1,114 research outputs found
An investigation into the use of < 38 µm fraction as a proxy for < 10 µm road dust particles
It is well documented that a large portion of urban particulate matters is derived from road dust. Isolating particles of RD which are small enough to be inhaled, however, is a difficult process. In this study, it is shown for the first time that the < 38 µm fraction of road dust particles can be used as a proxy for road dust particles < 10 µm in bioaccessibility studies. This study probed similarities between the < 10 and < 38µm fractions of urban road dust to show that the larger of the two can be used for analysis for which larger sample masses are required, as is the case with in vitro analysis. Road dust, initially segregated to size < 38 µm using sieves, was again size segregated to < 10 µm using water deposition. Both the original < 38 µm and the separated < 10 µm fractions were then subject to single particle analysis by SEM–EDX and bulk analysis by ICP-OES for its elemental composition. Dissolution tests in artificial lysosomal fluid, representative of lung fluid, were carried out on both samples to determine % bioaccessibility of selected potentially harmful elements and thus probe similarities/differences in in vitro behaviour between the two fractions. The separation technique achieved 94.3% of particles < 10 µm in terms of number of particles (the original sample contained 90.4% as determined by SEM–EDX). Acid-soluble metal concentration results indicated differences between the samples. However, when manipulated to negate the input of Si, SEM–EDX data showed general similarities in metal concentrations. Dissolution testing results indicated similar behaviour between the two samples in a simulated biological fluid
Pyrimidine nucleosides syntheses by late-stage base heterocyclization reactions
An efficient two-step procedure for the syntheses of pyrimidine nucleosides is presented. A series of glycosyl 5-(aminomethylene)-1,3-dioxane-4,6-dione derivatives were prepared from β-anomeric isonitriles by reaction with Meldrum’s acid or by allowing aminomethylene Meldrum’s acid to react with an 1-aldofuranosyl halide or acetate. The resultant 5-(aminomethylene)-1,3-dioxane-4,6-dione derivatives underwent reaction with benzyl- or 2,4-dimethoxybenzyl isocyanate via transacylation to provide uridine-5-carboxylic acid derivatives and related nucleosides. These nucleoside carboxylic acids were converted into other C-5 derivatives by bromo-decarboxylation with N-bromosuccinimide
Prescription of oral anticoagulants and antiplatelets for stroke prophylaxis in atrial fibrillation: nationwide time series ecological analysis
Aims:
To investigate trends in the prescription of oral anticoagulants (OACs) and antiplatelet agents for atrial fibrillation (AF).
Methods and results:
Prescription data for 450 518 patients with AF from 3352 General Practices in England, was obtained from the GRASP-AF registry, 2009–2018. Annualized temporal trends for OAC and antiplatelet prescription were reported according to eligibility based on stroke risk (CHADS2 or CHA2DS2-VASc scores ≥1 or >2, respectively). From 2009 to 2018, the prevalence of AF increased from 1.6% [95% confidence interval (CI) 1.5–1.7%] to 2.4% (2.3–2.5%), and for those with AF the proportion prescribed OAC increased from 47.6% to 75.0% (P-trend < 0.001; relative risk 1.57, 95% CI 1.55–1.60) and for antiplatelet decreased from 37.4% to 9.2% (P-trend < 0.001). In early-years (2009–2013), eligible patients aged ≥80 years were less likely to be prescribed OAC than patients aged <80 years [odds ratio (OR) 0.55, 95% CI 0.51–0.59 for CHADS2≥1 in 2009] (all P-trends < 0.001). This ‘OAC prescription gap’ reduced over the study period (OR 0.93, 0.90–0.96 in 2018). Whilst the prescription of direct oral anticoagulant (DOAC) as a proportion of all OAC increased from 0.1% (95% CI 0.0–0.2%) in 2011 to 58.8% (58.4–59.2%) in 2018, it was inversely associated with patient age (P-trend < 0.001) and their risk of stroke.
Conclusion:
Between 2009 and 2018, in England, the use of OAC for stroke prophylaxis in AF increased, with DOAC accounting for over half of OAC uptake in 2018. Despite a reduction in the OAC-prescription gap, a new paradox exists relating to DOAC prescription for the elderly and those at higher risk of stroke
Quantum teleportation between light and matter
Quantum teleportation is an important ingredient in distributed quantum
networks, and can also serve as an elementary operation in quantum computers.
Teleportation was first demonstrated as a transfer of a quantum state of light
onto another light beam; later developments used optical relays and
demonstrated entanglement swapping for continuous variables. The teleportation
of a quantum state between two single material particles (trapped ions) has now
also been achieved. Here we demonstrate teleportation between objects of a
different nature - light and matter, which respectively represent 'flying' and
'stationary' media. A quantum state encoded in a light pulse is teleported onto
a macroscopic object (an atomic ensemble containing 10^12 caesium atoms).
Deterministic teleportation is achieved for sets of coherent states with mean
photon number (n) up to a few hundred. The fidelities are 0.58+-0.02 for n=20
and 0.60+-0.02 for n=5 - higher than any classical state transfer can possibly
achieve. Besides being of fundamental interest, teleportation using a
macroscopic atomic ensemble is relevant for the practical implementation of a
quantum repeater. An important factor for the implementation of quantum
networks is the teleportation distance between transmitter and receiver; this
is 0.5 metres in the present experiment. As our experiment uses propagating
light to achieve the entanglement of light and atoms required for
teleportation, the present approach should be scalable to longer distances.Comment: 23 pages, 8 figures, incl. supplementary informatio
Cognitive appraisal of environmental stimuli induces emotion-like states in fish
The occurrence of emotions in non-human animals has been the focus of debate over the years. Recently, an interest in expanding this debate to non-tetrapod vertebrates and to invertebrates has emerged. Within vertebrates, the study of emotion in teleosts is particularly interesting since they represent a divergent evolutionary radiation from that of tetrapods, and thus they provide an insight into the evolution of the biological mechanisms of emotion. We report that Sea Bream exposed to stimuli that vary according to valence (positive, negative) and salience (predictable, unpredictable) exhibit different behavioural, physiological and neuromolecular states. Since according to the dimensional theory of emotion valence and salience define a two-dimensional affective space, our data can be interpreted as evidence for the occurrence of distinctive affective states in fish corresponding to each the four quadrants of the core affective space. Moreover, the fact that the same stimuli presented in a predictable vs. unpredictable way elicited different behavioural, physiological and neuromolecular states, suggests that stimulus appraisal by the individual, rather than an intrinsic characteristic of the stimulus, has triggered the observed responses. Therefore, our data supports the occurrence of emotion-like states in fish that are regulated by the individual's perception of environmental stimuli.European Commission [265957 Copewell]; Fundacao para a Ciencia e Tecnologia [SFRH/BD/80029/2011, SFRH/BPD/72952/2010]info:eu-repo/semantics/publishedVersio
Memory for expectation-violating concepts:The effects of agents and cultural familiarity
Previous research has shown that ideas which violate our expectations, such as schema-inconsistent concepts, enjoy privileged status in terms of memorability. In our study, memory for concepts that violate cultural (cultural schema-level) expectations (e.g., "illiterate teacher", "wooden bottle", or "thorny grass") versus domain-level (ontological) expectations (e.g., "speaking cat", "jumping maple", or "melting teacher") was examined. Concepts that violate cultural expectations, or counter-schematic, were remembered to a greater extent compared with concepts that violate ontological expectations and with intuitive concepts (e.g., "galloping pony", "drying orchid", or "convertible car"), in both immediate recall, and delayed recognition tests. Importantly, concepts related to agents showed a memory advantage over concepts not pertaining to agents, but this was true only for expectation-violating concepts. Our results imply that intuitive, everyday concepts are equally attractive and memorable regardless of the presence or absence of agents. However, concepts that violate our expectations (cultural-schema or domain-level) are more memorable when pertaining to agents (humans and animals) than to non-agents (plants or objects/artifacts). We conclude that due to their evolutionary salience, cultural ideas which combine expectancy violations and the involvement of an agent are especially memorable and thus have an enhanced probability of being successfully propagated. © 2014 Porubanova et al
Memory-experience gap in early adolescents' happiness reports
Studies among adult populations show that estimates of how happy one has felt in the past tend
to be more positive than average happiness as assessed using time sampling techniques. This
‘memory-experience gap’ is attributed to cognitive biases, among which fading affect bias. In
this paper we report a study among 352 pupils of a secondary school in the Netherlands. These
youngsters reported subsequently: 1) how happy they had felt yesterday, 2) how happy they had
felt during the last month, 3) what they had done the previous day and 4) how the
Baseline observations from the POSSIBLE EU® study: characteristics of postmenopausal women receiving bone loss medications
Summary: Prospective Observational Scientific Study Investigating Bone Loss Experience in Europe (POSSIBLE
EU®) is an ongoing longitudinal cohort study that utilises
physician- and patient-reported measures to describe the
characteristics and management of postmenopausal women
on bone loss therapies. We report the study design and
baseline characteristics of 3,402 women recruited from
general practice across five European countries.
Purpose The POSSIBLE EU® is a study describing the
characteristics and management of postmenopausal women
receiving bone loss medications.
Methods: Between 2005 and 2008, general practitioners
enrolled postmenopausal women initiating, switching or
continuing treatment with bone loss treatment in France,
Germany, Italy, Spain and the UK. Patients and physicians
completed questionnaires at study entry and at 3-month
intervals, for 1 year.
Results: Of 3,402 women enrolled (mean age 68.2 years
[SD] 9.83), 96% were diagnosed with low bone mass; 55%
of these using dual energy X-ray absorptiometry. Most
women (92%) had comorbidities. Mean minimum T score
(hip or spine) at diagnosis was −2.7 (SD 0.89; median −2.7
[interquartile range, −3.2, −2.2]) indicating low bone
mineral density. Almost 40% of the women had prior
fractures in adulthood, mostly non-vertebral, non-hip in
nature, 30% of whom had at least two fractures and more
than half experienced moderate/severe pain or fatigue.
Bisphosphonates were the most common type of bone loss
treatment prescribed in the 12 months preceding the study.
Conclusions POSSIBLE EU® characterises postmenopausal
women with low bone mass, exhibiting a high rate of
prevalent fracture, substantial bone fragility and overall
comorbidity burden. Clinical strategies for managing
osteoporosis in this population varied across the five
participating European countries, reflecting their different
guidelines, regulations and standards of care
Association analysis of PRNP gene region with chronic wasting disease in Rocky Mountain elk
<p>Abstract</p> <p>Background</p> <p>Chronic wasting disease (CWD) is a transmissible spongiform encephalopathy (TSE) of cervids including white-tailed (<it>Odocoileus virginianus</it>) and mule deer (<it>Odocoileus hemionus</it>), Rocky Mountain elk (<it>Cervus elaphus nelsoni</it>), and moose (<it>Alces alces</it>). A leucine variant at position 132 (132L) in prion protein of Rocky Mountain elk confers a long incubation time with CWD, but not complete resistance. However, variants in regulatory regions outside the open reading frame of <it>PRNP </it>have been associated with varying degrees of susceptibility to prion disease in other species, and some variants have been observed in similar regions of Rocky Mountain elk <it>PRNP</it>. Thus, additional genetic variants might provide increased protection, either alone or in combination with 132L.</p> <p>Findings</p> <p>This study provided genomic sequence of all exons for <it>PRNP </it>of Rocky Mountain elk. Many functional sites in and around the <it>PRNP </it>gene region were sequenced, and this report approximately doubled (to 75) the number of known variants in this region. A haplotype-tagging approach was used to reduce the number of genetic variants required to survey this variation in the <it>PRNP </it>gene region of 559 Rocky Mountain elk. Eight haplotypes were observed with frequencies over 1.0%, and one haplotype was present at 71.2% frequency, reflecting limited genetic diversity in the <it>PRNP </it>gene region.</p> <p>Conclusions</p> <p>The presence of 132L cut odds of CWD by more than half (Odds Ratio = 0.43; P = 0.0031), which was similar to a previous report. However after accounting for 132L, no association with CWD was found for any additional variants in the <it>PRNP </it>region (P > 0.05).</p
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