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61.
Antiviral flavonoids from the root bark of Morus alba L 总被引:7,自引:0,他引:7
A prenylated flavonoid, moralbanone, along with seven known compounds kuwanon S, mulberroside C, cyclomorusin, eudraflavone B hydroperoxide, oxydihydromorusin, leachianone G and alpha-acetyl-amyrin were isolated from the root bark of Morus alba L. Leachianone G showed potent antiviral activity (IC(50) = 1.6 microg/ml), whereas mulberroside C showed weak activity (IC(50) = 75.4 microg/ml) against herpes simplex type 1 virus (HSV-1). Their structures were elucidated by spectroscopic methods. 相似文献
62.
Biological soil crusts in ecological restoration: emerging research and perspectives 总被引:1,自引:0,他引:1
Anita Antoninka Akasha Faist Emilio Rodriguez‐Caballero Kristina E. Young V. Bala Chaudhary Lea A. Condon David A. Pyke 《Restoration Ecology》2020,28(Z2):S3-S8
Drylands encompass over 40% of terrestrial ecosystems and face significant anthropogenic degradation causing a loss of ecosystem integrity, services, and deterioration of social‐ecological systems. To combat this degradation, some dryland restoration efforts have focused on the use of biological soil crusts (biocrusts): complex communities of cyanobacteria, algae, lichens, bryophytes, and other organisms living in association with the top millimeters of soil. Biocrusts are common in many ecosystems and especially drylands. They perform a suite of ecosystem functions: stabilizing soil surfaces to prevent erosion, contributing carbon through photosynthesis, fixing nitrogen, and mediating the hydrological cycle in drylands. Biocrusts have emerged as a potential tool in restoration; developing methods to implement effective biocrust restoration has the potential to return many ecosystem functions and services. Although culture‐based approaches have allowed researchers to learn about the biology, physiology, and cultivation of biocrusts, transferring this knowledge to field implementation has been more challenging. A large amount of research has amassed to improve our understanding of biocrust restoration, leaving us at an opportune time to learn from one another and to join approaches for maximum efficacy. The articles in this special issue improve the state of our current knowledge in biocrust restoration, highlighting efforts to effectively restore biocrusts through a variety of different ecosystems, across scales and utilizing a variety of lab and field methods. This collective work provides a useful resource for the scientific community as well as land managers. 相似文献
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StructureSelector: A web‐based software to select and visualize the optimal number of clusters using multiple methods 下载免费PDF全文
Inferences of population genetic structure are of great importance to the fields of ecology and evolutionary biology. The program structure has been widely used to infer population genetic structure. However, previous studies demonstrated that uneven sampling often leads to wrong inferences on hierarchical structure. The most widely used ΔK method tends to identify the uppermost hierarchy of population structure. Recently, four alternative statistics (medmedk , medmeak , maxmedk and maxmeak ) were proposed, which appear to be more accurate than the previously used methods for both even and uneven sampling data. However, the lack of easy‐to‐use software limits the use of these appealing new estimators. Here, we developed a web‐based user‐friendly software structureselector to calculate the four appealing alternative statistics together with the commonly used Ln Pr(X|K) and ΔK statistics. structureselector accepts the result files of structure , admixture or faststructure as input files. It reports the “best” K for each estimator, and the results are available as HTML or tab separated tables. The program can also generate graphical representations for specific K, which can be easily downloaded from the server. The software is freely available at http://lmme.qdio.ac.cn/StructureSelector/ . 相似文献
65.
Lipidomic changes during different growth stages of Nitzschia closterium f. minutissima 总被引:3,自引:0,他引:3
Xiaoling Su Jilin Xu Xiaojun Yan Peng Zhao Juanjuan Chen Chengxu Zhou Fang Zhao Shuang Li 《Metabolomics : Official journal of the Metabolomic Society》2013,9(2):300-310
Ultra Performance Liquid Chromatography-Electrospray ionization-Quadrupole-Time of Flight Mass Spectrometry (UPLC-ESI-Q-TOF–MS) is a powerful lipidomic tool. In this study, we developed a UPLC/Q-TOF–MS based method to investigate the lipid metabolomic changes in different growth phases of Nitzschia closterium f. minutissima. The data classification and biomarker selection were carried out by using multivariate statistical analysis, including principal components analysis (PCA), projection to latent structures with discriminant analysis (PLS-DA), and orthogonal projection to latent structures with discriminant analysis (OPLS-DA). We discovered that the intercellular lipid metabolites were significantly different among exponential, early stationary and late stationary phases. Thirty-one lipid molecules were selected and identified as putative biomarkers, including free fatty acid, Harderoporphyrin, phosphatidylglycerol, 1,2-diacyglycerl-3-O-4′-(N,N-trimethy)-homoserine, triacylglycerol, cholesterol, sulfoquinovosyldiacylglycerol, lyso-sulfoquinovosyldiacylglycerol, monogalactosyldiacylglycerol, digalactosyldiacylglycerol and lyso-digalactosyldiacylglycerol. These lipids have been shown previously to function in energy storage, membrane stability and photosynthesis efficiency during the growth of diatoms. Further analysis on the putative biomarkers demonstrated that nitrate starvation played critical role in the transition from exponential phase to stationary phase in N. closterium. This study is the first one to explore the lipidomic changes of microalgae in different growth phases, which promotes better understanding of their physiology and ecology. 相似文献
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Shibin Gao Carlos Martinez Debra J. Skinner Alan F. Krivanek Jonathan H. Crouch Yunbi Xu 《Molecular breeding : new strategies in plant improvement》2008,22(3):477-494
Leaf collection from the field, labeling and tracking back to the source plants after genotyping are rate limiting steps in
leaf DNA-based genotyping. In this study, an optimized genotyping method using endosperm DNA sampled from single maize seeds
was developed, which can be used to replace leaf DNA-based genotyping for both genetic studies and breeding applications.
A similar approach is likely to be suitable for all plants with relatively large seeds. Part of the endosperm was excised
from imbibed maize seeds and DNA extracted in 96-tube plates using individuals from eight F2 populations and seven inbreds. The quality of the resultant DNA was functionally comparable to DNA extracted from leaf tissue.
Extraction from 30 mg of endosperm yields 3–10 μg DNA, which is sufficient for analysis of 200–400 agarose-gel PCR-based markers,
with the potential for several million chip-based SNP marker analyses. By comparing endosperm DNA and leaf DNA for individuals
from an F2 population, genotyping errors caused by pericarp contamination and hetero-fertilization were found to average 3.8 and 0.6%,
respectively. Endosperm sampling did not affect germination rates under controlled conditions, although under normal field
conditions the germination rate, seedling establishment, and growth vigor were significantly lower than that of non-sampled
controls for some genotypes. However, careful field management can compensate for these effects. Seed DNA-based genotyping
lowered costs by 24.6% compared to leaf DNA-based genotyping due to reduced field plantings and labor costs. A substantial
advantage of this approach is that it can be used to select desirable genotypes before planting. As such it provides an opportunity
for dramatic improvements in the efficiency and selective gain of breeding systems based on optimum combinations of marker-assisted
selection and phenotypic selection within and between generations. 相似文献