32 research outputs found
Holographic Superconductors in a Cohesive Phase
We consider a four-dimensional N=2 gauged supergravity coupled to matter
fields. The model is obtained by a U(1) gauging of a charged hypermultiplet and
therefore it is suitable for the study of holographic superconductivity. The
potential has a topologically flat direction and the parameter running on this
"moduli space" labels the new superconducting black holes. Zero temperature
solutions are constructed and the phase diagram of the theory is studied. The
model has rich dynamics. The retrograde condensate is just a special case in
the new class of black holes. The calculation of the entanglement entropy makes
manifest the properties of a generic solution and the superconductor at zero
temperature is in a confined cohesive phase. The parameter running on the
topologically flat direction is a marginal coupling in the dual field theory.
We prove this statement by considering the way double trace deformations are
treated in the AdS/CFT correspondence. Finally, we comment on a possible
connection, in the context of gauge/gravity dualities, between the geometry of
the scalar manifold in N=2 supergravity models and the space of marginal
deformations of the dual field theory.Comment: 32 pages, 11 figures. Introduction rewritten and clarified, comments
and details on section 4 added, acknowledgements rectified. To appear in JHE
Molecular mechanisms of cell death: recommendations of the Nomenclature Committee on Cell Death 2018.
Over the past decade, the Nomenclature Committee on Cell Death (NCCD) has formulated guidelines for the definition and interpretation of cell death from morphological, biochemical, and functional perspectives. Since the field continues to expand and novel mechanisms that orchestrate multiple cell death pathways are unveiled, we propose an updated classification of cell death subroutines focusing on mechanistic and essential (as opposed to correlative and dispensable) aspects of the process. As we provide molecularly oriented definitions of terms including intrinsic apoptosis, extrinsic apoptosis, mitochondrial permeability transition (MPT)-driven necrosis, necroptosis, ferroptosis, pyroptosis, parthanatos, entotic cell death, NETotic cell death, lysosome-dependent cell death, autophagy-dependent cell death, immunogenic cell death, cellular senescence, and mitotic catastrophe, we discuss the utility of neologisms that refer to highly specialized instances of these processes. The mission of the NCCD is to provide a widely accepted nomenclature on cell death in support of the continued development of the field
2nd Hyperpolarizabilities and Static and Optical-Frequency Polarizability Anisotropies of Benzene, 1,3,5-Trifluorobenzene, and Hexafluorobenzene
Formulation and physical characterization of microemulsions containing isotretinoin
Physical properties of microemulsions containing tween80 as surfactant and tetraglycol as cosurfactant, were investigated for their potential to form microemulsion templates as drug delivery vehicles for isotretinoin. Bile salt was used as edge activator in skin permeation and surfactant protein B (SP-B1-25) may be helpful in drug delivery and reducing sebum level. All of the compounds used to formulate the microemulsions were pharmaceutically acceptable and biocompatible. The drug-containing systems were characterized in regard to their transdermal parameters. Physiologically well-tolerated and physically stable multiple-component systems were developed. The concentrations of surfactants and cosurfactants which are necessary to form stable systems were evaluated. Microemulsions were characterized using polarized light microscopy, photon correlation spectroscopy (PCS), electric conductivity and rheometry. The influence of isotretinoin on the physical parameters of the preparation was investigated
Molecular Quadrupole-Moment and Effective-Quadrupole-Centre of Fluorobenzene
Measurements of the infinite-dilution molar field-gradient birefringence constant, Kerr constant and Cotton-Mouton constant of fluorobenzene as a solute in carbon tetrachloride at 25°C and at two visible-spectrum wavelengths (441.6 and 632.8 nm) are reported. Analysis of the observations, in conjunction with other known electric and magnetic properties of fluorobenzene, yields the out-of-plane component of the molecular quadrupole moment relative to the effective-quadrupole-centre, establishes that at both wavelengths the effective-quadrupole-centre is close to the centre-of-ring, and permits the evaluation of a combination of elements of the dipole-qudrupole polarizability, A, and the optical-activity tensor, GâČ. A complete, although approximate, specification of the centre-of-mass quadrupole moment can be obtained by invoking reasoning due to Shoemaker and Flygare; the result (Î/10 C m, Î/10 C m, Î/10 C m) now found (-1.5 ± 2.9, 22.5 ± 2.7, -21.0 ± 1.0) is at variance with that from the microwave Zeeman effect of this molecule (-6.3 ± 2.7, 17.0 ± 5.0, -10.7 ± 5.0)
Kerr Effects, Rayleigh Depolarization Ratios, Polarizabilities, and Hyperpolarizabilities of Fluorobenzene and Pentafluorobenzene
Field-Gradient-Induced Birefringence in Dilute-Solutions of Furan, Thiophene and Selenophen in Cyclohexane
Measurements of the infinite-dilution molar field-gradient birefringence constants, Kerr constants and Cotton-Mouton constants of furan, thiophen and selenophen as solutes in cyclohexane at 298 K and 632.8 nm are reported. Analysis of the observations, in conjunction with other known electric and magnetic properties of these molecules, yields for each the out-of-plane component of the quadrupole moment relative to the effective-quadrupole-centre. Combination of these results with centre-of-mass quadrupole moments from microwave Zeeman spectroscopic studies leads to low-precision estimates of the position of the effective-quadrupole-centre and of the relevant combination of elements of the A and GâČ tensors
Atomic force microscopy studies of Bowen Basin coal macerals
The porous structure of Bowen Basin coal macerals is very important in the storage and transport of coal seam gases. As part of a full characterization of this porosity, several coal macerals were examined by atomic force microscopy. Mesopores of greater than or equal to 8 nm deriving from different types of porosity were imaged. The pores were either formed by contact points between spherical clusters of molecules or were defined channels that had been created by some physical process. The potential of this technique for characterizing the porous structure in greater depth was demonstrated. (C) 1997 Elsevier Science Ltd
Rigid films of an anionic porphyrin and a dialkyl chain surfactant
The 2D complex formed at the air-water interface between the dialkyl chain cationic surfactant, dihexadecyldimethylammonium bromide, and the anionic porphyrin, tetrakis-(4-sulfonatophenyl) porphine, was studied using surface pressure-area isotherms as well as X-ray and neutron reflection measurements. The surface structure of these films was determined by the use of simultaneously constrained analysis of the neutron and X-ray reflectometry data and BAM images. Isotopic contrast variation methods were employed to enhance the information content of the neutron reflection data. The rigid complex forms at the interface due to the electrostatic interaction between the cationic headgroups of the surfactant and the anionic functional groups at the meso position of the porphyrin. The surface pressure-area isotherms show three distinct regions on compression: an initial condensed phase that ends with a pressure peak at 36 mN m(-1), a second plateau region of high compressibility, and a final condensed phase. BAM images show that at the beginning of the plateau region in the isotherm there is complete surface coverage by a monolayer. The constrained simultaneous fitting of neutron and X-ray data measured just prior to and after the pressure peak shows a structurally similar 2D complex at the interface. Modeling of X-ray reflectometry data also reveals that in the final high-pressure phase the film has folded to form a trilayer. The conclusion is that the plateau region of the isotherm is due to the formation of trilayer surface coverage through localized buckling or folding, and that after this is complete there is some condensation before final film collapse