695915 research outputs found
Sort by
Trends in the level of evidence and impact of clinical studies published in leading oral implantology journals: 2008-2018
No full textObjectives: To present the characteristics and level of evidence (LOE) of clinical studies published in leading oral implantology journals during 2008-2018, and to explore whether the LOE of a study is associated with its scientific and social impact.Materials and methods: Clinical studies with direct relevance to the evaluation of healthcare interventions published in 2008, 2013 and 2018 in six oral implantology journals were identified via hand searches. A modified 4-level Oxford 2011 LOE tool was used to assess the LOE of all eligible studies. The citation count and Altmetric Attention Score (AAS) of each study was extracted from Web of Science and Altmetric Explorer, respectively. Thereafter, multivariable generalized estimation equation analyses were used to investigate the association between LOE, citation counts and AAS, adjusting for potential confounding factors and clustering effects.Results: A total of 763 clinical studies were included, among which the proportion of level-1, level-2, level-3 and level-4 studies was 2.4%, 30.4%, 40.2% and 27.0%, respectively. During 2008-2018, the proportion of high LOE studies (level-1 and level-2) increased substantially from 24.6% to 43.1%, although the number of systematic reviews that only include randomized controlled trials has remained limited. According to multivariable analyses, the citation count (p=0.002) and AAS (p=0.005) of high LOE studies were both significantly greater than those of low LOE studies.Conclusions: During the past decade, the proportion of high LOE studies has increased substantially in the field of oral implantology. Clinical studies with higher LOE tend to have greater scientific and social impact
Effect of Waiting Time on Concentration of Chemical Markers measured on Laboratory Ageing Samples
No full textLaboratory scale thermal ageing experiments have been used not only to study the degradation of the insulation materials but also to understand the variation of chemical markers in liquid during the ageing process. However, trends obtained from different experiments often disagree with each other due to experimental variations such as material type, material ratio and ageing temperature. In addition to these well-known factors, there are lesser- known factors such as the duration for which samples are left at room temperature after an ageing experiment, which could affect the concentration of chemical markers in liquid. It is known that temperature could affect the partitioning of chemical markers among the liquid, solid and gas phase. Hence the concentration of certain chemical-markers in liquid could vary depending on the duration for which samples are left at room temperature prior to the sampling of oil for the measurements. This paper investigates the effect of this sampling period on the variation of chemical markers including water, methanol and ethanol in liquid after a laboratory scale ageing experiment conducted at 150 °C. Results showed that the concentration of the investigated chemical markers in liquid decrease continuously when the sample is left at room temperature, with water having the highest reduction followed by methanol and ethanol
Rotational atherectomy and same day discharge: safety and growth from a national perspective
No full textObjectives We explore whether same day discharge (SDD) is a feasible and safe practice following rotational atherectomy (ROTA) treatment during elective percutaneous coronary intervention (PCI), and examine which baseline characteristics are independently associated with SDD. Background SDD following elective ROTA PCI is not recommended as per the recent SCAI consensus. However, reports show it is practiced and no previous study has evaluated its safety and feasibility. Methods Our dataset included 4,591 patients undergoing elective ROTA PCI in England & Wales within an 8-years period. Independent associations with SDD were quantified via a multiple logistic regression model and the BCIS 30-day mortality risk model was used to evaluate the safety of SDD. Results The majority of elective ROTA PCI cases remain at the hospital for overnight (ON) observation, although SDD rates increased substantially from 6.7% in 2007 to 35.5% in 2014. The use of glycoprotein IIb/IIIa antagonists, Q wave AMI, left main PCI and valvular heart disease were independently associated with ON, while patients operated underwent transradial PCI were more likely to be SDD (OR=1.77, 95% CI [1.45-2.15]). Over the study period, observed mortality rates were not significantly higher than those expected from the BCIS risk model. Conclusions Our findings did not show superiority of the ON strategy over SDD for higher risk cases undergoing elective ROTA PCI, in terms of 30-day mortality. This is the first study to examine the safety of SDD after elective ROTA PCI and more should follow
Online Consultation and Emergency Management in Paediatric Dentistry During the COVID-19 Pandemic in Wuhan: A Retrospective Study
No full textBackground: The COVID-19 pandemic posed a great challenge to paediatric dentistry, which confronted with the restriction of service and resource shortage.Aim: To retrospectively analyse the information of children’s dental online healthconsultation during the COVID-19 pandemic in China, and to provide methods to distinguish between dental emergencies and non-emergencies as well as theirmanagement.Design: We collected all the online consultation information in Dept. of Paediatricdentistry, XXXXX from February 2 to March 31, 2020, and extracted the information of age, gender, reason for consultation, description of symptom and preliminary diagnosis of the children.Results: A total of 474 online consultations of paediatric dentistry were included within 59 days during lockdown, and 190 (40.1%) were dental emergencies and 284 (59.9%) non-emergencies. Of 190 emergency consultations, 186 (97.9%) showed swelling, pain, trauma with or without systemic symptoms. Among 284 non-emergency consultations, retained primary teeth (n=126) and orthodontic consultation (n=53) were the most common reasons for consultation.Conclusion: The paediatric emergency and non-emergency problems should be clearly distinguished and sufficient instructions provided in the special period of COVID-19. Priorities also should be set to deal with urgent conditions after the release of lockdown
The impact of COVID-19 on percutaneous coronary intervention for ST-elevation myocardial infarction
No full textBackground: The objective of the study was to identify any changes in primary PCI for ST-elevation myocardial infarction (STEMI) in England by analyzing procedural numbers, clinical characteristics and patient outcomes during the COVID-19 pandemic. Methods: We conducted a retrospective cohort study of patients who underwent PCI in England between January 2017 and April 2020 in the British Cardiovascular Intervention Society (BCIS)-National Institute of Cardiovascular Outcomes Research (NICOR) database. Analysis was restricted to forty-four hospitals that reported contemporaneous activity on PCI. Only patients with primary PCI for STEMI were included in the analysis. Results: A total of 34,127 patients with STEMI (primary PCI 33,938, facilitated PCI 108, rescue PCI 81) were included in the study. There was a decline in the number of procedures by 43% (n=497) in April 2020 compared to the average monthly procedures between 2017 and 2019 (n=865). For all patients, the median time from symptom-to-hospital showed increased after the lockdown (150[99-270] vs 135[89-250] min, p=0.004) and a longer door-to-balloon time after the lockdown (48[21-112] vs 37[16-94] min, p<0.001). The in-hospital mortality rate was 4.8% before the lockdown and 3.5% after the lockdown (p=0.12). Following adjustment for baseline characteristics, no differences were observed for in-hospital death (OR 0.87 95%CI 0.45-1.68, p=0.67) and MACE (OR 0.71 95%CI 0.39-1.32, p=0.28). Conclusions: Following the lockdown in England, we observed a decline in primary PCI procedures for STEMI and increases in overall symptom-to-hospital and door-to-balloon time for patients with STEMI. Restructuring health services during COVID-19 has not adversely influenced in-hospital outcomes
Prostate cancer risk by BRCA2 genomic regions
No full textA BRCA2 prostate cancer cluster region (PCCR) was recently proposed (c.7914 to 3’) wherein pathogenic variants (PVs) are associated with higher prostate cancer (PCa) risk than PVs elsewhere in the BRCA2 gene. Using a prospective cohort study of 447 male BRCA2 PV carriers recruited in the UK and Ireland from 1998 to 2016, we estimated standardised incidence ratios (SIRs) compared to population incidences and assessed variation in risk by PV location. Carriers of PVs in the PCCR had a PCa SIR of 8.33 (95% confidence interval [CI] 4.46-15.58) and were at higher risk of PCa than carriers of other BRCA2 PVs (SIR=3.31, 95% CI 1.97-5.57; hazard ratio [HR]=2.34, 95% CI 1.09-5.03). PCCR PV carriers had an estimated cumulative PCa risk of 44% (95% CI 23%-72%) by age 75 and 78% (95% CI 54%-94%) by age 85. Our results corroborate the existence of a PCCR in BRCA2 in a prospective cohort
Comparison between Coreless and Yokeless Stator Designs in Fully-Superconducting Propulsion Motors
No full textHybrid electric propulsion could be the solution to the ambitious environmental targets of the aerospace industry. Fully-superconducting machines have the potential to deliver the step-change in specific torque, power and efficiency capabilities required for large civil transport aircraft applications. However fully-superconducting machines are still in their infancy. This paper investigates the electromagnetic design of two different stator design concepts for an AC fully-superconducting machine for an aerospace distributed fan motor application. A benchmark aerospace specification of 1 MW was chosen and the design of a conventional permanent-magnet machine was used to assess the performance of the two equivalent fully-superconducting AC motor designs. Following the guidelines from an experimental study of the losses in a small AC stator prototype with MgB _2 coils, a fully-superconducting air-cored stator design and a new yokeless stator design are proposed. Both AC superconducting machine designs use superconducting bulk magnets mounted on a rotor core and an MgB _2 superconducting stator winding. This paper discusses the key design issues of the two stator layouts in relation to the current aerospace targets for efficiency and power density
The Role of Uncertainty as a Facilitator to Reflection in Self-Tracking
No full textSelf-trackers reflect on their personal data to understand their behaviour and plan accordingly. Often, this reflection involves uncertainty, which can affect decision-making. To better understand the role of uncertainty, we conducted an interview study to comprehend how uncertainty influences reflection and the resulting actions. Our findings suggest that, in addition to the conventional role of uncertainty as a barrier, uncertainty also manifests as a trigger and facilitator to reflection. We discuss functionalities to alleviate the negative effects of uncertainty (e.g. incorporating users’ expectations in self-tracking), and leverage its positive effects through activity reconstruction mechanisms
Sn 5s 2 lone pairs and the electronic structure of tin sulphides: a photoreflectance, high-energy photoemission and theoretical investigation
No full textThe effects of Sn 5s lone pairs in the different phases of Sn sulphides are investigated with photoreflectance, hard x-ray photoemission spectroscopy (HAXPES) and density functional theory. Due to the photon energy-dependence of the photoionisation cross-sections, at high photon energy, the Sn 5s orbital photoemission has increased intensity relative to that from other orbitals. This enables the Sn 5s state contribution at the top of the valence band in the different Sn-sulphides, SnS, Sn2S3, and SnS2, to be clearly identified. SnS and Sn2S3 contain Sn(II) cations and the corresponding Sn 5s lone pairs are at the valence band maximum (VBM), leading to ∼1.0–1.3 eV band gaps and relatively high VBM on an absolute energy scale. In contrast, SnS2 only contains Sn(IV) cations, no filled lone pairs and therefore has a ∼2.3 eV room temperature band gap and much lower VBM compared with SnS and Sn2S3. The direct band gaps of these materials at 20 K are found using photoreflectance to be 1.36, 1.08 and 2.47 eV for SnS, Sn2S3 and SnS2, respectively, which further highlights the effect of having the lone pair states at the VBM. As well as elucidating the role of the Sn 5s lone pairs in determining the band gaps and band alignments of the family of Sn-sulphide compounds, this also highlights how HAXPES is an ideal method for probing the lone pair contribution to the density of states of the emerging class of materials with ns2 configuration