2,379 research outputs found
Vertigo returning to the sitting position after the Semont manoeuvre. Is it a prognostic symptom?
Assessment of the Kinematic Adaptations in Parkinson’s Disease Using the Gait Profile Score: Influences of Trunk Posture, a Pilot Study
Introduction: Postural abnormalities are common in patients with Parkinson’s disease (PD) and lead to gait abnormalities. Relationships between changes in the trunk posture of PD patients and gait profile score (GPS) and gait spatiotemporal parameters are poorly investigated. The aim of the current study was to investigate the relationships between trunk posture, GPS, and gait spatiotemporal parameters, in patients with PD. Materials and Methods: Twenty-three people with PD and nineteen age-matched healthy people participated in this study. A 3D gait kinematical analysis was applied to all participants using the Plug-In Gait Full Body™ tool. Trunk and limb kinematics patterns and gait spatio-temporal parameters of patients with PD and the control group were compared. Additionally, correlations between trunk kinematics patterns, gait spatio-temporal parameters, and GPS of the PD group were tested. Results: Cadence, opposite foot off, step time, single support, double support, foot off, gait speed, trunk kinematics, and GPS showed significant differences between the two groups (p ≤ 0.05). Posture of the trunk during gait was not related to the spatio-temporal parameters and gait profile score in the PD group. The trunk flexor pattern influenced GPS domains, mainly of the ankle and the knee. Discussion and Conclusions: Flexed posture of the trunk in patients with PD seems to influence both ankle and knee movement patterns during the gait. The GPS analysis provided direct and simplified kinematic information for the PD group. These results may have implications for understanding the importance of considering the positioning of the trunk during gait
Limits on the neutrino magnetic moment from the MUNU experiment
The MUNU experiment was carried out at the Bugey nuclear power reactor. The
aim was the study of electron antineutrino-electron elastic scattering at low
energy. The recoil electrons were recorded in a gas time projection chamber,
immersed in a tank filled with liquid scintillator serving as veto detector,
suppressing in particular Compton electrons. The measured electron recoil
spectrum is presented. Upper limits on the neutrino magnetic moment were
derived and are discussed.Comment: 9 pages, 7 figures Added reference: p.3, 1st col., TEXONO Added
sentence: p.4, 1st col., electron attachement Modified sentence: p.5, 1st
col., readout sequence Added sentence: p.5, 1st col., fast rise time cu
Understanding ligand binding selectivity in a prototypical GPCR family
Adenosine receptors are involved in many pathological conditions and are thus promising drug targets. However, developing drugs that target this GPCR subfamily is a challenging task. A number of drug candidates fail due to lack of selectivity which results in unwanted side effects. The extensive structural similarity of adenosine receptors complicates the design of selective ligands. The problem of selective targeting is a general concern in GPCRs and in this respect adenosine receptors are a prototypical example. Here we use enhanced sampling simulations to decipher the determinants of selectivity of ligands in A2a and A1 adenosine receptors. Our model shows how small differences in the binding pocket and in the water network around the ligand can be leveraged to achieve selectivity
Complex microwave conductivity of Na-DNA powders
We report the complex microwave conductivity, , of
Na-DNA powders, which was measured from 80 K to 300 K by using a microwave
cavity perturbation technique. We found that the magnitude of near
room temperature was much larger than the contribution of the surrounding water
molecules, and that the decrease of with decreasing temperature was
sufficiently stronger than that of the conduction of counterions. These results
clearly suggest that the electrical conduction of Na-DNA is intrinsically
semiconductive.Comment: 16 pages, 7 figure
Quantum transport through a DNA wire in a dissipative environment
Electronic transport through DNA wires in the presence of a strong
dissipative environment is investigated. We show that new bath-induced
electronic states are formed within the bandgap. These states show up in the
linear conductance spectrum as a temperature dependent background and lead to a
crossover from tunneling to thermal activated behavior with increasing
temperature. Depending on the strength of the electron-bath coupling, the
conductance at the Fermi level can show a weak exponential or even an algebraic
length dependence. Our results suggest a new environmental-induced transport
mechanism. This might be relevant for the understanding of molecular conduction
experiments in liquid solution, like those recently performed on poly(GC)
oligomers in a water buffer (B. Xu et al., Nano Lett 4, 1105 (2004)).Comment: 5 pages, 3 figure
The use of chest ultrasonography in suspected cases of COVID-19 in the emergency department
Aim: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus-specific reverse transcriptase-polymerase chain reaction (RT-PCR) represents the diagnostic gold standard. We explored the value of chest ultrasonography to predict positivity to SARS-CoV-2 on RT-PCR in suspected COVID-19 cases. Patients & methods: Consecutive patients with suspect COVID-19 were included if they had fever and/or history of cough and/or dyspnea. Lung ultrasound score (LUSS) was computed according to published methods. Results: A total of 76 patients were included. A 3-variable model based on aspartate transaminase (AST) > upper limit of normal, LUSS >12 and body temperature >37.5°C yielded an overall accuracy of 91%. Conclusion: A simple LUSS-based model may represent a powerful tool for initial assessment in suspected cases of COVID-19. The gold standard for diagnosis of COVID-19 is RT-PCR. During a pandemic emergency, it may be useful to identify suspect symptomatic patients who may safely be observed without undergoing testing for COVID-19. In this work, a simple model based on the findings of lung ultrasound, AST levels and fever showed an overall accuracy of 91% to predict the results of RT-PCR
Intrinsically active MEK variants are differentially regulated by proteinases and phosphatases
MAPK/ERK kinase (MEK) 1/2 are central signaling proteins that serve as specificity determinants of the MAPK/ERK cascade. More than twenty activating mutations have been reported for MEK1/2, and many of them are known to cause diseases such as cancers, arteriovenous malformation and RASopathies. Changes in their intrinsic activity do not seem to correlate with the severity of the diseases. Here we studied four MEK1/2 mutations using biochemical and molecular dynamic methods. Although the studied mutants elevated the activating phosphorylation of MEK they had no effect on the stimulated ERK1/2 phosphorylation. Studying the regulatory mechanism that may explain this lack of effect, we found that one type of mutation affects MEK stability and two types of mutations demonstrate a reduced sensitivity to PP2A. Together, our results indicate that some MEK mutations exert their function not only by their elevated intrinsic activity, but also by modulation of regulatory elements such as protein stability or dephosphorylation
High sensitivity GEM experiment on double beta decay of 76-Ge
The GEM project is designed for the next generation 2 beta decay experiments
with 76-Ge. One ton of ''naked'' HP Ge detectors (natural at the first GEM-I
phase and enriched in 76-Ge to 86% at the second GEM-II stage) are operating in
super-high purity liquid nitrogen contained in the Cu vacuum cryostat (sphere
with diameter 5 m). The latest is placed in the water shield. Monte Carlo
simulation evidently shows that sensitivity of the experiment (in terms of the
T1/2 limit for neutrinoless 2 beta decay) is 10^27 yr with natural HP Ge
crystals and 10^28 yr with enriched ones. These bounds corresponds to the
restrictions on the neutrino mass less than 0.05 eV and 0.015 eV with natural
and enriched detectors, respectively. Besides, the GEM-I set up could advance
the current best limits on the existence of neutralinos - as dark matter
candidates - by three order of magnitudes, and at the same time would be able
to identify unambiguously the dark matter signal by detection of its seasonal
modulation.Comment: LaTeX, 20 pages, 4 figure
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