Design, Experimental and Numerical Characterization of 3D-Printed Porous Absorbers

The application of porous materials is a common measure for noise mitigation and in room acoustics. The prediction of the acoustic behavior applies material models, among which most are based on the BIOT-parameters. Thereby, it is expected that, if more BIOT-parameters are used, a better prediction can be obtained. Nevertheless, an estimation of the BIOT-parameters from the geometric design of the material is possible for simple structures only. For common porous materials, the microstructure is typically unknown and characterized by homogenized quantities. This contribution introduces a methodology that enables the design and optimization of porous materials based on the BIOT-parameters and connects these to microscopic geometric quantities. Therefore, artificial porous materials were manufactured using 3D-printing technology with a prescribed geometric design and the influence of different design variables was investigated. The BIOT-parameters were identified with an inverse procedure and it can be shown that different BIOT-parameters can be influenced by adjusting the geometric design variables. Based on these findings, a one-parameter optimization procedure of the material is set up to maximize the absorption characteristics in the frequency range of interest

Alterations of Glucosylceramide-β-Glucosidase Levels in the Skin of Patients with Psoriasis Vulgaris

Hydrolysis of glucosylceramides by the enzyme glucosylceramide-β-glucosidase (GlcCer'ase) results in ceramide, a critical component of the intercellular lamellae that mediates the epidermal permeability barrier. A disturbance of ceramide formation is supposed to influence the transepidermal water loss in common skin diseases like atopic eczema or psoriasis. The aim of this study was to investigate whether GlcCer'ase levels were altered in the skin of subjects with psoriasis vulgaris. Skin punch biopsies were taken from lesional and non-lesional psoriatic skin and GlcCer'ase was evaluated both at the RNA and at the protein level. Normal skin from surgical patients provided the baseline GlcCer'ase expression in healthy subjects. Our results show that GlcCer'ase mRNA expression was decreased in psoriatic non-lesional skin compared to normal controls in all cases. Interestingly, in lesional psoriatic skin the level of GlcCer'ase was increased compared to non-lesional skin in all cases. For the immunohistochemical analysis, we used a newly synthesized monoclonal antibody anti-human GBC (GlcCer'ase-GST fusion protein). The results confirmed that GlcCer'ase, mainly present in the upper epidermis, was decreased in psoriatic skin compared to normal control and was increased in lesional compared to non-lesional psoriatic skin. Our findings support the concept that alteration in water permeability barrier in lesional psoriatic skin can serve as a trigger for the upregulation of the expression of enzymes like GlcCer'ase with consequent stimulation of ceramide generation

ATP and Its Metabolite Adenosine as Regulators of Dendritic Cell Activity

Adenosine (Ado) is a well-studied neurotransmitter, but it also exerts profound immune regulatory functions. Ado can (i) actively be released by various cells into the tissue environment and can (ii) be produced through the degradation of extracellular ATP by the concerted action of CD39 and CD73. In this sequence of events, the ectoenzyme CD39 degrades ATP into ADP and AMP, respectively, and CD73 catalyzes the last step leading to the production of Ado. Extracellular ATP acts as a “danger” signal and stimulates immune responses, i.e. by inflammasome activation. Its degradation product Ado on the other hand acts rather anti-inflammatory, as it down regulates functions of dendritic cells (DCs) and dampens T cell activation and cytokine secretion. Thus, the balance of proinflammatory ATP and anti-inflammatory Ado that is regulated by CD39+/CD73+ immune cells, is important for decision making on whether tolerance or immunity ensues. DCs express both ectoenzymes, enabling them to produce Ado from extracellular ATP by activity of CD73 and CD39 and thus allow dampening of the proinflammatory activity of adjacent leukocytes in the tissue. On the other hand, as most DCs express at least one out of four so far known Ado receptors (AdoR), DC derived Ado can also act back onto the DCs in an autocrine manner. This leads to suppression of DC functions that are normally involved in stimulating immune responses. Moreover, ATP and Ado production thereof acts as “find me” signal that guides cellular interactions of leukocytes during immune responses. In this review we will state the means by which Ado producing DCs are able to suppress immune responses and how extracellular Ado conditions DCs for their tolerizing properties

Neutrophils orchestrate post-myocardial infarction healing by polarizing macrophages towards a reparative phenotype

Aims Acute myocardial infarction (MI) is the leading cause of mortality worldwide. Anti-inflammatory strategies to reduce neutrophil-driven acute post-MI injury have been shown to limit acute cardiac tissue damage. On the other hand, whether neutrophils are required for resolving post-MI inflammation and repair is unknown. Methods and results We show that neutrophil-depleted mice subjected to MI had worsened cardiac function, increased fibrosis, and progressively developed heart failure. Flow cytometry of blood, lymphoid organs and digested hearts revealed reduced numbers of Ly6C(high) monocytes in infarcts of neutrophil-depleted mice, whereas the number of macrophages increased, which was paralleled by reduced splenic Ly6C(high) monocyte mobilization but enhanced proliferation of cardiac macrophages. Macrophage subtype analysis revealed reduced cardiac expression of M1 markers, whereas M2 markers were increased in neutrophil-depleted mice. Surprisingly, we found reduced expression of phagocytosis receptor myeloid-epithelial-reproductive tyrosine kinase, a marker of reparative M2c macrophages which mediate clearance of apoptotic cells. In agreement with this finding, neutrophil-depleted mice had increased numbers of TUNEL-positive cells within infarcts. We identified neutrophil gelatinase-associated lipocalin (NGAL) in the neutrophil secretome as a key inducer of macrophages with high capacity to engulf apoptotic cells. The cardiac macrophage phenotype in neutrophil-depleted mice was restored by administration of neutrophil secretome or NGAL. Conclusion Neutrophils are crucially involved in cardiac repair after MI by polarizing macrophages towards a reparative phenotype. Therapeutic strategies to reduce acute neutrophil-driven inflammation after MI should be carefully balanced as they might interfere with the healing response and cardiac remodelling

Medien, Interfaces und implizites Wissen

Die Beiträge des Heftes zeigen auf, wie sich das Verhältnis von Medien und implizitem Wissen unter den Bedingungen des Internets der Dinge, im Kontext der Robotik oder in Bezug auf ökonomische Fragen ausgestaltet. Erörtert werden dabei vorrangig Fragestellungen, die an die Interfaces dieser zeitgenössischen Medientechnologien gerichtet werden können. Vor dem Hintergrund medien- und interfacetheoretischer Überlegungen wird aufgezeigt, welche medienwissenschaftlichen Konsequenzen sich für die Analyse dieser kulturellen Phänomene und gesellschaftlichen Felder ergeben

Sound quality assessment of a medium-range aircraft with enhanced fan-noise shielding design

The investigation of technologies that can improve the sustainability of the air transport system requires not only the development of alternative fuel concepts and novel vehicle technologies but also the definition of appropriate assessment strategies. Regarding noise, the assessment should reflect the situation of communities living near airports, i.e., not only addressing sound levels but also accounting for the annoyance caused by aircraft noise. For this purpose, conventional A-weighted sound pressure level metrics provide initial but limited information as the level- and frequency-dependency of the human hearing is accounted for in a simplified manner. Ideally, subjective evaluations are required to adequately quantify the perceived short-term annoyance associated with aircraft noise. However, listening tests are time-consuming and not suitable to be applied during the conceptual aircraft design stage, where a large solution space needs to be explored. Aiming at bridging this gap, this work presents a methodology for the sound quality assessment of computational aircraft noise predictions, which is hereby conducted in terms of objective psychoacoustic metrics. The proposed methodology is applied to a novel medium-range vehicle with fan noise shielding architecture during take-off and landing procedures. The relevance of individual sound sources, i.e., airframe and engine noise contributions, and their dependencies on the aircraft architecture and flight procedures are assessed in terms of loudness, sharpness, and tonality. Moreover, the methodology is steered towards community noise assessment, where the impacts on short-term annoyance brought by the novel aircraft design are analysed. The assessment is based on the modified psychoacoustic annoyance, a metric that provides a quantitative description of human annoyance as a combination of different hearing sensations. The present work is understood as an essential step towards low-annoyance aircraft design

Physiology and pathology of eosinophils: Recent developments: Summary of the Focus Workshop Organized by DGAKI.

Over the last century, eosinophils have been regarded ambiguously either as 'friends' or 'foes'. Recent developments have greatly enhanced our understanding of the role and function of eosinophils in health and disease. Pathogenic eosinophilic inflammation can lead to severe diseases in various organs, such as the gastrointestinal tract, airways, heart and skin. In a 2-day focus workshop of the German Society for Allergology and Clinical Immunology (DGAKI), the state of the art was discussed and practical recommendations for diagnosis and treatment of eosinophilic diseases, with a particular focus on new biologics, such as anti-interleukin 5 and anti-interleukin 5R, were derived

Palmitoylethanolamide Promotes a Proresolving Macrophage Phenotype and Attenuates Atherosclerotic Plaque Formation

Objective Palmitoylethanolamide is an endogenous fatty acid mediator that is synthetized from membrane phospholipids by N-acyl phosphatidylethanolamine phospholipase D. Its biological actions are primarily mediated by PPAR- (peroxisome proliferator-activated receptors ) and the orphan receptor GPR55. Palmitoylethanolamide exerts potent anti-inflammatory actions but its physiological role and promise as a therapeutic agent in chronic arterial inflammation, such as atherosclerosis remain unexplored. Approach and Results First, the polarization of mouse primary macrophages towards a proinflammatory phenotype was found to reduce N-acyl phosphatidylethanolamine phospholipase D expression and palmitoylethanolamide bioavailability. N-acyl phosphatidylethanolamine phospholipase D expression was progressively downregulated in the aorta of apolipoprotein E deficient (ApoE(-/-)) mice during atherogenesis. N-acyl phosphatidylethanolamine phospholipase D mRNA levels were also downregulated in unstable human plaques and they positively associated with smooth muscle cell markers and negatively with macrophage markers. Second, ApoE(-/-) mice were fed a high-fat diet for 4 or 16 weeks and treated with either vehicle or palmitoylethanolamide (3 mg/kg per day, 4 weeks) to study the effects of palmitoylethanolamide on early established and pre-established atherosclerosis. Palmitoylethanolamide treatment reduced plaque size in early atherosclerosis, whereas in pre-established atherosclerosis, palmitoylethanolamide promoted signs of plaque stability as evidenced by reduced macrophage accumulation and necrotic core size, increased collagen deposition and downregulation of M1-type macrophage markers. Mechanistically, we found that palmitoylethanolamide, by activating GPR55, increases the expression of the phagocytosis receptor MerTK (proto-oncogene tyrosine-protein kinase MER) and enhances macrophage efferocytosis, indicative of proresolving properties. Conclusions The present study demonstrates that palmitoylethanolamide protects against atherosclerosis by promoting an anti-inflammatory and proresolving phenotype of lesional macrophages, representing a new therapeutic approach to resolve arterial inflammation

A comparative study of semi-empirical noise emission models based on the PANAM and sonAIR aircraft noise simulation tools

In the context of aircraft noise simulations, an accurate representation of the aircraft noise sources is crucial so that reliable predictions can be obtained. In this contribution, we present a comparative study between the predictions provided by the emission models based on the DLR’s in-house PANAM tool and the sonAIR simulation software. Both are based on semi-empirical descriptions of the engine and airframe noise contributions, meaning that the emission levels are modeled separately for each noise source according to the operational conditions of the aircraft. This allows the comparison of the emission models not only in terms of the aircraft’s overall noise levels, but also regarding its different noise sources. The comparative study considers models representing the noise emissions of an A319 aircraft, which are provided by both simulation tools but further simulated within the sonAIR software environment in order to yield noise immission levels on a large calculation area. In general, a good agreement is observed for the departure procedure due to the similar performance of the engine noise models. In contrast, larger differences are observed during the approach procedure and at larger distances from the runway, which might be explained by differences in the airframe noise models

Identifying and managing patients at risk of severe allergic reactions to food: report from two iFAAM workshops

Food allergy affects a small but important number of children and adults. Much of the morbidity associated with food allergy is driven by the fear of a severe reaction, and fatalities continue to occur. Foods are the commonest cause of anaphylaxis. One of the aims of the European Union funded Integrated Approaches to Food Allergen and Allergy Risk Management (iFAAM) project was to improve the identification and management of children and adults at risk of experiencing a severe reaction. A number of interconnected studies within the project have focused on quantifying the severity of allergic reactions; the impact of food matrix, immunological factors on severity of reactions; the impact of co‐factors such as medications on the severity of reactions; utilising single dose challenges to understand threshold and severity of reactions; and community studies to understand the experience of patients suffering real‐life allergic reactions to food. Associated studies have examined population thresholds, and co‐factors such as exercise and stress. This paper summarises two workshops focused on the severity of allergic reactions to food. It outlines the related studies being undertaken in the project indicating how they are likely to impact on our ability to identify individuals at risk of severe reactions and improve their management