Rigidin E,a New Pyrrolopyrimidine Alkaloid from a Papua New Guinea Tunicate Eudistoma Species

A new pyrrolopyrimidine alkaloid, rigidin E (1) and the known metabolites rigidin (2) and 1-methylherbipoline (3) have been isolated from a Papua New Guinea tunicate Eudistoma sp. A combination of spectroscopic data were used to determine the structures of these metabolites.     

Bactericidal activity of zinc oxide particles embedded in poly(vinyl pyrrolidone) electrospun fibers

Composites of metal oxide nanoparticles incorporated into poly(vinyl pyrrolidone) electrospun fibers can be considered potential and low cost bactericidal agents. Homogeneous distribution of nanoparticles in the core of fibers and minimal aggregation induced by strong interaction with polymeric template are factors that contribute with diffusion of metal oxide nanoparticles from bulk to the fiber surface and subsequent release of nanoparticles to bacterial culture. Hybrid electrospun fibers were successfully applied against bacteria as a result of reasonable degree of interaction between zinc oxide and fibers as detected from FTIR analysis, DSC curves and SEM images.     

Characterization of commercial iron chelates and their behavior in an alkaline and calcareous soil

Iron deficiency is a common problem for many plants grown in alkaline and calcareous soils. To correct this problem, iron is supplied to plants as chelates. Several iron chelates are sold under diverse trademarks with different characteristics. This work evaluated 18 commercial products containing the most representative chelated iron sources used in agricultural practice in Spain when the study was done, namely the ferric chelates of EDDHA, EDDHMA, EDDCHA, EDDHSA, EDTA, and DTPA. The chelates were comprehensively characterized and quantitated by several techniques, including several chromatographic methods. Iron and chelate dynamics in soil were also studied in a model alkaline and calcareous soil. Results indicate that, in this model soil, among the different iron compounds studied only FeEDDHA and analogues have the capacity to maintain soluble iron in soil solution over time. These results are in agreement with general experience under field conditions. Furthermore, among the different ortho-ortho isomers of FeEDDHA's, FeEDDHSA and FeEDDCHA showed greater capacity than FeEDDHA and FeEDDHMA to maintain the chelated iron in soil solution over time.     

东辽河流域河流系统生态需水研究

河流系统的生态需水是指维持河流正常的生态结构和功能所需要的一定水质最小水量 ,具有明显的时空变化特征。河流系统的生态用水包括河道系统 (包括排沙生态用水和水面蒸发生态用水 )和洪泛地系统两大系统的生态用水。东辽河流域河道系统生态需水量占年均径流量的 44 .43%。洪泛地生态用水量为 16 .87亿 m3,占全流域年均降水量的 2 8.0 2 %。必需采取有效措施进行河流水资源开发的有效调控。     

Factor analysis applied in genomic selection studies in the breeding of Coffea canephora

Euphytica - Head splitting is a major physiological disease in cabbage. The most effective approach for controlling head splitting is to deploy genetic resistance by breeding cabbage cultivars with...     

Assessment of the phenotypic diversity in natural populations of Annona coriacea Mart.: implications for breeding

Genetic Resources and Crop Evolution - Annona coriacea Mart. is a native tree to the savannas of Brazil that produces fruits that have economic, ecological, and dietary potential for use by local...     

Pharmaceutical,food potential,and molecular data of Hancornia speciosa Gomes: a systematic review

Genetic Resources and Crop Evolution - Hancornia speciosa Gomes is a fruit and medicinal tree species native to South America, which in Brazil is considered of potential economic value and...     

Orchid bees respond to landscape composition differently depending on the multiscale approach

Landscape Ecology - Multiscale approaches are essential for understanding ecological processes and detecting the scale of effect. However, nested multiscale approaches retain the effect of the...