The influence of clearance on friction, lubrication and squeaking in large diameter metal-on-metal hip replacements

Large diameter metal-on-metal bearings (MOM) are becoming increasingly popular, addressing the needs of young and more active patients. Clinical data has shown excellent short-to-mid-term results, though incidences of transient squeaking have been noted between implantation and up to 2 years post-operative. Geometric design features, such as clearance, have been significant in influencing the performance of the bearings. Sets of MOM bearings with different clearances were investigated in this study using a hip friction simulator to examine the influence of clearance on friction, lubrication and squeaking. The friction factor was found to be highest in the largest clearance bearings under all test conditions. The incidence of squeaking was also highest in the large clearance bearings, with all bearings in this group squeaking throughout the study. A very low incidence of squeaking was observed in the other two clearance groups. The measured lubricating film was found to be lowest in the large clearance bearings. This study suggests that increasing the bearing clearance results in reduced lubricant film thickness, increased friction and an increased incidence of squeaking

Strong Casimir force reduction through metallic surface nanostructuring

The Casimir force between bodies in vacuum can be understood as arising from their interaction with an infinite number of fluctuating electromagnetic quantum vacuum modes, resulting in a complex dependence on the shape and material of the interacting objects. Becoming dominant at small separations, the force plays a significant role in nanomechanics and object manipulation at the nanoscale, leading to a considerable interest in identifying structures where the Casimir interaction behaves significantly different from the well-known attractive force between parallel plates. Here we experimentally demonstrate that by nanostructuring one of the interacting metal surfaces at scales below the plasma wavelength, an unexpected regime in the Casimir force can be observed. Replacing a flat surface with a deep metallic lamellar grating with sub-100 nm features strongly suppresses the Casimir force and for large inter-surfaces separations reduces it beyond what would be expected by any existing theoretical prediction.Comment: 11 pages, 8 figure

Understanding the diagnosis and management of multisystem inflammatory syndrome in adults (MIS-A) in the UK: results of a national Delphi process

Infection with SARS-CoV-2 may trigger a delayed hyper-inflammatory illness in children called paediatric multisystem inflammatory syndrome temporally associated with COVID-19 (PIMS-TS). A similar syndrome is increasingly recognised in adults termed multisystem inflammatory syndrome in adults (MIS-A) and may present acutely to medical or surgical specialties with severe symptoms, such as acute abdominal pain or cardiogenic shock. No national guidelines exist in the UK for the management of MIS-A and there is limited evidence to guide treatment plans. We undertook a national Delphi process to elicit opinions from experts in hyperinflammation about the diagnosis and management of MIS-A with the dual aim of improving recognition and producing a management guideline. Colleagues in paediatrics successfully initiated a national consensus management document that facilitated regional multidisciplinary referral and follow-up pathways for children with PIMS-TS, and we propose a similar system be developed for adult patients across the UK. This would facilitate better recognition and treatment of MIS-A across the multiple specialties to which it may present as well as enable follow-up with specialty services post-discharge

On the way to specifically targeting minimal residual disease?

The target of all adjuvant systemic therapies after surgery in breast cancer is the eradication of a minimal subclinical residual disease. Although it is well known that tumor cell dissemination takes place already at an early stage of the disease, little is known about the tumorbiological parameters of these residual cells. Selection of patients eligible for adjuvant endocrine therapies is based on the analysis of receptor expression in the primary tumor – although the analysis is directed against disseminated tumor cells, these cells may vary in receptor expression in comparison with the primary tumor

SSI-AWARE: Self-Sovereign Identity Authenticated backup With Auditing by Remote Entities

Part 5: CybersecurityInternational audienceThe self-sovereign identity (SSI) model entails the full responsibility and sovereignty of a user regarding his identity data. This identity data can contain private data which is solely known to the user. The user himself is therefore required to manage the whole lifecycle of his private data, including the backup and restore. We show that prior work on how to backup and restore the user’s identity data does not meet the requirements of the SSI setting, and we present the first solution which does meet the requirements. Authenticated backup with auditing by remote entities (AWARE) combines SSI sustaining aspects and extends them to create a truly self-sovereign backup-and-restore protocol. In AWARE, trusted, physically met humans, called custodians, hold a secure device. Custodians with a secure device offer an offline backup possibility and a secure channel. The backup and restore are audited by commits on a publicly accessible distributed ledger. These commits are answered by auditing services which are required during restore. Only some auditing services hold relevant data for a restore. The self sovereignty of the user lies in the exclusive information which auditing services hold relevant data. AWARE  is the first backup-and-restore mechanism that fully complies with the SSI model. We perform an in-depth security-risk analysis of AWARE, showing a risk rating which is comparable to the best risk rating o related non-SSI-compliant backup-and-restore mechanisms. We instantiate the AWARE protocol with cryptographic primitives providing a high security level of 256-bit. We show its implementation feasibility by providing a simulation of AWARE, and conclude with an estimated performance analysis on a microcontoller architecture based on our simulation and implementation results in the literature

International Veterinary Epilepsy Task Force Consensus Proposal: Diagnostic approach to epilepsy in dogs

This article outlines the consensus proposal on diagnosis of epilepsy in dogs by the International Veterinary Epilepsy Task Force. The aim of this consensus proposal is to improve consistency in the diagnosis of epilepsy in the clinical and research settings. The diagnostic approach to the patient presenting with a history of suspected epileptic seizures incorporates two fundamental steps: to establish if the events the animal is demonstrating truly represent epileptic seizures and if so, to identify their underlying cause. Differentiation of epileptic seizures from other non-epileptic episodic paroxysmal events can be challenging. Criteria that can be used to make this differentiation are presented in detail and discussed. Criteria for the diagnosis of idiopathic epilepsy (IE) are described in a three-tier system. Tier I confidence level for the diagnosis of IE is based on a history of two or more unprovoked epileptic seizures occurring at least 24 h apart, age at epileptic seizure onset of between six months and six years, unremarkable inter-ictal physical and neurological examination, and no significant abnormalities on minimum data base blood tests and urinalysis. Tier II confidence level for the diagnosis of IE is based on the factors listed in tier I and unremarkable fasting and post-prandial bile acids, magnetic resonance imaging (MRI) of the brain (based on an epilepsy-specific brain MRI protocol) and cerebrospinal fluid (CSF) analysis. Tier III confidence level for the diagnosis of IE is based on the factors listed in tier I and II and identification of electroencephalographic abnormalities characteristic for seizure disorders. The authors recommend performing MRI of the brain and routine CSF analysis, after exclusion of reactive seizures, in dogs with age at epileptic seizure onset 6 years, inter-ictal neurological abnormalities consistent with intracranial neurolocalisation, status epilepticus or cluster seizure at epileptic seizure onset, or a previous presumptive diagnosis of IE and drug-resistance with a single antiepileptic drug titrated to the highest tolerable dose

The impact of loco-regional recurrences on metastatic progression in early-stage breast cancer: a multistate model

To study whether the effects of prognostic factors associated with the occurrence of distant metastases (DM) at primary diagnosis change after the incidence of loco-regional recurrences (LRR) among women treated for invasive stage I or II breast cancer. The study population consisted of 3,601 women, enrolled in EORTC trials 10801, 10854, or 10902 treated for early-stage breast cancer. Data were analysed in a multivariate, multistate model by using multivariate Cox regression models, including a state-dependent covariate. The presence of a LRR in itself is a significant prognostic risk factor (HR: 3.64; 95%-CI: 2.02-6.5) for the occurrence of DM. Main prognostic risk factors for a DM are young age at diagnosis (</=40: HR: 1.79; 95%-CI: 1.28-2.51), larger tumour size (HR: 1.58; 95%-CI: 1.35-1.84) and node positivity (HR: 2.00; 95%-CI: 1.74-2.30). Adjuvant chemotherapy is protective for a DM (HR: 0.66; 95%-CI: 0.55-0.80). After the occurrence of a LRR the latter protective effect has disappeared (P = 0.009). The presence of LRR in itself is a significant risk factor for DM. For patients who are at risk of developing LRR, effective local control should be the main target of therapy