201 research outputs found
Critical exponents at the ferromagnetic transition in tetrakis(diethylamino)ethylene-C (TDAE-C)
Critical exponents at the ferromagnetic transition were measured for the
first time in an organic ferromagnetic material tetrakis(dimethylamino)ethylene
fullerene[60] (TDAE-C). From a complete magnetization-temperature-field
data set near we determine the susceptibility and
magnetization critical exponents and respectively, and the field vs. magnetization exponent at of
. Hyperscaling is found to be violated by , suggesting that the onset of ferromagnetism can be
related to percolation of a particular contact configuration of C
molecular orientations.Comment: 5 pages, including 3 figures; to appear in Phys. Rev. Let
Magnetic phases of skyrmion-hosting GaV4S8−ySey (y = 0, 2, 4, 8) probed with muon spectroscopy
We present the results of a muon-spin spectroscopy investigation of GaV4S8−ySey with y = 0, 2, 4, and 8. Zero-field measurements suggest that GaV4Se8 and GaV4S8 have distinct magnetic ground states, with the latter material showing an anomalous temperature dependence of the local magnetic field. It is not possible to evolve the magnetic state continuously between these two systems, with the intermediate y = 2 and 4 materials showing glassy magnetic behavior at low temperature. The skyrmion lattice (SkL) phase is evident in the y = 0 and 8 materials through an enhanced response of the muon-spin relaxation to the emergent dynamics that accompany the SkL. For our polycrystalline samples of GaV4Se8, this enhanced dynamic response is confined to a smaller region of the magnetic field-temperature phase diagram than the previous reports of the SkL in single crystals
3,4-Diaminopyridine Base Effectively Treats the Weakness of Lambert-Eaton Myasthenia
Introduction: 3,4-diaminopyridine has been used to treat Lambert Eaton myasthenia (LEM) for thirty years despite the lack of conclusive evidence of efficacy.
Methods: We conducted a randomized double-blind placebo-controlled withdrawal study in LEM patients who had been on stable regimens of 3,4-diaminopyridine base (3,4-DAP) for ≥ 3 months. The primary efficacy endpoint was >30% deterioration in Triple Timed Up-and-Go (3TUG) times during tapered drug withdrawal. The secondary endpoint was self-assessment of LEM–related weakness (W-SAS).
Results: 32 participants were randomized to continuous 3,4-DAP or placebo. None of the 14 receiving continuous 3,4-DAP had >30% deterioration in 3TUG time vs 72% of the 18 who tapered to placebo (p<0.0001). W-SAS similarly demonstrated an advantage for continuous treatment over placebo (p<0.0001). Need for rescue and adverse events were more common in the placebo group.
Discussion: This trial provides significant evidence of efficacy of 3,4-DAP in the maintenance of strength in LEM
Validation of the triple timed up‐and‐go test in Lambert‐Eaton myasthenia
Introduction
There are no validated, practical, and quantitative measures of disease severity in Lambert‐Eaton myasthenia (LEM).
Methods
Data from the Effectiveness of 3,4‐Diaminopyridine in Lambert‐Eaton Myasthenic Syndrome (DAPPER) trial were analyzed to assess triple timed up‐and‐go (3TUG) reproducibility and relationships between 3TUG times and other measures of LEM severity.
Results
The coverage probability technique showed ≥0.90 probability for an acceptable 3TUG difference of ≤0.2, indicating that it is reproducible in LEM patients. The correlation between 3TUG times and lower extremity function scores was significant in subjects who continued and in those who were withdrawn from 3,4‐diaminopyridine free base. Worsening patient‐reported Weakness Self‐Assessment Scale and Investigator Assessment of Treatment Effect scores corresponded with prolongation of 3TUG times.
Discussion
The 3TUG is reproducible, demonstrates construct validity for assessment of lower extremity function in LEM patients, and correlates with changes in patient and physician assessments. These findings, along with prior reliability studies, indicate 3TUG is a valid measure of disease severity in LEM
Regional variation in the role of humidity on city-level heat-related mortality.
The rising humid heat is regarded as a severe threat to human survivability, but the proper integration of humid heat into heat-health alerts is still being explored. Using state-of-the-art epidemiological and climatological datasets, we examined the association between multiple heat stress indicators (HSIs) and daily human mortality in 739 cities worldwide. Notable differences were observed in the long-term trends and timing of heat events detected by HSIs. Air temperature (Tair) predicts heat-related mortality well in cities with a robust negative Tair-relative humidity correlation (CT-RH). However, in cities with near-zero or weak positive CT-RH, HSIs considering humidity provide enhanced predictive power compared to Tair. Furthermore, the magnitude and timing of heat-related mortality measured by HSIs could differ largely from those associated with Tair in many cities. Our findings provide important insights into specific regions where humans are vulnerable to humid heat and can facilitate the further enhancement of heat-health alert systems
Estimating the Fractal Dimension, K_2-entropy, and the Predictability of the Atmosphere
The series of mean daily temperature of air recorded over a period of 215
years is used for analysing the dimensionality and the predictability of the
atmospheric system. The total number of data points of the series is 78527.
Other 37 versions of the original series are generated, including ``seasonally
adjusted'' data, a smoothed series, series without annual course, etc. Modified
methods of Grassberger and Procaccia are applied. A procedure for selection of
the ``meaningful'' scaling region is proposed. Several scaling regions are
revealed in the ln C(r) versus ln r diagram. The first one in the range of
larger ln r has a gradual slope and the second one in the range of intermediate
ln r has a fast slope. Other two regions are settled in the range of small ln
r. The results lead us to claim that the series arises from the activity of at
least two subsystems. The first subsystem is low-dimensional (d_f=1.6) and it
possesses the potential predictability of several weeks. We suggest that this
subsystem is connected with seasonal variability of weather. The second
subsystem is high-dimensional (d_f>17) and its error-doubling time is about 4-7
days. It is found that the predictability differs in dependence on season. The
predictability time for summer, winter and the entire year (T_2 approx. 4.7
days) is longer than for transition-seasons (T_2 approx. 4.0 days for spring,
T_2 approx. 3.6 days for autumn). The role of random noise and the number of
data points are discussed. It is shown that a 15-year-long daily temperature
series is not sufficient for reliable estimations based on Grassberger and
Procaccia algorithms.Comment: 27 pages (LaTex version 2.09) and 15 figures as .ps files, e-mail:
[email protected]
Genetic screening of Fabry patients with EcoTILLING and HRM technology
<p>Abstract</p> <p>Background</p> <p>Anderson-Fabry disease (FD) is caused by a deficit of the α-galactosidase A enzyme which leads to the accumulation of complex sphingolipids, especially globotriaosylceramide (Gb3), in all the cells of the body, causing the onset of a multi-systemic disease with poor prognosis in adulthood. In this article, we describe two alternative methods for screening the <it>GLA </it>gene which codes for the α-galactosidase A enzyme in subjects with probable FD in order to test analysis strategies which include or rely on initial pre-screening.</p> <p>Findings</p> <p>We analyzed 740 samples using EcoTILLING, comparing two mismatch-specific<ul/>endonucleases, CEL I and ENDO-1, while conducting a parallel screening of the same samples using HRM (High Resolution Melting). Afterwards, all samples were subjected to direct sequencing. Overall, we identified 12 different genetic variations: -10C>T, -12G>A, -30G>A, IVS2-76_80del5, D165H, C172Y, IVS4+16A>G, IVS4 +68 A>G, c.718_719delAA, D313Y, IVS6-22C>T, G395A. This was consistent with the high genetic heterogeneity found in FD patients and carriers. All of the mutations were detected by HRM, whereas 17% of the mutations were not found by EcoTILLING. The results obtained by EcoTILLING comparing the CEL I and ENDO-1 endonucleases were perfectly overlapping.</p> <p>Conclusion</p> <p>On the basis of its simplicity, flexibility, repeatability, and sensitivity, we believe that<ul/>HRM analysis of the <it>GLA </it>gene is a reliable presequencing screening tool. This method can be applied to any genomic feature to identify known and unknown genetic alterations, and it is ideal for conducting screening and population studies.</p
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Short term association between ozone and mortality: global two stage time series study in 406 locations in 20 countries
Objective To assess short term mortality risks and excess mortality associated with exposure to ozone in several cities worldwide. Design Two stage time series analysis. Setting 406 cities in 20 countries, with overlapping periods between 1985 and 2015, collected from the database of Multi-City Multi-Country Collaborative Research Network. Population Deaths for all causes or for external causes only registered in each city within the study period. Main outcome measures Daily total mortality (all or non-external causes only). Results A total of 45 165 171 deaths were analysed in the 406 cities. On average, a 10 μg/m 3 increase in ozone during the current and previous day was associated with an overall relative risk of mortality of 1.0018 (95% confidence interval 1.0012 to 1.0024). Some heterogeneity was found across countries, with estimates ranging from greater than 1.0020 in the United Kingdom, South Africa, Estonia, and Canada to less than 1.0008 in Mexico and Spain. Short term excess mortality in association with exposure to ozone higher than maximum background levels (70 μg/m 3) was 0.26% (95% confidence interval 0.24% to 0.28%), corresponding to 8203 annual excess deaths (95% confidence interval 3525 to 12 840) across the 406 cities studied. The excess remained at 0.20% (0.18% to 0.22%) when restricting to days above the WHO guideline (100 μg/m 3), corresponding to 6262 annual excess deaths (1413 to 11 065). Above more lenient thresholds for air quality standards in Europe, America, and China, excess mortality was 0.14%, 0.09%, and 0.05%, respectively. Conclusions Results suggest that ozone related mortality could be potentially reduced under stricter air quality standards. These findings have relevance for the implementation of efficient clean air interventions and mitigation strategies designed within national and international climate policies. © Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to
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