A priori estimates for anti-symmetric solutions to a fractional Laplacian equation in a bounded domain

In this paper, we obtain a priori estimates for the set of anti-symmetric solutions to a fractional Laplacian equation in a bounded domain using a blowing-up and rescaling argument. In order to establish a contradiction to possible blow-ups, we apply a certain variation of the moving planes method in order to prove a monotonicity result for the limit equation after rescaling

Production and characterisation of novel phosphate glass fibre yarns, textiles, and textile composites for biomedical applications

This work presents manufacturing, processing and characterisation of the phosphate glass fibre (PGF) products for biomedical applications, including multifilament PGF strands, yarns and textiles, and PGF textile composites. The multifilament production of PGF strands was achieved using a 50-nozzle bushing. PGF yarns, with a linear density of 87 tex, a twist angle of 14° and a tensile strength of 0.29 N/tex, were produced by combining 8 fibre strands using the ring-spinning method. PGF textiles, with a width of 15 mm and a thickness of 0.36 mm, were prepared using an inkle loom. The maximum flexural strength and modulus of unidirectional (UD) composites with a fibre volume fraction of ~17% were 262 ± 11 MPa and 10.4 ± 0.2 GPa, respectively. PGF textile composites with a fibre volume fraction of ~21% exhibited mechanical properties of 176 ± 13 MPa for flexural strength and 8.6 ± 0.6 GPa for flexural modulus. Despite the UD and textile composites having almost an equivalent amount of fibres in the 0 direction, the crimp of the yarns was found to contribute to the significantly lower flexural properties of the textile composites in comparison with the unidirectional (UD) composites. Additionally, the processing conditions such as processing temperature and time were found to have a strong effect on the mechanical properties of the resultant composite products. The number-average molecular weight of PLA was also found to reduce by 13% and 19% after the production of PLA films and PLA plates, respectively, in comparison with the as-received PLA pellets

Source Apportionment of Gaseous and Particulate PAHs from Traffic Emission Using Tunnel Measurements in Shanghai, China

Understanding sources and contributions of gaseous and particulate PAHs from traffic-related pollution can provide valuable information for alleviating air contamination from traffic in urban areas. On-road sampling campaigns were comprehensively conducted during 2011–2012 in an urban tunnel of Shanghai, China. 2–3 rings PAHs were abundant in the tunnel\u27s gas and particle phases. Diagnostic ratios of PAHs were statistically described; several were significantly different between the gas and particle phases. Principal component analysis (PCA), positive matrix factorization (PMF), bivariate correlation analysis and multiple linear regression analysis (MLRA) were applied to apportion sources of gaseous and particulate PAHs in the tunnel. Main sources of the gaseous PAHs included evaporative emission of fuel, high-temperature and low-temperature combustion of fuel, accounting for 50–51%, 30–36% and 13–20%, respectively. Unburned fuel particles (56.4–78.3%), high-temperature combustion of fuel (9.5–26.1%) and gas-to-particle condensation (12.2–17.5%) were major contributors to the particulate PAHs. The result reflected, to a large extent, PAH emissions from the urban traffic of Shanghai. Improving fuel efficiency of local vehicles will greatly reduce contribution of traffic emission to atmospheric PAHs in urban areas. Source apportionment of PM10 mass was also performed based on the organic component data. The results showed that high-temperature combustion of fuel and gas-to-particle condensation contributed to 15–18% and 7–8% of PM10 mass, respectively, but 55–57% of the particle mass was left unexplained. Although the results from the PCA and PMF models were comparable, the PMF method is recommended for source apportionment of PAHs in real traffic conditions. In addition, the combination of multivariate statistical method and bivariate correlation analysis is a useful tool to comprehensively assess sources of PAHs

Ochronotic arthropathy effectively treated with total hip and total knee arthroplasty: a case report

Ochronosis is a rare autosomal recessive disorder of tyrosine metabolism characterized by multilevel spinal degeneration and arthritis of large weight-bearing joints, which is referred to as ochronotic arthropathy. In this case report, we describe diagnosis and treatment of ochronotic arthropathy in a patient who underwent total hip arthroplasty (THA) and total knee arthroplasty (TKA). The Harris hip score was 26 preoperatively and 45, 68, 76, 90, 92, and 94 at 1, 3, 6, 9, 11, and 14 months, respectively, postoperatively. The forgotten joint score (FJS) of the hip was 27.8, 52.8, 81.1, 89.0, 90.6, and 92.4 at 1, 3, 6, 9, 11, and 14 months, respectively, postoperatively. TKA was performed 8 months after THA. The Knee Society Score was 36 before TKA and 74, 82, and 90 at 1, 3, and 6 months, respectively, after TKA. The FJS of the knee was 36.6, 63.9, and 84.5 at 1, 3, and 6 months, respectively, after TKA. The patient’s knee range of motion returned to normal, with significant reduction in pain and improved satisfaction levels after TKA. THA and TKA can achieve good clinical outcomes in patients with ochronosis accompanied by severe joint pain

Novel bioresorbable textile composites for medical applications

Currently, phosphate glass fibre (PGF) reinforced composites are a potential solution for bone repairing due to sufficient mechanical properties and full bioresorbability. In this study, a small inkle-type loom for hand weaving facilitated the production of PGF in textile form. These PGF textiles, along with unidirectional (UD) fibre mats made from the same batch of yarns, were utilised to manufacture fully resorbable textile composites (T-C) and 0°/90° lay-up UD fibre reinforced composites (0/90-C). Retention of flexural properties and weight loss of the composites were evaluated during degradation in phosphate buffered saline (PBS) at 37°C for 28 days. The initial flexural strength values that were observed for the T-C and 0/90-C composites were ∼;176 MPa and ∼;137 MPa, whilst the modulus values were 8.6 GPa and 6.9 GPa, respectively. The higher flexural strength and modulus values for the T-C when compared to those of 0/90-C were attributed to the textile weaving manually, resulting in a biased fabric with a higher density of fibres in the warp direction. ∼;20% flexural strength and ∼;25% flexural modulus were maintained for all composites at the 28 day interval. For this study, the textile achievement will be the significant milestone on the research of bioresorbable PGFs reinforced composite in medical application, and important step on the industrial direction of bioresorbable medical device. © 2017 International Committee on Composite Materials. All rights reserved

The effect of intumescent mat on post-fire performance of carbon fibre reinforced composites

This study investigated the effect of intumescent mats (M1 and M2) with different compositions on the post-fire performance of carbon fibre reinforced composites. The sandwich structure was designed for composites where M1 (carbon fibre reinforced composite-M1) or M2 (carbon fibre reinforced composite-M2) mats were covered on the composite surface. A significant reduction in the peak heat release rate and total heat release was observed from the cone calorimetric data, and carbon fibre reinforced composite-M1 showed the lowest value of 148 kW/m2 and 29 MJ/m2 for peak heat release rate and total heat release, respectively. In addition, a minor influence on mechanical properties was observed due to the variation of composite thickness and resin volume in the composite. The post-fire properties of composite were characterised, and the M1 mat presented better retention of flexural strength and modulus. The feasibility of two-layer model was confirmed to predict the post-fire performance of composites and reduce the reliance on the large amounts of empirical data. © The Author(s) 2019

Structural, thermal, in vitro degradation and cytocompatibility properties of P2O5-B2O3-CaO-MgO-Na2O-Fe2O3 glasses

Borophosphate glasses with compositions of (48 − x)P2O5-(12 + x)B2O3-14CaO-20MgO-1Na2O-5Fe2O3 (where x = 0, 3, 8 mol%) were prepared via a melt-quenching process. The effects of replacing P2O5 with B2O3 on the structural, thermal, degradation properties and cytocompatibility were investigated. Fourier transform infrared (FTIR) spectroscopy analysis confirmed the existence of BO3 triangular units and BO4 tetrahedral units within all the glasses with an increase of B/P ratio from 0.25 to 0.5. The BO4 units within the glass structure were observed to cause an increase in density (ρ) as well as glass transition (Tg) temperature and to decrease the crystallisation temperature (Tc). A decrease in thermal stability which indicated by process window was also observed in the case of substitution of P2O5 with B2O3. Degradation analysis of the glasses indicated that the dissolution rate increased with the addition of B2O3. The decrease in the thermal stability and chemical durability were attributed to the increase of BO3 units, which could increase crystallisation tendency and be easily hydrolysed by solution. The effect of boron addition on the cytocompatibility of the glasses was analysed using Alamar Blue and alkaline phosphatase (ALP) assays and DNA quantification. MG63 osteosarcoma cells cultured in direct contact with the glass samples surface for 14 days showed better cytocompatibility, compared to the tissue culture plastic (TCP) control group. In summary, the glass formulation with 12 mol% B2O3 presented the best cytocompatibility and thermal stability, thus could be considered for continuous fibre fabrication in future research and downstream activities