植物脂肪酸不饱和性对植物抗寒性影响的研究

对植物脂肪酸不饱和性与植物抗寒性关系、催化不饱和脂肪酸形成的酶特性和转化膜质脱饱和酶和酰基转移酶基因提高植物抗寒性的研究进展进行了分析论述。膜是植物低温伤害的首要发生地,细胞膜的稳定性主要决定于膜质脂肪酸不饱和性,不饱和度越高,膜稳定性越强,抗寒性越强。膜质脂肪酸不饱和度主要由膜质脱饱和酶活性和酰基转移酶的特异性不同所致,目前克隆和研究了10多个与植物细胞膜质不饱和性相关的基因,通过高效表达这些基因可以明显提高冷敏感植物的抗寒性。因此转化膜脂不饱和脂肪酸合成酶基因是提高植物抗寒性的重要途径之一。通过分析近年来的研究进展认为,今后植物脂肪酸不饱和性的研究应向农业生产应用转化,同时要加强脂肪酸脱饱和酶表达调控的研究。     

隆朋麻醉对犬红细胞免疫黏附性及红细胞膜流动性的影响

本试验旨在研究隆朋麻醉对犬红细胞黏附性和膜流动性的影响。试验选用健康本地犬12只,肌肉注射隆朋3.0 mg/kg,于麻醉前（即0 h对照组）、麻醉后2、8、24、72、120、168 h动态采集5 mL外周静脉血,离心分离红细胞,制取红细胞悬液并制备试验用红细胞膜,进行C3b受体花环率和免疫复合物花环率的检测及红细胞膜流动性的检测。C3b受体花环率在麻醉后2 h出现下降趋势,但与对照组相比差异不显著（P>0.05）,注射隆朋后8 h低于对照组且差异极显著（P<0.01）,此后开始恢复,到麻醉后168 h基本恢复正常,与对照值相比差异不显著（P>0.05）。而免疫复合物花环率则呈现相反的趋势,其在注射隆朋后出现先上升后下降的趋势。免疫复合物花环率在注药后2~24 h高于对照组且差异极显著（P<0.01）,72 h基本恢复,与对照组相比差异不显著（P>0.05）。使用荧光偏振法测定红细胞膜的流动性,结果表明,注射隆朋后犬红细胞膜流动性增加,但与对照组相比差异不显著（P>0.05）。隆朋麻醉对犬红细胞免疫黏附性及膜流动性皆存在影响,但对其膜流动性的影响不显著（P>0.05）。     

膜下播种机的设计及排种装置的室内性能试验

传统铺膜播种机在地膜上打孔播种容易形成板结,不利于发芽破土能力弱的作物生长。该文针对这一问题,分析了膜下播种机设计的要求,对主要工作部件排种装置的结构进行了分析并给出了结构参数,采用参数化造型软件Pro_E设计该膜下播种机。参照铺膜播种机试验方法,对玉米播种就机器前进速度和取种器个数进行了单因素试验。试验结果表明：当排种筒转速高于72 r/min时,空穴率明显增加;根据相关参数,推出排种筒的最佳转速为57 r/min;对于播种大株距作物,作业速度可加快;播种小株距作物,作业速度应放慢。     

紫花苜蓿不同品种对干旱胁迫的生理响应

以国内外20个优良紫花苜蓿品种为材料,研究了离体条件下叶片相对含水量、膜相对透性、游离脯氨酸和叶绿素含量等生理性状对干旱胁迫的响应,探讨了各种生理变化与抗旱性的关系,并结合草产量对其抗旱性进行了综合评价。结果表明,抗旱性强的品种在干旱胁迫下草产量高,叶片保水能力强,叶绿素持有率高,游离脯氨酸维持积累时间较长,维持积累量较高,能保持较高的细胞膜相对完整性。依据上述5项指标,通过系统聚类分析,将20个紫花苜蓿品种分为抗旱性强、较强、中等、较弱和弱5个等级。     

Amniotic membrane transplantation for corneal surface reconstruction after excision of corneolimbal squamous cell carcinomas in nine horses

OBJECTIVE: The purpose of this study was to evaluate the usefulness and effectiveness of permanent amniotic membrane transplantation as an adjunctive treatment to superficial keratectomy alone or combined with strontium-90 irradiation for treatment of equine corneolimbal squamous cell carcinoma (SCC) to decrease corneal scarring and recurrence rate. STUDY: The retrospective case study included 11 horses (n = 12 eyes) diagnosed and treated for ocular SCC that involved the limbus and cornea. Nine of those horses (n = 9 eyes) were treated between 2002 and 2006, with superficial lamellar keratectomy alone or combined with strontium-90 irradiation and followed by placement of a permanent amniotic membrane graft in the surgical defect. The level of scarring (i.e. the clarity of the cornea) resulting with the use of amniotic membrane was subjectively compared to cases where a permanent bulbar conjunctival graft was performed following keratectomy combined with strontium-90 irradiation or cryotherapy (n = 3 eyes). Recurrence was defined as the postoperative and postirradiation regrowth of SCC in the same site and globe. RESULTS: The nine horses that received an amniotic membrane graft after keratectomy alone or combined with irradiation showed a minimal level of scarring in a cornea that regained a greater transparency in comparison to the horses that were treated with a bulbar conjunctival graft. All of the horses that received an amniotic membrane graft had 226 +/- 218 days of follow-up without tumor recurrence (mean +/- SD), ranging from 21 days to 778 days. CONCLUSIONS: The combination of superficial keratectomy alone or associated with beta-irradiation and permanent amniotic membrane transplantation is an effective treatment of corneal or corneolimbal SCC in horses. The placement of an amniotic membrane material represents an alternative surgical procedure to bulbar conjunctival grafts, especially if there is a lack of bulbar conjunctiva tissue available after tumor resection or if a particularly large corneal resection is necessary. The amniotic membrane is incorporated into the corneal defect and seems to create noticeably much less scarring than a corneal defect covered by bulbar conjunctiva.     

光环境对柑桔果实品质及成熟期的影响

研究了光环境对柑桔果实品质及成熟期的影响。结果表明:柑桔园铺设反光膜能大幅提高近地面光照强度,提高果实含糖量,适当提前成熟。     

不同作物光合蛋白复合物的提取及比较分析

以双子叶C₃光合模式植物拟南芥和本氏烟草、单子叶C₃光合模式作物水稻和C₄光合玉米、双子叶C₄光合白花菜、C₃-C₄光合中间型Moricandia suffruticosa（MS）二倍体物种以及多倍体C₃作物油菜、大豆和花生为材料,运用蓝绿温和胶[Blue Native (BN)-PAGE]技术手段,在生化分子水平对C₃与C₄型、单子叶与双子叶、二倍体与多倍体不同作物光合复合物的差异进行解析。首先以拟南芥为材料优化BN-PAGE体系,证明在膜蛋白非离子型去垢剂十二烷基-β-D-麦芽糖苷（n-Dodecyl-β-D-Maltopyranoside,DM）终浓度为1%、处理时间为10min时增溶效果最好。然后用优化后的体系比较不同作物种间光合/类囊体膜复合物的差异。结果表明,光合复合物及其相应代表性亚基在蛋白丰度和组成形式等方面显著不同。与C₃、双子叶和二倍体植物相比,C₄、单子叶和多倍体作物中光系统II（PSII）核心蛋白D1在复合物中的含量升高;水稻中Cyt b₆f含量最高,不同作物之间Cyt b₆f核心亚基Cyt f丰度差异较大;玉米中光系统I（PSI）核心亚基PsaA的含量显著高于其他8种作物,且C₄作物高于C₃作物;单子叶植物中ATP酶复合物核心亚基CF1β含量显著高于双子叶植物。本研究比较了不同植物间光合蛋白复合物差异,为改良作物的光合性状和提高光合效率提供参考。     

基于AMESim的4MKJ地膜回收联合作业机开式液压系统设计与试验

为保证4MKJ地膜回收联合作业机成捆率要求,解决膜堆易散问题,提升机具自动化程度,设计4MKJ地膜回收联合作业机开式液压系统.综合考虑作业规范和田间情况拟定油缸动作方案,设计绘制开式液压系统原理图,执行机构包括4组对称安装在机具两侧的油缸,通过打捆装置调节油缸的伸缩来柔性补偿无芯膜捆的扩张量,并对液压泵和油缸进行计算和...     

不同孔径陶瓷微滤膜对石榴汁除菌效果的影响

以新疆和田酸石榴为原料加工石榴汁,采用不同孔径的陶瓷微滤膜对石榴汁进行除菌过滤,对比不同孔径(0.10、0.22、0.45μm)微滤膜的膜通量、石榴汁除菌率、营养成分含量及色值等指标的变化,确定适于石榴汁过滤除菌的陶瓷微滤膜的孔径与最佳工艺参数。结果表明,用于石榴汁过滤除菌的陶瓷微滤膜的适宜孔径为0.22μm;最佳工艺参数为:过滤压力0.20 MPa,料液温度20℃。在此条件下,陶瓷微滤膜过滤的石榴汁可保持较高的膜通量,有效去除果汁中的悬浮物和有害微生物,较好地保留营养成分,石榴汁在120 d储藏过程中的色泽变化轻微。陶瓷微滤膜过滤除菌可以作为一种除菌工艺代替石榴汁加工中的传统热杀菌工艺。     

Pilot Investigation of Water Production by Ultrafiltration Process during High Algal Period

On account of the characteristics of water in Taihu during high algal period, the pilot investigation was conducted with the combination of ultrafiltration membrane with coagulation, pre oxidation technology or adsorption technology. The results show that the quality of influent water from the three combination processes: coagulation precipitation ultrafiltration membrane, potassium permanganate coagulation precipitation ultrafiltration membrane, potassium permanganate coagulation precipitation power activated carbon ultrafiltration membrane are preferred, with turbidity lower than 0.1 NTU, algae control in the number of 2.5 × 104/L, and other measured targets meet the drinking water standards (GB 5749—2006). The organic matter of high algal water mainly includes hydrophobic organic compounds which are major factors leading to membrane fouling. The effective pre treatment before ultrafiltration membrane can prevent hydrophobic organic compounding into the membrane pore, which will effectively ease the membrane fouling during the high algal period.