19 research outputs found
Molecular modelling of odd viscoelastic fluids
We consider an active, stochastic microscopic model of particles suspended in
a fluid and show that the coarse-grained description of this model renders odd
viscoelasticity. The model is made up of odd dumbbells, each featuring a
robotic device as the bead, which exhibits a particular torque response. We
analytically compute the stress-stress correlator and corroborate the results
using molecular dynamics simulations. We also provide a unified analytical
framework for several experimental and numerical setups designed to elucidate
odd effects in fluids.Comment: 17 pages, 7 figure
Bose-Hubbard realization of fracton defects
Bose-Hubbard models are simple paradigmatic lattice models used to study
dynamics and phases of quantum bosonic matter. We combine the extended
Bose-Hubbard model in the hard-core regime with ring-exchange hoppings. By
investigating the symmetries and low-energy properties of the Hamiltonian we
argue that the model hosts fractonic defect excitations. We back up our claims
with exact numerical simulations of defect dynamics exhibiting mobility
constraints. Moreover, we confirm the robustness of our results against fracton
symmetry breaking perturbations. Finally we argue that this model can be
experimentally realized in recently proposed quantum simulator platforms with
big time crystals, thus paving a way for the controlled study of many-body
dynamics with mobility constraints.Comment: 12 pages, 7 figure
Quantum Hall effective action for anisotropic Dirac semi-metal
We present a study of Hall transport in semi-Dirac critical phases. The
construction is based on a covariant formulation of relativistic systems with
spatial anisotropy. Geometric data together with external electromagnetic
fields is used to devise an expansion procedure that leads to a low-energy
effective action consistent with the discrete symmetry that we impose. We
use the action to discuss terms contributing to the Hall transport and extract
the coefficients. We also discuss the associated scaling symmetry.Comment: 6 pages + supplementary material, 1 figur
Hydrodynamics of plastic deformations in electronic crystals
We construct a new hydrodynamic framework describing plastic deformations in
electronic crystals. The framework accounts for pinning, phase, and momentum
relaxation effects due to translational disorder, diffusion due to the presence
of interstitials and vacancies, and strain relaxation due to plasticity and
dislocations. We obtain the hydrodynamic mode spectrum and correlation
functions in various regimes in order to identify the signatures of plasticity
in electronic crystal phases. In particular, we show that proliferation of
dislocations de-pins the spatially resolved conductivity until the crystal
melts, after which point a new phase of a pinned electronic liquid emerges. In
addition, the mode spectrum exhibits a competition between pinning and
plasticity effects, with the damping rate of some modes being controlled by
pinning-induced phase relaxation and some by plasticity-induced strain
relaxation. We find that the recently discovered damping-attenuation relation
continues to hold for pinned-induced phase relaxation even in the presence of
plasticity and dislocations. We also comment on various experimental setups
that could probe the effects of plasticity. The framework developed here is
applicable to a large class of physical systems including electronic Wigner
crystals, multicomponent charge density waves, and ordinary crystals.Comment: v1: 34pp, 7fig
Probe particles in odd active viscoelastic fluids:How activity and dissipation determine linear stability
Odd viscoelastic materials are constrained by fewer symmetries than their even counterparts. The breaking of these symmetries allows these materials to exhibit different features, which have attracted considerable attention in recent years. Immersing a bead in such complex fluids allows for probing their physical properties, highlighting signatures of their oddity and exploring the consequences of these broken symmetries. We present the conditions under which the activity of an odd viscoelastic fluid can give rise to linear instabilities in the motion of the probe particle, and we unveil how the features of the probe particle dynamics depend on the oddity and activity of the viscoelastic medium in which it is immersed.</p
Probe particles in odd active viscoelastic fluids: how activity and dissipation determine linear stability
Odd viscoelastic materials are constrained by fewer symmetries than their
even counterparts. The breaking of these symmetries allow these materials to
exhibit different features, which have attracted considerable attention in
recent years. Immersing a bead in such complex fluids allows for probing their
physical properties, highlighting signatures of their oddity and exploring
consequences of these broken symmetries. We present the conditions under which
the activity of an odd viscoelastic fluid can give rise to linear instabilities
in the motion of the probe particle and unveil how the features of the probe
particle dynamics depend on the oddity and activity of the viscoelastic medium
in which it is immersed
Cationic iron porphyrins with sodium dodecyl sulphate for micellar catalysis of cyclopropanation reactions
Here, we report that the combination of cationic iron porphyrins with sodium dodecyl sulphate (SDS) gives rise to efficient micellar catalysis of cyclopropanation reactions of styrene derivatives, using diazoacetates as carbene precursors. This simple, yet effective approach for cyclopropanations illustrates the power of micellar catalysis
A Novel Method for Holographic Transport
We introduce a novel and effective method to compute transport coefficients in strongly interacting plasma states in holographic QFTs. Our method is based on relating the IR limit of fluctuations on a gravitational background to its variations providing a previously overlooked connection between boundary and near horizon data. We use this method to derive analytic formulas for the viscosities of an ansiotropic plasma state in the presence of an external magnetic field or another isotropy breaking external source. We then apply our findings to holographic QCD
Cancer Theranostic Dyes
Funding Information: This work was financed by national funds from FCT—Fundação para a Ciência e a Tecnologia, I.P., within the scope of the projects of the Ministry of Science Technology and Higher Education: UIDP/04378/2020 and UIDB/04378/2020 of the Research Unit on Applied Molecular Biosciences—UCIBIO and the project LA/P/0140/2020 of the Associate Laboratory Institute for Health and Bioeconomy—i4HB and, in part, by the Jeanne and J.-Louis Lévesque foundation, Montreal, QC, Canada (J.E.v.L.). J.E.v.L. is a member of the Research Center of the CHUS (CRCHUS), Sherbrooke, QC, Canada, supported by the Fonds de la Recherche du Québec—Santé. C.R.R., A.L. and R.V. were funded by FCT/MCTES, grant numbers SFRH/BPD/124612/2016, SFRH/BD/12161/2022, and SFRH/BD/09845/2022, respectively. Publisher Copyright: © 2023 by the authors.Estradiol-BODIPY linked via an 8-carbon spacer chain and 19-nortestosterone- and testosterone-BODIPY linked via an ethynyl spacer group were evaluated for cell uptake in the breast cancer cell lines MCF-7 and MDA-MB-231 and prostate cancer cell lines PC-3 and LNCaP, as well as in normal dermal fibroblasts, using fluorescence microscopy. The highest level of internalization was observed with 11β-OMe-estradiol-BODIPY 2 and 7α-Me-19-nortestosterone-BODIPY 4 towards cells expressing their specific receptors. Blocking experiments showed changes in non-specific cell uptake in the cancer and normal cells, which likely reflect differences in the lipophilicity of the conjugates. The internalization of the conjugates was shown to be an energy-dependent process that is likely mediated by clathrin- and caveolae-endocytosis. Studies using 2D co-cultures of cancer cells and normal fibroblasts showed that the conjugates are more selective towards cancer cells. Cell viability assays showed that the conjugates are non-toxic for cancer and/or normal cells. Visible light irradiation of cells incubated with estradiol-BODIPYs 1 and 2 and 7α-Me-19-nortestosterone-BODIPY 4 induced cell death, suggesting their potential for use as PDT agents.publishersversionpublishe