SO2和酒精处理对葡萄酒自然发酵酵母菌群的影响

【目的】研究SO2和酒精处理对葡萄酒自然发酵醪液中酵母菌群数量和种类的影响。【方法】分别对葡萄酒自然发酵醪液进行60,80,100 mg/L SO2处理和体积分数5%,10%,15%酒精处理,并分离不同发酵时期葡萄醪液中的酵母菌。应用5.8S-ITS扩增片段的RFLP分析检测技术,结合WL营养琼脂培养基上的菌落形态及颜色,对分离的酵母菌进行鉴定。【结果】无论是SO2处理还是酒精处理,发酵后期优势菌群主要为酿酒酵母;SO2处理主要对SO2敏感的酵母菌群影响较大,同时酵母菌群还受发酵产物酒精的影响,发酵中后期除酿酒酵母外只能分离到少量耐SO2的拜耳接合酵母和贝酵母;酒精处理中,发酵初期主要分离到的是克勒克酵母和假丝酵母菌株,发酵中期分离到的主要是酿酒酵母、隐球酵母和毕赤氏酵母,发酵后期以酿酒酵母为优势菌群。【结论】无论是SO2处理还是酒精处理,启动发酵的主要是非酿酒酵母,维持发酵并最终将发酵进行到最后的主要是较耐SO2和酒精的酿酒酵母。     

不同玉米果穗位姿与含水率对穗柄断裂特性的影响

为解决现有摘穗机构功耗大、苞叶残留多的问题,该文以手工摘穗为研究模本,提炼出基于果穗位姿变化的穗柄受力断裂模型。以4种不同含水率的收获期玉米为试验材料,以果穗偏转角度为因素,进行了2组穗柄拉伸断裂随机区组试验。结果表明,随着果穗偏转角度增大,穗柄拉断力、断裂拉伸量及苞叶残留率会在一临界角度产生突变;当籽粒含水率分别为34.8%、30.2%、25.1%和20.3%时,该临界角度分别为50°～55°、50°～55°、45°～50°和45°～50°;穗柄偏转达到临界角度后,玉米穗柄拉断力分别降低了80%、86%、84%和80%,断裂拉伸量增加了72%、70%、93%和84%,苞叶去除率增加了41%、34%、32%和36%;结果表明,对茎秆施加拉力时对果穗施加横向载荷,使果穗发生大于临界角度的偏转,可实现低耗摘穗;分析发现,穗柄断裂行为突变的诱因是表层纤维的受力由拉应力变为弯曲正应力,导致裂纹的萌生和扩展机理发生变化。该研究可为新型摘穗机构的设计提供理论依据和数据支撑。     

桃仁四物汤联合鹿瓜多肽治疗创伤性骨折的临床观察

目的 观察桃仁四物汤联合鹿瓜多肽治疗创伤性骨折的临床效果。方法 纳入2015年8月至2017年8月于本院收治的86例创伤性骨折患者为对象,按照随机数字表法分为两组,每组43例。两组均接受常规基础治疗,在此前提下对照组予以鹿瓜多肽治疗,观察组实施桃仁四物汤+鹿瓜多肽联合疗法,以7 d为1个疗程,均持续治疗6个疗程。对比两组消肿止痛时间、骨痂出现时间、骨折愈合时间,观察中医证候疗效及治疗前后中医证候积分变化,并分析不良反应发生状况。结果 观察组消肿止痛时间、骨痂出现时间、骨折愈合时间均显著短于对照组（P<0.01）;观察组总有效率为90.7%,对照组为72.1%,差异有统计学意义（P<0.05）;治疗后中医证候积分（疼痛、肿胀、局部压痛、纵向叩击痛、瘀斑）均明显下降（P<0.01）,且观察组低于对照组（P<0.01）;两组治疗期间均未见明显不良反应。结论 桃仁四物汤与鹿瓜多肽联合治疗创伤性骨折疗效显著,骨折愈后时间短,安全性高。     

四君子汤合五味消毒饮加减预防老年髋部骨折术后切口感染临床研究

目的 观察四君子汤合五味消毒饮加减预防老年髋部骨折术后切口感染的临床疗效。方法 选取老年髋部骨折拟择期手术患者50例,按照随机数字表法分为治疗组26例与对照组24例。对照组术前、术后给予五水头孢唑林钠预防性治疗1次,治疗组术后预防性抗生素治疗同对照组,同时术后加服四君子汤合五味消毒饮加减。观察比较两组术后切口感染发生率、第1、3、7、14 天白细胞总数、超敏C反应蛋白、体温等指标,以评估预防术后切口感染疗效。结果 术后切口感染率分别为治疗组0%,对照组16.7%,两组感染率比较差异有统计学意义（P<0.01）;治疗组白细胞总数、C反应蛋白、体温在术后第1、3、7天均低于对照组（P<0.05）,术后第14天两组比较,差异无统计学意义（P>0.05）。结论 四君子汤合五味消毒饮加减预防老年髋部骨折术后切口感染疗效显著,值得临床推广。     

Chinese wheat mosaic virus: A long-term threat to wheat in China

In China, a soil-borne virus causing a disease of winter wheat and associated with Polymyxa graminis, has been reported for many years and is now recognized as a new species, Chinese wheat mosaic virus (CWMV). Since the determination of its genomic sequence, more progress has been made in understanding its genomic structure and functions. Molecular and serological methods have been developed to help survey the distribution of the virus and to provide the basic information needed for disease forecasting and control. At present, the best countermeasure is cultivation of resistant wheat varieties. In addition, development and application of some auxiliary countermeasures, such as rotation of non-host crops, delayed seed-sowing, reasonable application of nitrogen fertilizer, and treatment of imported seeds with fungicides before sowing, may be helpful for controlling the disease. The viral distribution and damage, virion properties, genome organization and spontaneous mutation, temperature sensitivity, and disease management options are here reviewed and/or discussed to help in developing more cost-effective countermeasures to control the disease in the future.     

Tensile fracture properties of seven tropical grasses at different phenological stages

The intake of forage grasses by grazing ruminants is closely related to the mechanical fracture properties of grasses. The relationship between the tensile fracture properties of grasses and foraging behaviour is of particular importance in tropical reproductive swards composed of both stems and leaves. This study (i) quantified and compared the tensile fracture properties of stems and leaves of seven tropical grass species and (ii) provided insight into the underlying plant traits that explain differences in fracture properties between species. Fracture force, tensile strength, fracture energy and toughness of stems (in various phenological stages) and leaves were measured and compared among five introduced tropical grasses (Cenchrus ciliaris, Chloris gayana, Digitaria milanjiana, Megathyrsus maximus (syn. Panicum maximum), Setaria sphacelata) and two native tropical grasses (Setaria surgens and Dichanthium sericeum). Species differed significantly in fracture force and fracture energy, with stems and leaves of C. ciliaris and S. surgens requiring less force and energy to fracture and stems and leaves of M. maximus and S. sphacelata requiring more force and energy to fracture in comparison with the other species. Differences in tensile strength and toughness were less pronounced. The differences among species in fracture force and energy mainly resulted from differences in cross‐sectional area of plant parts rather than from differences in tensile strength and toughness.     

黄瓜子和生菜子提取物促进骨折愈合的试验研究

本试验主要研究黄瓜子和生菜子合用促进骨折愈合的作用及其初步机理。将蛋鸡60只,体重1.75～2.25 kg,造成右侧小腿中段横行闭合骨折模型,随机分为数目相等的高剂量组、中剂量组、低剂量组,阳性对照组和阴性对照组。试验组以不同比例的黄瓜子和生菜子提取物灌胃给药,阳性对照组以麝香接骨胶囊灌胃给药,阴性对照组以生理盐水灌胃,随后对各组进行动态观察、组织学观察、血清学观察和放射学观察。结果显示,黄瓜子和生菜子提取物中剂量组可促进全身代谢反应,提高血清碱性磷酸酶含量,加快血肿吸收机化,提高血钙、磷离子浓度,提高骨痂生成量和强度。结果表明黄瓜子和生菜子提取物可以通过提高钙、磷离子浓度,促进钙、磷向骨折断端转移而对骨折的愈合起到促进作用。     

Fracture Energy and Strain Softening ofConcrete under Seawater Environment

Both Three Points Bending (TPB) test on notched beams and Wedge Splitting Test (WST) were carried out on concrete specimens under six different conditions, under which they were totally dry, partially dry, water immersed, seawater immersed, 5% and 23.4% NaCl solution immersed, respectively. The fracture energy of each type of concrete and their strain softening curves were calculated according to the force displacement diagrams and inverse analysis method. It was indicated that with water, seawater or salt solution penetrating into concrete, the surface tension of pore liquids in concrete increased, which resulted in the decrease of the surface energy and load bearing capacity of concrete. After water immersed, the maximum bearing loads of specimens’ were reduced by 19.6% (TPB) and 14.5% (WST) compared with those of totally dry concrete. And for those of seawater immersed, 28.9% and 21.7% were reduced respectively. Furthermore, fracture energy of concrete was decreased more than 24% and fracture toughness was reduced significantly as well for concrete with high concentration salt solution, which made crack formation in concrete easier. The adverse influence of seawater on concrete materials had been investigated in detail from the aspects of surface energy, fracture energy and strain softening.     

胡萝卜小孢子胚状体和愈伤组织的诱导

选用胡萝卜7个常规品种、10个自交系、16个F1代杂交种和6个F2代材料研究基因型、植物生长调节剂、AgNO3以及低温预处理（4 ℃）对花药培养的影响。在参试的39份材料中有6份材料产生小孢子胚状体,其中50071号材料出胚率最高,达到3.89%,有30份材料产生小孢子愈伤组织,其中600Q6号材料出愈率达到36.70%。在B5培养基上添加2,4-D和NAA组合中,选用的4份参试材料均产生小孢子愈伤组织,其中50071和70Q67号材料产生胚状体,而添加6-BA和NAA组合中均未产生胚状体和愈伤组织。培养基中添加AgNO3对部分材料的出胚率有一定促进作用,50071和70Q67号材料在8 mg · L-1 AgNO3下出胚率分别达到10.00%和2.00%。低温预处理对部分材料的胚状体及小孢子愈伤组织形成有一定作用,50069号材料经4 ℃ 1 d预处理出胚率达1%,预处理2 d和3 d出愈率均达到11.25%,70Q67号材料在3 d预处理后出胚率达到4.00%。经细胞学鉴定,在121株由胚状体产生的再生植株中93.39%为二倍体,说明胡萝卜花药培养过程中易发生自然加倍。     

烤烟普通花叶病毒病田间自然传播能力研究

通过田间试验,研究了8类不同有效成分农药对烟草病毒病的防治效果.结果表明:8类参试药剂中除18%抑毒星和0.5%抗毒丰在烤烟生长前期对病毒病的预防有微弱效果外,其他参试药剂对烟草病毒病均未表现出预防效果,烤烟在有病原存在的情况下,施药预防与不施药预防几乎没有区别.