Abstract
Introduction
Many endoscopists do not use split-dose bowel preparation (SDBP) for morning colonoscopies. Despite SDBP being recommended practice, they believe patients will not agree to ...take early morning bowel preparation (BP). We assessed patients’ opinions about waking early for BP.
Methods
A self-administered survey was distributed between 08/2015 and 06/2016 to patients in Winnipeg, Canada when they attended an outpatient colonoscopy. Logistic regression was performed to determine predictors of reluctance to use early morning BP.
Results
Of the 1336 respondents (52 % female, median age 57 years), 33 % had used SDBP for their current colonoscopy. Of the 1336, 49 % were willing, 24 % neutral, and 27 % reluctant to do early morning BP. Predictors of reluctant versus willing were number of prior colonoscopies (OR 1.20; 95 %CI: 1.07 – 1.35), female gender (OR 1.65; 95 %CI: 1.19 – 2.29), unclear BP information (OR 1.86; 95 %CI: 1.21 – 2.85), high BP anxiety (OR 2.02; 95 %CI: 1.35 – 3.02), purpose of current colonoscopy being bowel symptoms (OR 1.40; 95 %CI: 1.00 – 1.97), use of 4 L of polyethylene glycol laxative (OR 1.45; 95 %CI: 1.02 – 2.06), not having SDBP (OR 1.96; 95 %CI: 1.31 – 2.93), and not having finished the laxative for the current colonoscopy (OR 1.66; 95 %CI: 1.01 – 2.73). Most of the same predictors were identified when reluctance was compared to willing or neutral, and in ordinal logistic regression.
Conclusions
Almost three-quarters of patients do not express reluctance to get up early for BP. Among those who are reluctant, improving BP information, allaying BP-related anxiety, and use of low volume BP may increase acceptance of SDBP.
An impregnation model has been developed to evaluate the infiltration phenomena that occur during a novel near net shape preforming method. This process comprises automated deposition of ...thermoplastic resin and unidirectional (UD) carbon fibres to a pre-programmed stacking sequence, thereby forming tailored preforms for subsequent stamp-forming. Infiltration kinetics have been simulated to study the effect of different stacking scenarios, materials, and pre-consolidation routes on the novel preforming process. Isothermal infiltration of a liquid thermoplastic polymer into a compressed UD fibre bed has been examined and the experimental results have been used to validate an infiltration model based on local fluid flow in compressible porous media. This enables simulation of infiltration in alternating matrix film and fibre layers, relating pressure, time, and temperature with the local fibre volume fraction, pressure, and liquid and solid velocities in the stacked material. For a given set of processing conditions, the model fibre volume fraction distribution prediction enables the optimum matrix stacking layer thicknesses to be determined. It was shown that infiltration is inhibited above a limiting pressure which leads to increased fibre bed compaction and hence decreased permeability.
We investigated the healing of epoxy resins with embedded ethyl phenylacetate (EPA) solvent loaded capsules and shape memory alloy (SMA) wires under fatigue loading in tapered double cantilever beam ...(TDCB) mode. Under cyclic loading, the kinetics of solvent diffusion are in competition with the rate of damage propagation. We showed that the active mechanism of self-healing under continuous loading is different from that in quasi-static testing. Crack arrest was observed after some initial crack growth, resulting from the diffusion of EPA solvent into the crack tip, involving local plasticization of the epoxy. Finite element analysis confirmed that the lower modulus and higher elongation at break of the solvated epoxy reduced the stresses at the crack tip. This effect combined with the well-studied microcapsule toughening effect, tremendously increased the toughness of plain epoxy. For epoxy with embedded SMA wires, completely fractured samples, healed using SMA activation, showed similar fatigue resistance as virgin samples. Furthermore, SMA activation during a 10 min break also stabilized crack progression, compared to at least 2 h needed to reach the same effect without SMA wires.
Summary
Since its introduction in Madagascar in 1998, African swine fever (ASF) has severely affected national pig production and persists as a common disease in that country. Two of its natural ...hosts in the African continent, the bushpig (Potamochoerus larvatus) and tick vectors of the Ornithodoros moubata complex, are reported in west and central regions of the island. However, their role in the maintenance and transmission of the virus has been insufficiently studied. In this work, we tried to assess their potential role in the epidemiology of the disease in Madagascar, by assessing the levels of interaction between (i) ASF virus (ASFV) and bushpigs and (ii) between soft ticks and domestic and wild suids in north‐western Madagascar. Twenty‐seven sera and 35 tissue samples from bushpigs were collected and analysed for the presence of anti‐ASF antibodies and viral DNA. In addition, the sera from 27 bushpigs and 126 domestic pigs were analysed with an ELISA test for the detection of antibodies against salivary antigens from Ornithodoros ticks. No circulation of ASFV or anti‐ASFV antibodies nor anti‐tick antibodies were detected in bushpigs. However, seven of the domestic pig sera (5.6% of the total sample population) were antibody positive for O. moubata antigens. The probability of freedom from ASFV in the bushpig population using Bayesian statistical methods ranged between 73% and 84%. The probabilities of absence of anti‐tick antibodies in domestic and wild pigs were estimated at 63% and 71%, respectively. These preliminary results suggest that bushpigs are unlikely to play a significant role in the maintenance and transmission of ASFV in Madagascar. Nevertheless, further ASFV surveys are needed on that species to confirm this assumption. In addition, the presence of antibodies against O. moubata in domestic pigs suggests that soft ticks may be able to maintain ASFV within a domestic pig cycle in areas of Madagascar where they remain present.
The nature of atmospheric aerosols is extremely complex and often requires advanced analytical tools for the determination of its physical and chemical properties. In particular, the interaction of ...particles with atmospheric water is a complex function of both particle size and composition. The ability of a particle to grow in a humid environment can be measured by humidity tandem differential mobility analyzing techniques (H-TDMA). In this article, we present a new development combining thermo-desorption and humidification aerosol conditioning in series that allows to measure changes in the hygroscopic behavior of aerosol at 90% relative humidity (RH) after conditioning of the particle by thermo-desorption to a temperature between 25°C and 300°C. The main feature of this system, named Volatility Hygroscopic-Tandem Differential Mobility Analyzer (VH-TDMA), is to allow for rapid (10 minutes) series of scans to control particle response to 1-thermal conditioning, 2- RH increase to 90% and 3-a combination of both thermal and RH conditioning. The VH-TDMA is, therefore, suited to investigate particle ageing through a simple coupling of H-TDMA and V-TDMA performances.
The aim of the present article is to describe the instrument design and to validate its performances by focusing on the measurement of hygroscopic behavior of pure inorganic particles such as sodium chloride or ammonium sulfate, as well as internally mixed organic-inorganic particles. Based on laboratory experiments and applications to natural aerosols, we show that the VH-TDMA system can be used to investigate the hygroscopic properties of the non-volatile fraction of ambient sub-micrometer aerosols in the range of 20 to 150 nm and the influence of the more volatile fraction of the particle on hygroscopic growth.
Commingled yarns of reinforcing and thermoplastic fibres offer a potential for low-cost manufacturing of complex-shaped composite parts, due to reduced impregnation times and applied pressures during ...processing. In order to benefit from this competitive advantage, the process parameters governing consolidation must be controlled. In this study, a consolidation model, previously validated for unidirectional commingled yarn fabrics processed isothermally in a flat matched-die mould, is applied to three other processing techniques capable of producing complex-shaped composites. Tubes of braided commingled yarns were manufactured by bladder inflation moulding. Selectively reinforced polymeric parts were processed by compression–injection moulding. Stamp forming was also used to allow high-speed processing of commingled yarn-based laminates. Besides particular stamp forming cases, for which part deconsolidation occurred, the model predictions were in good agreement with the void content values obtained from specimens consolidated under different processing conditions. This suggests that the consolidation model can be successfully applied to a wide range of yarn architectures and processing techniques.
A design tool able to predict the residual stress state and dimensional stability of large complex shaped composite parts has been developed. It is based on a finite element model, using a ...three-dimensional anisotropic thermo-viscoelastic formulation. Asymmetric cross-ply laminates were manufactured in a ‘V-shape’ from non-crimp carbon fibre fabric reinforced epoxy for validation. A hybrid finite element mesh, containing both shell and solid elements was proposed as the solution to minimising the computational resources required. Results demonstrate that the approach is valid, that the effect of cooling rate on the predicted dimensional stability is significant but that the model over-predicts the experimentally observed part deformation.
The present work aims to enhance the interlaminar toughness of carbon/epoxy composites produced by RTM by modifying the resin with hyperbranched polymers (HBPs). A HBP content of 7.5% in the resin ...was selected as the best compromise between a slight loss in stiffness and a gain of 60% in fracture toughness. Composites manufactured with the modified resin did not show such improvement in terms of interlaminar shear strength when double cantilever beam (DCB) specimens were subjected to crack opening. In the case of composites made of pure epoxy, a value of
G
IC
=
600
J/m
2 was found, whereas for the modified resin based composite,
G
IC was equal to 750
J/m
2. Fibre pullout tests indicated that adhesion at the fibre–matrix interface was poor in case of the modified epoxy. Adding amine to the modified resin was shown to counterbalance this depreciation, raising
G
IC of the composite to 1400
J/m
2.
In tropical countries the diagnosis of viral infections of humans or animals is often hampered by the lack of suitable clinical material and the necessity to maintain a cold chain for sample ...preservation up to the laboratory. This study describes the use of filter papers for rapid sample collection, and the molecular detection and genotyping of viruses when stored over long periods at elevated temperatures. Infected blood was collected on filter papers, dried and stored at different temperatures (22, 32 and 37
°C) for various periods (up to 9 months). Two animal viruses, African swine fever, a large double-stranded DNA virus and Peste des Petits Ruminants, a negative single-stranded RNA virus, were used to validate the method. Filter papers with dried blood containing virus or control plasmid DNA were cut in small 5
mm
2 pieces and added directly to the PCR tube for conventional PCR. Nucleic acid from both viruses could still be detected after 3 months at 32
°C. Moreover, the DNA virus could be detected at least 9 months after conservation at 37
°C. PCR products obtained from the filter papers were sequenced and phylogenetic analysis carried out. The results were consistent with published sequences, demonstrating that this method can be used for virus genotyping.
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