970 research outputs found
3,3′-(2,2′-Bi-1H-imidazole-1,1′-diÂyl)dipropanamide. Corrigendum
Corrigendum to Acta Cryst. (2009), E65, o2008
Detecting unambiguously non-Abelian geometric phases with trapped ions
We propose for the first time an experimentally feasible scheme to disclose
the noncommutative effects induced by a light-induced non-Abelian gauge
structure with trapped ions. Under an appropriate configuration, a true
non-Abelian gauge potential naturally arises in connection with the geometric
phase associated with two degenerated dark states in a four-state atomic system
interacting with three pulsed laser fields. We show that the population in
atomic state at the end of a composed path formed by two closed loops and
in the parameter space can be significantly different from the composed
counter-ordered path. This population difference is directly induced by the
noncommutative feature of non-Abelian geometric phases and can be detected
unambiguously with current technology.Comment: 6 page
Cytotoxicity of Essential Oil of Chenopodium ambrosioides L against Human Breast Cancer MCF-7 Cells
Purpose: To investigate the cytotoxic activity of the essential oil of Chenopodium ambrosioides L. against human breast cancer MCF-7 cells.Methods: Cytotoxicity was characterized by 50 % inhibition (IC50) of human breast cancer cell lines (MCF-7) using 3-(4,5-dimethylthaizol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Apoptosis was analysed by Hoechst33258 staining and DNA ladder. MCF-7 cellular superoxide dismutase (SOD), catalase (CAT) vitality and malondialdehyde (MDA) content were evaluated.Results: The essential oil was cytotoxic to MCF-7 cell line. A dose- and time-dependent inhibition was observed with IC50 values of 18.75, 9.45 and 10.50 μg/ml at 6, 24 and 48 h, respectively. Analyses by Hoechst33258 staining and DNA ladder indicate that the essential oil induced apoptosis. SOD vitality significantly decreased (p< 0.05) by 51 % when the concentration of the essential oil increased from 1.25 to 12.5 μg/ml while CAT vitality significantly increased (p < 0.05) by 71 % when essential oil concentration was similarly increased. The MDA content of each treatment group, when compare to control, did not show any significant difference (p < 0.05).Conclusion: The essential oil of C. ambrosioides was cytotoxic to MCF-7 cell line and induced apoptosis.Keywords: Chenopodium ambrosioides L., Essential oil, Cytotoxicity, Apoptosis, Breast cancer, MCF-7 cells
Strong quantum fluctuation of vortices in the new superconductor
By using transport and magnetic measurement, the upper critical field
and the irreversibility line has been determined. A
big separation between and has been found showing the
existence of a quantum vortex liquid state induced by quantum fluctuation of
vortices in the new superconductor . Further investigation on the
magnetic relaxation shows that both the quantum tunneling and the thermally
activated flux creep weakly depends on temperature. But when the melting field
is approached, a drastic rising of the relaxation rate is observed.
This may imply that the melting of the vortex matter at a finite temperature is
also induced by the quantum fluctuation of vortices.Comment: 4 pages, 4 figure
DIGITAL SOIL MAPPING FOR SMART AGRICULTURE: THE SOLIM METHOD AND SOFTWARE PLATFORMS
The key challenges faced by many of the existing digital soil mapping (DSM) techniques are the rigid requirements on the size of soil samples to extract the relationships needed and on the stationarity of the extracted relationships. These requirements limit the application of these DSM techniques. This paper provides an overview of the SoLIM approach and an introduction to the operation of SoLIM through the software platforms available. SoLIM is based on the Third Law of Geography, which calls for the comparison of similarity in geographic (environmental) configuration of a prototype and an unsampled location and then use this similarity to predict the value of a soil property at a given location. DSM under SoLIM approach removes requirements on the sample size and the stationarity assumption. In addition, the uncertainty computed based on the similarities can be used to improve the efficiency of error reduction efforts. The SoLIM approach has been implemented in two platforms: SoLIM Solutions and CyberSoLIM. The theoretical foundation and the availability of software platforms under SoLIM make DSM possible and convenient over large and complex geographic regions
Parallel momentum distribution of the Si fragments from P
Distribution of the parallel momentum of Si fragments from the breakup
of 30.7 MeV/nucleon P has been measured on C targets. The distribution
has the FWHM with the value of 110.5 23.5 MeV/c which is consistent
quantitatively with Galuber model calculation assuming by a valence proton in
P. The density distribution is also predicted by Skyrme-Hartree-Fock
calculation. Results show that there might exist the proton-skin structure in
P.Comment: 4 pages, 4 figure
AgBioData consortium recommendations for sustainable genomics and genetics databases for agriculture
The future of agricultural research depends on data. The sheer volume of agricultural biological data being produced today makes excellent data management essential. Governmental agencies, publishers and science funders require data management plans for publicly funded research. Furthermore, the value of data increases exponentially when they are properly stored, described, integrated and shared, so that they can be easily utilized in future analyses. AgBioData (https://www.agbiodata.org) is a consortium of people working at agricultural biological databases, data archives and knowledgbases who strive to identify common issues in database development, curation and management, with the goal of creating database products that are more Findable, Accessible, Interoperable and Reusable. We strive to promote authentic, detailed, accurate and explicit communication between all parties involved in scientific data. As a step toward this goal, we present the current state of biocuration, ontologies, metadata and persistence, database platforms, programmatic (machine) access to data, communication and sustainability with regard to data curation. Each section describes challenges and opportunities for these topics, along with recommendations and best practices
Ab initio simulations of the kinetic properties of the hydrogen monomer on graphene
The understanding of the kinetic properties of hydrogen (isotopes) adatoms on
graphene is important in many fields. The kinetic properties of
hydrogen-isotope (H, D and T) monomers were simulated using a composite method
consisting of density functional theory, density functional perturbation theory
and harmonic transition state theory. The kinetic changes of the magnetic
property and the aromatic bond of the hydrogenated graphene during the
desorption and diffusion of the hydrogen monomer was discussed. The vibrational
zero-point energy corrections in the activation energies were found to be
significant, ranging from 0.072 to 0.205 eV. The results obtained from
quantum-mechanically modified harmonic transition state theory were compared
with the ones obtained from classical-limit harmonic transition state theory
over a wide temperature range. The phonon spectra of hydrogenated graphene were
used to closely explain the (reversed) isotope effects in the prefactor,
activation energy and jump frequency of the hydrogen monomer. The kinetic
properties of the hydrogen-isotope monomers were simulated under conditions of
annealing for 10 minutes and of heating at a constant rate (1.0 K/s). The
isotope effect was observed; that is, a hydrogen monomer of lower mass is
desorbed and diffuses more easily (with lower activation energies). The results
presented herein are very similar to other reported experimental observations.
This study of the kinetic properties of the hydrogen monomer and many other
involved implicit mechanisms provides a better understanding of the interaction
between hydrogen and graphene.Comment: Accepted by J. Phys. Chem.
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