4,509 research outputs found

    Mechanical Recycling of Automotive Composites for Use as Reinforcement in Thermoset Composites

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    The aim of this research was to investigate the potential use of recycled glass fibre composite materials as a replacement for virgin reinforcing materials in new thermoset composites. Specifically the closed-loop mechanical recycling of composites used heavily in the automotive sector known as dough and sheet moulding composites, DMC and SMC respectively, are investigated. The recycling of glass reinforced thermoset polymer composite materials has been an area of investigation for many years and composites used in the automotive industry are of particular interest due to legislative and social pressures on the industry. The mechanical recycling process and then collection of useful fibrous grades of recycled materials, recyclate, by a novel air separation technique were investigated first. The properties of these recyclate fibres were characterised and compared directly with the properties of virgin glass fibres they were to be used to replace. Single fibre tensile tests were employed to compare the strengths of the fibres and single fibre pull-out tests were used to investigate the strength of the interface between the fibres and a polyester matrix. These tests showed the recyclate fibres to be weaker and have a poorer interface with the polyester matrix than the virgin glass fibres. Understanding the properties of the recyclate materials meant their reformulation into new composites could be carefully considered for the production of new high performance materials. Two grades of the collected recyclate materials were then reformulated in to new DMC and SMC composites, replacing percentages of the virgin glass fibre reinforcement. The mechanical properties of the resulting manufactured composites were characterised throughout for direct comparison against one another and an unmodified control material, using both three-point flexural tests and Charpy impact tests. Through the modification of existing manufacturing techniques and the development of novel production equipment it has been possible to successfully manufacture both DMC and SMC composites with the recyclate materials used to replace virgin glass fibres. Virgin glass fibres have successfully been replaced by recyclate materials without disrupting standard production techniques and with minimal reduction of the mechanical properties of the resulting composites. As the loadings of recyclate materials used were greatly increased both the flexural and impact strengths were significantly degraded and it was found that chemical modification of the composite could be used to improve these formulations. It has been shown that the recyclate materials should be considered and treated as a distinct reinforcing ingredient, separately from the remaining virgin glass fibres

    Trial of Ultrasound guided carpal tunnel release versus Traditional Open Release (TUTOR)

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    BACKGROUND: Carpal tunnel release (CTR) is a surgical treatment option for patients with carpal tunnel syndrome (CTS) symptoms that are unresponsive to conservative treatment. Most patients experience symptomatic relief after CTR regardless of the surgical technique. However, direct comparisons of the safety and effectiveness between CTR surgical techniques are limited. The purpose of this randomized controlled trial is to compare the safety and effectiveness of CTR with ultrasound guidance (CTR-US) versus mini-open CTR (mOCTR) in subjects with symptomatic CTS. DESIGN AND METHODS: TUTOR (Trial of Ultrasound guided CTR versus Traditional Open Release) is a randomized controlled trial in which 120 subjects at up to 12 sites in the United States will be randomized (2:1) to receive CTR-US or mOCTR. The primary endpoint of the study is the percentage of patients who return to normal daily activities within 3 days of the procedure. Secondary endpoints of the study are median time to return to normal daily activities, percentage of patients who return to work within 3 days of the procedure, median time to return to work, Boston Carpal Tunnel Questionnaire Symptom Severity Scale (BCTQ-SSS) change score at 3 months, BCTQ Functional Status Scale (BCTQ-FSS) change score at 3 months, Numeric Pain Scale change score at 3 months, EuroQoL-5 Dimension 5-Level (EQ-5D-5L) change score at 3 months, and the incidence of device- or procedure-related adverse events at 3 months. Patient follow-up in this trial will continue for 1 year. ETHICS AND DISSEMINATION: This study was approved by a central institutional review board and ongoing trial oversight will be provided by a data safety monitoring board (DSMB). The authors intend to report the results of this trial at medical conferences and peer-reviewed journals. The outcomes of TUTOR will have important clinical and economic implications for all stakeholders involved in treating patients with CTS. STUDY REGISTRATION: ClinicalTrials.gov (https://clinicaltrials.gov): NCT05405218. LEVEL OF EVIDENCE: 1

    Multicenter randomized trial of carpal tunnel release with ultrasound guidance versus mini-open technique

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    BACKGROUND: Comparative studies of carpal tunnel release with ultrasound guidance (CTR-US) vs. mini-open CTR (mOCTR) are limited, prompting development of this randomized trial to compare efficacy and safety of these techniques. RESEARCH DESIGN AND METHODS: Patients were randomized (2:1) to CTR-US or mOCTR, treated by experienced hand surgeons (median previous cases: 12 CTR-US; 1000 mOCTR), and followed for 3 months. RESULTS: Among 149 randomized patients, 122 received CTR-US ( CONCLUSIONS: The efficacy and safety of CTR-US were comparable to mOCTR despite less previous surgical experience with CTR-US. The choice of CTR technique should be determined by shared decision-making between patient and physician. CLINICAL TRIAL REGISTRATION: www.clinicaltrials.gov identifier is NCT05405218

    Large-scale genome-wide association studies and meta-analyses of longitudinal change in adult lung function.

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    BACKGROUND: Genome-wide association studies (GWAS) have identified numerous loci influencing cross-sectional lung function, but less is known about genes influencing longitudinal change in lung function. METHODS: We performed GWAS of the rate of change in forced expiratory volume in the first second (FEV1) in 14 longitudinal, population-based cohort studies comprising 27,249 adults of European ancestry using linear mixed effects model and combined cohort-specific results using fixed effect meta-analysis to identify novel genetic loci associated with longitudinal change in lung function. Gene expression analyses were subsequently performed for identified genetic loci. As a secondary aim, we estimated the mean rate of decline in FEV1 by smoking pattern, irrespective of genotypes, across these 14 studies using meta-analysis. RESULTS: The overall meta-analysis produced suggestive evidence for association at the novel IL16/STARD5/TMC3 locus on chromosome 15 (P  =  5.71 × 10(-7)). In addition, meta-analysis using the five cohorts with ≥3 FEV1 measurements per participant identified the novel ME3 locus on chromosome 11 (P  =  2.18 × 10(-8)) at genome-wide significance. Neither locus was associated with FEV1 decline in two additional cohort studies. We confirmed gene expression of IL16, STARD5, and ME3 in multiple lung tissues. Publicly available microarray data confirmed differential expression of all three genes in lung samples from COPD patients compared with controls. Irrespective of genotypes, the combined estimate for FEV1 decline was 26.9, 29.2 and 35.7 mL/year in never, former, and persistent smokers, respectively. CONCLUSIONS: In this large-scale GWAS, we identified two novel genetic loci in association with the rate of change in FEV1 that harbor candidate genes with biologically plausible functional links to lung function

    Asymmetries in adaptive optics point spread functions

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    An explanation for the origin of asymmetry along the preferential axis of the PSF of an AO system is developed. When phase errors from high altitude turbulence scintillate due to Fresnel propagation, wavefront amplitude errors may be spatially offset from residual phase errors. These correlated errors appear as asymmetry in the image plane under the Fraunhofer condition. In an analytic model with an open-loop AO system, the strength of the asymmetry is calculated for a single mode of phase aberration, which generalizes to two dimensions under a Fourier decomposition of the complex illumination. Other parameters included are the spatial offset of the AO correction, which is the wind velocity in the frozen flow regime multiplied by the effective AO time delay, and propagation distance or altitude of the turbulent layer. In this model, the asymmetry is strongest when the wind is slow and nearest to the coronagraphic mask when the turbulent layer is far away, such as when the telescope is pointing low towards the horizon. A great emphasis is made about the fact that the brighter asymmetric lobe of the PSF points in the opposite direction as the wind, which is consistent analytically with the clarification that the image plane electric field distribution is actually the inverse Fourier transform of the aperture plane. Validation of this understanding is made with observations taken from the Gemini Planet Imager, as well as being reproducible in end-to-end AO simulations

    Using genetics to test the causal relationship of total adiposity and periodontitis: Mendelian randomization analyses in the Gene-Lifestyle Interactions and Dental Endpoints (GLIDE) Consortium

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    Background: The observational relationship between obesity and periodontitis is widely known, yet causal evidence is lacking. Our objective was to investigate causal associations between periodontitis and body mass index (BMI).Methods: We performed Mendelian randomization analyses with BMI-associated loci combined in a genetic risk score (GRS) as the instrument for BMI. All analyses were conducted within the Gene-Lifestyle Interactions and Dental Endpoints (GLIDE) Consortium in 13 studies from Europe and the USA, including 49 066 participants with clinically assessed (seven studies, 42.1% of participants) and self-reported (six studies, 57.9% of participants) periodontitis and genotype data (17 672/31 394 with/without periodontitis); 68 761 participants with BMI and genotype data; and 57 871 participants (18 881/38 990 with/without periodontitis) with data on BMI and periodontitis.Results: In the observational meta-analysis of all participants, the pooled crude observational odds ratio (OR) for periodontitis was 1.13 [95% confidence interval (CI): 1.03, 1.24] per standard deviation increase of BMI. Controlling for potential confounders attenuated this estimate (OR = 1.08; 95% CI:1.03, 1.12). For clinically assessed periodontitis, corresponding ORs were 1.25 (95% CI: 1.10, 1.42) and 1.13 (95% CI: 1.10, 1.17), respectively. In the genetic association meta-analysis, the OR for periodontitis was 1.01 (95% CI: 0.99, 1.03) per GRS unit (per one effect allele) in all participants and 1.00 (95% CI: 0.97, 1.03) in participants with clinically assessed periodontitis. The instrumental variable meta-analysis of all participants yielded an OR of 1.05 (95% CI: 0.80, 1.38) per BMI standard deviation, and 0.90 (95% CI: 0.56, 1.46) in participants with clinical data.Conclusions: Our study does not support total adiposity as a causal risk factor for periodontitis, as the point estimate is very close to the null in the causal inference analysis, with wide confidence intervals

    Genetic risk and a primary role for cell-mediated immune mechanisms in multiple sclerosis.

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    Multiple sclerosis is a common disease of the central nervous system in which the interplay between inflammatory and neurodegenerative processes typically results in intermittent neurological disturbance followed by progressive accumulation of disability. Epidemiological studies have shown that genetic factors are primarily responsible for the substantially increased frequency of the disease seen in the relatives of affected individuals, and systematic attempts to identify linkage in multiplex families have confirmed that variation within the major histocompatibility complex (MHC) exerts the greatest individual effect on risk. Modestly powered genome-wide association studies (GWAS) have enabled more than 20 additional risk loci to be identified and have shown that multiple variants exerting modest individual effects have a key role in disease susceptibility. Most of the genetic architecture underlying susceptibility to the disease remains to be defined and is anticipated to require the analysis of sample sizes that are beyond the numbers currently available to individual research groups. In a collaborative GWAS involving 9,772 cases of European descent collected by 23 research groups working in 15 different countries, we have replicated almost all of the previously suggested associations and identified at least a further 29 novel susceptibility loci. Within the MHC we have refined the identity of the HLA-DRB1 risk alleles and confirmed that variation in the HLA-A gene underlies the independent protective effect attributable to the class I region. Immunologically relevant genes are significantly overrepresented among those mapping close to the identified loci and particularly implicate T-helper-cell differentiation in the pathogenesis of multiple sclerosis
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