3种农药对烤烟旺长期叶绿素含量及相关酶活性的影响

为了研究大田中常用3种化学农药对烤烟旺长期生理活性的影响,选用3种不同农药(氧化乐果乳油、乙酰甲胺磷乳油、吡虫啉可湿性粉剂),测定其在烟苗旺长期对烤烟叶片的叶绿素含量和吲哚乙酸氧化酶(IAAO)、硝酸还原酶(NR)、转化酶(InV)、苯丙氨酸解氨酶(PAL)、多酚氧化酶(PPO)等5种酶活性的影响。结果表明,喷施3种农药均不同程度地降低了叶片中叶绿素含量、NR和InV活性,并随着烟草生育期的推进,上述指标均有所提高;而IAAO,PAL和PPO活性在施药后明显增加,随着烟草生育期的推进回落明显。这3种农药对烟草叶片中不同的生理活性指标有着不同程度的影响。     

碱性过氧化氢预处理糠醛渣超声波辅助酶解研究

以糠醛渣为原料进行碱性过氧化氢法预处理,采用超声波辅助酶解法,比较分析不同模式下的葡萄糖转化率及水解液残存酶活。研究结果表明:酶解2 h时辅以超声波是糖转化的最佳条件,超声波辅助酶解及分段加酶使糖产率由55.01%提高到73.35%。超声波的机械作用影响着酶的吸附与脱附,有利于其与底物的充分结合。不同超声波酶解模式对糖产率的影响较大,且U-C模式效果较好,使糖产率提高46.35%。同时,酶解前超声波可以使糖产率提高33.34%。可见,低能耗,低污染的碱性过氧化氢预处理糠醛渣超声波辅助酶解为工业化生产乙醇提供了良好的发展方向。     

The effect of Astragaloside IV on immune function of regulatory T cell mediated by high mobility group box 1 protein in vitro

High mobility group box 1 protein (HMGB1), a potent pro-inflammatory cytokine, contributes to the pathogenesis of diverse inflammatory and infectious disorders. Some studies have illustrated the potential effect of HMGB1 on regulatory T cells (Tregs). Astragaloside IV (AST IV) isolated from a Chinese herb, Astragalus mongholicus, is known to have a variety of immunomodulatory activities. However, it is not yet clear whether AST IV possesses potential regulatory effect on the pro-inflammatory ability of HMGB1 with subsequent activation of Tregs. This study was carried out to investigate the antagonistic effects of different doses of AST IV on the immune function of Tregs mediated by HMGB1 in vitro. Tregs isolated from the spleens of mice were co-cultured with HMGB1 and/or AST IV. Cell phenotypes of Tregs were analyzed, and the contents of various cytokines in the cell supernatants as a result of co-culture and the proliferation of CD4⁺CD25⁻ T cells were determined. Results showed that HMGB1 stimulation resulted in significantly down-regulation of expressions of Tregs cell phenotypes. However, AST IV can rival the suppressing effect of HMGB1 on immune function of Tregs with a dose-dependent in vitro. These results indicate that AST IV has the potential therapeutic action on inflammation augmented by HMGB1.     

屯昌县发展海南珍贵乡土树种的建议

通过对屯昌县在"绿化宝岛"行动中因地制宜发展和利用珍贵乡土树种的情况的调研,分析了在"绿化宝岛"行动中因地制宜发展和利用珍贵乡土树种中存在的问题,提出了解决的对策。     

林麝养殖中活体取香的方法及步骤

人工养殖林麝活体取香是有效保护林麝野生资源的重要途径。陕西凤县有着悠久的林麝人工养殖历史,在实践经验基础上,就人工养殖林麝活体取香的时间、工具、取香技术与操作方法步骤等方面进行了总结与阐述。     

现代奶牛场技术管理体系的建立与探讨

本文分析和总结了当前我国奶牛养殖业中普遍存在的问题和弊端,提出了"三关一过程"即饲料入口关、繁殖配种关、牛奶产出关和奶牛场饲养管理全过程的监管控制体系,实践证明这是一套行之有效的奶牛场技术管理体系.     

Ileal and total tract digestibility in local (Mong Cai) and exotic (Landrace × Yorkshire) piglets fed low and high-fibre diets, with or without enzyme supplementation

Ileal and total tract digestibility of low and high-fibre diets (100 and 200 g/kg neutral detergent fibre), with or without enzyme supplementation (mixture of cellulase, β-glucanase, α-amylase and protease) was determined in piglets of two breeds weaned at 30 days of age. The breeds were local (pure-breed Mong Cai, MC) and exotic (Landrace × Yorkshire, LY). The experimental diets were based on maize meal, soybean meal, fish meal, cassava residue meal, and rice bran. Cassava residue meal and rice bran were the main fibrous feeds in the high-fibre diet. The experiment was arranged according to a 2 × 2 × 2 factorial, completely randomized design with 4 replications, and lasted for 30 days. The coefficient of ileal apparent digestibility (CIAD) was measured by analyzing ileal digesta collected from piglets killed at 60 days of age. The coefficient of total tract apparent digestibility (CTTAD) was measured by analyzing faecal samples collected for 5 consecutive days immediately before the experiment finished. The CIAD and CTTAD of organic matter, crude protein, crude fibre, neutral detergent fibre, acid detergent fibre and amino acids in the high-fibre diet were lower than in the low-fibre diet (P < 0.01). The CIAD of nutrients and amino acids was similar (P > 0.05) between MC and LY, while the CTTAD of nutrients was higher for the MC than for LY (P < 0.05). Enzyme supplementation of the high-fibre diet improved daily gain and the digestibility of all dietary components at the ileum and in the total tract (P < 0.05), but there was no effect of enzyme supplementation of the low-fibre diet (P > 0.05).     

FACE 条件下休闲和秸秆还田对稻麦轮作农田麦季土壤酶活性的影响

利用中国唯一的江都FACE(Free-airCO2 enrichment,开放式空气CO2浓度升高)平台,研究了大气CO2浓度升高下休闲(fallow,不种作物,但翻耕和施肥与其他处理相同)和秸秆还田对土壤脱氢酶、β-葡萄糖苷酶、转化酶、芳基硫酸酯酶和荧光素二乙酸酯水解(FDA)的影响。研究结果表明:大气CO2浓度升高对于休闲土壤酶活性没有影响。在没有秸秆还田的情况下,大气CO2浓度升高刺激了土壤中脱氢酶、β-葡萄糖苷酶、转化酶、芳基硫酸酯酶的活性和FDA水解,增加幅度分别达到了14.88%、19.41%、11.69%、17.12%和4.47%。除转化酶外,秸秆还田使土壤酶活性增加。随着秸秆还田量的增加,FACE效应先增加后消失。     

保护性耕作对土壤微生物特性和酶活性的影响

保护性耕作是以秸秆覆盖地表、免少耕播种、深松及病虫草害综合控制为主要内容的现代耕作技术体系。大力提倡和推行保护性耕作,对提高土壤质量和改善生态环境具有重要意义。本文回顾了保护性耕作的发展历程,概括和分析了保护性耕作对土壤微生物活性和垂直分布、微生物群落结构以及土壤酶活性的影响,也探讨了保护性耕作的发展前景。     

抗线虫基因番茄秸秆对土壤生物活性的影响

采用室内模拟培养的方法,研究了不同用量(2%,4%)转抗线虫基因番茄秸秆和普通番茄秸秆分解对土壤酶活性及微生物量碳的影响。结果表明:与普通番茄秸秆相比,添加低量(2%)秸秆,23d前,抗线虫处理土壤脲酶活性显著提高,9d时土壤碱性磷酸酶活性显著提高,23d时则显著降低,23d后,土壤微生物量碳含量显著提高。添加高量(4%)秸秆,4d时抗线虫处理土壤脲酶活性显著提高,91d时则显著降低,9d时,土壤碱性磷酸酶活性显著提高,23d,42d时则显著降低,9d,23d时,抗线虫处理土壤微生物量碳含量显著提高。抗线虫处理与普通处理间土壤蔗糖酶活性的差异在秸秆添加量为2%和4%时都不显著。