Microstructural morphology and visual acuity outcome in eyes with epiretinal membrane before, during, and after membrane peeling in intraoperative optical coherence tomography assisted macular surgery

AIM: To measure the difference of intraoperative central macular thickness (CMT) before, during, and after membrane peeling and investigate the influence of intraoperative macular stretching on postoperative best corrected visual acuity (BCVA) outcome and postoperative CMT development. METHODS: A total of 59 eyes of 59 patients who underwent vitreoretinal surgery for epiretinal membrane was analyzed. Videos with intraoperative optical coherence tomography (OCT) were recorded. Difference of intraoperative CMT before, during, and after peeling was measured. Pre- and postoperatively obtained BCVA and spectral-domain OCT images were analyzed. RESULTS: Mean age of the patients was 70±8.13y (range 46-86y). Mean baseline BCVA was 0.49±0.27 logMAR (range 0.1-1.3). Three and six months postoperatively the mean BCVA was 0.36±0.25 (P=0.01 vs baseline) and 0.38±0.35 (P=0.08 vs baseline) logMAR respectively. Mean stretch of the macula during surgery was 29% from baseline (range 2%-159%). Intraoperative findings of macular stretching did not correlate with visual acuity outcome within 6mo after surgery (r=-0.06, P=0.72). However, extent of macular stretching during surgery significantly correlated with less reduction of CMT at the fovea centralis (r=-0.43, P<0.01) and 1 mm nasal and temporal from the fovea (r=-0.37, P=0.02 and r=-0.50, P<0.01 respectively) 3mo postoperatively. CONCLUSION: The extent of retinal stretching during membrane peeling may predict the development of postoperative central retinal thickness, though there is no correlation with visual acuity development within the first 6mo postoperatively

Topical and systemic antifungal therapy for chronic rhinosinusitis

Background: This review adds to a series of reviews looking at primary medical management options for patients with chronic rhinosinusitis.  Chronic rhinosinusitis is common and characterised by inflammation of the lining of the nose and paranasal sinuses leading to nasal blockage, nasal discharge, facial pressure/pain and loss of sense of smell. The condition can occur with or without nasal polyps. Antifungals have been suggested as a treatment for chronic rhinosinusitis.  Objectives: To assess the effects of systemic and topical antifungal agents in patients with chronic rhinosinusitis, including those with allergic fungal rhinosinusitis (AFRS) and, if possible, AFRS exclusively.  Search methods: The Cochrane ENT Information Specialist searched the Cochrane ENT Trials Register; Cochrane Central Register of Controlled Trials (CENTRAL); Ovid MEDLINE; Ovid Embase; CINAHL; Web of Science; ClinicalTrials.gov; ICTRP and additional sources for published and unpublished trials. The date of the search was 17 November 2017.  Selection criteria: Randomised controlled trials (RCTs) with at least a two‐week follow‐up period comparing topical or systemic antifungals with (a) placebo, (b) no treatment, (c) other pharmacological interventions or (d) a different antifungal agent. We did not include post‐surgical antifungal use.  Data collection and analysis: We used the standard Cochrane methodological procedures. Our primary outcomes were disease‐specific health‐related quality of life (HRQL), patient‐reported disease severity and the significant adverse effects of hepatic toxicity (systemic antifungals). Secondary outcomes included general HRQL, endoscopic nasal polyp score, computerised tomography (CT) scan score and the adverse effects of gastrointestinal disturbance (systemic antifungals) and epistaxis, headache or local discomfort (topical antifungals). We used GRADE to assess the quality of the evidence for each outcome; this is indicated in italics.  Main results: We included eight studies (490 adult participants). The presence of nasal polyps on examination was an inclusion criterion in three studies, an exclusion criterion in one study and the remaining studies included a mixed population. No studies specifically investigated the effect of antifungals in patients with AFRS.  Topical antifungal treatment versus placebo or no intervention  We included seven studies (437 participants) that used amphotericin B (six studies; 383 participants) and one that used fluconazole (54 participants). Different delivery methods, volumes and concentrations were used.  Four studies reported disease‐specific health‐related quality of life using a range of instruments. We did not meta‐analyse the results due to differences in the instruments used, and measurement and reporting methods. At the end of treatment (one to six months) none of the studies reported statistically significant differences between the groups (low‐quality evidence ‐ we are uncertain about the result).  Two studies reported disease severity using patient‐reported symptom scores. Meta‐analysis was not possible. At the end of treatment (8 to 13 weeks) one study showed no difference and the second found that patients in the placebo group had less severe symptoms (very low‐quality evidence ‐ we are very uncertain about the result).  In terms of adverse effects , topical antifungals may lead to more local irritation compared with placebo (risk ratio (RR) 2.29, 95% confidence interval (CI) 0.61 to 8.62; 312 participants; 5 studies; low‐quality evidence) but little or no difference in epistaxis (RR 0.97, 95% CI 0.14 to 6.63; 225 participants; 4 studies, low‐quality evidence) or headache (RR 1.26, 95% CI 0.60 to 2.63; 195 participants; 3 studies; very low‐quality evidence).  None of the studies found a difference in generic health‐related quality of life (one study) or endoscopic score (five studies) between the treatment groups. Three studies investigated CT scan ; two found no difference between the groups and one found a significant decrease in the mean percentage of air space occluded, favouring the antifungal group.  Systemic antifungal treatment versus placebo or no treatment  One study (53 participants) comparing terbinafine tablets against placebo reported that there may be little or no difference between the groups in disease‐specific health‐related quality of life or disease severity score (both low‐quality evidence). Systemic antifungals may lead to more hepatic toxicity events (RR 3.35, 95% CI 0.14 to 78.60) but fewer gastrointestinal disturbances (RR 0.37, 95% CI 0.04 to 3.36), compared to placebo, although the evidence was of low quality.  This study did not find a difference in CT scan score between the groups. Generic health‐related quality of life and endoscopic score were not measured.  Other comparisons: We found no studies that compared antifungal agents against other treatments for chronic rhinosinusitis.  Authors' conclusions: Due to the very low quality of the evidence, it is uncertain whether or not the use of topical or systemic antifungals has an impact on patient outcomes in adults with chronic rhinosinusitis compared with placebo or no treatment. Studies including specific subgroups (i.e. AFRS) are lacking

Role of Innate Immunity in the Pathogenesis of Chronic Rhinosinusitis: Progress and New Avenues

Chronic rhinosinusitis is a heterogeneous and multifactorial disease with unknown etiology. Aberrant responses to microorganisms have been suggested to play a role in the pathophysiology of the disease. Research has focused on the presence, detection, response to, and eradication of these potential threats. Main topics seem to center on the contribution of structural cells such as epithelium and fibroblasts, on the consequences of activation of pattern-recognition receptors, and on the role of antimicrobial agents. This research should be viewed not only in the light of a comparison between healthy and diseased individuals, but also in a comparison between patients who do or do not respond to treatment. New players that could play a role in the pathophysiology seem to surface at regular intervals, adding to our understanding (and the complexity) of the disease and opening new avenues that may help fight this incapacitating disease

International Consensus Statement on Rhinology and Allergy: Rhinosinusitis

Background: The 5 years since the publication of the first International Consensus Statement on Allergy and Rhinology: Rhinosinusitis (ICAR‐RS) has witnessed foundational progress in our understanding and treatment of rhinologic disease. These advances are reflected within the more than 40 new topics covered within the ICAR‐RS‐2021 as well as updates to the original 140 topics. This executive summary consolidates the evidence‐based findings of the document. Methods: ICAR‐RS presents over 180 topics in the forms of evidence‐based reviews with recommendations (EBRRs), evidence‐based reviews, and literature reviews. The highest grade structured recommendations of the EBRR sections are summarized in this executive summary. Results: ICAR‐RS‐2021 covers 22 topics regarding the medical management of RS, which are grade A/B and are presented in the executive summary. Additionally, 4 topics regarding the surgical management of RS are grade A/B and are presented in the executive summary. Finally, a comprehensive evidence‐based management algorithm is provided. Conclusion: This ICAR‐RS‐2021 executive summary provides a compilation of the evidence‐based recommendations for medical and surgical treatment of the most common forms of RS

Neuronales Hybridsystem zur Klassifizierung dynamischer dreidimensionaler Gesten

Computer Vision bietet bereits unterschiedliche Ansätze zur Erkennung menschlicher Gesten. In dieser Thesis wird dazu eine neuartige Kombination von Ansätzen der Objekt- und Gestenerkennung, unter Verwendung von künstlichen neuronalen Netzen vorgestellt, um dynamische und detailreiche Gesten der Gebärdensprache zu klassiffzieren. Um die Komplexität solcher Gesten erfassen zu können werden drei unterschiedliche Gesteninformationen genutzt. Die gewonnenen Daten dieser Teilsysteme werden mittels von einander unabhängigen neuronalen Netzen ausgewertet. Ein finales neuronales Netz fasst diese Auswertungen zusammen und klassiffziert die Bedeutung der Geste. Die Eigenschaften und Ergebnisse dieses Hybridsystems und seiner Teilsysteme werden untersucht und diskutiert.Computer vision already offers various approaches for recognizing human gestures. This thesis presents a new combination of approaches of object- and gesture-recognition with neural networks, for recognizing daynamic and detailed gestures of Sign Language. To acquire the complexity of such gestures, three different types of information of these gestures are exploited. The gathered data is evaluated in three independent neural networks. A final neural network pools these subsystems and classffes the gesture. The characteristics and results of this hybridsystem and its subsystems will be evalutated and discussed

Research into the mode of action of microtextures in elastohydrodynamic rolling-sliding contacts

Durch in den letzten Jahrzehnten gestiegene Anforderungen an Maschinenelemente und technische Systeme hinsichtlich ihrer Energieeffizienz arbeiteten auf Tribologie ausgerichtete Wissenschaften und Forschungsvorhaben zielgerichtet an Methoden und Verfahren zur Reibungsminderung. Hierdurch wurde unter anderem eine selektive Oberflächenbearbeitung als geeignete Lösung zur Reibungsreduktion identifiziert, die Oberflächenmerkmale im mikroskopischen Maßstab erzeugt. Die hergestellten Oberflächenänderungen können dabei in stochastisch verteilte, aber ausgerichtete Rillen und in diskrete Texturelemente unterteilt werden. In dieser Arbeit erfolgte eine Einschränkung auf die zuletzt genannten Formen. Ein positiver Effekt auf die Reibung konnte bisher allerdings nur für niedrigbelastete Gleitkontakte wie den Zylinder/Laufbahn-Kontakt nachgewiesen werden. Für elastohydrodynamische (EHD) Kontakte konnten demgegenüber noch keine klaren Aussagen getroffen werden. Ziel dieser Arbeit ist es daher einen Literaturüberblick zu bekannten Mechanismen diskreter Mikrotexturen in verschiedenen Kontaktsituationen zu geben, ein vertieftes Verständnis hinsichtlich der EHD-Wälz/Gleit-Kontakte zu entwickeln und einen Machbarkeitsnachweis für ihr Reibungsreduktionspotential in diesen Kontaktsituationen zu erbringen. Hierzu wurde ein Fokus auf numerische Studien und deren Umsetzung gelegt, aber auch Experimente durchgeführt. Zunächst erfolgten Reibungsmessungen an einem Nocken/Stößel-System, einem Vertreter der EHD-Wälz/Gleit-Kontakte der hauptsächlich im Bereich der Mischreibung betrieben wird. Hierzu wurden unterschiedliche Formen und Anordnungen von Mikrotexturen auf Tassenstößeln mit obenliegender Einstellscheibe aufgebracht. Im günstigsten Fall ergab sich dadurch ein Reibungsminderungspotential von bis zu 18 % im Vergleich zu einer polierten Referenzprobe. Der dabei ebenfalls erkannte Einlaufverschleiß bedarf noch einer weitergehenden Untersuchung. Des Weiteren wurde ein Simulationsmodell dieser Kontakte entwickelt um ähnlich einer „numerischen Lupe“ tiefer in mikrotexturierte Wälz/Gleit-Kontakte zu blicken und die auftretenden Mechanismen und Effekte besser verstehen zu können. Abweichend von der weit verbreiteten Herangehensweise an EHD-Fragestellungen mittels selbstentwickelter Programmcodes und sequenzieller numerischer Lösungsalgorithmen wurde die Entscheidung zugunsten kommerzieller FE-Software und eines, wo möglich, vollständig gekoppelten Lösungsansatzes getroffen. Der Abgleich mit Daten aus der Literatur belegte die Machbarkeit dieses Ansatzes und zeigte nur kleine Abweichungen, die sich durch Unterschiede in der numerischen Implementierung erklären ließen. Daran schloss sich eine breite Studie zu nicht-newtonschen und thermischen Effekten, sowie zu verschiedenen Mikrotexturformen und Belastungssituationen an. Diese Studien lieferten Erkenntnisse über die Bedeutung von Gleiteffekten und gemäßigten Belastungen bei gleichzeitig ausreichend hoher Schmierstoffviskosität sowie günstigen Mikrotexturdimensionen. Zusammenfassend liefert diese Arbeit durch Ihre Simulationsergebnisse weitere Einblicke in mikrotexturierte EHD-Kontakte, während die Experimente ihr Potential zur Reibungsreduzierung aufzeigen.Due to increased requirements for machine elements and technical systems with regard to their energy efficiency, in the last decades there has been a focus in tribology oriented sciences and research on methods and treatments to reduce friction. Amongst others, a selective surface machining defining surface features on a microscopic scale was found to be an appropriate solution for friction reduction. These surface features can be divided into stochastically distributed yet oriented grooves or discrete surface features. Focusing on the latter in this thesis, a positive effect on friction has mainly been proven in literature for low loaded sliding contacts as the cylinder/liner-contact whereas no clear decision has been taken for elastohydrodynamic (EHL) contacts. The goal of this thesis therefore is to provide a literature overview of the known mechanisms of discrete microtextures in different contact situations, to develop a deeper understanding regarding rolling-sliding EHL contacts as well as to perform a proof of concept for their friction reduction potential in these contact situations. To achieve this, a focus was made on numerical studies and their implementation but also experiments were undertaken. First, friction measurements in a cam/follower tribo system – representing rolling-sliding EHL contacts and running mostly in mixed lubrication – were conducted. Therefore, different shapes and arrangements of microtextures were applied on flatbase tappets. A friction reduction potential of up to 18 % compared to a polished surface reference resulted in best case. But also a noteworthy amount of running in wear had to be detected that needs deeper investigations. Second, resembling a “numerical loupe” and in order to look deeper into microtextured rolling/sliding EHL contacts and the mechanisms and effects occurring, a simulation model of these contacts was developed. Deviating from the widespread approach in EHL research of self-developed program codes and sequential numerical solution algorithms, the decision was made in favor of adopting commercial FE software and using a fully-coupled solution approach where appropriate. Extended comparison with data from literature proved the feasibility of this approach and showed only small deviations that could be explained with differences in the numerical implementation. This was followed up by a broad study of non-newtonian and thermal effects as well as of different microtexture shapes and loading conditions. These studies provided findings for the importance of slip effects and medium loading conditions but high enough lubricant viscosity as well as favorable microtexture dimensions. Summarizing, this thesis provides further insights into microtextured EHL contacts from a numerical point of view while giving confident prospects for their friction reduction potential in experiments

Simulation of Microstructured Rolling-Sliding Contacts

Abstract: To reduce friction in lubricated tribological contacts, the surfaces of the contacting bodies can be microstructured to improve lubricating conditions. For lower loaded contacts this approach has already reached industrial applications, e.g. the piston-liner contact. For higher loaded contacts the effects are currently in basic research. Elastic deformation in the contact area plays an important role in those cases. This paper presents an approach to compute microstructured elastohydrodynamic contacts using Comsol Multiphysics and compares results with those attained on a test bench