344 results on '"K, Bremer"'
Search Results
2. Nonlinearity and dynamics in RF Oscillators: Analysis and design implications.
- Author
-
Jan-K. Bremer, Marco Reit, Jan Przytarski, and Wolfgang Mathis
- Published
- 2010
- Full Text
- View/download PDF
3. Mixed-logic Dynamical System Modeling of SigmaDelta-modulators and its Application to Stability Analysis.
- Author
-
Jens Anders, Jan-K. Bremer, and Wolfgang Mathis
- Published
- 2009
- Full Text
- View/download PDF
4. A Nonlinear Systematic Design Flow for LC Tank VCOs based on Large Signal Capacitance Modeling.
- Author
-
Jan-K. Bremer, Christoph Zorn, Jan Przytarski, and Wolfgang Mathis
- Published
- 2009
- Full Text
- View/download PDF
5. Grüne Liste Prävention – Eine Datenbank evidenzbasierter Präventionsprogramme
- Author
-
K Bremer, R Brender, F Groeger-Roth, and U Walter
- Published
- 2022
6. Datenbank Grüne Liste Prävention – Was steckt drin? Systematische Charakterisierung der Programme in der Grünen Liste Prävention
- Author
-
R Brender, K Bremer, F Groeger-Roth, and U Walter
- Published
- 2022
7. Ansätze zur Ordnungsreduktion von nichtlinearen Oszillatormodellen zur Anwendung im Schaltungsentwurf
- Author
-
M. Reit, J.-K. Bremer, W. Mathis, and R. Stoop
- Subjects
Engineering (General). Civil engineering (General) ,TA1-2040 - Abstract
Im Rahmen dieser Arbeit wird ein Konzept zur Ordnungsreduktion von höherdimensionalen nichtlinearen Oszillatormodellen vorgestellt. Hierbei werden zwei wesentliche Ziele verfolgt. Zum einen wird eine höherdimensionale Modellierung der Oszillatorschaltung verwendet. Hierdurch lassen sich die Einflüsse parasitärer Effekte sowie struktureller Erweiterungen auf das dynamische Verhalten des Systems berücksichtigen. Zum anderen wird durch eine anschließende Ordnungsreduktion über die Methode der Zentrumsmannigfaltigkeit eine zweidimensionale Systembeschreibung erzeugt, deren wesentliche Dynamik derjenigen des höherdimensionalen Systems entspricht. Durch diese, in der Ordnung reduzierte, nichtlineare und parameterabhängige Systembeschreibung wird die Anwendbarkeit nichtlinearer Analysemethoden ermöglicht bzw. vereinfacht. Mit der Anwendung der Andronov-Hopf-Bifurkationsanalyse auf das reduzierte System lässt sich eine Stabilitätsuntersuchung durchführen sowie die Amplitude und Frequenz aller Zustandsgrößen approximieren. Das vorgestellte Konzept wird anhand des Beispielsystems eines LC-Tank-VCOs durchgeführt. In this paper, an order reduction technique for higher-dimensional nonlinear oscillator models, based on a center manifold approach, is presented. By modeling the oscillator circuit in the higher-dimensional state space, influences of parasitic elements and of structural extensions of the oscillator architecture on the dynamical system behavior can be examined. Using the proposed order reduction technique, a generalized second order model will be derived, which includes selected design parameters of the higher order model. By using an Andronov-Hopf bifurcation analysis, the reduced system can be studied with respect to stability as well as the amplitude and frequency of the individual state variables. The concept is applied to the design of LC-tank VCOs.
- Published
- 2010
- Full Text
- View/download PDF
8. Modellierungskonzept für MOS Varaktoren zur Minimierung der AM-FM Konversion in VCOs
- Author
-
T. Peikert, J.-K. Bremer, and W. Mathis
- Subjects
Engineering (General). Civil engineering (General) ,TA1-2040 - Abstract
In dieser Arbeit wird ein analytisches Simulationsmodell für MOS Varaktoren zur Entwurfsunterstützung von integrierten CMOS LC-Tank VCO-Schaltungen präsentiert. Das analytische Simulationsmodell wurde auf Basis des EKV-Transistormodells implementiert und beinhaltet ausschließlich Design- und Prozessparameter für die Berechnung der Varaktorkapazität. Dieses Simulationsmodell ermöglicht es, die verwendeten Varaktoren im Vorfeld des VCO-Entwurfs zu dimensionieren, die effektive Großsignalkapazität in Abhängigkeit des Ausgangssignals zu berechnen und einzelne Eigenschaften der Varaktoren, wie z.B. das AM-FM Konversionsverhalten zu optimieren. Die Gültigkeit des vorgestellten analytischen Simulationsmodells zur Beschreibung der Varaktorkapazität in CMOS LC-Tank VCOs, wird anhand von Spectre (Cadence) Simulationen auf Basis eines 0.25 μm CMOS Prozesses der Firma IHP (SGB25) und eines 0.35 μm CMOS Prozesses der Firma AMS (C35) verifiziert. In this work an analytical simulation model for MOS varactors, that can be used in a systematically VCO design flow, is presented. The simulation model is based on the EKV transistor model and includes only design and process parameters of the used CMOS technology. The proposed simulation model allows calculating the required design parameters and the effective large signal capacitance of the varactors incorporated into the VCO as a function of the output signal of the VCO. Based on the expression for the effective large signal capacitance it is possible to optimize the AM-FM conversion behavior of the used varactors. The validity and accuracy of the simulation model is verified by Spectre simulations which are based on a 0.25 μm CMOS process (SGB25) from the company IHP and a 0.35 μm CMOS process (C35) from the company AMS. The simulation results show a good accordance in all transistor operating regions for NMOS varactors as well as PMOS varactors.
- Published
- 2010
- Full Text
- View/download PDF
9. Nichtlineare Analyse von LC-TANK VCOs unter Berücksichtigung parasitärer Substrateffekte
- Author
-
J. Przytarski, J.-K. Bremer, and W. Mathis
- Subjects
Engineering (General). Civil engineering (General) ,TA1-2040 - Abstract
In dieser Arbeit wird ein Konzept vorgestellt, die Schaltungsarchitektur des LC-Tank-VCOs im höherdimensionalen Zustandsraum zu modellieren. Dabei wurde die VCO-Schaltung auf dominante nichtlineare und asymmetrische Effekte näher untersucht. Das entwickelte Modell bildet die Grundlage für nachfolgende parameterabhängige Analysen der Oszillatorschaltung mittels der Andronov-Hopf Bifurkationsanalyse. Zu diesem Zweck wurde ein höherdimensionales Modell entwickelt, welches für die Bifurkationsanalyse auf ein System 2. Ordnung reduziert werden muss. Als mathematisches Hilfsmittel zur Ordnungsreduktion des Systems wird das Verfahren der Zentrumsmannigfaltigkeit verwendet. Das Differentialgleichungssystem wird sehr schaltungsnah aufgestellt, daraus resultiert der Vorteil einer genaueren Repräsentation des physikalischen Verhaltens der Schaltung. Ziel ist es möglichst viele Effekte die sich auf das Verhalten des VCOs auswirken können, mit zu berücksichtigen.
- Published
- 2009
10. Bifurkationsanalyse eines LC Tank VCOs unter Berücksichtigung der variablen Kapazität
- Author
-
J.-K. Bremer, C. Zorn, and W. Mathis
- Subjects
Engineering (General). Civil engineering (General) ,TA1-2040 - Abstract
In dieser Arbeit präsentieren wir einen neuartigen Ansatz für den systematischen Entwurf von integrierten LC Tank VCO-Schaltungen basierend auf dem Andronov Hopf Theorem und der Störungstheorie. Der Ansatz ermöglicht es, eine Abschätzung des resultierenden Abstimmbereichs, eine Stabilitätsanalyse und eine Berechnung der Amplitude des VCOs im Vorfeld des eigentlichen Entwurfs durchzuführen. Des Weiteren erlaubt die vorgestellte Methode eine Optimierung des VCOs hinsichtlich der in den Spezifikationen geforderte Amplitude und eine Minimierung der höheren Harmonischen. Mit Hilfe eines ladungsbasierten MOS-Modells ist es möglich die spannungsabhängige Kapazität der Varaktortransistoren durch einen analytischen Ausdruck zu beschreiben. Auf Basis dieses analytischen Ausdrucks wird die amplitudenabhängige Großsignalkapazität des VCOs in Abhängigkeit von Designparametern und der Tuningspannung modelliert. Die Gültigkeit der vorgestellte Entwurfsmethode wird anhand eines Beispielentwurfes eines 2.4 GHz VCO unter Verwendung einer 0.25 μm HF-CMOS Technologie verifiziert.
- Published
- 2009
11. Nichtlineare Rauschmodellierung von LC Tank VCOs
- Author
-
T. Thiessen, J.-K. Bremer, and W. Mathis
- Subjects
Engineering (General). Civil engineering (General) ,TA1-2040 - Abstract
Im Rahmen dieser Arbeit wird ein alternativer Ansatz zur Phasenrauschoptimierung von LC-Tank Oszillatoren (VCOs) unter Verwendung stochastischer Differentialgleichungen vorgestellt. Zunächst werden die linearen Ansätze von Leeson, Hajimiri und Lee analysiert und bewertet. Danach wird ein Konzept vorgestellt, mit dem man die Rauscheigenschaften von VCOs auf der Grundlage stochastischer Differentialgleichungen und Fokker-Planck-Gleichungen untersuchen kann. Ziel dieser Arbeit ist eine Beschreibung des Phasenrauschens auf der Basis einer nichtlinearen Rauschmodellierung, welche Parameter eines VCOs für eine Optimierung beinhaltet. Es wurde ein Matlab-Tool erstellt und die Funktionalität anhand von Simulationen verifiziert.
- Published
- 2008
12. Ansätze für eine Bifurkationsanalyse von RF LC-Tank VCOs unter Berücksichtigung nichtlinearer Bauelementegleichungen
- Author
-
C. Zorn, J.-K. Bremer, and W. Mathis
- Subjects
Engineering (General). Civil engineering (General) ,TA1-2040 - Abstract
Es wird ein alternativer Ansatz zum Entwurf von vollintegrierten LC Oszillatoren mit Hilfe der Andronov-Hopf Bifurkationsanalyse unter Einbeziehung eines nichtlinearen Overall-Modells für MOS-Transistoren (EKV-Modell) vorgestellt. Das in dieser Arbeit vorgestellte Verfahren beschreibt die MOS-Kapazität des VCOs über geometrische Gundgrößen, die damit nur als Längen- und Weitenverhältnisse in die Bifurkationsanalyse eingehen. Zur Beschreibung der MOS-Kapazität wurde ein Basic-Charge-Modell, wie es in den Arbeiten von Enz und Vittoz vorgestellt wurde, in Verbindung einer expliziten analytischen Näherung des Oberflächenpotenzials verwendet. Das Verfahren ermöglicht es, als zusätzlichen Freiheitsgrad für den Designer auch die Amplitude zur Optimierung der Bauteilparameter heranzuziehen und vorab eine genauere Abschätzung der Parameter des Varaktors zu erhalten. Zusammengefasst in einer Toolbox führt die Anwendung des Verfahrens auf einen grafischen Optimierungsprozess, mit dessen Hilfe die Parameter analytisch bestimmt werden können. Die verwendete Methode erweitert den von Hajimiri und Ham vorgestellten Entwurfsprozess von LC-Tank VCOs um eine Stabilitätsanalyse, die Berücksichtigung harmonischer höherer Ordnung und die physikalisch exakte Modellierung der Varaktorkapazitäten.
- Published
- 2008
13. Multidrug-resistant organisms predispose to relapsing cholangitis in liver graft recipients with stenosis of the biliary anastomosis
- Author
-
Dirk Walter, Philip G. Ferstl, Wolf O. Bechstein, Mireen Friedrich-Rust, Jonel Trebicka, S. Zeuzem, Michael Hogardt, Martin-Walter Welker, Natalie Filmann, Vaj Kempf, Alexander Queck, K Bremer, N Weiler, and Oliver Waidmann
- Subjects
Multiple drug resistance ,Liver graft ,medicine.medical_specialty ,Stenosis ,business.industry ,Internal medicine ,Medicine ,Biliary anastomosis ,business ,medicine.disease ,Gastroenterology - Published
- 2021
14. Analyse und Entwurf von hochbitratigen Clock-and-Data-Recovery Schaltungen in CMOS-Technologie
- Author
-
J.-K. Bremer, C. Zemko, J. Schmackers, and W. Mathis
- Subjects
Engineering (General). Civil engineering (General) ,TA1-2040 - Abstract
In dieser Arbeit wird ein neuartiges Schaltungskonzept für die Realisierung eines Phasendetektors einer Clock-and-Data-Recovery Schaltung vorgestellt. Es handelt sich hierbei um eine nichtlineare Phasendetektorarchitektur, die nach dem Verfahren von Alexander arbeitet. Um die Funktionalität des Phasendetektors im Hochfrequenzbereich zu gewährleisten, wurden in dem Design sehr schnell schaltende HLO-Flip-Flops (high-speed latching operation flip-flop) verwendet. Ein wesentliches Entwurfsziel war die Begrenzung des selbstgenerierten Jitters des Phasendetektors. Der Schaltungsentwurf wurde mit der Simulationsumgebung Cadence Spectre durchgeführt und die Funktionalität der Schaltung im GHz-Bereich anhand von ausgewählten Simulationen verifiziert. This paper presents a novel realization concept for Clock-and-Data-Recovery circuits. Our Design uses a nonlinear phase detector architecture, which is based on the Alexander phase detection method. In order to ensure circuit functionality in the RF region, we use very fast switching HLO-Flip-Flops (high-speed latching operation flip-flop) in our design. The primal goal in our design was the minimization of self induced jitter of the phase detector. The accuracy of our circuit design and the functionality in the GHz regime is confirmed by various circuit simulations executed with the SPECTRE Simulator.
- Published
- 2007
15. Das Verhalten nanostrukturierter Schaltungen unter der Berücksichtigung von Quanteneffekten
- Author
-
J.-K. Bremer, F. Felgenhauer, M. Begoin, and W. Mathis
- Subjects
Engineering (General). Civil engineering (General) ,TA1-2040 - Abstract
Aufgrund der Bedeutung der MOS-Technologie für Halbleiterindustrie und deren fortschreitende Miniaturisierung ist es wichtig sicherzustellen, dass die klassischen Schaltungskonzepte für stark skalierte Bauelemente nicht ihre Gültigkeit verlieren. Ziel unserer Arbeitsgruppe ist es ein Simulatorpaket zu entwickeln, welches von einer physikalischen Sicht heraus quantenmechanische Einflüsse in integrierten Schaltungen ermittelt und Konsequenzen für zukünftiges Schaltungsdesign prognostiziert. Zur Berechnung und Modellierung der Quanteneffekte wird ein auf dem "non equilibrium Green's functions" (NEGF) Formalismus basierender numerischer 1-dimensionaler Simulator entwickelt. Auf der Basis von numerischen Transportsimulationen werden Ersatzschaltbilder für die SPICE Simulationsumgebung erstellt, um den Einfluss der Quanteneffekte in die Schaltungssimulation einzubinden. In this paper we discuss the expected impact of quantum effects in nanostructured CMOS circuits. In order to describe transport in mesoscopic electronic systems our group develops a 1-d numerical simulation packet based on the "non equilibrium Green's functions" (NEGF) formalism. By means of the obtained simulation results we develop extended SPICE circuit models. With these SPICE models the influence of quantum effects to the functionality of classical circuit concepts can be studied. Using these results it is our intention to develop circuits with a higher robustness against these quantum effects. For the illustration of our simulation concept we discuss some results of some circuit examples.
- Published
- 2006
16. Germanistik in Deutschland und in Italien während der Covid-19-Krise. EIn Gespräch
- Author
-
M. Costa and K. Bremer
- Subjects
2019-20 coronavirus outbreak ,Fuel Technology ,History ,Coronavirus disease 2019 (COVID-19) ,Process Chemistry and Technology ,media_common.quotation_subject ,Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) ,Economic history ,Economic Geology ,Conversation ,German studies ,media_common ,Insegnamento universitario del tedesco - Published
- 2021
17. Viruses and their significance in agricultural and horticultural crops in Finland
- Author
-
E. TAPIO, K. BREMER, and J.P.T. VALKONEN
- Subjects
Agriculture ,Agriculture (General) ,S1-972 - Abstract
This paper reviews the plant viruses and virus vectors that have been detected in agricultural and horticultural crop plants and some weeds in Finland. The historical and current importance of virus diseases and the methods used for controlling them in cereals, potato, berry plants, fruit trees, ornamental plants and vegetables are discussed. Plant viruses have been intensely studied in Finland over 40 years. Up to date, 44 plant virus species have been detected, and many tentatively identified virus-es are also reported. Control of many virus diseases has been significantly improved. This has been achieved mainly through changes in cropping systems, production of healthy seed potatoes and healthy stocks of berry plants, fruit trees and ornamental plants in the institutes set up for such production, and improved hygiene. At the present, barley yellow dwarf luteovirus, potato Y potyvirus and potato mop-top furovirus are considred to be economically the most harmful plant viruses in Finland.
- Published
- 2008
18. Limited Open Reduction and Internal Fixation of Calcaneal Fractures
- Author
-
Lukas Kraler, Anne K. Bremer, Lars Frauchiger, Martin Weber, and Fabian Krause
- Subjects
Adult ,Male ,Adolescent ,medicine.medical_treatment ,Screw fixation ,03 medical and health sciences ,Fracture Fixation, Internal ,Fractures, Bone ,Young Adult ,0302 clinical medicine ,Calcaneal fracture ,Surveys and Questionnaires ,medicine ,Internal fixation ,Humans ,Orthopedics and Sports Medicine ,Reduction (orthopedic surgery) ,Aged ,Retrospective Studies ,Orthodontics ,030222 orthopedics ,business.industry ,030229 sport sciences ,Middle Aged ,medicine.disease ,Calcaneus ,Open Fracture Reduction ,Surgery ,Female ,business ,Lateral approach - Abstract
Background:The treatment of displaced intra-articular calcaneal fractures remains a challenge and the optimal approach is still controversial. The main reason to avoid the extended lateral approach is the high complication rate due to wound healing problems. We report on 16 years of experience with a standardized limited open reduction and internal fixation technique.Methods:Between 2001 and 2017, we prospectively followed 240 consecutive patients operatively treated for a displaced intra-articular calcaneal fracture. Patients with open, multiple, bilateral, extra-articular, and Sanders IV fractures and those lost to follow-up were excluded. A lateral subtalar approach was used, with a cast for 8 weeks and full weightbearing allowed after 12 weeks. Follow-up examinations were scheduled until 24 months. Subjective and clinical assessment included gait abnormality, subtalar and ankle range of motion, and stability and alignment. The American Orthopaedic Foot & Ankle Society (AOFAS) hindfoot score was calculated. Alignment was analyzed on standard radiographs. In total, 131 patients were excluded. The remaining 109 patients were followed for a minimum of 24 months (34.4 ± 14.2 [range, 24-102] months).Results:The mean AOFAS score was 87 ± 13 (range, 32-100). “Excellent” and “good” results, as well as hindfoot motion with “normal/mild” and “moderate” restrictions, were seen in 80% of patients. Early reoperations were performed for insufficient reduction (2 patients), delayed wound healing (debridement, 3 patients), and hematoma (1 patient). Late revisions were arthrodesis (3 patients), medializing calcaneal osteotomy (1 patient), and implant removal (53 patients; 49%).Conclusion:The presented approach has remained unmodified for 16 years and resulted in consistently good functional results. The main disadvantage was the high rate of heel screw removal.Level of Evidence:Level IV, retrospective case series.
- Published
- 2019
19. An update of the Angiosperm Phylogeny Group classification for the orders and families of flowering plants: APG IV
- Author
-
K. Bremer, Douglas E. Soltis, Pamela S. Soltis, Peter F. Stevens, J. L. Reveal, and Mark W. Chase
- Subjects
0106 biological sciences ,biology ,Corsiaceae ,Pandanales ,Plant Science ,biology.organism_classification ,010603 evolutionary biology ,01 natural sciences ,Achariaceae ,Asparagales ,Malpighiales ,Liliales ,Aquifoliales ,Botany ,Dilleniales ,Ecology, Evolution, Behavior and Systematics ,010606 plant biology & botany - Abstract
A revised and updated classification for the families of the flowering plants is provided. Newly adopted orders include Austrobaileyales, Canellales, Gunnerales, Crossosomatales and Celastrales. Pertinent literature published since the first APG classification is included, such that many additional families are now placed in the phylogenetic scheme. Among these are Hydnoraceae (Piperales), Nartheciaceae (Dioscoreales), Corsiaceae (Liliales), Triuridaceae (Pandanales), Hanguanaceae (Commelinales), Bromeliacae, Mayacaceae and Rapateaceae (all Poales), Barbeuiaceae and Gisekiaceae (both Caryophyllales), Geissolomataceae, Strasburgeriaceae and Vitaceae (unplaced to order, but included in the rosids), Zygophyllaceae (unplaced to order, but included in eurosids I), Bonnetiaceae, Ctenolophonaceae, Elatinaceae, Ixonanthaceae, Lophopyxidaceae, Podostemaceae (Malpighiales), Paracryphiaceae (unplaced in euasterid II), Sladeniaceae, Pentaphylacaceae (Ericales) and Cardiopteridaceae (Aquifoliales). Several major families are recircumscribed. Salicaceae are expanded to include a large part of Flacourtiaceae, including the type genus of that family; another portion of former Flacourtiaceae is assigned to an expanded circumscription of Achariaceae. Euphorbiaceae are restricted to the uniovulate subfamilies; Phyllanthoideae are recognized as Phyllanthaceae and Oldfieldioideae as Picrodendraceae. Scrophulariaceae are recircumscribed to include Buddlejaceae and Myoporaceae and exclude several former members; these are assigned to Calceolariaceae, Orobanchaceae and Plantaginaceae. We expand the use of bracketing families that could be included optionally in broader circumscriptions with other related families; these include Agapanthaceae and Amaryllidaceae in Alliaceae s.l. , Agavaceae, Hyacinthaceae and Ruscaceae (among many other Asparagales) in Asparagaceae s.l. , Dichapetalaceae in Chrysobalanaceae, Turneraceae in Passifloraceae, Erythroxylaceae in Rhizophoraceae, and Diervillaceae, Dipsacaceae, Linnaeaceae, Morinaceae and Valerianaceae in Caprifoliaceae s.l. © 2003 The Linnean Society of London, Botanical Journal of the Linnean Society , 2003, 141 , 399‐436.
- Published
- 2016
20. Ansätze zur Ordnungsreduktion von nichtlinearen Oszillatormodellen zur Anwendung im Schaltungsentwurf
- Author
-
Marco Reit, Ruedi Stoop, Wolfgang Mathis, and J.-K. Bremer
- Subjects
lcsh:TA1-2040 ,General Medicine ,lcsh:Engineering (General). Civil engineering (General) - Abstract
Im Rahmen dieser Arbeit wird ein Konzept zur Ordnungsreduktion von höherdimensionalen nichtlinearen Oszillatormodellen vorgestellt. Hierbei werden zwei wesentliche Ziele verfolgt. Zum einen wird eine höherdimensionale Modellierung der Oszillatorschaltung verwendet. Hierdurch lassen sich die Einflüsse parasitärer Effekte sowie struktureller Erweiterungen auf das dynamische Verhalten des Systems berücksichtigen. Zum anderen wird durch eine anschließende Ordnungsreduktion über die Methode der Zentrumsmannigfaltigkeit eine zweidimensionale Systembeschreibung erzeugt, deren wesentliche Dynamik derjenigen des höherdimensionalen Systems entspricht. Durch diese, in der Ordnung reduzierte, nichtlineare und parameterabhängige Systembeschreibung wird die Anwendbarkeit nichtlinearer Analysemethoden ermöglicht bzw. vereinfacht. Mit der Anwendung der Andronov-Hopf-Bifurkationsanalyse auf das reduzierte System lässt sich eine Stabilitätsuntersuchung durchführen sowie die Amplitude und Frequenz aller Zustandsgrößen approximieren. Das vorgestellte Konzept wird anhand des Beispielsystems eines LC-Tank-VCOs durchgeführt. In this paper, an order reduction technique for higher-dimensional nonlinear oscillator models, based on a center manifold approach, is presented. By modeling the oscillator circuit in the higher-dimensional state space, influences of parasitic elements and of structural extensions of the oscillator architecture on the dynamical system behavior can be examined. Using the proposed order reduction technique, a generalized second order model will be derived, which includes selected design parameters of the higher order model. By using an Andronov-Hopf bifurcation analysis, the reduced system can be studied with respect to stability as well as the amplitude and frequency of the individual state variables. The concept is applied to the design of LC-tank VCOs.
- Published
- 2018
21. Modellierungskonzept für MOS Varaktoren zur Minimierung der AM-FM Konversion in VCOs
- Author
-
J.-K. Bremer, Wolfgang Mathis, and Tim Peikert
- Subjects
Transistor model ,Engineering ,business.industry ,Transistor ,Electrical engineering ,General Medicine ,Capacitance ,Die (integrated circuit) ,law.invention ,PMOS logic ,Voltage-controlled oscillator ,CMOS ,lcsh:TA1-2040 ,law ,Electronic engineering ,lcsh:Engineering (General). Civil engineering (General) ,business ,NMOS logic - Abstract
In dieser Arbeit wird ein analytisches Simulationsmodell für MOS Varaktoren zur Entwurfsunterstützung von integrierten CMOS LC-Tank VCO-Schaltungen präsentiert. Das analytische Simulationsmodell wurde auf Basis des EKV-Transistormodells implementiert und beinhaltet ausschließlich Design- und Prozessparameter für die Berechnung der Varaktorkapazität. Dieses Simulationsmodell ermöglicht es, die verwendeten Varaktoren im Vorfeld des VCO-Entwurfs zu dimensionieren, die effektive Großsignalkapazität in Abhängigkeit des Ausgangssignals zu berechnen und einzelne Eigenschaften der Varaktoren, wie z.B. das AM-FM Konversionsverhalten zu optimieren. Die Gültigkeit des vorgestellten analytischen Simulationsmodells zur Beschreibung der Varaktorkapazität in CMOS LC-Tank VCOs, wird anhand von Spectre (Cadence) Simulationen auf Basis eines 0.25 μm CMOS Prozesses der Firma IHP (SGB25) und eines 0.35 μm CMOS Prozesses der Firma AMS (C35) verifiziert. In this work an analytical simulation model for MOS varactors, that can be used in a systematically VCO design flow, is presented. The simulation model is based on the EKV transistor model and includes only design and process parameters of the used CMOS technology. The proposed simulation model allows calculating the required design parameters and the effective large signal capacitance of the varactors incorporated into the VCO as a function of the output signal of the VCO. Based on the expression for the effective large signal capacitance it is possible to optimize the AM-FM conversion behavior of the used varactors. The validity and accuracy of the simulation model is verified by Spectre simulations which are based on a 0.25 μm CMOS process (SGB25) from the company IHP and a 0.35 μm CMOS process (C35) from the company AMS. The simulation results show a good accordance in all transistor operating regions for NMOS varactors as well as PMOS varactors.
- Published
- 2018
22. Nichtlineare Analyse von LC-TANK VCOs unter Berücksichtigung parasitärer Substrateffekte
- Author
-
Wolfgang Mathis, J.-K. Bremer, and Jan Przytarski
- Subjects
lcsh:TA1-2040 ,General Medicine ,lcsh:Engineering (General). Civil engineering (General) - Abstract
In dieser Arbeit wird ein Konzept vorgestellt, die Schaltungsarchitektur des LC-Tank-VCOs im höherdimensionalen Zustandsraum zu modellieren. Dabei wurde die VCO-Schaltung auf dominante nichtlineare und asymmetrische Effekte näher untersucht. Das entwickelte Modell bildet die Grundlage für nachfolgende parameterabhängige Analysen der Oszillatorschaltung mittels der Andronov-Hopf Bifurkationsanalyse. Zu diesem Zweck wurde ein höherdimensionales Modell entwickelt, welches für die Bifurkationsanalyse auf ein System 2. Ordnung reduziert werden muss. Als mathematisches Hilfsmittel zur Ordnungsreduktion des Systems wird das Verfahren der Zentrumsmannigfaltigkeit verwendet. Das Differentialgleichungssystem wird sehr schaltungsnah aufgestellt, daraus resultiert der Vorteil einer genaueren Repräsentation des physikalischen Verhaltens der Schaltung. Ziel ist es möglichst viele Effekte die sich auf das Verhalten des VCOs auswirken können, mit zu berücksichtigen.
- Published
- 2018
23. Special fibres and components
- Author
-
B. Lustermann, K. Bremer, Getinet Woyessa, and C.-A. Bunge
- Subjects
Optical fiber ,Materials science ,Optics ,Bending (metalworking) ,Sensing applications ,law ,business.industry ,Grating ,Manufacturing methods ,business ,law.invention - Abstract
In this chapter we present more specific fibre types for particular applications. Starting with the multi-core fibre, which can be used as a substitution for ordinary SI-POF transmission fibres, but with better bending losses, over the ever increasing range of micro-structured POF for diverse sensing applications to fibres for illumination purposes or tubular fibres for the detection of sparks in electrical cables. Finally, a review on gratings in optical fibres and POFs in particular concludes the chapter. The different grating types, manufacturing methods and applications will be presented.
- Published
- 2017
24. List of contributors
- Author
-
G. Aldabaldetreku, E. Arrospide, M. Beckers, M. Beer, I. Bikandi, K. Bremer, C.-A. Bunge, C. Dieling, G. Durana, R. Evert, I. García, T. Gries, S. Kalapis, P. Kröplin, B. Lustermann, V. Mecnika, M. Plümpe, T. Schlüter, V. Schrank, M. Schüppert, G. Seide, G. Stepniak, B. Weise, G. Woyessa, D. Zaremba, and J. Zubia
- Published
- 2017
25. Energy metabolism and cytochrome oxidase activity: linking metabolism to gene expression
- Author
-
K. Bremer, K.M. Kocha, T. Snider, and C.D. Moyes
- Subjects
Cytochrome oxidase activity ,biology ,Biochemistry ,Gene expression ,biology.protein ,Energy metabolism ,Cytochrome c oxidase ,Animal Science and Zoology ,Metabolism ,Mitochondrion ,Gene ,Genome ,Ecology, Evolution, Behavior and Systematics - Abstract
Modification of mitochondrial content demands the synthesis of hundreds of proteins encoded by nuclear and mitochondrial genomes. The responsibility for coordination of this process falls to nuclear-encoded master regulators of transcription. DNA-binding proteins and coactivators integrate information from energy-sensing pathways and hormones to alter mitochondrial gene expression. In mammals, the signaling cascade for mitochondrial biogenesis can be described as follows: hormonal signals and energetic information are sensed by protein-modifying enzymes that in turn regulate the post-translational modification of transcription factors. Once activated, transcription-factor complexes form on promoter elements of many of the nuclear-encoded mitochondrial genes, recruiting proteins that remodel chromatin and initiate transcription. One master regulator in mammals, PGC-1α, is well studied because of its role in determining the metabolic phenotype of muscles, but also due to its importance in mitochondria-related metabolic diseases. However, relatively little is known about the role of this pathway in other vertebrates. These uncertainties raise broader questions about the evolutionary origins of the pathway and its role in generating the diversity in muscle metabolic phenotypes seen in nature.
- Published
- 2014
26. Prospective Use of a Standardized Nonoperative Early Weightbearing Protocol for Achilles Tendon Rupture: 17 Years of Experience
- Author
-
Thorsten Müller, Fabian Krause, Anne K. Bremer, Martin Weber, and Timo M. Ecker
- Subjects
Adult ,Male ,medicine.medical_specialty ,medicine.medical_treatment ,Foot Orthoses ,Physical Therapy, Sports Therapy and Rehabilitation ,medicine.disease_cause ,Achilles Tendon ,Weight-bearing ,Weight-Bearing ,03 medical and health sciences ,0302 clinical medicine ,Patient satisfaction ,Tendon Injuries ,medicine ,Humans ,Orthopedics and Sports Medicine ,Muscle Strength ,Prospective Studies ,Prospective cohort study ,610 Medicine & health ,Physical Therapy Modalities ,Aged ,030222 orthopedics ,Achilles tendon ,Rehabilitation ,business.industry ,030229 sport sciences ,Evidence-based medicine ,Middle Aged ,Surgery ,Tendon ,Casts, Surgical ,medicine.anatomical_structure ,Patient Satisfaction ,Physical therapy ,Female ,Achilles tendon rupture ,medicine.symptom ,business ,Follow-Up Studies - Abstract
Background: Acute traumatic rupture of the Achilles tendon can be treated operatively or nonoperatively. Throughout the literature, there is no consensus regarding the optimal treatment protocol. Purpose: To report on 17 years of experience with treating this injury with a standardized nonoperative treatment protocol. Study Design: Case Series; Level of evidence, 4. Methods: The treatment protocol was based on a combination of an equinus cast and rehabilitation boot, which promoted immediate full weightbearing and early functional rehabilitation. A total of 171 patients were consecutively treated and prospectively followed from 1996 to 2013. Assessed were subjective parameters such as pain, loss of strength, return to previous activity level, meteosensitivity, and general satisfaction with the treatment outcome. Clinical assessment included testing of plantar flexion strength and endurance, calf circumference, and tendon length. Subjective and clinical parameters were then used to calculate a modified Thermann score. The correlation between tendon lengthening and function was calculated using the Pearson correlation coefficient. Results: A total of 114 patients were followed for a minimum of 12 months (mean, 27 ± 20 months; range, 12-88 months). The mean Thermann score was 82 ± 13 (range, 41-100), and subjective satisfaction was rated “very good” and “good” in 90%. An inverse correlation was found between tendon length and muscle strength ( R = −0.3). There were 11 reruptures (8 with and 3 without an adequate trauma). General complications were 5 deep venous thromboses, 1 complex regional pain syndrome, and minor problems such as transient heel pain (n = 3), heel numbness (n = 1), and cast-associated skin abrasions (n = 4). Conclusion: Seventeen years of experience with a nonoperative treatment protocol for acute rupture of the Achilles tendon confirmed good functional outcome and patient satisfaction. Reruptures mostly occurred with new traumatic events in the vulnerable phase from 6 to 12 weeks after the initial injury. Muscle strength correlated to tendon length, making its assessment a crucial follow-up parameter. The protective equinus cast and boot can protect against excessive tendon lengthening during the healing process.
- Published
- 2016
- Full Text
- View/download PDF
27. Hybridization in Sunfish Influences the Muscle Metabolic Phenotype
- Author
-
Rhiannon Davies, K. Bremer, Christopher D. Moyes, Yuxiang Wang, A. D. Hume, and Katherine E. Mathers
- Subjects
Fish Proteins ,Male ,Physiology ,Molecular Sequence Data ,Oxidative phosphorylation ,Mitochondrion ,Biology ,DNA, Mitochondrial ,Polymerase Chain Reaction ,Biochemistry ,Oxidative Phosphorylation ,Lepomis ,chemistry.chemical_compound ,Lactate dehydrogenase ,Animals ,Glycolysis ,Muscle, Skeletal ,Base Sequence ,Aldolase A ,biology.organism_classification ,Mitochondria ,Perciformes ,Phenotype ,Electron Transport Chain Complex Proteins ,chemistry ,Coenzyme Q – cytochrome c reductase ,biology.protein ,Hybridization, Genetic ,Female ,Animal Science and Zoology ,Energy Metabolism ,Sequence Alignment ,Pyruvate kinase - Abstract
Hybridization has the potential to exert pleiotropic effects on metabolism. Effects on mitochondrial enzymes may arise through incompatibilities in nuclear- and mitochondrial-encoded subunits of the enzyme complexes of oxidative phosphorylation. We explored the metabolic phenotype of bluegill (Lepomis macrochirus), pumpkinseed (Lepomis gibbosus), and their unidirectional F(1) hybrids (male bluegill × female pumpkinseed). In hybrids, glycolytic enzyme activities were indistinguishable from (aldolase, pyruvate kinase) or intermediate to (lactate dehydrogenase, phosphoglucoisomerase) parentals, but complex IV activities aligned with pumpkinseed, both 30% lower than bluegill. In isolated mitochondria, the specific activities of complexes I, II, and V were indistinguishable between groups. However, both complex III and IV showed indications of depressed activities in hybrid mitochondria, though no effects on mitochondrial state 3 or state 4 respiration were apparent. The patterns in complex IV activities were due to differences in enzyme content rather than enzyme V(max); immunoblots comparing complex IV content with catalytic activity were indistinguishable between groups. The sequence differences in complex IV catalytic subunits (CO1, CO2, CO3) were minor in nature; however, the mtDNA-encoded subunit of complex III (cytochrome b) showed eight differences between bluegill and pumpkinseed, several of which could have structural consequences to the multimeric enzyme, contributing to the depressed complex III catalytic activity in hybrids.
- Published
- 2012
28. Evidenzbasiertes Konzept zur Nachsorge für Kinder und Jugendliche mit Adipositas nach ambulanter oder stationärer Rehabilitation
- Author
-
I. Gellhaus, T. Lob-Corzilius, K. Heber, K. Bremer, Rainer Stachow, A. Gahler, B. Daas, A. Büssenschütt, B. Sievers-Böckel, I. Eggers, A. Baudach, R. Jaeschke, S. Wiegand, K. Stübing, V. Faustin, G. Ramos, A. von Egmond-Fröhlich, and J. Möttig
- Subjects
business.industry ,Rehabilitation ,Medicine ,Physical Therapy, Sports Therapy and Rehabilitation ,business - Published
- 2012
29. Feedback Stabilized Interrogation Technique for EFPI/FBG Hybrid Fiber-Optic Pressure and Temperature Sensors
- Author
-
K. Bremer, I. Mueller, Steffen Lochmann, B. Moss, Elfed Lewis, and Gabriel Leen
- Subjects
Optical fiber ,Materials science ,business.industry ,Physics::Optics ,Temperature measurement ,Pressure sensor ,law.invention ,Interferometry ,Optics ,Fiber Bragg grating ,Fiber optic sensor ,law ,Optoelectronics ,Electrical and Electronic Engineering ,business ,Instrumentation ,Fabry–Pérot interferometer ,Tunable laser - Abstract
This paper discusses a Single Wavelength Interrogation (SWI) technique used to measure fast changing pressure related signals and over a large operational temperature range. The novel technique is based on a fiber-optic pressure and temperature hybrid sensor, and a feedback stabilization technique for a tunable laser source. The fiber-optic hybrid sensor consists of a miniature diaphragm based all-silica Extrinsic Fabry-Perot Interferometric (EFPI) Fiber-Optic Pressure Sensor (FOPS) which additionally incorporates a Fiber Bragg Grating (FBG) temperature sensor. The FBG temperature sensor is used as a feedback element to stabilize the output wavelength of the tunable laser source to operate always in the linear range of the EFPI FOPS.
- Published
- 2012
30. Design of nonlinear CMOS circuits in the Nano-GHz Era and its mathematical challenges
- Author
-
W. Mathis and J. K. Bremer
- Subjects
HiperLAN ,Numerical Analysis ,RF front end ,General Computer Science ,Computer science ,business.industry ,Applied Mathematics ,Circuit design ,Hardware_PERFORMANCEANDRELIABILITY ,Theoretical Computer Science ,law.invention ,Bluetooth ,CMOS ,law ,Modeling and Simulation ,Hardware_INTEGRATEDCIRCUITS ,Electronic engineering ,Radio frequency ,Transceiver ,Telecommunications ,business ,Electronic circuit - Abstract
Modern communication systems are working on industrial, scientific and medical (ISM) radio frequency (RF) bands. Today most research and development activities in industrial companies and universities are concentrated to frequency bands between 1GHz and 24GHz up to 60GHz. For the construction of mixed-signal chips for cellular telephones and other wireless LAN applications (Bluetooth, HIPERLAN, etc.) different semiconductor technologies are used. In order to combine analogue functionality for the RF front end and digital functionality for high-speed signal processing nonlinear circuit concepts must be used and CMOS technology has to be applied. In order to construct high-quality RF transceiver chips a submicron CMOS technology (180 nm and below) is needed. Therefore we come into the Nano-GHz Era of circuit design. In this work corresponding mathematical challenges of modern RF CMOS design of transceiver circuits, with a focus on oscillator circuits, are discussed. It is shown that these circuits can be modelled as dynamical systems and their environment and their devices by partial differential equations. For circuit design aspects bifurcation theory and other mathematical concepts from dynamical systems as well as advanced numerical methods can be applied in order to build up an efficient design system for these RF CMOS circuits. In this paper some key aspects of future circuit design will be presented and discussed.
- Published
- 2011
31. Intraoperativer Abfall der Sevofluran- und O2-Konzentration
- Author
-
K. Bremer, M. Roiss, and G.N. Schmidt
- Subjects
medicine.medical_specialty ,Intra operative ,business.industry ,Drop (liquid) ,chemistry.chemical_element ,General Medicine ,Oxygen ,Sevoflurane ,Fresh gas flow ,Anesthesiology and Pain Medicine ,chemistry ,Anesthesiology ,Anesthesia ,Female patient ,Medicine ,Respiratory system ,business ,medicine.drug - Abstract
After problem-free induction of narcosis in an 84-year-old female patient an intra-operative drop in sevoflurane and oxygen concentrations occurred during low-flow anesthesia. Although the concentrations of sevoflurane and oxygen in the fresh gas flow were increased no adequate elevation of the inspiratory concentrations could be achieved. Disconnection of the Drager Primus IE manual bag-valve-mask could be identified as the cause of the drop in concentrations. Interestingly no error alarm function was initiated. This case demonstrates how important knowledge of the function, set-up and alarm conditions of respiratory machines is. This should be an important component of training in anesthesiology as well as securely established algorithms for difficult ventilation to ensure safe anesthesia despite technical failures.
- Published
- 2009
32. Studies of Human Peripheral Lymph II. Low Lymphocyte Count and Few B-Lymphocytes in Peripheral Lymph of Patients with Chronic Lymphocytic Leukaemia
- Author
-
A. Engeset, K. Bremer, and S. S. Frøiland
- Subjects
Adult ,Male ,Pathology ,medicine.medical_specialty ,Lymphocyte ,Cell ,Cell Count ,Dysgerminoma ,Leukocyte Count ,Testicular Neoplasms ,Bone Marrow ,Methods ,medicine ,Humans ,Lymphocytes ,Neoplasm Metastasis ,Lymph node ,Aged ,B-Lymphocytes ,biology ,business.industry ,Carcinoma ,Hematology ,Middle Aged ,Leukemia, Lymphoid ,medicine.anatomical_structure ,Lymphatic system ,Splenomegaly ,Immunology ,biology.protein ,Female ,Lymph ,Antibody ,business ,Peripheral lymph ,Subcutaneous tissue - Abstract
Peripheral lymph was studied in 11 patients with chronic lymphocytic leukaemia (CLL) with blood lymphocyte counts between 2,100 and 93,000/μl and in 8 control patients with solid tumours and haematologically normal with lymphocyte counts below 3,500/μl. The mean lymphocyte count in peripheral lymph in the two groups was about the same order, 123 and 149/μ1 respectively despite marked differences in blood lymphocyte count. This demonstrates that the leukaemic cells do not migrate to any significant extent into the subcutaneous tissue and back to the lymphatics. 5 of the 6 CLL patients studied had > 90 % B-lymphocytes (identified by their membrane bound immunoglobulin) in the blood representing both relatively and absolutely much higher blood B-lymphocyte values than normal (3–22 %). The percentage of B-lymphocytes in the lymph was 5 % or less with the exception of one patient with 50%. It is concluded that reduced lymphocyte recirculation in CLL does not depend on functionally altered lymph nodes since a direct effect of the lymph node on the cell number in peripheral lymph can be excluded. Our data indicate that the minimal recirculation to peripheral lymph depends on properties of the leukaemic cell possibly reflecting a normal B-cell characteristic.
- Published
- 2009
33. Comparative Studies on the in vitro Uptake of 3H-Cytidine and 3H-Uridine by Normal and Leukaemic Lymphocytes
- Author
-
W. Schreml, Eileen B. Harriss, and K. Bremer
- Subjects
Lymphocytosis ,Cell ,Cytidine ,Biology ,Tritium ,chemistry.chemical_compound ,Labelling ,Leukocytes ,Methods ,medicine ,Animals ,Humans ,Lymphocytes ,Uridine ,Temperature ,DNA ,Hematology ,Molecular biology ,In vitro ,Leukemia, Lymphoid ,Rats ,medicine.anatomical_structure ,chemistry ,Immunology ,Autoradiography ,RNA ,medicine.symptom ,Thymidine ,Intracellular ,Subcellular Fractions - Abstract
In vitro labelling of lymphocytes by RNA precursors is a useful tool to study the characteristics of normal and leukaemic cell populations. Basic conditions have been studied for in vitro labelling and indicated a desired level of cell concentration (2 × 104 to 2 × 105) and temperature (37° C). Normal leukocytes showed a fairly constant behaviour with respect to total uptake of radioactivity, incorporation into intracellular fractions and the ratio of 3H-cytidine to 3H-uridine incorporation (average ratio 10 ± 1). In contrast, the blood lymphocytes of patients with chronic lymphocytic leukaemia (CLL) exhibited a great variation in the parameters studied, ranging from below normal to several times normal values. This broad spectrum of in vitro characteristics has to be taken into consideration when populations of CLL lymphocytes are compared to normal lymphocytes and to those of other lymphatic disorders.
- Published
- 2009
34. Ansätze für eine Bifurkationsanalyse von RF LC-Tank VCOs unter Berücksichtigung nichtlinearer Bauelementegleichungen
- Author
-
J.-K. Bremer, Christoph Zorn, and Wolfgang Mathis
- Subjects
lcsh:TA1-2040 ,General Medicine ,lcsh:Engineering (General). Civil engineering (General) - Abstract
Es wird ein alternativer Ansatz zum Entwurf von vollintegrierten LC Oszillatoren mit Hilfe der Andronov-Hopf Bifurkationsanalyse unter Einbeziehung eines nichtlinearen Overall-Modells für MOS-Transistoren (EKV-Modell) vorgestellt. Das in dieser Arbeit vorgestellte Verfahren beschreibt die MOS-Kapazität des VCOs über geometrische Gundgrößen, die damit nur als Längen- und Weitenverhältnisse in die Bifurkationsanalyse eingehen. Zur Beschreibung der MOS-Kapazität wurde ein Basic-Charge-Modell, wie es in den Arbeiten von Enz und Vittoz vorgestellt wurde, in Verbindung einer expliziten analytischen Näherung des Oberflächenpotenzials verwendet. Das Verfahren ermöglicht es, als zusätzlichen Freiheitsgrad für den Designer auch die Amplitude zur Optimierung der Bauteilparameter heranzuziehen und vorab eine genauere Abschätzung der Parameter des Varaktors zu erhalten. Zusammengefasst in einer Toolbox führt die Anwendung des Verfahrens auf einen grafischen Optimierungsprozess, mit dessen Hilfe die Parameter analytisch bestimmt werden können. Die verwendete Methode erweitert den von Hajimiri und Ham vorgestellten Entwurfsprozess von LC-Tank VCOs um eine Stabilitätsanalyse, die Berücksichtigung harmonischer höherer Ordnung und die physikalisch exakte Modellierung der Varaktorkapazitäten.
- Published
- 2008
35. Nichtlineare Rauschmodellierung von LC Tank VCOs
- Author
-
J.-K. Bremer, Wolfgang Mathis, and Tina Thiessen
- Subjects
lcsh:TA1-2040 ,General Medicine ,lcsh:Engineering (General). Civil engineering (General) - Abstract
Im Rahmen dieser Arbeit wird ein alternativer Ansatz zur Phasenrauschoptimierung von LC-Tank Oszillatoren (VCOs) unter Verwendung stochastischer Differentialgleichungen vorgestellt. Zunächst werden die linearen Ansätze von Leeson, Hajimiri und Lee analysiert und bewertet. Danach wird ein Konzept vorgestellt, mit dem man die Rauscheigenschaften von VCOs auf der Grundlage stochastischer Differentialgleichungen und Fokker-Planck-Gleichungen untersuchen kann. Ziel dieser Arbeit ist eine Beschreibung des Phasenrauschens auf der Basis einer nichtlinearen Rauschmodellierung, welche Parameter eines VCOs für eine Optimierung beinhaltet. Es wurde ein Matlab-Tool erstellt und die Funktionalität anhand von Simulationen verifiziert.
- Published
- 2008
36. Chemotherapeutische Behandlungsmöglichkeiten bei fortgeschrittenen Sarkomen
- Author
-
Ch. Schmidt, M. Higi, W. Bierbaum, N. Firusian, Norbert Niederle, M. E. Scheulen, Seeber S, and K. Bremer
- Subjects
Oncology ,Cisplatin ,medicine.medical_specialty ,Vincristine ,Chemotherapy ,Ifosfamide ,business.industry ,medicine.medical_treatment ,Soft tissue ,General Medicine ,medicine.disease ,Radiation therapy ,Internal medicine ,medicine ,Doxorubicin ,Sarcoma ,business ,medicine.drug - Abstract
43 patients with metastasizing sarcomas were treated with a combination of either vincristin, adriamycin and cis-platinum (n = 21) or ifosfamide and cis-platinum at three weeks' intervals in each case. Ten patients responded to the first combination and nine to the second combination with objective tumor regression. Particularly the latter result is remarkable since 16 of the 22 patients had already been pretreated with combinations containing adriamycin. Obviously the combination of ifosfamide and cis-platinum is a promising alternative in metastasizing sarcomas of the bones and soft tissue, especially if the CYVADIC combination--which is often regarded as standard treatment--remained unsuccessful. This has no bearing on additional surgical measures or on radiotherapy which may be necessary in some patients.
- Published
- 2008
37. Vergleich der antiemetischen Wirksamkeit von Granisetron und Alizaprid plus Dexamethason bei Zytostatikatherapie
- Author
-
R. Uhlenbusch and K. Bremer
- Subjects
Chemotherapy ,Ifosfamide ,business.industry ,medicine.drug_class ,Nausea ,medicine.medical_treatment ,General Medicine ,Granisetron ,Anesthesia ,medicine ,Vomiting ,Antiemetic ,Alizapride ,medicine.symptom ,business ,Dexamethasone ,medicine.drug - Abstract
In a randomized single-blind international multicentre trial, two antiemetic regimens were compared in 115 oncology patients undergoing chemotherapy for the first time (cisplatin greater than 15 mg/m2, or ifosfamide greater than 1200 mg/m2 or etoposide greater than 120 mg/m2). One group received granisetron, a 5-hydroxytryptamine type-3-receptor antagonist, 40 micrograms/kg alone intravenously before chemotherapy, with, if necessary, up to two further doses daily of 40 micrograms/kg. The second group received a combination of alizapride plus dexamethasone (4 mg/kg alizapride and 8 mg/kg dexamethasone before chemotherapy, repeated, if necessary, after 4 and 8 hours up to two additional doses). There was good antiemetic efficacy (a maximum of one episode of vomiting in 24 hours = "major efficacy") in 50 of 62 patients (80.7%) in the granisetron group, and in 37 out of 53 (69.8%) of those treated with alizapride and dexamethasone; failure of antiemetic therapy occurred in 4.8% (granisetron) and 15.1% (combination) of patients. For the first day of each 5-day chemotherapy cycle, there was a higher rate of excellent antiemetic efficacy (no or only mild nausea, and no vomiting) with granisetron (90.3% vs 69.8%, P less than 0.006). The frequency (29% vs 32%) and nature of side effects (obstipation, diarrhoea, headaches, anxiety, vertigo), the causes of which were not differentiated, were similar. No extrapyramidal reactions occurred with granisetron. Of the 62 patients treated with granisetron, 47 did not require any further granisetron after the single daily prophylactic dose.
- Published
- 2008
38. 'Theologisch-polemisch-poetische Sachen'
- Author
-
K. Bremer and C. Spoerhase
- Published
- 2015
39. Das Verhalten nanostrukturierter Schaltungen unter der Berücksichtigung von Quanteneffekten
- Author
-
Wolfgang Mathis, J.-K. Bremer, M. Begoin, and F. Felgenhauer
- Subjects
lcsh:TA1-2040 ,General Medicine ,lcsh:Engineering (General). Civil engineering (General) - Abstract
Aufgrund der Bedeutung der MOS-Technologie für Halbleiterindustrie und deren fortschreitende Miniaturisierung ist es wichtig sicherzustellen, dass die klassischen Schaltungskonzepte für stark skalierte Bauelemente nicht ihre Gültigkeit verlieren. Ziel unserer Arbeitsgruppe ist es ein Simulatorpaket zu entwickeln, welches von einer physikalischen Sicht heraus quantenmechanische Einflüsse in integrierten Schaltungen ermittelt und Konsequenzen für zukünftiges Schaltungsdesign prognostiziert. Zur Berechnung und Modellierung der Quanteneffekte wird ein auf dem "non equilibrium Green's functions" (NEGF) Formalismus basierender numerischer 1-dimensionaler Simulator entwickelt. Auf der Basis von numerischen Transportsimulationen werden Ersatzschaltbilder für die SPICE Simulationsumgebung erstellt, um den Einfluss der Quanteneffekte in die Schaltungssimulation einzubinden. In this paper we discuss the expected impact of quantum effects in nanostructured CMOS circuits. In order to describe transport in mesoscopic electronic systems our group develops a 1-d numerical simulation packet based on the "non equilibrium Green's functions" (NEGF) formalism. By means of the obtained simulation results we develop extended SPICE circuit models. With these SPICE models the influence of quantum effects to the functionality of classical circuit concepts can be studied. Using these results it is our intention to develop circuits with a higher robustness against these quantum effects. For the illustration of our simulation concept we discuss some results of some circuit examples.
- Published
- 2006
40. Bendamustine, vincristine and prednisone (BOP) versus cyclophosphamide, vincristine and prednisone (COP) in advanced indolent non-Hodgkin’s lymphoma and mantle cell lymphoma: results of a randomised phase III trial (OSHO# 19)
- Author
-
K. Bremer, P. Richter, Andreas Schwarzer, Chr. Müller, Rita Pasold, Manfred Schulze, Dietger Niederwieser, Chr. Klinkenstein, Klaus Dachselt, J. Weniger, C. Boewer, H. Arzberger, Mathias Freund, Antje Schulze, Cornelia Winkelmann, C. A. Müller, Veronika Schirmer, B. Ismer, Hans-Joerg Fricke, A. Franke, S. Hahnfeld, and Michael Herold
- Subjects
Adult ,Male ,Bendamustine ,Cancer Research ,medicine.medical_specialty ,Vincristine ,Cyclophosphamide ,Follicular lymphoma ,Lymphoma, Mantle-Cell ,Gastroenterology ,Disease-Free Survival ,Lymphoplasmacytic Lymphoma ,Prednisone ,hemic and lymphatic diseases ,Internal medicine ,Antineoplastic Combined Chemotherapy Protocols ,medicine ,Bendamustine Hydrochloride ,Humans ,Lymphoma, Follicular ,Aged ,business.industry ,Lymphoma, Non-Hodgkin ,General Medicine ,Middle Aged ,medicine.disease ,Leukemia, Lymphocytic, Chronic, B-Cell ,Survival Analysis ,Surgery ,Non-Hodgkin's lymphoma ,Treatment Outcome ,Oncology ,Nitrogen Mustard Compounds ,Female ,Mantle cell lymphoma ,business ,medicine.drug - Abstract
Purpose: The purpose of this study was to compare the efficacy and toxicity of bendamustine, vincristine + prednisone (BOP) with a standard regimen of cyclophosphamide, vincristine + prednisone (COP) in patients with previously untreated advanced indolent non-Hodgkin’s lymphoma (NHL) and mantle cell lymphoma. Methods: A total of 164 patients with follicular lymphoma (grade 1/2), mantle cell lymphoma or lymphoplasmacytic lymphoma (immunocytoma) was randomised to treatment with vincristine 2 mg (day 1) and prednisone 100 mg/m2 (days 1–5) + bendamustine 60 mg/m2 (days 1–5) or + cyclophosphamide 400 mg/m2 (days 1–5) for a total of eight 21-day cycles. Results: The rate of complete remission was 22% with BOP and 20% with COP. The projected 5-year survival rate was 61% with BOP and 46% with COP. The BOP-associated 5-year survival advantage almost reached significance in the subgroup of patients who responded to therapy (74% vs. 56%; P=0.05), and did reach significance in responders who did not receive interferon maintenance therapy (70% vs. 47%; P=0.03). Toxicity was acceptable in both treatment groups, although alopecia and leucopenia were more severe with COP. Conclusions: Bendamustine can efficaciously and safely replace cyclophosphamide, as used in standard COP therapy, for the treatment of patients with indolent NHL and mantle cell lymphoma. Long-term survival data suggest a clinically significant benefit for patients treated with BOP
- Published
- 2005
41. Unalarmed interruption of continuous drug infusion by Perfusor Space GC syringe pumps
- Author
-
Felix Schmid, K. Bremer, Matthias S. Goepfert, and D.A. Reuter
- Subjects
Syringe driver ,business.industry ,Syringes ,Drug infusion ,Equipment failure ,Anesthesiology and Pain Medicine ,Anesthesia ,Anesthesia, Intravenous ,Humans ,Medicine ,Equipment Failure ,Infusions, Intravenous ,business ,Propofol ,Anesthetics, Intravenous ,Infusion Pumps ,Syringe - Published
- 2013
42. Systematik, Didaktik und Evaluation von Anästhesie-Simulationsszenarien
- Author
-
Daniel Frings, Kai Jensen, Axel Nierhaus, J. Schulte am Esch, Kamayni Agarwal, H.-J. Bartz, and K. Bremer
- Subjects
Anesthesiology and Pain Medicine ,Emergency Medicine ,General Medicine ,Critical Care and Intensive Care Medicine - Published
- 2004
43. Dairy product consumption, dietary nutrient and energy density and associations with obesity in Australian adolescents
- Author
-
Lawrence J. Beilin, Trevor A. Mori, Wendy H. Oddy, Alexandra Bremner, Philippa Lyons-Wall, Therese A. O'Sullivan, Amanda Devine, Megan E Seares, and Helen K Bremer
- Subjects
Male ,medicine.medical_specialty ,Adolescent ,Medicine (miscellaneous) ,Overweight ,Weight Gain ,Body Mass Index ,Nutrient density ,Environmental health ,Internal medicine ,medicine ,Humans ,Obesity ,Pregnancy ,Nutrition and Dietetics ,business.industry ,Confounding ,Australia ,Feeding Behavior ,medicine.disease ,Diet ,Endocrinology ,Cross-Sectional Studies ,Cohort ,Female ,Dairy Products ,medicine.symptom ,business ,Energy Intake ,Body mass index ,Weight gain - Abstract
Background Dairy intake is likely to influence dietary energy density (ED) and nutrient density (ND), which are factors representing aspects of dietary quality. Although evidence suggests dairy intake is unlikely to contribute to obesity, intake tends to decrease over adolescence, potentially as a result of concerns around weight gain. We examined associations between dairy intake, ED and ND, and investigated relationships with obesity in adolescents. Methods The present study comprised a cross-sectional study of 1613 14-year-olds in the Western Australian Pregnancy Cohort (Raine) Study. Adolescents completed a 212-item food frequency questionnaire. Nutrient Rich Food index 9.3 (NRF9.3) was used to estimate ND. Age-specific body mass index (BMI) and waist–height cut-offs were used to categorise obesity risk. Results Mean (SD) dairy intake was: 2.62 (1.51) servings daily; ED was 4.53 (0.83) (food and beverage) and 6.28 (1.33) (food only); ND was 373 (109). Dairy intake was inversely associated with ED and positively associated with ND. The odds of being overweight (as assessed by BMI) increased by 1.24 (95% confidence interval = 1.09–1.42) with each 100-point increase in ND, after adjustment for potential confounders and energy intake. ED measures and dairy intake were inversely associated with obesity after adjustment for confounders; associations became nonsignificant after energy adjustment. Conclusions The NRF9.3 was originally designed to assess foods, not diets. Further research in other cohorts to determine whether similar findings exist, or investigations into alternate measures of dietary ND, may prove useful. Our findings may be the result of factors such as an excess consumption of refined but fortified foods. Although higher dairy intakes were associated with higher ND, intakes were not associated with higher obesity risk.
- Published
- 2014
44. Pilot Study of Whole-Body Hyperthermia Combined with Chemotherapy in Patients with Metastasised Pretreated Progressive Breast, Ovarian, and Colorectal Carcinomas
- Author
-
R. Lohmann, A. Meyer, and K. Bremer
- Subjects
Hyperthermia ,Oncology ,Chemotherapy ,medicine.medical_specialty ,business.industry ,medicine.medical_treatment ,Thermo chemotherapy ,medicine.disease ,Breast cancer ,Internal medicine ,medicine ,Ovarian carcinomas ,In patient ,business ,Whole body - Published
- 2001
45. Levonantradol bei der Behandlung von zytostatika-bedingter Übelkeit und Erbrechen: Klinische Erfahrungen
- Author
-
Ch. Schmidt, Seeber S, G. Schmitt, M. Higi, K. Bremer, and N. Niederle
- Subjects
Levonantradol ,Nausea ,business.industry ,Anesthesia ,Cytostatic drugs ,medicine ,Vomiting ,General Medicine ,medicine.symptom ,business ,medicine.drug - Published
- 2008
46. Analysis of the Characteristics of PVA-Coated LPG-Based Sensors to Coating Thickness and Changes in the External Refractive Index
- Author
-
Lourdes S. M. Alwis, Kenneth T. V. Grattan, K. Bremer, and Tong Sun
- Subjects
Materials science ,Optical fiber ,Thin layers ,business.industry ,Optical power ,engineering.material ,Grating ,Cladding (fiber optics) ,law.invention ,Optics ,Coating ,law ,engineering ,Electrical and Electronic Engineering ,Composite material ,business ,QA ,Instrumentation ,Diffraction grating ,Refractive index - Abstract
Recent research has shown that the transmission spectrum of a long period grating (LPG) written into an optical fiber is sensitive to the thickness and the refractive index (RI) of a thin layer deposited on it, a concept which forms the basis of a number of optical fiber sensors. The research reported herein is focused, in particular, on sensors of this type to create a design with an optimized thickness of the deposited layers of polyvinyl alcohol (PVA) on LPGs forming the basis of a highly sensitive probe. In creating such sensors, the dip-coating technique is used to minimize deleterious effects in the attenuation bands resulting from the inhomogeneity of the coated surface. In this paper, LPGs with different coating thicknesses are uniformly coated with thin layers of PVA and submerged in oils of known RI over the range from 1.30 to 1.70, to create effective RI probes. It is observed that when the coating thickness reaches a particular value that enables a substantial redistribution of the optical power within the overlay, a maximum sensitivity of the sensor can be achieved, even when the overlay has a RI higher than that of the cladding. The experimental results obtained through the characterization of the devices developed are shown to be in good agreement with the results of a theoretical model.
- Published
- 2013
47. Comparison of the Clinical Relevance of CEA, CA 15-3 and MCA in Breast Cancer
- Author
-
G. Bremer, K. Bremer, S. Micus, and A. Eberhard
- Subjects
Cancer Research ,medicine.medical_specialty ,Pathology ,Receiver operating characteristic ,business.industry ,Clinical course ,CA 15-3 ,Hematology ,Serum concentration ,medicine.disease ,Gastroenterology ,Breast cancer ,Oncology ,Internal medicine ,medicine ,Clinical significance ,Enzyme immunoassays ,business ,Tumor marker - Abstract
Background: Tumor marker determinations are helpful parameters in the control and follow-up of the clinical course of neoplastic diseases. The serum concentrations of the three tumor markers CEA, CA 15-3 and MCA have been evaluated to comparatively investigate their clinical relevance in breast cancer patients. Patients and Methods: Simultaneous determinations of the serum concentrations of the three tumor markers CEA, CA 15-3 and MCA were performed in 419 sequential breast cancer patients. CEA and MCA were determined by means of enzyme immunoassays and CA 15-3 by a radio-immunoassay. Results: The serum concentrations of all three tumor markers correlate with tumor activity and tumor mass. The receiver operating characteristics (ROC) curves show that CA 15-3 has the greatest sensitivity and specificity. All three tumor markers did not reveal any dependence on age, but on the location of metastases; the median serum values decrease in the following sequence: osseous, visceral, and soft-tissue metastases. With a combination of tumor markers, the gain in sensitivity is associated with a loss of specificity, the combination of CEA + CA 15-3 appears to be the most favorable one. The combination of all three tumor markers does not show any advantage over the double combination CEA + CA 15-3. Conclusions: CA 15-3 has the highest sensitivity and specificity. As a combination of tumor markers CA 15-3 + CEA is recommended in breast cancer patients.
- Published
- 1996
48. Randomisation und Patientenaufklärung
- Author
-
B. Wiedenmann, A. Harstrick, G. Bremer, Michael Pfreundschuh, D. Sorger, Hans Scherübl, E. Heidemann, A. Resch-Holeczke, M. Korn, F. Riesen, A.W. Wassner, F. Walter, H.J. Weh, M. Rohrbacher, U. Haverkamp, S. Faiss, D. Depisch, E.-O. Riecken, Christoph Renner, Dirk Strumberg, B. Marian, Michael Hejna, T. Schenk, de Wit, Werner Scheithauer, M. Karall, H. Ofner, T. Zimmer, R. Pötter, Gabriela Kornek, Siegfried Seeber, C. Zornig, Joachim Baumgart, A. Eberhard, Heinz Ludwig, D.K. Hossfeld, H. Engler, Rainer Preiss, M. Schönfelder, Wilfried Eberhardt, Frank Hartmann, Hansjochen Wilke, M.E. Scheulen, U. Klaassen, R. Schmidt, G. Salem, S. Micus, Beat Thürlimann, and K. Bremer
- Subjects
Cancer Research ,Oncology ,Hematology - Published
- 1996
49. Cosmogenic nuclides in differentiated antarctic meteorites: measurements and model calculations
- Author
-
Hansjakob Hofmann, H.-J. Lange, K. Bremer, Martin Suter, Rainer Wieler, S. Vogt, Rolf Michel, and U. Herpers
- Subjects
Isotopes of calcium ,Nuclear physics ,Radionuclide ,Meteorite ,Space and Planetary Science ,Mineralogy ,Environmental science ,Astronomy and Astrophysics ,Context (language use) ,Neutron activation analysis ,Cosmogenic nuclide ,Mass spectrometry ,Accelerator mass spectrometry - Abstract
The cosmogenic radionuclides 10Be, 26Al and 53Mn and stable He-, Ne- and Ar-isotopes were measured in differentiated meteorites from Antarctica using accelerator mass spectrometry, γ-γ-coincidence techniques, radiochemical neutron activation analysis and conventional mass spectrometry. No depth effects were seen in meteorites from which several samples were analyzed. In most of the meteorites 10Be and 26Al were in saturation at time of fall, but the 26Al concentrations are partially lowered by substantial terrestrial ages. For 10Be some extremely low concentrations were found which cannot be explained by the decay during terrestrial residence. The experimental data are discussed together with rare gas measurements in the context of model calculations of the depth- and size-dependent production of cosmogenic nuclides in differentiated stony meteorites. Based on the model calculations minimal exposure ages, 21 Ne 53 Mn and shielding corrected 21Ne exposure ages were calculated. A detailed discussion of the production rates and of possible pairing of meteorites is given.
- Published
- 1995
50. Phase II Study of Subcutaneous Erythropoietin for Treatment of Myelodysplastic Syndromes (FAB Type I and II): A Trial of the Phase l/ll Study Group of the Association for Medical Oncology of the German Cancer Society
- Author
-
G. Hartung, U. Essers, O. Quarder, M.E. Heim, S. Öhl, M. Baldus, K. Bremer, D. Fritze, Dieter Hoelzer, W. Queißer, A. Weigold, and Lutz Edler
- Subjects
Ineffective erythropoiesis ,Oncology ,Cancer Research ,medicine.medical_specialty ,business.industry ,Anemia ,Myelodysplastic syndromes ,Cancer ,Phases of clinical research ,Hematology ,medicine.disease ,medicine.disease_cause ,Erythropoietin ,hemic and lymphatic diseases ,Internal medicine ,Refractory anemia with ring sideroblasts ,medicine ,In patient ,business ,medicine.drug - Abstract
Background : Anemia in patients with myelodysplastic syndromes (MDS) is usually put down to ineffective erythropoiesis, although the contributory role of other mechanisms has not bee
- Published
- 1995
Catalog
Discovery Service for Jio Institute Digital Library
For full access to our library's resources, please sign in.