菠萝蜜种子淀粉制备香草兰微胶囊的工艺研究

以菠萝蜜种子淀粉为壁材,采用饱和水溶液法制备香草兰精油微胶囊,以包埋产率为指标,采用响应面分析法对微胶囊的包埋条件进行优化探讨。结果表明:5个单因素中,影响最显著的因素为壁芯材比例、包埋温度和包埋时间。响应面优化得到香草兰精油微胶囊的最佳工艺条件为壁芯材比例为7.5∶1;包埋时间72 min;包埋温度54℃,此条件下的包埋产率为(95.46±0.2)%,包埋率为(76.35±0.6)%,载油量为(27.73±0.3)%。试验证明,此条件结果与模型预测值相吻合,此工艺条件可为菠萝蜜种子淀粉包埋香草兰精油微胶囊工艺提供理论依据。     

不同贮藏年限老芒麦种胚线粒体抗氧化功能的变化规律

种子在自然贮藏过程中常常伴随着内部生理机能的恶化，线粒体作为种子内活性氧（reactive oxide species，ROS）产生的主要位点是最先遭到破坏的细胞器。为探讨不同贮藏年限对老芒麦种胚线粒体抗氧化功能的影响，本试验以室温贮藏0～4年的老芒麦种子为材料，分析比较其老化规律及种胚线粒体抗氧化特性的变化规律。结果表明：随着贮藏年限的延长，老芒麦种子发芽势、发芽率和种苗鲜重逐渐下降，死种子逐渐增多，种胚线粒体苹果酸脱氢酶（mitochondria malate dehydrogenase，MDH）、谷胱甘肽还原酶（glutathione reductase，GR）、单脱氢抗坏血酸还原酶（monodehydroascorbate reductase，MDHAR）活性逐渐下降，但在死种子中超氧化物歧化酶（superoxide dismutase，SOD）活性显著升高。此外，在贮藏过程中老芒麦种胚线粒体O₂^·-产生速率不断上升，而H₂O₂含量则呈现逐渐降低的趋势，表明线粒体中O₂^·-的积累与细胞氧化损伤密切相关。     

陕西关中东部灌区施用氮磷钾肥对夏玉米产量的影响

对陕西关中东部灌区夏玉米施用氮磷钾肥进行了研究,结果表明:施用氮磷钾肥能显著增加玉米产量,是夺取玉米高产的有效措施。氮磷钾肥对玉米产量和经济性状影响的顺序是:N>P>K。     

纳米技术在动物科技中的应用

纳米技术是20世纪90年代出现的一门新兴技术,由于纳米材料理化性质的奇特性,其将给动物科技与动物医学带来巨大的革命。本文就纳米技术在动物科技中的应用(如遗传育种,饲料开发,兽药研制、生产,动物疾病防疫与诊断等)作一概述。     

促性腺激素释放激素基因及其受体基因的研究进展

作者简要介绍了促性腺激素释放激素基因及其受体基因的位置、结构、表达、调控机理,并初步探讨了这两个基因与繁殖性能的关系。     

苏南丘陵区秋播苜蓿适用伴生作物筛选试验

为解决苏南丘陵区苜蓿苗期的杂草问题,从保护播种入手,在多年生黑麦草、一年生黑麦草、黑麦、小黑麦四种作物共五个品种中寻找适宜的伴生作物.通过对产量、株高、杂草率等多个指标测定分析,筛选出中新830小黑麦、赣选一号黑麦草适于用作苜蓿播种的伴生作物,同时获得两个苜蓿存活率最高的处理：苜蓿（15kg/hm^2）＋中新830小黑麦（150kg/hm^2）撒播及苜蓿（18 kg/hm^2）＋中新830小黑麦（250kg/hm^2）30cm条播.试验还表明撒播方式下,苜蓿播量与其竞争力不成正比。     

Changes of urinary albumin and N-acetyl-beta-glucosaminidase in high altitude polycythemia at different altitudes and its mechanism

AIM:To study the changes of excretive amount of albumin(ALB), N-acetyl-beta-D-glucosaminidase(NAG) in patients with high altitude polycythemia(HAPC) at different altitude and its mechanism.METHODS:Urinary ALB, NAG, activity of red blood cell superoxide dismutase(RBC-SOD), malonyldialdehyde(MDA) and erythrocyte filtration index(EFI) of 231 healthy subjects and 86 patients with HAPC at different altitude were detected.RESULTS:Excretive amount of urinary ALB, NAG, and plasma MDA, EFI were higher, and RBC-SOD was lower in patients with HAPC than those in healthy subjects, the changes were significantly obvious, with increasing altitude. Urinary ALB and NAG were negatively correlates to EFI, and no correlated to the content of MDA and RBC-SOD.CONCLUSIONS:EFI exertes an independent influence on urinary ALB and NAG. The decrease in erythrocyte deformability caused by the increase of peroxidation of lipids might participate in the pathogenesis and progress of the increase of excretive amount of ALB and NAG in HAPC.     

Selection and amplification of the liver stem cell subset from rat bone marrow cells with a medium containing cholestatic serum in vitro

AIM: To explore the feasibility of direct separat and selective enlargement of the bone marrow-derived liver stem cells (BDLSC) from bone marrow cells with a culture system containing cholestatic serum in vitro. METHODS: Bone marrow cells of rats were cultured with selective media containing 2%, 5%, 7% and 10% cholestatic rat serum, respectively. The BDLSC were then induced to proliferate with the addition of hepatocyte growth factor (HGF) on the firth day. BDLSC were characterized using immunocytochemistry and RT-PCR for lineage markers, glycogen staining and urea synthetic assay for functions 2 weeks later. RESULTS: Bone marrow cells were unble to form colony in the presence of 2% cholestatic serum and apopotosis appeared gradually in 7% or 10% cholestatic serum. The BDLSC survived in the medium containing 5% cholestatic serum while the other types of cells did not. The survival cells proliferated with a high speed during the second week and then formed hepatocyte-like colony-forming units (H-CFU). Cells in the H-CFU expressed the characteristic proteins of fetal hepatocytes. Furthermore, they had glycogen storage and urea synthesis functions, two of the critical features of hepatocytes. CONCLUSION: The selective micro-environment effectively selected BDLSC from the bone marrow cell, and will be a new way to provide an abundant source of donor hepatocytes for clinical cell therapy.     

Effect of mutant β-catenin gene on the proliferation of hepatocytes

AIM:The β-catenin is a key molecule in the Wnt signal pathway, which plays a critical role in normal development and tumorigenesis. However, the mechanisms of the β-catenin on the cell growth control are still not completely defined. The aim of this study was to test the hypothesis that the mutant β-catenin may regulate the hepatocyte proliferation. METHODS: The immortalized murine hepatocyte cell line, AML12, was used for this study. A plasmid that contain mutant β-catenin S33Y was transfected into the AML12 cells and a stable cell line AML12S33Y was established. The cell growth property of this cell line and the parental cell were compared by flow cytometry analysis and direct cell count. The cells were also tested for the ability to form soft agar colonies, and the ability to form tumors in the severe immune deficient mice (SCID). RESULTS:1. The mutant β-catenin containing cell line AML12S33Y has higher proliferating index compared with the parental AML12 cells (P<0.01), suggesting that mutant β-catenin promotes cell growth. 2. The mutant β-catenin cells formed small colonies in soft agar after 4 weeks of culture, but did not generate tumor in SCID mice. CONCLUSION:The mutant β-catenin promotes liver cell growth.