城市创意农业发展与品牌建设

介绍了创意农业的内涵及城市创意农业的特点,从品牌意识相对滞后、产业层次有待提高、农业资金投入不足几个方面阐述了创意农业品牌发展现状,提出城市创意农业品牌建设对策。     

SYBR Green Ⅰ法洋虫β-actin基因实时荧光定量RT-PCR体系的建立

为了建立洋虫β-actin基因实时荧光定量RT-PCR体系,本实验采用MJ Research OpticonTM2型实时荧光定量PCR仪,利用SYBR Green Ⅰ染料法,根据GenBank上其他昆虫β-actin基因的保守序列设计引物,对PCR退火温度、引物浓度、模板浓度等各反应因子进行优化,结合扩增曲线和熔解曲线进行分析.结果显示,在20μL体系下,当2×SYBRR Premix Ex TaqTM为10μL时,引物和cDNA模板的最佳浓度分别为1 μmol/L和50 ng/μL.最佳PCR反应程序为:94℃预变性30 s,44个循环包括94℃变性10s,45℃退火30 s,72℃延伸40 s,最后加做熔解曲线82℃1 s.结果表明,在洋虫不同发育时期β-actin基因表达水平基本稳定,因此β-actin基因可以作为洋虫实时荧光定量RT-PCR的内参基因.本研究成功建立了2-△△CT相对定量法的洋虫β-actin基因实时荧光定量RT-PCR体系,并分析了优化PCR反应体系的重要性,建立的洋虫β-actin基因荧光定量RT-PCR方法简便、特异性强,该体系的建立可用于洋虫蜕皮相关基因表达差异的深入研究.     

关于冻土地基的几点思考

随着寒区经济建设的不断发展,对于冻土的研究也引起更多学者的关注,本文主要分析了冻土力学特性,并简要介绍了冻土勘察特点。     

橡胶树PR107原生质体的分离和培养研究

以橡胶树PR107花药愈伤组织建立的胚性悬浮细胞为材料,进行原生质体的酶解分离和培养研究。结果表明：在酶组合为纤维素酶1.5 %+果胶酶0.15 %+离析酶0.5 %的酶解处理下,继代培养第6天、直径小于0.5 mm悬浮细胞团获得最高产量的原生质体,达到2.2×107个/mL PCV;原生质体在看护培养基上培养1周后观察到细胞开始发生分裂,培养2周后细胞分裂形成含8-10个细胞的小细胞团。看护培养45 d后原生质体持续分裂并发育成肉眼可见的小愈伤组织。     

虚拟关节臂式坐标测量机模型的构建与验证

关节臂式坐标测量机的测量误差受到众多因素的影响,且由物理构件带来的误差无法被消除。为此,笔者旨在构建一种虚拟关节臂式坐标测量机。首先,采用D-H矩阵建立其运动学模型,其次,利用PC-DMIS测量软件分析测量机数据并对模型的精确性进行检验,最后使用蒙特卡罗法和测量机模型完成仿真测量。通过与实际参数构建的模型、制造商参数构建的模型相对比,可知所构建测量机模型的测量精度能够满足要求。仿真结果表明提出的模型构建与验证方法对坐标测量的应用具有较高的工程价值。     

超声波辅助7S-麦芽糊精接枝反应的响应面法优化

以脱脂豆粕为原始材料,分离纯化得到β 伴大豆球蛋白（7S）。采用超声波辅助技术对7S与麦芽糊精进行接枝改性。以改性产物乳化活性（EAI）和乳化稳定性（ESI）为指标,采用Box Behnken模型对工艺条件进行优化,并对改性前后的蛋白样品进行了SDS PAGE电泳和电镜扫描（SEM）分析测定,验证7S与麦芽糊精发生糖基化反应。结果表明优化后得到的最佳改性条件为：麦芽糊精添加量9.5％,超声波处理时间30min,超声波处理功率450W ,在此条件下平均乳化活性为1.142,平均乳化稳定性为27.13min,相对天然未改性7S球蛋白分别提高了60.59%和57.06%。     

多维饮水抗运输应激对鸽血液皮质酮和生化指标的影响

为探究长途运输对鸽子造成应激的程度,评价多维饮水缓解鸽子运输应激的作用,本试验选取成年欧洲肉鸽40对随机分为两组,试验组运输前48 h开始饮用多维,对照组不采取任何措施直接运输,装笼前和经过2 h运输后,两组分别采集血液,测定相关指标.测定显示,运输后,试验组和对照组皮质酮(CORT)、肌酸激酶(CK)、葡萄糖(Glu)三个指标极显著上升(P<0.01),谷酰胺转肽酶(GGT)显著下降(P<0.05);谷草转氨酶(AST)、谷丙转氨酶(ALT)活性对照组显著提高(P<0.05),而试验组没有差异(P>0.05);白蛋白(ALB)、尿酸(UA)、高密度脂蛋白(HDL)水平对照组没有明面差异(P>0.05),试验组明显上升(P<0.05);总蛋白(TP)、低密度脂蛋白(LDL)、总胆固醇(CHO)试验组和对照组都没有产生明显差异(P>0.05).试验组运输后总蛋白(TP)浓度显著大于对照组运输后总蛋白(TP)浓度(P<0.05).结果提示,运输对鸽子的应激主要表现在心肌、肝脏的损伤,运输前通过饮用多维可有效缓解应激.     

三棱碘泡虫 (粘体动物门：碘泡科) 重描述及其系统发育关系分析

为有效鉴定三棱碘泡虫的有效性,补充其生物学特征,实验利用现代粘孢子虫整合分类学方法,包括形态特征、寄生特性(宿主特征和寄生部位)及分子特征,对其进行重新描述,证实其分类有效性,探讨其系统发育关系。结果显示,三棱碘泡虫专性寄生于草鱼鳃丝间,未在其他器官(肝脏、肾脏、肠道等)检获孢子。包囊呈乳白色,长椭圆形,长(2.4±0.3)(2.1～2.7) mm,宽(0.8±0.1)(0.6～0.9) mm。成熟孢子壳面观呈卵圆形,孢子后端未见"V"形褶皱,孢子外包裹有一层透明的圆形黏液膜,缝面观呈纺锤形,孢子缝面可见三条平行而突出的脊线;孢质均匀,孢子后端具有一个大嗜碘泡;成熟孢子长(10.3±0.4)(9.4～11.0)μm,宽(9.5±0.5)(8.7～10.9)μm,厚(7.4±0.5)(6.4～8.0)μm;两极囊等大,梨形,极丝7～8圈;组织病理显示,病灶鳃组织未出现严重炎症反应。BLAST比对发现,三棱碘泡虫与隐杆碘泡虫小核糖体RNA序列相似性最高(89.58%),但远低于种内序列相似性。分子系统发育分析结果显示,三棱碘泡虫先与寄生于鲤科鱼类的隐杆碘泡虫形成姊妹关系,再与寄生于胭脂鱼科鱼类鳃的诺布尔碘泡虫、微小碘泡虫及毕斯塔斯碘泡虫形成独立的鳃寄生碘泡虫分枝,表明宿主亲缘关系与组织趋向性在鱼类组织寄生碘泡科粘孢子虫系统演化历程中扮演重要作用。本研究补充了三棱碘泡虫包囊形态结构、组织趋向性及分子数据,证实了其分类有效性。     

Enhanced immune responses and effectiveness of refined outer membrane protein vaccines against Vibrio harveyi in orange‐spotted grouper (Epinephelus coioides)

Vibriosis is a severe infection occurring in many commercially important marine fish species. In this study, vaccines containing Vibrio harveyi recombinant outer membrane protein K (rOmpK), outer membrane protein U (rOmpU) and rOmpK‐OmpU fusion protein in addition to the metabolizable Montanide^TM ISA 763 A VG adjuvant were developed and evaluated in the orange‐spotted grouper. The results indicate that recombinant V. harveyi protein‐based vaccines resulted in a remarkably higher expression of IL‐1β and IL‐8 at 24 hr, and greater antibody production, as early as 2 weeks postimmunization. Notably, enhanced immune responses and significant protective efficacy against V. harveyi infections were observed in the fusion protein vaccine‐injected fishes with relative per cent survival value of 81.8%. Additionally, the rOmpK‐OmpU antisera presented a high bactericidal effect on not only V. harveyi, but also Vibrio parahaermolyticus and Vibrio alginolyticus. Our results demonstrated that the fusion protein rOmpK‐OmpU was an effective vaccine candidate that exhibited potentially great versatility for controlling vibrio infections.     

Investigations on zinc bioavailability of different sources and dietary zinc requirement in juvenile grouper Epinephelus coioides

An experiment was implemented to study the effect of dietary zinc levels from three zinc sources on growth performance, immunity, and tissue mineral elements deposition on juvenile grouper. Based on the zinc free feeds, dietary zinc levels of 0, 10, 20, 40, 80, and 160 mg/kg were added from zinc sulphate (ZnSO₄), tetrabasic zinc chloride (TBZC), and 2‐hydroxy‐4‐(methylthio) butyrate zinc (Zn‐HMB). The results of the 8‐week study indicated that the weight gain rate (WGR) and specific growth rate (SGR) at level 10 mg/kg were significantly higher than the control fed and the reached a plateau until level 80 mg/kg, when the sources were ZnSO₄ and Zn‐HMB. WGR and SGR decreased significantly at level 160 mg/kg compared to 80 mg/kg in group TBZC. Feed coefficient (FCR) of all zinc source groups showed trend of decrease before rising. The alkaline phosphatase (AKP) in serum, catalase (CAT), total superoxide dismutase (SOD), copper‐zinc superoxide dismutase (Cu‐Zn SOD) in liver and zinc concentrations in whole body and vertebrae increased significantly than those in control group and then kept steadily in all treatments. Regardless of the sources, the manganic content of whole body or vertebra showed a downtrend. Based on the WGR, the dietary zinc requirements in juvenile grouper were 52.94 mg/kg from ZnSO₄. The average relative bioavailability (RBV) of TBZC and Zn‐HMB was 169.33% and 200.33%, respectively, compared to ZnSO₄.