首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 109 毫秒
1.
农产品和饲料中常见真菌毒素的种类和危害   总被引:1,自引:0,他引:1  
对黄曲霉毒素、赭曲霉毒素、伏马菌素、玉米赤霉烯酮、脱氧雪腐镰刀菌烯醇、展青霉素等常见真菌毒素的来源、种类、特点、毒性等进行了介绍,并进一步阐述真菌毒素对人类和动物健康的影响及国内外对农产品及饲料中真菌毒素控制的相关法律、法规和标准.  相似文献   

2.
玉米赤霉烯酮的毒害及脱毒技术的研究进展   总被引:3,自引:0,他引:3  
玉米赤霉烯酮是由镰刀菌产生的一种对人畜有害的霉菌毒素,介绍了玉米赤霉烯酮的毒害及其脱毒技术的最新研究进展。  相似文献   

3.
PP333对怀地黄种质离体保存的影响   总被引:2,自引:0,他引:2  
研究了PP333对怀地黄"85-5"脱毒苗离体保存的影响.结果表明:适宜浓度PP333(1~2 mg.L-1,单位下同)可以延缓脱毒苗的生长速度,延长其保存时间,减少其继代次数;高浓度PP333(4~8)对其生长产生毒害作用,不利于种质保存.适宜怀地黄脱毒苗离体保存的培养基为MS+NAA0.02+6-BA0.2+PP3331,在该培养基上保存180 d后,存活率达68%,恢复培养时生长正常,成活率达100%.  相似文献   

4.
生物在生存竞争中,产生具有抑制或驱避、毒害作用的反抗物质进行化学防御,这是促进生物协同进化的一个重要因素。本文论述了植物与动物、植物与微生物以及动物与微生物间的化学防御及其协同进化的关系。  相似文献   

5.
研究旨在降解酒精糟中几种毒素(呕吐毒素、伏马菌素、黄曲霉毒素),为酒精糟制成饲料奠定基础。利用实验得到的一株能够很好降解玉米酒糟毒素菌种酵母19-1,以酒精糟和麸皮为发酵底物进行固态发酵,通过正交试验对固态发酵过程中添加的营养条件进行研究,测得发酵物毒素的含量,并通过重复最佳配方实验对结果进行验证。综合3种毒素测得情况,确定酵母19-1降解玉米酒精糟毒素的最优搭配组合为硫酸铵0%、水12 m L、硫酸镁0.015%、磷酸二氢钾0.05%、葡萄糖0%。  相似文献   

6.
利用微生物将棉籽中游离棉酚脱毒的研究   总被引:18,自引:0,他引:18  
本文通过添加棉酚的培养基进行微生物的自然筛选和诱变育种,获得5株对棉酚有高脱毒率而不产黄曲霉毒素的霉菌,对未经榨油的棉籽仁粉的微生物脱毒率达60%—74%。它们分别属于梨孢帚霉属(Scopulariopsis sp.)、曲霉属(Aspergillus sp.)、串珠霉属(Monilia sp.)和红曲霉属(Monascus sp.)。通过测定经固态发酵脱毒处理后棉籽仁粉、饼粉中游离棉酚的残留量证实棉籽饼脱毒后游离棉酚含量达到安全标准。对发酵后棉籽仁粉、饼粉的动物毒性试验和营养分析,结果也表明发酵后的棉籽仁粉、饼粉毒性大为减少而营养价值却有所提高。  相似文献   

7.
三硝基甲苯是一种芳香族硝基化合物,有强烈的爆炸性并对人和动物有毒害作用。通常对其保管和使用非常严密,很少引起家畜及动物中毒。人有在生产使用三硝基甲苯时发生中毒的报道。警犬由于特殊的原因(如接受搜索TNT的训练等),接触的机会  相似文献   

8.
应用伊维菌素驱杀实验动物体内外寄生虫   总被引:1,自引:0,他引:1  
目的寻找一种安全有效的驱杀实验动物体内外寄生虫的药物。方法将携带鼠癣螨雄性小鼠随机分为3组,雌鼠也随机分为3组;将携带鼠隐匿管状线虫卵雄性小鼠随机分为3组,雌鼠也随机分为3组。通过3周饮用浓度分别为0.1%、0.5%和1.0%的伊维菌素来观察驱杀效果。结果 3个浓度的伊维菌素对实验动物鼠癣螨和鼠隐匿管状线虫均有较好的驱杀效果。结论伊维菌素可作为一种安全有效驱杀实验动物体内外寄生虫的药物使用。  相似文献   

9.
湖北麦冬脱毒苗的生长发育与产量效应研究   总被引:1,自引:0,他引:1  
通过田间试验和盆栽对比试验对湖北麦冬茎尖脱毒苗与未脱毒苗的生长发育和产量进行了比较.结果表明,茎尖脱毒苗的产量极显著地高于未脱毒苗;单株分蘖数、块根数、根系活力均显著地高于未脱毒苗;茎尖脱毒苗和未脱毒苗的折干率差异不显著.  相似文献   

10.
本试验从土壤中分离纯化得到多种微生物,并对各种微生物进行了相同的菜籽饼脱毒试验,测定脱毒效果。试验证明单一微生物的GS脱毒率一般较低(<40%),属内霉菌复配脱毒率有所增加,属问霉菌复配,脱毒率又有很大程度上的提高。多种微生物远缘复配达到了较理想的脱毒效果,GS脱毒率达到99%以上。  相似文献   

11.
Experiments were performed on 13 Wister rats. Fastblus (FB) was injected into subcutaneous tissue in perineum area and nuclear yellow (NY) was injected into subserous lamina of the bladder wall, respectively. FB, NY and FB+ NY were mostly found in the spinal ganglions of L6, S1 ans S2 segments. The numbers of FB, NY and FB+ NY labeled cells were 146, 186 and 81, in a total of 463 labeled cells and their proportion was 40%. 51% and 9%, respectively. The result indicates that the spinal ganglion neurons dually innervate both the somatic and visceral tissues, and the convergence of somato-visceral sensory pathways might occur in the spinal ganglion cells.  相似文献   

12.
在两门子FB41与FB43软模块平台下,设计了夹套锅炉温度控制系统.首先,对系统的硬件部分进行了设计;接着对FB41与FB43模块的算法进行了介绍并详细阐述了 FB41与FB43组合在一起实现控制的过程,在此基础上,对程序进行了设计;最后通过改变给定值与干扰信号对系统进行了验证.结果表明:系统的输出能快速准确地跟踪给定信号,达到了良好的控制效果.  相似文献   

13.
Src激酶抑制剂FB2抗前列腺癌作用研究   总被引:1,自引:0,他引:1  
探讨Src激酶抑制剂FB2抗前列腺癌的作用及机制.整体动物实验观察FB2对人前列腺癌PC-3细胞在裸鼠异体中生长的影响;MMT、克隆原形成、细胞黏附试验观察FB2对肿瘤细胞增殖、黏附的影响;流式细胞术分析FB2对细胞周期的影响;Western blot观察细胞及组织内Src及p-Src表达.实验结果表明FB2抑制PC-3细胞裸鼠移植瘤的生长;FB2抑制PC-3细胞增殖及对基底膜成分的黏附,并将细胞周期阻滞于G1期;机制研究表明,FB2抑制PC-3细胞及瘤组织中Src激酶Tyr416磷酸化.因此Src激酶抑制剂FB2在体内外均有较强的抗前列腺癌作用,其机制可能与抑制Src激酶Tyr416磷酸化有关.  相似文献   

14.
根据双正交小波精确重构条件,推导出了7/5双正交小波滤波器组的参数化表达式.该表达式参数可随意取值,因此能够任意构造具有不同特征的7/5线性相位小波滤波器.作为构造实例,构造了具有最佳编码增益的有理系数7/5小波滤波器.实验表明,它具有与CDF 9/7小波滤波器相似的图像压缩性能,而且其提升小波变换的计算效率可提高20%.  相似文献   

15.
The wool fabrics were treated with low temperature plasma (LTP) using three different gases, namely (ⅰ) oxygen, (ⅱ) nitrogen and (ⅲ) 25% hydrogen/75% nitrogen gas mixture. After LTP treatment, the low stress mechanical properties, surface properties and thermal properties of the fabrics were investigated by kES-F (Kawabata Evaluation System) Instruments composing of KES-FBI for tensile and shear property measurement, KES-FB2 for pure bending measurement, kES-FB3 for compression measurement, KES-FB4 for surface friction and surface roughness measurement, and KES-F7 for thermal property measurement. The first four instruments were used for investigating the charaeterlstlc aspect related to fabrle hand while the last one was mainly for the fabric comfort. The properties of LTP treated fabrics under the effect of different gases were compared with the untreated fabric quantitatively.  相似文献   

16.
本文导出了FB随机场的统计特性,提出并证明了FB随机场的时域及频域的遍历定理,给出了参数H的估计方法。  相似文献   

17.
通过对移相控制全桥零电压开关变换器的运行过程的详细分析,研究了超前桥臂与滞后桥臂的开关互换动作在变换器功率传输过程中所起的作用,另外,由于变换器的输出滤波部分与Buck变换器类似,因此,可将在Buck变换器闭环控制设计中获得成功应用的滑膜控制引入移相控制全桥零电压开关变换器中,仿真结果表明,滑膜控制的变换器闭环系统对输入电源扰动具有较好的鲁棒性,对负载扰动的瞬态响应特性也较为理想。  相似文献   

18.
Wolfe ND  Dunavan CP  Diamond J 《Nature》2007,447(7142):279-283
Many of the major human infectious diseases, including some now confined to humans and absent from animals, are 'new' ones that arose only after the origins of agriculture. Where did they come from? Why are they overwhelmingly of Old World origins? Here we show that answers to these questions are different for tropical and temperate diseases; for instance, in the relative importance of domestic animals and wild primates as sources. We identify five intermediate stages through which a pathogen exclusively infecting animals may become transformed into a pathogen exclusively infecting humans. We propose an initiative to resolve disputed origins of major diseases, and a global early warning system to monitor pathogens infecting individuals exposed to wild animals.  相似文献   

19.
W Chia  S McGill  R Karp  D Gubb  M Ashburner 《Nature》1985,316(6023):81-83
The TE1 family of transposable elements (TEs) of Drosophila consists of unusually large transposons, cytologically visible in larval polytene chromosomes as one or more bands. They are composite elements, as their termini consist of foldback (FB) sequences which are themselves transposable. The location of FB elements at the termini of transposable elements suggests that these sequences have a direct role in the genetic instability of TEs. To investigate the structural and phenotypic consequence of TE excision, we have cloned genomic DNA required for the expression of the no-ocelli (noc) gene of Drosophila; this gene has been mutated by the insertion of TE146, a member of the TE1 family carrying six polytene chromosome bands including functional copies of the white (w+) and roughest (rst+) genes. As reported here, our experiments indicate that the spontaneous excision of TE146, which results in the loss of the w+ and rst+ markers, can occur either as a single-step event or following a partial internal deletion. In either case, the end product is an imprecise excision in which a residual portion of the element, varying in size from 3 to 10 kilobases (kb), is left at the insertion site. These residual sequences share homology with the FB family. Furthermore, despite their imprecise nature, all these spontaneous excisions restore a wild-type noc+ phenotype.  相似文献   

20.
为提高开关电源效率,在对全桥移相PWM(FB-PWM)变换器工作原理及其工作状态分析的基础上,介绍了FB-PWM变换器实现零电压转换的条件,并提出以能量和时间两个概念分析的方法,利用集成控制芯片ML4818作为移相控制核心设计了零电压转换的FB-PWM(ZVS FB-PWM)变换器,并完成了实验,结果证明分析和设计是正确的。  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号