Spreading of thin films assisted by thermal fluctuations

We study the spreading of viscous drops on a solid substrate, taking into account the effects of thermal fluctuations in the fluid momentum. A nonlinear stochastic lubrication equation is derived, and studied using numerical simulations and scaling analysis. We show that asymptotically spreading drops admit self-similar shapes, whose average radii can increase at rates much faster than these predicted by Tanner's law. We discuss the physical realizability of our results for thin molecular and complex fluid films, and predict that such phenomenon can in principal be observed in various flow geometries.Comment: 5 pages, 3 figure

Capillary deformations of bendable films

We address the partial wetting of liquid drops on ultrathin solid sheets resting on a deformable foundation. Considering the membrane limit of sheets that can relax compression through wrinkling at negligible energetic cost, we revisit the classical theory for the contact of liquid drops on solids. Our calculations and experiments show that the liquid-solid-vapor contact angle is modified from the Young angle, even though the elastic bulk modulus (E) of the sheet is so large that the ratio between the surface tension γ and E is of molecular size. This finding establishes a new type of “soft capillarity” that stems from the bendability of thin elastic bodies rather than from material softness. We also show that the size of the wrinkle pattern that emerges in the sheet is fully predictable, thus resolving a puzzle noticed in several previous attempts to model “drop-on-a-floating-sheet” experiments, and enabling a reliable usage of this setup for the metrology of ultrathin films

Seeking a second medical opinion: composition, reasons and perceived outcomes in Israel.

Background: Seeking a second-opinion (SO) is a common clinical practice that can optimize treatment and reduce unnecessary procedures and risks. We aim to characterize the composition of the population of SO seekers, their reasons for seeking a SO and choosing a specific physician, and their perceived outcomes following the SO. Methods: A cross-sectional national telephone survey, using a representative sample of the general Israeli population (n = 848, response rate = 62%). SO utilization was defined as seeking an additional clinical opinion from a specialist within the same specialty, for the same medical concern. We describe the characteristics of respondents who obtained SOs, their reasons for doing so and their perceived outcomes: (1) Satisfaction with the SO; (2) Experiencing health improvement after receiving a SO; (3) A difference in the diagnosis or treatment suggested in the first opinions and the second opinions; (4) Preference of the SO over the first one. Results: Most of the respondents who sought a SO (n = 344) were above 60 years old, secular, living with a partner, perceived their income to be above average and their health status to be not so good. For the patients who utilized SOs, orthopedic surgeons were sought out more than any other medical professional.Reasons for seeking a SO included doubts about diagnosis or treatment (38%), search for a sub-specialty expert (19%) and dissatisfaction with communication (19%). SO seekers most frequently chose a specific specialist based on a recommendation from a friend or a relative (33%). About half of the SO seekers also searched for information on the internet. Most of the respondents who sought a SO mentioned that they were satisfied with it (84%), felt health improvement (77%), mentioned that there was a difference between the diagnosis or treatment between the first opinion and the SO (56%) and preferred the SO over the first one (91%). Conclusions: Clinical uncertainty or dissatisfaction with patient-physician communication were the main reasons for seeking a SO. Policy makers should be aware that many patients choose a physician for a SO based on recommendations made outside the medical system. We recommend creating mechanisms that help patients in the complicated process of seeking a SO, suggest specialists who are suitable for the specific medical problem of the patient, and provide tools to reconcile discrepant opinions

Bi-Laplacian Growth Patterns in Disordered Media

Experiments in quasi 2-dimensional geometry (Hele Shaw cells) in which a fluid is injected into a visco-elastic medium (foam, clay or associating-polymers) show patterns akin to fracture in brittle materials, very different from standard Laplacian growth patterns of viscous fingering. An analytic theory is lacking since a pre-requisite to describing the fracture of elastic material is the solution of the bi-Laplace rather than the Laplace equation. In this Letter we close this gap, offering a theory of bi-Laplacian growth patterns based on the method of iterated conformal maps.Comment: Submitted to PRL. For further information see http://www.weizmann.ac.il/chemphys/ander

Exact Multifractal Spectra for Arbitrary Laplacian Random Walks

Iterated conformal mappings are used to obtain exact multifractal spectra of the harmonic measure for arbitrary Laplacian random walks in two dimensions. Separate spectra are found to describe scaling of the growth measure in time, of the measure near the growth tip, and of the measure away from the growth tip. The spectra away from the tip coincide with those of conformally invariant equilibrium systems with arbitrary central charge $c\leq 1$, with $c$ related to the particular walk chosen, while the scaling in time and near the tip cannot be obtained from the equilibrium properties.Comment: 4 pages, 3 figures; references added, minor correction

Patient-initiated second medical consultations: patient characteristics and motivating factors, impact on care and satisfaction: A systematic review

Objectives: To review the characteristics and motivations of patients seeking second opinions, and the impact of such opinions on patient management, satisfaction, and cost-effectiveness. Data sources: Embase, Medline, PsycINFO and HMIC databases. Study design: A systematic literature search was performed for terms related to second opinion and patient characteristics. Study quality was assessed using the National Institutes of Health (NIH) Quality Assessment Tool for Observational Cohort and Cross-Sectional Studies. Data collection / Extraction methods: We included articles focused on patient-initiated second opinions, which provided quantitative data on their impact on diagnosis, treatment, prognosis or patient satisfaction, described the characteristics or motivating factors of patients who initiated a second opinion, or the cost-effectiveness of patient-initiated second opinions. Principal findings: Thirty-one articles were included in the review. 27 studies considered patient characteristics, 18 patient motivating factors, 10 patient satisfaction, and 17 clinical agreement between the first and second opinion. Seeking a second opinion was more common in women, middle age patients, more educated patients; and in people having a chronic condition, with higher income or socioeconomic status or living in central urban areas. Patients seeking a second opinion sought to gain more information or reassurance about their diagnosis or treatment. While many second opinions confirm the original diagnosis or treatment, discrepancies in opinions had a potential major impact on patient outcomes in up to 58% of cases. No studies reporting on the cost-effectiveness of patient initiated second opinions. Conclusions: Seeking a second opinion was more common in women, middle-age patients, and more educated patients, and in people having a chronic condition, with higher income or socioeconomic status or living in central urban areas. Patients seeking a second opinion sought to gain more information or reassurance about their diagnosis or treatment

Recognition of COVID-19 with occupational origin: a comparison between European countries

Objectives This study aims to present an overview of the formal recognition of COVID-19 as occupational disease (OD) or injury (OI) across Europe. Methods A COVID-19 questionnaire was designed by a task group within COST-funded OMEGA-NET and sent to occupational health experts of 37 countries in WHO European region, with a last update in April 2022. Results The questionnaire was filled out by experts from 35 countries. There are large differences between national systems regarding the recognition of OD and OI: 40% of countries have a list system, 57% a mixed system and one country an open system. In most countries, COVID-19 can be recognised as an OD (57%). In four countries, COVID-19 can be recognised as OI (11%) and in seven countries as either OD or OI (20%). In two countries, there is no recognition possible to date. Thirty-two countries (91%) recognise COVID-19 as OD/OI among healthcare workers. Working in certain jobs is considered proof of occupational exposure in 25 countries, contact with a colleague with confirmed infection in 19 countries, and contact with clients with confirmed infection in 21 countries. In most countries (57%), a positive PCR test is considered proof of disease. The three most common compensation benefits for COVID-19 as OI/OD are disability pension, treatment and rehabilitation. Long COVID is included in 26 countries. Conclusions COVID-19 can be recognised as OD or OI in 94% of the European countries completing this survey, across different social security and embedded occupational health systems.This publication is based on work from COST Action CA16216 (OMEGA-NET), supported by COST (European Cooperation in Science and Technology)