Comparative Study of Different Methods for Soot Sensing and Filter Monitoring in Diesel Exhausts

Due to increasingly tighter emission limits for diesel and gasoline engines, especially concerning particulate matter emissions, particulate filters are becoming indispensable devices for exhaust gas after treatment. Thereby, for an efficient engine and filter control strategy and a cost-efficient filter design, reliable technologies to determine the soot load of the filters and to measure particulate matter concentrations in the exhaust gas during vehicle operation are highly needed. In this study, different approaches for soot sensing are compared. Measurements were conducted on a dynamometer diesel engine test bench with a diesel particulate filter (DPF). The DPF was monitored by a relatively new microwave-based approach. Simultaneously, a resistive type soot sensor and a Pegasor soot sensing device as a reference system measured the soot concentration exhaust upstream of the DPF. By changing engine parameters, different engine out soot emission rates were set. It was found that the microwave-based signal may not only indicate directly the filter loading, but by a time derivative, the engine out soot emission rate can be deduced. Furthermore, by integrating the measured particulate mass in the exhaust, the soot load of the filter can be determined. In summary, all systems coincide well within certain boundaries and the filter itself can act as a soot sensor

The Role of Cyclooxygenase-1 and -2 in Sevoflurane-Induced Postconditioning Against Myocardial Infarction

Cyclooxygenase (COX)-2 mediates ischemic pre- and postconditioning as well as anesthetic-induced preconditioning. However, the role of COX-1 and -2 in anesthetic-induced postconditioning has not been investigated. We evaluated the role of COX-1 and -2 in sevoflurane-induced postconditioning in vivo. Pentobarbital-anaesthetized male C57BL/6 mice were subjected to 45 minutes of coronary artery occlusion and 3 hours of reperfusion. Animals received either no intervention, the vehicle dimethyl sulfoxide (DMSO, 10 µL/g intraperitoneally), acetylsalicylic acid (ASA, 5 µg/g intraperitoneally), the selective COX-1 inhibitor SC-560 (10 µg/g intraperitoneally), or the selective COX-2 inhibitor NS-398 (5 µg/g intraperitoneally). 1.0 MAC (minimum alveolar concentration) sevoflurane was administered for 18 minutes during early reperfusion either alone or in combination with ASA, SC-560, and NS-398. Infarct size was determined with triphenyltetrazolium chloride. Statistical analysis was performed using 1-way and 2-way analyses of variance with post hoc Duncan testing. The infarct size in the control group was 44% ± 9%. DMSO (42% ± 7%), ASA (36% ± 6%), and NS-398 (44% ± 18%) had no effect on infarct size. Sevoflurane (17% ± 4%; P < .05) and SC-560 (26% ± 10%; P < .05) significantly reduced the infarct size compared with control condition. Sevoflurane-induced postconditioning was not abolished by ASA (16% ± 5%) and SC-560 (22% ± 4%). NS-398 abolished sevoflurane-induced postconditioning (33% ± 14%). It was concluded that sevoflurane induces postconditioning in mice. Inhibition of COX-1 elicits a myocardial infarct size reduction and does not abolish sevoflurane-induced postconditioning. Blockade of COX-2 abolishes sevoflurane-induced postconditioning. These results indicate that sevoflurane-induced postconditioning is mediated by COX-2

Therapeutic Anticoagulation with Argatroban and Heparins Reduces Granulocyte Migration: Possible Impact on ECLS-Therapy?

Introduction. Anticoagulants such as argatroban and heparins (low-molecular-weight and unfractionated) play an immense role in preventing thromboembolic complications in clinical practice. Nevertheless, they can also have a negative effect on the immune system. This study is aimed at investigating the influence of these substances on polymorphonuclear neutrophils (PMNs), whose nonspecific defense mechanisms can promote thrombogenesis. Methods. Blood samples from 30 healthy volunteers were investigated, whereby PMNs were isolated by density gradient centrifugation and incubated with 0.8 mu g/mL of argatroban, 1.0 U/mL of low-molecular-weight heparin (LMWH), 1.0 U/mL of unfractionated heparin (UFH), or without drug (control). A collagen-cell mixture was prepared and filled into 3D mu-slide chemotaxis chambers (IBIDI (R) GmbH, Germany). Stimulation was initiated by using a chemokine gradient of n-formyl-methionine-leucyl-phenylalanine (fMLP), and microscopic observation was conducted for 4.5 hours. The cells' track length and track straightness, as well as the number of attracted granulocytes, level of ROS (reactive oxygen species) production, and NET (neutrophil extracellular traps) formation, were analyzed and categorized into migration distances and time periods. Results. All three anticoagulants led to significantly reduced PMN track lengths, with UFH having the biggest impact. The number of tracks observed in the UFH group were significantly reduced compared to the control group. Additionally, the UFH group demonstrated a significantly lower track straightness compared to the control. ROS production and NET formation were unaffected. Conclusion. Our data provide evidence that anticoagulants have an inhibitory effect on the extent of PMN migration and chemotactic migration efficiency, thus indicating their potential immune-modulatory and prothrombotic effects

Characterisation of the cardiac function of the stress protein alpha-B-Crystallin in isolated murine papillary muscles

Eine familiäre Myopathie und Kardiomyopathie, der eine Missense-Mutation des alpha-B-Crystallin-Gens zugrunde liegt, weist auf eine wichtige Bedeutung des Stressproteins alpha-B-Crystallin im Herzen hin. Die chaperone-ähnlichen Eigenschaften von alpha-B-Crystallin und die unter kardialer Ischämie zu beobachtende schnelle Translokation vom Zytosol an das elastische Titin-Filamentsystem lassen eine protektive Rolle von alpha-B-Crystallin unter Stressbedingungen vermuten. Ziel der vorliegenden Arbeit war es, eine eventuelle kardioprotektive Funktion von alphaB-Crystallin durch die Charakterisierung alpha-B-Crystallin gendeletierter Mäuse nachzuweisen. Wir etablierten hierfür ein Versuchssystem zur Untersuchung der Kontraktilität isolierter Papillarmuskeln im Organbad. Im Rahmen des Aufbaus unseres Versuchssystems untersuchten wir zunächst den Einfluss der Ca2+-Konzentration, der Temperatur und der Kontraktionsbedingungen (Auxotonie vs. Isometrie) auf die Kraft-Frequenz-Beziehung von murinem Myokard. Wir konnten zeigen, dass die Kraft-Frequenz-Beziehung von Myokardpräparaten der Maus von den genannten Versuchsbedingungen abhängig ist. Bei niedrigen Ca2+-Konzentrationen und Temperaturen ([Ca2+] = 1,0 mM, Temp. = 27 °C) ist sie positiv, flacht bei zunehmender Ca2+-Konzentration und Temperatur ab und ist für [Ca2+] = 5,0 mM, Temp. = 37 °C negativ. Auxotone Kontraktionsbedingungen führen im Vergleich zu isometrischen bei gleichen Ca2+-Konzentrationen und Temperaturen zu einem flacheren Verlauf der Kraft-Frequenz-Beziehung. Unter annähernd physiologischen Bedingungen verläuft die Kraft-Frequenz-Beziehung des Mäuse-Myokards flach bis leicht positiv. Im Gegensatz zum Menschen scheinen somit bei der Maus für eine Steigerung des Herz-Zeit-Volumens andere Mechanismen als eine positive Kraft-Frequenz-Beziehung von Bedeutung zu sein. Hierbei ist insbesondere der Frank-Starling-Mechanismus und die sympathoadrenerge Innervation des Herzens zu erwähnen. Zur Charakterisierung der kardialen Funktion von alphaB-Crystallin untersuchten wir die Kontraktilität isolierter Papillarmuskeln von Wildtyp- und alpha-B-Crystallin gendeletierten Mäusen unter simulierter Ischämie (Glucose- und Sauerstoffentzug) und Reperfusion im Organbad. Unter Kontrollbedingungen zeigten sich zwischen wt- und alpha-B-/- Muskeln keine Unterschiede in der Zuckungskraft, der Geschwindigkeit der Kraftentwicklung und der Relaxationszeit. Die während der 20-minütigen simulierten Ischämie entwickelte Kontraktur setzte jedoch bei den alpha-B-/- Muskeln signifikant früher ein und verlief signifikant stärker als bei wt-Muskeln. Nach einer 60-minütigen Reperfusionsphase blieb die Kontraktur der alpha-B-/- Muskeln im Vergleich zu wt-Muskeln signifikant erhöht. Bezüglich Zuckungskraft, Geschwindigkeit der Kraftentwicklung und Relaxationszeit zeigten sich weder während noch nach simulierter Ischämie deutliche Unterschiede zwischen den Muskeln beider Mäusestämme. Diese Ergebnisse lassen darauf schließen, dass das Fehlen von alpha-B-Crystallin am Gesamtherz nicht zu einer Störung der systolischen Herzfunktion, sondern zu einer eingeschränkten myokardialen Relaxationsfähigkeit unter Ischämie und Reperfusion führen würde. Da alpha-B-Crystallin unter kardialer Ischämie an das elastische Titin-Filamentsystem bindet, könnten die elastischen Eigenschaften des Myokards unter Ischämie durch einen Mangel an alpha-B-Crystallin derart beeinträchtigt werden, dass es zu einer höheren Rigidität der Muskulatur kommt. Eine Funktion von alpha-B-Crystallin im Herzen ist somit möglicherweise die Aufrechterhaltung der elastischen Eigenschaften des Myokards unter kardialer Ischämie und Reperfusion.Missense mutations of the alpha-B-Crystallin gene have been shown to cause familial myopathy and cardiomyopathy suggesting an important role of the stress protein alpha-B-Crystallin in cardiac function. The aim of this study was to investigate if alpha-B-Crystallin may play a cardioprotective role during cardiac ischemia/reperfusion using alpha-B-Crystallin-deficient (alpha-B-/-) mice. For this purpose we established an ischemia/reperfusion model of isolated perfused murine papillary muscles and first investigated the influence of Ca2+, temperature and contraction type (auxotonic vs. isometric) on the force-frequency-relation (FFR) of murine myocardium defining optimal experimental conditions for isolated murine papillary muscle preparations. Under isometric conditions low Ca2+ (1.0 mM) and low temperature (27°C) lead to a positive FFR, while at high Ca2+ and temperature (5,0 mM, 37°C) the FFR turned negative. Auxotonic contractions resulted in flattening of the FFR compared to isometric concentrations. Thus, under conditions mimicking the physiological situation best ([Ca2+] = 1,5 mM, 32°C, auxotony) the FFR of murine heart is flat indicating that in contrast to the human heart in the mouse heart in vivo a positive inotropic effect by increasing heart frequency does not contribute significantly to increase cardiac output. To characterise cardiac function of alpha-B-Crystallin papillary muscles from alpha-B-/- and wildtype mice were exposed to 20 min of simulated ischemia (withdrawal of glucose and oxygen) and 60 min of reperfusion. Under physiological conditions no differences in contractility of alpha-B-/- and wildtype mice were observed. However, during simulated ischemia the development of ischemic contracture started earlier and reached a significant higher value in alpha-B-/- than in wildtype muscles. The recovery of the contracture during simulated reperfusion was also significantly attenuated. Interestingly, twitch force was neither during ischemia nor during the reperfusion period significantly altered. This suggests that during ischemia alpha-B-Crystallin may rather serve to protect cardiac relaxation (diastolic function) than contraction itself. The molecular mechanisms underlying this pronounced pathological behaviour remain to be determined. Since alpha-B-Crystallin is known to bind to the elastic titin filament system during ischemia we propose that increased ischemia-induced cardiac muscle stiffness in alpha-B-/- mice result from reduced elastic properties of titin in the absence of alpha-B-Crystallin. Thus, one possible function of alpha-B-Crystallin in the heart might be to preserve myofibrillar elastic properties during ischemia/reperfusion

Als Die weyland Hoch-Edelgebohrne Frau, Frau Susanna Elisabetha, gebohrne Götzin, Des Hoch-Edelgebohrnen Herrn, Herrn D. Christoph Heinrich Freieslebens, Sr. Hoch-Fürstl. Durchl. zu Sachsen-Gotha ... Cammer- und Berg-Raths, Hertzlich geliebteste Frau Eheliebste, Den 7. Septembr. 1726. dieses Zeitliche mit dem Ewigen verwechselte, Und darauf ... Den 22. ejusd. war der XIV. Sonntag nach Trinit. ... in der St. Barthol. Kirche Eine .... Gedächtniß-Predigt gehalten wurde, Wollte ... Seine hertzliche Compassion ... abstatten, Das allhiesige Geistliche Stadt-Ministerium

Enth. 7 Gedichte der BeiträgerVorlageform des Erscheinungsvermerks: Altenburg, gedruckt bey Joh. Ludwig Richtern, F. S. Hof-Buchdruckern

Den gestärckten Glauben Der weyland Wohl-Edlen, Groß- Ehr- und Tugend-belobten Frauen Johannen Dorotheen Langhußin, gebohrner Franckin, Des Hoch-Ehrwürdigen, Groß-Achtbaren und Wohlgelahrten Herrn Christian Dan. Langenhußens Wohlverordneten Diaconi beym Stadt-Ministerio hiesiger Fürstl. Residentz-Stadt Altenburg, Jm Leben lieb-gewesener Fr. Ehe-Liebsten, Als dieselbe den 10. Octobr. 1721. ... entschlaffen, Und Deren entseelter Cörper den 14. ejusd. mit öffentlichen Leich-Ceremonien ... beerdiget wurde, Wolte in der dabey gehaltenen Leichen-Predigt über die Worte II. Timoth. I. vers. 12. vorstellen D. Carl Andreas Redel, Fürstl. Sächß. Consistorial-Rath, und General-Superintendens zu Altenburg

Leichenpredigt auf Johanna Dorothea Langhuß, geb. Franck, + 10. Okt. 1721Die Vorlage enthält insgesamt 2 WerkeVorlageform des Erscheinungsvermerks: Altenburg, gedruckt bey Johann Ludwig Richtern, Fürstl. Sächß. Hof-Buchdruckern