影响小麦高产的主要因素及对策

沈丘县是农业大县,农作物以小麦为主,近年来,随着耕作方式、施肥方法、施肥量和管理水平的变化,小麦高产遇到瓶颈,通过分析沈丘县小麦生产现状,探索小麦在高产、优质方面再上新台阶的方法和途径。     

一例猫犬小孢子菌感染的诊治

本文通过一例猫犬小孢子菌感染的诊治,去探究可应用于临床的治疗方案。改善临床上治疗猫犬小孢子菌感染周期长,治疗效果不明显等问题。并对相关防治与人畜共患病问题进行讨论。     

Bacterial communities associated with natural and commercially grown rooibos (Aspalathus linearis)

Aspalathus linearis is a commercially important plant species endemic to the Cape Floristic Region of South Africa and is used to produce a herbal tea known as rooibos tea. Symbiotic interactions between A. linearis and soil bacteria play an important role in the survival of Aspalathus plants in the highly nutrient-poor, acidic fynbos soil. The aim of this study was to characterize and compare rhizosphere and bulk soil bacterial communities associated with natural and commercially grown A. linearis, as well as the effect of seasonal changes on these communities. Bacterial communities were characterized using high throughput amplicon sequencing, and their correlations with soil chemical properties were investigated. The N-fixing bacterial community was characterized using terminal restriction fragment length polymorphism and real time quantitative polymerase chain reaction. Actinobacteria, Proteobacteria, and Acidobacteria were the most dominant bacterial phyla detected in this study. Highly similar bacterial communities were associated with natural and commercially grown plants. Significant differences in the bacterial community were observed between rhizosphere and bulk soils collected in the dry season, while no significant differences were detected in the wet season. This study provides insights into bacterial community structure and potential factors shaping bacterial community structure with commercially important A. linearis.     

猪繁殖与呼吸综合征的概述

正猪繁殖与呼吸综合征(PRRS)首次报道是1987年在美国。从那时起,PRRS疫情和病毒的成功分离已在整个北美和欧洲被发现或证实。1病因及流行病学病原体是组动脉炎的病毒。该病毒有包膜,个体大小从45至80 mm。病毒经乙醚或氯仿处理后可能会灭活;然而,该病毒在冷冻条件下极其稳定,在-70℃下其感染性能保持4个月,随着温度的升高,感染性降低(56℃下15~20 min)。     

体重决定猪回肠内的蛋白吸收率

<正>近期伊利诺伊大学的J.A.Almeida博士、 Hans H.Stein博士以及Carsten Pedersen博士联手展开体重对于标准化回肠蛋白质和氨基酸吸收率的影响试验,结论证明,20 kg以下的仔猪回肠对于粗蛋白和氨基酸的吸收率比20~50 kg的育成猪和50~110 kg的育肥猪低。而且同一猪群的不同猪只也表现出吸收率的差异性。例如,在测定的300只仔猪中粗蛋白和氨基酸的吸收率     

森林能削弱温室效应——如果“植树”能拯救人类,那么需有多少树

随着大气中CO_2的聚积,地球气候逐步变暖。大气中CO_2的增加已有大量资料论及,预计到21世纪中叶,大气中的CO_2能增加1倍。产生CO_2的主要根源是化石燃料的燃烧;当然,生物量的消除也会引起大地气候变化,尤其是热带森林,也是CO_2来源的一个方面。尽管气候变暖的程度还没有证实,但是,许多科学家已作出了这种预测。     

Myricetin glycosides from Licania densiflora

Dried leaves of Licania densiflora yielded five myricetin glycosides: myricetin 3'-methylether-3-O-glucoside (1), myricetin 3'-methylether-3-O-galactoside (2), myricetin 4'-methylether-3-O-rhamnoside (3), myricetin 3',5'-dimethylether-3-O-glucoside (4), and myricetin 3',5'-dimethylether-3-O-rhamnoside (5). Their structures were elucidated by spectroscopic methods including mono- and bi-dimensional NMR techniques.