Partial purification and characterization of a jasmonic acid conjugate cleaving amidohydrolase from the fungus Botryodiplodia theobromae

AbstractA protein preparation from the mycelium of the tropical pathogenic fungus Botryodiplodia theobromae revealed a novel peptidase activity. This enzyme was capable of cleaving conjugates of jasmonic acid with α-amino acids. The protein was enriched 108-fold by gel filtration, ion exchange and hydrophobic interaction chromatography. The enzyme was found to be a glycoprotein with a molecular mass of about 107 kDa. The amidohydrolase seems to be very specific with regard to (−)-jasmonic acid and α-amino acids with (S)-configuration

SDRP JOURNAL OF BIOMEDICAL ENGINEERING 2016 Research Electrochemical characterization of vascular bare-metal stents. A novel approach modifying the mini-cell system

ABSTRACT: Electrochemical characterization of stents can be seen as a key to assessing their biocompatibility. The aim of the present study was to investigate the electrochemical properties of bare-metal stent surfaces. The minicell system (MCS) was modified to record open circuit potential (OCP), cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) on NiTi, FeCrNi and CoCr stents using 1%NaCl, PBS and serum. Surfaces were examined by scanning electron microscopy (SEM) and energy-dispersive X-ray microanalysis (EDX) before and after electrochemical testing. CV showed passivity breakdown of FeCrNi and CoCr in 1%NaCl. Corrosion properties were inhomogeneous. Several surfaces of FeCrNi showed progressive activation and passivity breakdown while pitting was detected by SEM. EDX showed a decrease in Fe, Cr and Ni and an excessive presence of Cl. Corrosion rates (vcorr) were partially significantly different between the examined materials and electrolytes (e.g. using 1%NaCl: vcorr[FeCrNi]=2.08x10 -2 ±1.14x10 -2 μm/y vs. [NiTi]=9.41x10 -3 ±1.87x10 -3 μm/y; p<0.001). EIS circuit diagrams indicated oxide films on passivated metal surfaces. The modified MCS is promising to assess the biocompatibility of stents via electrochemical analytics. Overall, the vcorr of all stents were below the required limit values

Bactericidal Efficacy of Cold Plasma at Different Depths of Infected Root Canals In Vitro

Objectives: Cold plasma (CP) has been shown to be effective even against multiresistant microorganisms. As previous investigations on the effect of CP in root canals showed promising results, the aim of the present study was to analyze the bactericidal efficacy of CP in different depths of infected dentin. Methods: 32 standardized root canals of human mandibular premolars were infected with Enterococcus faecalis and incubated for one week. Specimens were randomly selected for one of four disinfection methods: control (5mL NaCl), 5mL chlorhexidine (CHX), CP alone (CP), and a combination of 5mL CHX and cold plasma (CHX+CP). CHX was ultrasonically activated for 30s, while cold plasma was used for 60s in the root canals. Dentin samples at depths of 300, 500 and 800 µm were obtained and diluted serially. Colony forming units (CFUs) were counted on agar plates after 24h of incubation. Results: The highest overall logarithmic reduction factors (RF) were obtained from CHX+CP (log RF 3.56 p<0.01; Mann-Whitney U test), followed by CP (log RF 3.27 p<0.01) and CHX alone (log RF 2.65 p<0.01) related to the control. All disinfection methods showed significantly lower CFU counts compared to the control group in 300 µm and 800 µm (both p<0.01, Kruskal-Wallis test). Discussion: The adjuvant use of CP might be beneficial in highly infected root canals to improved disinfection. However, the disinfection effect against Enterococcus faecalis of CP is comparable to ultrasonically activated CHX

Erinnerte Macht. Antike Herrschergräber in transkultureller Perspektive

Zu den Leitformen der alten Reiche Ostasiens und der westlichen Antike gehören exponierte Gräber der führenden Persönlichkeiten. Die Beiträge untersuchen, wie die Grabanlagen die Erinnerung an den Toten formten, zugleich die Wertvorstellungen ihrer Zeit spiegeln und zur Stabilisierung der geltenden Ordnung beitrugen. Dabei interessiert die Funktion der Gräber als Mittel der Selbstdarstellung und als Selbstbeschreibung des Herrschers. Aufschluss geben vor allem jene Monumente, die vom Regenten selber zu Lebzeiten geplant und errichtet worden sind. Ein zweiter Aspekt ist die Bedeutung des Grabs als Manifestation von Vorstellungen über Herrschaft. So kann die Wahl der Bauform den Bezug auf frühere Denkmäler herstellen und damit den Verstorbenen in eine bestimmte Tradition stellen oder aber grundlegende neue Formen finden und so seine besondere Position betonen. Ebenso untersucht wird der Einfluss der Gräber auf das Bild der Nachwelt von der Person des Herrschers und ihre Instrumentalisierung durch die Nachfolger zur Stabilisierung der eigenen Macht

Time-dependent screening of a positive charge distribution in metals: Excitons on an ultra-short time scale

Experiments determining the lifetime of excited electrons in crystalline copper reveal states which cannot be interpreted as Bloch states [S. Ogawa {\it et al.}, Phys. Rev. B {\bf 55}, 10869 (1997)]. In this article we propose a model which explains these states as transient excitonic states in metals. The physical background of transient excitons is the finite time a system needs to react to an external perturbation, in other words, the time which is needed to build up a polarization cloud. This process can be probed with modern ultra-short laser pulses. We calculate the time-dependent density-response function within the jellium model and for real Cu. From this knowledge it is possible within linear response theory to calculate the time needed to screen a positive charge distribution and -- on top of this -- to determine excitonic binding energies. Our results lead to the interpretation of the experimentally detected states as transient excitonic states.Comment: 24 pages, 9 figures, to appear in Phys. Rev. B, Nov. 15, 2000, issue 2

Cyclic stretch increases splicing noise rate in cultured human fibroblasts

BACKGROUND: Mechanical forces are known to alter the expression of genes, but it has so far not been reported whether they may influence the fidelity of nucleus-based processes. One experimental approach permitting to address this question is the application of cyclic stretch to cultured human fibroblasts. As a marker for the precision of nucleus-based processes, the number of errors that occur during co-transcriptional splicing can then be measured. This so-called splicing noise is found at low frequency in pre-mRNA splicing. FINDINGS: The amount of splicing noise was measured by RT-qPCR of seven exon skips from the test genes AATF, MAP3K11, NF1, PCGF2, POLR2A and RABAC1. In cells treated by altered uniaxial cyclic stretching for 18 h, a uniform and significant increase of splicing noise was found for all detectable exon skips. CONCLUSION: Our data demonstrate that application of cyclic stretch to cultured fibroblasts correlates with a reduced transcriptional fidelity caused by increasing splicing noise

Influence of perpendicular magnetic fields on the domain structure of permalloy microstructures grown on thin membranes

Unlike the broadly studied influence of the in-plane magnetic fields on magnetic domain structures in thin-film elements, not much is known to date, on the changes of the domain structure driven by external magnetic fields applied perpendicular to the plane. Using high-resolution transmission electron microscopy studies combined with micromagnetic modeling, we investigated the effect of static, strong perpendicular fields on square and disk-shaped mesoscopic permalloy elements with a vortex flux-closure magnetization structure. In the case of square elements, we discovered an unexpected, pronounced, and reversible bending of the 90° domain walls, which increases with the field strength and changes direction when the field direction is reversed. By means of micromagnetic simulations and atomic force microscopy studies, we demonstrate that this effect is connected with the minute curvatures of the sample surface. The slight curvature arises from surface tensions in the membrane on which the microstructures are fabricated

Caligula-Bildnisse vom Typus Fasanerie in Spanien. Ein archäologischer Beitrag zur Geschichte des Kaisers Caius

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Das Porträt des Miltiades: Zum Wandel des Feldherrnbildnisses im klassischen Athen

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