7,212 research outputs found
The 2D/3D dynamics of wall-bounded low-Rm magnetohydrodynamic (MHD) turbulence
No full textWith this experimental study, we give evidence that the dynamics of low-Rm MHD turbulence depends on the diffusion length l_z, which corresponds to the distance over which the Lorentz force is able to diffuse momentum before it is balanced by inertia
Long Term Diabetes with Hypertension is Associated with a Down-Regulation of AT1 and AT2 Receptors in the Kidney: Effects of AT1 Receptor Antagonism
No full textPrecursory Cooper Flow in Ultralow-Temperature Superconductors
No full textSuperconductivity at low temperature -- observed in lithium and bismuth, as
well as in various low-density superconductors -- calls for developing reliable
theoretical and experimental tools for predicting ultralow critical
temperatures, , of Cooper instability in a system demonstrating nothing
but normal Fermi liquid behavior in a broad range of temperatures below the
Fermi energy, . Equally important are controlled predictions of
stability in a given Cooper channel. We identify such a protocol within the
paradigm of precursory Cooper flow -- a universal ansatz describing
logarithmically slow temperature evolution of the linear response of the normal
state to the pair-creating perturbation. Applying this framework to the
two-dimensional uniform electron gas, we reveal a series of exotic
superconducting states, pushing controlled theoretical predictions of to
the unprecedentedly low scale of
Enhanced cooling of neutron stars via Cooper-pairing neutrino emission
No full textWe simulate cooling of superfluid neutron stars with
nucleon cores where
the direct Urca process is forbidden. We adopt
density-dependent critical temperatures and
of singlet-state proton and triplet-state
neutron pairing in a stellar core and consider strong
proton pairing (with maximum T_{\rm cp}^{\rm max} \ga
5 \times 10^9 K) and moderate neutron pairing
( K).
When the internal stellar temperature T falls below
, the neutrino luminosity LCP
due to Cooper pairing of neutrons behaves
T8, just as that produced by the modified
Urca process (in a non-superfluid star)
but is higher by about two orders of magnitude.
In this case the Cooper-pairing neutrino emission acts
like an enhanced cooling agent. By tuning the density
dependence we can explain observations
of cooling isolated neutron stars in the scenario in which
the direct Urca
process or a similar process in kaon/pion condensed or
quark matter are absent.
Relaxation time of the Cooper pairs near
No full textIt is first shown that
the thermal fluctuation effects on the transport and on the thermodynamic
observables above the superconducting transition may provide, when they are
analyzed simultaneously and consistently, a powerful tool to access the relaxation
time, , of the Cooper pairs with wave vector in high-temperature
cuprate superconductors (HTSC). Then, we apply this procedure to optimally
doped
YBa2Cu3O (Y-123) crystals. It is found that in this HTSC follows, within
20% accuracy, the BCS temperature behaviour and amplitude given by
Synergistic activity of gamma-linolenic acid and cytotoxic drugs against pancreatic adenocarcinoma cell lines
No full textBackground: gamma-Linolenic acid (GLA) is growth inhibitory both in vitro and in vivo, at doses non-toxic to non-cancer cells. Chemotherapeutic agents have limited activity in pancreatic cancer. Interactions between GLA and cytotoxic drugs have not previously been investigated; any synergy might improve the therapeutic effect of these agents. Aim: To investigate possible interactions between GLA and 5-fluorouracil (5-FU) or gemcitabine against pancreatic cancer cell lines in vitro. Methods: Two pancreatic cancer cell lines were exposed to GLA alone and in combination with 5-FU or gemcitabine. Residual viable biomass was measured using the MTT assay and the results analysed by the median effect method of Chou and Talalay [Adv Enzyme Regul 1984;22:27-55]. Results: GLA concentrations of 3.9- 125 µg/ml had a synergistic or additive growth inhibitory effect on all tested concentrations of gemcitabine. Synergism was demonstrated between GLA and 5-FU only at concentrations of 62.5-125 µg/ml of 5-FU. Conclusion: GLA has a synergistic effect with gemcitabine at concentrations that correspond to in vivo therapeutic doses. GLA with 5-FU is synergistic only at a tight range of high concentrations of 5-FU. GLA lacks toxic side effects and may be useful in combination with gemcitabine
Etude expérimentale et théorique d'un transistor à flux de vortex réalisé sur couche mince supraconductrice à haute . Comparaison avec un interféromètre haut à boucles multiples
No full textThe theoretical and experimental behaviour of two magnetic field controlled superconducting structures both paterned in a YBaCuO thin film on MgO substrate are compared. One is based on the flux flow of Abrikosov vortices and the other one on the interferences between the wave functions of the Cooper pairs crossing high Josephson junctions connected by superconducting loops.Nous présentons une étude expérimentale et théorique de structures supraconductrices réalisées sur couches minces d'YBaCuO (déposées sur substrat de MgO) commandées en champ magnétique basées, l'une sur le mouvement de vortex Abrikosov, l'autre sur les interférences des fonctions d'onde des paires de Cooper traversant des jonctions Josephson HT connectées en parallèle
Dataset for paper :Maternal and fetal genetic variation in vitamin D metabolism and umbilical cord blood 25-hydroxyvitamin D - Supplemental Tables and Figures
No full textSupplemental tables and figures to accompany the paper "Maternal and fetal genetic variation in vitamin D metabolism and umbilical cord blood 25-hydroxyvitamin D" by RJ Moon, LDF Cooke, S D'Angelo, EM Curtis, P Titcombe, JH Davies, KM Godfrey, JK Cleal, RM Lewis, C Cooper & NC Harvey
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Highlights of the First International "Immunotherapy in Pediatric Oncology: Progress and Challenges" Meeting.
No full textThe first annual conference on immunotherapy in pediatric oncology was held in Bethesda, MD, from September 9 to 10, 2008 to discuss the state-of-the-art of immunotherapeutic strategies currently being explored in pediatric oncology. Major topics included targeting cell surface receptors, understanding and improving T-cell-based therapies, augmenting innate immune strategies, and enhancing graft-versus-leukemia for pediatric malignancies. As can be seen in the summaries of the individual presentations, significant progress has been made in developing preclinical models of pediatric tumors and a variety of novel immunobiologic therapies are approaching, or already in, the clinic. Although there is much excitement about the potential utility of these agents, a great deal of challenges lie ahead in improving the efficacy of each of these modalities and getting them to patients in a timely fashion. The resulting discussions will hopefully lead to new collaborations and insight for further translational and clinical studies
Triangular Constellations in Flows
No full textParticles advected on the surface of a fluid can exhibit fractal clustering. The local structure of a fractal set is described by its dimension , which is the exponent of a power-law relating the mass in a ball to its radius : . It is desirable to characterise the {\em shapes} of constellations of points sampling a fractal measure, as well as their masses. The simplest example is the distribution of shapes of triangles formed by triplets of points, which we investigate for fractals generated by chaotic dynamical systems. The most significant parameter describing the triangle shape is the ratio of its area to the radius of gyration squared. We show that the probability density of has a phase transition: is independent of and approximately uniform below a critical flow compressibility , which we estimate. For the distribution appears to be described by two power laws: when , and when
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