心土培肥犁改良瘠薄土壤的效果

研究根据心土培肥的改土技术要求研制出心土培肥犁,并分别在瘠薄黑土和碳酸盐草甸黑钙土上开展大面积机械改土试验,明确自主研发的心土培肥犁改土后对土壤理化性质影响及对作物产量的效果,为其广泛应用到低产土壤改良提供机械及技术支持。试验设深松、心土培肥和常规对照耕作,采用大田对比方法。研究结果表明:心土培肥和深松在不同类型土壤上对土壤理、化性质,对作物产量及产量性状影响后效不完全一致;心土培肥降低土壤抗剪强度后效明显,碳酸盐草甸黑钙土>10～30 cm土层土壤抗剪强度比对照降低6.65~12.16 kPa,黑土比对照降低8.20~11.31 kPa,碳酸盐草甸黑钙土改土后效果明显,黑土改土后效长,心土培肥改土效果优于深松;土壤容质量和硬度趋势同上;心土培肥提高土壤透气系数为2.78~14.28倍,饱和导水率为2.38~11.62倍;深松和心土培肥可提高下层土水分消耗比例,>30~60 cm土层耗水量为心土培肥区> 深松区>对照区,心土培肥耗水量比照高10%;心土培肥处理可提高土壤磷含量和供磷强度,>20～30 cm和>30~40 cm土层土壤供磷强度比对照分别提高4.19~5.17倍和4.96~17倍,碳酸盐草甸黑钙土高于黑土;心土培肥可提高玉米产量,碳酸盐草甸黑钙土上心土培肥增产幅度为6.82%~18.01%,黑土增产幅度为6.45%~11.18%,平均增产效果碳酸盐草甸黑钙土>薄层黑土,但黑土持续增产效果好。     

火麻籽多肽对高脂饮食喂养大鼠血脂的影响

目的：通过动物实验对火麻籽多肽进行降血脂功能性进行研究。方法：选取60 只SD雄性大鼠,适应性饲养1 周后,分成正常对照组（10 只）、模型组（50 只）,正常对照组给予基础饲料,模型组饲喂高脂饲料,连续饲喂4 周建立高血脂模型大鼠;造模成功后将模型组平均分为高脂模型组、阳性对照组（辛伐他汀,10 mg/kg mb）和火麻籽多肽低（200 mg/kg mb）、中（400 mg/kg mb）、高（800 mg/kg mb）剂量组,分别经口灌胃饲喂4 周后测定大鼠体质量,脏器指数,血清中总胆固醇（total cholesterol,TC）、甘油三酯（triglyceride,TG）、高密度脂蛋白胆固醇（high-density lipoprotein cholesterol,HDL-C）和低密度脂蛋白胆固醇（low-density lipoprotein cholesterol,LDL-C）、谷草转氨酶（aspartate aminotransferase,AST）、谷丙转氨酶（alanine aminotransferase,ALT）水平,血液流变学变化,肝脏病理切片组织形态学变化。结果表明：与高脂模型组相比,火麻籽多肽能够抑制大鼠的体质量增长,降低肝脏指数和血清中TC、TG、LDL-C、AST、ALT水平,升高HDL-C水平,降低动脉硬化指数,改善大鼠血流变学指标,降低大鼠的全血黏度和血浆黏度;改善肝脏脂肪变性情况。结论：火麻籽多肽对高脂饮食喂养大鼠具有一定的降脂作用。     

密度对大豆群体冠层微气象特征及产量的影响

以垦农4号大豆为试验材料,在大田条件下,研究了密度对大豆群体光合有效辐射强度、温度、相对湿度、CO2浓度、风速及产量的影响。结果表明：不同群体冠层的微气象特征存在差异,高密度与低密度群体之间差异显著。光合有效辐射强度及风速均随着密度的增加呈递减趋势。温度、湿度及CO2浓度具有明显的日变化规律,昼夜温差在14～17.3℃,群体的相对湿度正午12∶00时最低,高低密度群体湿度差相隔3%;群体间不同层次的CO2浓度越接近地面越高,从06∶00到12∶00时,密度为36万株/hm2的群体（即P2.4）各冠层CO2浓度均为最大。随种植密度增加,群体内单株荚数、粒数和粒重逐渐减少。当密度为36万株/hm^2时,群体产量最高。     

黑蒜加工过程中内生细菌的分离鉴定及其增效作用的研究

本文对黑蒜加工不同时期样品中的内生细菌进行分离鉴定,从中分离出1株芽孢杆菌,通过形态特征观察及16S r DNA序列测定对其进行鉴定,结果表明该菌为枯草芽孢杆菌,在大蒜汁培养基中生长时,具有生长旺盛、耐热性强、产黑色素的特点。将其回接到生蒜瓣上,50℃条件下48 h蒜瓣变为黑色,而未接种的蒜瓣则变为淡黄色,说明该菌液对大蒜由白蒜变为黑蒜有一定的贡献。这为研究黑蒜的形成机理提供了数据佐证,为进一步开发黑蒜发酵菌剂奠定了实验基础。      

Oxidative stress,NF-κB signaling,NLRP3 inflammasome,and caspase apoptotic pathways are activated in mammary gland of ketotic Holstein cows

Ketosis is a serious metabolic disorder characterized by systemic and hepatic oxidative stress, inflammation, and apoptosis, as well as reduced milk yield. Because of the paucity of data on mammary responses during ketosis, the aim of this study was to evaluate alterations in oxidative stress, NF-κB signaling, NLRP3 inflammasome, and caspase apoptotic pathways in mammary gland of dairy cows with ketosis. Blood, mammary gland tissue, and milk samples were collected from healthy cows [Control, blood concentration of β-hydroxybutyrate (BHB) <0.6 mM, n = 10] and cows with subclinical ketosis (SCK, blood concentration of BHB >1.2 mM and <3 mM, n = 10) or clinical ketosis (CK, blood concentration of BHB >3 mM, n = 10) at median 8 d in milk (range = 6–12). Compared with Control, serum concentration of glucose was lower (3.91 vs. 2.86 or 2.12 mM) in cows with SCK or CK, whereas concentrations of fatty acids (0.25 vs. 0.57 or 1.09 mM) and BHB (0.42 vs. 1.81 or 3.85 mM) were greater. Compared with Control, the percentage of milk fat was greater in cows with SCK or CK. In contrast, the percentage of milk protein was lower in cows with SCK or CK. We detected no differences in milk lactose content across groups. Compared with Control, activities of glutathione peroxidase, superoxide dismutase, and catalase were lower in mammary gland tissue of cows with SCK or CK. In contrast, concentrations of hydrogen peroxide and malondialdehyde were greater in cows with SCK or CK. Compared with Control, mRNA abundances of TNFA, IL6, and IL1B were greater in mammary tissues of cows with SCK or CK. In addition, activity of IKKβ and the ratio of phosphorylated inhibitor of κBα to IκBα, and of phosphorylated NF-κB p65 to NF-κB p65, were also greater in mammary tissues of cows with SCK or CK. Subclinical or clinical ketosis also led to greater activity of caspase 1 and protein abundance of caspase 1, NLRP3, Bax, caspase 3, and caspase 9. In contrast, abundance of the antiapoptotic protein was lower in SCK or CK cows. The data indicate that the mammary gland of SKC or CK cows undergoes severe oxidative stress, inflammation, and cell death.     

非精神活性药用大麻的应用及开发

为了实现大麻二酚酸合成酶（CBDAS）的微生物底盘高效表达,为体外合成大麻二酚（CBD）提供重组酶。首先从高CBD含量大麻叶片中克隆CBDAS基因,利用生物信息学方法分析其蛋白的基本理化性质,构建重组质粒pPIC9K-CBDAS后转化毕赤酵母菌,筛选重组蛋白CBDAS高表达的培养条件,并分析CBDAS的催化活性。结果表明,构建的pPIC9K-CBDAS融合蛋白表达系统能在毕赤酵母中表达;在甲醇添加量为1%、培养基pH6.0和培养48 h的诱导条件下表达量最大;重组酶CBDAS催化底物大麻萜酚酸（CBGA）反应4 h后大麻二酚酸（CBDA）含量显著增加（P<0.05）,在8 h后CBD含量显著增加（P<0.05）,在12 h时合成CBDA和CBD量达到最大值;CBDAS在大麻叶片大麻萜酚酸（CBGA）粗提液和CBGA标品中反应12 h后分别生成CBDA 60.64和20.12 ng/mL,CBD 128.01和207.87 ng/mL,具有较强的催化活性。通过酵母异源表达实现了大麻CBDAS的重组表达,为经济高效地合成CBDA和CBD提供活性酶。     

外源脱落酸处理对葡萄果实及葡萄酒中抗氧化成分的影响

以天津蓟州区栽培的"美乐"和"赤霞珠"葡萄为试验品种,分别在其始熟期的初、中和末期3个阶段利用外源脱落酸(200 mg/L)处理果实,采用分光光度法测定葡萄和葡萄酒中酚类总含量和抗氧化活性,利用液质联用技术分析花色苷的含量和组成.研究结果表明:始熟期的外源脱落酸处理对成熟果实的质量、可溶性固形物、可滴定酸和pH值,以及葡萄籽的酚类含量和抗氧化活性没有显著影响,但对葡萄皮和葡萄酒的酚类物质含量和活性具有显著影响.在始熟期中期(30％ ～50％果实转色)以前,对果实喷施外源脱落酸可以显著提高葡萄皮和葡萄酒的酚类总含量、花色苷总含量和抗氧化活性.始熟期外源脱落酸处理使"美乐"和"赤霞珠"果实的酚类总含量分别提高了14％ ～39％和73％ ～172％,花色苷总含量和抗氧化活性分别提高了18％ ～143％和88％ ～178％;外源脱落酸处理使葡萄酒的3个指标(酚类总含量、花色苷总含量和抗氧化活性)分别提高了17％ ～69％、18％ ～36％和21％ ～46％,而这些影响可以有效改善葡萄酒的感官品质和营养价值.外源脱落酸处理时期的精准控制可以提高酿酒葡萄及葡萄酒中酚类物质含量及抗氧化作用,进而提高葡萄酒品质和营养价值.     

Phenolic features and anthocyanin profiles in winemaking pomace and fresh berries of grapes with different pedigrees

Food Science and Biotechnology - The total contents and antioxidant activities of phenolic compounds as well as anthocyanin profiles were analyzed and compared in fresh berries and fermented pomace...