乙酰甲喹及其主要代谢物在鸡体内的残留消除规律研究

建立了高效液相色谱串联质谱（HPLC—MS／MS）法用于乙酰甲喹及其6种主要代谢物的检测。将65只健康白羽鸡分为两组,10只为空白对照组,其余为试验组。试验组施以20mg／kgb．w．灌胃乙酰甲喹悬浊液,1d2次,连续3d。在给药结束后2、4、6、12、16、24、30、36、48、72、120h分别宰杀5只鸡,采集血液和可食性组织（肌肉、肝脏、肾脏和皮脂）样品。结果表明：乙酰甲喹原药在组织和血浆中迅速消除;乙酰甲喹的代谢物广泛存在于鸡的可食性组织和血浆中;代谢物的残留消除过程较为复杂,代谢物在肌肉和肝脏中残留量较多,在皮脂中残留时间最长。研究结果将有助干榍示7．酷甲喹存鸡体内的砖留消除期,律．     

杏树次生代谢物质含量与小蠹虫危害的关系

为揭示杏树次生代谢物质含量与小蠹虫危害的关系,通过对小蠹虫不同危害程度的杏树树皮和树叶中的次生代谢物质(黄酮、单宁、总酚)质量分数进行研究,用方差分析和相关性分析判断各个次生代谢物质质量分数的变化与小蠹虫危害之间的关系。结果表明:不同危害程度的杏树,叶片中这3个次生代谢物质的质量分数间均无显著差异(P0.05);不同危害程度的杏树皮中黄酮和总酚质量分数之间存在显著差异(P0.05);不同危害程度的树皮中的单宁质量分数间无显著差异。经过相关性分析,受害程度与树皮中的次生代谢物质(黄酮、单宁、总酚)质量分数呈负相关性,总酚质量分数与受害程度的相关性最大,黄酮次之,单宁最小,其中与总酚在8月的相关性最大为(r=-0.878**),与单宁质量分数相关性在6月最小(r=-0.280)。     

RNA二级结构预测算法的研究进展

在简要介绍了RNA的基础知识之后,对RNA二级结构的定义、表示方法、数据库等内容进行了详细阐述,并重点探讨了RNA二级结构预测方法的原理、适用范围及优缺点.目前,传统的RNA二级结构预测方法有比较序列分析法和最小自由能算法;新进发展的算法有支持向量机算法、基于堆积协变信息与最小自由能算法、基于局部茎搜索的算法、基于快速动态权重匹配算法、免疫粒子群算法、基于茎区的自由能算法、质心法.经过预测精度、复杂度、预测假节能力的对比,发现基于堆积协变信息与最小自由能算法和基于快速动态权重匹配算法,预测结果比较理想.     

RNA二级结构预测算法的研究进展

在简要介绍了RNA的基础知识之后,对RNA二级结构的定义、表示方法、数据库等内容进行了详细阐述,并重点探讨了RNA二级结构预测方法的原理、适用范围及优缺点。目前,传统的RNA二级结构预测方法有比较序列分析法和最小自由能算法;新进发展的算法有支持向量机算法、基于堆积协变信息与最小自由能算法、基于局部茎搜索的算法、基于快速动态权重匹配算法、免疫粒子群算法、基于茎区的自由能算法、质心法。经过预测精度、复杂度、预测假节能力的对比,发现基于堆积协变信息与最小自由能算法和基于快速动态权重匹配算法,预测结果比较理想。     

Effect of a size-based selection program on blood metabolites and immune response of Litopenaeus vannamei juveniles fed different dietary carbohydrate levels

Blood metabolites in wild and seventh-generation cultivated shrimp were measured to determine how size-based selection could alter the nutritional and immunological conditions of Litopenaeus vannamei. Wild L. vannamei juveniles and a sample of seventh-generation cultured shrimp were acclimated under identical conditions. During 55 days, shrimp were fed a high (HCHO: 44%) or a low (LCHO: 3%) carbohydrate diet for 55 days. Wild shrimp showed a direct relation between dietary CHO and lactate, protein and hemocyte levels indicating that dietary CHO was used for protein synthesis via transamination pathways. In seventh-generation cultured shrimp these parameters were inversely proportional to dietary CHO level, indicating the capacity to synthesize protein from dietary CHO was repressed in cultured shrimp. Farmed shrimp showed a limited capacity to respond to LCHO diets demonstrating high protein dependence in their metabolism and immune response. These results demonstrate that during size-based breeding programs other metabolic process than CHO catabolism can be selected. The incapacity of shrimp to use dietary CHO could limit protein reduction of diets and limit the efforts of the shrimp industry to be ecologically and environmentally profitable.     

Effects of aromatase inhibitors on reproduction in male three-spined sticklebacks, Gasterosteus aculeatus, exposed to long and short photoperiods

Three-spined stickleback Gasterosteus aculeatus, males were implanted with Silastic capsules filled with different aromatase inhibitors; 1,4,6-androstatriene-3,17-dione or the non-steroidal CGS16949 A, 4-(5,6,7,8-tetrahydrimidazol [1,5-a]pyridin-5-yl) benzonitrile monohydrochloride or empty capsules. The fish were then exposed to long or short photoperiod. Under the long photoperiod most fish in all treatments displayed a hypertrophied kidney (a secondary sexual character in sticklebacks) and completed, quiescent spermatogenesis, similar as in the natural spawning period. Under the short photoperiod the controls had unstimulated kidneys and an active spermatogenesis, whereas the males implanted with both aromatase inhibitors had stimulated kidneys, though not to the extent as in the long photoperiod, and completed, quiescent spermatogenesis. These findings suggest that aromatization is of importance for the inhibitory effects of short photoperiod on reproduction in the stickleback. This revised version was published online in July 2006 with corrections to the Cover Date.     

Site of acid-base relevant ion transfer in the gills of rainbow trout (Oncorhynchus mykiss) exposed to environmental hypercapnia

In order to delineate the contribution of primary vs. secondary circulatory circuits in the gill for acid-base and ionic regulation, the flow and composition of the fluids in the central venous sinus (CVS) and the systemic circuit of rainbow trout were studied by application of a previously developed microcannulation technique during normocapnic and hypercapnic conditions. The average haematocrit (Hct) of blood from dorsal aorta (DA) and sinus venosus (SV) ranged from 20.1 to 26.7%, whereas average Hct in the fluid from the branchial vein (BV), representing drainage from the central venous sinus (CVS), was in the range of 4.2 to 7.0%. Under normocapnic conditions, the largest fraction of cardiac output, 92.9%, was directed through the systemic vascular circuit, whereas the CVS circuit was perfused with 7.1 % of cardiac output. Hypercapnia did not significantly affect the blood flow distribution between the two circuits. The pattern of acid-base regulation in dorsal aortic blood reflected the characteristic response of fish exposed to environmental hypercapnia. Upon initiation of environmental hypercapnia (2% CO₂), plasma P_{CO 2} was elevated in all three flow compartments (CVS, DA, SV), inducing an extracellular respiratory acidosis of about 0.4 pH units. pH and [HCO₃ ^-] values in the DA were consistently lower, than those for both CVS and SV sites throughout the hypercapnic period. During the 8h of exposure plasma bicarbonate concentration was elevated by about 12 mM, complemented by a fall in extracellular [Cl^-] of about 10 mM in all three compartments. The amount of HCO₃ ^- gained at the CVS site during 8h of hypercapnia (3.3 mmol · kg^-1) exceeds the amount accumulated in the extracellular space (2.1 mmol·kg^-1), suggesting the CVS as the main site of ionic acid-base regulation in trout.     

中华绒螯蟹副性征的研究

在解剖、测量性成熟和未成熟中华绒螯蟹外部形态和性腺之基础上,试用“双百分率法”和“差异显著性检测法”对中华绒螯蟹的副性征进行了研究。结果表明,性成熟后的雌、雄中华绒螯蟹均具有较明显的副性征。     

Plasma levels of vitamin D3 metabolites during parr-smolt transformation of Atlantic salmon Salmo salar L.

Plasma vitamin D and vitamin D metabolites were measured in Atlantic salmon parr during smoltification and after transfer to seawater. The fish were fed commercial feed for 5 months under natural light, and Na⁺/K⁺ ATPase was measured as an indicator of the smoltification status. No significant differences were recorded in the level of plasma vitamin D metabolites. However, a tendency of increasing plasma concentration of 25OHD₃ and also a temporary increase in plasma 1,25(OH)₂D₃ and 24,25(OH)₂D₃ were recorded prior to seawater transfer. The minor changes in plasma levels of the metabolites indicate a role of the vitamin D metabolites during parr–smolt transformation, although we do not know whether the increased levels are caused by increased synthesis of the metabolites or by decreased binding to receptors or decreased excretion.