Repeated impact of simulated hail ice on glass fibre composite materials

Wind turbine blade damage, particularly leading edge erosion, is a significant problem faced by the renewable energy industry. Wind turbines are subject to a wide range of environmental factors during a 20 + year lifespan, with hailstones often touted as a key contributor to the deterioration of the blade profile. An experimental campaign was carried out to investigate the effects of repeated impact of smaller diameter simulated hail ice (SHI) on composite materials, to correspond to those most prevalent at wind farm locations. Hailstones of four different diameters (5 mm, 10 mm, 15 mm and 20 mm) were fired at velocities in the range of 50 ms −1 to 95 ms −1. Samples used for experimentation were manufactured from triaxial stitched glass fibre [0°/−45°/+45°] and epoxy resin. Damage was evaluated in terms of sample mass loss and microscopy of the composite surface. For all examples, mass loss was negligible and optical microscopy showed little evidence of surface damage. Surface degradation was discernible under scanning electron microscopy for the larger diameter SHI (≥15mm), with projectile velocity a notable factor in the extent of the damage. Even for large numbers of impacts, there was little noteworthy damage caused by smaller, more prevalent SHI (≤10mm). This suggests that hail is not a direct cause of wind turbine blade erosion

Studies on the purine and pyrimidine derivatives in animal tissues and in cell nuclei

Abstract Not Provided

The development and ultrastructure of intergeneric nuclear transfer embryos using ovine ooplasm.

This thesis encompasses work that aimed to further understand genomic reprogramming, an event crucial in obtaining development in cloned embryos produced by somatic cell nuclear transfer (SCNT). An increasing number of different mammalian species have been cloned using nuclear transfer technology since Dolly the cloned sheep was first successfully produced. However, the biological mechanisms involved in the process of nuclear reprogramming are yet to be fully described. At the centre of this study was an intergeneric SCNT model, which was implemented to determine whether reprogramming factors are conserved across genera. The interaction between donor nucleus and recipient ooplasm was characterised with regard to developmental potential, timing of genome activation, nucleolus formation, and expression of significant proteins. In initial studies, fusion parameters of the intergeneric SCNT procedure were optimised for the ovine cytoplast and porcine donor granulosa cell. Cell fusion and lysis percentages were determined over a range of electrical pulse voltage, duration and repetition. The optimal electrofusion settings were a single DC pulse of 1.5 kV/cm for 20 usec following a 2 sec 400 kHz alignment pulse. In addition, it was demonstrated that ovine oocytes were sensitive to electric stimulation to the extreme that oocyte activation would occur no matter how low the voltage. The practical significance was that it would not be possible to implement a fusion before activation protocol. The ability of the ooplasm of one species to replicate chromosomes and support early embryo cleavage was determined in a preliminary experiment where intergeneric embryos were produced by SCNT using bovine and ovine foetal fibroblasts, and ovine ooplasm. After their construction, the embryos were allowed to develop for 7 days in vitro and the developmental stage determined by Hoechst staining and nuclei counting. In addition, chromosome spreads of the ovine and bovine somatic foetal fibroblast cell lines used in SCNT, as well as the intra- and intergeneric SCNT embryos were prepared to determine whether the ovine ooplasm was replicating the chromosomes according to the karyotype of the donor nucleus. The somatic cells were karyotyped with 54 and 60 chromosomes counted for ovine and bovine cells respectively. Bovine-ovine embryos were characterised as having a bovine karyotype as distinct from an ovine karyotype, due to the presence of only two metacentric chromosomes as compared with six that are found in the latter. These preliminary results indicated that bovine nuclei obtained from foetal fibroblast cells could initiate early pre-implantation embryo development with the support of ovine oocyte cytoplasm. The development of a proportion (33%) of ovine-ovine intrageneric SCNT embryos beyond the 16-cell stage indicated that an extensive characterisation of an intergeneric model could be performed satisfactorily. It was hypothesised that the ovine ooplasm would possess the ability to direct in vitro preimplantation embryo development after nuclear transfer using donor nuclei from a different genus, as has been demonstrated in studies using bovine and rabbit ooplasm. In this study, intergeneric SCNT embryos were constructed by the separate fusion of porcine and bovine cells with ovine cytoplasts (bovine-ovine and porcine-ovine respectively), cultured in vitro and the developmental characteristics compared with ovine-ovine SeNT embryos as well as ovine in vitro produced (IVP) embryos. These four groups of embryos were sampled to determine embryo cell numbers at 24, 36, 48, 72, 96, 120 and 168 h post-activation to compare development over time. Despite cleaving normally and undergoing the first three cleavage divisions at a rate comparable with ovine-ovine SCNT embryos, a major block in development occurred in the intergeneric embryos at the 8-16 cell stage. Consequently, no blastocyst formation was obtained as observed for the IVP and ovine-ovine SCNT controls. These results indicate that unlike the rabbit and bovine ooplasm, the ovine ooplasm is not suitable for intergeneric reprogramming of somatic nuclei from another genus, at least of porcine or bovine origin. To determine the effect of a less differentiated donor nucleus on intergeneric developmental potential, embryonic cell nuclear transfer (ECNT) was conducted in a separate experiment by fusing pluripotent bovine and ovine donor cells (obtained from day-4 preimplantation embryos) to ovine cytoplasts. After 7 days of culture, the cell number of embryos was determined by Hoechst staining and fluorescent observation. Despite observing a single bovine-ovine blastocyst (4.8%), the developmental block remained at the 8-16 cell stage of development. This outcome indicates that a less differentiated nucleus does not increase intergeneric developmental capability. It is well documented that the ooplasm supplies a large amount of mRNA and protein to the newly formed embryo, crucial for normal development leading up to the major activation of the embryonic genome. However, the interaction between the ooplasm as compared with the donor nucleus in SCNT embryos during this developmental period is poorly understood. This intergeneric SCNT model provided an opportunity to determine the role of the ooplasm on nucleolus formation, which is a marker for genome activation. Ultrastructural evidence was obtained that indicates the ovine ooplasm directs the initial assembly of the nucleolus independent of the species of the nuclear donor. Intergeneric porcine-ovine SCNT and intrageneric ovine-ovine SCNT embryos were constructed and the nucleolus ultrastructure and nucleolus associated rRNA synthesis examined in 1-,2-,4-, early 8-, late 8-and 16-cell embryos using transmission electron microscopy (TEM) and light microscopical autoradiography. Intergeneric porcine-ovine SCNT embryos exhibited nucleolar precursor bodies (NPBs) of an ovine (ruminant) ultrastructure, but no active rRNA producing fibrillogranular nucleoli at any of the stages. Unusually, cytoplasmic organelles were located inside the nucleus of two porcineovine SCNT embryos. The ovine-ovine SCNT embryos, on the other hand, revealed fibrillogranular nucleoli in 16-cell embryos. In parallel, autoradiographic labelling over the nucleoplasm and, in particular, the nulcleoli was detected. Bovine-ovine SCNT embryos at the 8-cell stage were examined for nucleolar morphology and exhibited ruminant-type NPBs as well as structures that appeared to comprise of broken down fibrillar material, perhaps formerly of nucleolar origin from the donor cell. These observations indicate that factors within the ovine ooplasm are playing a role in the initial assembly of the embryonic nucleolus in intrageneric SCNT embryos. To further characterise nucleolus formation, immunocytochemical localisation by confocal microscopy of nucleolin, fibrillarin and RNA polymerase, three key proteins involved in processing rRNA transcripts, was performed on early 8-, late 8- and 16-cell embryos for ovineovine and porcine-ovine SCNT embryos. Nucleolin was localised throughout the nucleoplasm for all developmental stages examined in porcine-ovine and ovine-ovine SCNT embryos and, in particular, intensity around the presumptive nucleolar compartments in the later developmental stages. Fibrillarin and RNA polymerase I, on the other hand, were not detected in any ovineovine or porcine-ovine SCNT embryos or ovine IVP controls, although both proteins were detected in control bovine IVP blastocysts. This result indicates that the antifibrillarin and anti-RNA polymerase I were not compatible with the ovine form of these respective proteins. As nucleolin is not present in porcine in vivo embryos before the major activation of the embryonic genome, its presence in porcine-ovine SCNT embryo nucleus indicates that nucleolin is derived from the abundant protein and mRNA stored in the ovine ooplasm. The intergeneric SCNT model established in this thesis demonstrates that the ovine ooplasm lacks the ability to support embryonic development beyond the 16-cell stage. The TEM and autoradiographical studies, in combination with the protein immunocytochemistry study, confirmed that these embryos are unable to undergo the major activation of the embryonic genome, and that the ooplasm influences the initial nucleolar assembly in these embryos.Thesis (Ph.D.) -- University of Adelaide, School of Agriculture and Wine, 200

No such thing as bad publicity? A quantitative content analysis of print media representations of primary care out-of-hours services

Objective: To explore how out-of-hours primary healthcare services (OOHS) are represented in UK national newspapers, focusing on content and tone of reporting and the use of personal narratives to frame stories. Design: A retrospective cross-sectional quantitative content analysis of articles published in 2005, 2010 and 2015. Data sources: Nexis database used to search 10 UK national newspapers covering quality, middle-market and tabloid publications. Inclusion/exclusion criteria: All articles containing the terms ‘out-of-hours’ (≥3 mentions per article) or (‘NHS 24’ OR ‘NHS 111’ OR ‘NHS Direct’) AND ‘out-of-hours’ (≥1 mention per article) were included. Letters, duplicate news items, opinion pieces and articles without a substantial portion of the story (>50% of an article’s word count, as judged by researchers) concerning OOHS were excluded. Results: 332 newspaper articles were identified: 113 in 2005 (34.1%), 140 in 2010 (42.2%) and 79 in 2015 (23.8%). Of these, 195 (58.7%) were in quality newspapers, 99 (29.8%) in middle-market and 38 (11.3%) in tabloids. The most commonly reported themes were OOHS organisation, personal narratives and telephone triage. Stories about service-level crises and personal tragedy, including unsafe doctors and missed or delayed identification of rare conditions, predominated. The majority of articles (252, 75.9%) were negative in tone. This was observed for all included newspapers and by publication genre; middle-market newspapers had the highest percentage of negative articles (Pearson χ2=35.72, p<0.001). Articles presented little supporting contextual information, such as call rates per annum, or advice on how to access OOHS. Conclusion: In this first reported analysis of UK national newspaper coverage of OOHS, media representation is generally negative in tone, with frequent reports of ‘negative exemplars’ of OOHS crises and fatal individual patient cases with little or no contextualisation. We present recommendations for the future reporting of OOHS, which could apply to the reporting of healthcare services more generally

What do we know about demand, use and outcomes in primary care out-of-hours services? A systematic scoping review of international literature

This study was funded by the Scottish Government through the Primary Care Division and Health Improvement Scotland.Objective To synthesise international evidence for demand, use and outcomes of primary care out-of-hours health services (OOHS). Design Systematic scoping review. Data sources CINAHL; Medline; PsyARTICLES; PsycINFO; SocINDEX; and Embase from 1995 to 2019. Study selection English language studies in UK or similar international settings, focused on services in or directly impacting primary care. Results 105 studies included: 54% from mainland Europe/Republic of Ireland; 37% from UK. Most focused on general practitioner-led out-of-hours cooperatives. Evidence for increasing patient demand over time was weak due to data heterogeneity, infrequent reporting of population denominators and little adjustment for population sociodemographics. There was consistent evidence of higher OOHS use in the evening compared with overnight, at weekends and by certain groups (children aged 65, women, those from socioeconomically deprived areas, with chronic diseases or mental health problems). Contact with OOHS was driven by problems perceived as urgent by patients. Respiratory, musculoskeletal, skin and abdominal symptoms were the most common reasons for contact in adults; fever and gastrointestinal symptoms were the most common in the under-5s. Frequent users of daytime services were also frequent OOHS users; difficulty accessing daytime services was also associated with OOHS use. There is some evidence to suggest that OOHS colocated in emergency departments (ED) can reduce demand in EDs. Conclusions Policy changes have impacted on OOHS over the past two decades. While there are generalisable lessons, a lack of comparable data makes it difficult to judge how demand has changed over time. Agreement on collection of OOHS data would allow robust comparisons within and across countries and across new models of care. Future developments in OOHS should also pay more attention to the relationship with daytime primary care and other services.Publisher PDFPeer reviewe

Acute plate fixation of displaced midshaft clavicular fractures is not associated with earlier return of normal shoulder function when union is achieved

Aims: It is unclear whether acute plate fixation facilitates earlier return of normal shoulder function following a displaced mid-shaft clavicular fracture compared with nonoperative management when union occurs. The primary aim of this study was to establish whether acute plate fixation was associated with a greater return of normal shoulder function when compared with nonoperative management in patients who unite their fractures. The secondary aim was to investigate whether there were identifiable predictors associated with return of normal shoulder function in patients who achieve union with nonoperative management. Methods: Patient data from a randomized controlled trial were used to compare acute plate fixation with nonoperative management of united fractures. Return of shoulder function was based on the age- and sex-matched Disabilities of the Arm, Shoulder and Hand (DASH) scores for the cohort. Independent predictors of an early recovery of normal shoulder function were investigated using a separate prospective series of consecutive nonoperative displaced mid-shaft clavicular fractures recruited over a two-year period (aged ≥ 16 years). Patient demographics and functional recovery were assessed over the six months post-injury using a standardized protocol. Results: Data from the randomized controlled trial consisted of 86 patients who underwent operative fixation compared with 76 patients that united with nonoperative treatment. The recovery of normal shoulder function, as defined by a DASH score within the predicted 95% confidence interval for each respective patient, was similar between each group at six weeks (operative 26.7% vs nonoperative 25.0%, p = 0.800), three months (52.3% vs 44.2%, p = 0.768), and six months post-injury (86.0% vs 90.8%, p = 0.349). The mean DASH score and return to work were also comparable at each timepoint. In the prospective cohort, 86.5% (n = 173/200) achieved union by six months post-injury (follow-up rate 88.5%, n = 200/226). Regression analysis found that no specific patient, injury, or fracture predictor was associated with an early return of function at six or 12 weeks. Conclusion: Return of normal shoulder function was comparable between acute plate fixation and nonoperative management when union was achieved. One in two patients will have recovery of normal shoulder function at three months, increasing to nine out of ten patients at six months following injury when union occurs, irrespective of initial treatment

Meaningful values of the EQ-5D-3L in patients undergoing primary knee arthroplasty

AIMS: The aim of this study was to report the meaningful values of the EuroQol five-dimension three-level questionnaire (EQ-5D-3L) and EuroQol visual analogue scale (EQ-VAS) in patients undergoing primary knee arthroplasty (KA). METHODS: This is a retrospective study of patients undergoing primary KA for osteoarthritis in a university teaching hospital (Royal Infirmary of Edinburgh) (1 January 2013 to 31 December 2019). Pre- and postoperative (one-year) data were prospectively collected for 3,181 patients (median age 69.9 years (interquartile range (IQR) 64.2 to 76.1); females, n = 1,745 (54.9%); median BMI 30.1 kg/m(2) (IQR 26.6 to 34.2)). The reliability of the EQ-5D-3L was measured using Cronbach’s alpha. Responsiveness was determined by calculating the anchor-based minimal clinically important difference (MCID), the minimal important change (MIC) (cohort and individual), the patient-acceptable symptom state (PASS) predictive of satisfaction, and the minimal detectable change at 90% confidence intervals (MDC-90). RESULTS: The EQ-5D-3L demonstrated good internal consistency with an overall Cronbach alpha of 0.75 (preoperative) and 0.88 (postoperative), respectively. The MCID for the Index score was 0.085 (95% confidence interval (CI) 0.042 to 0.127) and EQ-VAS was 6.41 (95% CI 3.497 to 9.323). The MIC(COHORT) was 0.289 for the EQ-5D and 5.27 for the EQ-VAS. However, the MIC(INDIVIDUAL) for both the EQ-5D-3L Index (0.105) and EQ-VAS (-1) demonstrated poor-to-acceptable reliability. The MDC-90 was 0.023 for the EQ-5D-3L Index and 1.0 for the EQ-VAS. The PASS for the postoperative EQ-5D-3L Index and EQ-VAS scores predictive of patient satisfaction were 0.708 and 77.0, respectively. CONCLUSION: The meaningful values of the EQ-5D-3L Index and EQ-VAS scores can be used to measure clinically relevant changes in health-related quality of life in patients undergoing primary KA. Cite this article: Bone Joint Res 2022;11(9):619–628