8,503 research outputs found
Identifying a core set of outcome domains to measure in clinical trials for shoulder disorders: a modified Delphi study.
OBJECTIVE: To achieve consensus on the most important outcome domains to measure across all clinical trials for shoulder disorders. METHODS: We performed an online modified Delphi study with an international, multidisciplinary and multistakeholder panel. A literature review and the OMERACT Filter 2.0 framework was used to generate a list of potential core domains, which were presented to patients, clinicians and researchers in two Delphi rounds. Participants were asked to judge the importance of each potential core domain and provide a rationale for their response. A core domain was defined a priori as a domain that at least 67% of participants considered core. RESULTS: In both rounds, 335 individuals were invited to participate (268 clinicians/researchers and 67 patients); response rates were 27% (n=91) and 29% (n=96), respectively. From a list of 41 potential core domains, four domains met our criteria for inclusion: 'pain', 'physical functioning', 'global assessment of treatment success' and 'health-related quality of life'. Two additional domains, 'sleep functioning' and 'psychological functioning', met the criteria for inclusion by some, but not all stakeholder groups. There was consensus that 'number of deaths' was not a core domain, but insufficient agreement on whether or not several other domains, including 'range of motion' and 'muscle strength', were core domains. CONCLUSIONS: Based on international consensus from patients, clinicians and researchers, 'pain', 'physical functioning', 'global assessment of treatment success' and 'health-related quality of life' were considered core outcome domains for shoulder disorder trials. The value of several other domains needs further consideration
Emergent excitations in a geometrically frustrated magnet
Frustrated systems are ubiquitous and interesting because their behavior is
difficult to predict. Magnetism offers extreme examples in the form of spin
lattices where all interactions between spins cannot be simultaneously
satisfied. Such geometrical frustration leads to macroscopic degeneracies, and
offers the possibility of qualitatively new states of matter whose nature has
yet to be fully understood. Here we have discovered how novel composite spin
degrees of freedom can emerge from frustrated interactions in the cubic spinel
ZnCr2O4. Upon cooling, groups of six spins self-organize into weakly
interacting antiferromagnetic loops whose directors, defined as the unique
direction along which the spins are aligned parallel or antiparallel, govern
all low temperature dynamics. The experimental evidence comes from a
measurement of the magnetic form factor by inelastic neutron scattering. While
the data bears no resemblance to the atomic form factor for chromium, they are
perfectly consistent with the form factor for hexagonal spin loop directors.
The hexagon directors are to a first approximation decoupled from each other
and hence their reorientations embody the long-sought local zero energy modes
for the pyrochlore lattice.Comment: 10 pages, 4 figures upon reques
Two-dimensional amine and hydroxy functionalized fused aromatic covalent organic framework
Ordered two-dimensional covalent organic frameworks (COFs) have generally been synthesized using reversible reactions. It has been difficult to synthesize a similar degree of ordered COFs using irreversible reactions. Developing COFs with a fused aromatic ring system via an irreversible reaction is highly desirable but has remained a significant challenge. Here we demonstrate a COF that can be synthesized from organic building blocks via irreversible condensation (aromatization). The as-synthesized robust fused aromatic COF (F-COF) exhibits high crystallinity. Its lattice structure is characterized by scanning tunneling microscopy and X-ray diffraction pattern. Because of its fused aromatic ring system, the F-COF structure possesses high physiochemical stability, due to the absence of hydrolysable weak covalent bonds
Quantum spin liquid states in the two dimensional kagome antiferromagnets, ZnxCu4-x(OD)6Cl2
A three-dimensional system of interacting spins typically develops static
long-range order when it is cooled. If the spins are quantum (S = 1/2),
however, novel quantum paramagnetic states may appear. The most highly sought
state among them is the resonating valence bond (RVB) state in which every pair
of neighboring quantum spins form entangled spin singlets (valence bonds) and
the singlets are quantum mechanically resonating amongst all the possible
highly degenerate pairing states. Here we provide experimental evidence for
such quantum paramagnetic states existing in frustrated antiferromagnets,
ZnxCu4-x(OD)6Cl2, where the S = 1/2 magnetic Cu2+ moments form layers of a
two-dimensional kagome lattice. We find that in Cu4(OD)6Cl2, where distorted
kagome planes are weakly coupled to each other, a dispersionless excitation
mode appears in the magnetic excitation spectrum below ~ 20 K, whose
characteristics resemble those of quantum spin singlets in a solid state, known
as a valence bond solid (VBS), that breaks translational symmetry. Doping
nonmagnetic Zn2+ ions reduces the distortion of the kagome lattice, and weakens
the interplane coupling but also dilutes the magnetic occupancy of the kagome
lattice. The VBS state is suppressed and for ZnCu3(OD)6Cl2 where the kagome
planes are undistorted and 90% occupied by the Cu2+ ions, the low energy spin
fluctuations in the spin liquid phase become featureless
Machine-learning of atomic-scale properties based on physical principles
We briefly summarize the kernel regression approach, as used recently in
materials modelling, to fitting functions, particularly potential energy
surfaces, and highlight how the linear algebra framework can be used to both
predict and train from linear functionals of the potential energy, such as the
total energy and atomic forces. We then give a detailed account of the Smooth
Overlap of Atomic Positions (SOAP) representation and kernel, showing how it
arises from an abstract representation of smooth atomic densities, and how it
is related to several popular density-based representations of atomic
structure. We also discuss recent generalisations that allow fine control of
correlations between different atomic species, prediction and fitting of
tensorial properties, and also how to construct structural kernels---applicable
to comparing entire molecules or periodic systems---that go beyond an additive
combination of local environments
Hidden SUSY at the LHC: the light higgsino-world scenario and the role of a lepton collider
While the SUSY flavor, CP and gravitino problems seem to favor a very heavy
spectrum of matter scalars, fine-tuning in the electroweak sector prefers low
values of superpotential mass \mu. In the limit of low \mu, the two lightest
neutralinos and light chargino are higgsino-like. The light charginos and
neutralinos may have large production cross sections at LHC, but since they are
nearly mass degenerate, there is only small energy release in three-body
sparticle decays. Possible dilepton and trilepton signatures are difficult to
observe after mild cuts due to the very soft p_T spectrum of the final state
isolated leptons. Thus, the higgsino-world scenario can easily elude standard
SUSY searches at the LHC. It should motivate experimental searches to focus on
dimuon and trimuon production at the very lowest p_T(\mu) values possible. If
the neutralino relic abundance is enhanced via non-standard cosmological dark
matter production, then there exist excellent prospects for direct or indirect
detection of higgsino-like WIMPs. While the higgsino-world scenario may easily
hide from LHC SUSY searches, a linear e^+e^- collider or a muon collider
operating in the \sqrt{s}\sim 0.5-1 TeV range would be able to easily access
the chargino and neutralino pair production reactions.Comment: 20 pages including 12 .eps figure
Nanodiamonds as Carriers for Address Delivery of Biologically Active Substances
Surface of detonation nanodiamonds was functionalized for the covalent attachment of immunoglobulin, and simultaneously bovine serum albumin and Rabbit Anti-Mouse Antibody. The nanodiamond-IgGI125 and RAM-nanodiamond-BSAI125 complexes are stable in blood serum and the immobilized proteins retain their biological activity. It was shown that the RAM-nanodiamond-BSAI125 complex is able to bind to the target antigen immobilized on the Sepharose 6B matrix through antibody–antigen interaction. The idea can be extended to use nanodiamonds as carriers for delivery of bioactive substances (i.e., drugs) to various targets in vivo
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Multiple targets for flecainide action: implications for cardiac arrhythmogenesis
Flecainide suppresses cardiac tachyarrhythmias including paroxysmal atrial fibrillation, supraventricular tachycardia and arrhythmic long QT syndromes (LQTS), as well as the Ca(2+) -mediated, catecholaminergic polymorphic ventricular tachycardia (CPVT). However, flecainide can also exert pro-arrhythmic effects most notably following myocardial infarction and when used to diagnose Brugada syndrome (BrS). These divergent actions result from its physiological and pharmacological actions at multiple, interacting levels of cellular organization. These were studied in murine genetic models with modified Nav channel or intracellular ryanodine receptor (RyR2)-Ca(2+) channel function. Flecainide accesses its transmembrane Nav 1.5 channel binding site during activated, open, states producing a use-dependent antagonism. Closing either activation or inactivation gates traps flecainide within the pore. An early peak INa related to activation of Nav channels followed by rapid de-activation, drives action potential (AP) upstrokes and their propagation. This is diminished in pro-arrhythmic conditions reflecting loss of function of Nav 1.5 channels, such as BrS, accordingly exacerbated by flecainide challenge. Contrastingly, pro-arrhythmic effects attributed to prolonged AP recovery by abnormal late INaL following gain-of-function modifications of Nav 1.5 channels in LQTS3 are reduced by flecainide. Anti-arrhythmic effects of flecainide that reduce triggering in CPVT models mediated by sarcoplasmic reticular Ca(2+) release could arise from its primary actions on Nav channels indirectly decreasing [Ca(2+) ]i through a reduced [Na(+) ]i and/or direct open-state RyR2-Ca(2+) channel antagonism. The consequent [Ca(2+) ]i alterations could also modify AP propagation velocity and therefore arrhythmic substrate through its actions on Nav 1.5 channel function. This is consistent with the paradoxical differences between flecainide actions upon Na(+) currents, AP conduction and arrhythmogenesis under circumstances of normal and increased RyR2 function.S.C.S. and A.P.J. are funded by the British Heart Foundation (PG/14/79/31102). K.J. is funded by the Fundamental Research Grant Scheme (FRGS/2/2014/SKK01/PERDANA/ 02/1), Ministry of Education, Malaysia and the Research Support Fund, Faculty of Health and Medical Science, University of Surrey. A.F.D. is funded by the National Health and Medical Research Council (NHMRC) of Australia (APP1126201). A.J.T. is funded by the British Heart Foundation (PG/13/39/3029). C.L.H.H. is funded by the Medical Research Council (MR/M001288/1), Wellcome Trust (105727/Z/14/Z), British Heart Foundation (PG/14/79/ 31102), the McVeigh Benefaction and SADS UK
A photonic quantum information interface
Quantum communication is the art of transferring quantum states, or quantum
bits of information (qubits), from one place to another. On the fundamental
side, this allows one to distribute entanglement and demonstrate quantum
nonlocality over significant distances. On the more applied side, quantum
cryptography offers, for the first time in human history, a provably secure way
to establish a confidential key between distant partners. Photons represent the
natural flying qubit carriers for quantum communication, and the presence of
telecom optical fibres makes the wavelengths of 1310 and 1550 nm particulary
suitable for distribution over long distances. However, to store and process
quantum information, qubits could be encoded into alkaline atoms that absorb
and emit at around 800 nm wavelength. Hence, future quantum information
networks made of telecom channels and alkaline memories will demand interfaces
able to achieve qubit transfers between these useful wavelengths while
preserving quantum coherence and entanglement. Here we report on a qubit
transfer between photons at 1310 and 710 nm via a nonlinear up-conversion
process with a success probability greater than 5%. In the event of a
successful qubit transfer, we observe strong two-photon interference between
the 710 nm photon and a third photon at 1550 nm, initially entangled with the
1310 nm photon, although they never directly interacted. The corresponding
fidelity is higher than 98%.Comment: 7 pages, 3 figure
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