Changes of urinary exosomal leucine aminopeptidase and dipeptidyl peptidase 4 in diabetic nephropathy

AIM: To investigate the changes of urinary exosomal enzymes and the correlation with diabetic nephropathy.METHODS: Thirty-four healthy volunteers and 127 patients of type 2 diabetes mellitus (T2DM) were included in the study. The healthy volunteers served as control. The patients with T2DM were divided into 3 groups based on their 24 h urinary albumin/creatinine ratio (UACR): 50 patients with microalbuminuria in early DN group (DN1), 34 patients with macroalbuminuria in overt DN group (DN2) and 43 patients without albuminuria in DM group. The levels of urine exosomal leucine aminopeptidase(exosome-LAP) and exosomal dipeptidyl peptidase 4(exosome-DPP4) were determined by enzyme-linked immunosorbent assay (ELISA). The following methods were used to determine the biochemical parameters: liquid chromatography for glycated hemoglobin (HbA1c), chemical modification method for cholesterol (CH), Jaffe-kinetic assay for creatinine (CR) and urease-GLDH method for blood urea nitrogen (BUN). Multiple stepwise linear regressions were used to analyze the relationship of exosome-LAP or exosome-DPP4 with HbA1c, CH, UACR, CR and BUN. RESULTS: The levels of exosome-LAP and exosome-DPP4 in DM, DN1 and DN2 groups were significantly higher than those in control group (P<0.01). The exosome-LAP in DN2 group was significantly higher than that in DM group. Correlation analysis showed that the levels of urinary exosome-LAP and exosome-DPP4 were positively correlated with HbA1c, CH, UACR, CR and BUN. Multiple stepwise linear regression analysis showed that CH and UACR were independent determinants for exosome-LAP (P<0.01), and UACR and HbA1c were independent determinants for exosome-DPP4 (P<0.01). CONCLUSION: Urine exosome-LAP and exosome-DPP4 are correlated with the severity of diabetic nephropathy. These parameters may serve as clinical markers for the diagnosis and prognosis evaluation of diabetic nephropathy.     

江西峡江成功引种早熟青花菜中青8 号

近年来,江西省峡江县青花菜生产发展较快,年生产面积逾33.3 hm 2,主栽品种为优秀,一般每667m 2 产量950 kg 左右,产值4 000～4 500 元。为提高青花菜产量,增加农民收入,2009 年笔者从中国农业科学院蔬菜花卉研究所引进早熟青花菜品种中青8 号进行试种,试种面积10.13 hm 2,其中秋栽面积7.20 hm 2,每667 m 2 产量为1 126～1 183 kg,产值为4 640～6 110元;春栽面积2.93 hm 2,每667 m 2 产量936～964 kg,产值4 773～5 013 元。中青8 号比优秀平均每667 m 2 增加产量100～150 kg,增加产值800～1 000 元。与优秀相比,中青8 号株型更紧凑,叶片宽大,茎粗大,花球大,田间保持性好,市场价格高,但生育期迟2～3 d（天）。目前,中青8 号已是峡江县青花菜主栽品种,年栽培面积逾13.3 hm 2。     

蔗叶机械化粉碎还田对土壤效应的研究进展

蔗叶机械化粉碎还田技术的推广应用,在促进甘蔗以地养地、增加土壤有机质含量、改善土壤结构、培肥地力、提高甘蔗产量和品质走出了一条新路子.通过综述国内外蔗叶粉碎还田后对农艺性状、土壤肥力、土壤养分、土壤理化性状、甘蔗产量等方面的影响,分析蔗叶粉碎还田存在的主要问题,进一步探讨蔗叶机械化粉碎还田技术对抗旱保墒、化肥用量和生产成本等方面发展的应对措施.     

Isolation and characterization of a novel tannase from a metagenomic library

A novel gene (designated as tan410) encoding tannase was isolated from a cotton field metagenomic library by functional screening. Sequence analysis revealed that tan410 encoded a protein of 521 amino acids. SDS-PAGE and gel filtration chromatography analysis of purified tannase suggested that Tan410 was a monomeric enzyme with a molecular mass of 55 kDa. The optimum temperature and pH of Tan410 were 30 °C and 6.4. The activity was enhanced by addition of Ca(2+), Mg(2+) and Cd(2+). In addition, Tan410 was stable in the presence of 4 M NaCl. Chlorogenic acid, rosmarinic acid, ethyl ferulate, tannic acid, epicatechin gallate and epigallocathchin gallate were efficiently hydrolyzed by recombinant tannase. All of these excellent properties make Tan410 an interesting enzyme for biotechnological application.     

滴灌下不同供磷方式对马铃薯生长的影响

通过盆栽试验,研究了在滴灌施肥条件下不同供磷方式对马铃薯生长、产量、品质的影响。结果表明,施磷处理马铃薯的生物学产量显著高于不施磷处理,而不同供磷方式对马铃薯生物学产量的差异不显著;滴施磷肥处理有利于提高马铃薯块茎中的磷质量浓度;马铃薯块茎产量以50%磷肥基施、50%磷肥分10次追施的处理最高,且其商品薯率也最高,达到88.96%,比不施磷肥的对照处理高出6.54%;不同供磷方式对马铃薯块茎中的淀粉含量、干物质含量等品质指标的影响表现为差异不显著。     

高温厌氧环境中一株嗜热产甲烷古菌的分离鉴定

本研究采用Hungate厌氧操作技术、液体培养基和固体培养基交替传代的培养方法,从油层采出液中分离到一株产甲烷古菌DH-5.实验结果表明菌株DH-5为严格厌氧菌,菌体大小为(0.06～0.07)μm×(3.8～8.7)μm,可利用H2/CO2,但不利用其它供试底物;最适生长温度63℃;最适盐浓度0.80 g· L-1;最适pH为7.2;酵母粉为其生长必须因子;最适生长条件下其倍增时间为2.77 h.菌株DH-5与标准株Methanothermobaaer thermautotrophicus DSM 1053T (AY 196660)的16S rRNA基因序列相似性为99.8％.     

氧化塘深度对猪场厌氧消化液后处理的影响

采用小试装置对3个不同深度氧化塘处理猪场厌氧消化液的效果进行了研究,结果表明:当平均气温为21.9℃,停留时间在80 ～110天,进水负荷为0.05 m3·m-2d-1的条件下,氧化塘对NH4-N的去除率达到了90％以上,CODcr,TP的去除率分别为50％,40％.硝化作用和藻类的吸收是氧化塘去除NH4-N的主要方式,沉淀作用则是CODcr和TP的主要去除方式,在较长停留时间下,微生物对于溶解性CODcr的分解和同化也能提供一定的去除效果.当平均气温为21.9℃,在表面负荷为0.05 m3·m-2d-1的条件下,有效深度为0.3m和0.7m的氧化塘面积去除负荷分别为1.41 g·m-2d-1,1.49 g·m-2d-1,容积去除负荷分别为4.7g·m -3d-1,2.8g·m-3d-1.虽然较深氧化塘具有较高的面积去除负荷,但较浅的氧化塘却有更高的容积去除负荷.     

沼气发酵过程中产甲烷菌快速计数方法的研究

文章采用MPN以及显微计数两种方法对不同样品中甲烷菌数目进行检测.试验结果表明:显微计数用于沼气发酵过程中的甲烷菌检测是可行的.该法比MPN计数更加快速简便,结果也更接近真实情况.     

两种不同布水方式对生物砂滤池去除厌氧消化液氨氮的影响

在实验室条件下,采用试验生物砂滤柱模拟生物砂滤池系统,研究了雾化和滴渗布水方式对生物砂滤池去除猪场厌氧消化液氨氮的影响,结果表明:在进水水力负荷为0.057 m3.m-2d-1,氨氮平均浓度分别为293 mg.L-1,513 mg.L-1,553 mg.L-1时,雾化布水生物砂滤池对氨氮的平均去除率分别为98.8%,87.4%,75.1%,出水氨氮平均浓度分别为3.61 mg.L-1,64.7 mg.L-1,138 mg.L-1,平均去除负荷分别为16.4 g.m-2d-1,25.4g.m-2d-1,23.5 g.m-2d-1;滴渗布水生物砂滤池对氨氮的平均去除率分别为77.4%,71.4%,59.3%,出水氨氮平均浓度分别为66.3 mg.L-1,147 mg.L-1,225 mg.L-1,平均去除负荷分别为12.9 g.m-2d-1,20.7 g.m-2d-1,18.6 g.m-2d-1;雾化布水可以提高生物砂滤池氨氮的去除率、去除负荷,降低出水氨氮浓度;滴渗布水在进水氨氮平均浓度293 mg.L-1,雾化布水进水氨氮平均浓度293 mg.L-1,513 mg.L-1的条件下,出水氨氮平均浓度可达到《畜禽...     

乳清分离蛋白—多糖乳状液制备与乳化稳定性研究

在pH值7.0时以乳清分离蛋白为乳化剂制备初级乳状液,利用静电自组装技术,通过加入具有不同电性的阴离子型果胶、中性瓜尔豆胶、阳离子型壳聚糖制备具有良好稳定性的乳清分离蛋白-多糖的二级乳状液,并考察pH值、乳清分离蛋白与多糖的比例对乳状液稳定性的影响.结果表明:瓜尔豆胶与乳清蛋白乳状液粒子间无静电作用;在pH值5.0 ～6.0条件下,壳聚糖能够吸附到乳状液粒子表面,但形成的乳状液稳定性较差;在pH值3.0～5.0、果胶质量分数为0.2％～0.5％条件下,乳清分离蛋白-果胶为乳化界面构建的二级乳状液,稳定性最高.