249 research outputs found
AtKinesin-13A is located on Golgi-associated vesicle and involved in vesicle formation/budding in Arabidopsis root-cap peripheral cells
<p>Abstract</p> <p>Background</p> <p>AtKinesin-13A is an internal-motor kinesin from Arabidopsis (<it>Arabidopsis thaliana</it>). Previous immunofluorescent results showed that AtKinesin-13A localized to Golgi stacks in plant cells. However, its precise localization and biological function in Golgi apparatus is unclear.</p> <p>Results</p> <p>In this paper, immunofluorescent labeling and confocal microscopic observation revealed that AtKinesin-13A was co-localized with Golgi stacks in Arabidopsis root tip cells. Immuno-electron microscopic observations indicated that AtKinesin-13A is primarily localized on Golgi-associated vesicles in Arabidopsis root-cap cells. By T-DNA insertion, the inactivation of the <it>AtKinesin-13A </it>gene (NM-112536) resulted in a sharp decrease of size and number of Golgi vesicles in root-cap peripheral cells. At the same time, these cells were vacuolated in comparison to the corresponding cells of the wild type.</p> <p>Conclusion</p> <p>These results suggest that AtKinesin-13A decorates Golgi-associated vesicles and may be involved in regulating the formation of Golgi vesicles in the root-cap peripheral cells in Arabidopsis.</p
Preparation, evaluation, and pharmacokinetics in beagle dogs of a taste-masked flunixin meglumine orally disintegrating tablet prepared using hot-melt extrusion technology and D-optimal mixture design
Flunixin meglumine (FM) is a nonsteroidal anti-inflammatory drug limited by irritation of the respiratory tract and mucosa in veterinary tissue. This study aimed to develop a taste-masked FM solid dispersion (SD) by hot-melt extrusion (HME) and formulate an orally disintegrating tablet (ODT) with selected excipients by direct compression. Eudragit® E PO was chosen as the matrix, and HME parameters were optimized: extrusion temperature, 135℃; screw speed, 100 rpm; and drug loading, 20%. Characterization techniques proved that FM was rendered amorphous in the HME extrudate. In vitro dissolution studies showed that FM SD released significantly slower than the corresponding physical mixture in artificial saliva. Excipients were selected based on compression formability, disintegration, and solubility. A D-optimal mixture design was used to optimize the composition: 25% FM SD, 18.75% microcrystalline cellulose, 52.5% mannitol, 3.75% low-substituted hydroxypropyl cellulose, and 1% magnesium stearate. Taste-masked FM ODT had a tensile strength of 0.7 ± 0.01 MPa and a disintegration time of 17.6 ± 0.1 s. E-tongue and E-nose analysis showed that FM ODT had a better taste-masked effect than commercial granules. Finally, a pharmacokinetic study proved that the main pharmacokinetic parameters of FM ODT were not significantly different from those of commercial granules, which indicated that these formulations had similar pharmacokinetic behaviours in beagles
Growth of Thin Oxidation-Resistive Crystalline Si Nanostructures on Graphene
We report the growth of Si nanostructures, either as thin films or
nanoparticles, on graphene substrates. The Si nanostructures are shown to be
single crystalline, air stable and oxidation resistive, as indicated by the
observation of a single crystalline Si Raman mode at around 520 cm-1, a STM
image of an ordered surface structure under ambient condition, and a Schottky
junction with graphite. Ultra-thin silicon regions exhibit silicene-like
behavior, including a Raman mode at around 550 cm-1, a triangular lattice
structure in STM that has distinctly different lattice spacing from that of
either graphene or thicker Si, and metallic conductivity of up to 500 times
higher than that of graphite. This work suggests a bottom-up approach to
forming a Si nanostructure array on a large scale patterned graphene substrate
for fabricating nanoscale Si electronic devices
Observation of the Josephson effect in Pb/(Ba,K)Fe2As2 single crystal junctions
We have fabricated c-axis Josephson junctions on single crystals of
(Ba,K)Fe2As2 by using Pb as the counter electrode in two geometries, planar and
point contact. Junctions in both geometries show resistively shunted junction
I-V curves below the Tc of the counter electrode. Microwave induced steps were
observed in the I-V curves, and the critical currents are suppressed with an
in-plane magnetic field in a manner consistent with the small junction limit.
ICRN products of up to 0.3 mV have been observed in these junctions at 4.2 K.
The observation of Josephson coupling along the c-axis between (Ba,K)Fe2As2 and
a conventional superconductor suggests the existence of a s-wave
superconducting order parameter in this class of iron pnictide superconductors.Comment: 16 pages and 3 figure
Finite element method for one-dimensional rill erosion simulation on a curved slope
AbstractRill erosion models are important to hillslope soil erosion prediction and to land use planning. The development of rill erosion models and their use has become increasingly of great concern. The purpose of this research was to develop mathematic models with computer simulation procedures to simulate and predict rill erosion. The finite element method is known as an efficient tool in many other applications than in rill soil erosion. In this study, the hydrodynamic and sediment continuity model equations for a rill erosion system were solved by the Galerkin finite element method and Visual C++ procedures. The simulated results are compared with the data for spatially and temporally measured processes for rill erosion under different conditions. The results indicate that the one-dimensional linear finite element method produced excellent predictions of rill erosion processes. Therefore, this study supplies a tool for further development of a dynamic soil erosion prediction model
Mitochondrial COI sequences revealed shallow but significant divergences among Amphioctopus aegina (Octopoda, Octopodidae) populations in coastal waters of China
Amphioctopus aegina is an important fishery resource in the coastal waters of China. In the present study, the genetic diversity and population genetic structure among four populations of A. aegina throughout its distributional range in China were assessed using the mitochondrial cytochrome oxidase 1 (COI) sequences. The results revealed a generally low genetic diversity (Hd: 0.2842–0.6670; Pi: 0.0007–0.0015) in A. aegina populations. The neighbor-joining (NJ) phylogenetic tree and the haplotype networks, as well as the results of the molecular variance (AMOVA) analyses, indicated a shallow phylogeographic structure among the four populations. However, pairwise ΦST statistics and genetic distance analyses revealed significant (p<0.01) genetic differentiation among Qinzhou and the rest three populations of Zhanjiang, Huizhou, and Dongshan. The demographic history analyses indicated a population expansion in A. aegina, and the role of Leizhou peninsula isolation in shaping the population differentiation. These results would largely enhance our understanding of the genetic structure and hence promote the scientific management of A. aegina fishery resources in coastal waters of China
Evidence of a universal and isotropic 2\Delta/kBTC ratio in 122-type iron pnictide superconductors over a wide doping range
We have systematically investigated the doping and the directional dependence
of the gap structure in the 122-type iron pnictide superconductors by point
contact Andreev reflection spectroscopy. The studies were performed on single
crystals of Ba1-xKxFe2As2 (x = 0.29, 0.49, and 0.77) and SrFe1.74Co0.26As2 with
a sharp tip of Pb or Au pressed along the c-axis or the ab-plane direction. The
conductance spectra obtained on highly transparent contacts clearly show
evidence of a robust superconducting gap. The normalized curves can be well
described by the Blonder-Tinkham-Klapwijk model with a lifetime broadening. The
determined gap value scales very well with the transition temperature, giving
the 2{\Delta}/kBTC value of ~ 3.1. The results suggest the presence of a
universal coupling behavior in this class of iron pnictides over a broad doping
range and independent of the sign of the doping. Moreover, conductance spectra
obtained on c-axis junctions and ab-plane junctions indicate that the observed
gap is isotropic in these superconductors
Cybernetic basis and system practice of remote sensing and spatial information science
Cybernetics provides a new set of ideas and methods for the study of modern science, and it has been fully applied in many areas. However, few people have introduced cybernetics into the field of remote sensing. The paper is based on the imaging process of remote sensing system, introducing cybernetics into the field of remote sensing, establishing a space-time closed-loop control theory for the actual operation of remote sensing. The paper made the process of spatial information coherently, and improved the comprehensive efficiency of the space information from acquisition, procession, transformation to application. We not only describes the application of cybernetics in remote sensing platform control, sensor control, data processing control, but also in whole system of remote sensing imaging process control. We achieve the information of output back to the input to control the efficient operation of the entire system. This breakthrough combination of cybernetics science and remote sensing science will improve remote sensing science to a higher level
Flatband Line States in Photonic Super-Honeycomb Lattices
We establish experimentally a photonic super-honeycomb lattice (sHCL) by use
of a cw-laser writing technique, and thereby demonstrate two distinct flatband
line states that manifest as noncontractible-loop-states in an infinite
flatband lattice. These localized states (straight and zigzag lines) observed
in the sHCL with tailored boundaries cannot be obtained by superposition of
conventional compact localized states because they represent a new topological
entity in flatband systems. In fact, the zigzag-line states, unique to the
sHCL, are in contradistinction with those previously observed in the Kagome and
Lieb lattices. Their momentum-space spectrum emerges in the high-order
Brillouin zone where the flat band touches the dispersive bands, revealing the
characteristic of topologically protected bandcrossing. Our experimental
results are corroborated by numerical simulations based on the coupled mode
theory. This work may provide insight to Dirac like 2D materials beyond
graphene
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