灰葡萄孢诱变菌株毒素的除草活性研究

 对灰葡萄孢BC4菌株进行紫外线诱变得到了15个诱变菌株, 经测定筛选出BC4-1、BC4-2和BC4-15等3个诱变菌株中以BC4-1菌株效果最好。试验发现，用于毒素产生的PD培养基的pH 值对产毒能力影响很大，以pH 4.0最优。用三氯甲烷、石油醚、乙酸乙酯萃取培养滤液制备BC-粗毒素，生物测定结果表明，以乙酸乙酯萃取所得粗毒素对杂草种子萌发及生长抑制作用最强。通过柱层析法和HPLC法分离和纯化除草活性组分,得到1个在271 nm有最大UV吸收的化合物,该组分在100 mg·L-1浓度下对马唐的生长具有强烈的抑制作用，在50 mg·L-1浓度下可完全抑制马唐和反枝苋种子的萌发。     

青龙湾沙区土壤养分状况分析

为了研究不同植被类型对沙区土壤的改良效果,调查沙区土壤的养分状况,笔者对青龙湾沙区不同植被类型的土壤有机质、有效氮、速效钾、有效磷等指标进行分析。结果表明,青龙湾沙区土壤pH值范围为7.40~7.72,土壤呈中性略偏微碱性;土壤有机质、有效氮、有效磷及速效钾含量偏低。有机质含量对于土壤其他营养元素的含量和有效性均具有比较大的影响。不同植被类型对沙区土壤的改良具有一定的差异,除农田外,果园、毛白杨刺槐混交林的改良效果较好,小叶杨林改良效果较差。总体来说,经过生态林改良后的土壤养分状态得到明显改善。     

河北献县表层土壤全氟空间变异性特征分析

为了对河北献县土壤改良及对地氟病的防治提供指导性建议,采用地理信息系统与地统计相结合的方法对研究区表层土壤全氟的空间变异特征进行了分析。结果表明:献县表层土壤全氟经对数转换后符合指数模型,全氟具有很强的空间相关性,说明其有明显的可迁性特点,受水文地质、地形等自然结构性因素影响较大而受人为因素影响较小;用Kriging内插法对未测区域全氟进行最优估计,并形成插值图,可更直观的反映出研究区内表层土壤全氟的空间变异特征。从整体上看献县表层土壤全氟含量呈现东南西三部含量高而北部偏低的分布特征,其分布特征受河流走向影响较大且远离河床处氟含量呈渐增趋势。     

香茅草精油/羧甲基壳聚糖复合膜的性能及对沃柑采后青绿霉病防治效果

为探寻安全高效的可食性涂膜应用于沃柑保鲜,以羧甲基壳聚糖（Carboxymethyl chitosan,CMCS）和香茅草精油（XMC）两种天然材料为原料制备复合涂膜材料,并检验复合涂膜材料的理化性质,后以蒸馏水为对照,研究0.5%香茅草精油与1.0%羧甲基壳聚糖复合涂膜处理（0.5% XMC-1.0% CMCS）对沃柑果实青霉、绿霉病害的防控效果及其对果实抗病防御酶活性和果实品质的影响。结果表明,香茅草精油的添加提高了膜的韧性、完整性、粗糙度、不透明度,降低了水蒸气透过率。同时,0.5%香茅草精油与1.0%羧甲基壳聚糖复合处理显著（P<0.05）抑制了沃柑果实青霉、绿霉病的发病率及病斑直径的扩展。此外,与对照组相比,0.5%香茅草精油与1.0%羧甲基壳聚糖复合涂膜处理诱导提高了沃柑果皮中苯丙氨酸解氨酶（PAL）、过氧化物酶（POD）、多酚氧化酶（PPO）、几丁质酶（CHI）活性及苯酚、类黄酮、花青素等抗性物质的含量,且在整个贮藏过程中保持了果实品质。综上,香茅草精油的加入提高了复合膜的整体性能,0.5% XMC-1.0% CMCS复合涂膜处理诱导提高了采后沃柑果实的抗病防御酶活性和抗性物质含量,增强沃柑果实抗青绿霉病的能力,维持了果实贮藏品质。     

Electrokinetic separation of chiral compounds

Femtomole amounts of racemic mixtures of derivatized amino acids were resolved and analyzed rapidly in about 10 minutes by means of high-voltage zone electrophoresis with laser-fluorescence detection. The electrophoresis was performed in capillary columns containing a chiral support electrolyte. A number of dansyl amino acids were resolved by the diastereomeric interaction between the DL-amino acid and the copper(II) complex of L-histidine present in the support electrolyte. A combination of electro-osmotic and electrophoretic action caused all species, positively charged, neutral, and negatively charged, to pass through the 0.5- nanoliter detection volume where they were subjected to laser excitation.     

Comparative cardiovascular, analgesic, and sedative effects of medetomidine, medetomidine-hydromorphone, and medetomidine-butorphanol in dogs

OBJECTIVE: To compare sedative, analgesic, and cardiopulmonary effects after IV administration of medetomidine (20 microg/kg), medetomidine-hydromorphone (20 microg of medetomidine/kg and 0.1 mg of hydromorphone/kg), and medetomidine-butorphanol (20 microg of medetomidine/kg and 0.2 mg of butorphanol tartrate/kg) in dogs. ANIMALS: 6 dogs healthy mixed-breed dogs. PROCEDURE: Instruments were surgically inserted, and heart rate (HR), respiratory rate (RR), systolic arterial pressure (SAP), mean arterial pressure (MAP), diastolic arterial pressure (DAP), mean pulmonary arterial pressure (MPAP), pulmonary capillary wedge pressure (PCWP), central venous pressure (CVP), core body temperature, and cardiac output (CO) were measured 0, 5, 10, 15, 30, 45, and 60 minutes after injection. Cardiac index (CI), stroke volume (SV), stroke index (SI), systemic vascular resistance (SVR), and pulmonary vascular resistance (PVR) were calculated. Arterial samples for blood gas analysis were collected 0, 15, and 45 minutes after injection. Intensity of analgesia, degree of sedation, and degree of muscle relaxation were evaluated at aforementioned time points and 75, 90, 120, 150, 180, and 210 minutes after injection. RESULTS: Administration of medetomidine, medetomidine-hydromorphone, and medetomidine-butorphanol was associated with increases in SAP, MAP, DAP, MPAP, PCWP, CVP, SVR, PVR, core body temperature, and PaCO2 and decreases in HR, CO, CI, SV, SI, RR, pH, and PaO2. Clinically important differences were not detected among treatments. Medetomidine-hydromorphone and medetomidine-butorphanol provided a longer duration of sedation and better quality of analgesia, compared with medetomidine alone. CONCLUSIONS AND CLINICAL RELEVANCE: Medetomidine-hydromorphone or medetomidine-butorphanol is associated with improved analgesia and sedation but has cardiopulmonary effects comparable to those for medetomidine alone.     

魔芋种芋包衣技术研究

以膨润土、高岭土、观音土、耐火泥4种黏性较好的土样为载体,并添加一定量的魔芋包衣试剂1或试剂2、石灰、锯末等辅助材料,对魔芋种芋进行丸化包衣技术研究。结果表明,T-22(高岭土+石灰+试剂1+水+锯末)、T-23(观音土+石灰+试剂1+水+锯末)、T-25(膨润土+石灰+试剂2+水+锯末)处理的包衣表面光滑,厚度在2.1~3.6 mm,可避免种芋碰伤。与不做包衣处理(对照)相比,包衣后不影响种芋的正常呼吸,呼吸强度在108.57~113.96 mg/(kg·h);种芋过氧化物酶和多酚氧化酶活性降低,过氧化氢酶活性升高;出苗率和出苗时间差异均不显著。表明T-22、T-23、T-25是适宜魔芋种芋的丸化包衣技术。