1,074 research outputs found
Einsatz der optischen Kohärenztomographie zur kontinuierlichen Überwachung von Scaling bei der Membrandestillation
Die Membrandestillation (MD) ist ein junges und innovatives Verfahren zur thermischen Aufbereitung hoch saliner Wässer. Die Separation anhand einer hydrophoben Membran wird durch den Phasenübergang von volatilen Komponenten bei gleichzeitigem Rückhalt der flüssigen Bestandteile erreicht. Im (Langzeit-)Betrieb bilden sich häufig Deckschichten, die bei hoch salzigen Wässern hauptsächlich aus Scaling bestehen und zu einem Rückgang des Permeatstroms und einer Verschlechterung der Permeatqualität führen können. Die Detektion des Permeatstroms ist derzeit die Methode der Wahl, um auf die Bildung von Scaling zu schließen. Ein ganzheitliches, nicht invasives Monitoring der Membran im laufenden MD-Betrieb existiert nicht und auch die Bestätigung von Scaling auf der Membran wird vornehmlich ex situ nach Abschluss des Experiments durchgeführt. In der vorliegenden Arbeit wurde, basierend auf der optischen Kohärenztomographie (OCT), eine Methode zur sicheren Visualisierung und Quantifizierung von anorganischen Deckschichten entwickelt und im laufenden MD-Betrieb angewandt.
In einer vollautomatisierten Membrandestillationslaboranlage wurden konzentriertes Ostseewasser (OstWK) und Leitungswasser der Stadt Karlsruhe (KALW) behandelt und das Wachstum der Deckschicht auf den Einfluss variierender Prozessparameter mittels OCT untersucht. An einer manuellen Membrandestillationslaboranlage wurde zudem die chemische Reinigung mittels Zitronensäure und Natronlauge an einer Scalingschicht aus Calciumsulfat prozessbegleitend bewertet.
Basierend auf ImageJ und Matlab wurde eine Methode zur Bearbeitung der digitalen OCT-Datensätze entwickelt, die neben der Visualisierung vor allem eine sichere Quantifizierung des Scalings auf der Membranoberfläche ermöglichte. Gebildete Artefakte – hervorgerufen durch die Eigenschaften der Salzkristalle – wurden durch die PolyFIT Methode kompensiert und die Fehlerrate deutlich reduziert. Neu entwickelte Scalingparameter ermöglichten zudem eine objektive morphologische Bewertung des Membranzustandes und können als membranbasierte Prozessleitparameter eingesetzt werden.
Die gezielte Veränderung der Temperatur hatte einen maßgeblichen Einfluss auf die Bildung von Calcit-Deckschichten. Eine erhöhte Prozesstemperatur setzte die Löslichkeit der Ionen herab und führte damit zu einer massiven und schnellen Bildung von großen Kristallen auf der Membranoberfläche. Die schrittweise Erhöhung des Permeatstroms J_P (temperaturgekoppelt) führte ebenfalls zur verstärkten Bildung von Calcit-Scaling. Dies wurde durch das vermehrte Auftreten von temporären lokalen Superkonzentrationen bei hohem J_P erklärt. Die Variation der Konfiguration von Direct Contact zu Air Gap hatte keinen Einfluss auf das Wachstum der anorganischen Deckschicht. Durch die Änderung der Wassermatrix bildeten sich ähnliche Scalingschichten aus Calcit und Magensiumcalcit. Beide führten zur identischen Reduktion des Permeatstroms, die durch unterschiedliche Bedeckungsgrade in Kombination mit signifikant verschiedenen Kristallmorphologien hervorgerufen wurde. Die alleinige Detektion von J_P lieferte damit nur unzureichend genaue Informationen, die nur eingeschränkt für die Interpretation von Scaling genutzt werden konnten. Die Bestimmung der Scalingparameter verdeutlichte die Unterschiede hingegen klar und lieferte neben der Wachstumsgeschwindigkeit auch Informationen über die Morphologie der Kristalle.
Die Menge an chemisch abgereinigtem Calciumsulfat wurde in situ untersucht und anhand der Scalingparameter quantifiziert. Neben dem idealen Zeitpunkt zur Reinigung konnten damit auch die Reinigungsdauer und die Effektivität der verwendeten Chemikalien bestimmt werden. Dabei zeigte Zitronensäure eine verbesserte Reinigungskinetik gegenüber Natronlauge.
Die in der vorliegenden Arbeit entwickelte Methode stellt damit ein Werkzeug zur ganzheitlichen Optimierung der Membrandestillation in Bezug auf die Bildung von Scaling dar und liefert durch die nicht invasive Anwendung Informationen zur morphologischen Entwicklung der Deckschicht
Spread of antimicrobial resistance genes via pig manure from organic and conventional farms in the presence or absence of antibiotic use
Methods and results AMR-genes-namely tet(A), tet(B), tet(M), sul2 and qacE/qacEΔ1 (potentially associated with multiresistance) were quantified by qPCR. Antimicrobial use during the study period was qualitatively assessed from official records in a binary mode (yes/no). Median concentrations were between 6.44 log copy-equivalents/g for tet(A) and 7.85 for tet(M) in organic liquid manure, and between 7.48 for tet(A) and 8.3 for sul2 in organic farmyard manure. In conventional manure, median concentrations were 6.67 log copy-equivalents/g for sul2, 6.89 for tet(A), 6.77 for tet(B) and 8.36 for tet(M). Integron-associated qac-genes reached median concentrations of 7.06 log copy-equivalents/g in organic liquid manure, 7.13 in conventional manure and 8.18 in organic farmyard manure. The use of tetracyclines or sulfonamides increased concentrations of tet(A) and tet(M), or of sul2, respectively. Comparing farms that did not apply tetracyclines during the study, the relative abundance of tet(A) and tet(M) was still higher for conventional piggeries than for organic ones. Conclusions Relative abundances of AMR genes were higher in conventional farms, compared to organic ones. Antibiotic use was linked to the relative abundance of AMR-genes. However, due to the bacterial load, absolute concentrations of AMR-genes were comparable between fertilizers of organic and conventional farms. Significance and impact of study To our knowledge, this is the first absolute quantification of AMR-genes in manure from organic farms. Our study underlines the importance of long-term reduction in the use of antimicrobial agents in order to minimize antibiotic resistance
Good bot vs. bad bot: Opportunities and consequences of using automated software in corporate communications
The paper attempts to lay a foundation for research on the use of bots in corporate communications. The first step is to identify opportunities and challenges that may offer starting points for future regulations. In this research project, expert interviews were conducted in the form of guideline-based telephone interviews. A total of ten experts from the scientific community and experts from the practical field were interviewed. Following this, a qualitative-reductive content analysis was conducted with the aim of building categories and hypotheses based on them. The results show that experts from the scientific community and practical field clearly see advantages for corporate communications, but also highlight hurdles and ethical challenges that are currently seen as a major barrier to the use of bots. In this context, experts mention, among other things, the assumption of structured routine tasks, ensuring efficiency and quality in corporate communications, cost efficiency and relieving employees. On the other hand, weaknesses, like the lack of transparency, data protection and loss of control arise. Results clearly show that the ethical perspective has to be taken into account. In this context, data protection, the question of responsibility and possible manipulation intentions are particularly worth mentioning
Physical Self-Concept and Physical Activity in Children with Congenital Heart Defects—Can We Point Out Differences to Healthy Children to Promote Physical Activity?
Objective: Children with congenital heart defects (CHD) are at high risk for cardiovascular disease in addition to their congenital disease, so it is important to motivate this group of patients to live a physically active lifestyle. A potential influencing determinant of younger children’s physical performance is the physical self-concept. The objective of the present study was first to evaluate the correlation between the physical self-concept (PSC) and the participation in physical activities (PA) of a representative group of children with congenital heart disease (CHD), and second to point out differences in comparison to their healthy peer group. Methods: Using the database of PA of the S-BAHn-Study we focused on physical self-concept assessed by the German version of the Physical Self-Description Questionnaire. We compare the obtained data of children with CHD to a representative age-matched sample of 3.385 participants of the Motorik Modul Study. Results: N = 1.198 complete datasets could be included in the analyses. The mean age of patients was 11.6 ± 3.1 years. For the total cohort of patients with CHD and the reference group, PA correlated significantly with a positive PSC (p 0.24). Conclusions: According to this representative survey, there is a clear relation between PA and PSC in the cohort of healthy children and the group of children with CHD throughout the severity of their heart defects. Although PSC did not differ in patients with simple CHD and their healthy peer group, PA was significantly reduced. This gap invites us to reflect on how we could break new ground to promote a physically active lifestyle in children with CHD regardless of the severity of their cardiac defects
Viewpoints. 75 Sides to Freie Universität Berlin
Das Buch mit 75 Illustrationen und Kurztexten ist eine Reise durch die Geschichte und Welt der Freien Universität Berlin und entstand im April 2023 anlässlich ihres 75-jährigen Gründungsjubiläums. Die Bilder zeigen, ohne Anspruch auf Vollständigkeit, mit Augenzwinkern, eine vernetzte und internationale Universität, die sich seit ihren Anfängen und fortwährend ihren Leitwerten Freiheit, Gerechtigkeit und Wahrheit verpflichtet fühlt und zu einem bedeutenden Teil der Stadt und des Wissenschaftsraums Berlin geworden ist. Aspekte ihrer Geschichte und Gegenwart wurden künstlerisch interpretiert von Yves Haltner, einem Schweizer Illustrator und Grafiker, der in Berlin lebt und arbeitet.The book containing 75 illustrations and short texts is a journey through the history and world of Freie Universität Berlin. It was created in April 2023 to mark the occasion of the 75th anniversary of the university’s founding. With a hint of irony and pointed fragmentary playfulness, the images depict a connected, international university deeply committed to its core values: freedom, justice, truth. The university has become an important part of Berlin as a city and research hub. Various aspects of the past and present of the university were artistically interpreted by Yves Haltner, a Swiss illustrator and graphic designer who lives and works in Berlin
The role of risk communication in public health interventions. An analysis of risk communication for a community quarantine in Germany to curb the SARS-CoV-2 pandemic
Background: Separating ill or possibly infectious people from their healthy community is one of the core principles of non-pharmaceutical interventions. However, there is scarce evidence on how to successfully implement quarantine orders. We investigated a community quarantine for an entire village in Germany (Neustadt am Rennsteig, March 2020) with the aim of better understanding the successful implementation of quarantine measures. Methods: This cross-sectional survey was conducted in Neustadt am Rennsteig six weeks after the end of a 14-day mandatory community quarantine. The sample size consisted of 562 adults (64% of the community), and the response rate was 295 adults, or 52% (33% of the community). Findings: National television was reported as the most important channel of information. Contact with local authorities was very limited, and partners or spouses played a more important role in sharing information. Generally, the self-reported information level was judged to be good (211/289 [73.0%]). The majority of participants (212/289 [73.4%]) approved of the quarantine, and the reported compliance was 217/289 (75.1%). A self-reported higher level of concern as well as a higher level of information correlated positively with both a greater acceptance of quarantine and self-reported compliant behaviour. Interpretation: The community quarantine presented a rare opportunity to investigate a public health intervention for an entire community. In order to improve the implementation of public health interventions, public health risk communication activities should be intensified to increase both the information level (potentially leading to better compliance with community quarantine) and the communication level (to facilitate rapport and trust between public health authorities and their communities). © 2021 Scholz et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited
Perforin deficiency attenuates collagen-induced arthritis
Collagen-induced arthritis (CIA), an approved animal model for rheumatoid arthritis, is thought to be a T cell-dependent disease. There is evidence that CD8(+ )T cells are a major subset controlling the pathogenesis of CIA. They probably contribute to certain features of disease, namely tissue destruction and synovial hyperplasia. In this study we examined the role of perforin (pfp), a key molecule of the cytotoxic death pathway that is expressed mainly in CD8(+ )T cells, for the pathogenesis of CIA. We generated DBA/1J mice suffering from mutations of the pfp molecule, DBA/1J-pfp(-/-), and studied their susceptibility to arthritis. As a result, pfp-deficient mice showed a reduced incidence (DBA/1J-pfp(+/+), 64%; DBA/1J-pfp(-/-), 54%), a slightly delayed onset (onset of disease: DBA/1J-pfp(+/+), 53 ± 3.6; DBA/1J-pfp(-/-), 59 ± 4.9 (mean ± SEM), and milder form of the disease (maximum disease score: DBA/1J-pfp(+/+), 7.3 ± 1.1; DBA/1J-pfp(-/-), 3.4 ± 1.4 (mean ± SEM); P < 0.05). Concomitantly, peripheral T cell proliferation in response to the specific antigen bovine collagen II was increased in pfp(-/- )mice compared with pfp(+/+ )mice, arguing for an impaired killing of autoreactive T cells caused by pfp deficiency. Thus, pfp-mediated cytotoxicity is involved in the initiation of tissue damage in arthritis, but pfp-independent cytotoxic death pathways might also contribute to CIA
Influence of the autotaxin-lysophosphatidic acid axis on cellular function and cytokine expression in different breast cancer cell lines
Previous studies provide high evidence that autotaxin (ATX)-lysophosphatidic acid (LPA) signaling through LPA receptors (LPAR) plays an important role in breast cancer initiation, progression, and invasion. However, its specific role in different breast cancer cell lines remains to be fully elucidated to offer improvements in targeted therapies. Within this study, we analyzed in vitro the effect of LPA 18:1 and the LPAR1, LPAR3 (and LPAR2) inhibitor Ki16425 on cellular functions of different human breast cancer cell lines (MDA-MB-231, MDA-MB-468, MCF-7, BT-474, SKBR-3) and the human breast epithelial cell line MCF-10A, as well as Interleukin 8 (IL-8), Interleukin 6 (IL-6) and tumor necrosis factor (TNF)-alpha cytokine secretion after LPA-incubation. ATX-LPA signaling showed a dose-dependent stimulatory effect especially on cellular functions of triple-negative and luminal A breast cancer cell lines. Ki16425 inhibited the LPA-induced stimulation of triple-negative breast cancer and luminal A cell lines in variable intensity depending on the functional assay, indicating the interplay of different LPAR in those assays. IL-8, IL-6 and TNF-alpha secretion was induced by LPA in MDA-MB-468 cells. This study provides further evidence about the role of the ATX-LPA axis in different breast cancer cell lines and might contribute to identify subtypes suitable for a future targeted therapy of the ATX-LPA axis
Immunoprecipitation methods impact the peptide repertoire in immunopeptidomics
IntroductionMass spectrometry-based immunopeptidomics is the only unbiased method to identify naturally presented HLA ligands, which is an indispensable prerequisite for characterizing novel tumor antigens for immunotherapeutic approaches. In recent years, improvements based on devices and methodology have been made to optimize sensitivity and throughput in immunopeptidomics. However, developments in ligand isolation, mass spectrometric analysis, and subsequent data processing can have a marked impact on the quality and quantity of immunopeptidomics data.MethodsIn this work, we compared the immunopeptidome composition in terms of peptide yields, spectra quality, hydrophobicity, retention time, and immunogenicity of two established immunoprecipitation methods (column-based and 96-well-based) using cell lines as well as primary solid and hematological tumor samples.ResultsAlthough, we identified comparable overall peptide yields, large proportions of method-exclusive peptides were detected with significantly higher hydrophobicity for the column-based method with potential implications for the identification of immunogenic tumor antigens. We showed that column preparation does not lose hydrophilic peptides in the hydrophilic washing step. In contrast, an additional 50% acetonitrile elution could partially regain lost hydrophobic peptides during 96-well preparation, suggesting a reduction of the bias towards the column-based method but not completely equalizing it.DiscussionTogether, this work showed how different immunoprecipitation methods and their adaptions can impact the peptide repertoire of immunopeptidomic analysis and therefore the identification of potential tumor-associated antigens
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