金丝桃素粉剂对人工感染传染性囊病病毒鸡的疗效试验

金丝桃素是从贯叶连翘中提取的一种极具抗病毒活性成分。为了研究金丝桃素粉剂对腔上囊的治疗效果,对20日龄雏鸡人工感染传染性囊病病毒(IBDV BC-6/85)后,以不同的剂量连续4d口服金丝桃素粉剂。通过观察腔上囊和肌肉的出血情况,以及病原分离,评价该药物对鸡传染性囊病的治疗效果。结果表明:以667.9mg/kg体重的金丝桃素粉剂连续口服给药4d,能有效的治疗传染性囊病,效果优于对照药物高免卵黄抗体。     

番茄集约化穴盘育苗技术

番茄是育苗移栽主要蔬菜种类之一，据国家大宗蔬菜产业技术体系不完全统计，全国番茄集约化穴盘育苗的种植率已达30% 以上。笔者根据以往研究进展，综合品种选择、设施消毒、穴盘选型、基质配制、播种方法、环境管理、水肥供给、适应性驯化、成苗标准等，汇集成番茄集约化穴盘育苗技术要点，旨在为番茄集约化穴盘育苗技术的规范化和快速推广应用提供参考。     

半干旱地区春小麦有限补灌节水增产技术研究

利用汇集雨水对春小麦进行补灌方式、补灌时期及补灌量的试验表明,不论贫水年和丰水年,有限滴灌均能明显使作物节水增产。膜下滴灌方式的保墒节水效应和提高水分利用效率作用明显;春小麦的拔节一孕穗期是实施补灌的关键时期;春小麦全生育期滴灌补灌定额900m^3/hm^2,重点应加强促苗水、拔节水、孕穗水和灌浆水。     

5个重庆地方猪种遗传多样性的微卫星分析

目的通过微卫星标记评估8个安徽地方猪品种的遗传多样性。方法采用PCR和聚丙烯酰胺凝胶电泳对FAO-ISAG联合推荐的15个微卫星标记进行分型,并计算有效等位基因数 (N_e)、期望杂合度 (H_e)、多态信息含量 (PIC)、F统计量和遗传距离等参数,探讨品种间的遗传多样性和遗传关系。结果15个微卫星标记共检测到272个等位基因,平均有效等位基因数9.561 2个。8个品种的有效等位基因数在2.445 1~3.786 6之间,期望杂合度在0.532 0~0.714 8之间,多态信息含量在0.369 8~0.890 6之间。F统计量和基因流 (N_m) 分析表明：安徽地方猪品种间存在一定程度的近交和基因流动。基于Nei氏遗传距离 (D_s) 构建系统发生树显示：8个地方猪种可分为两类：一类为皖南花猪;另一类又聚为两小支,一小支为安庆六白猪、圩猪和霍寿黑猪,另一小支为皖北猪、皖南黑猪、枞阳黑猪和定远猪。结论8个安徽地方猪种遗传多样性丰富,群体内存在一定程度的近交和基因流动。结果为安徽地方猪种的保护和利用提供了理论依据。     

基于有限元分析方法的连杆螺栓改进设计

根据生产企业的实际情况,提出了在应力集中严重的连杆螺栓头部与杆部过渡圆弧处进行局部滚压的改进措施,并通过有限元分析手段,得出当滚压力达到20kN时,就能使连杆螺栓在不改变原结构的前提下满足疲劳寿命的要求。     

In vitro differentiation of exocrine pancreatic cells from mouse embryonic stem cells

AIM: To explore the effects of sodium butyrate, activin A and dexamthasone on inducing mouse embryonic stem (ES) cells to differentiate into exocrine pancreatic cells in vitro. METHODS: E14 mouse ES cells were cultured in suspension to form embryonic bodies (EBs). The EBs were cultured with differentiating medium containing different concentrations of sodium butyrate, and the spontaneously differentiated ES cells were used as control. Exocrine pancreatic genes such as amylase, chymotrypsinogen, elastase 1, elastase 2 and carboxypeptidase were detected by RT-PCR at different time points to determine the optimal concentration and exposure time of sodium butyrate. Furthermore, activin A or dexamthasone was also used to explore the effects on exocrine differentiation. After that, the combination of sodium butyrate, activin A and dexamthasone was used to promote the differentiation of exocrine pancreatic cells from ES cells. During the differentiation course, the gene expressions of amylase, chymotrypsinogen, elastase 1, elastase 2 and carboxypeptidase were detected by RT-PCR. Morphological changes were investigated by phase contrast microscopy. Amylase expression was examined by immunofluorescence staining. RESULTS: Exocrine pancreatic gene expressions such as amylase, chymotrypsinogen, elastase 1, elastase 2 and carboxypeptidase were detected in spontaneously differentiated EBs. A relatively lower concentration of sodium butyrate with a shorter exposure time significantly promoted those above gene expressions as compared to that of spontaneously differentiated EBs. Activin A and dexamethasone induced upregulation of exocrine gene expression. The combination of activin A, sodium butyrate and dexamethasone significantly enhanced the mRNA levels of amylase, chymotrypsinogen, elastase 1, elastase 2 and carboxypeptidase. Under the treatment of activin A, sodium butyrate and dexamethasone, differentiated cells were polygonal in shape with large, round, and center-situated nuclei. According to the observation of immunofluorescence staining, amylase was positive expressed at the final stage. CONCLUSION: These data indicate that exocrine pancreatic differentiation of ES cells is induced by sodium butyrate, activin A and dexamethasone. The combination of pancreatic inducing factors improves the differentiating efficiency.     

光子棉花的产量杂种优势研究

利用综合性状较好的5个光子材料作亲本,与17个优良毛子棉花新品种(系)组配19个光子杂交组合,研究具有光子标记性状杂交组合的产量杂种优势表现.结果表明:光子杂交组合皮棉产量表现正向中亲优势和正向超亲优势,籽棉产量光子作母本的杂交组合杂种优势高于光子作父本的杂交组合;衣分和单铃重表现正向中亲优势,单株铃数光子作母本的杂交组合优势率高于作光子父本的杂交组合;籽指表现负向中亲优势、负向超亲优势和负向竞争优势,筛选出产量竞争优势5%以上、综合性状突出的优势组合8个.     

Synthesis and Antibacterial Activity of Dihydrocumatacylthiourea

以β-蒎烯为原料、碱性高锰酸钾为氧化剂合成了诺蒎酸,诺蒎酸酸性脱水并异构开环得到二氢枯茗酸.二氢枯茗酸经过酰氯化、酯化,再与相应的胺反应得到了6种酰基硫脲化合物,通过IR,1H NMR,MS和元素分析对产物进行了结构鉴定,并通过抑菌环法对化合物的抑菌活性进行了测试.测试结果表明,化合物二氢枯茗邻甲苯酰基硫脲(Ⅵc),二氧枯茗间甲苯酰基硫脲(Ⅵd)对大肠杆菌的抑菌圈直径分别是11.33、11.00 mm,高于市售试剂新洁尔灭.     

香榧和山核桃中铅含量水平及富集原因分析

在浙江香榧和山核桃生产基地、超市和农贸市场实地抽样检测,对数据进行统计分析,研究浙江省香榧和山核桃中铅含量水平。香榧有效样本数158个,铅含量平均值0．113mg／kg,符合NY5324--2006（（无公害食品常绿果树坚果》标准要求（铅≤0．2mg／kg）,含量范No．034～0．382mg／kg;山核桃有效样本数216个,铅含量平均值0．211mg／kg,符合NY5307--2005《无公害食品落叶果树坚果》标准要求（铅≤0．4mg／kg）,含量范围0．013—0．409mg／kg。     

中国野生葡萄抗霜霉病相关基因VpPR4b及其启动子的克隆和功能分析

以中国野生葡萄(Vitis piasezkii)‘留坝–8’(抗霜霉病)和欧亚种葡萄(V. vinifera)‘黑比诺’(易感霜霉病)为材料,克隆得到抗霜霉病相关基因VpPR4b和VvPR4b。序列分析发现VpPR4b和VvPR4b核苷酸序列相似性为98.61%。VpPR4b编码区为432 bp,编码143个氨基酸,含有BARWIN保守结构域,属于典型的Ⅱ型PR4蛋白。VpPR4b和VvPR4b均可在霜霉菌侵染后诱导表达。亚细胞定位表明VpPR4b定位于细胞膜上。分别从‘留坝–8’和‘黑比诺’中克隆得到了VpPR4b和VvPR4b的启动子,其序列相似性高达95.65%,并且含有相似的顺式作用元件。通过酵母单杂交验证了转录因子WRKY40和WRKY75可以结合VpPR4b启动子。本研究的结果表明PR4b可能在葡萄抵御霜霉病侵染过程中发挥一定作用。