The Microstructure,Antibacterial and Antitumor Activities of Chitosan Oligosaccharides and Derivatives

Chitosan obtained from abundant marine resources has been proven to have a variety of biological activities. However, due to its poor water solubility, chitosan application is limited, and the degradation products of chitosan oligosaccharides are better than chitosan regarding performance. Chitosan oligosaccharides have two kinds of active groups, amino and hydroxyl groups, which can form a variety of derivatives, and the properties of these derivatives can be further improved. In this review, the key structures of chitosan oligosaccharides and recent studies on chitosan oligosaccharide derivatives, including their synthesis methods, are described. Finally, the antimicrobial and antitumor applications of chitosan oligosaccharides and their derivatives are discussed.     

秦岭地理新分布植物

报道了８种、分别隶属于８个科的植物为秦岭地理分布新记录,全部标本存于华东师范大学生物系植物标本室内。     

秸秆粉碎机实际生产效能改进研究

随着我国生物质能开发与利用地不断提高,生物质颗粒燃料需求量逐年提高,生物质颗粒燃料生产逐步向规模化、效益化方向发展,秸秆等生物质的粉碎则至关重要。分析各种锤片式粉碎机在实际生产过程中的效能,并与改进后的粉碎机效能进行对比,以提高现有秸秆粉碎机效能,逐步标准化各主要部件,为生物质颗粒燃料规模化生产提供基础保障。     

新疆杏属植物过氧化物酶儿茶酚氧化酶同工酶分析

根据酶谱及其分布率、扫描图的异同分析表明,杏不同种间的两种酶谱均有明显的差异,而种内品种间的差异较小,如西伯利亚杏(A.sibirica(L) lam)的酶谱较特别,与普通杏(A.vulgarislam)、辽杏(A.mandshurica(Maxim) Skvortz)、紫杏(A.dasycarpa Ehrh)有较大差异;紫杏有6条共同酶带,而普通杏中的白新那尔、阿克牙格勒克等与之相近;辽杏与紫杏有明显差异,但与栽培杏中的墨玉001、卡拉胡安娜等品种的酶谱较接近;普通杏中的野生杏明显地较栽培杏多一条强带.杏属植物有4条共同酶带,这4条酶带在各品种的分布率为98.7%～100%,2种酶活性均以CⅡ区最强,酶活性占60%～90%;其次为CⅠ区,酶活性占10%～30%,PⅢ、CⅢ区活性最弱,小于10%,两种酶有共同的趋势,但儿茶酚氧化酶的弱带有广泛的变异.     

狐狸早期妊娠诊断初步研究

利用玫瑰花抑制实验,检测蓝狐妊娠前后免疫机能变化。以确定蓝狐孕血清中是否也存在早孕因子现象。为进一步研究狐狸的早孕检测方法提供基础资料。通过检测雌狐配种前后花抑滴度（ＲＩＴｓ）值。结果表明：怀孕动物与发情期、非妊娠动物的ＲＩＴｓ是有区别的。在实验中所检测发情期雌狐与未孕雌狐血清ＲＩＴｓ值均小于或等于１２,而妊娠雌狐血清ＲＩＴｓ值一般都在１８以上。据此,可以进行雌狐早期妊娠诊断。     

不同干燥方式对白萝卜干制品品质的影响

为了解不同干燥方式对白萝卜干制品品质和微观结构的影响及变化情况,以新鲜白萝卜为原料,采用振动远红外干燥方式和传统远红外干燥方式对白萝卜进行干燥,研究其对营养成分、复水比、干燥时间、脱水速率、感官品质以及微观结构的影响。结果表明:振动远红外干燥方式干制的白萝卜样品中蛋白质、维生素C、芥子油苷、总糖、脂肪和复水比明显高于传统远红外干燥方式制得的样品;相比于传统远红外干燥方式,干燥时间缩短了0.67 h,脱水速率提高了40.58%;干制品感官品质和微观结构均优于传统远红外干燥方式。研究为远红外干燥方式在白萝卜方面的应用提供理论依据与技术参考。     

水稻不同氮肥量水平下铜肥肥效的研究

本文研究了微量元素铜在同样的氮肥量水平下对水稻生育的影响。结果表明,在氮、磷、钾配合施用的基础上,适量施用铜肥,可提高氮肥利用率,增加有效分蘖率,减少空秕率,提高抗稻瘟病、抗倒伏能力和产量。铜肥不仅促进水稻的氮素吸收,还促进氮素同化利用,氮肥量水平高时更为明显。     

原条量材设计有向图及其解的研究

原条量材设计是在原条造材前对原条各部位用途进行优化设计的过程。本文在国内外有关专家的研究基础上,提出用图论中的有向图理论,解决原条量材设计中的优化问题。用锯口线为点x_d,两个锯口线间的木段为弧y_n,描绘出由点集X和弧集Y组成的原条量材设计有向图T=(X,Y)。由于弧的权ω_(ij)是由木段的售价赋给,且保证ω_(ij)≥0,故用Dij kstra算法,求出最佳木材利用率下原条售价最高的路。     

Effects of thyroxine,cod liver oil and potassium iodide on growth and survival of juvenile seahorse,Hippocampus barbouri

Low survival at early stage is the bottleneck in seahorse aquaculture, particularly in the feeding aspect since newborn seahorses must feed immediately upon birth to sustain themselves. Seahorses are visual predator, therefore preferred live feed such as zooplankton. In aquaculture, the most common live feed used is Artemia. In this study, two experiments were conducted to determine the effect of different Artemia enrichment on the growth and survival of newborn Hippocampus barbouri. In the first experiment, six treatments using Artemia enriched with Culture Selco Plus? (SELCO), thyroxine (T4), potassium iodide (KI), cod liver oil (CLO), cod liver oil in combination with thyroxine (CLO + T4) and potassium iodide (CLO+KI) were fed to newborn H. barbouri. Newly hatched Artemia were used as control. At the end of first experiment, treatments using CLO + T4 produced juvenile H. barbouri with the best (p < .05) wet weight (0.142 ± 0.000 g), while juvenile in treatment CLO+KI recorded the highest (p < .05) standard length (3.947 ± 0.014 cm). Subsequently, a second experiment was carried out using the two best enrichment (CLO + T4 and CLO + KI) from the first experiment, but given at different frequency (daily, twice a week, once a week, once in 2 weeks). Daily enrichment using both CLO + T4 and CLO + KI showed no significant (p > .05) difference in growth performance and survival of juvenile of H. barbouri. Interestingly, juvenile fed CLO + T4 enriched Artemia at frequency of twice a week also has no significant difference (p > .05) in survival and growth performance (except for final standard length) when compared with treatment CLO + T4 at daily frequency.     

Amino Acid Composition of Developing Larval Freshwater Prawn Macrobrachium rosenbergii

Abstract.— Amino acid profiles of freshwater prawn Macrobrachium rosenbergii were determined during early larval stages (I-IX) to provide some baseline biochemical information of the growing larvae. The larvae obtained from several females were stocked into three 250-L tanks at a density of 30 larvae/L. The feeding regime consisted of newly hatched Artemia nauplii and egg custard containing 5% cod liver oil. For each developmental stage, larval samples from each experimental tank were pooled, freeze dried and after acid hydrolysis, the quantification of amino acids was done by a reverse phase high performance liquid chromatography ( N = 2). The highest represented of the total amino acids were for glutamic acid and phenylalanine (with cystine) with ranges from 13.4–16.6 and 9.7–11.5%, respectively, whereas tryptophan (1.4–1.6%). methionine (1.4–2.7%) and histidine (2.9–4.2%) were relatively lower. The levels of the following essential amino acids did not significantly change during larval development: arginine, leucine, phenylalanine (plus cystine), threonine, tryptophan and valine. Despite statistically significant changes that were observed in levels of some amino acids, amino acid composition appeared to be relatively unchanged during the larval growth. The results may suggest that the amino acid requirements of the freshwater prawn is relatively constant during larval life and can be satistied by a suitable protein source that resembles the larval amino acid profile.