16,700 research outputs found
Thermalization and Cooling of Plasmon-Exciton Polaritons: Towards Quantum Condensation
We present indications of thermalization and cooling of quasi-particles, a
precursor for quantum condensation, in a plasmonic nanoparticle array. We
investigate a periodic array of metallic nanorods covered by a polymer layer
doped with an organic dye at room temperature. Surface lattice resonances of
the array---hybridized plasmonic/photonic modes---couple strongly to excitons
in the dye, and bosonic quasi-particles which we call
plasmon-exciton-polaritons (PEPs) are formed. By increasing the PEP density
through optical pumping, we observe thermalization and cooling of the strongly
coupled PEP band in the light emission dispersion diagram. For increased
pumping, we observe saturation of the strong coupling and emission in a new
weakly coupled band, which again shows signatures of thermalization and
cooling.Comment: 8 pages, 5 figures including supplemental material. The newest
version includes new measurements and corrections to the interpretation of
the result
Design and fabrication of chemically robust three-dimensional microfluidic valves
A current problem in microfluidics is that poly(dimethylsiloxane) (PDMS), used to fabricate many microfluidic devices, is not compatible with most organic solvents. Fluorinated compounds are more chemically robust than PDMS but, historically, it has been nearly impossible to construct valves out of them by multilayer soft lithography (MSL) due to the difficulty of bonding layers made of non-stick fluoropolymers necessary to create traditional microfluidic valves. With our new three-dimensional (3D) valve design we can fabricate microfluidic devices from fluorinated compounds in a single monolithic layer that is resistant to most organic solvents with minimal swelling. This paper describes the design and development of 3D microfluidic valves by molding of a perfluoropolyether, termed Sifel, onto printed wax molds. The fabrication of Sifel-based microfluidic devices using this technique has great potential in chemical synthesis and analysis
Industrial manufacturing and characterization of multiscale CFRP laminates made from prepregs containing graphene-related materials
The introduction of graphene-related materials (GRMs) in carbon
fibre-reinforced polymers (CFRP) has been proved to enhance their mechanical
and electrical properties. However, methodologies to produce the 3-phase
materials (multiscale composites) at an industrial scale and in an efficient
manner are still lacking. In this paper, multiscale CFRP composites containing
different GRMs have been manufactured following standard procedures currently
used in the aerospace industry with the aim to evaluate its potential
application. Graphite nanoplateletelets (GNPs), in situ exfoliated graphene
oxide (GO) and reduced graphene oxide (rGO) have been dispersed into an epoxy
resin to subsequently impregnate aeronautical grade carbon fibre tape. The
resulting prepregs have been used for manufacturing laminates by hand lay-up
and autoclave curing at 180 {\deg}C. Abroad characterization campaign has been
carried out to understand the behaviour of the different multiscale laminates
manufactured. The degree of cure, glass transition temperature and degradation
temperature have been evaluated by thermal evolution techniques. Similarly,
their mechanical properties (tensile, flexural, in-plane shear, interlaminar
shear and mode I interlaminar fracture toughness) have been analysed together
with their electrical conductivity. The manufacturing process resulted
appropriated for producing three-phase laminates and their quality was as good
as in conventional CFRPs. The addition ofGOand rGO resulted in an enhancement
of the in-plane shear properties and delamination resistance while the addition
ofGNPimproved the electrical conductivity
Lower Cretaceous (Hauterivian-Albian) ammonite biostratigraphy in the Maestrat Basin (E Spain)
Peer reviewedPublisher PD
hMOB2 deficiency impairs homologous recombination-mediated DNA repair and sensitises cancer cells to PARP inhibitors
Monopolar spindle-one binder (MOBs) proteins are evolutionarily conserved and contribute to various cellular signalling pathways. Recently, we reported that hMOB2 functions in preventing the accumulation of endogenous DNA damage and a subsequent p53/p21-dependent G1/S cell cycle arrest in untransformed cells. However, the question of how hMOB2 protects cells from endogenous DNA damage accumulation remained enigmatic. Here, we uncover hMOB2 as a regulator of double-strand break (DSB) repair by homologous recombination (HR). hMOB2 supports the phosphorylation and accumulation of the RAD51 recombinase on resected single-strand DNA (ssDNA) overhangs. Physiologically, hMOB2 expression supports cancer cell survival in response to DSB-inducing anti-cancer compounds. Specifically, loss of hMOB2 renders ovarian and other cancer cells more vulnerable to FDA-approved PARP inhibitors. Reduced MOB2 expression correlates with increased overall survival in patients suffering from ovarian carcinoma. Taken together, our findings suggest that hMOB2 expression may serve as a candidate stratification biomarker of patients for HR-deficiency targeted cancer therapies, such as PARP inhibitor treatments
Structure, Atomistic Simulations, and Phase Transition of Stoichiometric Yeelimite
ABSTRACT: Yeelimite, Ca4[Al6O12]SO4, is outstanding as an aluminate
sodalite, being the framework of these type of materials flexible and dependent
on ion sizes and anion ordering/disordering. On the other hand, yeelimite is also
important from an applied perspective as it is the most important phase in
calcium sulfoaluminate cements. However, its crystal structure is not well
studied. Here, we characterize the room temperature crystal structure of
stoichiometric yeelimite through joint Rietveld refinement using neutron and Xray
powder diffraction data coupled with chemical soft-constraints. Our structural
study shows that yeelimite has a lower symmetry than that of the previously
reported tetragonal system, which we establish to likely be the acentric
orthorhombic space group Pcc2, with a √2a × √2a × a superstructure based on
the cubic sodalite structure. Final unit cell values were a = 13.0356(7) Å, b =
13.0350(7) Å, and c = 9.1677(2) Å. We determine several structures using
density functional theory calculations, with the lowest energy structure being Pcc2 in agreement with our experimental result.
Yeelimite undergoes a reversible phase transition to a higher-symmetry phase which has been characterized to occur at 470 °C by
thermodiffractometry. The higher-symmetry phase is likely cubic or pseudocubic possessing an incommensurate superstructure,
as suggested by our theoretical calculations which show a phase transition from an orthorhombic to a tetragonal structure. Our
theoretical study also predicts a pressure-induced phase transition to a cubic structure of space group I43m. Finally, we show that
our reported crystal structure of yeelimite enables better mineralogical phase analysis of commercial calcium sulfoaluminate
cements, as shown by RF values for this phase, 6.9% and 4.8% for the previously published orthorhombic structure and for the
one reported in this study, respectively.Universidad de Málaga. Campus de Excelencia Internacional. Andalucía Tech
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