两株高效烃降解菌的筛选、鉴定及降解特性

为获得可用于石油、农药污染生物修复的高效烃降解菌,以高黏度的超稠油为唯一碳源,从大庆油井采出液中分离和筛选烃降解菌,并通过残油族组分及全烃组分的分析,拟阐明这些菌株的烃降解特性。结果表明:菌株H11和W14对黏度为普通稠油30倍的超稠油有良好的乳化分散能力,经16SrRNA基因序列比对分析,初步鉴定这2菌株均为铜绿假单胞菌Pseudomonas aeruginosa,接种这2菌株后,培养液中稠油的饱和烃相对含量均降低20%以上,其中接种菌株H11后,沥青质的相对含量也降低5%;同时,H11和W14对长链烃类的降解范围较广,分别最高可作用至C26和C28碳链长度的化合物,并对烃组分有代谢利用选择性。显示了这2菌株具有良好的烃类降解能力,可为石油、农药污染物生物修复提供优良的菌种资源和应用前景。     

二齿茎长蠹生物学特性研究

二齿茎长蠹1年1代，以成虫在虫道内越冬。3月下旬至4月中旬是成虫危害期，主要危害栾树和国槐的幼树主干及大树枝条，危害直径0．4－2．0cm，危害株率达80％以上，株虫口密度37头／株，成虫平均爬行能力为每公钟87．8cm，平均每头成虫日排出木屑量0.0618g。     

安徽黄山山苍子香精油成分GC-MS分析

采用美国Finnigan公司GC2000／Trace MS Plus型GC—MS联用仪，对安徽黄山产山苍子香精油进行了组分分析。共分离出63个峰，鉴定出46个化学单体组分，占组分总量95．98％，其中含α-柠檬醛36．82％，β-柠檬醛31．33％，柠檬烯11．59％，甲基庚烯酮2．56％，α-蒎烯1．73％，芳樟醇1.72％，β-蒎烯1．36％，莰烯1．05％等单萜烯或倍半萜烯。并与广西、湖南、贵州产山苍子油化学组分进行比较，发现被鉴定出组分种类数有明显差异，柠檬醛和柠檬烯的含量也不同。这种组分种类及含量的差异与品种、地理条件以及测定仪器有关。     

生长鸡胫骨对过量镁的后效应

蛋雏鸡采用玉米豆饼型日粮,添加过量镁(MgO),结果胫骨中镁含量增加,钙、钠等元素含量降低,钙:磷、钙:镁、磷:镁的比值减小,在育成期转饲正常日粮,通过成骨及溶骨作用,经过3～6周时间,胫骨中镁、钙、钠、磷的含量及他们之间的相互比值都恢复正常。     

International regulatory considerations pertaining to the development of stem cell-based veterinary medicinal products

Stem cell-based products (SCPs) are an emerging field of veterinary medicine that focuses on the regeneration, repair, or replacement of damaged tissues or organs. However, there are some issues in applying the traditional regulatory guideline for the approval of SCPs as veterinary medicinal products. This article describes the positions of Korea, US, and EU regarding SCPs, and compares the regulatory guidelines of each country for their safety evaluation. Although there are some differences in the regulatory guidelines, similar considerations in identifying the quality of SCPs and their safety has adopted. Overall, these guidelines need to be harmonized among countries.     

不同母质发育水稻土N2O消耗潜力及环境影响因素

土壤是N2O的源和汇,在淹水和厌氧条件下具有消耗N2O的能力。稻田土壤长期处于淹水状态,为N2O的消耗提供了有利的环境,从而减少了N2O排放。目前,有关稻田土壤N2O排放的相关研究已有很多,但关于稻田表层土壤N2O的消耗能力及其与环境因素之间的关系研究较少。研究采集了第四纪红壤母质发育的壤土、湖积物砂土发育的砂质壤土、冲积土发育的粉砂质黏壤土3类土壤的各3个表层(0～5 cm)水稻土,风干后将其回填至具有5 cm深土柱的培养装置内,在土柱底部添加N2O和添加氦气(He,对照)两个处理,于28℃下恒温淹水厌氧培养96 h。培养期间监测各土壤N2O、N2的动态变化,以及培养前后土壤养分的变化,量化N2O消耗量和N2增量,以期揭示稻田表层土壤N2O的消耗能力及其与环境因素之间的关系。结果表明,土壤剖面积累的N2O有95.01%～99.92% 被稻田表层土壤吸收,其中被还原为N2的N2O量占总消耗量的64.50%～83.64%,表明淹水厌氧状态下,不同的水稻土均具有很强的N2O吸收和消耗能力。研究还发现,3类土壤N2O的消耗存在一定差异,其中影响砂质壤土N2O消耗的主要环境因子为土壤砂粒含量,且两者之间存在显著的线性相关关系(R2=0.964,P=0.000);土壤黏粒、粉砂粒、pH是粉砂质黏壤土N2O消耗的主要环境影响因素,其中土壤黏粒与其消耗量呈显著线性相关(P<0.05);土壤速效钾和铵态氮增加量是影响壤土N2O消耗的主要环境因子,其消耗量与速效钾之间在0.01水平上显著正相关。这些结果表明,土壤可溶性有机碳、土壤质地、土壤速效钾等是影响稻田土壤N2O消耗的重要环境因子,且不同土壤N2O消耗的环境影响因子存在差异,这将为调节土壤N2O排放提供重要参考。     

Evaluation of a canine small intestinal submucosal xenograft and polypropylene mesh as bioscaffolds in an abdominal full-thickness resection model of growing rats

We evaluated the biological scaffold properties of canine small intestinal submucosa (SIS) compared to a those of polypropylene mesh in growing rats with full-thickness abdominal defects. SIS is used to repair musculoskeletal tissue while promoting cell migration and supporting tissue regeneration. Polypropylene mesh is a non-resorbable synthetic material that can endure mechanical tension. Canine SIS was obtained from donor German shepherds, and its porous collagen fiber structure was identified using scanning electron microscopy (SEM). A 2.50-cm² section of canine SIS (SIS group) or mesh (mesh group) was implanted in Sprague-Dawley rats. At 1, 2, 4, 12, and 24 weeks after surgery, the implants were histopathologically examined and tensile load was tested. One month after surgery, CD68+ macrophage numbers in the SIS group were increased, but the number of CD8+ T cells in this group declined more rapidly than that in rats treated with the mesh. In the SIS group, few adhesions and well-developed autologous abdominal muscle infiltration into the SIS collagen fibers were observed. No significant differences in the tensile load test results were found between the SIS and mesh groups at 24 weeks. Canine SIS may therefore be a suitable replacement for artificial biological scaffolds in small animals.     

冷害胁迫下3个狗牙根品种抗寒性比较研究

对冷害胁迫下3个狗牙根Cynodon dactylon品种的抗寒能力和超氧化物歧化酶(SOD)、过氧化物酶(POD)及POD同工酶的变化进行研究,结果表明:根据低温下细胞膜的伤害程度,3个狗牙根品种抗寒能力的强弱顺序为新农一号狗牙根C.dactylon cv.Xinnong No.1>喀什狗牙根C.dactylon cv.Kashi>矮生天堂草C.dactylon×C.trasvaalensis,且在根茎上反映更加明显;POD,SOD的活性均表现出先上升后下降的趋势,植株抗寒能力的强弱可能与它们的活性及其持续时间的长短有一定的正相关性;聚丙烯酰胺凝胶电泳表明,抗寒性越强的狗牙根品种POD同工酶条数也越多,且在冷害适应中未有新的同工酶谱带出现.     

民间信贷成因及政策研究

资金供求缺口催生了民问信贷。民贷具有潜在的制度变迁效应，也蕴涵着较大的金融风险。本文在分析民贷成因及影响基础上，针对金融表象问题和深层次体制的矛盾，提出了采取“堵”、“疏”结合的方法，诱导地下金融浮出“地面”，建立民营化金融机构的对策建议。