A novel active resonant turn-on snubber which feeds back the energy stored in the snubber inducto... more A novel active resonant turn-on snubber which feeds back the energy stored in the snubber inductor is analyzed. The energy is transformed by a resonant operating sequence. Due to the resonant transformation, most of the stored energy is fed back. The circuit is demonstrated with a 300 V, 100 A buck-boost converter.
More than 40 human infections with the zoonotic Borna disease virus 1 (BoDV-1) have been reported... more More than 40 human infections with the zoonotic Borna disease virus 1 (BoDV-1) have been reported to German health authorities from endemic regions in southern and eastern Germany. Diagnosis of a confirmed case is based on the detection of BoDV-1 RNA or BoDV-1 antigen. In parallel, serological assays such as ELISA, immunoblots, and indirect immunofluorescence are in use to detect the seroconversion of Borna virus-reactive IgG in serum or cerebrospinal fluid (CSF). As immunopathogenesis in BoDV-1 encephalitis appears to be driven by T cells, we addressed the question of whether an IFN-γ-based ELISpot may further corroborate the diagnosis. For three of seven BoDV-1-infected patients, peripheral blood mononuclear cells (PBMC) with sufficient quantity and viability were retrieved. For all three patients, counts in the range from 12 to 20 spot forming units (SFU) per 250,000 cells were detected upon the stimulation of PBMC with a peptide pool covering the nucleocapsid protein of BoDV-1. ...
The first perpetual university in Transylvania was founded rather late compared to European stand... more The first perpetual university in Transylvania was founded rather late compared to European standards, namely only in 1872 in Klausenburg (Cluj, Kolozsvár). Through the centuries, the social request for physicians was satisfied by the education of Transylvanian students at foreign universities and by the immigration of physicians from abroad. Concerning the period from 1180 to 1849, we know about 7145 Transylvanian students at more than 80 different universities of the Occident. Thereof, 412 physicians and 219 surgeons can be documented by their names. The ranking list of the most frequented medical faculties (Vienna, Padova, Leyden, Utrecht, Jena, Lipsia, Erlangen, Frankfort‐on‐Oder, Goettingen, Basel etc.) proves that all of these medical men received their professional education (being sponsored socially) from the then most excellent foreign universities. Thus, studies abroad guaranteed continual transfer of knowledge from Western to Eastern Europe. This situation seems to partially have compensated the disadvantages of lacking own Transylvanian universities ‐ at least from the quality point of view, so that the professional standard of the education of doctors working in Transylvania used to correspond to the highest level of European medicine.
It is not known whether frequent platelet donations provoke the platelet precount of the donor to... more It is not known whether frequent platelet donations provoke the platelet precount of the donor to rise or to decline. Therefore, with regard to the maximally possible safety of our donors we looked back onto the platelet counts of platelet donors who had given their platelets at constant 2-week intervals. Even frequent plateletphereses at 2-week intervals do not provoke thrombocytosis or thrombopenia for donors with normal platelet counts (> 200/nl, < 400/nl). Moreover, our donors appeared to regulate their platelet counts in an 'intelligent' manner.
BackgroundMore granulocyte concentrates (GCs) could be produced for more patients from the same d... more BackgroundMore granulocyte concentrates (GCs) could be produced for more patients from the same donor if apheresis bags were split and stored for longer periods of time. Hence, we tested the hypothesis that splitting and extension of storage of GCs do not impair granulocyte function or viability.Study Design and MethodsGranulocyte apheresis concentrates were produced using modified fluid gelatin as a separation enhancer, split into two portions, and stored for 24 and 48 h. Granulocyte function, represented by cell migration, reactive oxygen species (ROS) production, and neutrophil extracellular trap formation (NETosis), was measured by live‐cell imaging. ROS production, adhesive surface protein expression, and viability were measured by flow cytometry.ResultsSplitting had no effect on any of the tested parameters. After 24 h of storage, live‐cell imaging showed no significant difference in migration, time to maximum ROS production, time to half‐maximum NETosis, viability, or CD11b e...
ZusammenfassungDie Extrakorporale Photopherese ist ein etabliertes Therapieverfahren für Patiente... more ZusammenfassungDie Extrakorporale Photopherese ist ein etabliertes Therapieverfahren für Patienten mit T-Zell vermittelten Erkrankungen. Dabei besteht das Verfahren aus der Gewinnung autologer mononukleärer Zellen, deren Behandlung mit 8-Methoxypsoralen und UVA-Licht und die Retransfusion der behandelten Zellen.Die Wirkmechanismen der Photopherese sind zwar noch nicht vollständig geklärt, ein zentraler Mechanismus stellt jedoch die Apoptose mononukleärer Zellen dar. Das Ziel der Studie war eine Optimierung der Photopherese im Hinblick auf die Behandlung der Zellen mit 8-Methoxypsoralen/UVA und der daraus induzierten verstärkten Apoptose der Lymphozyten. Dabei sind einige Faktoren bekannt, welche die Effektivität der 8-Methoxypsoralen/UVA-Behandlung der Zellen beeinflussen können, wie z.B. der Hämatokrit oder die UVA-Dosis. Unser Fokus lag auf der Verfügbarkeit der photoaktiven Substanz und dem Einfluss der Zellsuspensionsmatrix auf die Apoptose der Lymphozyten.Die Verfügbarkeit von ...
A novel active resonant turn-on snubber which feeds back the energy stored in the snubber inducto... more A novel active resonant turn-on snubber which feeds back the energy stored in the snubber inductor is analyzed. The energy is transformed by a resonant operating sequence. Due to the resonant transformation, most of the stored energy is fed back. The circuit is demonstrated with a 300 V, 100 A buck-boost converter.
More than 40 human infections with the zoonotic Borna disease virus 1 (BoDV-1) have been reported... more More than 40 human infections with the zoonotic Borna disease virus 1 (BoDV-1) have been reported to German health authorities from endemic regions in southern and eastern Germany. Diagnosis of a confirmed case is based on the detection of BoDV-1 RNA or BoDV-1 antigen. In parallel, serological assays such as ELISA, immunoblots, and indirect immunofluorescence are in use to detect the seroconversion of Borna virus-reactive IgG in serum or cerebrospinal fluid (CSF). As immunopathogenesis in BoDV-1 encephalitis appears to be driven by T cells, we addressed the question of whether an IFN-γ-based ELISpot may further corroborate the diagnosis. For three of seven BoDV-1-infected patients, peripheral blood mononuclear cells (PBMC) with sufficient quantity and viability were retrieved. For all three patients, counts in the range from 12 to 20 spot forming units (SFU) per 250,000 cells were detected upon the stimulation of PBMC with a peptide pool covering the nucleocapsid protein of BoDV-1. ...
The first perpetual university in Transylvania was founded rather late compared to European stand... more The first perpetual university in Transylvania was founded rather late compared to European standards, namely only in 1872 in Klausenburg (Cluj, Kolozsvár). Through the centuries, the social request for physicians was satisfied by the education of Transylvanian students at foreign universities and by the immigration of physicians from abroad. Concerning the period from 1180 to 1849, we know about 7145 Transylvanian students at more than 80 different universities of the Occident. Thereof, 412 physicians and 219 surgeons can be documented by their names. The ranking list of the most frequented medical faculties (Vienna, Padova, Leyden, Utrecht, Jena, Lipsia, Erlangen, Frankfort‐on‐Oder, Goettingen, Basel etc.) proves that all of these medical men received their professional education (being sponsored socially) from the then most excellent foreign universities. Thus, studies abroad guaranteed continual transfer of knowledge from Western to Eastern Europe. This situation seems to partially have compensated the disadvantages of lacking own Transylvanian universities ‐ at least from the quality point of view, so that the professional standard of the education of doctors working in Transylvania used to correspond to the highest level of European medicine.
It is not known whether frequent platelet donations provoke the platelet precount of the donor to... more It is not known whether frequent platelet donations provoke the platelet precount of the donor to rise or to decline. Therefore, with regard to the maximally possible safety of our donors we looked back onto the platelet counts of platelet donors who had given their platelets at constant 2-week intervals. Even frequent plateletphereses at 2-week intervals do not provoke thrombocytosis or thrombopenia for donors with normal platelet counts (> 200/nl, < 400/nl). Moreover, our donors appeared to regulate their platelet counts in an 'intelligent' manner.
BackgroundMore granulocyte concentrates (GCs) could be produced for more patients from the same d... more BackgroundMore granulocyte concentrates (GCs) could be produced for more patients from the same donor if apheresis bags were split and stored for longer periods of time. Hence, we tested the hypothesis that splitting and extension of storage of GCs do not impair granulocyte function or viability.Study Design and MethodsGranulocyte apheresis concentrates were produced using modified fluid gelatin as a separation enhancer, split into two portions, and stored for 24 and 48 h. Granulocyte function, represented by cell migration, reactive oxygen species (ROS) production, and neutrophil extracellular trap formation (NETosis), was measured by live‐cell imaging. ROS production, adhesive surface protein expression, and viability were measured by flow cytometry.ResultsSplitting had no effect on any of the tested parameters. After 24 h of storage, live‐cell imaging showed no significant difference in migration, time to maximum ROS production, time to half‐maximum NETosis, viability, or CD11b e...
ZusammenfassungDie Extrakorporale Photopherese ist ein etabliertes Therapieverfahren für Patiente... more ZusammenfassungDie Extrakorporale Photopherese ist ein etabliertes Therapieverfahren für Patienten mit T-Zell vermittelten Erkrankungen. Dabei besteht das Verfahren aus der Gewinnung autologer mononukleärer Zellen, deren Behandlung mit 8-Methoxypsoralen und UVA-Licht und die Retransfusion der behandelten Zellen.Die Wirkmechanismen der Photopherese sind zwar noch nicht vollständig geklärt, ein zentraler Mechanismus stellt jedoch die Apoptose mononukleärer Zellen dar. Das Ziel der Studie war eine Optimierung der Photopherese im Hinblick auf die Behandlung der Zellen mit 8-Methoxypsoralen/UVA und der daraus induzierten verstärkten Apoptose der Lymphozyten. Dabei sind einige Faktoren bekannt, welche die Effektivität der 8-Methoxypsoralen/UVA-Behandlung der Zellen beeinflussen können, wie z.B. der Hämatokrit oder die UVA-Dosis. Unser Fokus lag auf der Verfügbarkeit der photoaktiven Substanz und dem Einfluss der Zellsuspensionsmatrix auf die Apoptose der Lymphozyten.Die Verfügbarkeit von ...
Uploads
Papers by Robert Offner