癸氧喹酯干混悬剂防治人工感染鸡球虫病的效果试验

通过对14日龄岭南黄鸡人工感染柔嫩艾美耳球虫卵囊,测定国家四类新兽药癸氧喹酯干混悬剂的抗球虫作用。研究结果表明,新兽药癸氧喹酯干混悬剂按照推荐剂量0.25g/L(15mg/L)饮水给药对鸡球虫病表现出高效的抗球虫活性,具有良好的预防鸡球虫病效果,达到100%的保护率,抗球虫指数高达202.2。     

油松毛虫幼虫种群动态格局的研究

本文在以6种分布型指数测定油松毛虫(Dendrolimus tabulaeformis Tsai et Liu)幼虫种群静态空间格局的基础上,通过聚类分析,可将油松毛虫幼虫种群在上树过程中的水平格局和垂直格局聚为两类:即前期型和中后期型;其6种分布型指数可分为三类:即(1)m~*/m,C_A,I_δ;(2)入;(3)C,L。     

新媒体时代科普工作原则--基于CAS理论视角

简述了新媒体和复杂自适应系统（CAS）理论的相关概念,辨析了传统科普和新媒体时代科普的不同,指出了新媒体时代的科普系统是CAS ,提出了用CAS理论指导新媒体时代科普工作的几点原则。     

Study of wavelet denoising in apple's charge-coupled device near-infrared spectroscopy

Discrete wavelet transform was used to eliminate the noise in the charge-coupled device near-infrared (CCD-NIR) spectra of apple. The influence of three parameters (wavelet function, decomposition level, and threshold) on the predictive ability of the calibration model was investigated. The result showed that the db, sym, and bior wavelet families performed well, while the coif, dmey, and haar wavelets were not able to denoise effectively. The best decomposition level was 2. The threshold selection rules of the default, Birge-Massart, and Penalty had good denoising results, while SURE, Sqtwolog, Heuristic SURE, and Minimax set all detailed coefficients to zero due to their high threshold values. The best denoising result was obtained with the combination of the bior3.3 wavelet function, two levels of decomposition, default threshold selection rule, and the soft thresholding method. The optimal model of soluble solids content was constructed. The relative standard deviation of prediction decreased from 7.79 to 5.82% after wavelet denoising.     

Inhibition of low-density lipoprotein oxidation and oxidative burst in polymorphonuclear neutrophils by caffeic acid and hispidin derivatives isolated from sword brake fern (Pteris ensiformis Burm.)

Several antioxidant compounds have been previously identified from sword brake fern (Pteris ensiformis Burm.) by DPPH bleaching and Trolox equivalent antioxidant capacity (TEAC) analyses. Among the isolates, 7-O-caffeoylhydroxymaltol 3-O-beta-D-glucopyranoside and hispidin 4-O-beta- D-glucopyranoside [6-(3,4-dihydroxystyryl)-4-O-beta-D-glucopyranoside-2-pyrone] were two new compounds. The aim of this study is to elucidate the possible effect of the aqueous extract of sword brake fern (SBF) and these two compounds in preventing atherosclerosis. The results demonstrated that SBF and these two compounds strongly inhibited Cu2+-mediated low-density lipoprotein (LDL) oxidation measured by thiobarbituric acid-reactive substances assay (TBARS), conjugated diene production, and relative electrophoretic mobility. The commercial antioxidant dl-alpha-tocopherol showed lower antioxidant activity than these two compounds at the same molecular concentration. SBF and these two compounds also suppressed N-formylmethionyl-leucylphenylalanine (fMLP)-stimulated reactive oxygen species (ROS) production in human polymorphonuclear neutrophils (PMN). These findings indicate that sword brake fern may prevent atherosclerosis via inhibition of both LDL oxidation and ROS production.     

药用植物连作障碍研究进展

中医是我国特有的传统文化和产业,优质中药材是关系国计民生的战略性资源.近年来随着国内外对中药材需求的日益增长,人工栽培药用植物的种类和面积大幅增加,由于耕地有限、种植条件及道地性等因素的限制,在药用植物集约化种植过程中,普遍存在严重的连作障碍问题,在以块根类入药的药用植物上表现尤为严重.目前连作障碍已经成为制约中药材产量和品质的关键因素,严重阻碍中药材规范化种植和产业化发展.从药用植物连作障碍危害、形成机理以及调控措施的最新研究进展进行总结,指出连作障碍问题主要是植物-土壤-微生物三者共同作用的结果,分析了当前药用植物连作障碍形成的3个主要原因,包括土壤养分亏缺和失衡、化感自毒作用以及根际微生态破坏导致土传病害加重.提出了连作障碍的调控措施,包括优良品系选育、土壤灭菌、建立合理的耕种制度、施用微生物菌肥,并对未来研究的方向和重点进行了探讨,以期为克服药用植物连作障碍的栽培管理提供科学参考.     

2008―2021年新疆审定长绒棉品种主要性状演变分析

为全面了解近年新疆育成长绒棉品种的特征特性,对2008―2021年新疆维吾尔自治区主要农作物品种审定委员会审定的43个早中熟长绒棉品种和4个当前待审品种的主要性状演变情况进行分析.结果表明:2012年以来审定品种的铃重较之前明显增加,普遍在3.40 g以上;衣分总体表现较为平稳,皮棉产量受气候环境等因素影响波动较大;纤...     

The siderophore-interacting protein is involved in iron acquisition and virulence of Riemerella anatipestifer strain CH3

Riemerella anatipestifer causes epizootic infectious disease in poultry and serious economic losses especially to the duck industry. However, little is known regarding the molecular basis of its pathogenesis. The ability to acquire iron under low-iron conditions is related to the virulence of a variety of bacterial pathogens. In this study, a sip (Riean_1281) deletion mutant CH3Δsip was constructed and characterized for iron-limited growth, biofilm formation, and pathogenicity to ducklings. Results showed that siderophore-interacting protein (SIP) was involved in iron utilization and the sip deletion significantly reduced biofilm formation and adherence to and invasion of Vero cells. In addition, the sip gene was absent in 1 of 24 (4.17%) virulent strains and 2 of 3 (66.7%) avirulent strains of R. anatipestifer, and the sip gene from six R. anatipestifer strains, which belong to serotypes 1, 2, and 10, respectively, shared 100% amino acid identities to those of R. anatipestifer strains DSM15868 and RA-GD. These results suggested that siderophore-mediated iron acquisition may be an important iron-uptake pathway in R. anatipestifer. Animal experiments indicated that the median lethal dose of the CH3Δsip mutant in ducklings was about 35-fold higher than that of the wild-type CH3 strain. Thus, our results demonstrated that R. anatipestifer SIP was involved in iron acquisition and necessary for its optimal virulence.     

Soil acidification induced by intensive agricultural use depending on climate

Journal of Soils and Sediments - Soil acidification is a major issue in agricultural ecosystems. However, how agricultural land uses shape the soil pH pattern and affect soil acidification on a...     

广藿香种质资源及栽培技术研究进展

广藿香为多年生芳香草本或半灌木植物,是我国著名的南药之一。通常以其干燥地上部分入药,具有芳香化浊、开胃止呕、发表解暑等功效,是多种中成药的重要原料。此外,以其提取的广藿香油是世界上医药工业和轻化工业的重要原料,经济价值高,应用市场前景广阔。广藿香为热带地区引入我国栽培,种质类型单一,遗传基础狭窄,资源极为有限。由于长期的自然环境和人工栽培的影响,广藿香种质产生了一些变异和分化,目前主要分布于我国广东、广西、福建和海南等南方省（区）,按照产地将其分为牌香、肇香、湛香和南香4种。广藿香在种植过程中,存在严重的连作障碍现象,且由于田间管理粗放,其产量和品质不稳定,受品种、产地、栽培技术等多方面因素影响。近年来,随着分子生药学的发展,其主要药用成分广藿香醇和广藿香酮的内在分子调控机制相关研究开展顺利,目前关于广藿香的研究大多集中在其有效成分的药效药理、生物合成及代谢调控方面,而对种质资源及栽培技术的系统性研究不足。优良的品种和高效规范的种植技术是药材产量和质量稳定的基础,为充分利用广藿香药材资源,进一步推广广藿香规模化和产业化发展,本文主要综述了广藿香的生物学特性、种质资源研究现状、栽培技术中的瓶颈及产业发展过程中存在的问题,指出了广藿香栽培过程中养分管理技术缺乏,连作障碍问题严重,提出要加强广藿香的繁殖技术和品种选育研究,积极推进广藿香的规范化种植,以期为广藿香的产业发展和开发利用提供参考。