2,335 research outputs found

    Electrostatics of Colloidal Particles Confined in Nanochannels: Role of Double-Layer Interactions and Ion-Ion Correlations

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    We perform computational investigations of electrolyte-mediated interactions of charged colloidal particles confined within nanochannels. We investigate the role of discrete ion effects, valence, and electrolyte strength on colloid-wall interactions. We find for some of the multivalent charge regimes that the like-charged colloids and walls can have attractive interactions. We study in detail these interactions and the free energy profile for the colloid-wall separation. We find there are energy barriers and energy minima giving preferred colloid locations in the channel near the center and at a distance near to but separated from the channel walls. We characterize contributions from surface overcharging, condensed layers, and overlap of ion double-layers. We perform our investigations using Coarse-Grained Brownian Dynamics simulations (BD), classical Density Functional Theory (cDFT), and mean-field Poisson-Boltzmann Theory (PB). We discuss the implications of our results for phenomena in nanoscale devices.Comment: 23 figure

    Semantic representation of monogenean haptoral Bar image annotation

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    Background Digitised monogenean images are usually stored in file system directories in an unstructured manner. In this paper we propose a semantic representation of these images in the form of a Monogenean Haptoral Bar Image (MHBI) ontology, which are annotated with taxonomic classification, diagnostic hard part and image properties. The data we used are basically of the monogenean species found in fish, thus we built a simple Fish ontology to demonstrate how the host (fish) ontology can be linked to the MHBI ontology. This will enable linking of information from the monogenean ontology to the host species found in the fish ontology without changing the underlying schema for either of the ontologies. Results In this paper, we utilized the Taxonomic Data Working Group Life Sciences Identifier (TDWG LSID) vocabulary to represent our data and defined a new vocabulary which is specific for annotating monogenean haptoral bar images to develop the MHBI ontology and a merged MHBI-Fish ontologies. These ontologies are successfully evaluated using five criteria which are clarity, coherence, extendibility, ontology commitment and encoding bias Conclusions In this paper, we show that unstructured data can be represented in a structured form using semantics. In the process, we have come up with a new vocabulary for annotating the monogenean images with textual information. The proposed monogenean image ontology will form the basis of a monogenean knowledge base to assist researchers in retrieving information for their analysis

    The effect of stress fracture occurring within the first 12 months of training on subsequent race performance in Thoroughbreds in Hong Kong

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    BACKGROUND Racehorses are at an increased risk of stress fracture within the first 12 months of racing and when resuming training after a break. Research in these high-risk periods and on the effect of performance post-recovery is limited. OBJECTIVES To describe the occurrence of stress fractures, diagnosed by nuclear scintigraphy (NS), in racehorses' first 12 months training in Hong Kong, and their impact on racing performance and career length. STUDY DESIGN Retrospective 1:2 matched case-control study. METHODS Clinical records of horses with NS-diagnosed stress fractures within 365 days of import between 2006 and 2018 were collated. Cases and controls were matched on import date. Univariable conditional logistic regression compared signalment, pre-fracture training and post-recovery racing performance between cases and matched controls. Shared Frailty Cox regression analysed time from import to fracture and total career length. RESULTS Eighty-seven horses sustained a NS-diagnosed fracture within their first year in Hong Kong (incidence risk 1.7% (95% confidence interval (CI) 1.4-2.1%; N=5,180)). The humerus (42.0%; 95% CI 31.8-52.6%; n=39) and tibia (28.0%; 95% CI 19.1-38.2%; n=26) were most common stress fracture sites. Cases missed a median of 63 days (Interquartile range (IQR) 49-82) of training because of fracture. Within the 12 months following diagnosis, case horses had a median of four (IQR 2-4, p<0.0001) fewer race starts and were down HK206,188(IQRHK206,188 (IQR HK0-436,800, p=0.007) in race earnings compared to controls. Career length did not significantly differ between cases and controls (median 2 years and 3 months; IQR 15.3-39.1 months; p=0.2). MAIN LIMITATIONS Only stress fractures diagnosed by NS were included, hence, the study is not representative of all stress fractures occurring in racehorses in Hong Kong. CONCLUSIONS Racehorses sustaining a stress fracture within one year of entering Hong Kong lost significant time in training, earnings and race starts. However, overall career length was unaffected

    Two-center experience of cannabidiol use in adults with Dravet syndrome

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    We describe real-world experience with cannabidiol (CBD) in adults with Dravet Syndrome (DS) via GW Pharma early access programme at two UK neurology centres. Adults with genetically-confirmed DS had CBD added to existing therapy, titrated up to 20 mg/kg, as tolerated. The primary outcome measure was percentage reduction in convulsive seizures. Secondary outcome measures included changes in myoclonic seizures, and in cognition and quality of life as assessed by the Caregiver Global Impression of Change (CGIC), and incidence of adverse events (AEs). 18 adults (7 female; median age 27.5 years; range 20–51) were included. Median follow-up was 176 days. In one, another antiseizure drug, clobazam, was introduced during the programme. 3/17 (17.6%) had >30% reduction in convulsive seizures (range: 87.5–100%). AEs occurred in all, the most common being transaminitis (52.9%). Behavioural AEs led to discontinuation in 3/18 (16.7%), including a seizure-free responder. In 7/18, CBD was stopped due to lack of effect. 8/18 continue on treatment. Improvements in CGIC were reported in 41.2% and 47.1% by physicians and families, respectively. 17.6% achieved sufficient reduction in convulsive seizure frequency to qualify for NHS funding. AEs led to withdrawal in only 16.7%. Close monitoring and dose adjustments of other antiseizure drugs were necessary

    Combustion waves in a model with chain branching reaction and their stability

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    In this paper the travelling wave solutions in the adiabatic model with two-step chain branching reaction mechanism are investigated both numerically and analytically in the limit of equal diffusivity of reactant, radicals and heat. The properties of these solutions and their stability are investigated in detail. The behaviour of combustion waves are demonstrated to have similarities with the properties of nonadiabatic one-step combustion waves in that there is a residual amount of fuel left behind the travelling waves and the solutions can exhibit extinction. The difference between the nonadiabatic one-step and adiabatic two-step models is found in the behaviour of the combustion waves near the extinction condition. It is shown that the flame velocity drops down to zero and a standing combustion wave is formed as the extinction condition is reached. Prospects of further work are also discussed.Comment: pages 32, figures 2

    Reliability and Reproducibility of Landmark Identification in Unilateral Cleft Lip and Palate Patients: Digital Lateral Vis-A-Vis CBCT-Derived 3D Cephalograms

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    Background: The aim of the retrospective observational study was to compare the precision of landmark identification and its reproducibility using cone beam computed tomography-derived 3D cephalograms and digital lateral cephalograms in unilateral cleft lip and palate patients. Methods: Cephalograms of thirty-one (31) North Indian children (18 boys and 13 girls) with a unilateral cleft lip and palate, who were recommended for orthodontic treatment, were selected. After a thorough analysis of peer-reviewed articles, 20 difficult-to-trace landmarks were selected, and their reliability and reproducibility were studied. These were subjected to landmark identification to evaluate interobserver variability; the coordinates for each point were traced separately by three different orthodontists (OBA, OBB, OBC). Statistical analysis was performed using descriptive and inferential statistics with paired t-tests to compare the differences measured by the two methods. Real-scale data are presented in mean ± SD. A p-value less than 0.05 was considered as significant at a 95% confidence level. Results: When comparing, the plotting of points posterior nasal spine (PNS) (p &lt; 0.05), anterior nasal spine (ANS) (p &lt; 0.01), upper 1 root tip (p &lt; 0.05), lower 1 root tip (p &lt; 0.05), malare (p &lt; 0.05), pyriforme (p &lt; 0.05), porion (p &lt; 0.01), and basion (p &lt; 0.05) was statistically significant. Conclusion: In patients with a cleft lip and palate, the interobserver identification of cephalometric landmarks was significantly more precise and reproducible with cone beam computed tomography -derived cephalograms vis-a-vis digital lateral cephalograms

    Gas phase production of NHD2 in L134N

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    We show analytically that large abundances of NH2D and NHD2 can be produced by gas phase chemistry in the interiors of cold dense clouds. The calculated fractionation ratios are in good agreement with the values that have been previously determined in L134N and suggest that triply-deuterated ammonia could be detectable in dark clouds. Grain surface reactions may lead to similar NH2D and NHD2 enhancements but, we argue, are unlikely to contribute to the deuteration observed in L134N.Comment: 6 pages, 2 figures, uses psfig.sty and emulateapj.sty, to appear in Astrophysical Journal, vol 55
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