长江中下游地区不同避涝作物种植模式对农田温室气体排放的影响

通过田间原位试验,研究长江中下游地区不同避涝作物种植模式对农田温室气体排放的影响,为该地区低碳作物种植模式的选择提供依据。利用静态箱法研究水稻-小麦(WRR)、黄心乌-茭白(WZR)、黄心乌-毛豆-荸荠(WECR)、水芹-芹芽-水稻(CCRR)和莲藕(LR)种植模式下农田的N₂O、CO₂和CH₄等温室气体的排放规律。结果表明：N₂O、CO₂和CH₄的排放具有明显的季节性,CO₂排放呈现夏季＞秋季＞春季＞冬季,CH₄和N₂O排放呈现夏季＞秋季;WECR、WRR和CCRR种植模式土壤CO₂排放量差异不显著,但都显著高于WZR,LR模式;WRR、CCRR和LR种植模式土壤N₂O排放量极显著高于WZR和WECR模式;LR极显著高于CCRR种植模式土壤CH₄排放量,而WZR、WECR和WRR极显著低于LR和CCRR。不同种植模式综合温室效应大小WRR＞CCRR＞WECR＞LR＞WZR,可见黄心乌-茭白模式综合温室效应最低,是长江中下游易涝区域低碳农业的较佳生产模式。     

植原体基因组学研究进展

植原体（phytoplasma）是一类重要的植物病原细菌, 可经叶蝉、飞虱等昆虫介体传播, 感染1 000多种植物, 产生丛枝、黄化、韧皮部黑斑坏死等症状, 给农业、林业生产带来巨大的损失。本文对植原体基因组学研究的历史、现状及当前植原体效应蛋白等方面的研究进展进行了综述。     

福建省鸡源大肠杆菌的分离鉴定及药敏试验

为探究福建地区鸡致病性大肠杆菌分离株的耐药情况。通过采集疑似大肠杆病死鸡的肝、脾、肺等脏器病料,并结合流行病学、临床学、病理学、生物化学和实验室PCR方法进行分离与鉴定,最终确诊为鸡大肠杆菌病。挑选分离的12株鸡大肠杆菌进行药敏试验,明确大肠杆菌耐药谱,为筛选敏感药物用于治疗与预防该病提供参考。     

红三叶提取物中总异黄酮含量测定的研究

为建立一种检测红三叶提取物中总异黄酮含量的快速分析方法,试验采用紫外分光光度法,以鹰嘴豆芽素A为标准品,在其紫外最大吸收峰260nm处测定提取液中总异黄酮的含量。稳定性试验、重复性试验、精密度试验、加标回收率试验的相对标准偏差分别为0.545%、0.915%、1.722%和1.550%,平均加标回收率为99.92%。结果表明,试验方法具有简便、快速、准确和重现性好等特点。     

Transmission of Leishmania infantum via blood transfusion in dogs: potential for infection and importance of clinical factors

Blood transfusion is an important routine practice in veterinary medicine that generally involves the use of whole blood. Permanent blood donors must be vaccinated against viral infections that affect dogs and submitted periodically to clinical and serological examinations to detect blood-transmitted diseases. There is a very high risk of transmission of infectious agents, particularly protozoans due to their long incubation periods, subclinical persistence in infected animals and likelihood of remaining viable in bloodstocks. The aim of the present study was to identify the potential of asymptomatic and oligosymptomatic dogs for Leishmania infantum transmission as a result of transfusional practice. Nineteen Leishmania-seropositive adult dogs of both sexes and indeterminate breeds were selected as donors. The animals were classified as symptomatic, oligosymptomatic or asymptomatic after clinical examination and evaluated by ELISA, IFAT and bone marrow puncture biopsies. Whole blood and monocyte cells were collected and used for dog's serological evaluation and inoculation in culture medium as well as in hamsters. All but three dogs were positive for IFAT, ELISA and parasite demonstration in bone marrow aspirates, irrespective of their clinical conditions. Parasites were detected in 77% of the whole blood and 90% of the monocyte cultures. Six months after inoculation with whole blood or monocytes, hamsters developed infection and clinical symptoms of visceral leishmaniasis, as well as positive titres measured by ELISA. These results suggest that blood donors should be monitored periodically and rigorously for Leishmania infection, to prevent dissemination of the disease through blood transfusion.     

精准营销在种业中的应用

首先阐述了精准营销的概念,并将其引入传统农业科技含量较高的种子产业当中.其次,介绍了中国种业的营销现状和面临的问题,提出了精准营销在种业中的具体应用.最后.通过利用信息化手段,结合精准营销方法实现种业企业的低成本扩张.同时,也实现了高效营销理论方法和传统产业营销结合的集成创新.     

提高高校院级教学质量的探讨

教育质量是高等教育的生命线,科学决定人才培养方案,加强师资队伍建设,构建以教学质量为核心的教学管理模式及改进和完善教学质量监控体系是提高教学质量的重要举措.     

北京市农业野生植物资源普查与研究

通过2003-2007年的普查,首次查明了北京市农业野生植物种类和分布现状。普查结果表明,北京市农业野生植物有1084种,其中国家级农业野生保护植物1种;国家级野生药用植物13种;新记录野生植物54种;外来入侵植物76种;珍稀濒危植物93种,为北京市编制重点保护野生植物名录,开展野生植物保护和可持续开发利用野生植物资源提供了科学依据。     

Anti-melanogenic property of geoditin A in murine B16 melanoma cells

Geoditin A, an isomalabaricane triterpene isolated from marine sponge Geodia japonica, has been demonstrated to induce apoptosis in leukemia HL60 cells and human colon HT29 cancer cells through an oxidative stress, a process also interfering with normal melanogenesis in pigment cells. Treatment of murine melanoma B16 cells with geoditin A decreased expression of melanogenic proteins and cell melanogenesis which was aggravated with adenylate cyclase inhibitor SQ22536, indicating melanogenic inhibition was mediated through a cAMP-dependent signaling pathway. Immunofluorescence microscopy and glycosylation studies revealed abnormal glycosylation patterns of melanogenic proteins (tyrosinase and tyrosinase-related protein 1), and a co-localization of tyrosinase with calnexin (CNX) and lysosome-associated membrane protein 1 (LAMP-1), implicating a post-translational modification in the ER and a degradation of tyrosinase in the lysosome. Taken together, potent anti-melanogenic property and the relatively low cytotoxicity of geoditin A have demonstrated its therapeutic potential as a skin lightening agent.     

中耕苗间除草单体机构的研究与设计

中耕苗间除草单体机构是保证除草效果和控制伤苗率的关键工作部件。根据现在中耕苗间除草单体机构在实际作业中普遍存在的问题,研究设计了仿形功能好、除草效果佳、伤苗率低的中耕苗间除草单体机构。该单体机构结构简单,操作调整