457 research outputs found
Scalability study of solid xenon
We report a demonstration of the scalability of optically transparent xenon
in the solid phase for use as a particle detector above a kilogram scale. We
employed a cryostat cooled by liquid nitrogen combined with a xenon
purification and chiller system. A modified {\it Bridgeman's technique}
reproduces a large scale optically transparent solid xenon.Comment: arXiv admin note: substantial text overlap with arXiv:1410.649
Recommended from our members
Demagnetization study of pulse-field magnetized bulk superconductors
GdBa2Cu3O7-δ bulk superconductors are a route to higher magnetic fields in rotating machines. Here we examine the resistance of pulse-field magnetized bulks to the demagnetization fields they may experience in such a system. The bulks were magnetized at 77 K, after which several thousand cycles of AC field were applied. Subsequently, the decay of the trapped field was characterized. We found the decay per cycle decreases with frequency and is, normalized to the initial trapped field, largest at the edge of the bulk. At 77 K the reduction in trapped field proved significant (25% in the center for 150 mT (peak) AC field at 6 Hz), however reducing below 1% when lowering the temperature to 60 K. We explain this observation as being due to increased flux pinning strength at low temperatures. When applying an AC field we found a temperature rise that increased with applied field amplitude and frequency. However, when applying an AC field of amplitude 45 mT with a frequency of 48 Hz we found an increase of the bulk temperature of only 100 mK. Therefore, we conclude the temperature rise within the analyzed AC field frequency and amplitude range does not contribute significantly to the decay of trapped field
Genotoxic agents promote the nuclear accumulation of annexin A2: role of annexin A2 in mitigating DNA damage
Annexin A2 is an abundant cellular protein that is mainly localized in the cytoplasm and plasma membrane, however a small population has been found in the nucleus, suggesting a nuclear function for the protein. Annexin A2 possesses a nuclear export sequence (NES) and inhibition of the NES is sufficient to cause nuclear accumulation. Here we show that annexin A2 accumulates in the nucleus in response to genotoxic agents including gamma-radiation, UV radiation, etoposide and chromium VI and that this event is mediated by the nuclear export sequence of annexin A2. Nuclear accumulation of annexin A2 is blocked by the antioxidant agent N-acetyl cysteine (NAC) and stimulated by hydrogen peroxide (H2O2), suggesting that this is a reactive oxygen species dependent event. In response to genotoxic agents, cells depleted of annexin A2 show enhanced phospho-histone H2AX and p53 levels, increased numbers of p53-binding protein 1 nuclear foci and increased levels of nuclear 8-oxo-2'-deoxyguanine, suggesting that annexin A2 plays a role in protecting DNA from damage. This is the first report showing the nuclear translocation of annexin A2 in response to genotoxic agents and its role in mitigating DNA damage.Natural Sciences and Engineering Research Council of Canada (NSERC); European Union [PCOFUND-GA-2009-246542]; Foundation for Science and Technology of Portugal; Beatrice Hunter Cancer Research Institute; Terry Fox Foundationinfo:eu-repo/semantics/publishedVersio
Comparative analysis and optimization of technical and weight parameters of turbo-electric propulsion systems
According to Flightpath 2050, the aviation industry is aiming to substantially reduce emissions over the coming decades. One possible solution to meet these ambitious goals is by moving to hybrid-electric drivetrain architectures which require the electric components to be extremely lightweight and efficient at the same time. It has been claimed in several publications that cryogenic and in particular superconducting components can help to fulfill such requirements that potentially cannot be achieved with non-cryogenic components. The purpose of this work was to make a fair comparison between a cryogenic turbo-electric propulsion system (CEPS) and a non-cryogenic turbo-electric propulsion system (TEPS) on a quantitative level. The results on the CEPS were presented in detail in a previous publication. The focus of this publication is to present the study on the TEPS, which in conclusion allows a direct comparison. For both systems the same top-level aircraft requirements were used that were derived within the project TELOS based on an exemplary mission profile and the physical measures of a 220-passenger aircraft. Our study concludes that a CEPS could be 10% to 40% lighter than a TEPS. Furthermore, a CEPS could have a total efficiency gain of up to 18% compared to a similar TEPS
No evidence of a common DNA variant profile specific to world class endurance athletes
There are strong genetic components to cardiorespiratory fitness and its response to exercise training. It would be useful to understand the differences in the genomic profile of highly trained endurance athletes of world class caliber and sedentary controls. An international consortium (GAMES) was established in order to compare elite endurance athletes and ethnicity-matched controls in a case-control study design. Genome-wide association studies were undertaken on two cohorts of elite endurance athletes and controls (GENATHLETE and Japanese endurance runners), from which a panel of 45 promising markers was identified. These markers were tested for replication in seven additional cohorts of endurance athletes and controls: from Australia, Ethiopia, Japan, Kenya, Poland, Russia and Spain. The study is based on a total of 1520 endurance athletes (835 who took part in endurance events in World Championships and/or Olympic Games) and 2760 controls. We hypothesized that world-class athletes are likely to be characterized by an even higher concentration of endurance performance alleles and we performed separate analyses on this subsample. The meta-analysis of all available studies revealed one statistically significant marker (rs558129 at GALNTL6 locus, p = 0.0002), even after correcting for multiple testing. As shown by the low heterogeneity index (I2 = 0), all eight cohorts showed the same direction of association with rs558129, even though p-values varied across the individual studies. In summary, this study did not identify a panel of genomic variants common to these elite endurance athlete groups. Since GAMES was underpowered to identify alleles with small effect sizes, some of the suggestive leads identified should be explored in expanded comparisons of world-class endurance athletes and sedentary controls and in tightly controlled exercise training studies. Such studies have the potential to illuminate the biology not only of world class endurance performance but also of compromised cardiac functions and cardiometabolic diseases
Hematological and biochemical indicators of lambs’ blood after the use of chemotherapeutic agents for spontaneous eimeriosis
Eimeria infection is one of the protozoal diseases of animals caused by various species of Eimeria and causes reduced productivity and raised mortality in ruminants, especially in young ones. To study the effect of anti-emeriosis drugs on the morphological and biochemical parameters of lambs’ blood infected with Eimeria, 3 groups of Romanov breed animals, two months old, affected by the Eimeria pathogen were formed. The first group of animals was treated with a drug containing the active ingredient decoquinate; the second group of animals with a drug containing the active ingredient toltrazuril; the third group of lambs were given a combined drug containing 80 mg of norsulfazole, 70 mg of sulgin, 30 mg of trimethoprim, 45 mg of oxytetracycline hydrochloride and 25 mg of tylosin tartrate per 1 g); the fourth group of lambs was the control group, the animals were free from the Eimeria pathogen and were kept separately. The blood of the animals was analysed on days 7 and 14 of treatment. In the blood of the experimental lambs, an increase in the number of red blood cells, neutrophils, lymphocytes, and monocytes was noted. There was also a decrease in the total number of leukocytes, eosinophils, young and segmented neutrophils. According to the results of the treatment, there was an increase in the content of total, albumin, hemoglobin and glucose, as well as the activity of gamma-glutamate transferase. At the same time, there was a decrease in the content of globulins and the activity of aspartate aminotransferase and alanine aminotransferase compared to the biochemical parameters of healthy lamb blood serum of the control group. According to treatment results, the restoration of sick lambs’ blood parameters to those of healthy animals was noted; however, the most stable effect was using the combined drug
No Evidence of a Common DNA Variant Profile Specific to World Class Endurance Athletes
There are strong genetic components to cardiorespiratory fitness and its
response to exercise training. It would be useful to understand the
differences in the genomic profile of highly trained endurance athletes of
world class caliber and sedentary controls. An international consortium
(GAMES) was established in order to compare elite endurance athletes and
ethnicity-matched controls in a case-control study design. Genome-wide
association studies were undertaken on two cohorts of elite endurance athletes
and controls (GENATHLETE and Japanese endurance runners), from which a panel
of 45 promising markers was identified. These markers were tested for
replication in seven additional cohorts of endurance athletes and controls:
from Australia, Ethiopia, Japan, Kenya, Poland, Russia and Spain. The study is
based on a total of 1520 endurance athletes (835 who took part in endurance
events in World Championships and/or Olympic Games) and 2760 controls. We
hypothesized that world-class athletes are likely to be characterized by an
even higher concentration of endurance performance alleles and we performed
separate analyses on this subsample. The meta-analysis of all available
studies revealed one statistically significant marker (rs558129 at GALNTL6
locus, p = 0.0002), even after correcting for multiple testing. As shown by
the low heterogeneity index (I2 = 0), all eight cohorts showed the same
direction of association with rs558129, even though p-values varied across the
individual studies. In summary, this study did not identify a panel of genomic
variants common to these elite endurance athlete groups. Since GAMES was
underpowered to identify alleles with small effect sizes, some of the
suggestive leads identified should be explored in expanded comparisons of
world-class endurance athletes and sedentary controls and in tightly
controlled exercise training studies. Such studies have the potential to
illuminate the biology not only of world class endurance performance but also
of compromised cardiac functions and cardiometabolic diseases
Recommended from our members
Reliable 4.8 T trapped magnetic fields in Gd-Ba-Cu-O bulk superconductors using pulsed field magnetization
Abstract
A robust and reliable in-situ magnetization method is essential for exploiting the outstanding magnetic flux trapping ability of bulk superconductors in practical applications. We report a 4.8 T peak trapped magnetic field, B
T, achieved at 30 K in a 36 mm diameter GdBa2Cu3O7-δ
–Ag bulk superconductor using pulsed field magnetization (PFM). To realize this, we have developed a reliable two-step multi-pulse PFM process based on understanding and exploiting the avalanche-like flux jump phenomenon observed in these materials. The magnitude of the applied pulsed magnetic field (B
a) necessary to trap 4.8 T was merely 5.29 T, corresponding to a remarkable magnetization efficiency (B
T/B
a) of 90%.This study was supported by the Engineering and Physical Sciences Research Council (No. EP/P00962X/1), the Strategic Priority Research Program of the Chinese Academy of Sciences (No. XDB25000000), the National Key R&D Program (2016YFF0101701) and the project (6140923050202). M D Ainslie would like to acknowledge financial support from an Engineering and Physical Sciences Research Council (EPSRC) Early Career Fellowship, EP/P020313/
Replication of KCNJ11 (p.E23K) and ABCC8 (p.S1369A) association in Russian diabetes mellitus 2 type cohort and meta-analysis
© 2015 Sokolova et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. The genes ABCC8 and KCNJ11 have received intense focus in type 2 diabetes mellitus (T2DM) research over the past two decades. It has been hypothesized that the p.E23K (KCNJ11) mutation in the 11p15.1 region may play an important role in the development of T2DM. In 2009, Hamming et al. found that the p.1369A (ABCC8) variant may be a causal factor in the disease; therefore, in this study we performed a meta-analysis to evaluate the association between these single nucleotide polymorphisms (SNPs), including our original data on the Siberian population (1384 T2DM and 414 controls). We found rs5219 and rs757110 were not associated with T2DM in this population, and that there was linkage disequilibrium in Siberians (D'=0.766, r2= 0.5633). In addition, the haplotype rs757110[T]- rs5219[C] (p.23K/p.S1369) was associated with T2DM (OR = 1.52, 95% CI: 1.04-2.24). We included 44 original studies published by June 2014 in a meta-analysis of the p.E23K association with T2DM. The total OR was 1.14 (95% CI: 1.11-1.17) for p.E23K for a total sample size of 137,298. For p.S1369A, a meta-analysis was conducted on a total of 10 studies with a total sample size of 14,136 and pooled OR of 1.14 [95% CI (1.08-1.19); p = 2 × 10-6]. Our calculations identified causal genetic variation within the ABCC8/KCNJ11region for T2DM with an OR of approximately 1.15 in Caucasians and Asians. Moreover, the OR value was not dependent on the frequency of p.E23K or p.S1369A in the populations
- …
