuzer and K irchgessner 1991; R euber et al. 1993; K irchgessner et al. 1994; W indisch and K irchgessner 1994; W indisch et al. 1997; G abler et al. 1997). For iodine however, there is no appropriate isotope method available. Therefore, the present experiment was designed to establish the isotope-dilution technique for iodine. The isotope-dilution technique is based on a single parenteral injection or a long-term oral administration of the tracer (W indisch and K irchgessner 1994). After the labelling procedure, all tracer that appears in the faeces is of endogenous origin. The calculation from the quantity of tracer recovered in the faeces to the total amount of endogenous faecal excretion of the respective element is performed by the use of a reference tissue from which the endogenous excretion originates or which is at least in very close physiological relationship to the endogenous excretion. Using ¹²⁵I as tracer the total amount of endogenous faecal iodine is calculated as follows: Endogenous faecal iodine (ng/day) = A_faeces/SA_{reference tissue}A_faeces = ¹²⁵I activity in the faeces (Bq/day)SA_{reference tissue} = specific ¹²⁵I activity of the reference tissue (Bq ¹²⁵I per ng of total iodine)True absorption of dietary iodine (ng/day) = Iodine intake – iodine in faeces (total – endogenous)In total, the present methodological study had to focus on two major aspects. Since the administered tracer needs time to reach steady-state kinetics within the excretory pool of iodine it was to be clarified at first, from which day after a single ¹²⁵I administration does the faecal ¹²⁵I excretion correctly represent the total endogenous excretion quantitatively. Secondly, it had to be clarified which tissue or body fluid may be used as a proper reference source to quantify the endogenous faecal excretion and thus to calculate true absorption of iodine.     

Homeostatic adjustments of iodine metabolism and tissue iodine to widely varying iodine supply in 125I labeled rats

Introduction   The homeostatic regulation of nutrient flow through the body is a fundamental ability of living organisms and has been shown to be active also in the case of several trace elements (K irchgessner 1993; K irchgessner et al. 1997). The basic function of homeostasis is to maintain the body's internal status of the trace elements within physiologically tolerable margins by controlling at least one of the major trace element fluxes: the true absorption of the trace elements from the diet into the body, the reflux from the body into the faeces (endogenous faecal excretion), and the urinary excretion. Furthermore iodine may be a candidate to homeostatic regulation since dietary iodine contents may vary over a wide range and it may be important to the organism to maintain a constant internal status also of this essential trace element. However, quantitative iodine balance measurements are hardly available from the literature and thus knowledge about the existence of iodine homeostasis and its mode of action is still fragmentary. An additional problem also was the lack of appropriate methods to quantify true absorption and endogenous faecal excretion of iodine. However, a recent study has overcome this methodological barrier by adapting the isotope-dilution technique to iodine (W indisch et al. 1999). Therefore, the aim of the present experiment was to quantify possible homeostatic adaptations of iodine metabolism to dietary iodine ranging from deficient to excessive supplies and to measure the interactions to tissue iodine.     

某些小麦品种抗白粉性遗传研究简报

 小麦白粉病近年在我省各地普遍发生,造成一定损失,研究明确主要品种抗白粉性的遗传行为,提高抗白粉小麦育种的效能,是一项急待开展的工作。本文简述了1983-1985年间我们对4个抗原品种在田间接种下进行抗白粉遗传研究的部分结果。     

瓜类蔬菜子叶离体培养的研究进展

本文对瓜类蔬菜子叶离体培养的研究进行综述,包括再生途径、影响因素及应用等方面研究的进展,讨论了瓜类蔬菜子叶离体培养存在的问题和今后研究的重点。     

表面等离子共振生物传感器检测培氟沙星的方法研究

研究表面等离子共振生物传感器检测缓冲液中培氟沙星的方法,为样品的检测提供依据。采用抑制法,将培氟沙星与卵清蛋白的偶联物固定在芯片上,将抗体与不同浓度的培氟沙星混合后通入芯片表面,优化反应条件,构建标准曲线。结果显示,选择1∶1000稀释的抗体,流速7 μL/min,反应时间4 min,构建标准曲线,可以达到较低的检测限。利用SPR生物传感器建立快速检测缓冲液中培氟沙星的方法,检测限为0.8 ng/mL,检测时间为4 min,为样品检测奠定基础。