化学杂交剂对灌浆期小麦源流库的影响

以大穗小麦品种SN05-3和多穗小麦SN02-3为试验材料,研究了化学杂交剂BAU-9403对灌浆期小麦库、源、流的影响.结果表明,BAU-9403诱导的小麦雄性不育率大于95%,异交结实率高于92.5%;BAU-9403能够显著降低旗叶叶绿素含量和提高其净光合速率;喷药处理的干物质日生产量,茎、叶、鞘的干物质转移量及其输出率和转换率均下降;喷药处理籽粒饱满度平均减少0.222,平均灌浆速率降低0.306g/1000 grains·d-1,灌浆持续期平均缩短6.03d.BAU-9403处理的SN05-3净光合速率增加幅度、叶绿素含量及茎中干物质转移量、输出率和转换率下降幅度均高于SN02-3,而叶中干物质转移量下降幅度和鞘中的干物质输出率却低于SN02-3;SN05-3的灌浆持续期缩短幅度明显大于SN02-3,而其灌浆速率下降的程度小于SN02-3.综合分析表明,BAU-9403能够影响灌浆期小麦的光合生理特性,破坏库、源之间的平衡关系,使干物质积累和转运不畅,导致粒重下降,且品种间的反应存在差异.     

Effect of mixing on biogas production during mesophilic anaerobic digestion of screened dairy manure in a pilot plant

The effect of mixing on biogas production of a 1.5‐m³ pilot continuous stirred tank reactor (CSTR) processing screened dairy manure was evaluated. Mixing was carried out by recirculation of reactor content with a mono pump. The experiment was conducted at a controlled temperature of 37±1°C and hydraulic retention times (HRTs) of 20 and 10 days. The effect of continuous and intermittent operation of the recirculation pump on biogas production was studied. At 10 days of HRT, the results showed a minimal influence of recirculation rate on biogas production and that continuous recirculation did not improve reactor performance. At 20 days of HRT, the recirculation rate did not affect reactor performance. Combination of low solid content in feed animal slurry and long HRTs results in minimal mixing requirements for anaerobic digestion.     

颅内动脉瘤开颅术后患者肺部感染的危险因素分析

目的:探讨颅内动脉瘤开颅术后发生肺部感染的危险因素。方法:回顾性分析在我院接受开颅手术治疗的211例颅内动脉瘤患者的性别、年龄、吸烟史、糖尿病史、高血压病史、Hunt-Hess分级、动脉瘤部位、动脉瘤直径、手术时机及术后肺部感染的情况,对可能导致肺感染的因素行X2检验及Logistic回归分析。结果:单因素分析显示影响颅内动脉瘤患者术后肺感染的因素主要包括年龄、吸烟、糖尿病、Hunt-Hess分级(P0.05)。多因素Logistic回归分析结果显示影响颅内动脉瘤患者开颅术后发生肺部感染的因素为吸烟和Hunt-Hess分级。结论:吸烟、高Hunt-Hess分级是影响颅内动脉瘤开颅术后发生肺部感染的独立危险因素。     

人颗粒裂解肽片段在大肠杆菌中的表达

目的：建立颗粒裂解肽（NKG5）的原核表达载体系统,并在大肠杆菌中获得表达。方法：采用寡核苷酸合成、PCR扩增得到NKG5编码序列,克隆到pGEM-T载体上,经测序正确后,再切下编码序列连接到重组表达载体pGEx-4T-1中,转化大肠杆菌BL21,用IPTG诱导重组工程菌表达,采用谷胱甘肽偶联的Sepharose 4B纯化重组蛋白。结果：重组菌株可以表达GST-NKG5融合蛋白,用免疫印迹反应鉴定纯化的融合蛋白,在相对分子质量34000处有一条带。结论：获得了在大肠杆菌中低表达的颗粒裂解肽融合蛋白,为后续研究奠定了基础。     

中国稻弄蝶属Parnara分类与一新记录种(鳞翅目:弄蝶总科:弄蝶科)

记述中国稻弄蝶属Parnara Moore,18814种,其中圆突稻弄蝶Parnara apostata（Snellen,1866）为1新记录种。制作了分种检索表,进行了新记录种的成虫形态描述,提供了特征图。     

CO2浓度增加和施氮对栓皮栎幼苗生理生态特征的影响

通过人为控制CO₂浓度(700、400 μmol·mol^-1)和氮素水平(120 kg N·hm^-2),研究了CO₂浓度增加和氮沉降及其交互作用对北界(辽宁庄河)栓皮栎幼苗生理生态特征的影响.结果表明: CO₂浓度升高使栓皮栎幼苗叶片的形态、光合色素含量和氮含量有减小的趋势,暗呼吸速率较对照降低63.3%,可溶性糖增加2.6%.氮沉降对栓皮栎叶片的形态和光合色素含量有明显的促进作用,叶N含量增加而K含量降低,N/K值增加26.7%.CO₂和N交互作用对幼苗叶形态和光合作用有明显的促进作用,叶片最大净光合速率和光饱和点分别是对照的1.4倍和2.6倍,暗呼吸速率和光补偿点分别降低65.9%和50.0%.CO₂浓度升高和N沉降均对栓皮栎幼苗生长有一定的促进作用,可能导致栓皮栎分布界线北移.     

钙库调控的钙通道Orai1体外研究方法的建立

目的:建立钙通道Orai1的体外研究方法。方法:利用脂质体重组技术,将体外纯化的Orai1蛋白重组到脂质体膜上,利用蔗糖密度梯度离心来检测其重组效率及Orai1蛋白在脂质体膜上的结构,并利用钙染料Fura-2检测脂质体内钙离子的释放。结果:成功制备了脂质体及体外纯化了GST-Orai1融合蛋白,蔗糖密度梯度离心结果证明GST-Orai1蛋白成功重组到脂质体上,以及Orai1蛋白以多聚体的形式定位在脂质体膜上。钙离子释放实验证明脂质体内钙离子包装完好,可用于后续Orai1钙通道的功能研究。结论:利用脂质体重组技术建立了一种新的Orai1的研究方法,能够更直接有效地研究其功能及其活化机制。     

Interplay between hydrophobic cluster and loop propensity in beta-hairpin formation

Autonomously folding beta-hairpins have recently emerged as powerful tools for elucidating the origins of antiparallel beta-sheet folding preferences. Analysis of such model systems has suggested four potential sources of beta-sheet stability: (1) the conformational propensity of the loop segment that connects adjacent strands; (2) favorable contacts between side-chains on adjacent strands; (3) interstrand hydrogen bonds; and (4) the intrinsic beta-sheet propensities of the strand residues. We describe the design and analysis of a series of isomeric 20 residue peptides in which factors (1)-(4) are identical. Differences in beta-hairpin formation within this series demonstrate that these four factors, individually, are not sufficient to explain beta-sheet stability. In agreement with the prediction of a simple statistical mechanical model for beta-hairpin formation, our results show that the separation between the loop segment and an interstrand cluster of hydrophobic side-chains strongly influences beta-hairpin size and stability, with a smaller separation leading to greater stability.