Manufacturing of pre-impregnated discontinuous CF/PAEK composite

This is the final version. Freely available from ICCM via the link in this recordHigh temperature engineering thermoplastics such as the PAEK family of polymers, are now finding increased application in advanced composites structures. Polymers and polymer processing are at the heart of the manufacturing sector, with a huge number of uses. However, in many advanced applications, metals are chosen because conventional polymers either cannot deliver the required mechanical performance or are thermally vulnerable. PAEK can overcome these obstacles and are now transforming the landscape of materials usage, offering far more than just lightweight replacements for metals. Some PAEK’s can operate continuously at 260°C and many are resistant to ionising radiation, corrosion, abrasion and stress-fatigue, have low toxicity, and very importantly – because of their linear molecular structures – they are mechanically tough. Indeed when reinforced with carbon fibre, as part of a thermoplastic composite (TPC), their properties far outshine traditional thermoset matrix composites in terms of toughness, without loss of strength or stiffness, while significantly reducing production costs. Due to the above characteristics; unique to TPC only, these composites have found applications in most industry sectors, e.g. in aerospace: ducting, cable housings, bracketry, elevator tail sections and rudders, shear webs for localised reinforcement, seat frames and floor panels. PAEK carbon fibre moulding compounds are the latest TPC format, where material consists of short lengths of pre-impregnated discontinuous 25mm aligned carbon fibre tapes. These tapes or chips, present a major advantage over conventional prepreg sheets, in that they can flow and form to a mould, and potentially are far less labour intensive, making mass production of PAEK/ CF parts possible. The possibilities of PAEK/ CF tapes are only just starting to be explored, where the relationship between processing conditions and resulting composite properties is not yet defined. A major factor is the exposure of these compounds to extended thermal cycles during processing – which can be extremely detrimental to mechanical properties This work seeks to closely define the processing-properties relationship for these advanced materials and provide manufacturers and industry with the processing information required to control the key parameters during manufacture and thereby optimise resulting properties of moulded PAEK/ CF composites.Innovate U

The use of discontinuous PEEK/carbon fiber thermoplastic moulding compounds for thick-section componentry

This is the final version. Available on open access from Taylor & Francis via the DOI in this recordThe hot-pressing of discontinuous fiber moulding compounds (DFMCs) is an established way of forming geometrically complex components, however, it is not a simple process. Rapid and irreversible cure cycles hinder the use of thermoset resins, and thermoplastic resins offer inferior mechanical performance. The recent availability of DFMCs utilising a Polyether Ether Ketone (PEEK) matrix offer an alternative, combining the usability of thermoplastics with significantly enhanced mechanical properties. A novel manufacturing approach is proposed and investigated, in which virgin material is consolidated into multiple ‘pre-charges’ prior to pressing the final component, combating the limitations of DFMCs; loft, voidage and fiber orientation. Short beam shear tests were employed to assess the mechanical implications of laminating DFMCs, demonstrating minimal differences to a standard sample. Three-point bend tests assessed rudimentary orientation of fiber bundles, showing significantly improved mechanical performance at the cost of toughness. A novel method to determine the interlaminar shear modulus is also presented and successfully validated.Innovate U

Thermo-mechanical behaviour of composite moulding compounds at elevated temperatures

This is the author accepted manuscript. The final version is available from Elsevier via the DOI in this record.The use of fibre-reinforced polymer composites as a lightweight metal replacement for automotive componentry is constantly expanding into new and more challenging application areas (e.g. whole range of under-bonnet, exhaust applications and other automotive components), where service temperatures are not expected to go beyond 150°C. This study seeks to provide some useful baseline data on the bending stiffness performance of a large range of commercially available composite moulding compounds, in order to provide guidance in selecting appropriate materials for various applications requiring higher operating temperatures, where retention of bending stiffness is a key parameter. Whilst glass transition data can give some indication, this study seeks to go further. Three point bending flexural tests and Dynamic Mechanical Analysis were used to investigate and compare properties both at ambient and 150°C comparing various composite systems, particularly phenolics, one of the fastest-growing systems in the thermoset moulding compounds market.Innovate U

The karyotype of three Brazilian Terrarana frogs (Amphibia, Anura) with evidence of a new Barycholos species

A recent substantial rearrangement of the 882 described eleutherodactyline frog species has considerably improved the understanding of their systematics. Nevertheless, many taxonomic aspects of the South American eleutherodactyline species remain unknown and require further investigation using morphological, cytogenetic and molecular approaches. In this work, the karyotypes of the Brazilian species Ischnocnema juipoca (Atibaia and Campos do Jordão, SP), Barycholos cf. ternetzi (Uberlândia, MG, and Porto Nacional, TO), and Pristimantis crepitans (Chapada dos Guimarães and São Vicente, MT) were analyzed using Giemsa staining, Ag-NOR labeling, and C-banding techniques. All individuals had a diploid number of 22 chromosomes, but the Fundamental Numbers were different among species. The herein described low chromosome number of Pristimantis crepitans is unique within this genus, suggesting that cytogenetically this species is not closely related either to its congeneric species or to Ischnocnema. In addition, karyotype differences, mainly in the NOR position, clearly distinguished the two Barycholos populations, besides indicating the existence of a so far undescribed species in this genus. A taxonomic review could clarify the systematic position of P. crepitans and verify the hypothetic new Barycholos species

The socio-technical organisation of community pharmacies as a factor in the Electronic Prescription Service Release Two implementation: a qualitative study

Background The introduction of a new method of transmitting prescriptions from general practices to community pharmacies in England (Electronic Prescription Service Release 2 (EPS2)) has generated debate on how it will change work practice. As EPS2 will be a key technical element in dispensing, we reviewed the literature to find that there were no studies on how social and technical elements come together to form work practice in community pharmacies. This means the debate has little point of reference. Our aim therefore was to study the ways social and technical elements of a community pharmacy are used to achieve dispensing through the development of a conceptual model on pharmacy work practice, and to consider how a core technical element such the EPS2 could change work practice. Method We used ethnographic methods inclusive of case-study observations and interviews to collect qualitative data from 15 community pharmacies that were in the process of adopting or were soon to adopt EPS2. We analysed the case studies thematically and used rigorous multi-dimensional and multi-disciplinary interpretive validation techniques to cross analyse findings. Results In practice, dispensing procedures were not designed to take into account variations in human and technical integration, and assumed that repetitive and collective use of socio-technical elements were at a constant. Variables such as availability of social and technical resources, and technical know-how of staff were not taken into account in formalised procedures. Yet community pharmacies were found to adapt their dispensing in relation to the balance of social and technical elements available, and how much of the social and technical elements they were willing to integrate into dispensing. While some integrated as few technical elements as possible, some depended entirely on technical artefacts. This pattern also applied to the social elements of dispensing. Through the conceptual model development process, we identified three approaches community pharmacies used to appropriate procedures in practice. These were ‘technically oriented’, ‘improvising’ or ‘socially oriented’. Conclusion We offer a model of different work approaches community pharmacies use to dispense, which suggests that when adopting a core technical element such as the EPS2 system of dispensing there could be variations in its successful adoption. Technically oriented pharmacies might find it easiest to integrate a similar artefact into work practice although needs EPS2 to synchronise effectively with existing technologies. Pharmacies adopting an improvising-approach have the potential to improve how they organise dispensing through EPS2 although they will need to improve how they apply their operating procedures. Socially oriented pharmacies will need to dramatically adapt their approach to dispensing since they usually rely on few technical tools

A Meta-Analysis of Interleukin-8 -251 Promoter Polymorphism Associated with Gastric Cancer Risk

Background: Potential functional allele A/T single nucleotide polymorphism (SNP) of Interleukin 8 (IL-8) promoter-251has been implicated in gastric cancer risk. Methods: We aimed to explore the role of A/T SNP of IL-8-251 in the susceptibility to gastric cancer through a systematic review and meta-analysis. Each initially included article was scored for quality appraisal. Desirable data were extracted and registered into databases. Eighteen studies were ultimately eligible for the meta-analysis of IL-8- 251 A/T SNP. We adopted the most probably appropriate genetic model (codominant model). Potential sources of heterogeneity were sought out via stratification and sensitivity analyses, and publication biases were estimated. Results: Between IL-8-251 AA genotype with gastric cancer risk, statistically significant association could be noted with overall gastric cancer, evidently noted in Asians, witnessed in high quality subgroup, and apparently noted in intestinal-type gastric cancer. Conclusions: Our meta-analysis indicates that IL-8-251 AA genotype is associated with the overall risk of developing gastric cancer and may seem to be more susceptible to overall gastric cancer in Asian populations. IL-8-251 AA genotype is more associated with the intestinal-type gastric cancer. IL-8-251 AA genotype is not associated with Helicobacter Pylori infection status in our meta-analysis

Comparative Analysis of Dengue and Zika Outbreaks Reveals Differences by Setting and Virus.

The pacific islands of Micronesia have experienced several outbreaks of mosquito-borne diseases over the past decade. In outbreaks on small islands, the susceptible population is usually well defined, and there is no co-circulation of pathogens. Because of this, analysing such outbreaks can be useful for understanding the transmission dynamics of the pathogens involved, and particularly so for yet understudied pathogens such as Zika virus. Here, we compared three outbreaks of dengue and Zika virus in two different island settings in Micronesia, the Yap Main Islands and Fais, using a mathematical model of transmission dynamics and making full use of commonalities in disease and setting between the outbreaks. We found that the estimated reproduction numbers for Zika and dengue were similar when considered in the same setting, but that, conversely, reproduction number for the same disease can vary considerably by setting. On the Yap Main Islands, we estimated a reproduction number of 8.0-16 (95% Credible Interval (CI)) for the dengue outbreak and 4.8-14 (95% CI) for the Zika outbreak, whereas for the dengue outbreak on Fais our estimate was 28-102 (95% CI). We further found that the proportion of cases of Zika reported was smaller (95% CI 1.4%-1.9%) than that of dengue (95% CI: 47%-61%). We confirmed these results in extensive sensitivity analysis. They suggest that models for dengue transmission can be useful for estimating the predicted dynamics of Zika transmission, but care must be taken when extrapolating findings from one setting to another

Schedule-selective biochemical modulation of 5-fluorouracil in advanced colorectal cancer – a phase II study

BACKGROUND: 5-fluorouracil remains the standard therapy for patients with advanced/metastatic colorectal cancer. Pre-clinical studies have demonstrated the biological modulation of 5-fluorouracil by methotrexate and leucovorin. This phase II study was initiated to determine the activity and toxicity of sequential methotrexate – leucovorin and 5-fluorouracil chemotherapy in patients with advanced colorectal cancer. METHODS: Ninety-seven patients with metastatic colorectal cancer were enrolled onto the study. Methotrexate – 30 mg/m(2) was administered every 6 hours for 6 doses followed by a 2 hour infusion of LV – 500 mg/m(2). Midway through the leucovorin infusion, patients received 5-fluorouracil – 600 mg/m(2). This constituted a cycle of therapy and was repeated every 2 weeks until progression. RESULTS: The median age was 64 yrs (34–84) and the Eastern Cooperative Group Oncology performance score was 0 in 37%, 1 in 55% and 2 in 8% of patients. Partial and complete responses were seen in 31% of patients with a median duration of response of 6.4 months. The overall median survival was 13.0 months. The estimated 1-year survival was 53.7%. Grade III and IV toxic effects were modest and included mucositis, nausea and vomiting. CONCLUSIONS: This phase II study supports previously reported data demonstrating the modest clinical benefit of 5-FU modulation utilizing methotrexate and leucovorin in patients with metastatic colorectal cancer. Ongoing studies evaluating 5-fluorouracil modulation with more novel agents (Irinotecan and/or oxaliplatin) are in progress and may prove encouraging

Postpartum-specific anxiety as a predictor of infant-feeding outcomes and perceptions of infant-feeding behaviours: new evidence for childbearing specific measures of mood

Studies of pregnancy-specific anxiety suggest that it is a distinct construct which predicts perinatal outcomes more effectively than other general measures of anxiety. In response, a novel measure of postpartum-specific anxiety (PSAS) has been developed and validated, but it is not yet clear whether it possesses the same predictive power as its pregnancy-specific counterparts. The aim of this short-term prospective study was to (a) test the predictive validity of the PSAS in the context of one specific perinatal outcome, infant-feeding, and (b) examine whether the PSAS may be more efficacious at predicting infant-feeding outcomes and behaviours than the more commonly used general measures. Eight hundred mothers of infants aged between 0 and 6 months completed the PSAS alongside general measures of anxiety and depression at baseline. A subsample (n = 261) returned to complete a follow-up questionnaire examining infant-feeding outcomes and behaviours two weeks later. Hierarchical regression models revealed that the PSAS was associated with lower odds of breastfeeding exclusively, and breastfeeding in any quantity in the first 6 months postpartum. PSAS scores were also significantly associated with infant-feeding behaviours including a lower perceived enjoyment of food, and greater perceived food responsiveness and satiety responsiveness in the infant. As hypothesised, the PSAS was a stronger predictor of infant-feeding outcomes and behaviours than general anxiety and depression. The findings provide evidence for the predictive validity of the PSAS and call for the use of childbearing specific measures of mood when attempting to predict perinatal outcomes. Replication of these findings across other indices of maternal and infant health is now necessary

Temperature, Viral Genetics, and the Transmission of West Nile Virus by Culex pipiens Mosquitoes

The distribution and intensity of transmission of vector-borne pathogens can be strongly influenced by the competence of vectors. Vector competence, in turn, can be influenced by temperature and viral genetics. West Nile virus (WNV) was introduced into the United States of America in 1999 and subsequently spread throughout much of the Americas. Previously, we have shown that a novel genotype of WNV, WN02, first detected in 2001, spread across the US and was more efficient than the introduced genotype, NY99, at infecting, disseminating, and being transmitted by Culex mosquitoes. In the current study, we determined the relationship between temperature and time since feeding on the probability of transmitting each genotype of WNV. We found that the advantage of the WN02 genotype increases with the product of time and temperature. Thus, warmer temperatures would have facilitated the invasion of the WN02 genotype. In addition, we found that transmission of WNV accelerated sharply with increasing temperature, T, (best fit by a function of T4) showing that traditional degree-day models underestimate the impact of temperature on WNV transmission. This laboratory study suggests that both viral evolution and temperature help shape the distribution and intensity of transmission of WNV, and provides a model for predicting the impact of temperature and global warming on WNV transmission