234 research outputs found

    Energy Efficiency Improvements in Dry Drilling with Optimised Diamond-Like Carbon Coating

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    We demonstrate enhancements of performance and energy efficiency of cutting tools by deposition of diamond-like carbon (DLC) coatings on machine parts. DLC was deposited on steel drill bits, using plasma enhanced chemical vapour deposition (PECVD) with the acetylene precursor diluted with argon, to produce a surface with low friction and low wear rate. Drill bit performance in dry drilling of aluminium was quantified by analysis of power consumption and swarf flow. Optimised deposition conditions produced drill bits with greatly enhanced performance over uncoated drill bits, showing a 25% reduction in swarf clogging, a 36% reduction in power consumption and a greater than five-fold increase in lifetime. Surface analysis with scanning electron microscopy shows that DLC coated drills exhibit much lower aluminium build up on the trailing shank of the drill, enhancing the anti-adhering properties of the drill and reducing heat generation during operation, resulting in the observed improvements in efficiency. Variation of drilling efficiency with argon dilution of precursor is related to changes in the microstructure of the DLC coating

    Molecular typing of Rickettsia akari

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    Rickettsia akari, an obligately intracellular bacterium, is the causative agent of the cosmopolitan urban disease rickettsialpox. R. akari is an atypical representative of spotted fever group rickettsiae (SFG) as it is associated with rodent mites rather than ticks or fleas; however, only limited information is available about the degree of genetic variability found among isolates of R. akari. We examined 13 isolates of R. akari from humans, rodents and mites in the USA, the former Soviet Union, and the former Yugoslavia made between 1946 and 2003 for diversity in their tandem repeat regions (TR) and intergenic regions (IGR). The 1.23 Mb genome of R. akari strain Hartford CWPP was analyzed using Tandem Repeat Finder software (http://tandem.bu.edu) and 374 different TRs were identified, with size variation from 1 to 483 bp and with TR copy numbers ranging between 21 and 1.9, respectively. No size polymorphisms were detected among the 11 TR regions examined from 5 open reading frames and 6 IGR. Eighteen non-TR IGR’s were amplified and sequenced for the same isolates comprising a total of 5.995 bp (0.49%) of the Hartford CWPP strain chromosome. Three single nucleotide polymorphism (SNP) sites were detected in two IGR’s which permitted separation of the five R. akari isolates from Ukraine SSR from the other eight isolates. In conclusion, this is the first study reporting genetic heterogeneity among R. akari isolates of different geographic origins. Further exploration of this genetic diversity is needed to understand better the geographic distribution of R. akari and the epidemiology of rickettsialpox. The potential of mites as hosts for other rickettsial agents also needs further investigation

    The effect of time-to-surgery on outcome in elderly patients with proximal femoral fractures

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    <p>Abstract</p> <p>Background</p> <p>Whether reducing time-to-surgery for elderly patients suffering from hip fracture results in better outcomes remains subject to controversial debates.</p> <p>Methods</p> <p>As part of a prospective observational study conducted between January 2002 and September 2003 on hip-fracture patients from 268 acute-care hospitals all over Germany, we investigated the relationship of time-to-surgery with frequency of post-operative complications and one-year mortality in elderly patients (age ≥65) with isolated proximal femoral fracture (femoral neck fracture or pertrochanteric femoral fracture). Patients with short (≤12 h), medium (> 12 h to ≤36 h) and long (> 36 h) times-to-surgery, counting from the time of the fracture event, were compared for patient characteristics, operative procedures, post-operative complications and one-year mortality.</p> <p>Results</p> <p>Hospital data were available for 2916 hip-fracture patients (mean age (SD) in years: 82.1 (7.4), median age: 82; 79.7% women). Comparison of groups with short (n = 802), medium (n = 1191) and long (n = 923) time-to-surgery revealed statistically significant differences in a few patient characteristics (age, American Society of Anesthesiologists ratings classification and type of admission) and in operative procedures (total hip endoprosthesis, hemi-endoprosthetic implants, other osteosynthetic procedures). However, comparison of these same groups for frequency of postoperative complications revealed only some non-significant associations with certain complications such as post-operative bleeding requiring treatment (early surgery patients) and urinary tract infections (delayed surgery patients). Both unadjusted rates of one-year all-cause mortality (between 18.1% and 20.5%), and the multivariate-adjusted hazard ratios (HR for time-to-surgery: 1.04; p = 0.55) showed no association between mortality and time-to-surgery.</p> <p>Conclusion</p> <p>Although this study found a trend toward more frequent post-operative complications in the longest time-to-surgery group, there was no effect of time-to-surgery on mortality. Shorter time-to-surgery may be associated with somewhat lower rates of post-operative complications such as decubitus ulcers, urinary tract infections, thromboses, pneumonia and cardiovascular events, and with somewhat higher rates of others such as post-operative bleeding or implant complications.</p

    Intention to have the seasonal influenza vaccination during the COVID-19 pandemic among eligible adults in the UK: a cross-sectional survey

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    OBJECTIVE: To investigate the likelihood of having the seasonal influenza vaccination during the COVID-19 pandemic in individuals who were eligible to receive it. DESIGN: We conducted a cross-sectional online survey in July 2020. We included predictors informed by previous research, in the following categories: sociodemographic variables; uptake of influenza vaccine last winter and beliefs about vaccination. PARTICIPANTS: 570 participants (mean age: 53.07; 56.3% female, 87.0% white) who were eligible for the free seasonal influenza vaccination in the UK. RESULTS: 59.7% of our sample indicated they were likely to have the seasonal influenza vaccination, 22.1% reported being unlikely to have the vaccination and 18.2% were unsure. We used logistic regression to investigate variables associated with intention to receive a seasonal influenza vaccine in the 2020-2021 season. A positive attitude to vaccination in general predicted intention to have the influenza vaccine in 2020-2021 (OR 1.45, 95% CI 1.19 to 1.77, p<0.001) but the strongest predictor of intention was previous influenza vaccination behaviour (OR 278.58, 95% CI 78.04 to 994.46, p<0.001). CONCLUSIONS: Previous research suggests that increasing uptake of the influenza vaccination may help contain a COVID-19 outbreak, so steps need to be taken to convert intention into behaviour and to reach those individuals who reported being unlikely or unsure about having the vaccine

    Parents’ intention to vaccinate their child for COVID-19: a cross-sectional survey (CoVAccS – wave 3)

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    AbstractObjectivesTo investigate UK parents’ vaccination intention at a time when COVID-19 vaccination was available to some children.Study designData reported are from the second wave of a prospective cohort study.MethodsOnline survey of 270 UK parents (conducted 4-15 October 2021). At this time, vaccination was available to 16- and 17-year-olds and had become available to 12- to 15- year-olds two weeks prior. We asked participants whose child had not yet been vaccinated how likely they were to vaccinate their child for COVID-19. Linear regression analyses were used to investigate factors associated with intention. Parents were also asked for their main reasons behind vaccination intention. Open-ended responses were analysed using content analysis.ResultsParental vaccination intention was mixed (likely: 39.3%, 95% CI 32.8%, 45.7%; uncertain: 33.9%, 27.7%, 40.2%; unlikely: 26.8%, 20.9%, 32.6%). Intention was associated with: parental COVID-19 vaccination status; greater perceived necessity and social norms regarding COVID-19 vaccination; greater COVID-19 threat appraisal; and lower vaccine safety and novelty concerns. In those who intended to vaccinate their child, the main reasons for doing so were to protect the child and others. In those who did not intend to vaccinate their child, the main reason was safety concerns.ConclusionsParent COVID-19 vaccination and psychological factors explained a large percentage of the variance in vaccination intention for one’s child. How fluctuating infection rates, more children being vaccinated, and the UK’s reliance on vaccination as a strategy to live with COVID-19 may impact parents’ intention to vaccinate their child requires further study.</jats:sec

    Targeting macrophage Histone deacetylase 3 stabilizes atherosclerotic lesions

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    Macrophages are key immune cells found in atherosclerotic plaques and critically shape atherosclerotic disease development. Targeting the functional repertoire of macrophages may hold novel approaches for future atherosclerosis management. Here, we describe a previously unrecognized role of the epigenomic enzyme Histone deacetylase 3 (Hdac3) in regulating the atherosclerotic phenotype of macrophages. Using conditional knockout mice, we found that myeloid Hdac3 deficiency promotes collagen deposition in atherosclerotic lesions and thus induces a stable plaque phenotype. Also, macrophages presented a switch to anti-inflammatory wound healing characteristics and showed improved lipid handling. The pro-fibrotic phenotype was directly linked to epigenetic regulation of the Tgfb1 locus upon Hdac3 deletion, driving smooth muscle cells to increased collagen production. Moreover, in humans, HDAC3 was the sole Hdac upregulated in ruptured atherosclerotic lesions, Hdac3 associated with inflammatory macrophages, and HDAC3 expression inversely correlated with pro-fibrotic TGFB1 expression. Collectively, we show that targeting the macrophage epigenome can improve atherosclerosis outcome and we identify Hdac3 as a potential novel therapeutic target in cardiovascular disease

    Genome-Wide Functional Divergence after the Symbiosis of Proteobacteria with Insects Unraveled through a Novel Computational Approach

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    Symbiosis has been among the most important evolutionary steps to generate biological complexity. The establishment of symbiosis required an intimate metabolic link between biological systems with different complexity levels. The strict endo-cellular symbiotic bacteria of insects are beautiful examples of the metabolic coupling between organisms belonging to different kingdoms, a eukaryote and a prokaryote. The host (eukaryote) provides the endosymbiont (prokaryote) with a stable cellular environment while the endosymbiont supplements the host's diet with essential metabolites. For such communication to take place, endosymbionts' genomes have suffered dramatic modifications and reconfigurations of proteins' functions. Two of the main modifications, loss of genes redundant for endosymbiotic bacteria or the host and bacterial genome streamlining, have been extensively studied. However, no studies have accounted for possible functional shifts in the endosymbiotic proteomes. Here, we develop a simple method to screen genomes for evidence of functional divergence between two species clusters, and we apply it to identify functional shifts in the endosymbiotic proteomes. Despite the strong effects of genetic drift in the endosymbiotic systems, we unexpectedly identified genes to be under stronger selective constraints in endosymbionts of aphids and ants than in their free-living bacterial relatives. These genes are directly involved in supplementing the host's diet with essential metabolites. A test of functional divergence supports a strong relationship between the endosymbiosis and the functional shifts of proteins involved in the metabolic communication with the insect host. The correlation between functional divergence in the endosymbiotic bacterium and the ecological requirements of the host uncovers their intimate biochemical and metabolic communication and provides insights on the role of symbiosis in generating species diversity

    Patients with femoral or distal forearm fracture in Germany: a prospective observational study on health care situation and outcome

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    BACKGROUND: Distal radius and proximal femoral fractures are typical injuries in later life, predominantly due to simple falls, but modulated by other relevant factors such as osteoporosis. Fracture incidence rates rise with age. Because of the growing proportion of elderly people in Western industrialized societies, the number of these fractures can be expected to increase further in the coming years, and with it the burden on healthcare resources. Our study therefore assessed the effects of these injuries on the health status of older people over time. The purpose of this paper is to describe the study method, clinical parameters of fracture patients during hospitalization, mortality up to one and a half years after discharge in relation to various factors such as type of fracture, and to describe changes in mobility and living situation. METHODS: Data were collected from all consecutive patients (no age limit) admitted to 423 hospitals throughout Germany with distal radius or femoral fractures (57% acute-care, femoral and forearm fractures; 43% rehabilitation, femoral fractures only) between January 2002 and September 2003. Polytrauma and coma patients were excluded. Demographic characteristics, exact fracture location, mobility and living situation, clinical and laboratory parameters were examined. Current health status was assessed in telephone interviews conducted on average 6–7 months after discharge. Where telephone contact could not be established, at least survival status (living/deceased/date of death) was determined. RESULTS: The study population consisted of 12,520 femoral fracture patients (86.8% hip fractures), average age 77.5 years, 76.5% female, and 2,031 forearm fracture patients, average age 67.6 years, 81.6% female. Women's average age was 6.6 (femoral fracture) to 10 years (forearm fracture) older than men's (p < 0.0001). Only 4.6% of femoral fracture patients experienced changes in their living situation post-discharge (53% because of the fracture event), although less than half of subjects who were able to walk without assistive devices prior to the fracture event (76.7%) could still do so at time of interview (34.9%). At time of interview, 1.5% of subjects were bed-ridden (0.2% before fracture). Forearm fracture patients reported no change in living situation at all. Of the femoral fracture patients 119 (0.95%), and of the forearm fracture patients 3 (0.15%) died during hospital stay. Post-discharge (follow-up one and a half years) 1,463 femoral fracture patients died (19.2% acute-care patients, 8.5% rehabilitation patients), but only 60 forearm fracture patients (3.0%). Ninety percent of femoral fracture deaths happened within the first year, approximately 66% within the first 6 months. More acute-care patients with a pertrochanteric fracture died within one year post-discharge (20.6%) than patients with a cervical fracture (16.1%). CONCLUSION: Mortality after proximal femoral fracture is still alarmingly high and highest after pertrochanteric fracture. Although at time of interview more than half of femoral fracture patients reported reduced mobility, most patients (96%) attempt to live at home. Since forearm fracture patients were on average 10 years younger than femoral fracture patients, forearm fractures may be a means of diagnosing an increased risk of later hip fractures
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