63 research outputs found
On the characterization of the quenched regime in electrostatic precipitators
Unter Korona-Quenching versteht man die Verringerung der Stromaufnahme eines Elektroabscheiders unter dem Einfluss teilchengebundener Raumladung. Die theoretische Untersuchung dieses Betriebszustandes im Rohr-Draht-Elektroabscheider und die experimentelle Validierung der Vorhersagen sind Inhalt der Arbeit. Theoretisch wird das Korona-Quenching anhand unterschiedlich komplexer Modelle untersucht, die auf der Bilanzierung der teilchengetragenen Raumladung beruhen. Es zeigt sich dabei, dass der Elektroabscheider eine geometrieabhängige maximale Abscheiderate besitzt, die im gequenchten Zustand erreicht wird. Wegen der geringen Stromaufnahme erfolgt die Abscheidung hier besonders energieeffizient. Die vorgestellten Berechnungsmethoden erlauben eine Optimierung von Elektroabscheidern für hohe Teilchenkonzentrationen. Der Vergleich mit experimentellen Ergebnissen zeigt eine sehr gute Übereinstimmung mit den theoretischen Vorhersagen im jeweils beanspruchten Gültigkeitsbereich.The reduction of current uptake in electrostatic precipitators by particle attached space charge is known as Corona-Quenching. The focus of this work is on the theoretical description of the Corona-Quenching process in a tube-wire type electrostatic precipitator and the experimental validation of the findings. The basis of the description is a balance of particle attached space charge, whereby models of different complexity are discussed. It is found that there is a geometry dependent upper limit for the precipitation rate, which is achieved in the quenched state. Due to the very low current uptake precipitation of particle is highly energy efficient in this state. The presented calculation models allow designing and optimizing electrostatic precipitators for concentrated aerosols. The theoretical predictions are in good agreement with measurement results in the claimed ranges of validity
Distribution and second messenger coupling of four somatostatin receptor subtypes expressed in brain
AbstractThe mRNA distribution in the brain and the coupling to cellular effector systems of four somatostatin receptors (SSTR1-4) was studied. All four SRIF receptor subtypes were expressed in cortex and hippocampus. In addition, SSTR1 mRNA was relatively abundant in the spinal cord whereas SSTR2 mRNA was also present in the striatum. The SSTR3 gene was predominantly expressed in the olfactory bulb and in the cerebellum. Conflicting results about the effector coupling of SSTR1-3 have been published previously. We have stably expressed human SSTR1-4 in HEK 293 human embryonal kidney cells. Agonist binding to the receptor subtypes, including the recently cloned SSTR4, inhibited the formation of forskolin-induced cAMP. Is is concluded that, in an appropriate cellular environment, all four receptor subtypes can functionally couple to the inhibition of adenylyl cyclase
Diagnostic Specificity of Two Dengue Virus IgG ELISAs after Yellow Fever and Japanese Encephalitis Virus Vaccination
Dengue virus (DENV) antibody assays frequently cross-react with sera from individuals
who have been infected with or vaccinated against related flaviviruses. The goal of this study was to
determine the specificity of two DENV ELISAs with sera from individuals vaccinated against yellow
fever virus (YFV) and Japanese encephalitis virus (JEV). The Panbio and the Novatec Dengue IgG ELISAs
were tested with sera obtained 3–4 weeks or 0.5–6 years after YFV or JEV vaccination and the diagnostic
specificity of the assays was determined. As controls, the sera were tested using DENV, YFV, JEV, Zika
and West Nile virus neutralization assays. The diagnostic specificity of the Panbio and the Novatec
ELISA with sera from YFV-vaccinated subjects was 98.2% and 88.2%, respectively. Cross-reactions were
rare in the first 4 weeks despite high YFV-neutralizing antibody titers and were mostly found later. The
specificity of the Panbio and Novatec assays with sera from JEV-vaccinated individuals was 100% and
92.9%. Cross-reactions occurred in the early time period after vaccination. The measurement values of
the two ELISAs correlated strongly. Thus, the Panbio ELISA showed higher diagnostic specificity and
may be suitable for seroprevalence studies in areas with high disease prevalence
The value of hepatic resection in metastasic renal cancer in the era of Tyrosinkinase Inhibitor Therapy
Background: The value of liver-directed therapy (LDT) in patients with metastasic renal cell carcinoma (MRCC) is still an active field of research, particularly in the era of tyrosinkinase inhibitor (TKI) therapy. Methods: The records of 35 patients with MRCC undergoing LDT of metastasic liver lesions between 1992 and 2015 were retrospectively analyzed. Immediate postoperative TKI was given in a subgroup of patients after LDT for metastasic lesions. Uni- and multivariate models were applied to assess overall survival (OS), progression-free survival (PFS) and disease-free survival (DFS). Results: Following primary tumor (renal cell cancer) resection and LDT, respectively, median OS was better for a total of 16 patients (41 %) receiving immediate postoperative TKI with 151 and 98 months, when compared to patients without TKI therapy with 61 (p = 0.003) and 40 months (p = 0.032). Immediate postoperative TKI was associated with better median PFS (47 months versus 19 months; p = 0.023), whereas in DFS only a trend was observed (51 months versus 19 months; p = 0.110). Conclusions: LDT should be considered as a suitable additive tool in the era of TKI therapy of MRCC to the liver. In this context, postoperative TKI therapy seems to be associated with better OS and PFS, but not DFS
Context-aware genomic surveillance reveals hidden transmission of a carbapenemase-producing Klebsiella pneumoniae
Genomic surveillance can inform effective public health responses to pathogen outbreaks. However, integration of non-local data is rarely done. We investigate two large hospital outbreaks of a carbapenemase-carrying Klebsiella pneumoniae strain in Germany and show the value of contextual data. By screening about 10 000 genomes, over 400 000 metagenomes and two culture collections using in silico and in vitro methods, we identify a total of 415 closely related genomes reported in 28 studies. We identify the relationship between the two outbreaks through time-dated phylogeny, including their respective origin. One of the outbreaks presents extensive hidden transmission, with descendant isolates only identified in other studies. We then leverage the genome collection from this meta-analysis to identify genes under positive selection. We thereby identify an inner membrane transporter (ynjC) with a putative role in colistin resistance. Contextual data from other sources can thus enhance local genomic surveillance at multiple levels and should be integrated by default when available
Infektionsmedizinische und chirurgische Herausforderungen durch Carbapenem-resistente bakterielle Erreger bei der Versorgung Kriegsverletzter aus der Ukraine
Aufgrund von Hygienedefiziten und dem sehr breiten, kalkulierten Antibiotikaeinsatz bei zeit¬gleich offener Wundbehandlung in ukrainischen Militärkrankenhäusern ist das Risiko für schwerwiegende Wundinfektionen mit multiresis¬tenten Erregern (MRE) bei Übernahme ziviler Kriegsopfer hoch. Insofern kommt der Surveillance mit risikoadaptiertem Screening auf MRE, welches am Universitätsklinikum Leipzig seit 2012 durchgeführt wird, eine große Bedeutung zu. Es werden die Komplexität der Versorgung Kriegsverletzter aus der Ukraine sowie die damit einhergehenden Infektions- und Resistenzprobleme dargestellt und auf die Notwendigkeit eines interdisziplinären und -professionellen Managements hingewiesen.Peer Reviewe
Towards recombinantly produced milk proteins: Physicochemical and emulsifying properties of engineered whey protein beta-lactoglobulin variants
DFG, 273937032, SPP 1934: Dispersitäts-, Struktur- und Phasenänderungen von Proteinen und biologischen Agglomeraten in biotechnologischen ProzessenBMBF, 031B0222, Basistechnologie Nachwuchsgruppe "Multiskalige Modellierung und Modifikation von Multienzymkomplexen als Basistechnologie für zellfreie Reaktionskaskaden" (II
Prevalence of multidrug-resistant organisms in refugee patients, medical tourists and domestic patients admitted to a German university hospital
The value of hepatic resection in metastasic renal cancer in the Era of Tyrosinkinase Inhibitor Therapy
Antimicrobials: a global alliance for optimizing their rational use in intra-abdominal infections (AGORA)
- …