Residue depletion of decoquinate in chicken tissues after oral administration

Wang, Z.‐Y., Cai, C.‐Y., Chang, X.‐H., Fei, C.‐Z., Qiu, M.‐Q., Jiang, S.‐X., Xue, F.‐Q., Zhang, L.‐F. Residue depletion of decoquinate in chicken tissues after oral administration. J. vet. Pharmacol. Therap.  36 , 116–121. A rapid, sensitive, and reliable high‐performance liquid chromatography tandem mass spectrometry (LC‐MS/MS) method was developed and validated for the analysis of decoquinate in chicken tissues. The compounds were extracted using acetonitrile by liquid–liquid extraction (LLE) and purified with an Oasis^? HLB solid‐phase extraction (SPE) cartridge. Chromatographic separation was performed on an XTerra C₁₈ reversed‐phase column with a mobile phase of water containing 0.1% formic acid and acetonitrile. The analyte was detected by tandem quadrupole mass spectrometry after positive electrospray ionization by multiple reaction monitoring. The detection and quantitation limits were 1 and 2.5 μg/kg, respectively. The recoveries of edible tissues ranged from 85.3% to 104.9%, with relative standard deviations (RSD) lower than 10.4%. The depletion profile of decoquinate was studied in healthy chickens after oral administration of feed containing 27.2 mg/kg decoquinate for 10 consecutive days. The residue concentrations of decoquinate in chicken muscle and liver were detected using the developed method. The highest residue concentrations were attained 0.25 day post‐treatment, and decoquinate residues were still detected 5 days postmedication in the tissues examined. The developed method has been successfully applied to the depletion study of decoquinate in chicken tissues. The recommended withdrawal period with oral administration based on our research is 3 days.     

AC4原料药含量的HPLC测定方法研究

为建立测定AC4原料药含量的高效液相色谱(HPLC)测定方法,色谱柱:Diamosil C18色谱柱(4.6 mm×250 mm,5μm),流动相为甲醇-0.2%磷酸水溶液,65∶35(v/v),流速为1.0 m L/min,检测波长251 nm。结果显示,AC4浓度在20~200μg/m L范围与峰面积呈现良好的线性关系,回归方程A=43743ρ+26 016,R2=0.9999(n=5),平均回收率100.3%,RSD为0.54%,样品至少在8 h内稳定。表明该法快速简捷、准确度高,适用于AC4原料药含量测定。     

海北种群麻花艽闭合花冠对雌性适合度的影响

采用野外人工控制实验和观察相结合的方法，对麻花艽海北种群闭合花冠对花雌性适合度的影响进行了为期两个月的研究。研究结果表明：(1)自然状态花人工补充授粉后，破冠组在种子数目，结实率和种子重量等方面明显低于对照组；(2)在永久性闭合发生后去冠的自然传粉花朵的种子数目和结实率和对照组相对比没有显著差别，而对种子重量和发芽率有极明显的影响。综合考虑，麻花艽闭合存留花冠提高了雌性适合度，增强了麻花艽对高寒环境的适应能力。     

The Fractal Nature of Wood Revealed by Drying

An experiment on wood drying at different temperatures was conducted to show the fractal nature of the pore space within wood. Cubic blocks made from ginkgo (Ginkgo biloba) and Chinese chestnut (Castanea mollissima) wood were used. Samples were dried in oven at the temperature of 20, 40, 60 and 100 ℃, respectively. All the drying procedures lasted four hours. The mass was weighed and the dimensions were measured immediately for each sample when every procedure of drying ended. The fractal dimensions of the samples were obtained from the measurement. Results showed that the fractal dimensions increased with the drying temperature from 20℃ to 60℃ and the fractal dimensions keep a constant in the main. Results from different species and for different temperatures suggested thefractal dimension was a new parameter to characterize the porosity of wood.     

长宁苦竹种群结构和地上生物量研究

本文研究了长宁苦竹的种群结构和地上部分生物量。结果表明：（1）人工经营和未经营的苦竹种群都为增长型种群，但人工经营苦竹种群落结构简单；（2）人工经营苦竹种群径级结构偏大；地上部分生物量较大；（3）在种群水平，长宁苦竹地上部分生物量为37．58t／hm^2，随径级增大而增大；（4）在构件水平，1a生苦竹的地上生物量为1074．20g／株，2a生的为2041．86g／株；（5）1a生苦竹竿、枝和叶的含水率普遍高于2a生。     

利用大麦基因芯片筛选簇毛麦抗白粉病相关基因及其抗病机制的初步研究

利用大麦基因芯片筛选差异表达基因并结合RT-PCR分析技术，对簇毛麦的抗白粉病机制进行了初步研究。基因芯片杂交试验获得了抗病簇毛麦非诱导叶片、抗病簇毛麦和感病突变体经白粉菌（Blumeria graminis f. sp. tritici）诱导叶片的基因表达谱。抗病簇毛麦经白粉菌诱导前后的表达谱及RT-PCR分析结果表明，抗病簇毛麦中乙烯和水杨酸信号途径的部分基因被白粉菌诱导增强表达，参与了白粉病的抗性过程。另外，通过比较诱导的抗病簇毛麦与诱导的簇毛麦感病突变体的表达谱并结合RT-PCR分析，发现感病突变体中乙烯和茉莉酸途径的部分基因被白粉菌诱导表达参与防卫反应，未观察到水杨酸信号途径参与防卫反应的证据。同时对抗、感簇毛麦经白粉菌诱导不同时间的叶片进行了内源水杨酸含量的测定，结果表明抗病簇毛麦经白粉菌诱导后水杨酸含量明显上升，而感病突变体中水杨酸含量始终处于较低水平。由于乙烯信号途径是抗、感簇毛麦中共同的信号途径，而水杨酸途径只在抗病簇毛麦中参与抗病反应，所以在簇毛麦的抗病过程中，水杨酸途径是一种最有效的信号传导途径。还筛选出一批与簇毛麦抗白粉病相关的基因，包括病程相关蛋白基因、防卫反应基因、转录因子、信号传导因子和抗病基因类似物等。     

Effects of intermittent high glucose on apoptosis and PTEN expression in islet cells

AIM: To investigate whether the increase in PTEN expression is related to apoptosis, and whether it is regulated by reactive oxygen species(ROS). METHODS: The rat islet cells were divided into constant low glucose group (group L), constant high glucose group (group H), glucose fluctuation group (group F), low glucose after high glucose group (group HL) and low glucose after fluctuation group (group FL). The ROS level, apoptotic rate, intracellular calcium, insulin release and PTEN protein expression were analyzed. RESULTS: Compared with groups H and L, the insulin secretion decreased, and intracellular calcium, ROS level, PTEN protein expression and apoptotic rate increased in group F (P<0.05). Compared with group H, the intracellular calcium, ROS level, PTEN protein expression and apoptotic rate in group HL decreased, but were still higher than those in group L (P<0.05). Compared with group F, the intracellular calcium, ROS level, PTEN protein expression and apoptotic rate in group FL decreased, but were still higher than those in group L (P<0.05). CONCLUSION: Glucose fluctuation can cause the apoptosis of islet cells more easily than constant high glucose. This may be related to the change of intracellular calcium and increase in oxidative stress which promotes PTEN expression. The recovery of glucose level to some extent relieves oxidative stress, decrease PTEN expression and reduce cell damage.     

水分胁迫对楠木幼苗抗逆生理特性的影响

以1年生楠木实生苗为试材,研究测定了楠木在不同土壤含水量条件下相关的生理指标,以期为楠木幼苗的培育及应用提供参考。结果表明:由土壤干旱和水涝引起的水分胁迫都会对楠木幼苗的生理特性产生不同程度的影响,但变化趋势大致相同,表现为楠木幼苗的叶绿素含量降低,丙二醛(MDA)含量明显上升,超氧化物歧化酶(SOD)活性、过氧化物酶(POD)活性和可溶性蛋白质含量都随着胁迫时间的延长表现为先升高后降低的趋势。表明楠木幼苗对由土壤干旱和水涝引起的水分胁迫都具有一定的适应性。     

黄土区不同地类土壤容水量与渗水率的试验研究

通过对研究区12种不同土地利用类型土壤容水量和渗水率的试验研究,分析了相同土地利用和不同土地利用方式下土壤容水量和渗水率的差异。结果表明,相同土地利用方式下,农坡地土壤容水量差异约1倍,差异较大;旱梯田土壤容水量差异可达35.23%,差异明显;荒坡地相差仅为5.84%,差异较小;沟台地差异不明显。不同土地利用方式下,土壤入渗性能差异显著。在连续入渗180min时,YL（人工杨树林地）、HF（荒地整地后封管1a自然草地）、NT（人工柠条林）、SJ（人工沙棘林）、YS（人工油松林）、ZK（针阔混交林）土壤容水量分别是HP（荒地）的108.19%,173.43%,157.76%,192.28%,93.64%和129.67%。沙棘林、柠条林等人工灌木林地的土壤容水量大于人工乔木林地。荒坡经过隔坡水平台整地封闭保护自然恢复植被1a后,土壤容水量高于多数乔、灌木林地,是一种经济有效的水土保持措施。土壤容重是影响土壤容水量的主要土壤物理特性指标,土壤容重越大,土壤容水量越小。土壤含水率在9.60%～19.02%范围内对土壤容水量的影响不明显。     

基于光温效应的杨梅生育期模型的建立与验证

 根据杨梅发育对光温的反应过程,利用不同的地点、年份和品种试验资料,建立了以光温效应（Photo-thermal effectiveness,PTE）为尺度参数的杨梅生育期模拟模型,并运用独立的数据对其进行验证。结果表明,模型对杨梅雌花序出现、雌花开放、展叶、坐果、果实成熟等生育期所需天数的模拟值与实测值之间的回归估计标准误差（RMSE）分别为2.51、1.83、2.68、2.70和2.45 d;与以有效积温法（RMSE分别为8.02、7.81、5.46、5.40和11.83 d）和PAR日积分法（RMSE分别为8.28、11.0、8.52、5.56和6.87 d）为尺度的发育模型相比,模拟精度分别提高了8.6%和10.2%。