Oberflächen-Plasmon-Resonanz- spektroskopische Studie an verschiedenen Biosensoroberflächen. Charakterisierung von Protein-Peptid und Protein-Lipid Wechselwirkungen

Surface plasmon resonance spectroscopy (SPR spectroscopy) is a technique for the time-resolved measurement of interactions between macromolecules. For thesemeasurements, it is necessary to immobilize a binding partner on the surface of asensor chip. The measurements are recorded as sensorgrams. In the present study,different surfaces were tested. The biological model system for the investigation ofinteractions was the binding of calmodulin to a synthetic peptide which correspondsto the amino-acid sequence of the CaM binding site from the typed nitrogen oxidesynthase. For binding CaM to this peptide, NOS-I WT, the rate constants (k$_{a}$, k$_{d}$) andthe equilibrium constants (KD) were determined by different evaluation methods.The dissociation constants determined from the sensorgrams for the different sensorchip surfaces increased with rising immobilization density. An analysis of the rateconstants determined from the sensorgrams showed that especially k$_{a}$ decreasedsubstantially with increasing immobilization density. The sensorgrams on the differentsensor surfaces could no longer be explained by a monoexponential bond model athigh immobilization density. This was also reflected in the decreasing stoichiometryof peptide NOS-I WT for CaM at increasing immobilization density of the peptide. Thebest agreement with the literature values achieved on a dextran surface at very lowimmobilization density (< 5.8 fmol/mm$^{2}$) on peptide NOS-I WT (K$_{D}$ values of 0.8 - 3.9nM).Furthermore, sensor chips with hydrophobic surfaces were produced to build upheterobilayers or phospholipid bilayers. These sensor chips were used to investigatethe Ca$^{2+}$-dependent membrane association of the Ca$^{2+}$ binding protein recoverin. AnN-terminal myristoyl group anchors recoverin at high calcium concentrations in themembrane. Mutants of recoverin were examined, whose affinities for Ca2+ ions weremodified in comparison to the wild type. All forms of recoverin (native, recombinantlymyristoylated (WT), EF+4, EF-3, EF-2) show a bond to the hydrophobic sensor chipsurface in the presence of Ca$^{2+}$ ions, although with different affinities (EC$_{50}$: nativerecoverin = 18 $\mu$M; WT = 5 $\mu$M; EF+4 = 29 $\mu$M; EF-3 = 8 $\mu$M; EF-2 = 9 $\mu$M).Interestingly enough, it was also possible to detect a bond to the phospholipid layerin the absence of Ca$^{2+}$ which, however, occurred with a markedly lower amplitude

Measuring Competition in the U.S. Airline Industry Using the Rosse-Panzar Test and Cross-Sectional Regression Analyses

We employ the Rosse-Panzar test to assess market performance in selected airport-pairs originating from Atlanta. The Rosse-Panzar test stands in the tradition of the New Empirical Industrial Organization. It is based on the comparative statics of a reduced form revenue equation. Therefore, it is less powerful than structural models, but it offers the advantage of less stringent data requirements and reduces the risk of model misspecifications. The test statistic allows us in most airport-pairs to reject both conducts consistent with the Bertrand outcome, which is equivalent to perfect competition, and the collusive outcome, which is equivalent to joint profit-maximization. Rather, the test statistic suggests that behavior is consistent with a range of intermediate outcomes between the two extremes, including, but not limited to the Cournot oligopoly. In the second part of the paper, a cross-section pricing regression complements the Rosse-Panzar test. It shows that the presence of low-cost competition in an airport-pair reduces the average fare significantly.airlines; oligopoly; conduct; price-cost marginas; Lerner index; Rosse-Panzar test

Photochemische und biochemische Modifikation von Bakteriorhodopsin: Optische Datenspeicherung und Hybridbio-Materialien

Entwicklung und Evaluierung einer auf Bakteriorhodopsin (BR) basierenden photochromen Tampondruckfarbe. Untersuchungen an neuen langzeitstabilen Photoprodukten von BR und Entwicklung eines biologisch-optischen WORM Datenspeichers und einer Datenchiffriermethode. Etablierung von MS- und LC/MS/MS-Methoden zur Untersuchung von biochemisch-modifiziertem BR. Entwicklung einer universellen Methode zur reversiblen Anbindung von Bionanokomponenten an BR. Etablierung einer Methode für die gerichtete Selbstassemblierung von Purpurmembranfragmenten auf Template-Stripped-Gold-Substraten

QCD's equation of state from Dyson-Schwinger equations

In this contribution, we summarize a truncation-independent method to compute the equation of state within nonperturbative functional approaches. After demonstrating its viability, the method is applied to solutions obtained from a set of truncated Dyson-Schwinger equations for the quark and gluon propagators of (2+1)-flavor QCD to obtain thermodynamic quantities across the phase diagram of strong-interaction matter.Comment: 6 pages, 2 figures; contribution to the proceedings of the FAIR next generation scientists workshop (FAIRNESS), 7th edition, 23-27 May 2022, Paralia (Pieria), Greec

Low cycle fatigue testing in high pressure gaseous hydrogen using tubular specimens

Please click Additional Files below to see the full abstrac

Outcome differences between PARAMEDIC2 and the German Resuscitation Registry: a secondary analysis of a randomized controlled trial compared with registry data.

BACKGROUND AND IMPORTANCE There has been much discussion of the results of the PARAMEDIC2 trial, as resuscitation outcome rates are considerably lower in this trial than in country-level registries on out-of-hospital cardiac arrest (OHCA). Here, we developed a statistical framework to investigate this gap and to examine possible sources for observed discrepancies in outcome rates. DESIGN Summary data from the PARAMEDIC2 trial were used as available in the publication of this study. We developed a modelling framework based on logistic regression to compare data from this randomized controlled trial and registry data from the German Resuscitation Registry (GRR), where we considered 26 019 patients treated with epinephrine for OHCA in the GRR. To account and adjust for differences in patient characteristics and baseline variables predictive for outcomes after OHCA between the GRR cohort and the PARAMEDIC2 study sample, we included all available variables determined at the arrival of EMS personnel in the modelling framework: age, sex, initial cardiac rhythm, cause of cardiac arrest, witness of cardiac arrest, CPR performed by a bystander, and the interval between emergency call and arrival of the ambulance at the scene (baseline model). In order to find possible explanations for the discrepancies in outcome between PARAMEDIC2 and GRR, in a second (baseline plus treatment) model, we additionally included all available variables related to the interventions of the EMS personnel (type of airway management, type of vascular access, and time to administration of epinephrine). MAIN RESULTS A patient cohort with baseline variables as in the PARAMEDIC2 trial would have survived to hospital discharge in 7.7% and survived with favourable neurological outcome in 5.0% in an EMS and health care system as in Germany, compared with 3.2 and 2.2%, respectively, in the Epinephrine group of the trial. Adding treatment-related variables to our logistic regression model, the rate of survival to discharge would decrease from 7.7 (for baseline variables only) to 5.6% and the rate of survival with favourable neurological outcome from 5.0 to 3.4%. CONCLUSION Our framework helps in the medical interpretation of the PARAMEDIC2 trial and the transferability of the trial's results for other EMS systems. Significantly higher rates of survival and favourable neurological outcome than reported in this trial could be possible in other EMS and health care systems

Initial joint stability affects the outcome after conservative treatment of simple elbow dislocations: a retrospective study

Background: Conservative treatment of simple elbow dislocations can lead to complications such as persisting pain and restricted joint mobility. The current aim was to identify patients with deteriorated outcome after conservative treatment and to investigate a possible association with initial joint (in)stability. Methods: Sixty-eight patients (mean age 37.1 ± 17.2 years) with simple elbow dislocations received conservative treatment. After closed reduction, joint stability was tested by varus and valgus stress under fluoroscopy. According to the findings under fluoroscopy, three different groups of instability could be identified: (1) slight instability (joint angulation <10°; n = 49), (2) moderate instability (angulation ≥10°; n = 19) and (3) gross instability. Patients with gross instability (re-dislocation under stability testing) were treated with primary surgical ligament repair and therefore excluded from this study. Additionally, MRIs and radiographs were analysed regarding warning signs of instability such as the drop sign and joint incongruence. Main outcome parameters were the Mayo Elbow Performance Score (MEPS), range of motion (ROM), complications and revision rates. Results: After 40.7 ± 20.4 months, the overall MEPS was excellent (94.2 ± 11.3) with a trend of slightly worse clinical results in group 2 (95.8 ± 9.0 vs. 90.0 ± 15.2 points; p = 0.154). In group 1, significantly more patients achieved an excellent result regarding the MEPS scoring system (77.6 vs. 52.6 %; p = 0.043) and elbow extension was significantly worse in group 2 (5.3 ± 9.9° vs. 1.4 ± 3.0°; p = 0.015). Seven treatment complications occurred in group 2 (36.8 %) compared with two in group 1 (4.1 %, p < 0.0001). Six patients (8.8 %) needed secondary surgery with an 8.4-fold higher risk for revision surgery in group 2 (p = 0.007). The presence of a positive drop sign or joint incongruence led to higher odds ratio (OR) for complications (OR = 15.9) and revision surgery (OR = 10.3). Conclusions: This study demonstrates that patients with moderate joint instability after simple elbow dislocation have a significantly worse clinical outcome, more complications and a higher need for secondary revision surgery following conservative treatment compared to patients with slight elbow instability