Molecular cloning and expression of kidney‐type glutaminase from common carp (Cyprinus carpio) and its up‐regulation by glutamine in primary culture enterocyte

Glutaminase (GLS) is the key enzyme of glutamine (Gln) metabolism and utilization. In this study, a cDNA encoding GLS protein was identified from common carp Cyprinus carpio intestine. The open reading frame of GLS cDNA encodes a polypeptide of 595 amino acids, which shows a high similarity with its zebrafish Danio rerio counterpart. Bioinformatic analysis showed the protein belongs to kidney‐type GLS. The putative protein has glutaminase domain and ankyrin repeats domain, which are highly conserved among vertebrate orthologues. Real‐time quantitative PCR analysis revealed that the abundance of GLS mRNA was the highest in the white muscle, followed by the brain, eyeball and pituitary. Glutaminase was ubiquitously expressed in all intestinal segments of common carp. The activity of GLS did not distribute uniformly along the entire length of the intestine. In primary culture enterocyte, and the expression of GLS mRNA is up‐regulated quickly and effectively by Gln.     

马铃薯生产全程机械化技术推广实践与思考

介绍了马铃薯生产过程及机械化技术,并以重庆市马铃薯全程机械化技术推广实践为例,总结了实施情况,分析了存在的问题,提出了发展建议。      

内蒙古典型草原草畜系统适宜放牧率的研究Ⅰ.以绵羊增重及经济效益为管理目标

(1)绵羊个体增重与放牧率呈线性负相关,个体最大增重临界放牧率,因季节不同而变化,随着个体增重与放牧率回归系数b绝对值的增大而降低,以始、终放牧期间所得临界放牧率最小,(2.04羊/hm²)。(2)公顷增重与放牧率的关系符合二次曲线,在达到公顷最大增重以前,随着放牧率的增大而增大,之后则随着放牧率的增大而下降,平均543羊/hm²。(3)公顷最大增重并不一定获取公顷最大利润,主要视买卖价格及其差值而定。(4)以冷蒿小禾草为主的退化草原,宜以个体最大增重的适宜放牧率作为管理标准,以使该类草原在利用中得以恢复。     

Both TGF-β1 and Smad4 regulate type I collagen expression in the muscle of grass carp,Ctenopharyngodon idella

Fish Physiology and Biochemistry - Type I collagen is proven to make an important contribution to fish muscle quality. Our previous study has shown the Smad4-dependent regulation of type I collagen...     

莰酮对蚜虫生物活性的研究

进行了樟树(CinnamomumcamphoraL.)中的莰酮(CamphorC10H160)对蚜虫的触杀、熏蒸毒力和拒食活性研究。结果表明,处理后24h莰酮对菜缢管蚜、桃蚜和棉蚜触杀作用的LD50分别为3.12×10-3,2.04×10-3,0.68×10-3 ng/头,熏蒸作用的LC50分别为3.44,2.56,1.06mg/L,拒食作用的AFC50分别为3.34,2.98,1.32mg/L。经回归和相关分析,处理浓度与作用效果相关性均达到极显著或显著水平。莰酮在田间防治菜缢管蚜的效果显著。     

应用不同国家标准对结构胶合板胶合强度检测的比较研究

胶合强度和木破率是评价结构用胶合板胶合性能的重要指标,而中、日、美三国结构用胶合板标准要求的胶合强度测试试件在开槽深度及试件长度上存在差别。为研究不同国家标准要求对结构胶合板胶合性能测试结果的影响,笔者进行了实验,结果表明,槽口深度对结构胶合板胶合强度测试结果的影响极显著,而试件长度对其影响不显著。且美国结构用胶合板标准对胶合强度要求相对中、日两国标准高。     

苹果苗断根施肥机的设计与试验

苹果苗倒栽作业是苗圃园艺生产作业中将矮化中间砧半成品苗倒栽进行嫁接果树穗种的一项准备工作,工作强度大.为此,根据苹果苗苗圃园艺作业要求,设计了L型断根铲的断根施肥机.田间试验表明:作业参数为断根深度178mm,工作幅宽450mm,施肥量300kg/hm2,配套动力22kW以上轮式拖拉机能够实现对苹果苗的断根和施肥联合作业,可提高效率和减轻工作强度.     

4UMS-390Ⅱ型木薯收获机的研制

木薯块根是工业上主要的制淀粉原料之一,世界上木薯全部产量的65%用于人类食物,但国内木薯收获机的研制尚未见到相关系统报道.为此,阐述了一种木薯收获机的主要结构、工作原理、主要技术参数及试验结果.试验结果表明,该机型满足设计要求,且能够满足生产要求.     

Numerical Analysis of Acoustic Environment with Finite Element Method

The acoustic environment of highway tunnel is complex and has influences on the driving safety and comfort. In case of emergency, evacuation information is difficult to transfer. Finite element method is used for calculating highway tunnel acoustic modal and attenuation characteristics. The results show that acoustic mode of highway tunnel has symmetry in the horizontal pressure amplitude of symmetry regional is equal and phase is the same or opposite. The higher modal frequency, the greater sound pressure amplitude is, and the effect of tunnel length on modal frequency is smaller. Decay curves of pressure level at each point in the highway tunnel over time are nonlinear. After the source excitation, in 1.5 s, attenuation rate is faster than that of few seconds later and the attenuation time of sound pressure level 30 dB is 5.5 to 7 s.     

我国水稻空间诱变育种研究动态与展望

简要地综述了对水稻空间诱变育种的研究概况、取得的成果及对SP后代遗传变异规律的有关研究,分析了水稻空间诱变育种的方法;指出空间诱变育种是水稻育种的一条重要途径。