A gradient system with a wiggly energy and relaxed EDP-convergence

If gradient systems depend on a microstructure, we want to derive a macroscopic gradient structure describing the effective behavior of the microscopic effects. We introduce a notion of evolutionary Gamma-convergence that relates the microscopic energy and the microscopic dissipation potential with their macroscopic limits via Gamma-convergence. This new notion generalizes the concept of EDP-convergence, which was introduced in arXiv:1507.06322, and is called "relaxed EDP-convergence". Both notions are based on De Giorgi's energy-dissipation principle, however the special structure of the dissipation functional in terms of the primal and dual dissipation potential is, in general, not preserved under Gamma-convergence. By investigating the kinetic relation directly and using general forcings we still derive a unique macroscopic dissipation potential. The wiggly-energy model of James et al serves as a prototypical example where this nontrivial limit passage can be fully analyzed.Comment: 43 pages, 8 figure

Effective diffusion in thin structures via generalized gradient systems and EDP-convergence

The notion of Energy-Dissipation-Principle convergence (EDP-convergence) is used to derive effective evolution equations for gradient systems describing diffusion in a structure consisting of several thin layers in the limit of vanishing layer thickness. The thicknesses of the sublayers tend to zero with different rates and the diffusion coefficients scale suitably. The Fokker--Planck equation can be formulated as gradient-flow equation with respect to the logarithmic relative entropy of the system and a quadratic Wasserstein-type gradient structure. The EDP-convergence of the gradient system is shown by proving suitable asymptotic lower limits of the entropy and the total dissipation functional. The crucial point is that the limiting evolution is again described by a gradient system, however, now the dissipation potential is not longer quadratic but is given in terms of the hyperbolic cosine. The latter describes jump processes across the thin layers and is related to the Marcelin--de Donder kinetics

Expression of Recombinant Antibodies

Recombinant antibodies are highly specific detection probes in research, diagnostics, and have emerged over the last two decades as the fastest growing class of therapeutic proteins. Antibody generation has been dramatically accelerated by in vitro selection systems, particularly phage display. An increasing variety of recombinant production systems have been developed, ranging from Gram-negative and positive bacteria, yeasts and filamentous fungi, insect cell lines, mammalian cells to transgenic plants and animals. Currently, almost all therapeutic antibodies are still produced in mammalian cell lines in order to reduce the risk of immunogenicity due to altered, non-human glycosylation patterns. However, recent developments of glycosylation-engineered yeast, insect cell lines, and transgenic plants are promising to obtain antibodies with “human-like” post-translational modifications. Furthermore, smaller antibody fragments including bispecific antibodies without any glycosylation are successfully produced in bacteria and have advanced to clinical testing. The first therapeutic antibody products from a non-mammalian source can be expected in coming next years. In this review, we focus on current antibody production systems including their usability for different applications

A gradient system with a wiggly energy and relaxed EDP-convergence

If gradient systems depend on a microstructure, we want to derive a macroscopic gradient structure describing the effective behavior of the microscopic system. We introduce a notion of evolutionary Gamma-convergence that relates the microscopic energy and the microscopic dissipation potential with their macroscopic limits via Gamma-convergence. We call this notion relaxed EDP-convergence since the special structure of the dissipation functional may not be preserved under Gamma-convergence. However, by investigating the kinetic relation we derive the macroscopic dissipation potential

LDL-Carbamylierung als Mechanismus endothelialer Dysfunktion bei Patienten mit chronischer Nierenerkrankung

1.1 cLDL induziert endotheliale Dysfunktion bei Patienten mit chronischer Nierenerkrankung (CKD) Erhöhte LDL-Cholesterinspiegel sind insbesondere auch bei Patienten mit chronischer Nierenerkrankung wesentlich mit Atherosklerose und dem Auftreten von Gefäßkomplikationen vergesellschaftet. Vermehrt werden bei diesen Patienten Serumproteine posttranslational carbamyliert. Die Carbamylierung von Lipoproteinen kann die Schaumzellenbildung und endotheliale Dysfunktion begünstigen, eine mechanistische Bestätigung dieser Hypothese wurde bislang nicht erbracht. In dieser Studie wurden die endothelialen Effekte carbamylierten LDLs untersucht. Zunächst wurde LDL aus dem Serum gesunder Probanden isoliert und anschließend ex vivo carbamyliert. ESR-spektroskopisch zeigte sich eine gesteigerte ROS- und verminderte NO-Produktion nach Inkubation von murinen Aortenringen sowie in humanen aortalen Endothelzellen (HAEC) nach Inkubation mit carbamyliertem LDL (cLDL). Western Blot-Analysen ergaben einen durch cLDL hervorgerufenen aktivitätsmindernden Phosphorylierungszustand der endothelialen NO-Synthase (eNOS). Der als Entkopplung bezeichnete Zerfall der dimeren eNOS in Monomere, welche folglich ROS statt NO bilden, wurde ergänzend immunfluoreszenzmikroskopisch durch cLDL-abhängige S-Glutathionylierung aufgezeigt. Zudem konnte LOX-1 als Rezeptor identifiziert werden, der diese Effekte von cLDL auf HAEC vermittelt. C57BL/6J-Wildtypmäuse wiesen nach Injektion mit cLDL erhöhte ROSSpiegel in Vollblut und explantierten Aortenringen auf, wobei sich in Lox1 transgenen C57BL/6J- Mäusen mit endothelialer Überexpression von LOX-1 eine weitere deutliche Zunahme der Effektstärke objektivieren lies. Durch Inkubation mit spezifischen Inhibitoren wurden die Beteiligung der NADPH-Oxidase (Inhibition durch Captopril/ DPI) sowie p38 MAPK (Inhibition durch SB202190) an der LOX-1 Rezeptoraktivierung nachgeschalteten zellulären Signalkaskade bewiesen. Die klinische Relevanz der LDL-Carbamylierung verdeutlichte der Vergleich in vivo carbamylierter Lysin-Reste im LDL gesunder Probanden (kein Nachweis) und chronisch Nierenkranker (54 ± 4) mittels MALDI-ToF-Massenspektroskopie. Analog der ESR-spektroskopischen Studien mit ex vivo carbamyliertem LDL führte das aus dem Plasma von CKD-Patienten isolierte LDL zu einer signifikanten Reduktion der NO-Produktion in Zellkulturversuchen an HAEC. In einer klinischen Studie an Patienten mit CKD zeigte sich, dass hohe LDLCarbamyl- Lysinkonzentrationen mit höherer Mortalität und Inzidenz kardiovaskulärer Ereignisse assoziiert sind. Zusammenfassend zeigt diese Studie, dass cLDL bei chronisch Nierenkranken in klinisch relevantem Ausmaß endotheliale Dysfunktion über eine gesteigerte ROSProduktion und eine verminderte NO-Bioverfügbarkeit induziert. Auf molekularer Ebene werden hier nach LOX-1 Rezeptorbindung p38 MAPK und NADPH-Oxidase aktiviert sowie eNOS gehemmt und via S-Glutathionylierung entkoppelt. Diese Ergebnisse weisen auf einen wichtigen neuen Pathomechanismus für die Entstehung kardiovaskulärer Ereignisse bei Patienten mit Niereninsuffizienz hin. Zudem konnte cLDL als neuer Biomarker sowie therapeutischer Angriffspunkt identifiziert werden.1.2 cLDL induces endothelial dysfunction in patients with chronic kidney disease (CKD) Elevated levels of LDL-cholesterol are crucially involved in the pathogenesis of atherosclerosis and subsequent cardiovascular complications. This also applies to CKD-patients, whose serum proteins are increasingly subject to posttranslational carbamylation. Lipoprotein carbamylation is thought to promote foam cell formation and endothelial dysfunction but the underlying molecular mechanisms remained unclear. Here, we investigated the endothelial effects of carbamylated LDL. LDL was isolated from healthy donors’ serum and carbamylated ex vivo. ESR-spectroscopy showed an increased production of ROS and diminished release of NO in murine aortic rings and human aortic endothelial cells (HAEC) after incubation with cLDL. Western blot analyses revealed a cLDL-induced, activity-diminished phosphorylation state of eNOS, a key regulator of cellular redox state. In addition, uncoupling called disaggregation of dimeric eNOS into monomer units, which promotes the production of ROS instead of NO, was shown to be due to S-glutathionylation of eNOS. Moreover, LOX-1 was identified as the receptor mediating these adverse endothelial effects of cLDL. While C57BL/6J- wild type mice already featured increased levels of ROS in whole blood and explanted aortic rings after injection with cLDL, an even greater increase was observed in Lox1 transgenic C57BL/6J- mice exhibiting endothelial overexpression of LOX-1. Using specific inhibitors, further experiments demonstrated an involvement of NAPH-oxidase (inhibition by captopril/ DPI) and p38 MAPK (inhibition by SB202190) in the cellular downstream effects of LOX-1 receptor stimulation by cLDL. The clinical relevance of LDL carbamylation was proven by comparison of carbamylated lysine residues in LDL of healthy donors (none detectable) and CKD patients (54 ± 4) using MALDI-ToF mass spectrometry. Similar to LDL carbamylated ex vivo, incubation with LDL isolated from CKD patients’ plasma led to a significant reduction of basal NO-production in HAEC culture experiments. Notably, in a prospective clinical study of CKD patients, we could prove the clinical relevance of these experimental findings. Carbamyl-lysine levels in LDL were associated with increased all-cause mortality and cardiovascular event rate. In summary, cLDL induces endothelial dysfunction through increased production of ROS and diminished bioavailability of NO, in a clinically relevant dimension in CKD patients. LOX-1 receptor binding leads to activation of p38 MAPK and NADPHoxidase such as inhibition and uncoupling of eNOS by S-glutathionylation. These findings highlight on carbamylation of LDL as an important pathomechanism for CKD-associated accelerated cardiovascular disease. Moreover, cLDL was identified as a novel biomarker and potential therapeutic target

Teaching this class drives me nuts! - Examining the Person and Context Specificity of Teacher Emotions

Teachers' emotions are critically important for the quality of classroom instruction, and they are key components of teachers' psychological well-being. Past research has focused on individual differences between teachers, whereas within-teacher variation across contexts has rarely been considered. As such, the present research addresses the long-standing yet unresolved person-situation debate pertaining to the emotional experiences of teachers. In two diary studies (N = 135, 70% female, and N = 85, 28% female),we examined the role of person, academic subject, and group of students for teacher emotions;focusing on three of the most salient emotions found in teachers: enjoyment, anger, and anxiety. Findings from multi-level analysis confirmed the person specificity of enjoyment, anger, and, in particular, anxiety. In addition, underscoring the existence of within-teacher variability, findings supported that teachers' emotions considerably varied depending on the subject and group of students taught, particularly so for enjoyment and anger. Implications of the person and context specificity of teacher emotions are discussed in relation to assessments and intervention programs aiming to improve teachers' emotional lives in the classroom