4,557 research outputs found
Isolation and characterization of antimicrobial, anti-inflammatory and chemopreventive flavones from premna odorata blanco
Premna odorata Blanco (Verbenaceae) is a native tree of the Philippines where its leaves are used traditionally for vaginal irrigation and tuberculosis. It is one of the seven components of a commercialized Philippine herbal preparation called "Pito-Pito". Its medicinal uses, however, have not been scientifically validated. This tree is not commonly cultivated and thrive in the less accessible limestone forests of the Philippines. Solvent partitioning and fractionation of the ethanolic crude extract of the leaves isolated two yellow amorphous powders. The identities of these compounds were determined by LC/MS/MS and NMR spectroscopic analyses, and their spectra were compared with literature data. The isolates were flavone aglycones which were the widespread acacetin and the nonwidespread diosmetin. These flavones were isolated from the P. odorata for the first time ever. They had been reported by earlier studies to exhibit medicinal properties as antimicrobial, anti-inflammatory and chemopreventive. Thus, the current study has provided a scientific evidence of the medicinal properties of the leaves of P. odorata that could become the popular basis for the plant's sustainable use, conservation and cultivation. © 2011 Academic Journals.published_or_final_versio
In Arabidopsis hybrids and Hybrid Mimics, up-regulation of cell wall biogenesis is associated with the increased plant size
© 2019 The Authors. Plant Direct published by American Society of Plant Biologists, Society for Experimental Biology and John Wiley & Sons Ltd. Hybrid breeding is of economic importance in agriculture for increasing yield, yet the basis of heterosis is not well understood. In Arabidopsis, crosses between different accessions produce hybrids with different levels of heterosis relative to parental phenotypes in biomass. In all hybrids, the advantage of the F1 hybrid in both phenotypic uniformity and yield gain is lost in the heterogeneous F2. F5/F6 Hybrid Mimics generated from a cross between C24 and Landsberg erecta (Ler) ecotypes demonstrated that the large plant phenotype of the F1 hybrids can be stabilized. Hybrid Mimic selection was applied to Wassilewskija (Ws)/Ler and Col/Ler hybrids. The two hybrids show different levels of heterosis. The Col/Ler hybrid generated F7 Hybrid Mimics with rosette diameter and fresh weight equivalent to the F1 hybrid at 30 DAS; F7 Ws/Ler Hybrid Mimics outperformed the F1 hybrid in both the rosette size and biomass. Transcriptome analysis revealed up-regulation of cell wall biosynthesis, and cell wall expansion genes could be a common pathway in increased size in the Arabidopsis hybrids and Hybrid Mimics. Intercross of two independent Hybrid Mimic lines can further increase the biomass gain. Our results encourage the use of Hybrid Mimics for breeding and for investigating the molecular basis of heterosis
Very strong intrinsic supercurrent carrying ability and vortex avalanches in (Ba,K)Fe2As2 superconducting single crystals
We report that single crystals of (Ba,K)Fe2As2 with Tc = 32 K have a pinning
potential, U0, as high as 10^4 K, with U0 showing very little field
depend-ence. In addition, the (Ba,K)Fe2As2 single crystals become isotropic at
low temperatures and high magnetic fields, resulting in a very rigid vortex
lattice, even in fields very close to Hc2. The rigid vortices in the two
dimensional (Ba,K)Fe2As2 distinguish this compound from 2D high Tc cuprate
superconductors with 2D vortices, and make it being capable of cearrying very
high critical current.Flux jumping due to high Jc was also observed in large
samples at low temperatures.Comment: 4 pages, 7 figures. submitte
Imaging the Phase Transformation in Single Particles of the Lithium Titanate Anode for Lithium-Ion Batteries
Lithium uptake and release in lithium titanate (LTO) anode materials during a discharge and charge cycle is one of the fundamental processes of a lithium-ion battery (LIB), still not fully understood at the microscopic level. During the discharge cycle, LTO undergoes a phase transformation between Li4Ti5O12 and Li7Ti5O12 states within a cubic crystal lattice. To reveal the details of the microscopic mechanism, it is necessary to track the sequence of phase transformations at different discharge/charge states under operating conditions. Here, we use in situ Bragg coherent diffraction imaging (BCDI) and in situ X-ray diffraction (XRD) experiments to examine the lithium insertion-induced materials phase transformation within a single LTO particle and a bulk battery analogue, respectively. BCDI analysis from (111) Bragg peak shows the two-phase transformation manifesting as a distinct image phase modulation within a single LTO nanoparticle occurring in the middle of the discharge region then subsiding toward the end of the discharge cycle. We observe the biggest phase variation at the two-phase stage, indicating the formation of phase domains of 200 nm in size during the discharge process. We also observe a lattice contraction of >0.2% in a single LTO nanoparticle at the (400) Bragg peak measurement, larger than that in the corresponding bulk material. Our observation of this phase transformation at a single-particle level has implications for the understanding of the microscopic/mesoscale picture of the phase transformation in anode and cathode LIBs materials
Magnetic separation-based blood purification: a promising new approach for the removal of disease-causing compounds?
Real Space Imaging of Spin Stripe Domain Fluctuations in a Complex Oxide
Understanding the formation and dynamics of charge and spin-ordered states in low-dimensional transition metal oxide materials is crucial to understanding unconventional high-temperature superconductivity. La2−xSrxNiO4þδ (LSNO) has attracted much attention due to its interesting spin dynamics. Recent x-ray photon correlation spectroscopy studies have revealed slow dynamics of the spin order (SO) stripes in LSNO. Here, we applied resonant soft x-ray ptychography to map the spatial distribution of the SO stripe domain inhomogeneity in real space. The reconstructed images show the SO domains are spatially anisotropic, in agreement with previous diffraction studies. For the SO stripe domains, it is found that the correlation lengths along different directions are strongly coupled in space. Surprisingly, fluctuations were observed in the real space amplitude signal, rather than the phase or position. We attribute the observed slow dynamics of the stripe domains in LSNO to thermal fluctuations of the SO domain boundaries
Unconventional superconductivity of NdFeAsO0.82F0.18 indicated by the low temperature dependence of the lower critical field Hc1
We measured the initial M-H curves for a sample of the newly discovered
superconductor NdFeAsO0.82Fe0.18, which had a critical temperature, Tc, of 51
K, and was fabricated at the high pressure of 6 GPa. The lower critical field,
Hc1, was extracted from the deviation point of the Meissner linearity in the
M-H curves, which show linear temperature dependence in the low temperature
region down to 5 K. The Hc1(T) indicates no s-wave superconductivity, but
rather an unconventional superconductivity with a nodal gap structure.
Furthermore, the linearity of Hc1 at low temperature does not hold at high
temperature, but shows other characteristics, indicating that this
superconductor might have multi-gap features. Based on the low temperature
nodal gap structure, we estimate that the maximum gap magnitude delta 0 =
(1.6+- 0.2) kBTc.Comment: 8 pages, 3 figure
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