潜伏期马立克氏病病鸡血清型病毒L-meq、meq基因的比较及遗传分析

从潜伏期感染马立克氏病病毒(MDV)鸡淋巴组织中提取基因组DNA,采用梯度PCR的方法获得MDV的L-meq、meq基因,将其插入pMD18-T克隆载体,经测序并进行了序列分析。结果表明,L-meq、meq基因同源性很高,L-meq中只有180bp与meq不同。但是采用同样的方法在发病期病鸡淋巴组织中却只能获得MDV的meq基因。为了进一步研究发病期L-meq基因消失的原因,试验对L-meq、meq基因的氨基酸序列的结构域进行了分析。结果表明,L-meq基因中含有9个PRR(proline-rich-reapts)区域,meq中含有6个PRR区域,从而推断PRR区域可能与基因的转录激活及调控病毒DNA复制的功能有关,该180bp插入序列也许能解释初期感染MDV不致瘤的原因,同时也意味着L-meq基因对于潜伏期的维持是必要的。     

不同年龄高原牦牛肺脏的组织结构特征

为了研究牦牛肺脏对高原低氧的适应性过程的结构基础,通过多种组织化学方法和透射电镜技术对1日龄、5月龄和成年牦牛肺脏显微结构和超微结构进行研究。研究发现：1日龄、5月龄和成年组牦牛肺动脉中膜肌层所占管径的比例（MT%）均较高,分别为10.71%、12.53%和11.18%;1日龄牦牛细支气管管壁已形成一层完整的平滑肌层。牦牛呼吸道杯状细胞的分泌颗粒电子密度高,在颗粒中心有低电子密度的区域;Clara细胞的分泌物是有膜包裹的致密分泌颗粒、少量致密分泌颗粒和灰白色物质混合的分泌滴。1日龄、5月龄牦牛肺动脉受低氧的影响较大,内皮细胞增殖明显,呈立方状,突入管腔呈栅状排列;平滑肌细胞肥大呈立方状、细胞器显著增多;各年龄组牦牛血-气屏障厚度均很薄,与低海拔地区大鼠接近,1日龄、5月龄和成年组厚度分别为0.445、0.506和0.423μm。以上结果表明,低氧对肺动脉内皮细胞、平滑肌细胞和细支气管平滑肌有明显的影响,这种影响在5月龄牦牛表现最为显著,但随着年龄的增长,低氧对牦牛肺脏结构的影响逐渐减弱。这种结构与年龄相关的变化表明牦牛在生长发育过程中其肺脏逐渐适应了高原低氧的环境。     

长沙市区马尾松人工林生态系统碳储量及其空间分布

\t\t\t\t\t目的\t\t\t\t\t通过对帽儿山不同红松人工林凋落物的分析测定,研究不同红松人工林凋落物含量、组成以及凋落物碳密度的动态规律和特点,为其区域尺度上森林碳储量的估测和碳汇林业的开展提供科学和理论依据。\t\t\t\t\t\t\t\t\t\t\t\t\t方法\t\t\t\t\t运用凋落物筐收集法对帽儿山地区红松人工纯林、白桦—红松人工混交林和蒙古栎—红松人工混交林的凋落物进行研究。\t\t\t\t\t\t\t\t\t\t\t\t\t结果\t\t\t\t\t不同林型凋落物组成不同,凋落物含量和凋落物碳密度随着林龄的增长也逐渐增加,3种林型42年林龄凋落物含量和碳密度均明显大于20年;不同林型的人工林凋落物碳密度差异显著,20年人工林凋落物碳密度表现为：白桦—红松林 [0.751 t/(hm²·a)] >蒙古栎—红松林 [0.721 t/(hm ²·a)] >红松纯林 [0.688 t/(hm ²·a)](P<0.05);42年生人工林凋落物碳密度依次为：蒙古栎—红松林 [2.995 t/(hm²·a)] >白桦—红松林 [2.779 t/(hm ²·a)] >红松纯林 [2.007 t/(hm ²·a)](P<0.05)。\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t结论\t\t\t\t\t不同林型的红松人工林凋落物碳密度差异显著,混交林明显大于纯林;林分凋落物碳密度随着林龄的增长而增加。\t\t\t\t     

Effects of atorvastatin on cardiac myocyte hypertrophy of neonatal rat induced by angiotensinⅡ in vitro and TLR4 expression

AIM: To assess effects of atorvastatin (Ator) on cardiac myocytes (CM) hypertrophy of neonatal rat induced by angiotensinⅡ (AngⅡ) in vitro and Toll like receptor 4 (TLR4) expression for theoretical bases of preventing and treating myocardial hypertrophy.METHODS: CM of neonatal Sprague-Dawley (SD) rats were isolated with trypsin digestion method and those growth-arrested cells were stimulated with 10^-7 mol/L AngⅡ in the presence of various concentrations of Ator.The method of coomassie brilliant blue was adopted to evaluate the protein contents of CM.The changes in β-MHC,AT₁ receptor and TLR4 mRNA expression were observed by RT-PCR.RESULTS: ① AngⅡ increased the protein content of CM and β-MHC mRNA expression significantly,upregulated AT₁ receptor and TLR4 gene expression.② In a dose-dependent manner,Ator inhibited the increases in the protein contents of CM and β-MHC mRNA expression induced by AngⅡ.③ In a dose-dependent manner,Ator downregulated the AT₁ receptor and TLR4 mRNA expression of CM hypertrophy of neonatal rat induced by AngⅡ.CONCLUSION: Ator inhibits CM hypertrophy,downregulates the AT₁ receptor and TLR4 gene expression.     

我国草地贪夜蛾应急化学防控风险评估及对策

草地贪夜蛾Spodoptera frugiperda (J.E.Smith)是世界性重大农业迁飞害虫, 在我国已呈严重暴发态势, 对我国玉米等农作物生产安全构成严重威胁?农药防治是草地贪夜蛾应急防控中最有效的手段之一, 但是不合理的使用农药会对环境安全和施药人员带来潜在的风险?本文结合我国田间化学农药防治草地贪夜蛾的实践和效果, 评估了8种田间常用防治药剂的环境风险及其对施药人员的健康风险?推荐甲氨基阿维菌素苯甲酸盐?乙基多杀菌素?氯虫苯甲酰胺?虱螨脲作为草地贪夜蛾应急防控的首推农药, 甘蓝夜蛾核型多角体病毒作为首推生物药剂, 高效氯氟氰菊酯和乙酰甲胺磷须谨慎使用?本研究从农药应用风险角度提出了具体的草地贪夜蛾合理用药建议, 以期为草地贪夜蛾的有效安全防控提供科学依据?     

秸秆覆盖量和覆盖时间对党参生长及光合特性的影响

试验以露地不覆盖(CK1)和地膜露头覆盖(CK2)为双对照,设置了移栽覆盖(A1)和出苗覆盖(A2)2个覆盖时间,4500 kg·hm-2(B1)、7500 kg·hm-2(B2)、10500 kg·hm-2(B3)、13500 kg·hm-2(B4)4个覆盖量,采用二因素随机区组设计,研究了秸秆覆盖量和覆盖时间对党参...     

Reversing effect of naringin on cisplatin resistance in human lung cancer A549/DDP cells

AIM: To investigate the effect of naringin (NRG) on cisplatin (DDP) resistance in human lung cancer A549/DDP cells and its possible mechanism. METHODS: A549/DDP cells were cultured in vitro and treated with NRG and/or DDP at different concentrations for 24 h, and then the cell viability were measured by CCK-8 assay. The combination index (CI) of NRG and DDP were analyzed by Chou-Talalay method. The apoptosis rate was analyzed by flow cytometry. Western blot was performed to detect the protein levels of P-glycoprotein (P-gp), multidrug resistance-associated protein 1 (MRP1), p-Akt, CXC chemokine receptor 4 (CXCR4), cleaved caspase-3, Bcl-2 and Bax.RESULTS: The protein levels of P-gp, MRP1, p-Akt and CXCR4 in the A549/DDP cells were higher than those in the A549 cells (P<0.05). The cell viability was remarkably reduced in a dose-dependent manner when A549/DDP cells were exposed to NRG and/or DDP (P<0.05), and the IC₅₀ values of NRG and DDP were 36.92 μmol/L and 129.77 μmol/L, respectively. When the inhibition rate exceeded 15%, NRG in combination with DDP produced a synergistic effect (CI<1). Combination treatment with NRG and DDP significantly induced apoptosis (P<0.05), up-regulated the protein levels of cleaved caspase-3 and Bax, and down-regulated the protein level of Bcl-2 (P<0.05). Meanwhile, NRG remarkably down-regulated the protein levels of P-gp, MRP1, p-Akt and CXCR4 in a dose-dependent manner (P<0.05). CONCLUSION: NRG may enhance the sensibility of A549/DDP cells to DDP most likely via up-regulating the protein level of Bax and down-regulating the protein levels of Bcl-2, P-gp, MRP1, p-Akt and CXCR4.     

青海省三江源地区草地土壤有机质与砷含量空间分布特征

测定了青海省三江源地区土壤有机质与砷含量,并采用普通克里格插值方法研究其空间分布特征,结果显示:三江源地区土壤有机质含量多分布于3.0%～6.0%之间,约占样本总数的68%,超过7%的样品比例约为4%;土壤砷含量主要集中在0～10mg/kg之间,约占样本总数的50%,含量超过30mg/kg的样品比例为20%。土壤有机质含量与海拔之间存在显著负相关(r=-0.346,P<0.05),线性拟合方程为y=-0.042x+4.87(R2=0.11,P<0.05);土壤砷含量与海拔、土壤有机质含量之间均没有显著相关性。土壤有机质含量的块金效应为43.98%,存在中等程度的空间自相关关系;土壤砷含量的空间相关性强,块金效应为23.94%。土壤有机质和砷含量在大尺度上都存在比较明显的空间分布特征。     

色素万寿菊组织培养培养基组成的初步研究

以色素万寿菊腋芽作为外植体材料,筛选各个阶段的培养基配方,研究色素万寿菊的组织培养技术。结果表明：MS＋BA 0.5 mg/L＋NAA 0.1 mg/L对腋芽诱导芽的效果最好;MS＋BA 1 mg/L＋NAA 0.01 mg/L为继代培养基的适宜配方;1/2MS＋IBA 0.1 mg/L生根效果很好。     

苜蓿新品系Dy-2006亲缘关系的SSR分析

应用SSR分子标记对苜蓿新品系Dy-2006等6个苜蓿品种(品系)亲缘关系进行了分析.8对SSR引物共扩增出128个位点,106个位点显多态性,多态位点比率82.81%;不同苜蓿品种(品系)SSR多态性百分率存在一定差异,在32.81%～45.31%之间.遗传相似度(F)和遗传距离(D)的变化分别范围在0.9062～0.9689和0.0326～0.0762.聚类分析结果显示,新品系Dy-2006与龙牧801亲缘关系相对较近,与阿尔冈金亲缘关系较远,并与其它供试品种存在一定差异,为一个相对独立的品系.