1,417 research outputs found
Altered connectivity of the right anterior insula drives the pain connectome changes in chronic knee osteoarthritis
Resting-state functional connectivity (FC) has proven a powerful approach to understand the neural underpinnings of chronic pain, reporting altered connectivity in three main networks: the default mode (DMN), central executive (CEN), and the salience network (SN). The interrelation and possible mechanisms of these changes are less well understood in chronic pain. Based on emerging evidence of its role to drive switches between network states, the right anterior insula (rAI, an SN hub) may play a dominant role in network connectivity changes underpinning chronic pain. To test this hypothesis, we used seed-based resting-state FC analysis including dynamic and effective connectivity metrics in 25 people with chronic osteoarthritis (OA) pain and 19 matched healthy volunteers. Compared to controls, participants with painful knee OA presented with increased anticorrelation between the right anterior insula (SN) and DMN regions. Also, the left dorsal prefrontal cortex (CEN hub) showed more negative FC with the right temporal gyrus. Granger causality analysis revealed increased negative influence of the right anterior insula on the posterior cingulate (DMN) in OA patients in line with the observed enhanced anticorrelation. Moreover, dynamic FC was lower in the DMN of patients and thus more similar to temporal dynamics of the SN. Together, these findings evidence a widespread network disruption in patients with persistent osteoarthritis pain, and point toward a driving role of the rAI
Manganese-enhanced magnetic resonance imaging depicts brain activity in models of acute and chronic pain: a new window to study experimental spontaneous pain?
Application of functional imaging techniques to animal models is vital to understand pain mechanisms, but is often confounded by the need to limit movement artefacts with anaesthesia, and a focus on evoked responses rather than clinically relevant spontaneous pain and related hyperalgesia. The aim of the present study was to investigate the potential of manganese-enhanced magnetic resonance imaging (MEMRI) to measure neural responses during on-going pain that underpins hyperalgesia in pre-clinical models of nociception. As a proof of concept that MEMRI is sensitive to the neural activity of spontaneous, intermittent behaviour, we studied a separate positive control group undergoing a voluntary running wheel experiment.
In the pain models, pain behaviour (weight bearing asymmetry and hindpaw withdrawal thresholds (PWTs)) was measured at baseline and following either intra-articular injection of nerve growth factor (NGF, 10 µg/50 µl; acute pain model, n=4 rats per group), or the chondrocyte toxin monosodium iodoacetate (MIA, 1 mg/50 µl; chronic model, n=8 rats per group), or control injection. Separate groups of rats underwent a voluntary wheel running protocol (n=8 rats per group). Rats were administered with paramagnetic ion Mn2+ as soluble MnCl2 over seven days (subcutaneous osmotic pump) to allow cumulative activity-dependent neural accumulation in the models of pain, or over a period of running. T1-weighted MR imaging at 7 T was performed under isoflurane anaesthesia using a receive-only rat head coil in combination with a 72 mm volume coil for excitation.
The pain models resulted in weight bearing asymmetry (NGF: 20.0 ± 5.2%, MIA: 15 ± 3%), and a reduction in PWT in the MIA model (8.3 ± 1.5 g) on the final day of assessment before undergoing MR imaging. Voxel-wise and region-based analysis of MEMRI data did not identify group differences in T1 signal. However, MnCl2 accumulation in the VTA, right Ce amygdala, and left cingulate was negatively correlated with pain responses (greater differences in weight bearing), similarly MnCl2 accumulation was reduced in the VTA in line with hyperalgesia (lower PWTs), which suggests reduced regional activation as a result of the intensity and duration of pain experienced during the 7 days of MnCl2 exposure. Motor cortex T1-weighted signal increase was associated with the distance ran in the wheel running study, while no between group difference was seen. Our data suggest that on-going pain related signal changes identified using MEMRI offers a new window to study the neural underpinnings of spontaneous pain in rats
Multiplication and Composition in Weighted Modulation Spaces
We study the existence of the product of two weighted modulation spaces. For
this purpose we discuss two different strategies. The more simple one allows
transparent proofs in various situations. However, our second method allows a
closer look onto associated norm inequalities under restrictions in the Fourier
image. This will give us the opportunity to treat the boundedness of
composition operators.Comment: 49 page
Search for CP Violation in the Decays
We have searched for CP violation in the decays
where denotes a neutral pseudo-scalar meson which is either a ,
, or using KEKB asymmetric-energy collision data
corresponding to an integrated luminosity of 791 fb collected with the
Belle detector. No evidence of significant CP violation is observed. We report
the most precise CP asymmetry measurement in the decay to date: . We also report the first measurements of
CP asymmetries in the decays and : and , respectively
Effect of intersubband scattering on weak localization in 2D systems
The theory of weak localization is generalized for multilevel 2D systems
taking into account intersubband scattering. It is shown that weak intersubband
scattering which is negligible in a classical transport, affects strongly the
weak-localization correction to conductivity. The anomalous magnetoresistance
is calculated in the whole range of classically low magnetic fields. This
correction to conductivity is shown to depend strongly on the ratios of
occupied level concentrations. It is demonstrated that at relatively low
population of the excited subband, it is necessary to use the present theory
because the high-field limit asimptotics is shown to be achieved only in
classical magnetic fields.Comment: 18 pages, 4 figures. Accepted to Phys. Rev. B 6
Search for double charmonium decays of the P-wave spin-triplet bottomonium states
Using a sample of 158 million events collected with the Belle
detector, we search for the first time for double charmonium decays of the
-wave spin-triplet bottomonium states (,
\chi_{bJ} \to \jpsi \jpsi, \jpsi \psp, \psp \psp for J=0, 1, and 2). No
significant signal is observed in the double charmonium mass
spectra, and we obtain the following upper limits, \BR(\chi_{bJ} \to \jpsi
\jpsi)<7.1\times 10^{-5}, , ,
\BR(\chi_{bJ} \to \jpsi \psp)<1.2\times 10^{-4}, ,
, \BR(\chi_{bJ} \to \psp \psp)<3.1\times 10^{-5},
, for J=0, 1, and 2, respectively, at
the 90% confidence level. These limits are significantly lower than the central
values (with uncertainties of 50% to 70%) predicted using the light cone
formalism but are consistent with calculations using the NRQCD factorization
approach.Comment: 7 pages, 4 figures, 1 tabl
Evidence for Direct CP Violation in and Observation of
We report measurements of the branching fractions and CP asymmetries for B^+-
-> eta h^+- (h = K or pi) and the observation of the decay B^0 -> eta K^0 from
the final data sample of 772x10^6 BBbar pairs collected with the Belle detector
at the KEKB asymmetric-energy e^+e^- collider. The measured branching fractions
are Br(B^+- -> eta K^+-) = (2.12 +- 0.23 +- 0.11)x10^-6}, Br(B^+- -> eta pi^+-)
= (4.07 +- 0.26 +- 0.21)x10^{-6} and Br(B^0 -> eta K^0) = (1.27^{+0.33}_{-0.29}
+- 0.08)x10^-6, where the last decay is observed for the first time with a
significance of 5.4 standard deviations (\sigma). We also find evidence for CP
violation in the charged B modes, A_{CP}(B^+- -> eta K^+-) = -0.38 +- 0.11 +-
0.01 and A_{CP}(B^+- -> eta pi^+- = -0.19 +- 0.06 +- 0.01 with significances of
3.8 sigma and 3.0 sigma, respectively. For all measurements, the first and
second uncertainties are statistical and systematic, respectively.Comment: 6 pages, 3 figures, 1 tabl
Observation of and search for in B decays
We report a study of and
decay modes using events collected at the
\Upsilon(4S)e^+ e^-X(3872) \to J/\psi \gamma\chi_{c2} \to J/\psi \gammaB\to (X_{c\bar{c}}\gamma) KX(3872) \to \psi' \gamma\mathcal{B}(B^{\pm} \to X(3872)
K^{\pm}) \mathcal{B}(X(3872) \to J/\psi\gamma)=(1.78^{+0.48}_{-0.44}\pm
0.12)\times 10^{-6}\mathcal{B} (B^{\pm} \to\chi_{c2} K^{\pm})=(1.11^{+0.36}_{-0.34} \pm 0.09) \times 10^{-5}\mathcal{B}(B^{\pm} \to
X(3872) K^{\pm}) \mathcal{B}(X(3872) \to \psi'\gamma)<3.45\times 10^{-6}$
(upper limit at 90% C.L.) and also provide upper limits for other searches.Comment: 6 pages, 3 figure
- …
