Quinoa (Chenopodium quinoa Willd.) protein hydrolysates with in vitro dipeptidyl peptidase IV (DPP-IV) inhibitory and antioxidant properties

The potential of quinoa to act as a source of dipeptidyl peptidase IV (DPP-IV) inhibitory and antioxidant peptides was studied. A quinoa protein isolate (QPI) with a purity of 40.73 ± 0.90% was prepared. The QPI was hydrolysed at 50 °C for 3 h with two enzyme preparations: papain (P) and a microbial papain-like enzyme (PL) to yield quinoa protein hydrolysates (QPHs). The hydrolysates were evaluated for their DPP-IV inhibitory and oxygen radical absorbance capacity (ORAC) activities. Protein hydrolysis was observed in the QPI control, possibly due to the activity of quinoa endogenous proteinases. The QPI control had significantly higher DPP-IV half maximal inhibitory concentrations (IC₅₀) and lower ORAC values than QPH-P and QPH-PL (P < 0.05). Both QPH-P and QPH-PL had similar DPP-IV IC₅₀ and ORAC values. QPH-P had a DPP-IV IC₅₀ value of 0.88 ± 0.05 mg mL⁻¹ and an ORAC activity of 501.60 ± 77.34 μmol Trolox equivalent (T.E.) g⁻¹. To our understanding, this is the first study demonstrating the in vitro DPP-IV inhibitory properties of quinoa protein hydrolysates. QPHs may have potential as functional ingredients with serum glucose lowering properties.     

穿琥宁注射液对大鼠的长期毒性试验

将SD大鼠随机分为4个组,3个剂量组分别按75.7、15.14、7.57mg/kg通过腹腔注射法对大鼠给药,对照组给予同体积生理盐水,连续观察28d,记录大鼠毒副反应情况。停药后继续观察2周,测试大鼠体重、血液学指标、血液生化学指标、脏器指数。结果表明,各剂量组大鼠与对照组比较,给药期与恢复期的体重增长、血液学指标、血清生化指标、脏器指数均无显著性差异(P0.05)。试验结果表明,穿琥宁注射液连续给药28d,大鼠无不良反应,停药14d后亦未出现迟发性不良反应。     

Modification of protein structure and dough rheological properties of wheat flour through superheated steam treatment

Native (NF, 13.5% w.b) and moistened (MF, 27% w.b) wheat flours were treated with superheated steam (SS) at 170 °C for 1, 2 and 4 min, and their protein structure as well as dough rheological properties were analyzed. Confocal laser scanning microscopy (CLSM) and SDS-PAGE patterns indicated the formation of protein aggregates with reduced SDS extractability after treatment. Farinograph and dynamic rheometry measurements showed that the strength as well as elastic and viscous moduli of the dough made from SS-treated flours progressively increased with SS treatment time. And both the improvements were more pronounced for superheated steam-treated moistened flours (SS-MF) than for superheated steam-treated native flours (SS-NF). Size-exclusion high performance liquid chromatography (SE-HPLC) analysis demonstrated that dough rheological parameters have positive correlations with SDS unextractable polymeric proteins (UPP) contents. SS treatment on flours led to a transition of protein secondary structures to more ordered form (α-helix and β-sheet). Additionally, free sulfhydryl (SH) contents decreased after treatment, which implied that disulfide bonds accounted for protein extractability loss and dough rheological properties improvement. Elevated moisture level promoted the modification of both protein structure and dough behaviors of flours during SS treatment.     

绿洲水土资源协调开发的SD模型：以哈密为例

本文以节水措施的实施、供需水系统的完善和农业结构的调整为前提,通过对哈密市水资源系统、供需各要素的相互关系及其所隐含的反馈信息的考察,建立了哈密市水土资源协调开发的SD模型。通过模型求解,得出了哈密市在一定水资源利用状况下的土地开发规模,并确立了与之相适应的耗水结构及作物种植结构。     

维生素D受体在体外培养SD大鼠脂肪细胞中的表达

为了探索维生素D受体(VDR)在SD大鼠脂肪细胞分化过程中的表达规律,采用Ⅱ型胶原酶消化法进行SD大鼠脂肪细胞的分离培养,并将其诱导分化为成熟的脂肪细胞,分别在细胞生长至单层汇合后的第0、4、8、12、16天收集细胞样品。对VDR和脂滴进行荧光染色,同时采用Western blot对脂肪细胞分化过程中的VDR蛋白表达量进行分析,采用real-time PCR定量分析脂肪细胞分化过程中的VDR表达量。结果显示,随SD大鼠脂肪细胞的分化,细胞中脂滴逐渐增加,VDR mRNA和蛋白的表达量与脂质积累过程呈负相关性,表明VDR的表达在脂肪细胞分化过程中有一定的变化规律,其可能以负反馈的调节机制参与了脂肪细胞的分化过程。     

短期灌喂民猪源贝莱斯芽孢杆菌M2对SD大鼠生长、免疫及肠道菌群的影响

试验探究了短期灌喂民猪源贝莱斯芽孢杆菌M2对SD大鼠生长、血液生化与免疫、肠道菌群等相关指标的影响，拟为贝莱斯芽孢杆菌在畜禽中的应用提供参考依据。选取21日龄、体重相近、SPF级健康SD雌性大鼠共24只，将其随机分成2组，每组6个重复，每个重复2只。预饲期3 d。试验期，对照组灌喂生理盐水0.2 mL/d，试验组灌喂猪源贝莱斯芽孢杆菌M2菌液0.2 mL/d；每天灌喂1次，连续灌喂7 d。35和45日龄，每个重复随机选取1只大鼠处死采样。结果表明，短期灌喂贝莱斯芽孢杆菌M2有增加末重和日增重、降低日采食量和料重比的趋势（P>0.05）。短期灌喂贝莱斯芽孢杆菌M2显著降低了35日龄大鼠血浆中甘油三酯浓度和IgA、TNF-α的水平（P<0.05），以及45日龄大鼠血浆中IL-6的浓度（P<0.05），并显著提高35日龄大鼠血浆中IgM的浓度（P<0.05）；对35日龄大鼠肠道菌群无显著影响（P>0.05），可显著降低45日龄大鼠放线菌门和变形菌门的比例（P<0.05）。综上所述，短期灌喂贝莱斯芽孢杆菌M2可以调控SD大鼠的脂代谢、免疫力和肠道多种菌群的丰度。     

基于SD量表的农机产品色彩感性体验研究

采用SD量表法,获取和描述主体对大型农机产品主体色彩的感性体验,并对色彩的感性描述进行因子分析,提取农机产品色彩体验的两个公因子;将两个公因子作为坐标轴绘制农机色彩的意象分布图,对其感性体验做出规律性的描述;最后,通过对比测试,验证实际环境背景是否影响农机色彩感性体验。     

手持式农业环境温度检测仪的设计

温度是生物生存的重要环境因素之一,各种动植物生长、发育及繁殖都要求在一定的温度范围内进行。为实现对农业环境温度因子的精确测量、数据的实时获取与处理分析,设计了一种适于农业生产的便捷式环境温度检测仪。它以STC12LE5A60S2单片机为核心,采用DS18B20温度传感器进行数据采集,可实现对农业环境温度的快速精确测量,支持实时、历史数据读取以及SD卡数据存储功能。实验运行表明,该仪器可快速、精确地测量农业环境温度,具有实时数据采集、历史数据读取以及数据存储功能。     

苦马豆素诱导新生SD大鼠大脑皮质神经细胞凋亡

为阐明苦马豆素（SW）对新生SD大鼠大脑皮质神经细胞凋亡的影响,利用新生SD大鼠大脑皮质神经细胞体外原代培养模型,采用倒置相差显微镜、扫描电子显微镜及荧光显微镜观察sw对神经细胞的形态学损伤,运用流式细胞仪检测神经细胞凋亡率。结果显示,与对照组比较,各试验组神经细胞密度降低,神经网络减少且部分断裂;细胞表面粗糙,可见大量突起的小泡;细胞核出现浓缩、碎裂及新月形变化;随攻毒剂量的增加,神经细胞凋亡率呈明显上升趋势,与对照组相比,差异显著（P〈0．05）。结果表明,Sw能诱导新生sD大鼠大脑皮质神经细胞发生凋亡,这可能是Sw导致动物神经毒性损伤的作用机制之一。     

陕西关中地区水资源-社会经济系统时空协同分析

以系统动力学模型为依据,根据渭河流域生产系统、生活系统和水资源系统相互作用机理,在满足一定程度的河道生态环境用水的情况下,建立关中地区社会经济发展与水资源关系模型;根据不同的发展目标和政策条件,分别运行高速发展方案(HD)、协调发展方案(CD)和调水发展方案(MD)。认为MD方案是实现关中地区水资源与社会经济系统协调发展的最佳途径;现有(含规划)的引水工程的数量不能完全满足未来社会经济发展的要求,应规划建设新的引水工程,并需要提前完工投入使用。