1,524 research outputs found
Degradation of adhesion molecules of G361 melanoma cells by a non-thermal atmospheric pressure microplasma
Increased expression of integrins and focal adhesion kinase (FAK)
is important for the survival, growth and metastasis of melanoma cells. Based on
this well-established observation in oncology, we propose to use degradation of
integrin and FAK proteins as a potential strategy for melanoma cancer therapy. A
low-temperature radio-frequency atmospheric microplasma jet is used to study
their effects on the adhesion molecules of G361 melanoma cells. Microplasma
treatment is shown to (1) cause significant cell detachment from the bottom of
microtiter plates coated with collagen, (2) induce the death of human melanoma
cells, (3) inhibit the expression of integrin 2, integrin 4 and FAK on the cell
surface and finally (4) change well-stretched actin filaments to a diffuse pattern.
These results suggest that cold atmospheric pressure plasmas can strongly inhibit
the adhesion of melanoma cells by reducing the activities of adhesion proteins
such as integrins and FAK, key biomolecules that are known to be important in
malignant transformation and acquisition of metastatic phenotypes
Stochastic String Motion Above and Below the World Sheet Horizon
We study the stochastic motion of a relativistic trailing string in black
hole AdS_5. The classical string solution develops a world-sheet horizon and we
determine the associated Hawking radiation spectrum. The emitted radiation
causes fluctuations on the string both above and below the world-sheet horizon.
In contrast to standard black hole physics, the fluctuations below the horizon
are causally connected with the boundary of AdS. We derive a bulk stochastic
equation of motion for the dual string and use the AdS/CFT correspondence to
determine the evolution a fast heavy quark in the strongly coupled
plasma. We find that the kinetic mass of the quark decreases by while the correlation time of world sheet
fluctuations increases by .Comment: 27 pages, 5 figures; v2 final version, small changes, references
adde
Spontaneous CP Violating Phase as The CKM Matrix Phase
We propose that the CP violating phase in the CKM mixing matrix is identical
to the CP phases responsible for the spontaneous CP violation in the Higgs
potential. A specific multi-Higgs model with Peccei-Quinn (PQ) symmetry is
constructed to realize this idea. The CP violating phase does not vanish when
all Higgs masses become large. There are flavor changing neutral current (FCNC)
interactions mediated by neutral Higgs bosons at the tree level. However,
unlike general multi-Higgs models, the FCNC Yukawa couplings are fixed in terms
of the quark masses and CKM mixing angles. Implications for meson-anti-meson
mixing, including recent data on mixing, and neutron electric dipole
moment (EDM) are studied. We find that the neutral Higgs boson masses can be at
the order of one hundred GeV. The neutron EDM can be close to the present
experimental upper bound.Comment: 16 pages, RevTex. Several typos corrected, and one reference adde
Bundle and annulus CHF correlations applicable for near critical pressure region
Paper presented at the 8th International Conference on Heat Transfer, Fluid Mechanics and Thermodynamics, Mauritius, 11-13 July, 2011.Bundle and annulus CHF correlations are developed by
using CHF experimental data from the Freon R-134a Thermal
Hydraulic Experimental Loop developed at KAERI. The CHF
data are in the range of the pressure of 3200 ~ 4030 kPa
(Critical pressure of R-134a = 4059 kPa), the mass flux
150∼1500 kg/m2s, and the inlet subcooling 40 ~ 70 kJ/kg. We
obtained local T/H values using a subchannel analysis code and
produced CHF correlations for the matrix subchannel, coldwall
subchannel and annulus channel, respectively. A
subchannel code, The MATRA-α IBM PC version, is used to
obtain the local conditions in a hot subchannel (CHF observed
channel) in the 5x5 bundle geometry. All the CHF experimental
data are successfully calculated by the present correlations with
good prediction performance. The prediction accuracy of the
correlations is not distorted by much in any of the ranges of the
independent parameters. The bundle CHF correlations could
help one to conceptually design a SCWR, by adopting a fluidto-
fluid modeling technique for a CHF near a critical pressure.mp201
Spontaneous CP Violation in a SUSY Model with a complex CKM
It is pointed out that the recent measurement of the angle of the
unitarity triangle, providing irrefutable evidence for a complex
Cabibbo-Kobayashi-Maskawa (CKM) matrix, presents a great challenge for
supersymmetric models with spontaneous CP violation. We construct a new minimal
extension of the minimal supersymmetric standard model (MSSM), with spontaneous
CP breaking, which leads to a complex CKM matrix, thus conforming to present
experimental data. This is achieved through the introduction of two singlet
chiral superfields and a vector-like quark chiral superfield which mixes with
the standard quarks. A symmetry is introduced in order to have a
potential solution to the strong CP problem.Comment: 12 pages. Uses the elsart.cls LaTeX class. Minor corrections and
references adde
COSMOGRAIL: XVII. Time delays for the quadruply imaged quasar PG 1115+080
Indexación: Scopus.Acknowledgements. The authors would like to thank R. Gredel for his help in setting up the program at the ESO MPIA 2.2 m telescope, and the anonymous referee for his or her comments on this work. This work is supported by the Swiss National Fundation. This research made use of Astropy, a community-developed core Python package for Astronomy (Astropy Collaboration et al. 2013, 2018) and the 2D graphics environment Matplotlib (Hunter 2007). K.R. acknowledge support from PhD fellowship FIB-UV 2015/2016 and Becas de Doctorado Nacional CONICYT 2017 and thanks the LSSTC Data Science Fellowship Program, her time as a Fellow has benefited this work. M.T. acknowledges support by the DFG grant Hi 1495/2-1. G. C.-F. C. acknowledges support from the Ministry of Education in Taiwan via Government Scholarship to Study Abroad (GSSA). D. C.-Y. Chao and S. H. Suyu gratefully acknowledge the support from the Max Planck Society through the Max Planck Research Group for S. H. Suyu. T. A. acknowledges support by the Ministry for the Economy, Development, and Tourism’s Programa Inicativa CientÃfica Milenio through grant IC 12009, awarded to The Millennium Institute of Astrophysics (MAS).We present time-delay estimates for the quadruply imaged quasar PG 1115+080. Our results are based on almost daily observations for seven months at the ESO MPIA 2.2 m telescope at La Silla Observatory, reaching a signal-to-noise ratio of about 1000 per quasar image. In addition, we re-analyze existing light curves from the literature that we complete with an additional three seasons of monitoring with the Mercator telescope at La Palma Observatory. When exploring the possible source of bias we considered the so-called microlensing time delay, a potential source of systematic error so far never directly accounted for in previous time-delay publications. In 15 yr of data on PG 1115+080, we find no strong evidence of microlensing time delay. Therefore not accounting for this effect, our time-delay estimates on the individual data sets are in good agreement with each other and with the literature. Combining the data sets, we obtain the most precise time-delay estimates to date on PG 1115+080, with Δt(AB) = 8.3+1.5 -1.6 days (18.7% precision), Δt(AC) = 9.9+1.1 -1.1 days (11.1%) and Δt(BC) = 18.8+1.6 -1.6 days (8.5%). Turning these time delays into cosmological constraints is done in a companion paper that makes use of ground-based Adaptive Optics (AO) with the Keck telescope. © ESO 2018.https://www.aanda.org/articles/aa/abs/2018/08/aa33287-18/aa33287-18.htm
Heavy quark in an expanding plasma in AdS/CFT
Using the Janik-Peschanski dual to a Bjorken flow, a Langevin equation is
derived for a heavy quark in an expanding N = 4 supersymmetric Yang-Mills
plasma. Such a plasma is characterized by a proper-time dependence of the
temperature and corresponds to a system out of equilibrium. The analysis first
focuses on a quark at rest in the plasma comoving frame. The case of a quark
moving across a longitudinally expanding plasma is then considered. The
two-point functions for the random noise acting on such heavy quark probes are
computed.Comment: 17 pages. v2: references added; improved comments on the
Schwinger-Keldysh formalis
Electroactive biofilms: new means for electrochemistry
This work demonstrates that electrochemical reactions can be catalysed by the natural biofilms that form on
electrode surfaces dipping into drinking water or compost. In drinking water, oxygen reduction was monitored with
stainless steel ultra-microelectrodes under constant potential electrolysis at )0.30 V/SCE for 13 days. 16 independent experiments were conducted in drinking water, either pure or with the addition of acetate or dextrose. In
most cases, the current increased and reached 1.5–9.5 times the initial current. The current increase was attributed to
biofilm forming on the electrode in a similar way to that has been observed in seawater. Epifluorescence microscopy
showed that the bacteria size and the biofilm morphology depended on the nutrients added, but no quantitative
correlation between biofilm morphology and current was established. In compost, the oxidation process was
investigated using a titanium based electrode under constant polarisation in the range 0.10–0.70 V/SCE. It was
demonstrated that the indigenous micro-organisms were responsible for the current increase observed after a few
days, up to 60 mA m)2. Adding 10 mM acetate to the compost amplified the current density to 145 mA m)2 at 0.50 V/SCE. The study suggests that many natural environments, other than marine sediments, waste waters and
seawaters that have been predominantly investigated until now, may be able to produce electrochemically active
biofilm
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