Depletion forces near a soft surface

We investigate excluded-volume effects in a bidisperse colloidal suspension near a flexible interface. Inspired by a recent experiment by Dinsmore et al. (Phys. Rev, Lett. 80, 409 (1998)), we study the adsorption of a mesoscopic bead on the surface and show that depletion forces could in principle lead to particle encapsulation. We then consider the effect of surface fluctuations on the depletion potential itself and construct the density profile of a polymer solution near a soft interface. Surprisingly we find that the chains accumulate at the wall, whereas the density displays a deficit of particles at distances larger than the surface roughness. This non-monotonic behavior demonstrates that surface fluctuations can have major repercusions on the properties of a colloidal solution. On average, the additional contribution to the Gibbs adsorbance is negative. The amplitude of the depletion potential between a mesoscopic bead and the surface increases accordingly.Comment: 10 pages, 5 figure

UV-C Light-Based Surface Disinfection: Analysis of Its Virucidal Efficacy Using a Bacteriophage Model

Background: The reprocessing of medical devices has become more complex due to increasing hygiene requirements. Previous studies showed satisfactory bactericidal disinfection effects of UV-C light in rigid and flexible endoscopes. Especially in the context of the current COVID-19 pandemic, virucidal properties are of high importance. In the present study, the virucidal efficacy of UV-C light surface disinfection was analyzed. Methods: MS-2 bacteriophages were applied to the test samples and irradiated by UV-C light using the UV Smart D25 device; unirradiated test samples were used as controls. A dilution series of the samples was mixed with 1 × 108 Escherichia coli and assayed. Results: 8.6 × 1012 pfu could be harvested from the unprocessed test samples. In the control group without UV-C exposure, a remaining contamination of 1.2 × 1012 pfu was detected, resulting in a procedural baseline reduction rate with a LOG10 reduction factor of 0.72. The LOG10 reduction factor was found to be 3.0 after 25 s of UV-C light exposure. After 50 and 75 s of UV-C radiation LOG10 reduction factors 4.2 and 5.9, respectively, were found, with all reductions being statistically significantly different to baseline. Conclusions: The tested UV system seems to provide a significant virucidal effect after a relatively short irradiation time

Treatment of juvenile recurrent parotitis with irrigation therapy without anesthesia

Purpose!#!No standardized treatment regimen exists for juvenile recurrent parotitis (JRP). The investigators hypothesized that irrigation with saline only without local anesthesia will be an effective and beneficial option.!##!Methods!#!Using a retrospective study design, a series of children with typical symptoms of JRP who were treated with at least one irrigation therapy were evaluated. This treatment consisted of irrigation of the affected gland with 3-10 ml saline solution without any type of anesthesia. The outcome variables were patient/parent satisfaction, frequency and duration of acute JRP episodes, and the need for antibiotics before and after irrigation therapy.!##!Results!#!The case series was composed of six boys aged 3.3-7.7 years who experienced one to eight sessions of irrigation therapy. The period of follow-up was 9-64 months. We observed a total resolution of symptoms in two children and an improvement in the other four. No relevant side effects were seen.!##!Conclusion!#!Our results suggest that irrigation therapy is a reasonable, simple, and minimally invasive treatment alternative for JRP. In contrast to sialendoscopy or sialography, there is no need for general anesthesia or radiation exposure

UV light-based decontamination: an effective and fast way for disinfection of endoscopes in otorhinolaryngology?

Background!#!Reprocessing of endoscopes becomes increasingly complex, due to rising demands of hygiene. Established methods are often expensive/time-consuming. Recent studies suggest beneficial aspects of disinfection by UV light. In this study we analyzed the efficiency of UV light disinfection of rigid otorhinolaryngological endoscopes.!##!Materials and methods!#!After mechanical pre-cleaning, the endoscopes were decontaminated for 25 s in the D25 using Impelux™ UV C light technology (UV Smart B.V., Delft, The Netherlands). First, the surface contact samples were taken from 50 used endoscopes to evaluate the bacterial load. Additionally, surface contact samples were taken from further 50 used endoscopes after reprocessing with the D25. Another 50 endoscopes were tested on protein residuals. Furthermore, the absolute effectiveness of the D25 was tested on 50 test bodies (RAMS) with a standardized contamination of 10!##!Results!#!The used endoscopes showed a high bacterial contamination with an average value of 66.908 (± 239.215) CFU. After reprocessing, only a minimal contamination on 10% (n = 5) of the endoscopes with a mean value of 0.12 CFU (± 0.39) was found, resulting in a log-5 reduction in a clinical environment. The documented bacteria were components of the normal skin flora. All tested endoscopes were practically protein-free (< 1 μg). Furthermore, the average absolute germ reduction of the D25 was about 10!##!Conclusion!#!The D25 UV light system seems to be an effective device for the reprocessing of rigid ORL endoscopes, and therefore, might be suitable for the usage in clinical practice on site

UV light-based reprocessing of flexible endoscopes without working channel in Oto-Rhino-Laryngology: an effective method?

Background!#!Reprocessing of flexible endoscopes (FEs) is often expensive, time consuming, and becomes increasingly complex, due to rising demands of hygiene. After beneficial results in reprocessing of rigid endoscopes using Impelux™ UV-C light technology, we tested the same method for reprocessing of FEs without working channel.!##!Materials and methods!#!Testing was performed on FEs without working channel after routine clinical use (transnasal flexible endoscopy). Disinfection consisted of mechanical precleaning and 60 s exposure to Impelux™ UV-C light technology. Bacterial contamination was tested on 50 FEs before and after disinfection. Further 50 FEs regarding protein residuals. The absolute effectiveness of the D60 was tested on 50 test bodies (RAMS) with a standardized contamination of 10!##!Results!#!The FEs were contaminated with a high average value of 916.7 CFU (± 1057 CFU) after clinical usage. After reprocessing, an average contamination of 2.8 CFU (± 1.6) on 14% (n = 7) of the FEs was detected consisting of non-pathogenic species, the remaining FE were sterile. After reprocessing, all FEs were protein-free (< 1 μg). The artificially contaminated test bodies showed no remaining bacterial contamination after disinfection, resulting in an average absolute germ reduction of about 10!##!Conclusion!#!Impelux™ UV-C light technology efficiently reduces bacterial contamination of FEs and might be useful in daily practice

Natureza dos deuses e divindade da natureza: reflexões sobre a recepção antiga e moderna do antropomorfismo divino grego

A dificuldade em admitir-se o antropomorfismo dos deuses aparece na Grécia a partir da época arcaica, com os primeiros textos em prosa dos pensadores pré-socráticos. Neste estudo definirei as principais características dessa reflexão crítica sobre os limites do antropomorfismo, bem como a recusa dos intérpretes modernos em aceitar o antropomorfismo grego como uma experiência religiosa autêntica. Alguns fragmentos de Heráclito de Éfeso serão citados como exemplo da sabedoria dos jônios na época arcaica.<br>The difficulty in admitting divine anthropomorphism appears in Greece from the archaic epoch onwards with the first prose texts of the pre-Socratic thinkers. In this study I will define the main characteristics of this critical reflexion about the limits of anthropomorphism, as well as the modern scholars' refusal to accept it as an authentic religious experience. Some fragments of Heraclitus of Ephesus will be cited as an example of the Ionian wisdom of the archaic epoch