Studies of O,O-dimethyl α-(2,4-dichlorophenoxyacetoxy)ethylphosphonate (HW02) as a new herbicide. 1. Synthesis and herbicidal activity of HW02 and analogues as novel inhibitors of pyruvate dehydrogenase complex     

He HW  Yuan JL  Peng H  Chen T  Shen P  Wan SQ  Li Y  Tan HL  He YH  He JB  Li Y 《Journal of agricultural and food chemistry》2011,59(9):4801-4813

On the basis of the previous work for optimization of O,O-diethyl α-(substituted phenoxyacetoxy)alkylphosphonates, further extensive synthetic modifications were made to the substituents in alkylphosphonate and phenoxy moieties of the title compounds. New O,O-dimethyl α-(substituted phenoxyacetoxy)alkylphosphonates were synthesized as potential inhibitors of pyruvate dehydorogenase complex (PDHc). Their herbicidal activity and efficacy in vitro against PDHc were examined. Some of these compounds exhibited significant herbicidal activity and were demonstrated to be effective inhibitors of PDHc from three different plants. The structure-activity relationships of these compounds including previously reported analogous compounds were studied by examining their herbicidal activities. Both inhibitory potency against PDHc and herbicidal activity of title compounds could be increased greatly by optimizing substituent groups of the title compounds. O,O-Dimethyl α-(2,4-dichlorophenoxyacetoxy)ethylphosphonate (I-5), which acted as a competitive inhibitor of PDHc with much higher inhibitory potency against PDHc from Pisum sativum and Phaseolus radiatus than from Oryza sativa , was found to be the most effective compound against broadleaf weeds and showed potential utility as herbicide.  相似文献   

Comparison of lipid content and fatty acid composition between Tuber fermentation mycelia and natural fruiting bodies     

Tang Y  Li YY  Li HM  Wan DJ  Tang YJ 《Journal of agricultural and food chemistry》2011,59(9):4736-4742

A comparison of lipid content and fatty acid (FA) composition between Tuber fermentation mycelia and natural fruiting bodies indicates that the lipid content in Tuber fermentation mycelia is higher than that in fruiting bodies. Unsaturated FAs (particularly linoleic acid and oleic acid) were the predominant constituents in total FAs in both Tuber fermentation mycelia and fruiting bodies. A total of 23 FAs, including arachidonic, eicosapentaenoic, docosahexaenoic, and γ-linolenic acids, were first identified in the Tuber species. A hierarchical clustering analysis showed that the FA profile of fermentation mycelia was quite similar, regardless of Tuber species. However, the FA profile of the fruiting bodies was significantly influenced by its species and habitat environments. Interestingly, the FA profile of the Tuber indicum and Tuber aestivum fruiting bodies was nearly identical to that of the Tuber fermentation mycelia, which partially confirms the similarity between the Tuber fermentation mycelia and the fruiting bodies.  相似文献   

基于气动PLC控制的食用菌锥形种木机   总被引：1，自引：0，他引：1  

黄小毛  万鹏  潘海兵  龙长江  李勇 《农机化研究》2011,(10)

为提高食用菌生产过程的机械化和自动化程度,提出并设计了一种食用菌锥形种木的生产机械。该机械采用可编程控制器(PLC)控制,以气缸作为执行元件,具有自动送料、削尖和下料3种功能,可与枝条生产机械、自动接种机械和装袋机等一起组成食用菌接种生产线。实验表明,该机生产锥形种木的效率为6个/min,是人工生产效率的12倍,且具有质量稳定、能够连续工作的特点。目前,该机已批量生产并将陆续投放市场。  相似文献   

带二挡变速功能电动汽车驱动系统参数设计及应用     

王燕  万媛媛 《农业装备与车辆工程》2011,(10)

主要介绍了蒂二挡变速功能电动汽车驱动系统结构和功能,以及对驱动系统中电机、变速器及超越离合器参数的选择和匹配进行了分析研究,并通过试验验证确定驱动系统参数的合理性.得出结论:带二挡变速箱可以改善电动汽车的爬坡能力,而且在高速行驶时可以将电机速度控制在额定范围内,既节能又能使各部件在较低的速度运行;超越离合器的使用,简化了汽车结构,且车辆在行驶过程中,松开加速踏板就可以换挡,减少了踩离合的麻烦;二挡变速功能的实现,降低了对蓄电池容量的要求,从而降低了汽车的质量和成本,并且也避免了由于蓄电池数量导致整车布置上的困难.  相似文献   

Protein-binding affinity of leucaena condensed tannins of differing molecular weights     

Huang XD  Liang JB  Tan HY  Yahya R  Long R  Ho YW 《Journal of agricultural and food chemistry》2011,59(19):10677-10682

Depending on their source, concentration, chemical structure, and molecular weight, condensed tannins (CTs) form insoluble complexes with protein, which could lead to ruminal bypass protein, benefiting animal production. In this study, CTs from Leuceana leucocephala hybrid were fractionated into five fractions by a size exclusion chromatography procedure. The molecular weights of the CT fractions were determined using Q-TOF LC-MS, and the protein-binding affinities of the respective CT fractions were determined using a protein precipitation assay with bovine serum albumin (BSA) as the standard protein. The calculated number-average molecular weights (M(n)) were 1348.6, 857.1, 730.1, 726.0, and 497.1, and b values (the b value represents the CT quantity that is needed to bind half of the maximum precipitable BSA) of the different molecular weight fractions were 0.381, 0.510, 0.580, 0.636, and 0.780 for fractions 1, 2, 3, 4, and 5, respectively. The results indicated that, in general, CTs of higher molecular weight fractions have stronger protein-binding affinity than those of lower molecular weights. However, the number of hydroxyl units within the structure of CT polymers also affects the protein-binding affinity.  相似文献   

Carbon exchange in a freshwater marsh in the Sanjiang Plain, northeastern China   总被引：1，自引：0，他引：1  

Changchun Song  Li Sun  Yao HuangYuesi Wang  Zhongmei Wan 《Agricultural and Forest Meteorology》2011,151(8):1131-1138

Northern wetlands are critically important to global change because of their role in modulating atmospheric concentrations of greenhouse gases, especially CO₂ and CH₄. At present, continuous observations for CO₂ and CH₄ fluxes from northern wetlands in Asia are still very limited. In this paper, two growing season measurements for CO₂ flux by eddy covariance technique and CH₄ flux by static chamber technique were conducted in 2004 and 2005, at a permanently inundated marsh in the Sanjiang Plain, northeastern China. The seasonal variations of CO₂ exchange and CH₄ flux and the environmental controls on them were investigated. During the growing seasons, large variations in net ecosystem CO₂ exchange (NEE) and gross ecosystem productivity (GEP) were observed with the range of −4.0 to 2.2 (where negative exchange is a gain of carbon from the atmosphere) and 0-7.6 g C m⁻² d⁻¹, respectively. Ecosystem respiration (RE) displayed relatively smooth seasonal pattern with the range of 0.8-4.2 g C m⁻² d⁻¹. More than 70% of the total GEP was consumed by respiration, which resulted in a net CO₂ uptake of 143 ± 9.8 and 100 ± 9.2 g C m⁻² for the marsh over the growing seasons of 2004 and 2005, respectively. A significant portion of the accumulated NEE-C was lost by CH₄ emission during the growing seasons, indicating the great potential of CH₄ emission from the inundated marsh. Air temperature and leaf area index jointly affected the seasonal variation of GEP and the seasonal dynamic of RE was mainly controlled by soil temperature and leaf area index. Soil temperature also exerted the dominant influence over variation of CH₄ flux while no significant relationship was found between CH₄ emission and water table level. The close relationships between carbon fluxes and temperature can provide insights into the response of marsh carbon exchange to a changing climate. Future long term flux measurements over the freshwater marsh ecosystems are undoubtedly necessary.  相似文献   

Genetic comparison of Brucella canis isolates by the MLVA assay in South Korea     

Kang SI  Heo EJ  Cho D  Kim JW  Kim JY  Jung SC  Her M 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2011,73(6):779-786

The multiple-locus VNTR analysis (MLVA) assay is a method frequently employed as a molecular epidemiological tool for Brucella genetic fingerprinting. The purpose of this study was to assess the genotyping of 77 B. canis isolates from 14 different dog breeding farms in Korea by the MLVA assay and to compare the epidemiological relationships between the Korean isolates and foreign ones. Simpson's diversity index for 17 loci showed a range from 0 to 0.846 in 77 B. canis isolates. B. canis isolates in Korea were observed to have high genetic diversity at the most variable loci and were divided into 30 distinct genotypes by phylogenetic analysis. Some B. canis isolates were closely related to previously typed isolates in other countries. The MLVA assay can be helpful to analyze the epidemiological correlation of B. canis isolates in domestic pet animals and to track the geographic origin by comparing the genetic patterns with foreign isolates. Therefore, the MLVA assay will be useful as a tool for control and preventive measures of canine brucellosis.  相似文献   

噬菌体对感染鸭疫里默氏菌鸭的疗效   总被引：1，自引：0，他引：1  

程龙飞  陈红梅  郑腾  施少华  傅光华  万春和  白泉阳  黄瑜 《福建畜牧兽医》2011,33(4):4-6

为观察5株鸭疫里默氏菌敏感的烈性噬菌体对传染性浆膜炎的治疗效果,将鸭疫里默氏菌RAf71人工感染樱桃谷鸭的同时皮下注射噬菌体,结果显示,不同的噬菌体能对鸭疫里默氏菌的人工感染提供不同程度的保护,噬菌体RAP44的保护率最高;噬菌体RAP44的含量越高,保护率越高。试验表明,噬菌体RAP44具备临床应用潜力,可作为生物防...  相似文献   

Enhancement of viability of a probiotic Lactobacillus strain for poultry during freeze‐drying and storage using the response surface methodology     

Anahita KHORAMNIA  Norhani ABDULLAH  Siew Ling LIEW  Chin Chin SIEO  Kalavathy RAMASAMY  Yin Wan HO 《Animal Science Journal》2011,82(1):127-135

A rotatable central composite design (CCD) was used to study the effect of cryoprotectants (skim milk, sucrose and lactose) on the survival rate of a probiotic Lactobacillus strain, L. reuteri C10, for poultry, during freeze‐drying and storage. Using response surface methodology, a quadratic polynomial equation was obtained for response value by multiple regression analyses: Y = 8.59546 ? 0.01038 X₁ ? 0.09382 X₂ ? 0.07771 X₃ ? 0.054861 X₁² ? 0.04603X₃² ? 0.10938 X₁X₂. Based on the model predicted, sucrose exerted the strongest effect on the survival rate. At various combinations of cryoprotectants, the viability loss of the cells after freeze‐drying was reduced from 1.65 log colony forming units (CFU)/mL to 0.26–0.66 log CFU/mL. The estimated optimum combination for enhancing the survival rate of L. reuteri C10 was 19.5% skim milk, 1% sucrose and 9% lactose. Verification experiments confirmed the validity of the predicted model. The storage life of freeze‐dried L. reuteri C10 was markedly improved when cryoprotectants were used. At optimum combination of the cryoprotectants, the survival rates of freeze‐dried L. reuteri C10 stored at 4°C and 30°C for 6 months were 96.4% and 73.8%, respectively. Total viability loss of cells which were not protected by cryoprotectants occurred after 12 and 8 weeks of storage at 4°C and 30°C, respectively.  相似文献   

花生的低湿密闭储藏     

万拯群 《粮食储藏》2008,37(2):13-14

为了解决花生过夏安全储藏问题,采用块状生石灰为吸湿剂,以"二合一小药袋"为缓释熏蒸剂,以五面密封为气调手段,进行了花生的低湿密闭储藏,以低湿为主导,使花生较长期处于低湿、低氧、低药的条件下,取得了安全过夏的良好效果.  相似文献