154 research outputs found
Strained graphene structures: from valleytronics to pressure sensing
Due to its strong bonds graphene can stretch up to 25% of its original size
without breaking. Furthermore, mechanical deformations lead to the generation
of pseudo-magnetic fields (PMF) that can exceed 300 T. The generated PMF has
opposite direction for electrons originating from different valleys. We show
that valley-polarized currents can be generated by local straining of
multi-terminal graphene devices. The pseudo-magnetic field created by a
Gaussian-like deformation allows electrons from only one valley to transmit and
a current of electrons from a single valley is generated at the opposite side
of the locally strained region. Furthermore, applying a pressure difference
between the two sides of a graphene membrane causes it to bend/bulge resulting
in a resistance change. We find that the resistance changes linearly with
pressure for bubbles of small radius while the response becomes non-linear for
bubbles that stretch almost to the edges of the sample. This is explained as
due to the strong interference of propagating electronic modes inside the
bubble. Our calculations show that high gauge factors can be obtained in this
way which makes graphene a good candidate for pressure sensing.Comment: to appear in proceedings of the NATO Advanced Research Worksho
A standardised study to compare prostate cancer targeting efficacy of five radiolabelled bombesin analogues
Purpose: Prostate-specific antigen (PSA)-based screening for prostate cancer (PC) has dramatically increased early diagnosis. Current imaging techniques are not optimal to stage early PC adequately. A promising alternative to PC imaging is peptide-based scintigraphy using radiolabelled bombesin (BN) analogues that bind to gastrin-releasing peptide receptors (GRPR) being overexpressed in PC. When labelled to appropriate radionuclides BN targeting of GRPRs may also provide applications for peptide radionuclide receptor therapy (PRRT). Assessment studies under identical experimental conditions allowing a reliable comparison of the potential of such analogues are lacking. This study was performed to evaluate and directly compare five promising radiolabelled BN analogues for their targeting efficacy for PC under standardised conditions. Methods: The BN agonists [111In]DOTA-PESIN, [111In]AMBA, [111In]MP2346 and [111In]MP2653 and one antagonist [99mTc]Demobesin-1 were evaluated in GRPR-overexpressing human PC-3 tumou
Prevalence of headache in Europe: a review for the Eurolight project
The main aim of the present study was to do an update on studies on headache epidemiology as a preparation for the multinational European study on the prevalence and burden of headache and investigate the impact of different methodological issues on the results. The study was based on a previous study, and a systematic literature search was performed to identify the newest studies. More than 50% of adults indicate that they suffer from headache in general during the last year or less, but when asked specifically about tension-type headache, the prevalence was 60%. Migraine occurs in 15%, chronic headache in about 4% and possible medication overuse headache in 1â2%. Cluster headache has a lifetime prevalence of 0.2â0.3%. Most headaches are more prevalent in women, and somewhat less prevalent in children and youth. Some studies indicate that the headache prevalence is increasing during the last decades in Europe. As to methodological issues, lifetime prevalences are in general higher than 1-year prevalences, but the exact time frame of headache (1Â year, 6 or 3Â months, or no time frame stated) seems to be of less importance. Studies using personal interviews seem to give somewhat higher prevalences than those using questionnaires
Synaptic Depression Via Mglur1 Positive Allosteric Modulation Suppresses Cue-Induced Cocaine Craving
Cue-induced cocaine craving is a major cause of relapse in abstinent addicts. In rats, cue-induced craving progressively intensifies (incubates) during withdrawal from extended-access cocaine self-administration. After ~1 month of withdrawal, incubated craving is mediated by Ca(2+)-permeable AMPA receptors (CP-AMPARs) that accumulate in the nucleus accumbens (NAc). We found that decreased mGluR1 surface expression in the NAc preceded and enabled CP-AMPAR accumulation. Thus, restoring mGluR1 transmission by administering repeated injections of an mGluR1 positive allosteric modulator (PAM) prevented CP-AMPAR accumulation and incubation, whereas blocking mGluR1 transmission at even earlier withdrawal times accelerated CP-AMPAR accumulation. In studies conducted after prolonged withdrawal, when CP-AMPAR levels and cue-induced craving are high, we found that systemic administration of an mGluR1 PAM attenuated the expression of incubated craving by reducing CP-AMPAR transmission in the NAc to control levels. These results suggest a strategy in which recovering addicts could use a systemically active compound to protect against cue-induced relapse
A comparison of bone density and bone morphology between patients presenting with hip fractures, spinal fractures or a combination of the two
Key signaling nodes in mammary gland development and cancer: ÎČ-catenin
ÎČ-Catenin plays important roles in mammary development and tumorigenesis through its functions in cell adhesion, signal transduction and regulation of cell-context-specific gene expression. Studies in mice have highlighted the critical role of ÎČ-catenin signaling for stem cell biology at multiple stages of mammary development. Deregulated ÎČ-catenin signaling disturbs stem and progenitor cell dynamics and induces mammary tumors in mice. Recent data showing deregulated ÎČ-catenin signaling in metaplastic and basal-type tumors suggest a similar link to reactivated developmental pathways and human breast cancer. The present review will discuss ÎČ-catenin as a central transducer of numerous signaling pathways and its role in mammary development and breast cancer
Test of lepton universality in decays
The first simultaneous test of muon-electron universality using
and decays is performed, in two ranges of the dilepton
invariant-mass squared, . The analysis uses beauty mesons produced in
proton-proton collisions collected with the LHCb detector between 2011 and
2018, corresponding to an integrated luminosity of 9 . Each
of the four lepton universality measurements reported is either the first in
the given interval or supersedes previous LHCb measurements. The
results are compatible with the predictions of the Standard Model.Comment: All figures and tables, along with any supplementary material and
additional information, are available at
https://cern.ch/lhcbproject/Publications/p/LHCb-PAPER-2022-046.html (LHCb
public pages
Precision measurement of violation in the penguin-mediated decay
A flavor-tagged time-dependent angular analysis of the decay
is performed using collision data collected
by the LHCb experiment at % at TeV, the center-of-mass energy of
13 TeV, corresponding to an integrated luminosity of 6 fb^{-1}. The
-violating phase and direct -violation parameter are measured
to be rad and
, respectively, assuming the same values
for all polarization states of the system. In these results, the
first uncertainties are statistical and the second systematic. These parameters
are also determined separately for each polarization state, showing no evidence
for polarization dependence. The results are combined with previous LHCb
measurements using collisions at center-of-mass energies of 7 and 8 TeV,
yielding rad and . This is the most precise study of time-dependent violation
in a penguin-dominated meson decay. The results are consistent with
symmetry and with the Standard Model predictions.Comment: All figures and tables, along with any supplementary material and
additional information, are available at
https://cern.ch/lhcbproject/Publications/p/LHCb-PAPER-2023-001.html (LHCb
public pages
Observation of a resonant structure near the threshold in the decay
An amplitude analysis of the decay is carried out to
study for the first time its intermediate resonant contributions, using
proton-proton collision data collected with the LHCb detector at centre-of-mass
energies of 7, 8 and 13 TeV. A near-threshold peaking structure, referred to as
, is observed in the invariant-mass spectrum with
significance greater than 12 standard deviations. The mass, width and the
quantum numbers of the structure are measured to be MeV,
MeV and , respectively, where the first
uncertainties are statistical and the second systematic. The properties of the
new structure are consistent with recent theoretical predictions for a state
composed of quarks. Evidence for an additional structure is
found around 4140 MeV in the invariant mass, which might be
caused either by a new resonance with the assignment or by a coupled-channel effect.Comment: All figures and tables, along with any supplementary material and
additional information, are available at
https://cern.ch/lhcbproject/Publications/p/LHCb-PAPER-2022-018.html (LHCb
public pages
Measurement of the differential branching fraction
The branching fraction of the rare decay is measured for the first time, in the squared dimuon mass
intervals, , excluding the and regions. The data
sample analyzed was collected by the LHCb experiment at center-of-mass energies
of 7, 8, and 13 TeV, corresponding to a total integrated luminosity of $9\
\mathrm{fb}^{-1}q^{2}q^{2} >15.0\
\mathrm{GeV}^2/c^4$, where theoretical predictions have the smallest model
dependence, agrees with the predictions.Comment: All figures and tables, along with any supplementary material and
additional information, are available at
https://cern.ch/lhcbproject/Publications/p/LHCb-PAPER-2022-050.html (LHCb
public pages
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