Nonlinear Correction to the Euler Buckling Formula for\ud Compressible Cylinders

Euler’s celebrated buckling formula gives the critical load N for the buckling of a slender cylindrical column with radius B and length L as\ud \ud N/(π 3B2)=(E/4)(B/L)2,\ud \ud where E is Young’s modulus. Its derivation relies on the assumptions that linear elasticity applies to this problem, and that the slenderness (B/L) is an infinitesimal quantity. Here we ask the following question: What is the first nonlinear correction in the right hand-side of this equation when terms up to (B/L)4 are kept? To answer this question, we specialize the exact solution of non-linear elasticity for the homogeneous compression of a thick cylinder with lubricated ends to the theory of third-order elasticity. In particular, we highlight the way second- and third-order constants —including Poisson’s ratio— all appear in the coefficient of (B/L)4

Resting EEG asymmetry markers of multiple facets of the behavioral approach system: a LORETA analysis

Previously published models of frontal activity linked high relative left frontal activity to the behavioral approach system (BAS) and impulsivity. Additionally, these models did not account for BAS facets encompassing the anticipation of reward, i.e., goal-driven persistence (BAS–GDP) and reward interest (BAS–RI), from those that deal with the actual hedonic experience of reward, i.e., reward reactivity (BAS–RR) and impulsivity (BAS–I). Using resting electroencephalographic (EEG) recordings, the source localization (LORETA) method allowed us to calculate the hemispheric asymmetry of the current density within the alpha band (7.5–13 Hz) in ten regions of interest. Compared to low BAS subtrait scorers, high BAS subtrait scorers (except for BAS–I) were correlated with greater relative left-sided activity in the superior frontal gyrus (BA10). Further, an isolated effective coherence (iCOH) analysis of the beta activity (21 Hz) disclosed that high impulsive scorers as compared to low impulsive ones had higher connectivity between the superior frontal gyrus and middle temporal gyrus, which was not compensated for by enhanced inhibitory alpha (11 Hz) connectivity between these regions. For the beta frequency, we also found in highly impulsive individuals that (i) both left and right middle temporal lobes directly influenced the activity of the left and right superior frontal lobes, and (ii) a clear decoupling between left and right superior frontal lobes. These findings could indicate reduced control by the supervisory system in more impulsive individuals

Optimal design of phononic media through genetic algorithm-informed pre-stress for the control of antiplane wave propagation

In this paper we employ genetic algorithms in order to theoretically design a range of phononic media that can act to prevent or ensure antiplane elastic wave propagation over a specific range of low frequencies, with each case corresponding to a specific pre-stress level. The medium described consists of an array of cylindrical annuli embedded inside an elastic matrix. The annuli are considered as capable of large strain and their constitutive response is described by the popular Mooney–Rivlin strain energy function. The simple nature of the medium described is an alternative approach to topology optimization in phononic media, which although useful, often gives rise to complex phase distributions inside a composite material, leading to more complicated manufacturing requirements

Surrounding skin management in venous leg ulcers: A systematic review

Objectives: Chronic venous insufficiency may lead to the development of venous leg ulcers, the most common form of chronic wounds in the lower extremity. Key to venous leg ulcer care is the maintenance of healthy skin surrounding the ulcer, as failure to maintain skin integrity may influence the healing outcome. We thus reviewed the scientific literature looking for assessment and management instruments regarding this common but often neglected issue. Method: The search included all studies published between 2000 and May 2019. Keywords used were: “peri-wound skin care”, “surrounding skin venous ulcers”, “surrounding skin management leg ulcers”, and “peri-lesional skin management”. Results: Management of moisture-balance with the selection of appropriate dressings is the most important target in surrounding-wound skin care. Moreover, contact dermatitis related to products and the dressings themselves is a neglected problem in patients with chronic leg ulcers which clinicians increasingly have to manage. The literature search revealed that there is an increasing interest in the use of noninvasive assessment tools in the field of wound care, and focusing on the surrounding-wound skin plays a role in assessing the potential of wound healing. Transepidermal water loss measurement (TEWL) and ultrasonography are two of the measurement techniques available. Conclusion: The integrity of the surrounding skin is necessary for wound healing, and appropriate management is needed to address this aspect which is part of an overall approach to treating wounds

Characterization of Composites Manufactured Through Reshaping of EoL Thermoplastic Polymers Reinforced with Recycled Carbon Fibers

This article investigates if and at what extent a recycling process based on grinding, melting and re-shaping of recycled carbon fibers reinforced thermoplastic polymers (rCFRPs) can affect their physical, mechanical and thermal properties. The aim is to establish if they can be taken into consideration in the manufacturing of new composite materials in different sectors: automotive, marine, sporting goods, etc. Composites materials were submitted to the measurement of the fibers length they are composed of, and then analyzed by means of tensile and impact tests and a dynamic mechanical analysis (DMA). All the characterizations were performed to both initial and recycled composites and, in some cases, they were replied also after the intermediate accelerated aging. Characterization performed confirmed that, as expected, the recycling process affects the properties of the composites, but in different manners and to a different extent when different polymers are involved. Tensile and impact tests pointed out that the polypropylene based composites showed a less stiff and a more brittle behaviour after the recycling process and the DMA confirmed this evidence, highlighting in addition a more viscous behavior of the polymer after the recycling. Conversely, the polyamide 6 based composites increased their stiffness and ductility after the recycling. For all the composites the tensile strength dropped, confirming the weakening of the materials

The determination of functional asymmetries in the lower limbs of young soccer players using the countermovement jump. The lower limbs asymmetry of young soccer players

Introduction. — This study investigated the functional asymmetries in the lower limbs of young soccer players using the countermovement jump (CMJ). Synthesis of the facts. — Fifteen young soccer players were assessed on the CMJ using two unilateral dynamometric force platforms equipped with software for the analysis of the movement. Conclusion. — The results indicate that the effects of functional asymmetries are important enough to require young soccer players to undergo a preventative screening before starting a sporting regime

Post-exposure prophylaxis with sotrovimab for Omicron (B.1.1.529) SARS-CoV-2 variant during the aplastic phase of autologous stem cell transplantation

Background To date, there is no information on the safety and efficacy of the novel anti-sarbecoviruses monoclonal antibody sotrovimab administered, as a post-exposure prophylactic measure, during the aplastic phase of autologous stem cell transplantation (ASCT). Methods We describe the outcomes of a Multiple Myeloma (MM) patient, who was threateningly exposed to the Omicron (B.1.1.529) SARS-CoV-2 variant, two days after having received a myeloablative regimen of high-dose melphalan. The patient fulfilled all CDC criteria for prolonged close contacts with an index patient who tested positive for a molecular nasopharyngeal swab (Omicron; B.1.1.529) soon after admission to the ward. Given the high risks of morbidity and mortality in the case of COVID-19 developing during the aplastic phase of transplantation, we adopted a post-exposure prophylaxis intervention based on intravenous (i.v.) sotrovimab

The social and healthcare professional support drawn upon by women antenatally during the COVID-19 pandemic:A recurrent, cross-sectional, thematic analysis

Objective: To explore antenatal experiences of social and healthcare professional support during different phases of social distancing restriction implementation in the UK. Design: Semi-structured interviews were conducted via telephone or video-conferencing software between 13 July 2020 – 2 September 2020. Interviews were transcribed and a recurrent, cross-sectional, thematic analysis was conducted. Participants: Twelve antenatal women were interviewed during UK social distancing restrictions (Timepoint 1; T1) and a separate sample of twelve women were interviewed in the initial easing of these restrictions (Timepoint 2; T2). Findings: T1 themes were: ‘Maternity care as non-essential’ and ‘Pregnancy is cancelled’. T2 themes were: ‘Technology is a polarised tool’ and ‘Clinically vulnerable, or not clinically vulnerable? That is the question’. Key conclusions: At T1, anxieties were ascribed to the exclusion of partners from routine care, and to perceived insensitivity and aggression from the public. For T2, insufficient Governmental transparency led to disillusionment, confusion, and anger. Covert workplace discrimination also caused distress at T2. Across timepoints: deteriorated mental wellbeing was attributed to depleted opportunities to interact socially and scaled back maternity care. Implications for practice: Recommendations are made to: protect maternal autonomy; improve quality of mental health and routine care signposting; prioritise parental community support in the re-opening of ‘non-essential’ services; prioritise the option for face-to-face appointments when safe and legal; and protecting the rights of working mothers.</p