小灵通无线网络的优化

小灵通无线网络优化主要是在对PHS系统的有关数据有效采集的基础上,进行网络性能分析和问题分析,从而采取相应对策达到使网络处于最佳状态运行的目的。     

长白猪肝脏、肾脏和淋巴结的显微形态及糖原PAS反应研究

[目的]对商品长白猪的组织形态学进行研究,了解商品长白猪宰前的生理状态。[方法]采集长白猪的肝脏、肾脏和淋巴结3种组织器官并制成石蜡切片,采用H.E染色方法对其组织结构进行研究。[结果]肾脏和肝脏的组织结构形态正常,肾脏和肝脏的细胞核染色明显,淋巴结的皮质和髓质分界不清晰,周围组织没有明显的淋巴索,淋巴窦较小。糖原PAS染色结果表明肝脏中的糖原颗粒较少,分布不均匀,而肾脏中糖原或糖蛋白多集中于血管球和肾小囊壁上。[结论]该研究可为今后进一步的商品长白猪理论研究奠定基础。     

氮离子束等诱变机理研究（二）

不同诱变源（Ｎ＋束、γ－ｒａｙ等）与不同小麦样品互作,经光声效应分析和染色体结构和变异的鉴定,初步证实Ｎ＋束正如γ－ｒａｙ一样可作为染色体畸变和基因重组的有效诱变源。     

内皮PAS1蛋白(EPAS1)基因的研究进展

内皮PAS1蛋白(EPAS1/HIF-2)是细胞应对缺氧时关键的转录因子,在生物体生理及病理过程中有重要作用。文中对EPAS1的结构、分布、表达调控及在病理过程中的作用、高原低氧适应性方面进行了综述,为今后进一步研究EPAS1提供了参考和借鉴。     

葡萄微茎尖培养及葡萄扇叶病毒的ELISA和探针检测

在建立‘藤稔’等５个葡萄品种离体培养快速繁殖体系的基础上，通过热处理和微茎尖脱毒培养获得了再生植株；并经过ＰＡＳ－ＥＬＩＳＡ和长臂光敏生物素标记ＧＦＬＶ－ＣＰ基因ｃＤＮＡ探针检测．结果表明白天３８℃夜晚３５℃处理脱除ＧＦＬＶ效果最佳；多次继代培养也有脱除ＧＦＬＶ的作用．从而首次获得了‘藤稔’、‘红地球’、‘９３０７’３个葡萄品种的脱除ＧＦＬＶ的试管苗．ＰＡＳ－ＥＬＩＳＡ与探针平行检测的结果还表明，ＰＡＳ－ＥＬＩＳＡ检测以Ｐ／Ｎ＜１作为阴性标准更为可靠     

一起猪弓形虫病自然病例的病理学观察

本研究对2头猪弓形虫病自然病例的病理变化进行系统地观察.结果显示病死猪均表现猪弓形虫病特征性病变,如皮肤发绀并有出血斑点,典型的间质性肺炎,伴有肝硬化的坏死性肝炎,出血性-坏死性淋巴结炎、间质性肾炎、坏死性脾炎、出血性溃疡性胃炎和出血性肠炎等.     

大鼠原代肝细胞分离培养方法的改良

本研究的目的是改进经典的Seglen原位两步胶原酶灌流法,建立稳定简便的大鼠原代肝细胞分离培养方法.采用胰酶消化获取大鼠肝细胞进行纯化、培养,过碘酸-雪夫反应(PAS)鉴定.结果显示,本法培养的肝细胞产量高、活力好,每只大鼠可获得约2×108个肝细胞;相差显微镜观察不同生长期的肝细胞,细胞贴壁后变平变薄,双核细胞呈岛状连接的形态学特性;PAS鉴定,肝细胞内由于含有大量的糖原颗粒而被染成红色.表明改良的方法稳定、高效,为进一步的试验研究奠定了基础.     

Effect of Nile tilapia, Oreochromis niloticus (L.), size on phytoplankton filtration rate

Four different‐sized (390±3, 140±2, 40±2, 16±1 g) Nile tilapia, Oreochromis niloticus (L.), stocked at the same biomass in timed pulse feeding chambers were provided 27–29°C water dominated by Microcystis (82%) and Scenedesmus (18%) to determine the effect of fish size on filtration rates. The number of Microcystis and Scenedesmus units filtered from the water decreased significantly with increasing tilapia size. The shaping constants and maximum filtration rates for Ivlev's feeding model used to describe the relation between filtration rates and the suspended particulate organic carbon (POC) concentrations were significantly different among the four sizes. Filtration rates of 763, 671, 512 and 300 mg C kg^?1 h^?1, which correspond to 70%, 82%, 86% and 90% saturation levels, were achieved at POC levels of 30, 32, 32 and 33 mg C L^?1 for 16, 40, 140 and 390 g Nile tilapia respectively. Smaller tilapia achieved these rates at lower POC concentrations than larger tilapia.     

猪附红细胞体ORF2的全基因合成、表达与鉴定

通过重叠区扩增法（PCR-based accurate synthesis,PAS）人工合成猪附红细胞体ORF2基因,并使其在大肠杆菌（DE3）中高效表达。根据GenBank注册的AJ504999的ORF2基因序列,选择大肠杆菌偏爱的密码子,设计并合成11对寡核苷酸片段,用PAS方法,人工合成ORF2基因。基因克隆入pMD18-T载体,经测序证实正确后,连接到表达载体PET-28a,获得重组表达质粒PET-28a/ORF2,导入大肠杆菌BL21（DE3）,在37℃,IPTG终浓度1mmol/L的条件下诱导表达,经SDS-PAGE分析,Western-blot鉴定,在35 000附近出现目的片段。同时通过生物信息学软件对其蛋白二级结构及抗原表位等方面进行预测。     

A comparative study of the Barley yellow dwarf virus species PAV and PAS: distribution,accumulation and host resistance

This study investigated the distribution and characteristics of the Barley yellow dwarf virus (BYDV) species BYDV‐PAS, which was recently separated from BYDV‐PAV, the most commonly studied BYDV species. Throughout 3 years of experimental monitoring of BYDV incidence, PAS was the most frequently occurring species infecting cereals and grasses in the Czech Republic. Furthermore, Rhopalosiphum maidis and Metopolophium dirhodum were recorded as BYDV‐PAS vectors, even though M. dirhodum does not usually transmit BYDV‐PAV. In field experiments with barley and wheat, where virus accumulation, symptoms and effect on the yield were tested, BYDV‐PAV was more severe than PAS. Infection with the BYDV‐PAV isolate resulted in greater expression of symptoms and also in a greater reduction in plant height and grain weight per spike than BYDV‐PAS. In a sensitive cultivar of barley (Graciosa), the amount of viral RNA of BYDV‐PAV was also significantly higher than that of BYDV‐PAS. In a tolerant line (Wbon‐123), however, no such differences were found. In conclusion, although BYDV‐PAS seems to be dominant in the Czech Republic, BYDV‐PAV has the potential to cause more significant crop losses in barley and wheat.