铵态氮素促进甘薯块根形成的解剖特征及其IbEXP1基因的表达

This study chose Shangshu 19 (S19) and Jixu 23 (J23) categorized by valid tuber root number per plant as analyzing varieties and arranged treatment combinations consisted of two nitrogen forms ammonium nitrogen (A_N) and amide nitrogen (X_N) integrated with two nitrogen rates 60 kg hm^-2 (L_N60) and 180 kg hm^-2 (H_N180), using field and pot trial assays, plus a check treatment received no nitrogen supply in order to make research on the anatomical observation on sweet potato tuber root differentiation and expression characteristics of IbEXP1 gene associated with tuber root formation in ammonia nitrogen in 2014 and 2015. Our results showed that the storage root yield of Shangshu 19 associated with more valid tuber root number per plant was significantly higher than Jixu 23 at harvest stage, which was significant difference compared with each other. In addition, nitrogen levels and nitrogen forms had significant interaction effects. The 60 kg hm^-2 ammonium nitrogen treatment in two sweet potato genotypes achieved the highest final storage root yield in field experiment and showed higher valid tuber root number per plant, which attributed to the younger tubers whose root diameter between 0.5 cm and 5.0 cm during the canopy closure period. It had been observed that 60 kg hm^-2 ammonium nitrogen treatment possessed the most vessels in the primary xylem bundle and the lignified parenchyma cells of the stele tissues in the pre-cambial period, followed with possessing high level expression of IbEXP1 gene, the biggest root diameter and stele diameter and the most number of primary and secondary xylem bundles in the course of primary cambium growth. As the vascular cambium was initiated, relative expression of IbEXP1 gene at 60 kg hm^-2ammonium nitrogen treatment and the degree of parenchyma cells lignification were intermediate between no nitrogen application and high nitrogen treatments, however, the diameter of root and stele and the ratio of them were highest, which achieved the perfect harmony in lignification and division of parenchyma cells in tuberization.     

In vitro effect of recombinant human tumor necrosis factor-alpha on canine neutrophil apoptosis

Neutrophils (polymorphonuclear leukocytes: PMNs) are essential for the host defense against various infections and are often injurious to the host, causing inflammatory diseases where tumor necrosis factor-alpha (TNF-alpha) is suggested to play an important role. Since an effect of TNF-alpha on canine PMN apoptosis has not been studied, canine PMNs were stimulated with recombinant human (rh)TNF-alpha in the present study to investigate the effect of TNF-alpha on canine PMN apoptosis. PMN apoptosis and function to produce ROS were assessed by flow cytometry. Delayed apoptosis was observed in the PMNs treated with rhTNF-alpha at 100 ng/ml, accompanied by retention of capability to produce ROS. However, PMN apoptosis was accelerated by rhTNF-alpha combined with cycloheximide. Therefore, it is indicated that TNF-alpha is able to activate anti- and pro-apoptotic pathways in PMNs and that the inhibition of PMN apoptosis by TNF-alpha requires protein synthesis in the PMNs.     

长期不同施肥对稻田土壤有机质和全氮的影响

通过对湖南新化、宁乡、株洲、桃江、武岗5个国家级稻田肥力长期定位试验点18年的田间定位试验,研究了不同施肥方式下0-20 cm土层土壤有机质和全N含量的演变规律。结果显示,中量和高量有机肥与化肥配合处理在提高土壤有机质和全N含量方面效果明显优于单施化肥和秸秆还田处理,且随有机肥用量的增加而增加,表明有机肥与化肥配合施用是提高土壤有机质和N素肥力的重要措施。在不同施肥方式下,稻田土壤有机质总体上呈现出上升或者下降的趋势,但在不同的年份会有波动。     

绿肥轮作还田对稻田土壤溶液氮素变化及水稻产量的影响

通过研究利用绿肥等改变轮作制度及N素管理后稻田土壤溶液中溶解性N素的动态变化及水稻产量的变化,评价了利用绿肥参与水稻轮作系统,减少无机N肥的施用量,促进水稻生长的同时降低环境负荷的可行性。研究表明,在总N量相当的情况下,冬绿肥还田或冬季休闲稻季土壤溶液中NH4 -N浓度均比稻麦轮作单施化肥的处理低。溶液NO3--N浓度随还田有机物料的C/N增加显著降低。利用豆科紫云英轮作还田,可降低44％的无机N肥用量,溶解性N浓度显著降低,是减小稻季N肥流失环境风险的有效途径。     

零价铁渗透反应格栅原位修复地下水中氯代烃的应用及研究进展

零价铁(Fe0)渗透反应格栅是一种简单廉价而有效的新型技术,可用来修复地下水中的氯代烃污染。Fe0渗透反应格栅有广阔的应用前景,但也有自身的一些缺点,仍需进一步研究改善。本文介绍了目前渗透反应格栅的安装结构及特点,并对Fe0渗透反应格栅的现场应用及研究进展情况进行了系统论述。     

稻草覆盖对坡地红壤培肥及作物增产的效果

研究了坡地红壤连续5年采用稻草覆盖措施对土壤肥力和作物产量的影响。结果表明,“稻草+化肥氮磷”(“Straw+NP”)处理的土壤有机碳和全氮、磷分别比不施肥(CK)的提高42.9%和17.4%、44.2%,有机碳和全氮的增幅约是纯化肥(NPK)处理的2倍。与CK和NPK处理的相比,“Straw+NP”处理能明显提高微生物生物量碳、氮、磷和溶解性有机碳、氮以及Olsen-P含量,差异达到显著(P<0.05)或极显著(P<0.01)水平。在等养分施用量的条件下,“Straw+NP”处理能显著提高油菜和甘薯的产量。因此,稻草易地覆盖是一种有效培肥坡地红壤和增加作物产量的途径。     

Effect of antioxidant supplementation on free radical scavenging system and immune response in lindane treated scabies patients

The scabicide, lindane induces oxidative stress and immunological alterations. The present study was undertaken to assess the ameliorative effects of antioxidant supplementation in lindane treated scabies patients. Scabies patients were treated with either 1% lindane or 1% lindane along with antioxidant (Lycored or Vitamin-E). Oxidative stress and immunological parameters were evaluated in blood samples and compared with healthy controls. Lindane caused a significant increase in malonedialdehyde (MDA) levels and decrease in reduced glutathione (GSH) and ferric reducing ability of plasma (FRAP), which was attenuated by anti-oxidant therapy. The IL-1α levels were significantly enhanced in scabies patients per se and remained unaffected after lindane/anti-oxidant treatment. The TNF-α and nitroblue tetrazolium (NBT) reduction levels were not significantly different in all the groups. Topical application of lindane induces significant free radical generation and may cause immunological alterations which can be reversed by antioxidant therapy.     

Antioxidant role of propolis extract against oxidative damage of testicular tissue induced by insecticide chlorpyrifos in rats

Pesticides induce oxidative stress leading to generate free radicals and alternate the antioxidant or oxygen free radical scavenging enzyme system. This study was conducted to investigate the oral toxicity of chlorpyrifos toward male rat and the oxidative stress of the sub-lethal dose (9 mg/kg; 1/25 LD₅₀) on the lipid peroxidation level (LPO), reduced glutathione content (GSH) and antioxidant enzymes; catalase (CAT), superoxide dismutase (SOD), glutathione peroxidase (GPx) and glutathione-S-transferase (GST) activities of testicular tissue. Also, the protective effects of propolis extract (50 mg/kg b.w.) alone or in combination with chlorpyrifos were investigated. The oral administration of chlorpyrifos significantly caused elevation in LPO level by 1.79-fold as compared to control. The activities of antioxidant enzymes including CAT, SOD, GPx and GST were decreased significantly (23.66%, 27.75%, 29.13% and 11.52%) as well as the level of GSH decreased by 21.97% in testicular tissue as compared to control animals. Co-administration of propolis extract with chlorpyrifos or alone in male rats decreased LPO level, normalized CAT, SOD GPx and GST activities, while GSH content was increased in testicular tissue. We conclude that propolis extract significantly reduces chlorpyrifos-induced oxidative stress in rat testis and the protective effect of the pre-treatment with propolis extract as attenuating agent could be due to its antioxidant properties.     

种植密度和氮用量对烟叶光合特性和产量质量的影响

在豫西半干旱地区洛宁采用密度和施氮量2因素裂区设计,研究了不同种植密度和氮用量对豫西地区烟叶光合有效辐射、光合特性和产量质量的影响.结果表明:(1)随着氮肥和密度的增加,烟株能截获更多的光合有效辐射.随着施氮量的增加烤烟净光合速率增加.高密度和高施肥量会导致烟叶气孔导度变小.(2)从烟叶产量上看,在相同的密度下,烟叶的产量随着施肥量的增加而增加,产量以D3N4处理最高,达3 162 kg/hm2;种植密度对烟叶产量的影响较大,在相同施肥水平下以D3密度平均产量最高,但D3与D2密度除N4施肥水平外产量差异不显著.从产值上分析,在相同施肥水平下以D2密度产值较高,D2N2和D2N4产值分别达到42 148.5元/hm2和42 454.5元/hm2,上等烟比例分别为32.2％和32.8％,烟叶均价以D2N2处理最高,达14.9元/kg.(3)综合分析,在豫西烟区,种植密度以D2密度(16 500株/hm2),氮肥施用量以N2水平(60 kg/hm2)为宜.     

外源NO对渗透胁迫下黑麦草种子萌发及活性氧代谢的影响

以黑麦草为试材,研究了一氧化氮(NO)供体硝普钠(SNP)对聚乙二醇6000渗透胁迫下种子萌发、幼苗叶片活性氧代谢和渗透溶质积累的影响,探讨外源NO对渗透胁迫下牧草生理响应的调节作用.结果表明:100μmol/L SNP显著提高了渗透胁迫下黑麦草种子的发芽率、发芽指数和活力指数,缓解了植株鲜重和干重的下降幅度,提高了幼苗叶片SOD、POD、APX、质膜H+-ATPase活性及谷胱甘肽、可溶性糖、游离氨基酸、脯氨酸、K+、Na+含量和植株含水量,降低了O2-.产生速率及H2O2、丙二醛和可溶性蛋白含量.表明外源NO能够促进渗透胁迫下黑麦草种子的萌发,对渗透胁迫引起的黑麦草幼苗膜脂过氧化具有缓解作用.