Properties of Polyetheretherketone (PEEK) transferred materials in a PEEK-steel contact

Polyetheretherketone (PEEK) is a high performance polymer that can be an alternative to metal for some moving components in unlubricated conditions. During rubbing, PEEK is transferred to the counterface. The formation and properties of PEEK transfer films on steel and sapphire are studied by in-situ observations of PEEK wear process, contact temperatures and triboemission, as well as FTIR and Raman spectroscopies ex-situ. Our results suggest that frictional heating alone may not be sufficient to generate PEEK degradation observed in the transfer materials. Triboplasma observed during rubbing, together with mechanical shear, may promote generations of radicals and degradation of PEEK, which subsequently influence the properties of PEEK transfer film and performance of polymer-metal tribopair.This work is partly funded by EPSRC (Grant number: EP/L023202/1)

Using acoustic emission to characterize friction and wear in dry sliding steel contacts

Acoustic emission (AE) was recorded during tribological tests on 52,100 steel specimens under different loads. AE signals were transformed to the frequency domain using a Fast Fourier Transform and parameters such as power, RMS amplitude, mean frequency, and energy were analyzed and compared with friction coefficient and wear volume measurements. Results show that certain acoustic frequencies reflect friction while others reflect wear. If frequencies are chosen optimally, AE and friction signals are highly correlated (Pearson coefficients >0.8). SEM and Raman analysis reveal how plastic deformation and oxide formation affect friction, wear and AE simultaneously. AE recordings contains more information than conventional friction and wear volume measurements and are more sensitive to changes in mechanism. This all demonstrates AE's potential as a tool to monitor tribological behavior.This work was supported by the Overseas Study Program of Jiangsu Higher Education Institutions; the Natural Science Foundation of Jiangsu Province, China (Grant no. BK20160353); the Natural Science Foundation of Jiangsu Higher Education Institutions (Grant no. 16KJB460032); the Key Laboratory of Suzhou (SZS201815); the Top-notch Academic Programs Project of Jiangsu Higher Education Institutions (TAPP) (Grant no. PPZY2015B186) and the Scientific Research Foundation of SIIT (Grant no. 2017kyqd015)

Exploiting air cushion effects to optimise a superhydrophobic/hydrophilic patterned liquid ring sealed air bearing

© 2019 Elsevier Ltd A thrust bearing consisting of an air cushion formed within a liquid ring has been developed, which takes advantage of the Laplace pressure induced by the liquid/air surface tension. As forces induced by Laplace pressure and surface tension scales down much more slowly than gravity and inertial forces, such a bearing has great potential when scaled down to the micro-scale. The liquid ring between the rotor and the stator of the bearing is anchored there by alternating hydrophilic and superhydrophobic patterns. An important discovery is that the performance of this bearing is greatly enhanced by the sealed cushion of air within the ring. This air cushion and thin liquid ring arrangement mean that the solid/solid contact of the bearing is replaced by solid/air and solid/liquid contact which significantly reduces the friction and wear. The factors which affects the performance of the bearing have been studied both experimentally and numerically providing results that can be used to optimise the design of this new type of bearing.The project was funded by the CSC Imperial Scholarship (Grant no. 201700260048). The authors also acknowledge the support received by the Engineering and Physical Sciences Research Council via Professor Dini's Established Career Fellowship, EP/N025954/1

Interventions to improve children's access to mental health care: a systematic review and meta-analysis

AimsMental disorders in children are a significant and growing cause of morbidity worldwide. Although interventions to help overcome barriers along the pathway to accessing health care for children with mental disorders exist, there is no overview of randomised controlled trials (RCTs) on these interventions as yet. This study aimed to systematically identify RCTs of interventions to improve access to mental health care for children and synthesise them using a conceptual framework of access to health care.MethodsThis systematic review was performed following a predefined protocol registered with PROSPERO (ID: CRD42018081714). We searched the databases MEDLINE, EMBASE, PsycINFO and CENTRAL for RCTs up to 15 May 2019 using terms related to the concepts ‘young people,’ ‘mental disorders’ and ‘help-seeking interventions’ and scanned reference lists from relevant studies. Two reviewers independently screened all identified articles in a two-stage process, extracted results on outcomes of interest (knowledge, attitudes, intentions, help-seeking, accessing care, mental health outcomes and satisfaction), assessed the risk of bias and conducted meta-analyses where deemed appropriate.ResultsAfter screening 5641 identified articles, 34 RCTs were eligible for inclusion. Eighty per cent of universal school-based interventions measuring knowledge (n = 5) and 67% measuring attitudes (n = 6) reported significantly better results compared with controls on those outcomes, whereas 20% measuring access to care (n = 5) and none measuring mental health outcomes (n = 7) did. In contrast, 71% of interventions targeting at-risk individuals (n = 21) reported better access to care compared with controls, while just 33% (n = 6) did for mental health outcomes. For satisfaction with care, this proportion was 80% (n = 5). Meta-analyses of interventions measuring initial appointment attendance yielded combined odds ratios of 3.11 (2.07–4.67) for appointment reminder interventions and 3.51 (2.02–6.11) for treatment engagement interventions. The outcomes for universal school-based interventions were heterogeneous and could not be summarised quantitatively through meta-analysis.ConclusionsTo have a population-level effect on improving children's access to mental health care, two-stage interventions that identify those in need and then engage them in the health-care system may be necessary. We need more evidence on interventions to target contextual factors such as affordability and infrastructural barriers.</jats:sec

Medication incidents in primary care medicine: protocol of a study by the Swiss Federal Sentinel Reporting System.

BACKGROUND/RATIONALE: Patient safety is a major concern in healthcare systems worldwide. Although most safety research has been conducted in the inpatient setting, evidence indicates that medical errors and adverse events are a threat to patients in the primary care setting as well. Since information about the frequency and outcomes of safety incidents in primary care is required, the goals of this study are to describe the type, frequency, seasonal and regional distribution of medication incidents in primary care in Switzerland and to elucidate possible risk factors for medication incidents. Label="METHODS AND ANALYSIS" ="METHODS"/&gt; &lt;AbstractText STUDY DESIGN AND SETTING: We will conduct a prospective surveillance study to identify cases of medication incidents among primary care patients in Switzerland over the course of the year 2015. PARTICIPANTS: Patients undergoing drug treatment by 167 general practitioners or paediatricians reporting to the Swiss Federal Sentinel Reporting System. INCLUSION CRITERIA: Any erroneous event, as defined by the physician, related to the medication process and interfering with normal treatment course. EXCLUSION CRITERIA: Lack of treatment effect, adverse drug reactions or drug-drug or drug-disease interactions without detectable treatment error. PRIMARY OUTCOME: Medication incidents. RISK FACTORS: Age, gender, polymedication, morbidity, care dependency, hospitalisation. STATISTICAL ANALYSIS: Descriptive statistics to assess type, frequency, seasonal and regional distribution of medication incidents and logistic regression to assess their association with potential risk factors. Estimated sample size: 500 medication incidents. LIMITATIONS: We will take into account under-reporting and selective reporting among others as potential sources of bias or imprecision when interpreting the results. ETHICS AND DISSEMINATION: No formal request was necessary because of fully anonymised data. The results will be published in a peer-reviewed journal. TRIAL REGISTRATION NUMBER: NCT0229537

Mapping the landscape of lung cancer breath analysis: A scoping review (ELCABA)

Lung cancer is the leading cause of cancer death worldwide due to its late-stage detection. Lung cancer screening, including low-dose computed tomography (low-dose CT), provides an initial clinical solution. Nevertheless, further innovations and refinements would help to alleviate remaining limitations. The non-invasive, gentle, and fast nature of breath analysis (BA) makes this technology highly attractive to supplement low-dose CT for an improved screening algorithm. However, BA has not taken hold in everyday clinical practice. One reason might be the heterogeneity and variety of BA methods. This scoping review is a comprehensive summary of study designs, breath analytical methods, and suggested biomarkers in lung cancer. Furthermore, this synthesis provides a framework with core outcomes for future studies in lung cancer BA. This work supports future research for evidence synthesis, meta-analysis, and translation into clinical routine workflows. Keywords: Biomarker; Breath; Detection; Lung cancer; Scoping review; Screenin

Transient aspects of plasma luminescence induced by triboelectrification of polymers

Transient electric gas discharges that occur around sliding interfaces during contact electrification of polymers were studied at millisecond timescales and with micrometre resolution. Deduced vibrational temperatures indicate cold plasma resulting from positive corona discharge. At millisecond timescales, previously unseen rapid discharge events are observed, and modelling suggests that these result from streamer development, triggered by electron emission from the polymer surface. Those which occur over a period of several seconds are shown to be caused by competition between charge generation and the formation of polymer films. The findings explain the interplay between charging and plasma generation and their dependence on wear processes.UK Engineering and Physical Sciences Research Council (EP/J002100/1), Additional equipment funding provided by the Taiho Kogyo Tribology Research Foundation (11A01). Spanish Ministry of Economy, Industry and Competitivity through the grant BIA2016-79582-

Comparative adverse effects, perceptions and attitudes related to BNT162b2, mRNA1273, or JNJ-78436735 SARS-CoV-2 vaccines: A population-based longitudinal cohort

Importance Long-term control of SARS-CoV-2 requires effective vaccination strategies. This has been challenged by public mistrust and spread of misinformation regarding vaccine safety. Hence, better understanding and communication on the longer-term and comparative experiences of general population individuals following SARS-CoV-2 vaccination are required. Objective To evaluate and compare self-reported adverse effects following SARS-CoV-2 vaccination, participants’ perceptions regarding vaccinations and their compliance with recommended public health measures. Design, Setting and Participants Population-based longitudinal cohort of 575 adults, randomly selected from all individuals presenting to the reference vaccination center of the Canton of Zurich, Switzerland, for receipt of BNT162b2, mRNA1273, or JNJ-78436735