饲料中无机元素分析方法研究进展

饲料中所含的无机元素对动物生长具有重要意义。在饲料中过量添加无机元素会导致环境污染问题,也会通过食物链最终危害消费者的身体健康,因此,对饲料产品中的无机元素进行检测和动态监控尤为重要。综述了近年来饲料中无机元素含量检测主要应用的前处理方法及其含量检测技术,分析了不同前处理方法和含量检测技术的优点和不足,以期为饲料中无机元素分析方法的科学、合理应用提供参考。     

优化预处理及脱毒工艺以制备玉米芯半纤维素水解液

为了降低玉米芯半纤维素水解液中的乙酸、糠醛和酚类等有毒物质含量,使可利用糖类含量增加。本研究以玉米芯为原料制备水解液,对预处理及脱毒工艺进行优化,并利用高效液相色谱(HPLC)检测优化效果。结果表明,10~20目的玉米芯在10%氨水浸泡24 h后,可将乙酸和酚类物质的脱除率,分别提高至93.4%和32.3%,而糠醛的含量也大大降低。经过真空浓缩、CaO脱毒以及2%活性炭吸附后,使有毒物质含量再次降低,此时的水解液可完全用于菌株的发酵试验,达到了去除的目的。本文所得到的最佳水解液处理步骤,其结果符合菌株发酵用标准,说明水解液处理方式的不同,直接影响着水解液的制备。这为研究和利用木质纤维素等可再生资源提供了思路,也为发酵生产奠定了理论基础。     

施肥对特高多花黑麦草初级生产力影响的研究

通过N、P、K肥单施及其不同配比混施，研究了施肥对提高特高多花黑麦草初级生产力的影响。结果表明，N、P、K肥单施和不同配比混施均能提高特高多花黑麦草的鲜草产量，但混施的增产效果比单施更好。施用尿素400kg／hm^2，过磷酸钙500kg／hm^2，硫酸钾200kg／hm^2，产量最高，播种后8周达到11723．3kg／hm^2。     

水稻中系8541与中系8240光合特性的比较研究

本文通过光合作用参数的测定,详细的研究了中系8541和8240两种不同产量水平的水稻品种的光合特性.论述了在含等量叶绿素的条件下,中系8541和中系8240之间在对光谱的吸收、叶片的光合作用量子转化效率,叶绿体的PSⅡ(光系统Ⅱ)潜在活性(Fv/F_0)和原初光能转化效率(Fv/Fm等的主要区别.实验结果说明,上述各光合作用参数中系8541都优于中系8240.不仅如此.在Mg~(2+)作用下,Fv/Fo和Fv/Fm比值的提高以及Mg~(2+)对两个光系统激发能分配的调节能力中系8541也强于中系8240.     

黄鳍鲷肝细胞体外培养研究

以黄鳍鲷肝脏细胞为材料 ,研究其肝细胞体外培养适宜的 p H、血清浓度、谷氨酰胺等条件 ,并进行传代培养试验。结果表明 ,培养液为 :MEM含 2 0 %小牛血清、15 g/ L L-谷氨酰胺及 p H 6 .9～ 7.1时 ,在 2 3℃中静置培养 ,黄鳍鲷肝细胞生长良好 ,3～ 5 d长满单层 ,细胞主要为成纤维细胞状 ,并能顺利传代。细胞动力学试验表明 :传代细胞 1～ 2代为适应期 ,3～ 5代为旺盛期 ,6代之后表现出衰老现象     

Resistance to Botrytis cinerea in Solanum lycopersicoides is Dominant in Hybrids with Tomato, and Involves induced Hyphal Death

Botrytis cinerea causes gray mold disease and affects hundreds of plant species, including tomato (Lycopersicon esculentum). The wild nightshade, Solanum lycopersicoides, is cross compatible with tomato and is more resistant to B. cinerea, thus representing a potential source for crop improvement. Tests involving droplet inoculation of detached leaves and spray inoculation of entire seedlings demonstrated that resistance to B. cinerea varies among S. lycopersicoides accessions, with S. lycopersicoides LA2951 being the most resistant accession tested. Expression of resistance in the intergeneric hybrid (L. esculentum cv. 'VF36' × S. lycopersicoides LA2951) suggested that resistance is at least partially dominant in tomato. A green fluorescent protein-tagged B. cinerea strain was used for confocal microscopic comparison of infection in leaves of S. lycopersicoides and tomato. Even though S. lycopersicoides supported spore germination, there was evidence for hyphal lysis and death 3 days after inoculation, at a time when lesions were expanding on susceptible tomato plants. The reduced frequency of B. cinerea lesion spread on S. lycopersicoides explains why this fungus produced fewer spores in this wild nightshade than in tomato.     

Contrast‐Enhanced Ultrasound Examination for the Assessment of Renal Perfusion in Cats with Chronic Kidney Disease

Background

Contrast‐enhanced ultrasound examination (CEUS) is a functional imaging technique allowing noninvasive assessment of tissue perfusion. Studies in humans show that the technique holds great potential to be used in the diagnosis of chronic kidney disease (CKD). However, data in veterinary medicine are currently lacking.

Objectives

To evaluate renal perfusion using CEUS in cats with CKD.

Animals

Fourteen client‐owned cats with CKD and 43 healthy control cats.

Methods

Prospective case‐controlled clinical trial using CEUS to evaluate renal perfusion in cats with CKD compared to healthy control cats. Time‐intensity curves were created, and perfusion parameters were calculated using off‐line software. A linear mixed model was used to examine differences between perfusion parameters of cats with CKD and healthy cats.

Results

In cats with CKD, longer time to peak and shorter mean transit times were observed for the renal cortex. In contrast, a shorter time to peak and rise time were seen for the renal medulla. The findings for the renal cortex indicate decreased blood velocity and shorter total duration of enhancement, likely caused by increased vascular resistance in CKD. Increased blood velocity in the renal medulla has not been described before and may be because of a different response to regulatory factors in cortex and medulla.

Conclusions and Clinical Importance

Contrast‐enhanced ultrasound examination was capable of detecting perfusion changes in cats with CKD. Further research is warranted to assess the diagnostic capabilities of CEUS in early stage of the disease process.     

不同优质粳稻花药对低温和激素处理的培养响应

以3份优质粳稻品种为供试材料,研究了3种低温预处理和9个激素处理组合对离体花药培养的影响。结果表明:供试材料花药对低温预处理的响应存在明显差异,对激素处理组合的响应也存在一定差异。