WorldWideScience

Sample records for fibrillation integration einer

  1. Integration of cardiac computed tomography into pulmonary vein isolation in patients with paroxysmal atrial fibrillation; Integration einer praeinterventionellen Computertomografie des Herzens in die therapeutische Pulmonalvenenisolation bei Patienten mit paroxysmalem Vorhofflimmern

    Energy Technology Data Exchange (ETDEWEB)

    Weber, T.F. [Abt. Radiologie, Deutsches Krebsforschungszentrum, Heidelberg (Germany); Klemm, H.; Willems, S. [Klinik und Poliklinik fuer Kardiologie und Angiologie, Universitaetsklinikum Hamburg-Eppendorf (Germany); Koops, A.; Adam, G.; Begemann, P.G. [Klinik und Poliklinik fuer Diagnostische und Interventionelle Radiologie, Universitaetsklinikum Hamburg-Eppendorf (Germany); Nagel, H.D. [Philips Medizin Systeme GmbH, Hamburg (Germany)

    2007-12-15

    Purpose: Detailed anatomic information of the left atrium is necessary for securely performing radiofrequency ablation of atrial fibrillation-triggering ectopies in the pulmonary vein ostia. In this study the impact of a preinterventionally acquired cardiac computed tomography (CT) on pulmonary vein isolation (PVI) was assessed. Materials and methods: Examinations of 54 patients with paroxysmal atrial fibrillation undergoing PVI were analyzed. In 27 patients a supplementary cardiac CT was obtained prior to PVI (CT group, 12 women, 15 men, 59.7 {+-} 9.9 years of age): 16 x 1.5 mm collimation, 0.2 pitch, 120 kV tube voltage, 400 effective mAs. The fluoroscopy time, effective dose and quantity of radiofrequency (RF) pulses of the following catheter ablation were compared to 27 patients undergoing stand-alone PVI (11 women, 16 men, 62.0 {+-} 9.9 years of age). Mann-Whitney tests served for statistical comparison. Results: CT datasets were successfully integrated into the ablation procedure of each patient in the CT group. The mean quantity of RF pulses was significantly lower in the CT group (22.1 {+-} 8.0 vs. 29.1 {+-} 11.9, p = 0.030), and a significant reduction of fluoroscopy time was found (41.8 {+-} 12.0 min vs. 51.2 {+-} 16.0 min, p = 0.005). Effective doses of the catheter ablation differed in an equivalent dimension but altogether not significantly (14.9 {+-} 10.0 mSv vs. 20.0 {+-} 16.0 mSv, p = 0.203). The mean additive effective dose of the cardiac CT was 85 {+-} 0.3 mSv. (orig.)

  2. An Integrated Management Approach to Atrial Fibrillation.

    Science.gov (United States)

    Carter, Lindsey; Gardner, Martin; Magee, Kirk; Fearon, Ann; Morgulis, Inna; Doucette, Steve; Sapp, John L; Gray, Chris; Abdelwahab, Amir; Parkash, Ratika

    2016-01-25

    Atrial fibrillation (AF) is the most common sustained cardiac arrhythmia resulting in mortality and morbidity. Gaps in oral anticoagulation and education of patients regarding AF have been identified as areas that require improvement. A before-and-after study of 433 patients with newly diagnosed AF in the 3 emergency departments in Nova Scotia from January 1, 2011 until January 31, 2014 was performed. The "before" phase underwent the usual-care pathway for AF management; the "after" phase was enrolled in a nurse-run, physician-supervised AF clinic. The primary outcome was a composite of death, cardiovascular hospitalization, and AF-related emergency department visits. A propensity analysis was performed to account for differences in baseline characteristics. A total of 185 patients were enrolled into the usual-care group, and 228 patients were enrolled in the AF clinic group. The mean age was 64±15 years and 44% were women. In a propensity-matched analysis, the primary outcome occurred in 44 (26.2%) patients in the usual-care group and 29 (17.3%) patients in the AF clinic group (odds ratio 0.71; 95% CI [0.59, 1]; P=0.049) at 12 months. Prescription of oral anticoagulation was increased in the CHADS2 ≥2 group (88.4% in the AF clinic versus 58.5% in the usual-care group, Pmanagement approach for the burgeoning population of AF may provide an overall benefit to cardiovascular morbidity and mortality. © 2016 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley Blackwell.

  3. [Manfred Schneider. Lübeck im 12. und 13. Jahrhundert. Archäologische Befunde zur entstehung einer mittelalterlichen Grossstadt. In : Expansion - integration? Danish-Baltic Contacts 1147-1410] / Dennis Hortmuth

    Index Scriptorium Estoniae

    Hortmuth, Dennis

    2011-01-01

    Arvustus:Manfred Schneider. Lübeck im 12. und 13. Jahrhundert. Archäologische Befunde zur entstehung einer mittelalterlichen Grossstadt. In : Expansion - integration? Danish-Baltic Contacts 1147-1410 AD. (Vordingborg, 2009).

  4. [Manfred Schneider. Lübeck im 12. und 13. Jahrhundert. Archäologische Befunde zur entstehung einer mittelalterlichen Grossstadt. In : Expansion - integration? Danish-Baltic Contacts 1147-1410] / Dennis Hortmuth

    Index Scriptorium Estoniae

    Hortmuth, Dennis

    2011-01-01

    Arvustus:Manfred Schneider. Lübeck im 12. und 13. Jahrhundert. Archäologische Befunde zur entstehung einer mittelalterlichen Grossstadt. In : Expansion - integration? Danish-Baltic Contacts 1147-1410 AD. (Vordingborg, 2009).

  5. Integration einer OSCE in das zahnmedizinische Physikum [Integration of an Objective Structured Clinical Examination (OSCE into the Dental Preliminary Exams

    Directory of Open Access Journals (Sweden)

    Ratzmann, Anja

    2012-02-01

    , speziellen problemorientierten Seminaren und dem ärztlichen Kommunikationstraining. Die wesentliche Zielstellung besteht darin, den Studierenden bereits zu Beginn des Zahnmedizinstudiums einen realen Patientenkontakt zu ermöglichen und somit das Studium frühzeitig patientennah zu gestalten. Die Studierenden trainieren das Erheben einer umfangreichen Anamnese sowie die klinische Befundung.Methode: Der Kurs wird im Rahmen des zahnmedizinischen Physikums anhand eines OSCE an einem standardisierten Patienten überprüft. Das OSCE bestand aus den drei Stationen: Anamnesegespräch, Zahnstatus und Mundhygienestatus.Ziel: Es wurde der Mehrwert eines zusätzlichen Trainings (Anamnesedurchführung und klinische Untersuchung in Vorbereitung auf die OSCE- Prüfung untersucht. Dazu wurden die Prüfungsleistungen einer Gruppe ohne Training (Kontrollgruppe und einer Gruppe mit Training (Interventionsgruppe verglichen.Ergebnisse: Die Interventionsgruppe war in folgenden Items signifikant besser als die Kontrollgruppe: in der erreichten Gesamtpunktzahl für das OSCE- Früher Patientenkontakt, sowie in den wichtigsten Punkten der Anamnese und der klinischen Untersuchung. Tendenziell zeigte die Experimentalgruppe zusätzlich bezüglich des Items „Mundhygienestatus“ höhere Rangwerte.Schlussfolgerung: In der vorliegenden Untersuchung konnte der positiver Effekt eines zusätzlichen Trainings auf die Prüfungsleistung im OSCE gezeigt werden. Unter Berücksichtigung der Limitation der Studie und der Ergebnisse des Literaturstudiums empfiehlt sich aus unserer Sicht die Durchführung eines solchen Trainings zur Vorbereitung auf die OSCE- Prüfung.

  6. Astrophysik Spuren einer Sternenexplosion

    Science.gov (United States)

    Knie, Klaus

    2005-01-01

    Münchner Physikern ist es gelungen, mit einem Tandembeschleuniger radioaktive 60Fe-Atome in einer Tiefseeprobe nachzuweisen. Wahrscheinlich wurde dieser radioaktive Stoff vor drei Millionen Jahren von einer etwa hundert Lichtjahre entfernten Supernova erzeugt, durch das Weltall geschleudert und schließlich auf der Erde abgelagert.

  7. [Managing the atrial fibrillation process: an integral approach].

    Science.gov (United States)

    Palacio Lapuente, F; Hernandez Galindo, M; Amezqueta Goñi, C; Lapuente Heppe, I; Sola Saravia, C

    2013-01-01

    The study was developed in 3 phases, with the following aims: To define the most appropriate management process for atrial fibrillation (AF) from the point of view of the health professionals and the patients. To determine how it is managed in daily practice. To identify the changes required in order that this daily practice may come closer to that of an appropriate management process. 1st phase: consensus techniques were used, as well as a failure modes and effects analysis (FMEA), and a focus group with patients. 2nd phase: included a questionnaire. 3rd phase: 3 nominal groups and 3 focus groups were formed. Primary Care and Cardiology. Family doctors, cardiologists, and patients, in the first phase, and family doctors in the second and third phases. 1st phase: a flow diagram was designed with its explanatory notes on the correct care process for AF. 2nd phase: how AF was managed in current practice. 3rd phase: barriers for using the correct care process were identified, and proposals for their improvement were defined. Almost 40% of the family doctors were involved in the diagnosis and treatment of their patients with FA. Training, cooperation between specialties, motivation, working in a team with nursing, and organisational changes were identified as essential factors for a proper management process. AF can be managed from Primary Care. To do this, important changes are required in the care organisation. Training, along with support and communication between care levels are also seen as necessary. Copyright © 2012 SECA. Published by Elsevier Espana. All rights reserved.

  8. Integration einer Stromerzeugung aus Windenergie und Speichersystemen unter besonderer Berücksichtigung von Druckluft-Speicherkraftwerken

    OpenAIRE

    Kruck, Christoph

    2008-01-01

    Die Stromerzeugung aus Windenergie hat in den vergangenen Jahren, insbesondere unterstützt durch das Erneuerbare-Energien-Gesetz (EEG), stark zugenommen und belief sich im Jahr 2006 auf einen Anteil von rund 4,8 % an der Bruttostromerzeugung. Aufgrund des fluktuierenden Charakters der Windstromerzeugung ist die Integration und Einspeisung dieses Anteils in das Netz der öffentlichen Versorgung bereits heute mit teilweise erheblichen Problemen verbunden. Diese werden sich in Zukunft weiter v...

  9. Architecture of a fully integrated communication infrastructure for the smart home; Architektur einer vollintegrierten Kommunikationsinfrastruktur fuer das Smart Home

    Energy Technology Data Exchange (ETDEWEB)

    Schaefer, Falk-Moritz; Kays, Ruediger [TU Dortmund (Germany). Lehrstuhl fuer Kommunikationstechnik

    2012-07-01

    For some time, applications in the areas of home automation, ambient assisted living and e-health are discussed. These require reliable and energy-efficient communication solutions in the home environment. In addition, new concepts that go hand in hand with the concept of the smart grids need an access to devices within the home environment. In the realization of smart homes the diversity of market participants involved, the parallel existing business models, the application requirements and the available communication systems make special demands on the underlying network infrastructure. Different solutions should be able to communicate with each other and compatible. In addition, the user expects a simple operation and configuration as well as a long-term support of the products. In the best case, the user is confronted with a single, integrated network infrastructure. Instead of separate systems for reading out of smart meters for monitoring the solar system, for health monitoring and the settings of multimedia devices, the telephone system, or computer network, a fully integrated smart home communications infrastructure should come into operation. This smart home infrastructure should be free of unnecessary duplication of structures; all equipment should be taken into account with a communication interface. The authors of the contribution under consideration report on a possible architecture of such a network infrastructure. Different grades are identified. A protocol stack for different technologies and the linking of different network hierarchies are described.

  10. Advantages of horizontal and vertical integration in process- and switch gear control; Vorteile einer horizontalen und vertikalen Integration in Prozess- und Schaltanlagenautomatisierung

    Energy Technology Data Exchange (ETDEWEB)

    Erning, Peter; Langlotz, Kati [ABB AG, Mannheim (Germany). Div. Energietechnik

    2010-07-01

    Higher operating efficiency in power generation is more and more in the focus. Traditional control systems are frequently confined to the vertical integration of process control. It is quite common to use separate SCADA systems for controlling electrical auxiliary systems. However, there exists an overlap between these domains: major loads though belonging to the process are operated by medium-voltage switch gear. Until now the necessary control interconnections required the installation of costly and inflexible marshalling racks. Integrated operation and diagnostics was difficult to implement. These disadvantages apply accordingly in case of implementation of the entire sub-station via direct wiring. State-of-the-art control systems connect these two worlds in one system by integration of sub-station automation using the open standard IEC 61850 which allows freedom of choice in equipment and full access to all sub-station data. (orig.)

  11. Chances for the further integration of decentralized generation by following a grid-driven approach; Moeglichkeiten einer netzorientierten Betriebsweise zur weiteren Integration dezentraler Energieumwandlung auf Verteilnetzebene

    Energy Technology Data Exchange (ETDEWEB)

    Luensdorf, Ontje [OFFIS Oldenburg (Germany); Sonnenschein, Michael [Oldenburg Univ. (Germany); Mohrmann, Michael; Hofmann, Lutz [Hannover Univ. (Germany). IEH FG EE; Gronstedt, Phillip; Kurrat, Michael [TU Braunschweig (Germany). elenia

    2011-07-01

    The integration of renewable energy generation facilities increases the decentralization of electricity supply as well as feed-in fluctuations. Due to grid stability concerns, the integration capability of distribution grids is limited. The Energy Research Alliance of Lower Saxony (FEN) has developed the grid-driven operation mode, which can be used to reduce the feed-in fluctuations by increasing the flexibility of electricity generation, consumption and storage. This article presents simulation results of the grid-driven operation mode in distribution grids with high penetrations of distributed energy generation facilities. (orig.)

  12. Integrated approach to treatment-resistant atrial fibrillation: additional value of acupuncture

    OpenAIRE

    Jonkman, F A M; Jonkman-Buidin, M L

    2013-01-01

    A 62-year-old patient with chronic bronchitis had treatment-resistant atrial fibrillation. Electrical cardioversion was performed, but sinus rhythm (SR) lasted only for some minutes. Administration of amiodarone was withheld in favour of a course of acupuncture treatment in order to increase the success rate of a second attempt of electrical cardioversion. After two acupuncture treatments, spontaneous conversion to SR occurred. Relapses into atrial fibrillation in the following five winters, ...

  13. Integrating genetic, transcriptional, and functional analyses to identify 5 novel genes for atrial fibrillation

    DEFF Research Database (Denmark)

    Sinner, Moritz F; Tucker, Nathan R; Lunetta, Kathryn L

    2014-01-01

    BACKGROUND: Atrial fibrillation (AF) affects >30 million individuals worldwide and is associated with an increased risk of stroke, heart failure, and death. AF is highly heritable, yet the genetic basis for the arrhythmia remains incompletely understood. METHODS AND RESULTS: To identify new AF-re...

  14. Atrial fibrillation

    African Journals Online (AJOL)

    ABEOLUGBENGAS

    patients with atrial fibrillation managed in a referral hospital in Port Harcourt, southern Nigeria. ... treatment despite all the patients having moderate to high risk of stroke ... Keywords: Atrial fibrillation, thrombosis, CHADS2 Score, stroke risk, ...

  15. Risikowahrnehmung einer aufstrebenden Technologie: Wasserstoffenergie

    OpenAIRE

    Flynn, Rob; Bellaby, Paul; Ricci, Miriam

    2006-01-01

    Obwohl Wasserstoff schon seit langer Zeit in der Industrie genutzt wird, ist seine Verwendung als Treibstoff oder Energieträger relativ neu, und das Expertenwissen über die damit einhergehenden Risiken ist weder vollständig noch einhellig. Dementsprechend existiert auch wenig Wissen über die öffentliche Wahrnehmung der Wasserstoffenergie und die Einstellungen bezüglich einer möglichen kommerziellen Nutzung. Der vorliegende Artikel beginnt mit der Diskussion unterschiedlicher Risikodefinitione...

  16. The effect of integrated cardiac rehabilitation versus treatment as usual for atrial fibrillation patients treated with ablation: the randomised CopenHeartRFA trial protocol

    Science.gov (United States)

    Risom, Signe Stelling; Zwisler, Ann-Dorth Olsen; Rasmussen, Trine Bernholdt; Sibilitz, Kirstine Lærum; Svendsen, Jesper Hastrup; Gluud, Christian; Hansen, Jane Lindschou; Winkel, Per; Thygesen, Lau Caspar; Perhonen, Merja; Hansen, Jim; Dunbar, Sandra B; Berg, Selina Kikkenborg

    2013-01-01

    Introduction Atrial fibrillation affects almost 2% of the population in the Western world. To preserve sinus rhythm, ablation is undertaken in symptomatic patients. Observational studies show that patients with atrial fibrillation often report a low quality of life and are less prone to be physically active due to fear of triggering fibrillation. Small trials indicate that exercise training has a positive effect on exercise capacity and mental health, and both patients with recurrent atrial fibrillation and in sinus rhythm may benefit from rehabilitation in managing life after ablation. No randomised trials have been published on cardiac rehabilitation for atrial fibrillation patients treated with ablation that includes exercise and psychoeducational components. Aim To test the effects of an integrated cardiac rehabilitation programme versus treatment as usual for patients with atrial fibrillation treated with ablation. Methods and analysis design The trial is a multicentre parallel arm design with 1:1 randomisation to the intervention and control group with blinded outcome assessment. 210 patients treated for atrial fibrillation with radiofrequency ablation will be included. The intervention consists of a rehabilitation programme including four psychoeducative consultations with a specially trained nurse and 12 weeks of individualised exercise training, plus the standard medical follow-up. Patients in the control group will receive the standard medical follow-up. The primary outcome measure is exercise capacity measured by the VO2 peak. The secondary outcome measure is self-rated mental health measured by the Short Form 36 questionnaire. Postintervention, qualitative interviews will be conducted in 10% of the intervention group. Ethics and dissemination The protocol is approved by the regional research ethics committee (number H-1-2011-135), the Danish Data Protection Agency (reg. nr. 2007-58-0015) and follows the latest version of the Declaration of Helsinki

  17. Sterbenlassen. Vom Ende einer Psychotherapie

    OpenAIRE

    Ranefeld, Johannes

    2001-01-01

    Reflexionen zum Ende einer psychoanalytischen Psychotherapie; ein Ende, an das es sich nur zögernd und ausweichend annähern läßt. Sterben ist letztendlich ein einsames Geschäft, wir halten den Tod für ansteckend und verfahren nach der Regel: "Man darf nicht zulassen, daß er einem ins Gesicht atmet" (Michael Connelly 1996, The Poet). Dennoch wird ver­sucht, beschreibend ein Konzept der Annäherungen zu skizzieren.

  18. Development of a 5 kW fuel cell APU with integrated Diesel reformer; Entwicklung einer 5 kW Brennstoffzellen-APU mit integriertem Diesel-Reformer

    Energy Technology Data Exchange (ETDEWEB)

    Womann, M.; Weinert, R.; Garcia, P. (Tenneco - Heinrich Gillet GmbH, Edenkoben)

    2008-07-01

    Fuel cell systems have great potential to play a key role in our everyday life. Especially in mobile applications, fuel cells will help to increase system efficiencies, to avoid the release of greenhouse gases and to move to a future sustainable mobility. While fuel cell propulsion systems offer great mid- and long-term perspectives, Fuel Cell Auxiliary Power Units (APU) have a real chance to reduce fuel consumption and pollution within the next years by offering an alternative to truck idling. One of the most promising technologies for APUs are PEM (Proton Exchange Membrane) fuel cell systems that are running on diesel reformate. This technology is supported by the European Commission's Sixth Framework Program. Part of this program is the HyTRAN project. 19 partners under the lead of the VOLVO Technology Corporation are developing two innovative, fully integrated and compact fuel cell systems. An important outcome from the project is a complete Fuel Cell APU that uses newly developed components like fuel processor and air compressor. The system was first integrated virtually with CATIA V5. Modular build-up, material, space frame, insulation, system simulations and pressure drop calculations were important issues that had to be worked on. Based on the virtual study, a prototype of the system has been built that will be tested in the next step. (orig.)

  19. Migrationstheoretische Gesellschaftskritik. Versuch einer Standortbestimmung

    Directory of Open Access Journals (Sweden)

    Radostin Kaloianov

    2014-05-01

    Full Text Available Der Aufsatz versucht eine kritisch-theoretische Position für Migrant_innen und zu den Themen der Migration zu erarbeiten und dabei zwei Aufgaben zu lösen. Die politische Aufgabe, Kritik und Migration ins Verhältnis zu setzen, ergibt sich daraus, dass aktuell Kritik und Migration weit auseinanderliegen und aus mehrheitlicher Sicht gar nicht zusammengehören. Das politische Vorhaben der Untersuchung geht in den wissenschaftlichen Auftrag über, herauszufinden, welche der gegenwärtig verfügbaren und einflussreichen Optionen theoretischer Gesellschaftskritik die Herausbildung einer kritisch-theoretischen Position für Migrant_innen in der Sozialforschung befördern bzw. bremsen könnten. Die Lösung dieser beiden Aufgaben zeichnet die Kritikposition von Migrant_innen als eine weitgehend ,atopische‘. 

  20. Inspection programme for checking the integrity of the production pipes of a gas storage cavern; Untersuchungsprogramm zur Ueberpruefung der Integritaet der Produktionsrohrtour einer Erdgasspeicherkaverne

    Energy Technology Data Exchange (ETDEWEB)

    Nickel, F. [Untergrundspeicher- und Geotechnologie-Systeme GmbH, Mittenwalde (Germany); Arnold, C. [VNG Verbundnetz Gas AG, Leipzig (Germany)

    2007-09-13

    In autumn 2005, a novelty project was initiated in a storage cavern of VNG - Verbundnetz Gas AG. The storage cavern had been operated for 25 years, and the piping had to be exchanged. Load tests and gas tightness tests were carried out. A pressure gradient was obtained for which there were no geomechanical reasons, i.e. there was no reliable information on the pressure resistance of the cover rock. In an extensive test programme carried out for the first time in a storage cavern, the integrity of the gas well was proved. High safety requirements were set during operations as all work had to be carried out above a gas-filled cavern. The complexity of the task both permitted and necessitated the planning and implementation of a complex test programme comprising many new features. The work was carried out successfully in cooperation with the responsible licensing authorities, the Sachsen-Anhalt mines inspectorate, and the Environmental Office of the State of Sachsen at Halle/Saale. (orig.)

  1. Eumelanin fibrils

    Science.gov (United States)

    McQueenie, Ross; Sutter, Jens; Karolin, Jan; Birch, David J. S.

    2012-07-01

    We describe the auto-oxidation of 3, 4-dihydroxy-L-phenylalanine (L-DOPA) in the synthesis of eumelanin to spontaneously produce fibrils upon drying. The self-assembled fibrils are of characteristic diameter ~1 to 2 μm, composed of filaments, and are unidirectional, apart from branches that are formed at typically an angle of 20 to 22 deg. The fibrils are characterized using fluorescence spectroscopy, fluorescence decay times, scanning electron microscopy, atomic force microscopy, and fluorescence lifetime imaging microscopy. The fibrils mimic natural melanin in consisting of core eumelanin with efficient nonradiative properties, but they also display pockets of electronically isolated species with higher radiative rates on the nanosecond timescale. Eumelanin fibrils formed occasionally in solution are tentatively attributed to a scaffold of bacteria or fungus. Fabricating and characterizing novel synthetic eumelanin structures such as fibrils are of interest in helping to reveal a functional structure for eumelanin, in understanding its photophysics, in learning more about L-DOPA as it is used in the treatment of Parkinson's disease, and in producing novel materials which might embody some of the diverse properties of eumelanin.

  2. Mobile Health Technology for Atrial Fibrillation Management Integrating Decision Support, Education, and Patient Involvement: mAF App Trial.

    Science.gov (United States)

    Guo, Yutao; Chen, Yundai; Lane, Deirdre A; Liu, Lihong; Wang, Yutang; Lip, Gregory Y H

    2017-08-26

    Mobile Health technology for the management of patients with atrial fibrillation is unknown. The simple mobile AF (mAF) App was designed to incorporate clinical decision-support tools (CHA2DS2-VASc [Congestive heart failure, Hypertension, Age ≥75 years, Diabetes Mellitus, Prior Stroke or TIA, Vascular disease, Age 65-74 years, Sex category], HAS-BLED [Hypertension, Abnormal renal/liver function, Stroke, Bleeding history or predisposition, Labile INR, Elderly, Drugs/alcohol concomitantly], SAMe-TT2R2 [Sex, Age App vs usual care) in a cluster randomized design pilot study. Patients' knowledge, quality of life, drug adherence, and anticoagulation satisfaction were evaluated at baseline, 1 month, and 3 months. Usability, feasibility, and acceptability of the mAF App were assessed at 1 month. A total of 113 patients were randomized to mAF App intervention (mean age, 67.4 years; 57.5% were male; mean follow-up, 69 days), and 96 patients were randomized to usual care (mean age, 70.9 years; 55.2% were male; mean follow-up, 95 days). More than 90% of patients reported that the mAF App was easy, user-friendly, helpful, and associated with significant improvements in knowledge compared with the usual care arm (P values for trend App versus usual care (all P App arm versus usual care, with anxiety and depression reduced (all P App, integrating clinical decision support,education, and patient-involvement strategies, significantly improved knowledge, drug adherence, quality of life, and anticoagulation satisfaction. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

  3. Atrial fibrillation

    DEFF Research Database (Denmark)

    Lip, Gregory Y H; Fauchier, Laurent; Freedman, Saul B;

    2016-01-01

    Atrial fibrillation (AF) is the most common sustained cardiac rhythm disorder, and increases in prevalence with increasing age and the number of cardiovascular comorbidities. AF is characterized by a rapid and irregular heartbeat that can be asymptomatic or lead to symptoms such as palpitations...

  4. Atrial fibrillation

    DEFF Research Database (Denmark)

    Olesen, Morten S; Nielsen, Morten W; Haunsø, Stig;

    2014-01-01

    Atrial fibrillation (AF) is the most common cardiac arrhythmia affecting 1-2% of the general population. A number of studies have demonstrated that AF, and in particular lone AF, has a substantial genetic component. Monogenic mutations in lone and familial AF, although rare, have been recognized...

  5. Atrial Fibrillation.

    Science.gov (United States)

    Zimetbaum, Peter

    2017-03-07

    This issue provides a clinical overview of atrial fibrillation, focusing on diagnosis, treatment, and practice improvement. The content of In the Clinic is drawn from the clinical information and education resources of the American College of Physicians (ACP), including MKSAP (Medical Knowledge and Self-Assessment Program). Annals of Internal Medicine editors develop In the Clinic in collaboration with the ACP's Medical Education and Publishing divisions and with the assistance of additional science writers and physician writers.

  6. Ueber das Zirkulationssystem einer Machilde (Thysanura

    Directory of Open Access Journals (Sweden)

    Rudolf Barth

    1963-08-01

    Full Text Available Es werden Anatomie und Histologie des Zirkulations- und Bingegewebssytems der letzten Segmente und der Schwanzanhaenge einer nicht naeher bestimmten Machilide beschrieben. Es ergeben sich folgende Hauptergebnisse: a - Das Bindegewebssystem hat eine ausgedehnt Entwicklung erfahren und schliesst, abgesehen vom Respirationssystem und den Lymphzellen, alle Organe gegen die Lymphfluessigkeit des Mixocoels ab ("Diffusionsbarrieren". Es wird der mixocoelomiale Raum dem intracoelomialen gegenueber gestellt. Dieser schliesst die Mehrzahl der Organe in sich ein und erfaehrt im aeussersten Ende des Abdomens (etwa vom Anus ab und in den Schwanzanhaengen eine ausgedehnte Entwicklung. Abdomenende und Anhaenge werden durch eine mesodermale Quermembran gegen den mixocoelomialen Raum abgeschlossen. b - Das Zirkulationssystem besteht im hinterem Koerperteis aus dem Rueckengefaess, das sich bis zur Quermembran fortsetzt und vor dieser ein Rueckstromventil und eine Filterregion besitzt, durch die keine Lymphzellen hindurchfliessen koennen, - ferner aus einem Terminalgefaess, das in Fortsetzung des Rueckengefaesses das Terminalfilum bis zum Ende durchlaeuft; hier muendet es in den intracoelomialen Raum. Ausserdem besitzt jeder Cercus ein Gefaess, das an der Quermembran mit einer ein Ventil tragenden Oeffnung beginnt und an der Spitze des Cercus sich ebenfalls oeffnet. Es hat seitliche Eintrittsoeffnungen und Bindegewebsbaender, durch die waehrend der Pulsation des Rueckengefaesses der Querschnitt veraendert wird. Der Zirkulationsweg geht aus der Figur 4 hervor. Terminalgefaess und Cercusgefaesse haben keine Muskelelemente. Die Cercusgefaesse treten nicht mit dem Rueckengefaess in Verbindung. C - Die Lymphfluessigkeit des mixocoelomialen Raumes hat eine andere Zusammensetzung als die des Raumes hinter der Quermembran. d - Das Rueckengefaess besteht aus einer inneren Muskularis, die gegen das Gefaesslumen durch das Sarkolemm abgeschlossen ist, und aus einer

  7. Can we improve the early detection of atrial fibrillation in a stroke unit? Detection rate of a monitor with integrated detection software.

    Science.gov (United States)

    Arevalo-Manso, Juan Jose; Martínez-Sánchez, Patricia; Fuentes, Blanca; Ruiz-Ares, Gerardo; Sanz-Cuesta, Borja Enrique; Prefasi, Daniel; Juarez-Martin, Belén; Navarro-Parias, Azahara; Parrilla-Novo, Pilar; Diez-Tejedor, Exuperio

    2016-02-01

    It is unknown whether monitors that include atrial fibrillation recognition software (AF-RS) increase the rate of early atrial fibrillation (AF) detection in acute stroke. We aimed to evaluate the AF detection rate of an AF-RS monitor and compare it with standard monitoring. This was a retrospective, single-centre observational study conducted on consecutive patients with acute transient ischaemic attack or brain infarction attended in a stroke unit (SU) with six beds. Five beds had a standard monitor with a three-lead electrocardiogram (ECG)-tracing monitor that did not automatically detect AF, and one bed had a 12-lead ECG monitor with integrated AF-RS. All patients were monitored for at least 24 h and underwent a daily ECG during their stay in the SU. In case of unknown stroke aetiology, the patients underwent 24 h Holter monitoring. A total of 76 patients were included: 59 patients in the standard monitor group and 17 patients in the AF-RS monitor group. The mean age was 72.11 (±13.09) years, and 59.2% were men. A total of 20 new cases of AF were identified. The AF-RS monitor showed a higher rate of AF detection than the standard devices (57.1% vs 7.7%, p=0.031). The AF-RS monitor showed sensitivity, specificity, positive predictive value, and negative predictive values of 57.1%, 100%, 100% and 76.9%, respectively. For the standard monitors, these values were 7.7%, 100%, 100% and 79.3%, respectively. The monitor with AF-RS demonstrated a higher detection rate for AF than standard ECG monitoring in acute stroke patients in a SU. © The European Society of Cardiology 2014.

  8. Amyloid Fibril Solubility

    CERN Document Server

    Rizzi, L G

    2015-01-01

    It is well established that amyloid fibril solubility is protein specific, but how solubility depends on the interactions between the fibril building blocks is not clear. Here we use a simple protein model and perform Monte Carlo simulations to directly measure the solubility of amyloid fibrils as a function of the interaction between the fibril building blocks. Our simulations confirms that the fibril solubility depends on the fibril thickness and that the relationship between the interactions and the solubility can be described by a simple analytical formula. The results presented in this study reveal general rules how side-chain side-chain interactions, backbone hydrogen bonding and temperature affect amyloid fibril solubility, which might prove a powerful tool to design protein fibrils with desired solubility and aggregation properties in general.

  9. Haptische Modellierung und Deformation einer Kugelzelle

    Science.gov (United States)

    Schippritt, Darius; Wiemann, Martin; Lipinski, Hans-Gerd

    Haptische Simulationsmodelle dienen in der Medizin in erster Linie dem Training operativer Eingriffe. Sie basieren zumeist auf physikalischen Gewebemodellen, welche eine sehr genaue Simulation der biomechanischen Eigenschaften des betreffenden Gewebes erlauben, aber gleichzeitig sehr rechenintensiv und damit zeitaufwändig in der Ausführung sind. Die menschliche Wahrnehmung kann allerdings auch eine ungenaue haptische Modellierung psychooptisch ausgleichen. Daher kann es sinnvoll sein, haptische Simulationen auch mit nicht vollständig physikalisch definierten Deformationsmodellen durchzuführen. Am Beispiel der haptischer Simulation einer in-vitro Fertilisation wird gezeigt, dass durch die Anwendung eines geometrischen Deformationsmodells eine künstliche Befruchtung unter realistischen experimentellen Bedingungen in Echtzeit haptisch simuliert und damit trainiert werden kann.

  10. "AderCast" - Podcasting an einer Hauptschule

    Directory of Open Access Journals (Sweden)

    Felix Studencki

    2011-03-01

    Full Text Available Ein bisschen mehr als ein Jahr ist es her, seitdem die erste Sendung auf unserem Schulpodcast „AderCast“ ausgestrahlt wurde. Seitdem ist viel geschehen, wir haben ständig weiter produziert und sind um 14 Sendungen und um Einiges an Erfahrung reicher. Das Podcastprojekt an unserer Schule steckt jedoch noch in den Kinderschuhen. Wir entdecken mit jeder weiteren Sendung neue Möglichkeiten, Podcasts sinnvoll einzusetzen. Die Schule, der Unterricht und die Umgebung der SchülerInnen bringen uns immer wieder auf neue spannende Ideen. Oder hätten Sie schon von einer Sendung über ein Tagebuch eines Goldfisches gehört? Falls es Sie interessiert, können Sie es bald auf unserem Podcast anhören.

  11. Atrial fibrillation.

    Science.gov (United States)

    Bang, Casper N

    2013-10-01

    Atrial fibrillation (AF) is a common complication after myocardial infarction (MI) and new-onset AF has been demonstrated to be associated with adverse outcome and a large excess risk of death in both MI and aortic stenosis (AS) patients. Prevention of new-onset AF is therefore a potential therapeutic target in AS and MI patients. Lipid-lowering drugs, particularly statins, have anti-inflammatory and antioxidant properties that may prevent AF. Accordingly, statins are recommended as a class IIa recommendation for prevention of new-onset AF after coronary artery bypass grafting (CABG). However, this preventive effect has not been investigated on new-onset AF in asymptomatic patients with AS or a large scale first-time MI patient sample and data in patients not undergoing invasive cardiac interventions are limited. This PhD thesis was conducted at the Heart Centre, Rigshospitalet, Denmark, with the aim to investigate the three aforementioned questions and to add to the existing evidence of AF prevention with statins. This was done using three different settings: 1) a randomized patients sample of 1,873 from the Simvastatin and Ezetimibe in Aortic Stenosis (SEAS) study, 2) a register patient sample of 97,499 with first-time MI, and 3) all published studies until beginning of June 2011 examining statin treatment on new-onset and recurrent AF in patients not undergoing cardiac surgery. This thesis revealed that statins did not lower the incidence or the time to new-onset AF in patients with asymptomatic AS. However, statin treatment showed an independently preventive effect on new-onset AF, including type-dependent effect and a trend to dosage-dependent effect. In addition, this thesis showed that good compliance to statin treatment was important to prevent new-onset AF. Finally, the meta-analysis in this PhD thesis showed a preventive effect in the observational studies although this effect was absent in the randomized controlled trials. Based on this PhD thesis

  12. Zur konkreten Utopie einer kritischen Universität

    Directory of Open Access Journals (Sweden)

    ­ Kollektiv

    2016-11-01

    Full Text Available Wie wollen wir im akademischen Kontext arbeiten, in welchen Verhältnissen und zu welchen Themen? Unsere Vorschläge für eine gründliche Umgestaltung der Universität haben wir auf der Grundlage einer kritischen Bestandsaufnahme des Arbeitens und Lernens an deutschen Universitäten erarbeitet. Dies geschah im Rahmen einer von s u b \\ u r b a n initiierten Zukunftswerkstatt „Konkrete Utopie einer kritischen Wissensproduktion“, die am 30. April 2016 im Atelier des ISR an der TU Berlin mit zehn Teilnehmer_innen stattfand. In diesem Text stellen wir die Ergebnisse der Zukunftswerkstatt vor.

  13. To arrange the window - the creation of an integrated local view on information diversity / Das Fenster zur Information gestalten - die Schaffung einer integrierten lokalen Sicht auf die Vielfalt von Informationsressourcen

    Directory of Open Access Journals (Sweden)

    Nunnenmacher, Lothar

    2006-01-01

    Full Text Available The way our patrons search and use information resources has already changed substantially, but the shift to new technologies is not yet completed. Currently new information is mostly coming via "the screen", at least in the STM disciplines (science, technology, medicine. The challenge for libraries nowadays is, to arrange the window towards the bulk of available information according to the needs of different users. Several measures of integration are needed to achieve this aim: * Instead of supplying the information physically, we now have to provide quick access to different information systems, as far as possible integrated, and to enhance these systems with local enrichments (e.g. availability, local views or filters. * Beyond journal articles and books we have to integrate other media like photos, videos, or even scientific data. Moreover, the scientific and scholarly information is going to change the media format from paper to electronics, which we should take into consideration in our efforts. * We have to appreciate that library services are just a small contribution to the whole environment of learning, teaching or research at university. People should be served according to their needs with all resources in an integrated way instead of splitting them up into small partitions based on organisational units. To arrange the window means to integrate the necessary resources in a way that as much information as possible is included, but guidance and filtering tools avoid information overload. Based on a model to group information hierarchically a draft for an integrated “Search Centre” is presented.

  14. Qualitative Inhaltsanalyse – Versuch einer Begriffsbestimmung und Systematisierung

    OpenAIRE

    Stamann, Christoph; Janssen, Markus; Schreier, Margrit

    2016-01-01

    Unter der Bezeichnung qualitative Inhaltsanalyse findet sich in wissenschaftlichen Publikationen eine Vielfalt an Vorgehensweisen. Mit dieser Vielfalt, die wir in der Anzahl inhaltsanalytischer Verfahren und ihrer je forschungsspezifischen Modifikation begründet sehen, geht die Notwendigkeit einer Systematisierung einher. In unserem Beitrag nähern wir uns zunächst einer Definition von Inhaltsanalyse an, deren Kern wir in der Systematisierung und Interpretation von Inhalten sehen. Davon ausgeh...

  15. Etablierung und Charakterisierung einer Kokultur equiner endometrialer Epithel- und Stromazellen

    OpenAIRE

    2016-01-01

    Ziel dieser Studie war die Etablierung einer Kokultur aus equinen endometrialen Epithel- und Stromazellen. Nach der erfolgreichen Umsetzung des Kokulturmodells sollte im weiteren Versuchsablauf durch die Zugabe von 17β-Östradiol (E2) und/oder Progesteron (P4) zum Nährmedium der Einfluss der Hormone auf die Zellen untersucht werden. Neben einer lichtmikroskopischen Auswertung der zytomorphologischen Charakteristika beider Zellarten sollte die Expression der Steroidhormonrezeptoren Östrogenr...

  16. Atrial Ectopics Precipitating Atrial Fibrillation

    OpenAIRE

    Johnson Francis

    2015-01-01

    Holter monitor tracing showing blocked atrial ectopics and atrial ectopic precipitating atrial fibrillation is being demonstrated. Initially it was coarse atrial fibrillation, which rapidly degenerated into fine atrial fibrillation.

  17. Vulnerability to ventricular fibrillation

    Science.gov (United States)

    Janse, Michiel J.

    1998-03-01

    One of the factors that favors the development of ventricular fibrillation is an increase in the dispersion of refractoriness. Experiments will be described in which an increase in dispersion in the recovery of excitability was determined during brief episodes of enhanced sympathetic nerve activity, known to increase the risk of fibrillation. Whereas in the normal heart ventricular fibrillation can be induced by a strong electrical shock, a premature stimulus of moderate intensity only induces fibrillation in the presence of regional ischemia, which greatly increases the dispersion of refractoriness. One factor that is of importance for the transition of reentrant ventricular tachycardia to ventricular fibrillation during acute regional ischemia is the subendocardial Purkinje system. After selective destruction of the Purkinje network by lugol, reentrant tachycardias still develop in the ischemic region, but they do not degenerate into fibrillation. Finally, attempts were made to determine the minimal mass of thin ventricular myocardium required to sustain fibrillation induced by burst pacing. This was done by freezing of subendocardial and midmural layers. The rim of surviving epicardial muscle had to be larger than 20 g. Extracellular electrograms during fibrillation in both the intact and the "frozen" left ventricle were indistinguishable, but activation patterns were markedly different. In the intact ventricle epicardial activation was compatible with multiple wavelet reentry, in the "frozen" heart a single, or at most two wandering reentrant waves were seen.

  18. Amyloid Fibrils from Hemoglobin

    Directory of Open Access Journals (Sweden)

    Nadishka Jayawardena

    2017-04-01

    Full Text Available Amyloid fibrils are a class of insoluble protein nanofibers that are formed via the self-assembly of a wide range of peptides and proteins. They are increasingly exploited for a broad range of applications in bionanotechnology, such as biosensing and drug delivery, as nanowires, hydrogels, and thin films. Amyloid fibrils have been prepared from many proteins, but there has been no definitive characterization of amyloid fibrils from hemoglobin to date. Here, nanofiber formation was carried out under denaturing conditions using solutions of apo-hemoglobin extracted from bovine waste blood. A characteristic amyloid fibril morphology was confirmed by transmission electron microscopy (TEM and atomic force microscopy (AFM, with mean fibril dimensions of approximately 5 nm diameter and up to several microns in length. The thioflavin T assay confirmed the presence of β-sheet structures in apo-hemoglobin fibrils, and X-ray fiber diffraction showed the characteristic amyloid cross-β quaternary structure. Apo-hemoglobin nanofibers demonstrated high stability over a range of temperatures (−20 to 80 °C and pHs (2–10, and were stable in the presence of organic solvents and trypsin, confirming their potential as nanomaterials with versatile applications. This study conclusively demonstrates the formation of amyloid fibrils from hemoglobin for the first time, and also introduces a cost-effective method for amyloid fibril manufacture using meat industry by-products.

  19. Dynamics of Focal Fibrillation Waves during Persistent Atrial Fibrillation.

    Science.gov (United States)

    Lanters, Eva A H; Allessie, Maurits A; DE Groot, Natasja M S

    2016-04-01

    The incidence and appearance of focal fibrillation waves on the right and left atrial epicardial surface were visualized during 10 seconds of persistent atrial fibrillation in a 71-year-old woman with valvular heart disease. The frequent, nonrepetitive, widespread, and capricious distribution of focal waves suggests that transmural conduction of fibrillation waves is most likely the mechanism underlying focal fibrillation waves.

  20. Tratamento operatório da fibrilação atrial: revisão integrativa da literatura Surgical treatment of atrial fibrillation: integrative review

    Directory of Open Access Journals (Sweden)

    João Roberto Breda

    2011-09-01

    Full Text Available A fibrilação atrial (FA no pré-operatório de operações cardíacas abertas, incluindo revascularização cirúrgica do miocárdio (RCM e operações valvares, representa fator de risco independente para eventos cardíacos maiores e redução de sobrevida. Devido à complexidade do assunto, principalmente na avaliação das taxas de sucesso, foi proposta recentemente uma declaração de consenso pela International Society of Minimally Invasive Cardiothoracic Surgery (ISMICS, com o intuito de determinar se a ablação operatória da FA promove resultados clínicos favoráveis em pacientes submetidos a outras operações cardíacas na comparação com operações isoladas sem ablação. O objetivo deste trabalho é apresentar dados da literatura que possam contribuir para o consenso sobre o tratamento operatório da FA e ser utilizado como fonte de atualização. A metodologia envolveu revisão integrativa da literatura, com análise e síntese dos dados obtidos de forma descritiva, apresentando o conhecimento atual sobre o tema apresentadoWhen atrial fibrillation (AF is present in pre-operative open heart surgeries, including coronary artery bypass grafting and valve operations, it represents an independent risk factor for cardiac events and reduced survival. Due to the complexity of the subject, especially when evaluating success rates (reversion and maintenance of normal sinus rhythm, a consensus statement was recently proposed by the International Society of Minimally Invasive Cardiothoracic Surgery (ISMICS, in order to determine whether the intraoperative ablation of AF promotes favorable clinical outcomes in patients undergoing other cardiac operations in comparison with individual operations without ablation. The aim of this paper is to present published data which has contributed to consensus statement and can be useful as update source. The integrative review was the methodology that provides synthesis of knowledge and applicability

  1. Ideen zu einer Literatursoziologie des Internets. Mit einer Blogotop-Analyse

    Directory of Open Access Journals (Sweden)

    Peer Trilcke

    2013-11-01

    Full Text Available Der Essay skizziert und exemplifiziert die Möglichkeiten einer Literatursoziologie des Internets und plädiert in diesem Zusammenhang für eine Empirisierung der Forschung zu diesem rasant wachsenden, jedoch bisher in seiner Differenziertheit allenfalls oberflächlich beschriebenen Feld der Kommunikation über Literatur. Hierzu werden die literaturwissenschaftlichen Internet Studies und ihr literatursoziologischer Teilbereich innerhalb der allgemeinen Digital Humanities verortet. Als Beispiel für eine in diesem Sinne relational-empirische Literatursoziologie des Internets werden erste Ergebnisse der Analyse eines sog. Bücherblogotops präsentiert, anhand derer sich einige Mechanismen der sekundären literarischen Kommunikation zwar nicht repräsentativ, aber doch exemplarisch diskutieren lassen.

  2. Graffiti als ,doing Illegalityʼ. Perspektiven einer Cultural Criminology

    Directory of Open Access Journals (Sweden)

    Sascha Schierz

    2014-10-01

    Full Text Available Auseinandersetzungen mit dem Thema Graffiti in der Stadt lassen sich seit einigen Jahren gehäuft in unterschiedlichen Diskurssträngen der Kriminologie oder aber Kriminalprävention auffinden. Sie gelten weitestgehend als Symbole für Kriminalität und werden mit Furcht assoziiert. Gleichzeitig wird ihnen in künstlerischen Events verstärkt die Bedeutung einer neuen Kunstform im öffentlichen Raum angetragen. Der Artikel untersucht im Sinne einer Cultural Criminology die Praktiken und Diskurse, die illegalen Graffiti in der Stadt eine Bedeutung zuweisen, wie die Praxis der Writer, sich zwischen diesen Bedeutungsräumen zu verorten.

  3. Surgery for atrial fibrillation.

    Science.gov (United States)

    Lawrance, Christopher P; Henn, Matthew C; Damiano, Ralph J

    2014-11-01

    Atrial fibrillation is the most common cardiac arrhythmia, and its treatment options include drug therapy or catheter-based or surgical interventions. The surgical treatment of atrial fibrillation has undergone multiple evolutions over the last several decades. The Cox-Maze procedure went on to become the gold standard for the surgical treatment of atrial fibrillation and is currently in its fourth iteration (Cox-Maze IV). This article reviews the indications and preoperative planning for performing a Cox-Maze IV procedure. This article also reviews the literature describing the surgical results for both approaches including comparisons of the Cox-Maze IV to the previous cut-and-sew method.

  4. Cryoballoon Catheter Ablation in Atrial Fibrillation

    Directory of Open Access Journals (Sweden)

    Cevher Ozcan

    2011-01-01

    Full Text Available Pulmonary vein isolation with catheter ablation is an effective treatment in patients with symptomatic atrial fibrillation refractory or intolerant to antiarrhythmic medications. The cryoballoon catheter was recently approved for this procedure. In this paper, the basics of cryothermal energy ablation are reviewed including its ability of creating homogenous lesion formation, minimal destruction to surrounding vasculature, preserved tissue integrity, and lower risk of thrombus formation. Also summarized here are the publications describing the clinical experience with the cryoballoon catheter ablation in both paroxysmal and persistent atrial fibrillation, its safety and efficacy, and discussions on the technical aspect of the cryoballoon ablation procedure.

  5. Elastic model for crimped collagen fibrils

    Science.gov (United States)

    Freed, Alan D.; Doehring, Todd C.

    2005-01-01

    A physiologic constitutive expression is presented in algorithmic format for the nonlinear elastic response of wavy collagen fibrils found in soft connective tissues. The model is based on the observation that crimped fibrils in a fascicle have a three-dimensional structure at the micron scale that we approximate as a helical spring. The symmetry of this wave form allows the force/displacement relationship derived from Castigliano's theorem to be solved in closed form: all integrals become analytic. Model predictions are in good agreement with experimental observations for mitral-valve chordae tendinece.

  6. What Is Atrial Fibrillation?

    Science.gov (United States)

    ... regular beat. Certain cells in your heart make electric signals that cause the heart to contract and pump ... read your ECG to find out if the electric signals are normal. In atrial fibrillation (AFib), the heart’s ...

  7. CRM - Grundlagen und Realisierung am Beispiel einer Standardanwendung

    OpenAIRE

    Weinmann, Dieter

    2002-01-01

    Bearbeitung der Grundlagen zu Datenbanken, DataWarehouse und CRM, sowohl hardware- als auch software-seitig. Beschreibung der Implementierung eines Siebel-Systems auf einer Oracle 8i-Datenbank nahe am Standard. Darauffolgender Vergleich von Siebel 2000 mit mySAP.com CRM

  8. CRM - Grundlagen und Realisierung am Beispiel einer Standardanwendung

    OpenAIRE

    2002-01-01

    Bearbeitung der Grundlagen zu Datenbanken, DataWarehouse und CRM, sowohl hardware- als auch software-seitig. Beschreibung der Implementierung eines Siebel-Systems auf einer Oracle 8i-Datenbank nahe am Standard. Darauffolgender Vergleich von Siebel 2000 mit mySAP.com CRM

  9. Kontextspezifische Positionierungen: Darstellung eines Forschungszugangs und einer Analysestrategie am Fallbeispiel einer Lehrkraft "mit Migrationshintergrund"

    Directory of Open Access Journals (Sweden)

    Vesna Varga

    2014-07-01

    Full Text Available In diesem Beitrag wird der von uns entwickelte Ansatz der kontextspezifischen Positionierungen als Forschungszugang und Analysestrategie qualitativer Migrationsforschung beschrieben. Theoretische und empirische Arbeiten betonen seit Längerem, dass migrationsbezogene Differenzsetzungen und Zugehörigkeitskonstruktionen als relational hergestellte und kontextspezifisch differierende soziale Phänomene betrachtet werden müssen. Dies erfordert eine systematische Analyse fluider, sozialer (migrationsbezogener Relationen im Hinblick auf die Spezifik der alltäglichen Kontexte, in denen sie hergestellt werden. Bislang steht eine solche Analyse allerdings noch weitgehend aus. Mit der Verknüpfung der Analyse von Positionierungen mit derjenigen der Kontexte, in denen Positionierungen in narrativen Erzählungen stehen, veranschaulicht der Beitrag eine Möglichkeit der methodischen Realisierung mittels der Grounded-Theory-Methodologie. Er verdeutlicht damit speziell auch Einsatzmöglichkeiten der Positionierungsanalyse, um diese stärker als bisher für die (deutschsprachige Migrationsforschung nutzbar zu machen. Das Vorgehen wird beispielhaft anhand der Analyse eines Interviews mit einer Lehrkraft mit zugeschriebenem Migrationshintergrund veranschaulicht. Die Analyse zeigt, wie migrationsbezogene (und weitere Selbst- und Fremdpositionierungen je nach Kontext variieren und welche Bedeutung Positionierungen innerhalb schulischer Dominanzordnungen und Hierarchien haben. URN: http://nbn-resolving.de/urn:nbn:de:0114-fqs140330

  10. Informatische Modellbildung als Dimension einer künstlerisch-technisch konzipierten Medienbildung

    Directory of Open Access Journals (Sweden)

    Daniela Reimann

    2017-04-01

    Full Text Available Heute sind nicht nur diverse gestaltungsbezogene Disziplinen gefragt, sich aktiv mit der Digitalisierung von Information und ihren Potentialen und Nebenwirkungen für Bildungsprozesse auseinander zu setzen. In Deutschland haben sich Technikdidaktik und informatische Bildung getrennt von Medienpädagogik und Mediendidaktik entwickelt und wurden entsprechend unabhängig voneinander betrieben. Dies gilt auch für die Ästhetische Bildung, die informatisch-technische Inhalte kaum je curricular in die Auseinandersetzung mit digitaler Medienkultur integriert hat, schon gar nicht systematisch. Im diesem Artikel wird, ausgehend vom Stand der Forschung (zur Integration informatischer Inhalte in die Medienbildung und den identifizierten Grundproblemen der Medienbildung zwecks Kompensation der Defizite, ein auf Gestaltung basierter Ansatz präsentiert, kontextualisiert und diskutiert, der Technikverständnis in ein Konzept integrierter Medienbildung einbezieht, dies als Bildungsziel im Sinne eines ganzheitlichen Verständnisses von Welt begreift und daher disziplinüberschreitend angelegt ist. Der Ansatz geht über technokratische Vorstellungen einer Technikdidaktik hinaus, die Medientechnologien isoliert von lebensbedeutsamen, ästhetisch-künstlerisch gestalteten Kontexten betrachtet und vermittelt. Im didaktischen Konzept werden die Grundlagen informatischer Modellbildung als relevante Teilbereiche einer zeitgemässen, am Subjekt orientierten, gleichermassen ästhetisch-künstlerisch und technisch-informatisch geprägten Medienbildung aufgewiesen, ihre pädagogischen Vorläufer, Forschungsprojekte und Nachbardisziplinen benannt sowie Ausblicke für eine zeitgemässe Medienbildung gegeben.

  11. Key points in a history of success; Stationen einer Erfolgsgeschichte

    Energy Technology Data Exchange (ETDEWEB)

    Harloff, B.; Seibold, D.

    2002-05-01

    With the new 211 model series, the 7th E-Class generation is being launched into the upper mid-class market segment, which it has characterized with values such as safety, comfort and length of service life. With the exception of the pre-war design, the Mercedes 170, the new model's predecessors will be honored with a journey in time through the key points in a history of success. (orig.) [German] Mit der neuen Baureihe 211 startet die siebte E-Klasse-Generation in das Marktsegment der oberen Mittelklasse, das sie durch Werte wie Sicherheit, Komfort und Langlebigkeit erfolgreich gepraegt hat. Von der Vorkriegskonstruktion - dem Mercedes 170 - abgesehen, sollen auf einer Zeitreise durch die Stationen einer Erfolgsgeschichte die Vorgaenger des neuen Modells gewuerdigt werden. (orig.)

  12. Qualitative Inhaltsanalyse – Versuch einer Begriffsbestimmung und Systematisierung

    Directory of Open Access Journals (Sweden)

    Christoph Stamann

    2016-09-01

    Full Text Available Unter der Bezeichnung qualitative Inhaltsanalyse findet sich in wissenschaftlichen Publikationen eine Vielfalt an Vorgehensweisen. Mit dieser Vielfalt, die wir in der Anzahl inhaltsanalytischer Verfahren und ihrer je forschungsspezifischen Modifikation begründet sehen, geht die Notwendigkeit einer Systematisierung einher. In unserem Beitrag nähern wir uns zunächst einer Definition von Inhaltsanalyse an, deren Kern wir in der Systematisierung und Interpretation von Inhalten sehen. Davon ausgehend stellen wir vier Bezugspunkte für eine erste Systematisierung dieser forschungspraktischen Vielfalt dar. In diesem Zusammenhang diskutieren wir offene Fragen zum Thema Kategorien, also jenem Instrument, welches im Zentrum aller Inhaltsanalysen steht. Im letzten Abschnitt werden die Ergebnisse der Auseinandersetzung zusammengefasst und forschungspraktische Ableitungen formuliert, die eine Orientierung im Forschungsprozess bieten. URN: http://nbn-resolving.de/urn:nbn:de:0114-fqs1603166

  13. Faszination einer Kindsmörderin. Medea im 20. Jahrhundert

    Directory of Open Access Journals (Sweden)

    Barbara Feichtinger

    2007-03-01

    Full Text Available Die Berliner Literaturwissenschaftlerin Inge Stephan interpretiert ein beeindruckendes Panorama von Medea-Bearbeitungen in Literatur, bildender Kunst, Film und Musik. Sie spürt in ihrem Buch zur Medea-Rezeption im 20. Jh. in höchst differenzierter und anregender Weise den vielfältigen künstlerischen Auseinandersetzungen der Moderne mit einer in vieler Hinsicht provozierenden Frauengestalt der Antike nach.

  14. Entwicklung einer Spurendriftkammer mit Mikrostreifenauslese für Schwerionenexperimente

    OpenAIRE

    Frankenfeld, Ulrich

    1996-01-01

    Im Rahmen dieser Arbeit wurde ein Prototyp einer Spurendriftkammer mit Mikrostreifenauslese, wie sie als hochauflösende Spurendetektoren in der Kern- und Teilchenphysik zum Einsatz kommen sollen, konstruiert und getestet. Besonderes Augenmerk lag hierbei auf der Signalform und -verteilung, sowie auf dem Langzeitverhalten. Für die verschiedenen Messungen dieser Arbeit wurden die Mikrostreifen-Gasdetektoren in ein Edelstahlrohr eingebaut, das mit einem Vakuumpumpen-System verbunden ist. Durch E...

  15. Empirische Analyse einer verdolmetschten Gerichtsverhandlung aus dem Slowenischen ins Deutsche

    Directory of Open Access Journals (Sweden)

    Lea Burjan

    2012-12-01

    Full Text Available Dieser Artikel befasst sich mit dem Diskurs in einer Gerichtsverhandlung mit verschiedensprachigen Parteien. Die übliche Konversation im Gerichtssaal findet in Form eines Dialogs statt, wobei die Strategie des Gespräches durch den Richter als Gesprächsmoderator determiniert wird. Die Interaktion im gedolmetschten Diskurs verläuft anders als im nicht gedolmetschten Diskurs. Bei gedolmetschten Verhandlungen übernimmt der Gerichtsdolmetscher, als ein Mittler in der Konversation, die verantwortungsvolle Aufgabe, die richterliche Strategie der Konversation, also den eigentlichen Verhandlungsablauf, sinngemäß und originaltreu in den zielsprachlichen Kontextzu transportieren. Meistert er seine Aufgabe, wird ein reibungsloser Kommunikationsablauf im Sinne der gegenseitigen Einflussnahme der jeweiligen Kommunikationsteilnehmer gewährleistet. Scheitert er bei seinem Vorhaben, so kommt es in der Kommunikation zu Störungen, die durch zusätzliche sprachliche Interventionen beseitigt werden müssen. Seine Tätigkeit wird determiniert und mitbeeinflusst von den Unterschieden in der Rechtsterminologie der beiden Sprachen (Sprachregister, von dem vorgegebenen Dolmetschmodus, und von der Gesprächsstrategie des Sprachmoderators. Somit ist das Ziel des vorliegenden Beitrags, anhand einer empirischen Analyse einer gedolmetschten Zeugenvernehmung herauszufinden, inwiefern es dem Gerichtsdolmetscher gelingt, den ausgangssprachlichen Diskurs originaltreu in die Zielsprache zu übertragen und auf welche Probleme er bei diesem Übertragungsprozess stößt. Der vorliegenden Untersuchung dienen die von den Gerichten veranlassten Audioaufnahmen von mündlichen Verhandlungen als Korpus.

  16. Stroke prevention in atrial fibrillation

    DEFF Research Database (Denmark)

    Freedman, Ben; Potpara, Tatjana S; Lip, Gregory Y H

    2016-01-01

    Atrial fibrillation is found in a third of all ischaemic strokes, even more after post-stroke atrial fibrillation monitoring. Data from stroke registries show that both unknown and untreated or under treated atrial fibrillation is responsible for most of these strokes, which are often fatal...... or debilitating. Most could be prevented if efforts were directed towards detection of atrial fibrillation before stroke occurs, through screening or case finding, and treatment of all patients with atrial fibrillation at increased risk of stroke with well-controlled vitamin K antagonists or non-vitamin K...

  17. Modulation of atrial fibrillation

    NARCIS (Netherlands)

    Geuzebroek, G.S.C.

    2013-01-01

    In this thesis we investigate the results of various surgical procedures for atrial fibrillation which have been performed in the last 2 decades in the Sint Antonius Hospital, Nieuwegein, The Netherlands. In the 1990s the classical Maze III procedure was the main surgical technique for drug-refracto

  18. Lesson Five Atrial fibrillation

    Institute of Scientific and Technical Information of China (English)

    鲁端; 吴文烈

    2003-01-01

    @@ Atrial fibrillation(AF) may occur in paroxysmaland persistent forms. It may be seen in normal subjects,particularly during emotional stress or follow-ing surgery,exercise, or acute alcoholic intoxication.It also may occur in patients with heart or lungdisease who develop acute hypoxia, hypercapnia,ormetabolic or hemodynamic derangements.

  19. Ergebnisse einer neuen Technik der Meatusplastik im Rahmen der geschlechtsangleichenden Operation von Mann zu Frau

    OpenAIRE

    Rossi Neto R; Hueppe P; Pelzer N; Rübben H; vom Dorp F

    2011-01-01

    In unserer Klinik stellt sich die Meatusstenose als die häufigste Komplikation nach einer geschlechtsangleichenden Operation mit ca. 40 % betroffenen Patientinnen dar, gefolgt von lokalen Wundheilungsstörungen (26 %) und Verengung des Introitus vaginalis mit 12 %. Die Hauptkomplikationen werden bei der zweiten Sitzung mit kleinen ästhetischen Korrekturen beseitigt. Trotz einer zweiten Korrektur besteht jedoch immer noch das Risiko (1520 %) der Entstehung einer Striktur der Anastomos...

  20. HYPERTHYROIDISM AND ATRIAL FIBRILLATION

    Directory of Open Access Journals (Sweden)

    I. M. Marusenko

    2017-01-01

    Full Text Available Review on a problem of the development of atrial fibrillation in patients with thyrotoxicosis is presented. Thyrotoxicosis is one of the most frequent endocrine diseases, conceding only to a diabetes mellitus. The most frequent reasons of hyperthyroidism are Graves’ disease and functional thyroid autonomy. The authors give an analysis of data on the cardiac effects of thyrotoxicosis, features of heart remodeling under the influence of thyroid hyperfunction, prevalence of atrial fibrillation in thyrotoxicosis, depending on age, as well as the possibility of restoring sinus rhythm in the combination of these diseases. Particular attention is paid to the effect on the heart of subclinical thyrotoxicosis, which is defined as a dysfunction of the thyroid gland, characterized by low serum concentration of thyrotropin, normal values of free thyroxine and free triiodothyronine. Subclinical hyperthyroidism is also capable of causing heart remodeling and diastolic dysfunction.Prevalence of thyrotoxicosis in elderly people is higher in areas of iodine deficiency; it is relevant for our country due to the large territory of iodine deficiency. In elderly patients, the cardiac effects of thyrotoxicosis prevail in the clinical picture, that makes it difficult to diagnose endocrine disorders, and correction of thyrotoxicosis is critically important for the successful control of the heart rhythm. The article also discusses the problem of thyrotoxic cardiomyopathy, caused by the toxic effect of excess thyroid hormones: features of this heart disorder, factors affecting its formation, clinical significance and contribution to the development of rhythm disturbances. The greatest significance is the development of atrial fibrillation as a result of thyrotox-icosis in older patients who already have various cardiovascular diseases.Atrial fibrillation is the most frequent heart rhythm disorder in thyrotoxicosis. The main cause of arrhythmia in hyperthyroidism is the

  1. Plattenepithelkarzinom in Verbindung mit einer roten Tätowierung.

    Science.gov (United States)

    Schmitz, Inge; Prymak, Oleg; Epple, Matthias; Ernert, Carsten; Tannapfel, Andrea

    2016-06-01

    Obwohl Tätowierungen in den letzten Jahren außerordentlich beliebt geworden sind, wurde in der Literatur bisher nur über wenige Fälle schwerer Reaktionen berichtet, die zu einer malignen Transformation führten. Dies steht im Kontrast zu der praktisch unüberschaubaren Zahl an Tätowierungen weltweit. Die Zusammensetzung der für Tätowierungen verwendeten Farbstoffe variiert stark, und selbst gleiche Farbtöne können unterschiedliche Komponenten enthalten. Das Ziel unserer Studie war es zu untersuchen, auf welche Weise Tätowierungen möglicherweise Hautkrebs auslösen können. Wir berichten über den seltenen Fall einer 24-jährigen Frau, bei der sich sieben Monate nachdem sie eine Tätowierung auf dem Fußrücken erhalten hatte in unmittelbarer Nähe des verwendeten roten Farbstoffs ein Plattenepithelkarzinom entwickelte. Die Komplikationen begannen mit einer unspezifischen Schwellung. Die Läsion wurde histologisch untersucht. Die Zusammensetzung des inkorporierten Farbstoffs wurde mittels Rasterelektronenmikroskopie in Kombination mit energiedispersiver Elementanalyse analysiert. Zur weiteren Charakterisierung wurden Thermogravimetrie und Pulverdiffraktometrie eingesetzt. Der Tätowierungsfarbstoff enthielt hauptsächlich Bariumsulfat; Spuren von Al, S, Ti, P, Mg und Cl ließen sich ebenfalls nachweisen. Bei der Analyse zeigten sich Pigmentgranula unterschiedlicher Größe. In seltenen Fällen kann Tätowierungstinte karzinogene Effekte haben, die multifaktoriell zu sein scheinen. © 2016 Deutsche Dermatologische Gesellschaft (DDG). Published by John Wiley & Sons Ltd.

  2. Organisierende Zentren am Beispiel einer Kampagne zum Nahverkehr in Kassel

    Directory of Open Access Journals (Sweden)

    Rothe Ecke Kassel

    2016-11-01

    Full Text Available Der Stadtteilladen „Rothe Ecke“ ist ein Ort der Basisorganisierung im ehemaligen Arbeiterviertel Rothenditmold in Kassel. Hier werden politische Initiativen rund um die Themen Armut, prekäre Lebensrealitäten, schikanöse Arbeitsbedingungen und Rassismus von denjenigen organisiert, die davon betroffen sind. Interessen werden gegenüber dem Jobcenter, Vermieter_innen, Vorgesetzten oder der Stadt kollektiv vertreten. Der Beitrag veranschaulicht die Arbeit der „Rothen Ecke“ anhand einer Kampagne gegen Kürzungen im öffentlichen Nahverkehr.

  3. Game-based Learning im Bildungskontext einer Hochschule. Ein Praxisbericht

    Directory of Open Access Journals (Sweden)

    Jochen Pfannstiel

    2009-04-01

    Full Text Available Das Fach Software-Engineering stellt Lernende und Lehrende gleichermassen vor eine grosse Herausforderung, da eine Vielzahl von abstrakten Methoden und Modellen zu erlernen sind. An der Hochschule Offenburg wurde das Lernspiel «Software Engineering in the Future» als Ergänzung zur Präsenzveranstaltung entwickelt. Die Studierenden sollen über das Lernspiel motiviert werden, sich mit der Thematik zu befassen, um dann in ansprechend gestalteten authentischen Szenarien einzelne Methoden zu erlernen und zu vertiefen. Der Artikel stellt die zentralen Aspekte der Spielentwicklung und Ergebnisse einer ersten Befragung der Studierenden vor.

  4. Lifestyle und Endometriose - Ergebnisse aus einer Fall-Kontroll-Studie

    OpenAIRE

    2011-01-01

    Zusammenfassung Hintergrund und Ziele Die heutige Medizin ermöglicht es die Symptome Endometriose erkrankter Frauen medikamentös oder chirurgisch zu lindern. Doch viele Patienten wollen sich in die Behandlung selbst einbringen und einen eigenen Beitrag zu ihrer Genesung leisten. Eine Möglichkeit für Patientinnen dies zu tun ist eine Änderung des Lifestyles. Ziel dieser Arbeit ist es, Unterschiede im Lifestyle erkrankter und gesunder Frauen in einer großen Fall Kontroll-Studie zu untersuchen. ...

  5. Religionenlernen im Ethikunterricht. Ein Versuch aus der Perspektive einer angewandten Religionswissenschaft.

    Directory of Open Access Journals (Sweden)

    Christian Feichtinger

    2014-07-01

    Full Text Available ENGLISH: The growing importance of ethics classes raises the question of positioning and methods of learning about (world religions in school. So far, a confessional religious education has covered other religious traditions, but now also curricula of ethics classes usually contain elements of religious studies. But how can religious knowledge be integrated sensibly in an otherwise philosophical- ethical education? Beyond that, do ethics classes in the sense of applied ethics need a more comprehensive understanding of religious studies not only as an ‚objective‘ approach to religion, but in the sense of applied/engaged religious studies? The article explores these problems also in view of possible future prospects of religious learning (not only ‘about’, but also ‘from’ in the context of ethics classes. DEUTSCH: Mit der zunehmenden Bedeutung von Ethikunterricht stellt sich auch die Frage nach der Verortung und Zugänglichmachung des Themas Religion/Weltreligionen in der schulischen Bildung. Bisher im konfessionellen Religionsunterricht angesiedelt, übernimmt meist der Ethikunterricht nun die Aufgabe einer religionswissenschaftlich gestützten Auseinandersetzung mit der Thematik. Dabei ist jedoch zu fragen, wie Religionenkunde konzeptuell im Ethikunterricht verankert werden kann ohne ein Anhängsel zum übrigen philosophisch-ethischen Unterricht zu sein. Hier bieten sich verschiedene Zugänge an. Darüber hinaus ist aber noch einmal zu fragen, ob ein Ethikunterricht im Sinne einer auch angewandten Ethik noch einmal ein umfassenderes Verständnis von Religionswissenschaft benötigt und dieses im Konzept der angewandten Religionswissenschaft finden kann. Der Artikel beleuchtet diese auch wissenschaftstheoretische Problematik im Hinblick auf mögliche Zukunftskonzepte von religiösem Lernen im Kontext des Ethikunterrichts.

  6. Die Energiesicherheit Europas in Bezug auf Erdgas und die Auswirkungen einer Kartellbildung im Gassektor

    OpenAIRE

    Krämer, Luis-Martín

    2011-01-01

    Die Dissertation untersucht die aktuelle Sicherheit der europaeischen Erdgasversorgung. Sie beruecksichtigt zudem die moeglichen Auswirkungen einer Kartellbildung auf die europaeische Gasversorgungssicherheit. Die Arbeit besteht aus einer detaillierten empirischen Studie und darauf aufbauender Szenarioanalyse. Hierzu wird auf den Interdependenzansatz von Robert O. Keohane und Joseph Nye zurueckgegriffen. Zur Darstellung des komplexen Themenbereichs wird auf die Darstellungspraxis der Dichten ...

  7. Die familiäre Bewältigung einer Krebserkrankung im Kindes- und Jugendalter - Möglichkeiten der standardisierten Erfassung mit Selbstbeurteilungsverfahren: Ergebnisse einer empirischen Vorstudie

    OpenAIRE

    Goldbeck, Lutz

    1998-01-01

    In einer schriftlichen Befragung gaben 44 Eltern pädiatrisch-onkologischer Patienten während der Therapiephase Auskunft über ihre eigene Krankheitsbewältigung sowie über die Krankheitsbewältigung und die körperlichen Beschwerden ihrer erkrankten Kinder. Die große Mehrzahl der untersuchten Familien zeigte sich aus Elternsicht den mit der Krankheit und Behandlung verbundenen Belastungen gewachsen. Aktive, problemorientierte Bewältigungssstrategien in Verbindung mit einer optimistischen Grundein...

  8. Groundwork for integration of hot water extraction as a potential pre-process in a biorefinery for downstream conversion and nano-fibrillation

    Science.gov (United States)

    Zhu, Rui

    The economic competitiveness of biofuels production is highly dependent on feedstock cost, which constitutes 35-50 % of the total biofuels production cost. Economically viable feedstock pre-process has a significant influence on all the subsequent downstream processes in the biorefinery supply chain. In this work, hot water extraction (HWE) was exploited as a pre-process to initially fractionate cell wall structure of softwood Douglas fir, which is considerably more recalcitrant compared to hardwoods and agricultural feedstocks. A response surface model was developed and the highest hemicellulose extraction yield (HEY) was obtained when the temperature is 180 °C and the time is 79 min. HWE process partially removed hemicelluloses, reduced the moisture absorption and improved the thermal stability of wood. To investigate the effects of HWE pre-process on sulfite pretreatment to overcome recalcitrance of lignocellulose (SPORL), a series of SPORL with reduced combined severity factor (CSF) were conducted using HWE treated Douglas fir. Sugar analysis after enzymatic hydrolysis indicated that SPORL can be conducted at lower temperature (145 °C), shorter time (80 min), and lower acid volume (3 %), while still maintaining considerably high enzymatic digestibility ( 55-60%). Deriving valuable co-products would increase the overall revenue and improve the economics of the biofuels supply chain. The feasibility of extracting cellulose nanofibrils (CNFs) from HWE treated Douglas fir by ultrasonication and CNFs' reinforcing potentials in nylon 6 matrix were evaluated. Morphology analysis indicated that finer fibrils can be obtained by increasing ultrasonication time and/or amplitude. CNFs was found to have higher crystallinity and maintained the thermal stability compared to untreated fiber. A method of fabricating nylon 6/CNFs as-spun nanocomposite filaments using a combination of extrusion, compounding and capillary rheometer to minimize thermal degradation of CNFs was

  9. Human Tau isoforms assemble into ribbon-like fibrils that display polymorphic structure and stability.

    Science.gov (United States)

    Wegmann, Susanne; Jung, Yu Jin; Chinnathambi, Subashchandrabose; Mandelkow, Eva-Maria; Mandelkow, Eckhard; Muller, Daniel J

    2010-08-27

    Fibrous aggregates of Tau protein are characteristic features of Alzheimer disease. We applied high resolution atomic force and EM microscopy to study fibrils assembled from different human Tau isoforms and domains. All fibrils reveal structural polymorphism; the "thin twisted" and "thin smooth" fibrils resemble flat ribbons (cross-section approximately 10 x 15 nm) with diverse twist periodicities. "Thick fibrils" show periodicities of approximately 65-70 nm and thicknesses of approximately 9-18 nm such as routinely reported for "paired helical filaments" but structurally resemble heavily twisted ribbons. Therefore, thin and thick fibrils assembled from different human Tau isoforms challenge current structural models of paired helical filaments. Furthermore, all Tau fibrils reveal axial subperiodicities of approximately 17-19 nm and, upon exposure to mechanical stress or hydrophobic surfaces, disassemble into uniform fragments that remain connected by thin thread-like structures ( approximately 2 nm). This hydrophobically induced disassembly is inhibited at enhanced electrolyte concentrations, indicating that the fragments resemble structural building blocks and the fibril integrity depends largely on hydrophobic and electrostatic interactions. Because full-length Tau and repeat domain constructs assemble into fibrils of similar thickness, the "fuzzy coat" of Tau protein termini surrounding the fibril axis is nearly invisible for atomic force microscopy and EM, presumably because of its high flexibility.

  10. The effect of point mutations on structure and mechanical properties of collagen-like fibril: A molecular dynamics study

    Energy Technology Data Exchange (ETDEWEB)

    Marlowe, Ashley E.; Singh, Abhishek; Yingling, Yaroslava G., E-mail: yara_yingling@ncsu.edu

    2012-12-01

    Understanding sequence dependent mechanical and structural properties of collagen fibrils is important for the development of artificial biomaterials for medical and nanotechnological applications. Moreover, point mutations are behind many collagen associated diseases, including Osteogenesis Imperfecta (OI). We conducted a combination of classical and steered atomistic molecular dynamics simulations to examine the effect of point mutations on structure and mechanical properties of short collagen fibrils which include mutations of glycine to alanine, aspartic acid, cysteine, and serine or mutations of hydroxyproline to arginine, asparagine, glutamine, and lysine. We found that all mutations disrupt structure and reduce strength of the collagen fibrils, which may affect the hierarchical packing of the fibrils. The glycine mutations were more detrimental to mechanical strength of the fibrils (WT > Ala > Ser > Cys > Asp) than that of hydroxyproline (WT > Arg > Gln > Asn > Lys). The clinical outcome for glycine mutations agrees well with the trend in reduction of fibril's tensile strength predicted by our simulations. Overall, our results suggest that the reduction in mechanical properties of collagen fibrils may be used to predict the clinical outcome of mutations. Highlights: Black-Right-Pointing-Pointer All mutations disrupt structure and bonding pattern and reduce strength of the collagen fibrils. Black-Right-Pointing-Pointer Gly based mutations are worst to mechanical integrity of fibrils than that of Hyp. Black-Right-Pointing-Pointer Lys and Arg mutations most dramatically destabilize collagen fibril properties. Black-Right-Pointing-Pointer Clinical outcome of mutations may be related to the reduced mechanical properties of fibrils.

  11. Atrial fibrillation in the elderly

    Institute of Scientific and Technical Information of China (English)

    Roberto A.Franken; Ronaldo F.Rosa; Silvio CM Santos

    2012-01-01

    This review discusses atrial fibrillation according to the guidelines of Brazilian Society of Cardiac Arrhythmias and the Brazilian Cardiogeriatrics Guidelines. We stress the thromboembolic burden of atrial fibrillation and discuss how to prevent it as well as the best way to conduct cases of atrial fibrillatios in the elderly, reverting the arrhythmia to sinus rhythm, or the option of heart rate control. The new methods to treat atrial fibrillation, such as radiofrequency ablation, new oral direct thrombin inhibitors and Xa factor inhibitors, as well as new antiarrhythmic drugs, are depicted.

  12. Electrostatic effects in collagen fibrillization

    Science.gov (United States)

    Morozova, Svetlana; Muthukumar, Murugappan

    2014-03-01

    Using light scattering and AFM techniques, we have measured the kinetics of fibrillization of collagen (pertinent to the vitreous of human eye) as a function of pH and ionic strength. At higher and lower pH, collagen triple-peptides remain stable in solution without fibrillization. At neutral pH, the fibrillization occurs and its growth kinetics is slowed upon either an increase in ionic strength or a decrease in temperature. We present a model, based on polymer crystallization theory, to describe the observed electrostatic nature of collagen assembly.

  13. Otobasal liquor fistula causing recurrent bacterial meningitis; Otobasale Liquorfistel als Ursache einer rezidivierenden bakteriellen Meningitis

    Energy Technology Data Exchange (ETDEWEB)

    Doege, H. [Abteilung fuer Nuklearmedizin, Leipzig Univ. (Germany); Klinghammer, A.; Elix, H. [Klinik fuer Kinder- und Jugendmedizin, Leipzig Univ. (Germany); Pilz, D. [Institut fuer Bildgebende Diagnostik der Klinikum Chemnitz gGmbH (Germany); Bootz, F. [Klinik und Poliklinik fuer Hals-Nasen-Ohren-Heilkunde/ Plastische Operationen, Leipzig Univ. (Germany)

    2000-07-01

    Cerebral subarachnoid space scintigraphy today still is the modality of choice for detection of a liquorrea or a liquor fistula, especially in the case of a recurrent menengitis of unclear origin. This diagnostic method yielded the results required in the case reported for efficient and successful surgical treatment. (orig./CB) [German] Die zerebrale Liquorraumszintigraphie ist aufgrund der hohen Empfindlichkeit auch heute noch die Methode der Wahl zum Nachweis einer Liquorrhoe beziehungsweise einer Liquorfistel, insbesondere bei einer rezidivierenden Meningitis unklarer Genese. Sie ermoeglichte bei unserer Patientin eine gezielte definitive operative Behandlung. (orig.)

  14. Hypertension and Atrial Fibrillation

    DEFF Research Database (Denmark)

    Dzeshka, Mikhail S.; Shahid, Farhan; Shantsila, Alena

    2017-01-01

    Atrial fibrillation (AF) is the most prevalent sustained arrhythmia found in clinical practice. AF rarely exists as a single entity but rather as part of a diverse clinical spectrum of cardiovascular diseases, related to structural and electrical remodeling within the left atrium, leading to AF o...... of complications as the first clinical manifestation of the disease. Antithrombotic prevention in AF combined with strict blood pressure control is of primary importance, since stroke risk and bleeding risk are both greater with underlying hypertension....... onset, perpetuation, and progression. Due to the high overall prevalence within the AF population arterial hypertension plays a significant role in the pathogenesis of AF and its complications. Fibroblast proliferation, apoptosis of cardiomyocytes, gap junction remodeling, accumulation of collagen both...... in atrial and ventricular myocardium all accompany ageing-related structural remodeling with impact on electrical activity. The presence of hypertension also stimulates oxidative stress, systemic inflammation, rennin-angiotensin-aldosterone and sympathetic activation, which further drives the remodeling...

  15. Cost-effectiveness of a specialized atrial fibrillation clinic vs. usual care in patients with atrial fibrillation

    NARCIS (Netherlands)

    Hendriks, Jeroen; Tomini, Florian; van Asselt, Thea; Crijns, Harry; Vrijhoef, Hubertus

    2013-01-01

    AIMS: A recent randomized controlled trial demonstrated significant reductions in cardiovascular hospitalizations and deaths with a nurse-led integrated chronic care approach in patients with atrial fibrillation (AF) compared with usual care. The aim of the present study is to assess cost-effectiven

  16. Design of a modular cogeneration plant to supply residential buildings; Dimensionierung eines Blockheizkraftwerkes zur Versorgung einer Wohnsiedlung

    Energy Technology Data Exchange (ETDEWEB)

    Marquardt, R.

    2000-03-01

    Excel tables are presented for fast integral calculation of all energetic and monetary parameters required for calculating the economic efficiency of a cogeneration plant. The Excel programming is more detailed than the method of calculation specified in VDI 2067 in that it also provides potential energy savings,carbon dioxide reduction and exergetic calculations. Influencing parameters like technical data, energy consumption data, fuel properties, and the cost structure of electricity and heat supply can be freely chosen so as to enable maximum parameter variation and an analysis of their influence on the result. [German] Mit der vorliegenden Arbeit wurde ein Instrument in Form von Excel-Tabellen erstellt, das eine schnelle integrale Berechnung aller energetischen und monetaeren Ergebnisgroessen ermoeglicht, die beim Einsatz eines BHKW zur Versorgung einer Bedarfsstruktur im Vergleich zu einer konventionellen getrennten Energiebereitstellung von Interesse sind. Die Excel-Programmierung geht dabei ueber die Abbildung des in der VDI 2067 beschriebenen Berechnungsverfahrens hinaus und liefert neben der Berechnung der Waermebereitstellungskosten auch die Ermittlung von Energieeinspar-, CO{sub 2}-Minderungspotentialen sowie eine exergetische Betrachtung der Ergebnisse. Alle auf das Ergebnis einwirkende Parameter wie technische Anlagendaten, Energiebedarfswerte, Brennstoffeigenschaften, Kostenstruktur der Elektrizitaets- und Waermeversorgung u.a. sind prinzipiell frei waehlbar. So wurde sichergestellt, dass eine Variation verschiedener Parameter moeglich ist und deren Einfluss auf das Ergebnis analysiert werden kann. (orig.)

  17. Mechanical properties of collagen fibrils

    OpenAIRE

    Wenger, M. P. E.; Bozec, L.; Horton, M. A.; Mesquida, P

    2007-01-01

    The formation of collagen fibers from staggered subfibrils still lacks a universally accepted model. Determining the mechanical properties of single collagen fibrils ( diameter 50 - 200 nm) provides new insights into collagen structure. In this work, the reduced modulus of collagen was measured by nanoindentation using atomic force microscopy. For individual type 1 collagen fibrils from rat tail, the modulus was found to be in the range from 5 GPa to 11.5 GPa ( in air and at room temperature)...

  18. Zur Notwendigkeit der Bestimmung einer auf Digitale Medien fokussierten Medienkompetenz und Medienbildung

    Directory of Open Access Journals (Sweden)

    Isabel Zorn

    2011-09-01

    Full Text Available Die neuartigen Herausforderungen an Bildung aufgrund der Digitalen Medien erfordern einen theoretischen Rahmen, der Prinzipien und Spezifika der Digitalen Medien berücksichtigt. Darauf zielt dieser Beitrag. Er wird dazu zunächst skizzieren, worin die Spezifika Digitaler Medien liegen, um danach zu analysieren ob, wie und in welchen Kontexten diese von der Medienpädagogik aufgegriffen werden. Dazu werden verschiedene Perspektiven der Medienpädagogik einer Analyse unterzogen: Perspektiven auf Medienkompetenz, Medienbildung und Medienliteralität. Aufbauend auf dem zu ziehenden Fazit, dass die technologischen Grundlagen und spezifischen Herausforderungen der Digitalen Medien bislang in Bildungskonzepten wenig berücksichtigt sind, werden im zweiten Abschnitt die Bildungsrelevanzen und -potenziale einer solchen Perspektive herausgearbeitet, um als Konsequenz auf die Bedeutungen von «Digitaler Medienkompetenz» und die Notwendigkeit einer Konzeption einer speziell auf Digitale Medien ausgerichteten «Digitalen Medienbildung» zu argumentieren.

  19. Selektive Aufmerksamkeitslenkung bei einer Risikogruppe für Idiopathic Environmental Intolerance

    OpenAIRE

    Nischk, D. (Daniel)

    2003-01-01

    Idiopathic Environmental Intolerance (IEI; vormals multiple chemische Sensitivität) bezeichnet ein polysymptomatisches Beschwerdebild, das von den Betroffenen auf die niederschwellige Exposition mit chemischen Substanzen attribuiert wird. Die Hypothese einer selektiven Aufmerksamkeitslenkung von IEI-Betroffenen auf chemische Auslösereize sowie auf damit assoziierte körperliche Beschwerden wurde anhand einer IEI-Risikogruppe von 20 Geruchssensitiven und 21 Kontrollpersonen in einem modifizier...

  20. Amyloid plaque structure and cell surface interactions of β-amyloid fibrils revealed by electron tomography

    Science.gov (United States)

    Han, Shen; Kollmer, Marius; Markx, Daniel; Claus, Stephanie; Walther, Paul; Fändrich, Marcus

    2017-01-01

    The deposition of amyloid fibrils as plaques is a key feature of several neurodegenerative diseases including in particular Alzheimer’s. This disease is characterized, if not provoked, by amyloid aggregates formed from Aβ peptide that deposit inside the brain or are toxic to neuronal cells. We here used scanning transmission electron microscopy (STEM) to determine the fibril network structure and interactions of Aβ fibrils within a cell culture model of Alzheimer’s disease. STEM images taken from the formed Aβ amyloid deposits revealed three main types of fibril network structures, termed amorphous meshwork, fibril bundle and amyloid star. All three were infiltrated by different types of lipid inclusions from small-sized exosome-like structures (50–100 nm diameter) to large-sized extracellular vesicles (up to 300 nm). The fibrils also presented strong interactions with the surrounding cells such that fibril bundles extended into tubular invaginations of the plasma membrane. Amyloid formation in the cell model was previously found to have an intracellular origin and we show here that it functionally destroys the integrity of the intracellular membranes as it leads to lysosomal leakage. These data provide a mechanistic link to explain why intracellular fibril formation is toxic to the cell. PMID:28240273

  1. Human Tau Isoforms Assemble into Ribbon-like Fibrils That Display Polymorphic Structure and Stability*

    Science.gov (United States)

    Wegmann, Susanne; Jung, Yu Jin; Chinnathambi, Subashchandrabose; Mandelkow, Eva-Maria; Mandelkow, Eckhard; Muller, Daniel J.

    2010-01-01

    Fibrous aggregates of Tau protein are characteristic features of Alzheimer disease. We applied high resolution atomic force and EM microscopy to study fibrils assembled from different human Tau isoforms and domains. All fibrils reveal structural polymorphism; the “thin twisted” and “thin smooth” fibrils resemble flat ribbons (cross-section ∼10 × 15 nm) with diverse twist periodicities. “Thick fibrils” show periodicities of ∼65–70 nm and thicknesses of ∼9–18 nm such as routinely reported for “paired helical filaments” but structurally resemble heavily twisted ribbons. Therefore, thin and thick fibrils assembled from different human Tau isoforms challenge current structural models of paired helical filaments. Furthermore, all Tau fibrils reveal axial subperiodicities of ∼17–19 nm and, upon exposure to mechanical stress or hydrophobic surfaces, disassemble into uniform fragments that remain connected by thin thread-like structures (∼2 nm). This hydrophobically induced disassembly is inhibited at enhanced electrolyte concentrations, indicating that the fragments resemble structural building blocks and the fibril integrity depends largely on hydrophobic and electrostatic interactions. Because full-length Tau and repeat domain constructs assemble into fibrils of similar thickness, the “fuzzy coat” of Tau protein termini surrounding the fibril axis is nearly invisible for atomic force microscopy and EM, presumably because of its high flexibility. PMID:20566652

  2. Numerical optimisation of an axial turbine; Numerische Optimierung einer Axialturbine

    Energy Technology Data Exchange (ETDEWEB)

    Welzel, B.

    1998-12-31

    The author presents a method for automatic shape optimisation of components with internal or external flow. The method combines a program for numerical calculation of frictional turbulent flow with an optimisation algorithm. Algorithms are a simplex search strategy and an evolution strategy. The shape of the component to be optimized is variable due to shape parameters modified by the algorithm. For each shape, a flow calculation is carried out on whose basis a functional value like performance, loss, lift or resistivity is calculated. For validation, the optimisation method is used in simple examples with known solutions. It is applied. It is applied to the components of a slow-running axial turbine. Components with accelerated and delayed rotationally symmetric flow and 2D blade profiles are optimized. [Deutsch] Es wird eine Methode zur automatischen Formoptimierung durchstroemter oder umstroemter Bauteile vorgestellt. Diese koppelt ein Programm zur numerischen Berechnung reibungsbehafteter turbulenter Stroemungen mit einem Optimierungsalgorithmus. Dabei kommen als Algorithmen eine Simplex-Suchstrategie und eine Evolutionsstrategie zum Einsatz. Die Form des zu optimierenden Koerpers ist durch Formparameter, die vom Algorithmus veraendert werden, variabel. Fuer jede Form wird eine Stroemungsberechnung durchgefuehrt und mit dieser ein Funktionswert wie Wirkungsgrad, Verlust, Auftrieb oder Widerstandskraft berechnet. Die Optimierungsmethode wird zur Validierung in einfachen Beispielen mit bekannter Loesung eingesetzt. Zur Anwendung kommt sie in den einzelnen Komponenten einer langsamlaeufigen Axialturbine. Es werden Bauteile mit beschleunigter und verzoegerter rotationssymmetrischer Stroemung und 2D-Schaufelprofile optimiert. (orig.)

  3. Casual sequences preceding coal dust explosions; Ursachenkette einer Kohlenstaubexplosion

    Energy Technology Data Exchange (ETDEWEB)

    Cichowski, E. [Schlesische Technische Univ., Gleiwitz (Poland); Faber, M. [Bergbau-Versuchsstrecke, DMT Gas and Fire Division, Bochum (Germany)

    2002-12-01

    The paper examines the causal sequence which precedes a possible coaldust explosion in the Polish coal industry. Each occurrence is prefaced by a sequence of necessary causes. Here it is assumed that the component parts of the required causal sequence are always present when the undesired final occurrence takes place. An identification of the causality of the coal-dust explosion often complicates this process, such that both the initiation and the consequences of the explosion can be linked to various changes in the parameters associated with the working environment. The essential aspect of the accident hazard and of the ensuing risk to the winning operation results from the causality factor, which is dependent on various safety deficiencies. The safety deficiencies presented can be due to parameters associated with the working environment or to human actions. (orig.) [German] Im vorliegenden Beitrag wird die Ursachenkette betrachtet, die einer moeglichen Kohlenstaubexplosion im polnischen Steinkohlenbergbau vorausgeht. Jeder Folge geht eine Kette notwendiger Ursachen voraus. Dabei wird angenommen, dass Bestandteile der notwendigen Ursachenkette immer auftreten, wenn die unerwuenschte Endfolge geschieht. Die Identifizierung der Kausalitaet der Kohlenstaubexplosion kompliziert oft diesen Vorgang, so dass sowohl das Initiieren als auch die Folgen der Kohlenstaubexplosion mit verschiedenen Aenderungen der Arbeitsumweltparameter verknuepft sein koennen. Das Wesentliche der Unfallgefaehrdung und des auftretenden Risikos der Gewinnung resultiert aus der Kausalitaet, die unterschiedliche Sicherheitsdefizite bedingen. Die angefuehrten Sicherheitsdefizite koennen seitens der Arbeitsumweltparameter sowie seitens menschlicher Einfluesse auftreten. (orig.)

  4. Atrial fibrillation and heart failure: is atrial fibrillation a disease?

    Science.gov (United States)

    Tilman, V

    2014-09-01

    Atrial fibrillation in heart failure often occur together. The relationship between atrial fibrillation and heart failure has remained a subject of research. The main manifestation of the violation of hydrodynamics in heart failure is the increased end-diastolic pressure, which is transmitted through the intercommunicated system (left ventricle-left atrium-pulmonary veins-alveolar capillaries) causing increased pulmonary wedge pressure with the danger for pulmonary edema. End-diastolic pressure is the sum of left ventricle diastolic pressure and left atrial systolic pressure. Stopping the mechanical systole of the left atrium can reduce the pressure in the system in heart failure. Atrial fibrillation stops the mechanical systole of the left atrium and decreases the intercommunicating pressure and pulmonary wedge pressure. It is possible that atrial fibrillation is a mechanism for protection from increasing end-diastolic pressure and pulmonary wedge pressure, and prevents the danger of pulmonary edema. This hypothesis may explain the relationship between heart failure and atrial fibrillation and their frequent association.

  5. Pack also the sauna. Integration of electricity storage; Auch die Sauna mit rein. Einbindung von Stromspeichern

    Energy Technology Data Exchange (ETDEWEB)

    Ullrich, Sven

    2013-10-01

    The installers have to handle with a variety of variables and options to plan and integrate the correct personal use system of solar power systems for their customers. [German] Die Installateure muessen mit einer Vielzahl von Variablen und Varianten zurechtkommen, um das richtige Eigenverbrauchssystem einer Solarstromanlage fuer ihre Kunden zu planen und einzubauen.

  6. Molecular recycling within amyloid fibrils.

    Science.gov (United States)

    Carulla, Natàlia; Caddy, Gemma L; Hall, Damien R; Zurdo, Jesús; Gairí, Margarida; Feliz, Miguel; Giralt, Ernest; Robinson, Carol V; Dobson, Christopher M

    2005-07-28

    Amyloid fibrils are thread-like protein aggregates with a core region formed from repetitive arrays of beta-sheets oriented parallel to the fibril axis. Such structures were first recognized in clinical disorders, but more recently have also been linked to a variety of non-pathogenic phenomena ranging from the transfer of genetic information to synaptic changes associated with memory. The observation that many proteins can convert into similar structures in vitro has suggested that this ability is a generic feature of polypeptide chains. Here we have probed the nature of the amyloid structure by monitoring hydrogen/deuterium exchange in fibrils formed from an SH3 domain using a combination of nuclear magnetic resonance spectroscopy and electrospray ionization mass spectrometry. The results reveal that under the conditions used in this study, exchange is dominated by a mechanism of dissociation and re-association that results in the recycling of molecules within the fibril population. This insight into the dynamic nature of amyloid fibrils, and the ability to determine the parameters that define this behaviour, have important implications for the design of therapeutic strategies directed against amyloid disease.

  7. Imaging and 3D morphological analysis of collagen fibrils.

    Science.gov (United States)

    Altendorf, H; Decencière, E; Jeulin, D; De sa Peixoto, P; Deniset-Besseau, A; Angelini, E; Mosser, G; Schanne-Klein, M-C

    2012-08-01

    The recent booming of multiphoton imaging of collagen fibrils by means of second harmonic generation microscopy generates the need for the development and automation of quantitative methods for image analysis. Standard approaches sequentially analyse two-dimensional (2D) slices to gain knowledge on the spatial arrangement and dimension of the fibrils, whereas the reconstructed three-dimensional (3D) image yields better information about these characteristics. In this work, a 3D analysis method is proposed for second harmonic generation images of collagen fibrils, based on a recently developed 3D fibre quantification method. This analysis uses operators from mathematical morphology. The fibril structure is scanned with a directional distance transform. Inertia moments of the directional distances yield the main fibre orientation, corresponding to the main inertia axis. The collaboration of directional distances and fibre orientation delivers a geometrical estimate of the fibre radius. The results include local maps as well as global distribution of orientation and radius of the fibrils over the 3D image. They also bring a segmentation of the image into foreground and background, as well as a classification of the foreground pixels into the preferred orientations. This accurate determination of the spatial arrangement of the fibrils within a 3D data set will be most relevant in biomedical applications. It brings the possibility to monitor remodelling of collagen tissues upon a variety of injuries and to guide tissues engineering because biomimetic 3D organizations and density are requested for better integration of implants. © 2012 The Authors Journal of Microscopy © 2012 Royal Microscopical Society.

  8. Mapping out the multistage fibrillation of glucagon

    DEFF Research Database (Denmark)

    Ghodke, Shirin; Nielsen, Søren B.; Christiansen, Gunna

    2012-01-01

    unusual far‐UV CD spectra to tertiary‐level structural changes during the formation and maturation of fibrils. The fibrillation model for the whole process involves the formation of three oligomeric species and two different morphologies of fibrils in the same solution. The visualization of annular pore...... fibrillar state and identifies the importance of fibril twisting for its thermodynamic stabilization. Structured digital abstract and by () and by () and by ()...

  9. Atrial fibrillation and delayed gastric emptying.

    Directory of Open Access Journals (Sweden)

    Isadora C Botwinick

    Full Text Available BACKGROUND: Atrial fibrillation and delayed gastric emptying (DGE are common after pancreaticoduodenectomy. Our aim was to investigate a potential relationship between atrial fibrillation and DGE, which we defined as failure to tolerate a regular diet by the 7(th postoperative day. METHODS: We performed a retrospective chart review of 249 patients who underwent pancreaticoduodenectomy at our institution between 2000 and 2009. Data was analyzed with Fisher exact test for categorical variables and Mann-Whitney U or unpaired T-test for continuous variables. RESULTS: Approximately 5% of the 249 patients included in the analysis experienced at least one episode of postoperative atrial fibrillation. Median age of patients with atrial fibrillation was 74 years, compared with 66 years in patients without atrial fibrillation (p = 0.0005. Patients with atrial fibrillation were more likely to have a history of atrial fibrillation (p = 0.03. 92% of the patients with atrial fibrillation suffered from DGE, compared to 46% of patients without atrial fibrillation (p = 0.0007. This association held true when controlling for age. CONCLUSION: Patients with postoperative atrial fibrillation are more likely to experience delayed gastric emptying. Interventions to manage delayed gastric function might be prudent in patients at high risk for postoperative atrial fibrillation.

  10. Dynamics of Fibril Growth and Feedback Motifs

    DEFF Research Database (Denmark)

    Cordsen, Pia

    in the literature were found, such as length distribution and apparant persistence lengths. It is found that at all concentrations, fibril growth is characterized by Poissonian stop-go dynamics where the fibril either grows (``go'') or does not grow (``stop''). A monomer-trimer model is proposed in which monomers...... and trimers exist in equilibrium with monomers dominating at low concentrations and trimers dominating at high concentrations. In the model, fibrils consist either of monomers or of trimers and fibril growth is inhibited when the other species binds reversibly to the fibril. Growth probability is derived from...... chemical reaction rates of the model, and the theoretical and experimental growth probabilities are found to be in good agreement. Speed distributions of fibrils are also analysed and found to be in good agreement with the predictions of the model. Fibrils of the protein alpha-synuclein which are involved...

  11. [New antithrombotics for atrial fibrillation].

    NARCIS (Netherlands)

    Verheugt, F.W.A.

    2011-01-01

    Cerebral infarction is the most serious complication of atrial fibrillation. Coumarin derivatives (vitamin K antagonists) counteract systemic thromboembolism and reduce the risk of stroke by more than 60%, but carry a risk of serious bleeding. Antiplatelet therapy and subcutaneous low-molecular-weig

  12. Radiofrequency ablation of atrial fibrillation

    NARCIS (Netherlands)

    Wiesfeld, ACP; Tan, ES; Van Veldhuisen, DJ; Crijns, HJGM; Van Gelder, IC

    2004-01-01

    Twenty-five patients (16 males, mean age 46 years.) underwent radiofrequency ablation because of either paroxysmal (13 patients) or persistent atrial fibrillation (12 patients). Ablation aimed at earliest activation of spontaneous and catheter-induced repetitive ectopy in left and right atria and ap

  13. Genetic basis of atrial fibrillation

    Directory of Open Access Journals (Sweden)

    Oscar Campuzano

    2016-12-01

    Full Text Available Atrial fibrillation is the most common sustained arrhythmia and remains as one of main challenges in current clinical practice. The disease may be induced secondary to other diseases such as hypertension, valvular heart disease, and heart failure, conferring an increased risk of stroke and sudden death. Epidemiological studies have provided evidence that genetic factors play an important role and up to 30% of clinically diagnosed patients may have a family history of atrial fibrillation. To date, several rare variants have been identified in a wide range of genes associated with ionic channels, calcium handling protein, fibrosis, conduction and inflammation. Important advances in clinical, genetic and molecular basis have been performed over the last decade, improving diagnosis and treatment. However, the genetics of atrial fibrillation is complex and pathophysiological data remains still unraveling. A better understanding of the genetic basis will induce accurate risk stratification and personalized clinical treatment. In this review, we have focused on current genetics basis of atrial fibrillation.

  14. Nonlinear Dynamical Analysis of Fibrillation

    Science.gov (United States)

    Kerin, John A.; Sporrer, Justin M.; Egolf, David A.

    2013-03-01

    The development of spatiotemporal chaotic behavior in heart tissue, termed fibrillation, is a devastating, life-threatening condition. The chaotic behavior of electrochemical signals, in the form of spiral waves, causes the muscles of the heart to contract in an incoherent manner, hindering the heart's ability to pump blood. We have applied the mathematical tools of nonlinear dynamics to large-scale simulations of a model of fibrillating heart tissue to uncover the dynamical modes driving this chaos. By studying the evolution of Lyapunov vectors and exponents over short times, we have found that the fibrillating tissue is sensitive to electrical perturbations only in narrow regions immediately in front of the leading edges of spiral waves, especially when these waves collide, break apart, or hit the edges of the tissue sample. Using this knowledge, we have applied small stimuli to areas of varying sensitivity. By studying the evolution of the effects of these perturbations, we have made progress toward controlling the electrochemical patterns associated with heart fibrillation. This work was supported by the U.S. National Science Foundation (DMR-0094178) and Research Corporation.

  15. Fracture mechanics of collagen fibrils

    DEFF Research Database (Denmark)

    Svensson, Rene B; Mulder, Hindrik; Kovanen, Vuokko

    2013-01-01

    Tendons are important load-bearing structures, which are frequently injured in both sports and work. Type I collagen fibrils are the primary components of tendons and carry most of the mechanical loads experienced by the tissue, however, knowledge of how load is transmitted between and within...

  16. Personalized management of atrial fibrillation

    DEFF Research Database (Denmark)

    Kirchhof, Paulus; Breithardt, Günter; Aliot, Etienne

    2013-01-01

    The management of atrial fibrillation (AF) has seen marked changes in past years, with the introduction of new oral anticoagulants, new antiarrhythmic drugs, and the emergence of catheter ablation as a common intervention for rhythm control. Furthermore, new technologies enhance our ability to de...

  17. [Atrial fibrillation and cognitive function].

    Science.gov (United States)

    Duron, Emmanuelle; Hanon, Olivier

    2010-09-01

    Atrial fibrillation (AF), which prevalence increases with age, is a growing public health problem and a well known risk factor for stroke. On the other hand, dementia is one of the most important neurological disorders in the elderly, and with aging of the population in developed countries, the number of demented patients will increase in absence of prevention. In the past decade, several vascular risk factors (hypertension, obesity and metabolic syndrome, hypercholesterolemia) have been found, with various degree of evidence, to be associated with vascular dementia but also, surprisingly, with Alzheimer's disease. This review is devoted to the links between atrial fibrillation, cognitive decline and dementia. Globally, transversal studies showed a significant association between atrial fibrillation, cognitive decline and dementia. However, these studies are particularly sensitive to various biases. In this context, recent longitudinal studies of higher level of evidence have been conducted to assess the link between AF and dementia. One study disclosed a high incidence of dementia among patients suffering from atrial fibrillation during a 4.6 years follow-up. Similarly another study showed that atrial fibrillation was significantly associated with conversion from mild cognitive impairment to dementia during a 3 years follow-up. Nevertheless two other longitudinal studies did not find any significant association between AF and dementia, but this discrepancy should be interpreted taking into account that the comparability of all these studies is moderate because they were using different methodologies (population, cognitive testing, and mean follow-up). Possible explanatory mechanisms for the association between AF and the risk of dementia are proposed, such as thrombo-embolic ischemic damage and cerebral hypo perfusion due to fluctuations in the cardiac output. Thus, there is some evidence that FA could be associated with cognitive decline and dementia but this

  18. LCF/HCF-Wechselwirkungen in einer Nickelbasis-Gusslegierung bei erhöhter Temperatur

    OpenAIRE

    Gelmedin, Domnin

    2013-01-01

    Das Ermüdungsverhalten von MAR-M247 LC wurde bei 650 °C unter LCF-, HCF- und kombinierter LCF/HCF-Beanspruchung untersucht. Die überlagerte HCF-Beanspruchung führt zu einer Reduktion der Ermüdungslebensdauer aufgrund einer Beschleunigung der LCF dominierten Rissbildung und Rissausbreitung sowie dem Übergang zum eigenständigen HCF-Risswachstum. Ein Schädigungsfaktor bewertet die überlagerte HCF-Beanspruchung, indem eine negative und positive Wirkung berücksichtigt wird.

  19. Multiple Sklerose und Psychopathologie - retrospektive Untersuchung über psychiatrisch-psychosomatische Befunde bei PatientInnen einer neurologischen Rehabilitationseinrichtung

    OpenAIRE

    2008-01-01

    Die retrospektive Untersuchung behandelt das Phänomen der psychischen Komorbidität bei Multiple Sklerose (MS), einer der häufigsten neurologischen Erkrankungen. Es wird anhand von Datenmaterial aus einer neurologischen Rehabilitationseinrichtung untersucht, inwiefern sich MS-PatientInnen mit und ohne dokumentierte psychische Komorbidität hinsichtlich verschiedener Parameter unterscheiden. Insgesamt zeigen sich deutliche Unterschie...

  20. Dosis- Wirkungsbeziehung einer Interferon beta Therapie auf die endogene Interferon beta Produktion am Beispiel einer Therapie mit Interferon beta 1a 22 myg versus 22 myg/44 myg

    OpenAIRE

    2011-01-01

    Die Multiple Sklerose ist die häufigste chronisch- entzündliche ZNS- Erkrankung in der westlichen Welt und Australien. Die Pathophysiologie beruht auf autoreaktiven T- Zellen, welche sich vornehmlich gegen das myelobasische Protein von Oligodendrozyten richten. Nachfolgend kommt zu einer Zerstörung der Myelinscheiden, Axonalschaden und sekundärer Sklerosierung. In der Behandlung der schubförmigen multiplen Sklerose (relapsing remitting (RR)) werden, gemäß der Therapieleitlinien der Multipl...

  1. Zeitabhängige Putzeffektivität einer neuen Handzahnbürste im Vergleich mit einer ADA-Referenzzahnbürste

    OpenAIRE

    Nagler, Tonia

    2011-01-01

    Ziel:Ziel dieser Studie war es, in einer professionellen Zahnputzstudie die Reinigungseffektivität zweier unterschiedlicher Handzahnbürsten (Elmex Sensitive, ADA-Handzahnbürste) in Abhängigkeit von der Putzzeit miteinander zu vergleichen. Material und Methode:An dieser einfach verblindeten, randomisierten Studie nahmen insgesamt 90 nicht zahnmedizinisch vorgebildete Probanden im Alter zwischen 18 und 35 Jahren teil. Die Studie folgte einem Cross-over-Design und bestand insgesamt aus drei vers...

  2. Investigations regarding the mass budget in the propagation of a passive admixture from a line source; Untersuchungen zur Stoffbilanz bei der Ausbreitung einer passiven Beimengung aus einer Linienquelle

    Energy Technology Data Exchange (ETDEWEB)

    Wenzel, A. [Brandenburgische Technische Univ. Cottbus (Germany). Inst. fuer Boden-, Luft- und Gewaesserschutz

    1998-01-01

    Under stationary conditions, passive admixtures are transported by advection and by vertical as well as horizontal turbulent diffusion. The importance of individual contributions for the exchange of passive admixtures emanating from a straight line source with a constant source strength under neutral stratification conditions is discussed. For this purpose, all terms of the mass budget for a control volume around a straight line source are calculated using a stochastic Lagrange model (LS), whose properties are discussed. As a test for the LS model, the vertical and horizontal mass flows in the soil layer are simulated and compared with SANA data. The mass flows calculated for the propagation of a passive admixture from a line source are evaluated regarding their share of the mass budget. (orig.) [Deutsch] Unter stationaeren Bedingungen erfolgt der Transport von passiven Beimengungen durch Advektion sowie vertikale und horizontale turbulente Diffusion. Die Bedeutung der einzelnen Beitraege fuer den Austausch von passiven Beimengungen, die von einer geraden Linienquelle mit konstanter Quellstaerke unter neutralen Schichtungsbedingungen ausgehen, wird diskutiert. Dazu werden mit einem Lagrangeschen stochastischen (LS) Modell, dessen Eigenschaften besprochen werden, alle Terme der Stoffbilanz fuer ein Kontrollvolumen um eine gerade Linienquelle berechnet. Als Test fuer das LS-Modell werden die vertikalen und die horizontalen Stofffluesse in der Bodenschicht simuliert und mit SANA-Daten verglichen. Die fuer die Ausbreitung einer passiven Beimengung von einer Linienquelle berechneten Massenfluesse, werden hinsichtlich ihres Anteils an der Stoffbilanz ausgewertet. (orig.)

  3. Biphasic function of focal adhesion kinase in endothelial tube formation induced by fibril-forming collagens.

    Science.gov (United States)

    Nakamura, Junko; Shigematsu, Satoshi; Yamauchi, Keishi; Takeda, Teiji; Yamazaki, Masanori; Kakizawa, Tomoko; Hashizume, Kiyoshi

    2008-10-03

    Migration and tube formation of endothelial cells are important in angiogenesis and require a coordinated response to the extra-cellular matrix (ECM) and growth factor. Since focal adhesion kinase (FAK) integrates signals from both ECM and growth factor, we investigated its role in angiogenesis. Type I and II collagens are fibril-forming collagens and stimulate human umbilical vein endothelial cells (HUVECs) to form tube structure. Although knockdown of FAK restrained cell motility and resulted in inhibition of tube formation, FAK degradation and tube formation occurred simultaneously after incubation with fibril-forming collagens. The compensation for the FAK degradation by a calpain inhibitor or transient over-expression of FAK resulted in disturbance of tube formation. These phenomena are specific to fibril-forming collagens and mediated via alpha2beta1 integrin. In conclusion, our data indicate that FAK is functioning in cell migration, but fibril-forming collagen-induced FAK degradation is necessary for endothelial tube formation.

  4. Risk of atrial fibrillation in diabetes mellitus

    DEFF Research Database (Denmark)

    Pallisgaard, Jannik L.; Schjerning, Anne-Marie; Lindhardt, Tommi B.

    2016-01-01

    AIM: Diabetes has been associated with atrial fibrillation but the current evidence is conflicting. In particular knowledge regarding young diabetes patients and the risk of developing atrial fibrillation is sparse. The aim of our study was to investigate the risk of atrial fibrillation in patients...... with diabetes compared to the background population in Denmark. METHODS AND RESULTS: Through Danish nationwide registries we included persons above 18 years of age and without prior atrial fibrillation and/or diabetes from 1996 to 2012. The study cohort was divided into a background population without diabetes...... and a diabetes group. The absolute risk of developing atrial fibrillation was calculated and Poisson regression models adjusted for sex, age and comorbidities were used to calculate incidence rate ratios of atrial fibrillation. The total study cohort included 5,081,087 persons, 4,827,713 (95%) in the background...

  5. Shared decision-making : Entscheidungserleben von Patienten im Verlauf einer Krebserkrankung

    OpenAIRE

    Thielhorn, Ulrike

    2008-01-01

    Chronische Krankheiten - wie beispielsweise Krebserkrankungen - bestimmen zunehmend das Krankheitsgeschehen in den industrialisierten Ländern. Mit ihnen wächst die Dringlichkeit zu einer konsequenten Patienten- beziehungsweise Nutzerorientierung bei der Interaktiongestaltung zwischen Patienten und Behandelnden. Dies steht im Einklang mit Demokratisierungstendenzen im Gesundheitswesen, im Zuge derer das Modell des benevolenten Paternalismus, welches durch ein hohes Maß an Asymmetrie in der Bez...

  6. Entwicklung einer Norm zur indirekten Bestimmung der Rad-Schiene-Rauheit aus der Messung von Schienenschwindungen

    NARCIS (Netherlands)

    Dittrich, M.G.; Engels, R.; Dupuis, H.; Meunier, N.

    2012-01-01

    Der Normungsausschuss CEN TC256/WG3 Subgroup E befasst sich zurzeit mit dem Thema der indirekten Bestimmung der Rad-Schiene-Rauheit aus Schienenschwingungen. In diesem Zusammenhang wurden zur Vorbereitung einer Norm verschiedene Analyseverfahren in Hin-blick auf deren Repräsentativität, Wiederholbar

  7. Atrial fibrillation in the elderly

    Institute of Scientific and Technical Information of China (English)

    Roger Kerzner; Michael W. Rich

    2005-01-01

    Atrial fibrillation (AF) is an extremely common condition in the elderly, with increasing prevalence around the world as the population ages. AF may be associated with serious health consequences, including stroke, heart failure, and decreased quality of life, so that careful management of AF by geriatric health care providers is required. With careful attention to anticoagulation therapy, and prudent use of medications and invasive procedures to minimize symptoms, many of the adverse health consequences of AF can be prevented.

  8. Method of an integrated and advanced evaluation of vulnerability. Conceptional-methodical fundamentals and examplary implementation for the water household, power generation and energetic utilisation of wood under climatic change; Methode einer integrierten und erweiterten Vulnerabilitaetsbewertung. Konzeptionell-methodische Grundlagen und exemplarische Umsetzung fuer Wasserhaushalt, Stromerzeugung und energetische Nutzung von Holz unter Klimawandel

    Energy Technology Data Exchange (ETDEWEB)

    Weisz, Helga; Koch, Hagen; Lasch, Petra [Potsdam-Institut fuer Klimafolgenforschung e.V. (Germany)] [and others

    2013-07-15

    Actually, in Germany there are more than hundred investigations on the consequences of the climatic change. It is difficult to evaluate the vulnerability of Germany against the climatic change. Under this aspect, the authors of the contributions report on a method of an integrated and advanced evaluation of vulnerability: Conceptional-methodical fundamentals and exemplary implementation for water household, power generation and energetic utilization of wood under climatic change.

  9. Alginate-Collagen Fibril Composite Hydrogel.

    Science.gov (United States)

    Baniasadi, Mahmoud; Minary-Jolandan, Majid

    2015-02-16

    We report on the synthesis and the mechanical characterization of an alginate-collagen fibril composite hydrogel. Native type I collagen fibrils were used to synthesize the fibrous composite hydrogel. We characterized the mechanical properties of the fabricated fibrous hydrogel using tensile testing; rheometry and atomic force microscope (AFM)-based nanoindentation experiments. The results show that addition of type I collagen fibrils improves the rheological and indentation properties of the hydrogel.

  10. Alginate-Collagen Fibril Composite Hydrogel

    Directory of Open Access Journals (Sweden)

    Mahmoud Baniasadi

    2015-02-01

    Full Text Available We report on the synthesis and the mechanical characterization of an alginate-collagen fibril composite hydrogel. Native type I collagen fibrils were used to synthesize the fibrous composite hydrogel. We characterized the mechanical properties of the fabricated fibrous hydrogel using tensile testing; rheometry and atomic force microscope (AFM-based nanoindentation experiments. The results show that addition of type I collagen fibrils improves the rheological and indentation properties of the hydrogel.

  11. Quenched Hydrogen Exchange NMR of Amyloid Fibrils.

    Science.gov (United States)

    Alexandrescu, Andrei T

    2016-01-01

    Amyloid fibrils are associated with a number of human diseases. These aggregatively misfolded intermolecular β-sheet assemblies constitute some of the most challenging targets in structural biology because to their complexity, size, and insolubility. Here, protocols and controls are described for experiments designed to study hydrogen-bonding in amyloid fibrils indirectly, by transferring information about amide proton occupancy in the fibrils to the dimethyl sulfoxide-denatured state. Since the denatured state is amenable to solution NMR spectroscopy, the method can provide residue-level-resolution data on hydrogen exchange for the monomers that make up the fibrils.

  12. The role of protonation in protein fibrillation

    DEFF Research Database (Denmark)

    Jeppesen, Martin D; Westh, Peter; Otzen, Daniel E

    2010-01-01

    Many proteins fibrillate at low pH despite a high population of charged side chains. Therefore exchange of protons between the fibrillating peptide and its surroundings may play an important role in fibrillation. Here, we use isothermal titration calorimetry to measure exchange of protons between...... buffer and the peptide hormone glucagon during fibrillation. Glucagon absorbs or releases protons to an extent which allows it to attain a net charge of zero in the fibrillar state, both at acidic and basic pH. Similar results are obtained for lysozyme. This suggests that side chain pKa values change...

  13. Collagen fibril diameter and leather strength.

    Science.gov (United States)

    Wells, Hannah C; Edmonds, Richard L; Kirby, Nigel; Hawley, Adrian; Mudie, Stephen T; Haverkamp, Richard G

    2013-11-27

    The main structural component of leather and skin is type I collagen in the form of strong fibrils. Strength is an important property of leather, and the way in which collagen contributes to the strength is not fully understood. Synchrotron-based small angle X-ray scattering (SAXS) is used to measure the collagen fibril diameter of leather from a range of animals, including sheep and cattle, that had a range of tear strengths. SAXS data were fit to a cylinder model. The collagen fibril diameter and tear strength were found to be correlated in bovine leather (r(2) = 0.59; P = 0.009), with stronger leather having thicker fibrils. There was no correlation between orientation index, i.e., fibril alignment, and fibril diameter for this data set. Ovine leather showed no correlation between tear strength and fibril diameter, nor was there a correlation across a selection of other animal leathers. The findings presented here suggest that there may be a different structural motif in skin compared with tendon, particularly ovine skin or leather, in which the diameter of the individual fibrils contributes less to strength than fibril alignment does.

  14. [Obesity as a risk factor for atrial fibrillation].

    Science.gov (United States)

    Duraj, Iwona; Broncel, Marlena

    2016-01-01

    Atrial fibrillation (AF) and obesity is a growing problem of public health both in Poland and in the whole world. AF risk factors may be summarized as elderliness, male sex, smoking, hypertension, diabetes, obesity, coronary heart disease, heart failure, valvular heart disease, cardiac surgery. Once obesity is an independent, potentially modifiable risk factor for AF. The connection between obesity and atrial fibrillation is very up-to-date because of incremental prevalence, almost epidemic of obesity in the whole world. The probability of AF among obese patients increases with concomitant obstructive sleep apnea. Regardless many researches it hasn't been assessed yet how obesity itself predisposes to AF. It could be an effect of change in the atrial anatomy, the rise of atrial pressure, mechanical stretch, interstitial atrial fibrosis and disruption of atrial electric integrity. A great role is ascribed to inflammation, especially proinflammatory cytokines increased by adipocites of left atrial epicardial adiposity.

  15. Formation and properties of whey protein fibrils

    NARCIS (Netherlands)

    Kroes-Nijboer, A.

    2011-01-01

    Protein fibrils are threadlike aggregates that are about one molecule thick and more than thousand molecules long. Due to their threadlike structure they could potentially be used to form meat-like structures. Protein fibrils can be produced from milk protein and plant protein, opening opportunities

  16. Viscoelastic behavior of discrete human collagen fibrils

    DEFF Research Database (Denmark)

    2010-01-01

    on the strain. The slope of the viscous response showed a strain rate dependence corresponding to a power function of powers 0.242 and 0.168 for the two patellar tendon fibrils, respectively. In conclusion, the present work provides direct evidence of viscoelastic behavior at the single fibril level, which has...

  17. PAROXYSMAL ATRIAL FIBRILLATION: CHOICE OF CARDIOVERSION THERAPY

    Directory of Open Access Journals (Sweden)

    B. A. Tatarskii

    2007-01-01

    Full Text Available Characteristics and classification of different patterns of paroxysmal atrial fibrillation are presented. Main indications to restoration of sinus rhythm are discussed. The features of main medications used to terminate of atrial fibrillation are given. The choice of antiarrhythmic drug is considerate. Necessity of individual approach to therapy tactics is proved.

  18. Viscoelastic behavior of discrete human collagen fibrils

    DEFF Research Database (Denmark)

    Svensson, René; Hassenkam, Tue; Hansen, Philip

    2010-01-01

    Whole tendon and fibril bundles display viscoelastic behavior, but to the best of our knowledge this property has not been directly measured in single human tendon fibrils. In the present work an atomic force microscopy (AFM) approach was used for tensile testing of two human patellar tendon fibr...

  19. Graphene oxide strongly inhibits amyloid beta fibrillation

    NARCIS (Netherlands)

    Mahmoudi, Morteza; Akhavan, Omid; Ghavami, Mahdi; Rezaee, Farhad; Ghiasi, Seyyed Mohammad Amin

    2012-01-01

    Since amyloid beta fibrillation (AbF) plays an important role in the development of neurodegenerative diseases, we investigated the effect of graphene oxide (GO) and their protein-coated surfaces on the kinetics of Ab fibrillation in the aqueous solution. We showed that GO and their protein-covered

  20. Fibril assembly in whey protein mixtures

    NARCIS (Netherlands)

    Bolder, S.G.

    2007-01-01

    The objective of this thesis was to study fibril assembly in mixtures of whey proteins. The effect of the composition of the protein mixture on the structures and the resulting phase behaviour was investigated. The current work has shown that beta-lactoglobulin is responsible for the fibril assembly

  1. Machbarkeit und Effizienz einer extramuralen Nachsorge von Patienten mit dekompensierter Herzinsuffizienz - das Tiroler Modell

    Directory of Open Access Journals (Sweden)

    Pölzl G

    2007-01-01

    Full Text Available Dekompensierte Herzinsuffizienz ist die häufigste Ursache für stationäre Behandlung bei älteren Patienten. Die Wiederaufnahmerate innerhalb der ersten Monate beträgt bis zu 50 %. Durch ein umfassendes Patientenmanagement kann die Zahl der Krankenhauswiederaufnahmen reduziert werden. In der vorliegenden Pilotstudie sollen neben Machbarkeit und Effizienz auch die ökonomischen Konsequenzen einer auf den Großraum Innsbruck zugeschnittenen Ambulanz-basierten Heimbetreuung von älteren Patienten mit Herzinsuffizienz (HI durch speziell geschultes Pflegepersonal untersucht werden. Von Juli bis September 2003 wurden 17 Patienten, die wegen dekompensierter HI an der Universitätsklinik Innsbruck stationär behandelt wurden, in die Studie eingeschlossen. Nach intensiver Schulung durch speziell ausgebildete "HI-Schwestern" und Therapieoptimierung in der HI-Ambulanz wurden acht Patienten einer Interventionsgruppe und neun Patienten einer Kontrollgruppe randomisiert zugeordnet. Patienten der Interventionsgruppe wurden nach der Entlassung und in weiterer Folge in variablen Abständen von der "HI-Schwester" zu Hause besucht und die Therapie in Absprache mit der HI-Ambulanz angepaßt. Patienten der Kontrollgruppe wurden dem niedergelassenen Arzt zur weiteren Betreuung zugewiesen. Die Wiederaufnahmerate innerhalb von sechs Monaten betrug in der Interventionsgruppe 37 %, in der Kontrollgruppe 78 % (p 0,05. Die Zeit bis zur Wiederaufnahme (127 ± 24 vs. 84 ± 23 Tage war in der Interventionsgruppe tendenziell länger als in der Kontrollgruppe. Ebenso zeigte sich in der Interventionsgruppe nach sechs Monaten ein Trend zu einer verbesserten neurohumoralen Therapie. Die Reduktion der Krankenhauswiederaufnahmen ist nach Abzug der Kosten für die HI-Schwester mit einer Kosteneinsparung von € 2266/Patient/Jahr verbunden. Auf das gesamte Bundesland Tirol hochgerechnet würde ein derartiges Hybrid-Betreuungsmodell eine Kosteneinsparung von ca. € 1,172.820 j

  2. Modeling generic aspects of ideal fibril formation

    CERN Document Server

    Michel, Denis

    2016-01-01

    Many different proteins self-aggregate into insoluble fibrils growing apically by reversible addition of elementary building blocks. But beyond this common principle, the modalities of fibril formation are very disparate, with various intermediate forms which can be reshuffled by minor modifications of physico-chemical conditions or amino-acid sequences. To bypass this complexity, the multifaceted phenomenon of fibril formation is reduced here to its most elementary principles defined for a linear prototype of fibril. Selected generic features, including nucleation, elongation and conformational recruitment, are modeled using minimalist hypotheses and tools, by separating equilibrium from kinetic aspects and in vitro from in vivo conditions. These reductionist approaches allow to bring out known and new rudiments, including the kinetic and equilibrium effects of nucleation, the dual influence of elongation on nucleation, the kinetic limitations on nucleation and fibril numbers and the accumulation of complexe...

  3. Atrial fibrillation in patients with ischemic stroke

    DEFF Research Database (Denmark)

    Thygesen, Sandra Kruchov; Frost, Lars; Eagle, Kim A;

    2009-01-01

    BACKGROUND: Atrial fibrillation is a major risk factor for ischemic stroke. However, the prognostic impact of atrial fibrillation among patients with stroke is not fully clarified. We compared patient characteristics, including severity of stroke and comorbidity, quality of in-hospital care...... and outcomes in a cohort of first-time ischemic stroke patients with and without atrial fibrillation. METHODS: Based on linkage of public medical databases, we did a population-based follow-up study among 3,849 stroke patients from the County of Aarhus, Denmark admitted in the period of 2003......-2007 and prospectively registered in the Danish National Indicator Project. RESULTS: Atrial fibrillation was associated with an adverse prognostic profile but not with an overall poorer quality of in-hospital care. Patients with atrial fibrillation had a longer total length of stay (median: 15 vs 9 days), and were...

  4. Molecular basis for insulin fibril assembly

    Energy Technology Data Exchange (ETDEWEB)

    Ivanova, Magdalena I.; Sievers, Stuart A.; Sawaya, Michael R.; Wall, Joseph S.; Eisenberg, David; (HHMI); (BNL)

    2009-12-01

    In the rare medical condition termed injection amyloidosis, extracellular fibrils of insulin are observed. We found that the segment of the insulin B-chain with sequence LVEALYL is the smallest segment that both nucleates and inhibits the fibrillation of full-length insulin in a molar ratio-dependent manner, suggesting that this segment is central to the cross-{beta} spine of the insulin fibril. In isolation from the rest of the protein, LVEALYL forms microcrystalline aggregates with fibrillar morphology, the structure of which we determined to 1 {angstrom} resolution. The LVEALYL segments are stacked into pairs of tightly interdigitated {beta}-sheets, each pair displaying the dry steric zipper interface typical of amyloid-like fibrils. This structure leads to a model for fibrils of human insulin consistent with electron microscopic, x-ray fiber diffraction, and biochemical studies.

  5. Nanoscale scraping and dissection of collagen fibrils.

    Science.gov (United States)

    Wenger, M P E; Horton, M A; Mesquida, P

    2008-09-24

    The main function of collagen is mechanical, hence there is a fundamental scientific interest in experimentally investigating the mechanical and structural properties of collagen fibrils on the nanometre scale. Here, we present a novel atomic force microscopy (AFM) based scraping technique that can dissect the outer layer of a biological specimen. Applied to individual collagen fibrils, the technique was successfully used to expose the fibril core and reveal the presence of a D-banding-like structure. AFM nanoindentation measurements of fibril shell and core indicated no significant differences in mechanical properties such as stiffness (reduced modulus), hardness, adhesion and adhesion work. This suggests that collagen fibrils are mechanically homogeneous structures. The scraping technique can be applied to other biological specimens, as demonstrated on the example of bacteria.

  6. Chondroitin Sulfate Perlecan Enhances Collagen Fibril Formation

    DEFF Research Database (Denmark)

    Kvist, A. J.; Johnson, A. E.; Mörgelin, M.

    2006-01-01

    produced in the presence of perlecan. Interestingly, the enhancement of collagen fibril formation is independent on the core protein and is mimicked by chondroitin sulfate E but neither by chondroitin sulfate D nor dextran sulfate. Furthermore, perlecan chondroitin sulfate contains the 4,6-disulfated......Inactivation of the perlecan gene leads to perinatal lethal chondrodysplasia. The similarity to the phenotypes of the Col2A1 knock-out and the disproportionate micromelia mutation suggests perlecan involvement in cartilage collagen matrix assembly. We now present a mechanism for the defect...... in collagen type II fibril assembly by perlecan-null chondrocytes. Cartilage perlecan is a heparin sulfate or a mixed heparan sulfate/chondroitin sulfate proteoglycan. The latter form binds collagen and accelerates fibril formation in vitro, with more defined fibril morphology and increased fibril diameters...

  7. Medienpädagogik und Informatik. Zur Notwendigkeit einer Neubestimmung der Rolle digitaler Medien in Bildungsprozessen

    Directory of Open Access Journals (Sweden)

    Heidi Schelhowe

    2006-03-01

    Full Text Available Die Notwendigkeit eines grundlegenden Wandels des Bildungswesens in Deutschland ist kaum umstritten. Dass eine Gesellschaft, die sich selbst in epochalen Veränderungsprozessen der Umwälzung von einer Industriegesellschaft zu einer Informations- oder Wissensgesellschaft sieht, ihre Bildungsvorstellungen nicht an den alten Einschätzungen und Werten ausrichten kann, liegt nahe. Was jedoch sind die zentralen Ideen für eine solche Veränderung? Wo knüpfen sie an? Welchen Ballast müssen sie über Bord werfen? Wie und wo können wir Anhaltspunkte dafür finden, wie Lernen für die Zukunft aussehen kann?
Im vorliegenden Beitrag soll es um die Frage gehen, welche Rolle Digitale Technologien in diesen Veränderungsprozessen spielen und spielen könnten.

  8. Zur Rekonstruktion einer Typologie jugendlichen Medienhandelns gemäß dem Leitbild der Triangulation

    Directory of Open Access Journals (Sweden)

    Klaus Peter Treumann

    2017-09-01

    Full Text Available Die im Folgenden dargestellten Ergebnisse sind im Rahmen des von der DFG geförderten Forschungsprojekts „Eine Untersuchung zum Mediennutzungsverhalten 12- bis 20-Jähriger und zur Entwicklung von Medienkompetenz im Jugendalter“ entstanden, das gemeinsam von Klaus Peter Treumann, Uwe Sander und Dorothee Meister geleitet wird. Das Forschungsprojekt untersucht das Medienhandeln Jugendlicher sowohl hinsichtlich Neuer als auch alter Medien. Zum einen fragen wir dabei nach den Ausprägungen von Medienkompetenz in verschiedenen Dimensionen und zum anderen konzentrieren wir uns auf die Entwicklung einer empirisch fundierten Typologie jugendlichen Medienhandelns. Methodologisch ist die Untersuchung an dem Leitbild der Triangulation orientiert und kombiniert qualitative und quantitative Zugänge zum Forschungsfeld in Form von Gruppendiskussionen, leitfadengestützten Einzelinterviews und einer Repräsentativerhebung.

  9. Fibril-forming motifs are essential and sufficient for the fibrillization of human Tau.

    Science.gov (United States)

    Meng, Sheng-Rong; Zhu, Ying-Zhu; Guo, Tong; Liu, Xiao-Ling; Chen, Jie; Liang, Yi

    2012-01-01

    The misfolding of amyloidogenic proteins including human Tau protein, human prion protein, and human α-synuclein is involved in neurodegenerative diseases such as Alzheimer disease, prion disease, and Parkinson disease. Although a lot of research on such amyloidogenic proteins has been done, we do not know the determinants that drive these proteins to form fibrils and thereby induce neurodegenerative diseases. In this study, we want to know the role of fibril-forming motifs from such amyloidogenic proteins in the fibrillization of human Tau protein. As evidenced by thioflavin T binding and turbidity assays, transmission electron microscopy, and circular dichroism, fibril-forming motifs are essential and sufficient for the fibrillization of microtubule-associated protein Tau: only when both of its fibril-forming motifs, PHF6 and PHF6*, are deleted can recombinant human Tau fragment Tau(244-372) lose its ability to form fibrils, and the insertion of unrelated fibril-forming motifs from other amyloidogenic proteins, such as human prion protein, yeast prion protein, human α-synuclein, and human amyloid β, into the disabled Tau protein can retrieve its ability to form fibrils. Furthermore, this retrieval is independent of the insertion location on Tau(244-372). We demonstrate for the first time that insertion of fibril-forming motifs can replace PHF6/PHF6* motifs, driving human Tau protein to form fibrils with different morphologies and different kinetic parameters. Our results suggest that fibril-forming motifs play a key role in the fibrillization of human Tau protein and could be the determinants of amyloidogenic proteins tending to misfold, thereby causing the initiation and development of neurodegenerative diseases. Our study also touches on the importance of amyloid "strains": changes to the amyloidgenic driver region results in altered structural morphologies at the macromolecular level.

  10. Fibril-forming motifs are essential and sufficient for the fibrillization of human Tau.

    Directory of Open Access Journals (Sweden)

    Sheng-Rong Meng

    Full Text Available BACKGROUND: The misfolding of amyloidogenic proteins including human Tau protein, human prion protein, and human α-synuclein is involved in neurodegenerative diseases such as Alzheimer disease, prion disease, and Parkinson disease. Although a lot of research on such amyloidogenic proteins has been done, we do not know the determinants that drive these proteins to form fibrils and thereby induce neurodegenerative diseases. In this study, we want to know the role of fibril-forming motifs from such amyloidogenic proteins in the fibrillization of human Tau protein. METHODOLOGY/PRINCIPAL FINDINGS: As evidenced by thioflavin T binding and turbidity assays, transmission electron microscopy, and circular dichroism, fibril-forming motifs are essential and sufficient for the fibrillization of microtubule-associated protein Tau: only when both of its fibril-forming motifs, PHF6 and PHF6*, are deleted can recombinant human Tau fragment Tau(244-372 lose its ability to form fibrils, and the insertion of unrelated fibril-forming motifs from other amyloidogenic proteins, such as human prion protein, yeast prion protein, human α-synuclein, and human amyloid β, into the disabled Tau protein can retrieve its ability to form fibrils. Furthermore, this retrieval is independent of the insertion location on Tau(244-372. CONCLUSIONS/SIGNIFICANCE: We demonstrate for the first time that insertion of fibril-forming motifs can replace PHF6/PHF6* motifs, driving human Tau protein to form fibrils with different morphologies and different kinetic parameters. Our results suggest that fibril-forming motifs play a key role in the fibrillization of human Tau protein and could be the determinants of amyloidogenic proteins tending to misfold, thereby causing the initiation and development of neurodegenerative diseases. Our study also touches on the importance of amyloid "strains": changes to the amyloidgenic driver region results in altered structural morphologies at the

  11. Molecular insights into the reversible formation of tau protein fibrils.

    Science.gov (United States)

    Luo, Yin; Dinkel, Paul; Yu, Xiang; Margittai, Martin; Zheng, Jie; Nussinov, Ruth; Wei, Guanghong; Ma, Buyong

    2013-05-04

    We computationally and experimentally showed that tau protein fibrils can be formed at high temperature. When cooled, the fibrils dissociate back to monomers. Heparin promotes tau fibril formation and prevents its reversion. Our results revealed the physicochemical mechanism of reversible formation of tau fibrils.

  12. Anticoagulation therapy for atrial fibrillation.

    Science.gov (United States)

    Hylek, Elaine M

    2013-03-01

    Atrial fibrillation (AF) is the most common significant cardiac rhythm disorder, and its prevalence is increasing worldwide. Atrial fibrillation confers a fivefold increased risk of stroke, and these strokes are associated with significant mortality and disability. The vitamin K antagonist, warfarin, has been the mainstay of anticoagulant therapy for patients with AF, reducing the risk of stroke by 65%. Despite its efficacy, warfarin remains underused in clinical practice because of its variable dose response, diet and medication interactions, and need for frequent monitoring. Stroke prevention in AF has entered an exciting therapeutic era with new classes of targeted anticoagulants that avoid the many pitfalls of the vitamin K antagonists. Dabigatran, an oral thrombin inhibitor, and the factor Xa inhibitors, rivaroxaban and apixaban, have demonstrated efficacy for stroke prevention and a reduced risk of intracranial hemorrhage relative to warfarin. Translating the efficacy of clinical trials into effective use of these novel agents in clinical practice will require an understanding of their pharmacokinetic profiles, dose selection, and management in select clinical situations.

  13. Neuronal Classification of Atria Fibrillation

    Directory of Open Access Journals (Sweden)

    Mohamed BEN MESSAOUD

    2008-06-01

    Full Text Available Motivation. In medical field, particularly the cardiology, the diagnosis systems constitute the essential domain of research. In some applications, the traditional methods of classification present some limitations. The neuronal technique is considered as one of the promising algorithms to resolve such problem.Method. In this paper, two approaches of the Artificial Neuronal Network (ANN technique are investigated to classify the heart beats which are Multi Layer Perception (MLP and Radial Basis Function (RBF. A calculation algorithm of the RBF centers is proposed. For the Atria Fibrillation anomalies, an artificial neural network was used as a pattern classifier to distinguish three classes of the cardiac arrhythmias. The different classes consist of the normal beats (N, the Arrhythmia (AFA and Tachycardia (TFA Atria Fibrillation cases. The global and the partition classifier are performed. The arrhythmias of MIT-BIH database are analyzed. The ANN inputs are the temporal and morphological parameters deduced from the electrocardiograph.Results. The simulation results illustrate the performances of the studied versions of the neural network and give the fault detection rate of the tested data, a rate of classification reaching the 3.7%.Conclusion. This system can constitute a mesh in a chain of automated diagnosis and can be a tool for assistance for the classification of the cardiac anomalies in the services of urgencies before the arrival of a qualified personal person.

  14. Personal Branding von Musikern: Wie man im Musikgeschäft zu einer starken Marke wird

    OpenAIRE

    Schmidt, Holger J.; Horländer, Lisa

    2011-01-01

    In Zeiten einer hohen Reizüberflutung konkurrieren nicht nur Unternehmen sowie deren Produkte und Dienstleistungen um die Aufmerksamkeit ihrer Zielgruppen. Auch Personen des öffentlichen Lebens, z.B. Politiker, Künstler oder Wissenschaftler, stehen im Wettbewerb zueinander. Eine Möglichkeit, sich als Person dauerhaft von Anderen abzugrenzen und langfristig erfolgreich zu sein, bietet der Ansatz des Personal Branding. Unter dem Begriff Personal Branding, welches mitunter auch als Human Brandin...

  15. Untersuchungen zur Bedeutung anthelminthischer Behandlungen bei der Auslösung von Symptomen einer larvalen Cyathostominose

    OpenAIRE

    Steinbach, Tanja

    2003-01-01

    Im Rahmen dieser Arbeit wird untersucht, ob bei Pferden durch die Gabe von Anthelminthika Symptome einer larvalen Cyathostominose ausgelöst werden können. Im Zentrum des Interesses stehen dabei die Anthelminthika Moxidectin und Fenbendazol, die aufgrund ihrer larviziden Wirksamkeit als Mittel der ersten Wahl für die kausale Therapie und Metaphylaxe der larvalen Cyathostominose angesehen werden. Der Versuch wird an 24 Ponyfohlen durchgeführt, die in die folgenden Gruppen unterteilt werden...

  16. Vom Lohn des Wartens und vom Preis der Hast: Anmerkungen zu einer aktivistischen Klimapolitik

    OpenAIRE

    Schönfelder, Bruno

    2012-01-01

    Dieser Aufsatz argumentiert, dass die deutsche EE-Förderung auf einer falschen Konzeption beruht. Sie hat sich vorwiegend befehlswirtschaftlicher Methoden bedient und eine Staatsschuldillusion zu erzeugen versucht. Es verwundert infolgedessen nicht, dass enorme Kosten entstanden sind, wohingegen die Nutzen bescheiden blieben. Die wichtigste Ausnahme hiervon sind die Biotreibstoffe. Sie haben sich besser entwickelt als ihre Kritiker meinen. Die übliche Rechtfertigung der EE-Förderung, die ihre...

  17. Versorgung kindlicher unilateraler Gehörgangsatresie mit einer Vibrant Soundbridge - eine Pilotstudie

    OpenAIRE

    Vaerst, B; Almahameed, A; Leinung, M; Zaretsky, Y; Lange, B.; Stöver, T; Hey, C

    2013-01-01

    Hintergrund: Die Versorgung einer unilateralen Gehörgangsatresie (GA) stellt bei Kindern einen hohen Anspruch an Arzt und Akustiker. Konservative Knochenleitungshörsysteme werden häufig nur eingeschränkt toleriert. Eine Alternative bildet seit 2009 das Mittelohr-Implantat Vibrant Soundbridge (VSB), Med El. Dieses ist bislang weltweit erst bei ca. 100 Kindern eingesetzt worden, nur wenige unter dem 6. Lebensjahr.Ziel dieser Studie ist die Erfassung von Versorgungszufriedenheit und -qualität m...

  18. Präoperative Vorhersge der Rezidivrate des klinisch lokalisierten Prostatakarzinoms nach einer radikalen Prostatektomie

    Directory of Open Access Journals (Sweden)

    Graefen M

    1999-01-01

    Full Text Available Die radikale Prostatektomie scheint die zur Zeit effektivste Therapie des klinisch lokalisierten Prostatakarzinoms zu sein. Dennoch liegt die Rezidivrate bei bis zu 40 % der operierten Patienten. Mit dieser Arbeit wurde anhand präoperativer Befunde ein Algorithmus entwickelt, mit welchem die Prognose des klinisch lokalisierten Prostatakarzinoms bereits vor einer operativen Therapie abgeschätzt werden kann. Hierzu wurden multiple präoperative Befunde, welche bei der Diagnose des Prostatakarzinoms erhoben werden, bezüglich ihres Einflusses auf einen PSA-Progress nach radikaler Prostatektomie geprüft. Dies erfolgte mittels einer univariaten Kaplan-Meier Analyse sowie einer multivariaten Statistik (Cox-Regression und CART-Analyse. Schwerpunkt bildete hierbei die Einbeziehung der Ergebnisse der systematischen Sextanten-Biopsie der Prostata. Alle präoperativen Befunde haben in der univariaten Kaplan-Meier Analyse einen signifikanten Einfluß auf ein PSA-Rezidiv. In der Cox-Regression hatte der Anteil an niedrigdifferenziertem Prostatakarzinom den größten Einfluß auf das Auftreten eines Tumorprogresses, gefolgt von der Anzahl der positiven Stanzen in der Biopsie und dem präoperativen PSA-Wert; alle anderen Parameter hatten keinen unabhängig signifikanten Einfluß auf den Tumorprogress. Mittels der zusätzlich durchgeführten CART Analyse konnten verschiedene Risikogruppen definiert werden, deren Rezidivrisiko bei 3 % für Patienten mit geringem Rezidivrisiko sowie 80 % für solche mit einem hohen Rezidivrisiko 2 Jahre nach der Operation betrug. Der niedrigdifferenzierte Tumoranteil hat somit den größten Einfluß auf die Prognose eines klinisch lokalisierten Prostatakarzinoms. Anhand der präsentierten CART-Analysen wurden einfach anwendbare Entscheidungsbäume entwickelt, mit denen eine Abschätzung des Therapieerfolges des klinisch lokalisierten Prostatakarzinoms bereits vor einer Operation möglich ist.

  19. Mögliche Auswirkungen einer Ausweitung der Gentechnik-Kennzeichnungspflicht auf Lebensmittel tierischen Ursprungs

    OpenAIRE

    Peter, Günter; Krug, Oliver; Bendiek, Joachim; Stolz, Andrea

    2014-01-01

    Lebensmittel müssen auf Grundlage bestehender EU-Vorschriften gekennzeichnet werden, wenn das Lebensmittel oder einer der verwendeten Inhaltsstoffe gentechnisch verändert oder aus einem gentechnisch veränderten Organismus hergestellt ist. Dabei ist es unerheblich, ob die gentechnische Veränderung im Produkt nachgewiesen werden kann. Aktuell nicht gekennzeichnet werden müssen Lebensmittel von Tieren, die mit gentechnisch verändertem Futter gefüttert wurden. Die Regierungsparteien in Deutschlan...

  20. Validierung einer deutschen Version der “Culturally Responsive Classroom Management Self-Efficacy Scale"

    OpenAIRE

    Civitillo, Sauro; Juang, Linda; Schachner, Maja; Börnert, Moritz

    2016-01-01

    Die Culturally Responsive Classroom Management Self-Efficacy Scale (CRCMSES; Siwatu, Putman, Starker-Glass & Lewis, 2015) stellt ein neues Instrument zur Erfassung der Selbstwirksamkeit hinsichtlich kultursensiblen Classroom Managements von Lehrkräften dar. Die vorliegende Studie hat zum Ziel, die eindimensionale Struktur einer für den deutschsprachigen Raum adaptierten Version des CRCMSES mit Hilfe von explorativen und konfirmatorischen Faktorenanalysen zu bestätigen. Dazu wurde das Instrume...

  1. Zur Konzeption kritischer Stadtforschung. Ansätze jenseits einer Eigenlogik der Städte

    Directory of Open Access Journals (Sweden)

    Jan Kemper

    2013-06-01

    Full Text Available Kritische Stadtforschung dient in Gestalt der „kritischen Stadtsoziologie“ gegenwärtig als Negativfolie für jene Stadtforschungsperspektive, die mit dem Postulat einer „Eigenlogik der Städte“ (EdS antritt. Eine (Selbst-Verständigung über konzeptionelle Grundlagen und forschungsstrategische Absichten einer kritischen Stadtforschung dagegen gibt es kaum. Ausgehend von dieser Beobachtung ist es das Ziel dieses Beitrags, zu einer Konturierung kritischer Stadtforschung beizutragen. Dafür skizzieren wir zunächst Eckpunkte der EdS-Perspektive. Anschließend wird ein Blick zurück auf den Klassiker Die Lage der arbeitenden Klasse in England (1845 von Friedrich Engels geworfen. Daran verdeutlichen wir drei Schritte in der Etablierung einer kritischen Haltung in der Stadtforschung: die Berücksichtigung der historisch-sozialen Voraussetzungen für gegenwärtige Stadtentwicklungsprozesse, die Analyse der städtischen Raum- und Sozialverhältnisse als krisen- und konfliktvermittelte und deshalb als dynamische Verhältnisse sowie die Konzeptionierung dieser Verhältnisse als veränderbar. An drei wiederkehrenden Diskussionsfeldern sozialwissenschaftlicher Stadtforschung schließlich verfolgen wir, wie einerseits die EdS-Perspektive sich dieser Themen annimmt und wie andererseits eine kritische Haltung im Umgang mit diesen Themen eingenommen werden kann. Für eine kritische Stadtforschung schlagen wir vor, (a „Stadt“ nicht als dauerhaft definiert und nicht als erklärend für sozialräumliche Verhältnisse zu begreifen, (b auch Städte als Räume zu konzipieren, die sich im gegenseitigen Wechselverhältnis mit Gesellschaft konstituieren, (c mit einem Konzept von Differenz, das Unterschiede sozial erklärt, zu arbeiten, wenn Städte als einzigartig erlebte Orte analysiert werden sollen.

  2. Bibliotheken: Wir öffnen Daten. Zum Stand der Entwicklung einer offenen Dateninfrastruktur

    Directory of Open Access Journals (Sweden)

    Adrian Pohl

    2014-12-01

    Full Text Available In den letzten Jahren haben sich – gerade in Deutschland – viele Bibliotheken und insbesondere Verbundzentralen entschlossen, bibliothekarische Daten unter einer offenen Lizenz zu publizieren und/oder als Linked Data aufzubereiten. Dieser Beitrag versucht, diese Aktivitäten in einem größeren Kontext zu sehen, indem er Open Data als eines von mehreren Elementen einer „offenen Dateninfrastruktur“ versteht. Es werden sieben Elemente einer Dateninfrastruktur skizziert und eingeschätzt, wie offen die einzelnen Elemente gegenwärtig in Deutschland sind. Abschließend wird am Beispiel von (Open Discovery vorgeführt, wie offene Ansätze bestehende Probleme beheben könnten und welche Handlungsmöglichkeiten es gibt. During the last years many libraries and especially library service centers have decided to publish library data under an open license and/or to expose it as linked data. This paper tries to put these activities in a bigger context by viewing open data as one element of an open data infrastructure. Seven elements of data infrastuctures are outlined and their approximate level of openness in Germany is assessed. Finally, it is demonstrated – using (open discovery as an example – how open approaches can fix existing problems and which possibilities there are for practical actions.

  3. Effect of stirring and seeding on whey protein fibril formation.

    Science.gov (United States)

    Bolder, Suzanne G; Sagis, Leonard M C; Venema, Paul; van der Linden, Erik

    2007-07-11

    The effect of stirring and seeding on the formation of fibrils in whey protein isolate (WPI) solutions was studied. More fibrils of a similar length are formed when WPI is stirred during heating at pH 2 and 80 degrees C compared to samples that were heated at rest. Addition of seeds did not show an additional effect compared to samples that were stirred. We propose a model for fibril formation, including an activation, nucleation, growth, and termination step. The activation and nucleation steps are the rate-determining steps. Fibril growth is relatively fast but terminates after prolonged heating. Two processes that possibly induce termination of fibril growth are hydrolysis of nonassembled monomers and inactivation of the growth ends of the fibrils. Stirring may break up immature fibrils, thus producing more active fibrils. Stirring also seems to accelerate the kinetics of fibril formation, resulting in an increase of the number of fibrils formed.

  4. Magnetite nanoparticle interactions with insulin amyloid fibrils

    Science.gov (United States)

    Chen, Yun-Wen; Chang, Chiung-Wen; Hung, Huey-Shan; Kung, Mei-Lang; Yeh, Bi-Wen; Hsieh, Shuchen

    2016-10-01

    Accumulation of amyloid fibrils is one of the likely key factors leading to the development of Alzheimer’s disease and other amyloidosis associated diseases. Magnetic nanoparticles (NPs) have been developed as promising medical materials for many medical applications. In this study, we have explored the effects of Fe3O4 NPs on the fibrillogenesis process of insulin fibrils. When Fe3O4 NPs were co-incubated with insulin, Fe3O4 NPs had no effect on the structural transformation into amyloid-like fibrils but had higher affinity toward insulin fibrils. We demonstrated that the zeta potential of insulin fibrils and Fe3O4 NPs were both positive, suggesting the binding forces between Fe3O4 NPs and insulin fibrils were van der Waals forces but not surface charge. Moreover, a different amount of Fe3O4 NPs added had no effect on secondary structural changes of insulin fibrils. These results propose the potential use of Fe3O4 NPs as therapeutic agents against diseases related to protein aggregation or contrast agents for magnetic resonance imaging.

  5. Atrial fibrillation and survival in colorectal cancer

    Directory of Open Access Journals (Sweden)

    Justin Timothy A

    2004-11-01

    Full Text Available Abstract Background Survival in colorectal cancer may correlate with the degree of systemic inflammatory response to the tumour. Atrial fibrillation may be regarded as an inflammatory complication. We aimed to determine if atrial fibrillation is a prognostic factor in colorectal cancer. Patients and methods A prospective colorectal cancer patient database was cross-referenced with the hospital clinical-coding database to identify patients who had underwent colorectal cancer surgery and were in atrial fibrillation pre- or postoperatively. Results A total of 175 patients underwent surgery for colorectal cancer over a two-year period. Of these, 13 patients had atrial fibrillation pre- or postoperatively. Atrial fibrillation correlated with worse two-year survival (p = 0.04; log-rank test. However, in a Cox regression analysis, atrial fibrillation was not significantly associated with survival. Conclusion The presence or development of atrial fibrillation in patients undergoing surgery for colorectal cancer is associated with worse overall survival, however it was not found to be an independent factor in multivariate analysis.

  6. Characterization of tau fibrillization in vitro.

    Science.gov (United States)

    Xu, Shaohua; Brunden, Kurt R; Trojanowski, John Q; Lee, Virginia M-Y

    2010-03-01

    The assembly of tau proteins into paired helical filaments, the building blocks of neurofibrillary tangles, is linked to neurodegeneration in Alzheimer's disease and related tauopathies. A greater understanding of this assembly process could identify targets for the discovery of drugs to treat Alzheimer's disease and related disorders. By using recombinant human tau, we have delineated events leading to the conversion of normal soluble tau into tau fibrils. Atomic force microscopy and transmission electron microscopy methodologies were used to determine the structure of tau assemblies that formed when soluble tau was incubated with heparin for increasing lengths of time. Tau initially oligomerizes into spherical nucleation units of 18- to 21-nm diameter that appear to assemble linearly into nascent fibrils. Among the earliest tau fibrils are species that resemble a string of beads formed by linearly aligned spheres that with time seem to coalesce to form straight and twisted ribbon-like filaments, as well as paired helical filaments similar to those found in human tauopathies. An analysis of fibril cross sections at later incubation times revealed three fundamental axial structural features. By monitoring tau fibrillization, we showed that different tau filament morphologies coexist. Temporal changes in the predominant tau structural species suggest that tau fibrillization involves the generation of structural intermediates, resulting in the formation of tau fibrils with verisimilitude to their authentic human counterparts. 2010 The Alzheimer's Association. All rights reserved.

  7. "Neu lernen ist leichter als umlernen". Über die Schwierigkeiten einer bildungsgewohnten Gruppe, neue (mediale Partizipationsformen aufzubauen

    Directory of Open Access Journals (Sweden)

    Anna-Maria Kamin

    2011-10-01

    Full Text Available Das Internet bietet Lernenden vielfältige Möglichkeiten zur Wissensorganisation und -kommunikation in formalen und informellen Bildungskontexten. Bislang nutzen selbst bildungsaffine erwachsene Lerner diese unterstützenden Potenziale des Internets vielfach nur zurückhaltend. Dieser zögerliche Gebrauch zeigt sich auch dann, wenn die Implementierung virtuell vernetzter Applikationen in der Planung von den Lernenden von den Akteuren prinzipiell gefordert und begrüsst wird. Im Zentrum unseres Beitrags stehen mögliche Gründe und Bedingungen für diese vermeintlichen Widerstände und Problematiken bei der Integration des Partizipationsraums Internet für berufliche Lernprozesse. Grundlage für die Diskussion sind die Praxiserfahrungen und empirischen Ergebnisse einer explorativen Fall­studie mit einem ethisch beratenden Gremium. Die bisherige Bilanz des Projektvor­habens unterstreicht die Notwendigkeit, in diesem Kontext theoretische Konzepte zu Lernwiderständen, generationsspezifischen Aspekten, zur Mediendidaktik und zu Lerngewohnheiten und Transfer zu diskutieren. Die Ergebnisse belegen, dass digitale Lern- und Arbeitsformen unmittelbar an eingeschliffene Lernroutinen gebunden sind. Lernende benötigen Zeit, Raum, Anlässe und Struktur, um Handlungs- und Lernroutinen aufzubrechen und neue zu entwickeln. Nur so können digitale Partizipationsmöglichkeiten erfolgreich in den Arbeitsalltag integriert werden.

  8. The atrial fibrillation ablation pilot study

    DEFF Research Database (Denmark)

    Arbelo, Elena; Brugada, Josep; Hindricks, Gerhard

    2014-01-01

    AIMS: The Atrial Fibrillation Ablation Pilot Study is a prospective registry designed to describe the clinical epidemiology of patients undergoing an atrial fibrillation (AFib) ablation, and the diagnostic/therapeutic processes applied across Europe. The aims of the 1-year follow-up were to analyse...... tachycardia, and 4 patients died (1 haemorrhagic stroke, 1 ventricular fibrillation in a patient with ischaemic heart disease, 1 cancer, and 1 of unknown cause). CONCLUSION: The AFib Ablation Pilot Study provided crucial information on the epidemiology, management, and outcomes of catheter ablation of AFib...

  9. On fibrils and field lines: The nature of H$\\alpha$ fibrils in the solar chromosphere

    CERN Document Server

    Leenaarts, Jorrit; van der Voort, Luc Rouppe

    2015-01-01

    Observations of the solar chromosphere in the line-core of the \\Halpha\\ line show dark elongated structures called fibrils that show swaying motion. We performed a 3D radiation-MHD simulation of a network region, and computed synthetic \\Halpha\\ images from this simulation to investigate the relation between fibrils and the magnetic field lines in the chromosphere. The periods, amplitudes and phase-speeds of the synthetic fibrils are consistent with those observed. We analyse the relation between the synthetic fibrils and the field lines threading through them, and find that some fibrils trace out the same field line along the fibril's length, but there are also fibrils that sample different field lines at different locations along their length. Fibrils sample the same field lines on a time scale of $\\sim200$~s. This is shorter than their own lifetime. We analysed the evolution of the atmosphere along a number of field lines that thread through fibrils and find that they carry slow-mode waves that load mass in...

  10. Atrial Fibrillation During an Exploration Class Mission

    Science.gov (United States)

    Lipsett, Mark; Hamilton, Douglas; Lemery, Jay; Polk, James

    2011-01-01

    This slide presentation reviews a possible scenario of an astronaut having Atrial Fibrillation during a Mars Mission. In the case review the presentation asks several questions about the alternatives for treatment, medications and the ramifications of the decisions.

  11. Aggregate geometry in amyloid fibril nucleation

    CERN Document Server

    Irbäck, A; Linnemann, N; Linse, B; Wallin, S; 10.1103/PhysRevLett.110.058101

    2013-01-01

    We present and study a minimal structure-based model for the self-assembly of peptides into ordered beta-sheet-rich fibrils. The peptides are represented by unit-length sticks on a cubic lattice and interact by hydrogen bonding and hydrophobicity forces. By Monte Carlo simulations with >100,000 peptides, we show that fibril formation occurs with sigmoidal kinetics in the model. To determine the mechanism of fibril nucleation, we compute the joint distribution in length and width of the aggregates at equilibrium, using an efficient cluster move and flat-histogram techniques. This analysis, based on simulations with 256 peptides in which aggregates form and dissolve reversibly, shows that the main free-energy barriers that a nascent fibril has to overcome are associated with changes in width.

  12. Atrial Fibrillation and Stroke in Elderly Patients

    Directory of Open Access Journals (Sweden)

    Geetanjali Dang

    2016-11-01

    Full Text Available The increasing prevalence of stroke, with an estimated annual cost of $71.5 billion, has made it a major health problem that increases disability and death, particularly in patients with atrial fibrillation. Although advanced age and atrial fibrillation are recognized as strong risk factors for stroke, the basis for this susceptibility are not well defined. Aging or associated diseases are accompanied by changes in rheostatic, humoral, metabolic and hemodynamic factors that may contribute more to stroke predisposition than rhythm abnormality alone. Several thromboembolism-predisposing clinical characteristics and serum biomarkers with prognostic significance have been identified in patients with atrial fibrillation. Although anticoagulation decreases the risk of thromboembolism, management in the elderly remains complex due to major concerns about bleeding. New anticoagulants and nonpharmacologic strategies are helpful to reduce the risk of bleeding, particularly in older-elderly patients. Herein, we review the pathogenesis and management of select issues of thromboembolism in the elderly with atrial fibrillation.

  13. Amyloid fibrils compared to peptide nanotubes.

    Science.gov (United States)

    Zganec, Matjaž; Zerovnik, Eva

    2014-09-01

    Prefibrillar oligomeric states and amyloid fibrils of amyloid-forming proteins qualify as nanoparticles. We aim to predict what biophysical and biochemical properties they could share in common with better researched peptide nanotubes. We first describe what is known of amyloid fibrils and prefibrillar aggregates (oligomers and protofibrils): their structure, mechanisms of formation and putative mechanism of cytotoxicity. In distinction from other neuronal fibrillar constituents, amyloid fibrils are believed to cause pathology, however, some can also be functional. Second, we give a review of known biophysical properties of peptide nanotubes. Finally, we compare properties of these two macromolecular states side by side and discuss which measurements that have already been done with peptide nanotubes could be done with amyloid fibrils as well.

  14. [Cardiac rehabilitation in patients with atrial fibrillation].

    Science.gov (United States)

    Schlitt, Axel; Kamke, Wolfram; Guha, Manju; Haberecht, Olaf; Völler, Heinz

    2015-06-01

    The course of cardiac rehabilitation is often altered due to episodes of paroxysmal, predominantly postoperative atrial fibrillation. In symptomatic patients, a TEE-guided cardioversion - preferential DC shock - is indicated. In patients with persistent / permanent atrial fibrillation, a heart rate up to 110 / min and 170 / min at rest and during physical activity should, respectively, be tolerated. Therefore, training should not be quitted by heart rate but rather by load. The antithrombotic management is in addition a great task in treating patients with atrial fibrillation. With the exception of patients with a CHA2DS2-VASc-Score < 1, oral anticoagulation is indicated. Atrial fibrillation has little impact on social aspects, whereas the underlying heart disease and drug treatment (oral anticoagulation) has an important impact.

  15. Alcohol consumption and risk of atrial fibrillation

    DEFF Research Database (Denmark)

    Tolstrup, Janne Schurmann; Wium-Andersen, Marie Kim; Ørsted, David Dynnes

    2016-01-01

    BACKGROUND: The aim of this study was to test the hypothesis that alcohol consumption, both observational (self-reported) and estimated by genetic instruments, is associated with a risk of atrial fibrillation and to determine whether people with high cardiovascular risk are more sensitive towards...... register. As a measure of alcohol exposure, both self-reported consumption and genetic variations in alcohol metabolizing genes (ADH1B/ADH1C) were used as instrumental variables. The endpoint was admission to hospital for atrial fibrillation as recorded in a validated hospital register. RESULTS: A total...... of 3493 cases of atrial fibrillation occurred during follow-up. High alcohol consumption was associated with a risk of atrial fibrillation among men, but not among women. Among the men who drank 28-35 and 35+ drinks/week, the hazards ratios were 1.40 (95% confidence interval 1.09-1.80) and 1.62 (95...

  16. Influence of the stability of a fused protein and its distance to the amyloidogenic segment on fibril formation.

    Directory of Open Access Journals (Sweden)

    Anja Buttstedt

    Full Text Available Conversion of native proteins into amyloid fibrils is irreversible and therefore it is difficult to study the interdependence of conformational stability and fibrillation by thermodynamic analyses. Here we approached this problem by fusing amyloidogenic poly-alanine segments derived from the N-terminal domain of the nuclear poly (A binding protein PABPN1 with a well studied, reversibly unfolding protein, CspB from Bacillus subtilis. Earlier studies had indicated that CspB could maintain its folded structure in fibrils, when it was separated from the amyloidogenic segment by a long linker. When CspB is directly fused with the amyloidogenic segment, it unfolds because its N-terminal chain region becomes integrated into the fibrillar core, as shown by protease mapping experiments. Spacers of either 3 or 16 residues between CspB and the amyloidogenic segment were not sufficient to prevent this loss of CspB structure. Since the low thermodynamic stability of CspB (ΔG(D = 12.4 kJ/mol might be responsible for unfolding and integration of CspB into fibrils, fusions with a CspB mutant with enhanced thermodynamic stability (ΔG(D = 26.9 kJ/mol were studied. This strongly stabilized CspB remained folded and prevented fibril formation in all fusions. Our data show that the conformational stability of a linked, independently structured protein domain can control fibril formation.

  17. [Anticoagulation in atrial fibrillation - an update].

    Science.gov (United States)

    Antz, Matthias; Hullmann, Bettina; Neufert, Christian; Vocke, Wolfgang

    2008-12-01

    The correct anticoagulation regimen for prevention of thromboembolic events is essential in patients with atrial fibrillation. However, only a minority of patients receives anticoagulation according to the guidelines. The current guidelines are intended to make the indication for anticoagulation more simple and are summarized in the present article. This includes recommendations for chronic anticoagulation, prevention of thromboembolic events after cardioversion and in ablation of atrial fibrillation.

  18. Thermal denaturation behavior of collagen fibrils in wet and dry environment.

    Science.gov (United States)

    Suwa, Yosuke; Nam, Kwangwoo; Ozeki, Kazuhide; Kimura, Tsuyoshi; Kishida, Akio; Masuzawa, Toru

    2016-04-01

    We have developed a new minimally invasive technique--integrated low-level energy adhesion technique (ILEAT)--which uses heat, pressure, and low-frequency vibrations for binding living tissues. Because the adhesion mechanism of the living tissues is not fully understood, we investigated the effect of thermal energy on the collagen structure in living tissues using ILEAT. To study the effect of thermal energy and heating time on the structure of the collagen fibril, samples were divided in two categories-wet and dry. Further, atomic force microscopy was used to analyze the collagen fibril structure before and after heating. Results showed that collagen fibrils in water denatured after 1 minute at temperatures higher than 80 °C, while partial denaturation was observed at temperatures of 80 °C and a heating time of 1 min. Furthermore, complete denaturation was achieved after 90 min, suggesting that the denaturation rate is temperature and time dependent. Moreover, the collagen fibrils in dry condition maintained their native structure even after being heated to 120 °C for 90 min in the absence of water, which specifically suppressed denaturation. However, partial denaturation of collagen fibrils could not be prevented, because this determines the adhesion between the collagen molecules, and stabilizes tissue bonding.

  19. SDS-Induced Fibrillation of α-Synuclein

    DEFF Research Database (Denmark)

    Giehm, L.; Oliveira, Cristiano Luis Pinto De; Pedersen, J.S.;

    2010-01-01

    -stabilized micelles. Thus, fibrillation in this case occurs by a process of continuous accretion rather than by the rate-limiting accumulation of a distinct nucleus. The morphology of the SDS-induced fibrils does not exhibit the classical rod-like structures formed by αSN when aggregated by agitation in the absence......, and transmission electron microscopy to elucidate a fibrillation pathway that is remarkably different from the fibrillation pathway in the absence of SDS. Fibrillation occurs most extensively and most rapidly (starting within 45 min) under conditions where 12 SDS molecules are bound per αSN molecule, which is also...... of SDS. The SDS-induced fibrils have a flexible worm-like appearance, which can be converted into classical straight fibrils by continuous agitation. SDS-induced fibrillation represents an alternative and highly reproducible mechanism for fibrillation where protein association is driven by the formation...

  20. Laser-induced propagation and destruction of amyloid beta fibrils.

    Science.gov (United States)

    Yagi, Hisashi; Ozawa, Daisaku; Sakurai, Kazumasa; Kawakami, Toru; Kuyama, Hiroki; Nishimura, Osamu; Shimanouchi, Toshinori; Kuboi, Ryoichi; Naiki, Hironobu; Goto, Yuji

    2010-06-18

    The amyloid deposition of amyloid beta (Abeta) peptides is a critical pathological event in Alzheimer disease (AD). Preventing the formation of amyloid deposits and removing preformed fibrils in tissues are important therapeutic strategies against AD. Previously, we reported the destruction of amyloid fibrils of beta(2)-microglobulin K3 fragments by laser irradiation coupled with the binding of amyloid-specific thioflavin T. Here, we studied the effects of a laser beam on Abeta fibrils. As was the case for K3 fibrils, extensive irradiation destroyed the preformed Abeta fibrils. However, irradiation during spontaneous fibril formation resulted in only the partial destruction of growing fibrils and a subsequent explosive propagation of fibrils. The explosive propagation was caused by an increase in the number of active ends due to breakage. The results not only reveal a case of fragmentation-induced propagation of fibrils but also provide insights into therapeutic strategies for AD.

  1. Chirality and chiroptical properties of amyloid fibrils.

    Science.gov (United States)

    Dzwolak, Wojciech

    2014-09-01

    Chirality of amyloid fibrils-linear beta-sheet-rich aggregates of misfolded protein chains-often manifests in morphological traits such as helical twist visible in atomic force microscopy and in chiroptical properties accessible to vibrational circular dichroism (VCD). According to recent studies the relationship between molecular chirality of polypeptide building blocks and superstructural chirality of amyloid fibrils may be more intricate and less deterministic than previously assumed. Several puzzling experimental findings have put into question earlier intuitive ideas on: 1) the bottom-up chirality transfer upon amyloidogenic self-assembly, and 2) the structural origins of chiroptical properties of protein aggregates. For example, removal of a single amino acid residue from an amyloidogenic all-L peptide was shown to reverse handedness of fibrils. On the other hand, certain types of amyloid aggregates revealed surprisingly strong VCD spectra with the sign and shape dependent on the conditions of fibrillation. Hence, microscopic and chiroptical studies have highlighted chirality as one more aspect of polymorphism of amyloid fibrils. This brief review is intended to outline the current state of research on amyloid-like fibrils from the perspective of their structural and superstructural chirality and chiroptical properties.

  2. Phospholipids as inhibitors of amyloid fibril formation

    Directory of Open Access Journals (Sweden)

    K. O. Vus

    2016-11-01

    Full Text Available Amyloid fibrils are the protein aggregates, whose formation is involved in the pathogenesis of Alzheimer’s disease, systemic amyloidosis, etc. Since there is no effective ways to treat these diseases, developing the new anti-amyloid drugs is of great importance. In this study a series of phospholipids have been tested for their ability to inhibit lysozyme and insulin amyloid fibril formation at acidic or neutral pH and elevated temperature.  The lag time, elongation rate and fibrillization extent were estimated using Thioflavin T fluorescence assay. It is found that the oxidized and charged phospholipids, included into the liposomes, were the most effective inhibitors of the protein fibrillization. By comparing the magnitude and direction of the lipid effect in different lipid-protein systems it was concluded that the reduction of the amyloid fibril formation is governed by hydrophobic and specific liposome-protein interactions. It is hypothesized that the presence of the surface formed by the lipid polar heads is critical for reducing the protein fibrillization extent.

  3. Modeling generic aspects of ideal fibril formation

    Energy Technology Data Exchange (ETDEWEB)

    Michel, D., E-mail: denis.michel@live.fr [Universite de Rennes1-IRSET, Campus de Beaulieu Bat. 13, 35042 Rennes (France)

    2016-01-21

    Many different proteins self-aggregate into insoluble fibrils growing apically by reversible addition of elementary building blocks. But beyond this common principle, the modalities of fibril formation are very disparate, with various intermediate forms which can be reshuffled by minor modifications of physico-chemical conditions or amino-acid sequences. To bypass this complexity, the multifaceted phenomenon of fibril formation is reduced here to its most elementary principles defined for a linear prototype of fibril. Selected generic features, including nucleation, elongation, and conformational recruitment, are modeled using minimalist hypotheses and tools, by separating equilibrium from kinetic aspects and in vitro from in vivo conditions. These reductionist approaches allow to bring out known and new rudiments, including the kinetic and equilibrium effects of nucleation, the dual influence of elongation on nucleation, the kinetic limitations on nucleation and fibril numbers, and the accumulation of complexes in vivo by rescue from degradation. Overlooked aspects of these processes are also pointed: the exponential distribution of fibril lengths can be recovered using various models because it is attributable to randomness only. It is also suggested that the same term “critical concentration” is used for different things, involved in either nucleation or elongation.

  4. Die Relation von Medienkultur und sozialer Schicht. - Ergebnisse einer empirisch-quantitativen Fragebogenstudie bei Volksschulkindern und deren Lehrerinnen und Lehrern.

    Directory of Open Access Journals (Sweden)

    Ursula Mutsch

    2009-12-01

    Full Text Available In der vorliegenden Studie wird die Medienkultur von Volksschülerinnen und -schülern, deren Eltern und deren Lehrerinnen und Lehrern mittels einer quantitativen Fragebogenerhebung in Wien verglichen. Die Erhebung wurde im Rahmen eines Forschungsprojekts der Wiener Medienpädagogik (Universität Wien durchgeführt. Ausgangspunkt der Studie sind die Annahmen, dass Medienkultur (1 von geografischen und historischen Determinanten bestimmt und im soziokulturellen Kontext zu betrachten ist und (2 Auswirkungen auf die erfolgreiche Integration von Medienbildung und Media Literacy in Volksschulen hat. Zunächst werden der Kontext der Studie und allgemeine Überlegungen vorgestellt. Dem folgt eine Beschreibung der methodischen Umsetzung der Studie mit anschließender Präsentation und Diskussion ausgewählter Resultate. Die Ergebnisse weisen auf schichtspezifische Unterschiede der Medienkultur zwischen Schülerinnen bzw. Schülern und Lehrkräften hin. This study aims to achieve an understanding how media culture of pupils and teachers meet in Austrian (Viennese primary schools. This investigation is part of a project at the University of Vienna which examines media ecudation and media literacy in primary schools, trying to support their development in classrooms. The thesis is that media culture is (1 determined by sociocultural, geographical and historical factors and (2 has an impact on a successful integration of media education in primary schools. So a first aim is to describe and compare the use and access of media in the home of children, their parents and teachers, applying a quantitative questionnaire. At first the context of the study as well as general and theoretical considerations will be presented, following a description of the methodical approach. Finally selected, important results of the study will be discussed. The results show differences concering media culture and literacy practices because of the social class gap.

  5. Curcumin Protects β-Lactoglobulin Fibril Formation and Fibril-Induced Neurotoxicity in PC12 Cells.

    Directory of Open Access Journals (Sweden)

    Mansooreh Mazaheri

    Full Text Available In this study the β-lactoglobulin fibrillation, in the presence or absence of lead ions, aflatoxin M1 and curcumin, was evaluated using ThT fluorescence, Circular dichroism spectroscopy and atomic force microscopy. To investigate the toxicity of the different form of β-Lg fibrils, in the presence or absence of above toxins and curcumin, we monitored changes in the level of reactive oxygen species and morphology of the differentiated neuron-like PC12 cells. The cell viability, cell body area, average neurite length, neurite width, number of primary neurites, percent of bipolar cells and node/primary neurite ratios were used to assess the growth and complexity of PC12 cells exposed to different form of β-Lg fibrils. Incubation of β-Lg with curcumin resulted in a significant decrease in ROS levels even in the presence of lead ions and aflatoxin M1. The β-Lg fibrils formed in the presence of lead ions and aflatoxin M1 attenuated the growth and complexity of PC12 cells compared with other form of β-Lg fibrils. However, the adverse effects of these toxins and protein fibrils were negated in the presence of curcumin. Furthermore, the antioxidant and inhibitory effects of curcumin protected PC12 cells against fibril neurotoxicity and enhanced their survival. Thus, curcumin may provide a protective effect toward β-Lg, and perhaps other protein, fibrils mediated neurotoxicity.

  6. Effect of age on stroke prevention therapy in patients with atrial fibrillation: the atrial fibrillation investigators

    DEFF Research Database (Denmark)

    van Walraven, Carl; Hart, Robert G; Connolly, Stuart

    2009-01-01

    on the relative efficacy of oral anticoagulants (OAC) and antiplatelet (AP) therapy (including acetylsalicylic acid and triflusal) on ischemic stroke, serious bleeding, and vascular events in patients with atrial fibrillation. METHODS: This is an analysis of the Atrial Fibrillation Investigators database, which...

  7. Integration

    DEFF Research Database (Denmark)

    Emerek, Ruth

    2004-01-01

    Bidraget diskuterer de forskellige intergrationsopfattelse i Danmark - og hvad der kan forstås ved vellykket integration......Bidraget diskuterer de forskellige intergrationsopfattelse i Danmark - og hvad der kan forstås ved vellykket integration...

  8. RR-Interval variance of electrocardiogram for atrial fibrillation detection

    Science.gov (United States)

    Nuryani, N.; Solikhah, M.; Nugoho, A. S.; Afdala, A.; Anzihory, E.

    2016-11-01

    Atrial fibrillation is a serious heart problem originated from the upper chamber of the heart. The common indication of atrial fibrillation is irregularity of R peak-to-R-peak time interval, which is shortly called RR interval. The irregularity could be represented using variance or spread of RR interval. This article presents a system to detect atrial fibrillation using variances. Using clinical data of patients with atrial fibrillation attack, it is shown that the variance of electrocardiographic RR interval are higher during atrial fibrillation, compared to the normal one. Utilizing a simple detection technique and variances of RR intervals, we find a good performance of atrial fibrillation detection.

  9. Ergebnisse einer neuen Technik der Meatusplastik im Rahmen der geschlechtsangleichenden Operation von Mann zu Frau

    Directory of Open Access Journals (Sweden)

    Rossi Neto R

    2011-01-01

    Full Text Available In unserer Klinik stellt sich die Meatusstenose als die häufigste Komplikation nach einer geschlechtsangleichenden Operation mit ca. 40 % betroffenen Patientinnen dar, gefolgt von lokalen Wundheilungsstörungen (26 % und Verengung des Introitus vaginalis mit 12 %. Die Hauptkomplikationen werden bei der zweiten Sitzung mit kleinen ästhetischen Korrekturen beseitigt. Trotz einer zweiten Korrektur besteht jedoch immer noch das Risiko (15–20 % der Entstehung einer Striktur der Anastomose. Im Rahmen der Neo-Urethrokutaneostomie besteht grundsätzlich das Problem, dass eine zirkuläre kutane Anastomose im Verlauf zur narbigen Verengung neigt. Um das Stenoserisiko zu reduzieren, ist eine neue Technik der Neo- Urethrokutaneostomie entwickelt und der Verlauf der Patientinnen im Vergleich zur konventionellen Methode verglichen worden. Insgesamt wurden 45 Patientinnen mit dieser Methode operiert und prospektiv analysiert: Gruppe A mit 23 Patientinnen, die eine konventionelle Neo-Urethrokutaneostomie mit Absetzung der Harnröhren auf Hautniveau erhielten, und Gruppe B mit 22 Patientinnen, wobei hier die Harnröhre ca. 1,0–1,5 cm oberhalb des Hautniveaus abgesetzt und eine lange Eversion der Schleimhaut durchgeführt wurde. Insgesamt wurde eine Nachbeobachtung der postoperativen Ergebnisse über 7 Monate durchgeführt, wobei das besondere Augenmerk auf das Maß der subvesikalen Obstruktion gelegt wurde. In Gruppe A wurden bei 19 Patientinnen (82,6 % obstruktive Miktionsbeschwerden aufgrund progressiver Meatusstenosen festgestellt. Insgesamt 14 (61 % von 23 Patientinnen konnten nach 7 Monaten ohne eine zweite Korrektur normal miktionieren. In Gruppe B hingegen berichteten nur 3 (13,6 % Patientinnen über obstruktive Miktionsbeschwerden. Bei 4 Patientinnen (18 % wurde der Dauerkatheter aufgrund einer Durchblutungsstörung des Meatus 3 Tage länger belassen, bei 3 Patientinnen war zur Verbesserung der Wundheilung eine Abtragung von Nekrosen am Harnr

  10. Raumplanerische Ansätze zur Ermittlung einer bedarfsgerechten rettungsdienstlichen Infrastruktur

    Science.gov (United States)

    Behrendt, Holger; Schmiedel, Reinhard

    Die Planung einer bedarfsgerechten rettungsdienstlichen Infrastruktur erfolgt sowohl bei der Festlegung regionaler Zuständigkeitsgebiete von Leitstellen als auch bei der Standortplanung von Rettungswachen/Notarztstandorten nach raumplanerischen Ansätzen. Während bei der Planung der Leitstellenbereiche die Regionalisierung nach siedlungsstrukturellen Gesichtspunkten im Vordergrund steht, ist bei der Standortplanung die flächendeckende Versorgung über eine Mindestzahl an Rettungswachen zu lösen. Beiden Ansätzen ist gemeinsam, daß das Optimierungspotential mit der Größe des Planungsraumes zunimmt, weshalb nach Möglichkeit hier Landesplanungen anzustreben sind.

  11. [Cardiodoron® bei Patienten mit Schlafstörungen - Ergebnisse einer prospektiven Beobachtungsstudie].

    Science.gov (United States)

    Rother, Claudia; Schnelle, Martin

    2017-01-01

    Hintergrund: Schlafstörungen gehören zu den häufigsten gesundheitlichen Problemen der heutigen Zeit. Stress und die dadurch bedingte innere Anspannung sowie eine unrhythmische Lebensführung z.B. durch Schichtarbeit sind bekannte auslösende Faktoren. Weniger bekannt ist, dass auch funktionelle Herz-Kreislauf-Beschwerden zu Störungen des Schlafs führen können und dass deren Behandlung zu einer Verbesserung der Schlafqualität beiträgt. Ganzheitlich betrachtet geht es daher um die Wiederherstellung einer gesunden Rhythmik, insbesondere des Herz-/Atem- sowie des Schlaf-Wach-Rhythmus, die Cardiodoron®, eine Heilpflanzenkomposition aus Primula veris, Hyoscyamus niger und Onopordum acanthium, unterstützt. Patienten und Methoden: Mittels einer prospektiven, multizentrischen Beobachtungsstudie sollte ermittelt werden, wie sich funktionelle Herz-Kreislauf-Beschwerden und/oder Schlafstörungen unter der Behandlung mit Cardiodoron® (Dilution) über 3-6 Monate entwickeln. Im Zeitraum von September 2009 bis März 2012 dokumentierten 92 Ärzte 501 Patienten, von denen 380 über Schlafstörungen klagten und deren Daten in dieser Publikation näher betrachtet werden. Nach einer Aufnahmeuntersuchung erfolgte nach 90 Tagen eine Abschlussuntersuchung und bei Fortführung der Therapie nach nochmals 90 Tagen eine Follow-up-Untersuchung. Neben 30 ärztlicherseits bewerteten Symptomen beurteilten die Patienten ihr Befinden mittels Pittsburgh Sleep Quality Index (PSQI) nach Buysse und der Beschwerden-Liste nach von Zerssen (B-L und B-L'). Ergebnisse: Unter der Cardiodoron®-Therapie gingen bei guter Verträglichkeit sowohl die Ausprägung der Schlafstörungen (um 65% von 2,0 auf 0,7 Punkte) als auch die erfassten 30 Symptome (um 59% von 24,3 auf 9,9 Punkte) deutlich zurück (p mit Schlafstörungen (mit oder ohne funktionelle Herz-Kreislauf-Beschwerden) kann die Ausprägung der Beschwerden mit Cardiodoron® deutlich gesenkt werden. Cardiodoron® ist gut verträglich. © 2016 S

  12. Über den Nachrichtenwert von Friedensjournalismus - Ergebnisse einer experimentellen Studie

    Directory of Open Access Journals (Sweden)

    Monika Spohrs

    2006-04-01

    Full Text Available Laut Nachrichtenwertforschung hängt die Publikations- und Lesenswürdigkeit von Nachrichtentexten von den Nachrichtenfaktoren der zu publizierenden Ereignisse ab. Als anerkannte Nachrichtenfaktoren gelten beispielsweise Negativität, Vereinfachung und Personifizierung. Friedensjournalistische Arbeiten weichen von diesen Kriterien oft ab, indem sie versuchen, die berichteten Ereignisse in ihrer Komplexität darzustellen, den Fokus nicht auf negative Ereignisse zu legen und auch strukturellen Themen Raum zu geben. Aber sind sie deshalb weniger publikationswürdig? Der folgende Artikel zeigt anhand einer experimentellen Studie, welche Akzeptanz Friedensjournalismus beim Leser finden kann, auch wenn dies teilweise den Theorien der Nachrichtenwertforschung widerspricht. Des weiteren wird gezeigt, wie sich konstruktive Berichterstattung auf die mentalen Modelle der Rezipienten auswirkt und in welchem Zusammenhang diese beiden Ergebnisse miteinander stehen. In der vorliegenden Studie wurden einer für die Leserschaft der deutschen Qualitätspresse hinsichtlich Alter und Bildungsgrad repräsentativen Stichprobe von n = 128 Versuchspersonen Zeitungsartikel zu drei verschiedenen Ereignissen im Konfliktfeld des ehemaligen Jugoslawien dargeboten. Zu jedem Ereignis wurden vier verschiedene Textvarianten verwendet: eine gemäßigt eskalationsorientierte Originalfassung aus einer deutschen Qualitätszeitung (Die Welt, Frankfurter Allgemeine Zeitung, Süddeutsche Zeitung und drei modifizierte Versionen dieser Artikel, (a mit gemäßigt deeskalations-orientiertem Framing, (b mit stark deeskalationsorientiertem Framing und (c mit einer Verschärfung der Eskalationsorientierung der dargestellten Konflikte. Die Aufgabe der Vpn bestand darin, zu jedem der drei Ereignisse eine Textvariante zu lesen und danach in eigenen Worten schriftlich wiederzugeben und anschließend einen Fragebogen zu Akzeptanz, Glaubwürdigkeit, Ausgewogenheit, Neuigkeitsgehalt, Bewertung und

  13. Eine nicht schreibende Welt : François Truffauts "Fahrenheit 451" aus einer medienfixierten Perspektive

    OpenAIRE

    2013-01-01

    "Writing Worlds" – ich möchte den Titel der Jahrestagung der Gesellschaft für Fantastikforschung 2013 absichtlich anders verstehen als die naheliegende Bedeutung und ihn mit "schreibende Welten" übersetzen, um mich so einer nicht schreibenden Welt zuwenden zu können: François Truffauts "Fahrenheit 451". In seiner Verfilmung von Ray Bradburys Roman verabsolutiert Truffaut die Quintessenz der Vorlage und präsentiert dem Rezipienten eine Welt, in der nicht nur bestimmte Bücher dem Zensus zum Opf...

  14. Mechanical deformation mechanisms and properties of amyloid fibrils.

    Science.gov (United States)

    Choi, Bumjoon; Yoon, Gwonchan; Lee, Sang Woo; Eom, Kilho

    2015-01-14

    Amyloid fibrils have recently received attention due to their remarkable mechanical properties, which are highly correlated with their biological functions. We have studied the mechanical deformation mechanisms and properties of amyloid fibrils as a function of their length scales by using atomistic simulations. It is shown that the length of amyloid fibrils plays a role in their deformation and fracture mechanisms in such a way that the competition between shear and bending deformations is highly dependent on the fibril length, and that as the fibril length increases, so does the bending strength of the fibril while its shear strength decreases. The dependence of rupture force for amyloid fibrils on their length is elucidated using the Bell model, which suggests that the rupture force of the fibril is determined from the hydrogen bond rupture mechanism that critically depends on the fibril length. We have measured the toughness of amyloid fibrils, which is shown to depend on the fibril length. In particular, the toughness of the fibril with its length of ∼3 nm is estimated to be ∼30 kcal mol(-1) nm(-3), comparable to that of a spider silk crystal with its length of ∼2 nm. Moreover, we have shown the important effect of the pulling rate on the mechanical deformation mechanisms and properties of amyloid fibril. It is found that as the pulling rate increases, so does the contribution of the shear effect to the elastic deformation of the amyloid fibril with its length of deformation mechanism of the amyloid fibril with its length of >15 nm is almost independent of the pulling rate. Our study sheds light on the role of the length scale of amyloid fibrils and the pulling rate in their mechanical behaviors and properties, which may provide insights into how the excellent mechanical properties of protein fibrils can be determined.

  15. Compressive deformation of ultralong amyloid fibrils

    Science.gov (United States)

    Paparcone, Raffaella; Cranford, Steven; Buehler, Markus J.

    2010-12-01

    Involved in various neurodegenerative diseases, amyloid fibrils and plaques feature a hierarchical structure, ranging from the atomistic to the micrometer scale. At the atomistic level, a dense and organized hydrogen bond network is resembled in a beta-sheet rich secondary structure, which drives a remarkable stiffness in the range of 10-20GPa, larger than many other biological nanofibrils, a result confirmed by both experiment and theory. However, the understanding of how these exceptional mechanical properties transfer from the atomistic to the nanoscale remains unknown. Here we report a multiscale analysis that, from the atomistic-level structure of a single fibril, extends to the mesoscale level, reaching size scales of hundreds of nanometers. We use parameters directly derived from full atomistic simulations of A β (1-40) amyloid fibrils to parameterize a mesoscopic coarse-grained model, which is used to reproduce the elastic properties of amyloid fibrils. We then apply our mesoscopic model in an analysis of the buckling behavior of amyloid fibrils with different lengths and report a comparison with predictions from continuum beam theory. An important implication of our results is a severe reduction of the effective modulus due to buckling, an effect that could be important to interpret experimental results of ultra-long amyloid fibrils. Our model represents a powerful tool to mechanically characterize molecular structures on the order of hundreds of nanometers to micrometers on the basis of the underlying atomistic behavior. The work provides insight into structural and mechanical properties of amyloid fibrils and may enable further analysis of larger-scale assemblies such as amyloidogenic bundles or plaques as found in disease states.

  16. GENETIC PREDICTORS OF ATRIAL FIBRILLATION

    Directory of Open Access Journals (Sweden)

    A. V. Kuskaeva

    2016-01-01

    Full Text Available Atrial fibrillation (AF is the most common heart rhythm disturbance. It is believed that the primary form of AF is genetically determined in most cases, but the genetic component cannot be excluded in the secondary form of AF. AF is a heterogeneous disease and many authors proved its relationship with other genetic heart disease. In most cases, certain combinations of polymorphisms of different genes promote the development of AF. The study of genes of renin-angiotensin-aldosterone system (RAAS is especially important, because the role of this system in AF pathogenesis is currently studding most intensively. These studies are of great practical interest, as associative effect of angiotensin-converting enzyme inhibitors and angiotensin II receptor antagonists in the prevention of AF is revealed. RAAS blockers are able not only to reduce the risk of new-onset AF in hypertensive and normotensive patients but also prevent recurrence of AF. Furthermore, experimental studies showed that RAAS blockers prevent not only the remodeling of the left ventricle, and also the left atrium, pointing to the pathogenesis of AF. So, screening for susceptibility genes and the study of their polymorphism is currently an important focus in the study of AF.

  17. [Integrity].

    Science.gov (United States)

    Gómez Rodríguez, Rafael Ángel

    2014-01-01

    To say that someone possesses integrity is to claim that that person is almost predictable about responses to specific situations, that he or she can prudentially judge and to act correctly. There is a closed interrelationship between integrity and autonomy, and the autonomy rests on the deeper moral claim of all humans to integrity of the person. Integrity has two senses of significance for medical ethic: one sense refers to the integrity of the person in the bodily, psychosocial and intellectual elements; and in the second sense, the integrity is the virtue. Another facet of integrity of the person is la integrity of values we cherish and espouse. The physician must be a person of integrity if the integrity of the patient is to be safeguarded. The autonomy has reduced the violations in the past, but the character and virtues of the physician are the ultimate safeguard of autonomy of patient. A field very important in medicine is the scientific research. It is the character of the investigator that determines the moral quality of research. The problem arises when legitimate self-interests are replaced by selfish, particularly when human subjects are involved. The final safeguard of moral quality of research is the character and conscience of the investigator. Teaching must be relevant in the scientific field, but the most effective way to teach virtue ethics is through the example of the a respected scientist.

  18. Amyloid-like fibril elongation follows michaelis-menten kinetics

    National Research Council Canada - National Science Library

    Milto, Katazyna; Botyriute, Akvile; Smirnovas, Vytautas

    2013-01-01

    ... are. We obtained experimental data on insulin amyloid-like fibril elongation at the conditions where other processes which may impact kinetics of fibril formation are minor and fitted it using Michaelis-Menten equation...

  19. Risk of atrial fibrillation and stroke in rheumatoid arthritis

    DEFF Research Database (Denmark)

    Lindhardsen, Jesper; Ahlehoff, Ole; Gislason, Gunnar Hilmar;

    2012-01-01

    To determine if patients with rheumatoid arthritis have increased risk of atrial fibrillation and stroke.......To determine if patients with rheumatoid arthritis have increased risk of atrial fibrillation and stroke....

  20. Management and prognosis of atrial fibrillation in the diabetic patient

    DEFF Research Database (Denmark)

    Pallisgaard, Jannik Langtved; Lindhardt, Tommi Bo; Olesen, Jonas Bjerring

    2015-01-01

    The global burden of atrial fibrillation and diabetes mellitus (diabetes) is considerable, and prevalence rates are increasing. Diabetes is associated with an increased risk of developing atrial fibrillation; however, diabetes also influences the management and prognosis of atrial fibrillation. I...... and outcomes of heart failure and the success rates of both ablation and cardioversion in atrial fibrillation patients with diabetes. Finally, this article describes the association of HbA1c levels with the management and prognosis of atrial fibrillation patients.......The global burden of atrial fibrillation and diabetes mellitus (diabetes) is considerable, and prevalence rates are increasing. Diabetes is associated with an increased risk of developing atrial fibrillation; however, diabetes also influences the management and prognosis of atrial fibrillation...

  1. Surgical Treatment of Atrial Fibrillation: A Review

    Directory of Open Access Journals (Sweden)

    Nadine Hiari

    2011-01-01

    Full Text Available Atrial fibrillation is the most commonly sustained arrhythmia in man. While it affects millions of patients worldwide, its incidence will markedly increase with an aging population. Primary goals of AF therapy are to (1 reduce embolic complications, particularly stroke, (2 alleviate symptoms, and (3 prevent long-term heart remodelling. These have been proven to be a challenge as there are major limitations in our knowledge of the pathological and electrophysiological mechanisms underlying AF. Although advances continue to be made in the medical management of this condition, pharmacotherapy is often unsuccessful. Because of the high recurrence rate of AF despite antiarrhythmic drug therapy for maintenance of sinus rhythm and the adverse effects of these drugs, there has been growing interest in nonpharmacological strategies. Surgery for treatment of AF has been around for some time. The Cox-Maze procedure is the gold standard for the surgical treatment of atrial fibrillation and has more than 90% success in eliminating atrial fibrillation. Although the cut and sew maze is very effective, it has been superseded by newer operations that rely on alternate energy sources to create lines of conduction block. In addition, the evolution of improved ablation technology and instrumentation has facilitated the development of minimally invasive approaches. In this paper, the rationale for surgical ablation for atrial fibrillation and the different surgical techniques that were developed will be explored. In addition, it will detail the new approaches to surgical ablation of atrial fibrillation that employ alternate energy sources.

  2. A resorcinarene for inhibition of Aβ fibrillation.

    Science.gov (United States)

    Han, Xu; Park, Jiyong; Wu, Wei; Malagon, Andres; Wang, Lingyu; Vargas, Edgar; Wikramanayake, Athula; Houk, K N; Leblanc, Roger M

    2017-03-01

    Amyloid-β peptides (Aβ) fibrillation is the hallmark of Alzheimer's disease (AD). However, it has been challenging to discover potent agents in order to inhibit Aβ fibrillation. Herein, we demonstrated the effect of resorcinarene on inhibiting Aβ fibrillation in vitro via experimental and computational methods. Aβ were incubated with different concentrations of resorcinarene so as to monitor the kinetics by using thioflavin T binding assay. The results, which were further confirmed by far-UV CD spectroscopy and atomic force microscopy, strongly indicated that the higher concentration of resorcinarene, the more effective the inhibition of Aβ fibrillation. A cytotoxicity study showed that when sea urchin embryos were exposed to the resorcinarene, the majority survived due to the resorcinarene low toxicity. In addition, when the resorcinarene was added, the formation of toxic Aβ 42 species was delayed. Computational studies of Aβ fibrillation, including docking simulations and MD simulations, illustrated that the interaction between inhibitor resorcinarene and Aβ is driven by the non-polar interactions. These studies display a novel strategy for the exploration of promising antiamyloiddogenic agents for AD treatments.

  3. Synthese von analogen Filtern auf einer rekonfigurierbaren Hardware-Architektur mittels eines Genetischen Algorithmus

    Directory of Open Access Journals (Sweden)

    S. Trendelenburg

    2008-05-01

    Full Text Available Rekonfigurierbare Analog-Arrays (FPAAs sind der Versuch, die Vorteile der aus der digitalen Welt bekannten FPGAs (Flexibilität, Entwurfsgeschwindigkeit auch für analoge Anwendungen verfügbar zu machen. Aufgrund der Vielfalt der analogen Schaltungstechnik ist die Abbildung von vorgegebenen Schaltungskonzepten auf eine FPAA-Architektur nicht immer einfach lösbar.

    Diese Arbeit stellt einen neuen Ansatz für die Synthese von Filtern auf einer FPAA-Architektur für zeitkontinuierliche Analogfilter mittels eines Genetischen Algorithmus (GA vor. Anhand eines Matlab-Modells des FPAA, das eine gute übereinstimmung mit Simulationen des FPAA auf Transistorebene aufweist, wurde gezeigt, dass eine große Vielzahl verschiedener Filterstrukturen auf dieser Architektur dargestellt werden kann. Daraufhin wurde ein Genetischer Algorithmus entwickelt, der es erlaubt, aus einer gegebenen Filterspezifikation Konfigurationsdatensätze zu synthetisieren, die den gewünschten Filter auf die FPAA-Architektur abbilden.

  4. [COPD und Klangtherapie: Pilotstudie zur Wirksamkeit einer Behandlung mit Körpertambura bei COPD-Patienten].

    Science.gov (United States)

    Hartwig, Bernhard; Schmidt, Stefan; Hartwig, Isabella

    2016-01-01

    Hintergrund: Erkrankungen der Atemorgane treten mit steigendem Alter öfter auf, nehmen weltweit zu und sind häufige Ursachen für Morbidität und Mortalität. In dieser Pilotstudie wurde der Frage nachgegangen, ob eine einmalige 10-minütige Behandlung mit einer Körpertambura eine signifikante und effektive Verbesserung der Lungenfunktion von Patienten mit chronisch-obstruktiver Lungenerkrankung (COPD; GOLD-Stadium A oder B) erbringen kann. Patienten und Methoden: 54 Probanden konnten je zur Hälfte in eine Behandlungsgruppe (Körpertambura) und eine aktive Kontrollgruppe (Atemtherapie) randomisiert werden. Eine Bestimmung der Lungenfunktionsmessparameter «Einsekundenkapazität» (FEV1) und «inspiratorische Vitalkapazität» (IVC) zu den Zeitpunkten T1 (Baseline), T2 (direkt nach Behandlung) und als Follow-up etwa 3 Wochen nach T1 (T3). Ergebnisse: Die Behandlungsgruppe zeigte sich der Kontrollgruppe in beiden Werten signifikant überlegen. Die Zeit-×-Gruppe-Interaktion (Varianzanalyse) ergab p = 0,001 (FEV1) bzw. p = 0,04 (IVC). Die Behandlungsgruppe zeigte bei beiden Werten eine Verbesserung von klinischer Relevanz. Schlussfolgerung: Diese Ergebnisse zeigen, dass die Klangbehandlung mittels einer Körpertambura - neben den schulmedizinischen, leitliniengerechten Therapien - eine zusätzliche, nebenwirkungsarme, aber durchaus klinisch wirksame Option für die Behandlung von COPD-Patienten darstellen kann, um deren Lebensqualität zu stabilisieren und zu verbessern. © 2016 S. Karger GmbH, Freiburg.

  5. Permanente sakrale Neuromodulation mittels InterStim®: Ergebnisse einer Anwendungsbefragung zu aktuellen technischen Entwicklungen

    Directory of Open Access Journals (Sweden)

    Sievert KD

    2007-01-01

    Full Text Available In den vergangenen über 20 Jahren wurde die sakrale Neuromodulation als klinische Therapie etabliert. Die anfängliche Indikation wurde ständig erweitert und umfaßt heute verschiedene Formen der Blasen- und Stuhlentleerungsstörung sowie eingeschränkt die Schmerztherapie im kleinen Becken. Fortwährend wurde die Technik der Implantation verbessert und die zur Verfügung stehende Hardware verkleinert. Als Resultat der konsequenten Weiterentwicklung wurde im letzten Jahr der miniaturisierte InterStim® II vorgestellt und dessen klinischer Einsatz durch versierte Operateure der unterschiedlichsten Disziplinen mittels einer internetbasierten Befragung beurteilt. Durch die Verwendung des InterStim® II werden im Vergleich zum InterStim® die operative Invasivität mit der Operationszeit und daraus resultierend der postoperative Schmerz gesenkt. Die neue Fernbedienung läßt einen weiteren Anstieg der Akzeptanz erwarten, da durch das Display der Fernbedienung der Patient die Einstellungen kontrollieren kann. Die weitere Miniaturisierung mit gleichzeitig erweiterter Programmierbarkeit des Implantates, der direkten Verbindung von Elektrode und Impulsgeber mit einer einzelnen Schraube verbessert die Option der Neuromodulation weiter. Die Entwicklungen unterstützen den minimal-invasiven Aspekt der InterStim®-Therapie, wodurch die Möglichkeit der ambulanten Therapieoption gegeben sein könnte. Es bleibt abzuwarten, ob die Therapie der Neuromodulation durch die erweiterten Programmiermöglichkeiten für den einzelnen Patienten in Zukunft noch individueller im chronischen Einsatz optimiert werden kann.

  6. "Doing pupil" nach Schulschluss – Videografie an einer Kinderuniversität

    Directory of Open Access Journals (Sweden)

    Alexandra König

    2015-03-01

    Full Text Available Auf der Basis einer Videografie an einer Kinderuniversität wird in dem vorliegenden Beitrag die Frage verfolgt, wie an einem außerschulischen Lernort generationale Ordnung hergestellt wird und welche Gestalt diese annimmt. Als heuristischer Rahmen dient das Modell der "Sozialisation als generationales Ordnen" (BÜHLER-NIEDERBERGER 2011; BÜHLER-NIEDERBERGER & TÜRKYILMAZ 2014. Die Analyse der ersten Sitzungen von zwei kontrastiven Kursen an der Kinder- und Jugenduniversität zeigt erstens, wie Kinder struktursensitiv Regeln in dem unbekannten Kontext erspüren, erarbeiten und modifizieren, wie sie KomplizInnen in der Herstellung generationaler Ordnung sind. Zweitens wird die Dominanz der schulischen Ordnung und des SchülerInnenstatus für Kindheit deutlich. Die Kinder stellen "Schule" her – paradoxerweise auch in einem außerschulischen Kontext. Drittens wird im kontrastiven Vergleich der untersuchten Kurse eine Varianz dieser Ordnungen – in Bezug auf die Form des Wissens und Adressierung der Kinder – herausgearbeitet, die allerdings die Dominanz der schulischen Ordnung nicht bricht. URN: http://nbn-resolving.de/urn:nbn:de:0114-fqs150263

  7. Biogas generation and use at a dairy-cattle plant; Biogaserzeugung und -verwertung auf einer Milchviehanlage

    Energy Technology Data Exchange (ETDEWEB)

    Jaekel, K. [Saechsische Landesanstalt fuer Landwirtschaft, Leipzig (Germany); Eichert, H. [Hochschule fuer Technik und Wirtschaft, Zwickau (Germany); Ackermann, J. [Hochschule fuer Technik und Wirtschaft, Zwickau (Germany)

    1996-12-31

    At a dairy-cattle plant of the Lungwitztal agrarian co-operative society in Saxony (approximately 1000 head of cattle), a biogas-fuelled cogeneration plant with an electric power output of 220 kilowatts and a thermal power output of 350 kilowatts went operational in 1995. The article reports the operating experience so far gathered, first data concerning the energy budget (the plant`s own power demand, power fed into the grid, use potential) as well as first results regarding the influence of the mixed substrate used (cattle manure with irregular admixtures of chicken dung, molasses, fatty water) on biogas production. (orig.) [Deutsch] Auf einer Milchviehanlage der Agrargenossenschaft Lungwitztal e.g. in Sachsen (rund 1000 GVE) wurde 1995 ein Biogas-BHKW mit einer Leistung von 220 kW elektrisch und 350 kW thermisch in Betrieb genommen. Es werden die bisherigen Betriebserfahrungen, erste Ergebnisse zur Energiebilanz (Eigenbedarf, Netzeinspeisung, Nutzungspotential) sowie zum Einfluss des eingesetzten Mischsubstrates (Rinderguelle mit unregelmaessigen Zuschlaegen von Huehnerkot, Melasse, Fettwasser) auf die Biogasproduktion vorgestellt. (orig.)

  8. Squamous cell carcinoma originating from a thyroglossus duct cyst; Plattenepithelkarzinom der Schilddruese ausgehend von einer Ductus thyreoglossus Zyste

    Energy Technology Data Exchange (ETDEWEB)

    Kresnik, E. [Nuklearmedizinische Abt., LKH Klagenfurt (Austria); Gallowitsch, H.J. [Nuklearmedizinische Abt., LKH Klagenfurt (Austria); Ploeb, J. [Nuklearmedizinische Abt., LKH Klagenfurt (Austria); Gomez, I. [Nuklearmedizinische Abt., LKH Klagenfurt (Austria); Mikosch, P. [Nuklearmedizinische Abt., LKH Klagenfurt (Austria); Dinges, H.P. [Pathologisches Inst., LKH Klagenfurt (Austria); Lind, P. [Nuklearmedizinische Abt., LKH Klagenfurt (Austria)

    1995-04-01

    A 73 y old female was found to suffer from a squamous cell carcinoma with a focal thymus-like differentiation in a thyroglossal duct cyst. A neoplasma of this type in a goitre with Graves` disease is extremely rare. Sonographic, radiological, scintigraphic and microscopic findings are discussed. (orig.) [Deutsch] Es wird ueber eine 73jaehrige Patientin mit dem sehr seltenen Fall eines Karzinoms berichtet, das sich in einer Ductus thyreoglossus-Zyste innerhalb einer Struma diffusa et nodosa entwickelt hatte. Zusaetzlich bestand eine Immunthyreopathie Typ Basedow. Sonographische, roentgenologische, szintigraphische und histologische Befunde werden vorgestellt. (orig.)

  9. Mitochondrialer Sensorineuraler Hörverlust: Beiderseitige Cochlear Implantation bei einer 46-jährigen Patientin mit MELAS-Syndrom

    OpenAIRE

    Ehrt, K; Just, T; Pau, HW; R. Dahl

    2014-01-01

    Beim MELAS-Syndrom handelt es sich um eine degenerative ZNS-Erkrankung, die bei etwa 50% der Patienten mit einer Hörstörung einhergehen kann. Neben einer mitochondrialen Enzephalopathie leiden die Patienten u.a. an Laktatazidose, Myopathie und Schlaganfall-ähnlichen Episoden.Vermutet wird, dass metabolische Störungen der Stria vascularis und der äußeren Haarzellen die Fehlfunktion der Cochlea hervorruft.Vorgestellt wird eine 46-jährige Patientin mit einem nachgewiesenen MELAS-Syndrom (mitocho...

  10. Contribution of Long Fibrils and Peptides to Surface and Foaming Behavior of Soy Protein Fibril System.

    Science.gov (United States)

    Wan, Zhili; Yang, Xiaoquan; Sagis, Leonard M C

    2016-08-16

    When soy glycinin (11S) is heated for a prolonged time at pH 2 (20 h at 85 °C), a mixture is formed consisting of long semiflexible 11S fibrils and small peptides. The surface and foaming properties of this mixture were investigated at different pHs, and compared to the behavior of pure fibrils and pure peptides, to determine the individual contributions of these two factions to the behavior of the mixture. The adsorption of these three systems at air-water interfaces and the resulting surface rheological properties were studied by combining drop shape analysis tensiometry, ellipsometry, and surface large amplitude oscillatory dilatational (LAOD) rheology. Lissajous plots of surface pressure versus deformation were used to analyze the surface rheological response in terms of interfacial microstructure. Our results show that the adsorption kinetics, dilatational rheological properties, and the foaming behavior of the mixture were mainly dominated by the small peptides in the fibril system. Compared to pH 2, the fibril mixture at pH 5 and 7 provides much better foam stability and appears to be a very promising protein material to make stable foams, even at low protein concentration (0.1 wt %). The presence of fibril clusters and peptide aggregates at pH 5 and 7 contributed to foam stability of the mixture. In contrast, pure fibril formed an interface with a highly pH-responsive adsorption and rheological behavior, and the foamability and foam stability of the pure fibrils were very poor.

  11. Fracture of Protein Fibrils As Induced by Elongational Flow

    NARCIS (Netherlands)

    Kroes-Nijboer, A.; Venema, P.; Baptist, H.G.M.; Linden, van der E.

    2010-01-01

    The length distribution of whey protein fibrils is important for application purposes. However, it is hard to influence the length distribution of whey protein fibrils during production. One way of influencing the length distribution of the mature fibrils is exposing them to an external field, like

  12. Artificial atrial fibrillation in the dog. An artifact?

    NARCIS (Netherlands)

    Strackee, J.; Hoelen, A.J.; Zimmerman, A.N.E.; Meijler, F.L.

    1971-01-01

    R-R interval sequences during artificial atrial fibrillation in dogs were studied in the same way as in patients in a previous study and compared with results obtained in dogs with spontaneous atrial fibrillation. Artificial atrial fibrillation was effected by right atrial stimulation in three close

  13. Autonomic and surgical substrate modulation of atrial fibrillation

    NARCIS (Netherlands)

    Krul, S.P.J.

    2016-01-01

    This thesis focuses on the effects of fibrosis and the autonomic nervous system on conduction in patients with atrial fibrillation and the surgical ablation of the atria and autonomic nervous system as treatment of atrial fibrillation. Atrial fibrillation is the most common arrhythmia and results fr

  14. Galectin-3 in patients undergoing ablation of atrial fibrillation

    Directory of Open Access Journals (Sweden)

    Nicolas Clementy

    2014-11-01

    Conclusions: Persistent type of atrial fibrillation is an independent predictor of higher Galectin-3 concentration. This biomarker of fibrosis may be implied in the mechanisms of atrial remodeling and maintenance of atrial fibrillation, and thus be helpful for the design of therapeutic strategy in patients with atrial fibrillation.

  15. Universal Behavior in the Mesoscale Properties of Amyloid Fibrils

    Science.gov (United States)

    Assenza, Salvatore; Adamcik, Jozef; Mezzenga, Raffaele; De Los Rios, Paolo

    2014-12-01

    Amyloid fibrils are ubiquitous proteinaceous aggregates occurring in vivo and in vitro, with an invariant structural fingerprint at the molecular length scale. However, interpretation of their mesoscopic architectures is complicated by diverse observable polymorphic states. We here present a constitutive model for amyloid fibrils based on the minimization of the total energy per fibril. The model is benchmarked on real amyloid fibrils studied by atomic force microscopy. We use multistranded β -lactoglobulin amyloid fibrils as a model system exhibiting a rich polymorphism. The constitutive model quantitatively recapitulates the main mesoscopic topological features of amyloid fibrils, that is, the evolution of fibril periodicity as a function of the ionic strength of the solution and of the fibril width. A universal mesoscopic structural signature of the fibrils emerges from this picture, predicting a general, parameter-free law for the periodicity of the fibrils, that depends solely on the number of protofilaments per fibril. These predictions are validated experimentally and conclusively highlight the role of competing electrostatic and elastic contributions as the main players in the establishment of amyloid fibrils structure.

  16. POSTOPERATIVE ATRIAL FIBRILLATION – AN UPDATE

    Directory of Open Access Journals (Sweden)

    Johnson Francis

    2015-12-01

    Full Text Available Atrial fibrillation is the most common perioperative cardiac arrhythmia. Sympathetic overactivity, inflammatory state and oxidative stress are important contributors to the genesis of postoperative atrial fibrillation. Advancing age and mitral valve disease along with left atrial size are important parameters in noted in multivariate prediction model. Genetic predisposition has also been noted. Preventive strategies tried include beta blockers, statins, posterior pericardiotomy, carperitide infusion and thoracic epidural analgesia. Treatment options include rate and rhythm control along with anticoagulation if it persists more than 48 hours with high CHADS2 score. Some of the therapeutic modalities which have been found to be NOT useful in preventing post operative atrial fibrillation are dexamethasone, magnesium infusion and concomitant pulmonary vein isolation.

  17. Antihypertensive treatment and risk of atrial fibrillation

    DEFF Research Database (Denmark)

    Marott, Sarah C W; Nielsen, Sune F; Benn, Marianne

    2014-01-01

    AIMS: To examine the associations between antihypertensive treatment with angiotensin-converting enzyme inhibitors (ACEis) or angiotensin receptor blockers (ARBs), β-blockers, diuretics, or calcium-antagonists, and risk of atrial fibrillation. We examined these associations using the entire Danish...... population from 1995 through 2010. METHODS AND RESULTS: Excluding medication used in atrial fibrillation, we matched individuals on ACEi monotherapy 1:1 with individuals on β-blocker (n = 48 658), diuretic (n = 69 630), calcium-antagonist (n = 57 646), and ARB monotherapy (n = 20 158). Likewise, individuals...... on ARB monotherapy were matched 1:1 with individuals on β-blocker (n = 20 566), diuretic (n = 20 832), calcium-antagonist (n = 20 232), and ACEi monotherapy (n = 20 158). All were free of atrial fibrillation and of predisposing diseases like heart failure, ischaemic heart disease, diabetes mellitus...

  18. Elastic Response of Crimped Collagen Fibrils

    Science.gov (United States)

    Freed, Alan D.; Doehring, Todd C.

    2005-01-01

    A physiologic constitutive expression is presented in algorithmic format for the elastic response of wavy collagen fibrils found in soft connective tissues. The model is based on the observation that crimped fibrils have a three-dimensional structure at the micrometer scale that we approximate as a helical spring. The symmetry of this waveform allows the force/displacement relationship derived from Castigliano's theorem to be solved in closed form. Model predictions are in good agreement with experimental observations for mitral-valve chordae tendineae

  19. Atrial natriuretic peptide in patients with heart failure and chronic atrial fibrillation : Role of duration of at atrial fibrillation

    NARCIS (Netherlands)

    Van Den Berg, MP; Crijns, HJGM; Van Veldhuisen, DJ; Van Gelder, IC; De Kam, PJ; Lie, KI

    1998-01-01

    The purpose of this study was to analyze the determinants of atrial natriuretic peptide level in patients with congestive heart failure and atrial fibrillation. In particular, the duration of atrial fibrillation was analyzed because atrial fibrillation per se might have a specific effect on atrial n

  20. Uniform spatial distribution of collagen fibril radii within tendon implies local activation of pC-collagen at individual fibrils

    Science.gov (United States)

    Rutenberg, Andrew D.; Brown, Aidan I.; Kreplak, Laurent

    2016-08-01

    Collagen fibril cross-sectional radii show no systematic variation between the interior and the periphery of fibril bundles, indicating an effectively constant rate of collagen incorporation into fibrils throughout the bundle. Such spatially homogeneous incorporation constrains the extracellular diffusion of collagen precursors from sources at the bundle boundary to sinks at the growing fibrils. With a coarse-grained diffusion equation we determine stringent bounds, using parameters extracted from published experimental measurements of tendon development. From the lack of new fibril formation after birth, we further require that the concentration of diffusing precursors stays below the critical concentration for fibril nucleation. We find that the combination of the diffusive bound, which requires larger concentrations to ensure homogeneous fibril radii, and lack of nucleation, which requires lower concentrations, is only marginally consistent with fully processed collagen using conservative bounds. More realistic bounds may leave no consistent concentrations. Therefore, we propose that unprocessed pC-collagen diffuses from the bundle periphery followed by local C-proteinase activity and subsequent collagen incorporation at each fibril. We suggest that C-proteinase is localized within bundles, at fibril surfaces, during radial fibrillar growth. The much greater critical concentration of pC-collagen, as compared to fully processed collagen, then provides broad consistency between homogeneous fibril radii and the lack of fibril nucleation during fibril growth.

  1. Stop-and-go kinetics in amyloid fibrillation

    DEFF Research Database (Denmark)

    Ferkinghoff-Borg, Jesper; Fonslet, Jesper; Andersen, Christian Beyschau

    2010-01-01

    in an intermittent fashion, with periods of growth followed by long pauses. The observed exponential distributions of stop and growth times support a Markovian model, in which fibrils shift between the two states with specific rates. Even if the individual rates vary considerably, we observe that the probability......Many human diseases are associated with protein aggregation and fibrillation. We present experiments on in vitro glucagon fibrillation using total internal reflection fluorescence microscopy, providing real-time measurements of single-fibril growth. We find that amyloid fibrils grow...

  2. New risk factors for atrial fibrillation : causes of 'not-so-lone atrial fibrillation'

    NARCIS (Netherlands)

    Schoonderwoerd, Bas A.; Smit, Marcelle D.; Pen, Lucas; Van Gelder, Isabelle C.

    Atrial fibrillation (AF) is a prevalent arrhythmia in patients with cardiovascular disease. The classical risk factors for developing AF include hypertension, valvular disease, (ischaemic) cardiomyopathy, diabetes mellitus, and thyroid disease. In some patients with AF, no underlying

  3. New risk factors for atrial fibrillation : causes of 'not-so-lone atrial fibrillation'

    NARCIS (Netherlands)

    Schoonderwoerd, Bas A.; Smit, Marcelle D.; Pen, Lucas; Van Gelder, Isabelle C.

    2008-01-01

    Atrial fibrillation (AF) is a prevalent arrhythmia in patients with cardiovascular disease. The classical risk factors for developing AF include hypertension, valvular disease, (ischaemic) cardiomyopathy, diabetes mellitus, and thyroid disease. In some patients with AF, no underlying (cardiovascular

  4. Personalized management of atrial fibrillation: Proceedings from the fourth Atrial Fibrillation competence NETwork/European Heart Rhythm Association consensus conference.

    Science.gov (United States)

    Kirchhof, Paulus; Breithardt, Günter; Aliot, Etienne; Al Khatib, Sana; Apostolakis, Stavros; Auricchio, Angelo; Bailleul, Christophe; Bax, Jeroen; Benninger, Gerlinde; Blomstrom-Lundqvist, Carina; Boersma, Lucas; Boriani, Giuseppe; Brandes, Axel; Brown, Helen; Brueckmann, Martina; Calkins, Hugh; Casadei, Barbara; Clemens, Andreas; Crijns, Harry; Derwand, Roland; Dobrev, Dobromir; Ezekowitz, Michael; Fetsch, Thomas; Gerth, Andrea; Gillis, Anne; Gulizia, Michele; Hack, Guido; Haegeli, Laurent; Hatem, Stephane; Häusler, Karl Georg; Heidbüchel, Hein; Hernandez-Brichis, Jessica; Jais, Pierre; Kappenberger, Lukas; Kautzner, Joseph; Kim, Steven; Kuck, Karl-Heinz; Lane, Deirdre; Leute, Angelika; Lewalter, Thorsten; Meyer, Ralf; Mont, Lluis; Moses, Gregory; Mueller, Markus; Münzel, Felix; Näbauer, Michael; Nielsen, Jens Cosedis; Oeff, Michael; Oto, Ali; Pieske, Burkert; Pisters, Ron; Potpara, Tatjana; Rasmussen, Lars; Ravens, Ursula; Reiffel, James; Richard-Lordereau, Isabelle; Schäfer, Herbert; Schotten, Ulrich; Stegink, Wim; Stein, Kenneth; Steinbeck, Gerhard; Szumowski, Lukasz; Tavazzi, Luigi; Themistoclakis, Sakis; Thomitzek, Karen; Van Gelder, Isabelle C; von Stritzky, Berndt; Vincent, Alphons; Werring, David; Willems, Stephan; Lip, Gregory Y H; Camm, A John

    2013-11-01

    The management of atrial fibrillation (AF) has seen marked changes in past years, with the introduction of new oral anticoagulants, new antiarrhythmic drugs, and the emergence of catheter ablation as a common intervention for rhythm control. Furthermore, new technologies enhance our ability to detect AF. Most clinical management decisions in AF patients can be based on validated parameters that encompass type of presentation, clinical factors, electrocardiogram analysis, and cardiac imaging. Despite these advances, patients with AF are still at increased risk for death, stroke, heart failure, and hospitalizations. During the fourth Atrial Fibrillation competence NETwork/European Heart Rhythm Association (AFNET/EHRA) consensus conference, we identified the following opportunities to personalize management of AF in a better manner with a view to improve outcomes by integrating atrial morphology and damage, brain imaging, information on genetic predisposition, systemic or local inflammation, and markers for cardiac strain. Each of these promising avenues requires validation in the context of existing risk factors in patients. More importantly, a new taxonomy of AF may be needed based on the pathophysiological type of AF to allow personalized management of AF to come to full fruition. Continued translational research efforts are needed to personalize management of this prevalent disease in a better manner. All the efforts are expected to improve the management of patients with AF based on personalized therapy.

  5. Evidence of structurally continuous collagen fibrils in tendon

    DEFF Research Database (Denmark)

    Svensson, Rene B; Herchenhan, Andreas; Starborg, Tobias

    2017-01-01

    in this structure-function relationship is the collagen fibril length. During embryogenesis short fibrils are produced but they grow rapidly with maturation. There is some controversy regarding fibril length in adult tendon, with mechanical data generally supporting discontinuity while structural investigations......Tendons transmit muscle-generated force through an extracellular matrix of aligned collagen fibrils. The force applied by the muscle at one end of a microscopic fibril has to be transmitted through the macroscopic length of the tendon by mechanisms that are poorly understood. A key element...... fibrils was confirmed. In light of these results, possible mechanisms that could reconcile the opposing findings on fibril continuity are discussed. STATEMENT OF SIGNIFICANCE: Connective tissues hold all parts of the body together and are mostly constructed from thin threads of the protein collagen...

  6. Amyloid-like fibril elongation follows michaelis-menten kinetics.

    Science.gov (United States)

    Milto, Katazyna; Botyriute, Akvile; Smirnovas, Vytautas

    2013-01-01

    A number of proteins can aggregate into amyloid-like fibrils. It was noted that fibril elongation has similarities to an enzymatic reaction, where monomers or oligomers would play a role of substrate and nuclei/fibrils would play a role of enzyme. The question is how similar these processes really are. We obtained experimental data on insulin amyloid-like fibril elongation at the conditions where other processes which may impact kinetics of fibril formation are minor and fitted it using Michaelis-Menten equation. The correlation of the fit is very good and repeatable. It speaks in favour of enzyme-like model of fibril elongation. In addition, obtained [Formula: see text] and [Formula: see text] values at different conditions may help in better understanding influence of environmental factors on the process of fibril elongation.

  7. Evidence of structurally continuous collagen fibrils in tendon

    DEFF Research Database (Denmark)

    Svensson, Rene B; Herchenhan, Andreas; Starborg, Tobias

    2017-01-01

    fibrils was confirmed. In light of these results, possible mechanisms that could reconcile the opposing findings on fibril continuity are discussed. STATEMENT OF SIGNIFICANCE: Connective tissues hold all parts of the body together and are mostly constructed from thin threads of the protein collagen......Tendons transmit muscle-generated force through an extracellular matrix of aligned collagen fibrils. The force applied by the muscle at one end of a microscopic fibril has to be transmitted through the macroscopic length of the tendon by mechanisms that are poorly understood. A key element...... in this structure-function relationship is the collagen fibril length. During embryogenesis short fibrils are produced but they grow rapidly with maturation. There is some controversy regarding fibril length in adult tendon, with mechanical data generally supporting discontinuity while structural investigations...

  8. AFM study of glucagon fibrillation via oligomeric structures resulting in interwoven fibrils

    Energy Technology Data Exchange (ETDEWEB)

    Dong Mingdong [Interdisciplinary Nanoscience Center (iNANO), University of Aarhus, DK-8000 Aarhus C (Denmark); Hovgaard, Mads Bruun [Interdisciplinary Nanoscience Center (iNANO), University of Aarhus, DK-8000 Aarhus C (Denmark); Xu Sailong [Interdisciplinary Nanoscience Center (iNANO), University of Aarhus, DK-8000 Aarhus C (Denmark); Otzen, Daniel Erik [Interdisciplinary Nanoscience Center (iNANO), University of Aarhus, DK-8000 Aarhus C (Denmark); Besenbacher, Flemming [Interdisciplinary Nanoscience Center (iNANO), University of Aarhus, DK-8000 Aarhus C (Denmark)

    2006-08-28

    Glucagon is a 29-residue amphiphatic hormone involved in the regulation of blood glucose levels in conjunction with insulin. In concentrated aqueous solutions, glucagon spontaneously aggregates to form amyloid fibrils, destroying its biological activity. In this study we utilize the atomic force microscope (AFM) to elucidate the fibrillation mechanism of glucagon at the nanoscale under acidic conditions (pH 2.0) by visualizing the nanostructures of fibrils formed at different stages of the incubation. Hollow disc-shaped oligomers form at an early stage in the process and subsequently rearrange to more solid oligomers. These oligomers co-exist with, and most likely act as precursors for, protofibrils, which subsequently associate to form at least three different classes of higher-order fibrils of different heights. A repeat unit of around 50 nm along the main fibril axis suggests a helical arrangement of interwoven protofibrils. The diversity of oligomeric and fibrillar arrangements formed at pH 2.0 complements previous spectroscopic analyses that revealed that fibrils formed under different conditions can differ substantially in stability and secondary structure.

  9. Hypercoagulability promotes atrial fibrosis and fibrillation

    NARCIS (Netherlands)

    Spronk, Henri M.H.; De Jong, Anne-Margreet; De Boer, Hetty C.; Maas, Alexander; Verheule, Sander; Rienstra, Michiel; Kamphuisen, Pieter W.; Ten Cate, Hugo; Crijns, Harry J.; Van Gelder, Isabelle; Van Zonneveld, Anton Jan; Schotten, Ullrich

    2014-01-01

    Background: It is well known that atrial fibrillation (AF) induces a hypercoagulable state, which significantly increases stroke risk in patients with AF contributing to morbidity and mortality in these patients. Active coagulation factors can also provoke diverse cellular responses through stimulat

  10. Primary care aspects of atrial fibrillation

    NARCIS (Netherlands)

    Meijler, F.L.; Tweel, I. van der

    1985-01-01

    A better understanding of the pathophysiologic mechanisms that determine the random pattem of ventricular rhythm may assist the primary care physician in treating and guiding atrial fibrillation patients. These mechanisms also form the basis for our understanding of drug action and effect on ventric

  11. Spontaneous conversion of first onset atrial fibrillation

    DEFF Research Database (Denmark)

    Lindberg, Søren Østergaard; Hansen, Sidsel; Nielsen, Tonny

    2011-01-01

    Background  We studied all patients admitted to hospital with first onset atrial fibrillation (AF) to determine the probability of spontaneous conversion to sinus rhythm and to identify factors predictive of such a conversion. Methods and Results  We retrospectively reviewed charts of 438...

  12. Attitudes Towards Catheter Ablation for Atrial Fibrillation

    DEFF Research Database (Denmark)

    Vadmann, Henrik; Pedersen, Susanne S; Nielsen, Jens Cosedis;

    2015-01-01

    BACKGROUND: Catheter ablation for atrial fibrillation (AF) is an important but expensive procedure that is the subject of some debate. Physicians´ attitudes towards catheter ablation may influence promotion and patient acceptance. This is the first study to examine the attitudes of Danish...

  13. Genetic aspects of lone atrial fibrillation

    DEFF Research Database (Denmark)

    Andreasen, Laura; Nielsen, Jonas B; Olesen, Morten S

    2015-01-01

    Atrial fibrillation (AF) is the most common cardiac arrhythmia. A subgroup of patients presents with AF without traditional risk factors and is diagnosed before the age of 60 years. Such patients are commonly referred as having "lone AF" and comprise 10-20% of all cases. A number of studies have...

  14. Genetic Risk Prediction of Atrial Fibrillation

    NARCIS (Netherlands)

    Lubitz, Steven A; Yin, Xiaoyan; Lin, Henry; Kolek, Matthew; Smith, J Gustav; Trompet, Stella; Rienstra, Michiel; Rost, Natalia S; Teixeira, Pedro; Almgren, Peter; Anderson, Christopher D; Chen, Lin Y; Engström, Gunnar; Ford, Ian; Furie, Karen L; Guo, Xiuqing; Larson, Martin G; Lunetta, Kathryn; Macfarlane, Peter W; Psaty, Bruce M; Soliman, Elsayed Z; Sotoodehnia, Nona; Stott, David J; Taylor, Kent D; Weng, Lu-Chen; Yao, Jie; Geelhoed, Bastiaan; Verweij, Niek; Siland, Joylene E; Kathiresan, Sekar; Roselli, Carolina; Roden, Dan M; van der Harst, Pim; Darbar, Dawood; Jukema, J Wouter; Melander, Olle; Rosand, Jonathan; Rotter, Jerome I; Heckbert, Susan R; Ellinor, Patrick T; Alonso, Alvaro; Benjamin, Emelia J

    2016-01-01

    BACKGROUND: -Atrial fibrillation (AF) has a substantial genetic basis. Identification of individuals at greatest AF risk could minimize the incidence of cardioembolic stroke. METHODS: -To determine whether genetic data can stratify risk for development of AF, we examined associations between AF gene

  15. Imaging in percutaneous ablation for atrial fibrillation

    NARCIS (Netherlands)

    R. Maksimović (Ružica); T. Dill (Thorsten); A.D. Ristić (Arsen); P.M. Seferovic (Petar)

    2006-01-01

    textabstractPercutaneous ablation for electrical disconnection of the arrhythmogenic foci using various forms of energy has become a well-established technique for treating atrial fibrillation (AF). Success rate in preventing recurrence of AF episodes is high although associated with a significant

  16. Corticosteroids and the risk of atrial fibrillation

    NARCIS (Netherlands)

    van der Hooft, CS; Heeringa, J; Brusselle, GG; Hofman, A; Witteman, JCM; Kingma, JH; Sturkenboom, MCJM; Stricker, BHC

    2006-01-01

    Background: High-dose ( pulse) corticosteroid therapy has been associated with the development of atrial fibrillation. This association, however, is mainly based on case reports. Methods: To test the hypothesis that high-dose corticosteroid exposure increases the risk of new-onset atrial fibrillatio

  17. Aggregation and fibrillation of bovine serum albumin

    DEFF Research Database (Denmark)

    Holm, NK; Jespersen, SK; Thomassen, LV;

    2007-01-01

    The all-alpha helix multi-domain protein bovine serum albumin (BSA) aggregates at elevated temperatures. Here we show that these thermal aggregates have amyloid properties. They bind the fibril-specific dyes Thioflavin T and Congo Red, show elongated although somewhat worm-like morphology...

  18. Islet amyloid polypeptide forms rigid lipid-protein amyloid fibrils on supported phospholipid bilayers.

    Science.gov (United States)

    Domanov, Yegor A; Kinnunen, Paavo K J

    2008-02-08

    Islet amyloid polypeptide (IAPP) forms fibrillar amyloid deposits in the pancreatic islets of Langerhans of patients with type 2 diabetes mellitus, and its misfolding and aggregation are thought to contribute to beta-cell death. Increasing evidence suggests that IAPP fibrillization is strongly influenced by lipid membranes and, vice versa, that the membrane architecture and integrity are severely affected by amyloid growth. Here, we report direct fluorescence microscopic observations of the morphological transformations accompanying IAPP fibrillization on the surface of supported lipid membranes. Within minutes of application in submicromolar concentrations, IAPP caused extensive remodeling of the membrane including formation of defects, vesiculation, and tubulation. The effects of IAPP concentration, ionic strength, and the presence of amyloid seeds on the bilayer perturbation and peptide aggregation were examined. Growth of amyloid fibrils was visualized using fluorescently labeled IAPP or thioflavin T staining. Two-color imaging of the peptide and membranes revealed that the fibrils were initially composed of the peptide only, and vesiculation occurred in the points where growing fibers touched the lipid membrane. Interestingly, after 2-5 h of incubation, IAPP fibers became "wrapped" by lipid membranes derived from the supported membrane. Progressive increase in molecular-level association between amyloid and membranes in the maturing fibers was confirmed by Förster resonance energy transfer spectroscopy.

  19. Das Tal von Kathmandu uns seine historische Stadtlandschaft: ein neues Konzept einer zu beschuetzenden Kulturlandschaft

    Directory of Open Access Journals (Sweden)

    Luca Rossato

    2012-08-01

    Full Text Available Die Stadtlandschaften der historischen Gebiete, die unter dem Schutz der UNESCO stehen, sind in ihrer Ganzheit zu schuetzen, sei es physisch als auch funktionell, so wie in ihren Schoenheit. Besonders in den Entwicklungslaendern hat die zeitgenoessische Bebauungspolitik in den letzen Jahren die Stadtszene von Orten, die in der Liste des Weltkulturerbes stehen, sehr untergraben. Der Katmandu Valley World Heritage Site, der ein Beispiel fuer kuenstelische Bluete der Himalayazone darstellt, ist nun bedrorht von Wirtschaftsentwicklung und Massenbebauung, und erlebt dadurch einen zunehmenden Verlust von “Kulturerbezugehoerigkeit” und damit auch Verlust seiner Werte. An diesem Fall erkennt man die Notwendigkeit einer neuer Methode, die die zeitgenossische Architektur in die historischen Gebiete einwachsen laesst und wirksammer Strategien (durchfuehrbare die die aeltesten Landschaften der Entwicklungs.laender zu schuetzen verstehen.

  20. [The birth of metapsychology. On the current interpretation of "Entwurf einer Psychologie" (1895)].

    Science.gov (United States)

    Schmidt-Hellerau, C

    1995-12-01

    The general attitude towards Entwurf einer Psychologie (1895) is to reckon it among Freud's pre-analytic writings, i.e. that part of his work later more or less disowned by the author. Schmidt-Hellerau challenges this assessment by Freud and many of his successors, demonstrating that the Entwurf can legitimately be regarded as a meta-theory resolving - or skirting- the old classification problem of whether psychoanalysis is a science or an art by connecting the hitherto dissociated spheres of soma and psyche and conceptualizing of physiological and psychological processes. See thus, the Entwurf reveals itself as a theoretical document of astonishing modernity and undiminished relevance in that it records Freud's ambitious attempt to overcome the mind-body schism and the divide between neurophysiology and psychology. And it is precisely this problem, the author contends, which Freud's later metapsychology--and the controversies it has aroused--revolves around.

  1. Hyaluronan (Erectus(R in der Behandlung der Osteoarthritis (OA des Kniegelenks - Ergebnisse einer offenen Anwendungsbeobachtung

    Directory of Open Access Journals (Sweden)

    Leeb BF

    2007-01-01

    Full Text Available Ziel der Untersuchung war es, praxisrelevante Daten hinsichtlich der Wirksamkeit, Verträglichkeit und Auswirkung auf die Lebensqualität einer in Österreich neu zugelassenen Hyaluronan-Präparation (Erectus(R; MW 1.100 KD zu erhalten. Patienten und Methodik: Zu diesem Zweck wurden 204 Patienten mit OA des Kniegelenkes, Kellgren-Lawrence (KL I–III (mean 61,1 a [31 a–100 a]; mean BMI 26,9; 57,2% weiblich, 42,8 % männlich von Oktober 2005 bis April 2006 in diese offene multizentrische Anwendungsbeobachtung eingeschlossen. Die Patienten erhielten fünf Injektionen Erectus(Rintraartikulär im Abstand von einer Woche. Primärer Endpunkt war die Verbesserung des Ruheschmerzes zu Visite 5 (Woche 5. Sekundäre Endpunkte waren Verbesserung des Ruheschmerzes bei Visite 6 (Woche 13 sowie des Bewegungsschmerzes, der Beweglichkeit und der Zufriedenheit mit der Lebenssituation. Alle Parameter wurden von den Patienten anhand einer Likert-Skala (0–10 beurteilt. Darüber hinaus erfolgte die Beurteilung von Gesamtwirksamkeit, Verträglichkeit und Gesamtzufriedenheit durch Prüfarzt und PatientIn. Die statistische Auswertung erfolgte mittels T-Test und Chi-Quadrat-Test. Fehlende Werte wurden gemäß LOCF ersetzt. Ergebnisse: Der Ruheschmerz wurde von den Patienten zu Beginn mit im Mittel 4,68 angegeben und verbesserte sich auf 2,04 bei Visite 5 bzw. auf 1,8 bei Visite 6 (p 0,01. Die Verbesserung war bei Patienten mit KL Grad I am stärksten und bei KL III am geringsten ausgeprägt. Die subjektive Beurteilung der Beweglichkeit sowie die Zufriedenheit, mit dem aktuellen Krankheitszustand längerfristig leben zu müssen, verbesserte sich ebenfalls signifikant (p 0,01, wobei dabei interessanterweise die stärksten Veränderungen bei Patienten mit KL III festzustellen waren. Patienten und Behandler beurteilten die globale Wirksamkeit parallel positiv, wie auch die Verträglichkeit. Die Beurteilung der Gesamtzufriedenheit nach einem Schulnotensystem (1–5 ergab

  2. Provokative Elemente einer Didaktik internetgestützter Lehr-Lernarrangements

    Directory of Open Access Journals (Sweden)

    Wolfgang Müskens

    2002-10-01

    Full Text Available Onlinebasiertes kollaboratives Lernen erfordert eine neue Rolle der Lehrenden und damit verbunden auch neue didaktische Methoden. Ausgehend vom Begriff der Provokation wird eine solche Didaktik in Abgrenzung zur Vorstellung eines ausschliesslich selbstgesteuerten Lernens entwickelt. Provokation wird in diesem Zusammenhang als die intendierte Konfrontation eines Lernenden mit einstellungskonträrem Material verstanden. Die Grundlagen der hier vorgestellten Didaktik werden aus einer Vielzahl theoretischer Wurzeln und empirischer Forschungsergebnisse hergeleitet: Es wird auf die Beziehung zum Kompetenzbegriff, zur Systemtheorie, zur Emotionspsychologie, zur Induzierung kognitiver Konflikte, zur Dissonanztheorie und zu Kellys Theorie der persönlichen Konstrukte eingegangen. Als konkrete Methoden der provokativen Didaktik für das E-Learning werden u. a. provokative Statements, das Induzieren einstellungskonträrer Perspektiven und eine an die «Fixed-Role-Therapy» angelehnte Aufgabenstellung diskutiert. Die Methoden der provokativen Didaktik bedeuten eine hochgradige Individualisierung des Lernens und eine Intensivierung des Verhältnisses zwischen Lerner und Lehrendem.

  3. Vom Text zum Bild – Überlegungen zu einer visuellen Grounded-Theory-Methodologie

    Directory of Open Access Journals (Sweden)

    Günter Mey

    2016-04-01

    Full Text Available Ausgehend von der für die Grounded-Theory-Methodologie (GTM zentralen Prämisse des "all is data" und vor dem Hintergrund zunehmender Beschäftigung mit visuellen Daten in der qualitativen Forschung, bietet der Beitrag einen orientierenden Rahmen für eine visuelle Grounded-Theory-Methodologie. Aufbauend auf Überlegungen aus der objektiven Hermeneutik, der dokumentarischen Methode, der Segmentanalyse sowie GTM-internen Perspektiven wird gezeigt, wie dieser traditionell textorientierte Ansatz auf visuelle Daten bezogen werden kann. Im Zentrum steht dabei die (Re- Formulierung der Verfahrensschritte Inventarisierung, Segmentierung, Kodierung/Kategorienbildung inkl. Memowriting sowie Sampling zur Untersuchung von Bildern im Sinne einer GTM-Logik. URN: http://nbn-resolving.de/urn:nbn:de:0114-fqs160225

  4. Catheter ablation of persistent atrial fibrillation in a patient with dextrocardia

    Institute of Scientific and Technical Information of China (English)

    XUE Zeng-ming; SANG Cai-hua; DONG Jian-zeng; MA Chang-sheng

    2012-01-01

    The technique of catheter ablation for atrial fibrillation (AF) has advanced rapidly over the last ten years.Catheter ablation of AF with special anatomy like dextrocardia was seldomly reported,1,2 which may be difficult for its complex anatomy.Three-dimensional electroanatomical mapping system and image integration system may be helpful during the procedure.We report a case with drug refractory persistent AF and dextrocardia,who underwent an ablation procedure.%Dextrocardia is a rare anomaly where the heart is located on the right side of the chest instead of the normal left side.Ablation of atrial fibrillation (AF) with such an inverted anatomy may be challenging for the manipulation of the catheters.Here we report a case of dextrocardia who underwent ablation for persistent AF guided by image integration system.

  5. Influence of hormone substitution therapy on postmenopausal uterus; Einfluss einer Hormonsubstitution auf den postmenopausalen Uterus

    Energy Technology Data Exchange (ETDEWEB)

    Otte, A.; Ruedisueli, A.; Goetze, M.; Leibundgut, U.; Mueller-Brand, J. [Inst. fuer Nuklearmedizin, Kantonsspital, Universitaetskliniken, Basel (Switzerland); Nitzsche, E.U. [Abt. Nuklearmedizin, Radiologische Universitaetsklinik, Freiburg (Germany)

    1997-12-01

    In a 58-year-old postmenopausal woman blood flow and blood pool images of bone scintigraphy showed a focus of increased activity in the right pelvic region. Computed tomography and ultrasound exhibited no abnormalities in the abdomen; especially the uterus and ovaries were normal. Careful anamnestic evaluation revealed that the patient received a long-term peroral estrogen/gestagen replacement therapy for the prevention of osteoporosis, but did not have menstruation-like bleedings for the last twelve months of therapy. At time of admission, the patient was on day 25 of hormone replacement therapy, and the uterus wash, therefore, in a premenstrual stage. Hence, despite cessation of bleedings in postmenopausal women, one should think of hormone replacement therapy as an explanation for vascular pelvic tumors seen by the first two phases of bone scintigraphy, before further diagnostic steps are undertaken. (orig.) [Deutsch] Bei der Skelettszintigraphie einer 58jaehrigen postmenopausalen Frau erkannte man in der Perfusions- und Blood-pool-Phase einen unklaren Fokus erhoehter Aktivitaet im rechten Becken. Computertomographie und Sonographie des Abdomens, insbesondere des Uterus und der Ovarien, waren unauffaellig. Nach eingehender anamnestischer Befragung stellte sich heraus, dass die Patientin unter einer mehrjaehrigen peroralen Oestrogen-/Gestagen-Hormonsubstitutionstherapie zur Osteoporose-Prophylaxe stand, jedoch seit den letzten zwoelf Monaten der Therapie ueber keine menstruationsaehnlichen Abbruchblutungen mehr berichten konnte. Bei ihrer Zuweisung befand sich die Patientin am 25. Tag der Hormonsubstitutionstherapie und ihr Uterus somit in einem praemenstruellen Stadium. Trotz Ausbleibens der Blutung bei postmenopausalen Frauen sollte somit an die Moeglichkeit der Hormonsubstitution gedacht und danach gefragt werden, wenn in den ersten beiden Phasen der Skelettszintigraphie eine unklare, gut vaskularisierte Struktur im kleinen Becken gefunden wird, bevor weitere

  6. Uniform spatial distribution of collagen fibril radii within tendon implies local activation of pC-collagen at individual fibrils

    CERN Document Server

    Rutenberg, Andrew D; Kreplak, Laurent

    2016-01-01

    Collagen fibril cross-sectional radii show no systematic variation between the interior and the periphery of fibril bundles, indicating an effectively constant rate of collagen incorporation into fibrils throughout the bundle. Such spatially homogeneous incorporation constrains the extracellular diffusion of collagen precursors from sources at the bundle boundary to sinks at the growing fibrils. With a coarse-grained diffusion equation we determine stringent bounds, using parameters extracted from published experimental measurements of tendon development. From the lack of new fibril formation after birth, we further require that the concentration of diffusing precursors stays below the critical concentration for fibril nucleation. We find that the combination of the diffusive bound, which requires larger concentrations to ensure homogeneous fibril radii, and lack of nucleation, which requires lower concentrations, is only marginally consistent with fully-processed collagen using conservative bounds. More real...

  7. Vitamin D-Defizit, Knochendichte und osteologische Marker des Knochenstoffwechsels bei türkischen Migranten in Deutschland im Vergleich zu einer deutschen Kontrollgruppe

    OpenAIRE

    Selseleh-Zarkesh, Omid

    2009-01-01

    Bei dem Krankheitsbild der Osteomalazie handelt es sich um eine systemische Erkrankung des Knochens infolge einer Mineralisationsstörung. Diese ist meist durch einen Vitamin D-Mangel bedingt, seltener durch eine Störung des Phosphatstoffwechsels. Eine reduzierte Knochendichte, wie sie bei der Osteomalazie und Osteoporose zu finden ist, geht mit einer Risikoerhöhung für knöcherne Frakturen wie auch mit einer erhöhten Morbidität und Mortalität einher. Das Ziel der vorliegenden Arbeit galt de...

  8. Bending rigidity of type I collagen homotrimer fibrils

    Science.gov (United States)

    Han, Sejin; Leikin, Sergey; Losert, Wolfgang

    2009-03-01

    Normal type I collagen is an α1(I)2α2(I) heterotrimeric triple helix, but α1(I)3 homotrimers are also found in fetal tissues and various pathological conditions, e.g., causing bone fragility and reducing tendon tensile strength. It remains unclear whether homotrimers alter mechanical properties of individual fibrils or affect tissues by altering their organization at a higher level. To address this question, we investigated how homotrimers affect fibril bending rigidity. Homotrimer fibrils have been shown to be more loosely packed so that we expected them to be more susceptible to bending. However, homotrimer fibrils were more rigid despite being thinner and more hydrated. To quantify fibril rigidity, we analyzed their shape by Fourier decomposition, determined the correlation function for the direction along each fibril, and calculated the distribution of local fibril curvature. The estimated persistence length of homotrimer fibrils was 3 ˜ 10 times longer than for heterotrimer fibrils, indicating much higher bending rigidity of homotrimer fibrils.

  9. Aminothienopyridazines and methylene blue affect Tau fibrillization via cysteine oxidation.

    Science.gov (United States)

    Crowe, Alex; James, Michael J; Lee, Virginia M-Y; Smith, Amos B; Trojanowski, John Q; Ballatore, Carlo; Brunden, Kurt R

    2013-04-19

    Alzheimer disease and several other neurodegenerative disorders are characterized by the accumulation of intraneuronal fibrils comprised of the protein Tau. Tau is normally a soluble protein that stabilizes microtubules, with splice isoforms that contain either three (3-R) or four (4-R) microtubule binding repeats. The formation of Tau fibrils is thought to result in neuronal damage, and inhibitors of Tau fibrillization may hold promise as therapeutic agents. The process of Tau fibrillization can be replicated in vitro, and a number of small molecules have been identified that inhibit Tau fibril formation. However, little is known about how these molecules affect Tau fibrillization. Here, we examined the mechanism by which the previously described aminothieno pyridazine (ATPZ) series of compounds inhibit Tau fibrillization. Active ATPZs were found to promote the oxidation of the two cysteine residues within 4-R Tau by a redox cycling mechanism, resulting in the formation of a disulfide-containing compact monomer that was refractory to fibrillization. Moreover, the ATPZs facilitated intermolecular disulfide formation between 3-R Tau monomers, leading to dimers that were capable of fibrillization. The ATPZs also caused cysteine oxidation in molecules unrelated to Tau. Interestingly, methylene blue, an inhibitor of Tau fibrillization under evaluation in Alzheimer disease clinical trials, caused a similar oxidation of cysteines in Tau and other molecules. These findings reveal that the ATPZs and methylene blue act by a mechanism that may affect their viability as potential therapeutic agents.

  10. A setup for simultaneous measurement of infrared spectra and light scattering signals: Watching amyloid fibrils grow from intact proteins

    Energy Technology Data Exchange (ETDEWEB)

    Li, Yang; Maurer, Jürgen; Roth, Andreas; Vogel, Vitali; Winter, Ernst; Mäntele, Werner, E-mail: maentele@biophysik.uni-frankfurt.de [Institut für Biophysik, Goethe-Universität Frankfurt am Main, Max-von Laue-Straße 1, D-60438 Frankfurt am Main (Germany)

    2014-08-15

    A setup for the simultaneous measurement of mid-infrared spectra and static light scattering is described that can be used for the analysis of the formation of nanoscale and microscopic aggregates from smaller molecules to biopolymers. It can be easily integrated into sample chambers of infrared spectrometers or combined with laser beams from tunable infrared lasers. Here, its use for the analysis of the formation of amyloid fibrils from intact proteins is demonstrated. The formation of amyloid fibrils or plaques from proteins is a widespread and pathogenetic relevant process, and a number of diseases are caused and correlated with the deposition of amyloid fibrils in cells and tissues. The molecular mechanisms of these transformations, however, are still unclear. We report here the simultaneous measurement of infrared spectra and static light scattering for the analysis of fibril formation from egg-white lysozyme. The transformation of the native form into non-native forms rich in β-sheet structure is measured by analysis of the amide I spectral region in the infrared spectra, which is sensitive for local structures. At the same time, light scattering signals at forward direction as well as the forward/backward ratio, which are sensitive for the number of scattering centers and their approximate sizes, respectively, are collected for the analysis of fibril growth. Thermodynamic and kinetic parameters as well as mechanistic information are deduced from the combination of the two complementary techniques.

  11. Das Portfolio als Beitrag zur Reflexion persönlicher Kompetenzentwicklung in der Religions-/PädagogInnenbildung. Chancen einer neuen Lern- und Bewertungskultur - am Beispiel einer Fallstudie

    Directory of Open Access Journals (Sweden)

    Alexander van Dellen

    2013-10-01

    Full Text Available ”Competence orientation” in pedagogy education constitutes a central point within the draft laws formulated on the 12th of June 2013. These see the use of portfolios as playing a crucial part of religious instruction education. This is based on the expectation that portfolios act as continuous and helpful companions throughout the various educational phases and therefore benefit students’ reflections on individual competence development. Portfolios allow effective measures towards personal development as a professional educator to be taken. The format at hand, which was conceived as a case study at the Institute for Practical Theology (department catechetics, religious education studies and religious didactics at the Faculty of Catholic Theology at the University of Innsbruck, is intended to be used as a basis for a discussion on the benefits of a continuous portfolio as a reflection tool for students’ personal competence development. The first step illustrates the genesis and structure of the portfolio concept (2, so that the second step can then outline the potentials held by this new culture of using portfolios as learning and assessment tools in religious instruction education (3. In den vom österreichischen Parlament am 12. Juni 2013 beschlossenen Gesetzesentwürfen zur zukünftigen PädagogInnenbildung stellt die Kompetenzorientierung einen Kernpunkt dar. In diesem Zusammenhang wird in der Ausbildung von Religions-/PädagogInnen der Einsatz von Portfolios verstärkt eine zentrale Rolle spielen. Damit ist die Hoffnung verbunden, dass das Portfolio als Kontinuum in den unterschiedlichen Phasen der Religions-/PädagogInnenbildung für Studierende ein hilfreiches Instrument für die Reflexion ihrer individuellen Kompetenzentwicklung bildet. Somit kann eine wirksame Maßnahme der persönlichen Entwicklung in der Professionalisierung für den Lehrberuf gesetzt werden. In den vorliegenden Ausführungen soll auf der Grundlage einer

  12. Dronedarone for atrial fibrillation: a new therapeutic agent

    Directory of Open Access Journals (Sweden)

    Pawan D Patel

    2009-08-01

    Full Text Available Pawan D Patel, Rohit Bhuriya, Dipal D Patel, Bhaskar L Arora, Param P Singh, Rohit R AroraDepartment of Cardiology, Chicago Medical School, Chicago, IL, USAAbstract: Atrial fibrillation is the most common of the serious cardiac rhythm disturbances and is responsible for substantial morbidity and mortality. Amiodarone is currently one of the most widely used and most effective antiarrhythmic agents for atrial fibrillation. But during chronic usage amiodarone can cause some serious extra cardiac adverse effects, including effects on the thyroid. Dronedarone is a newer therapeutic agent with a structural resemblance to amiodarone, with two molecular changes, and with a better side effect profile. Dronedarone is a multichannel blocker and, like amiodarone, possesses both a rhythm and a rate control property in atrial fibrillation. The US Food and Drug Administration approved dronedarone for atrial fibrillation on July 2, 2009. In this review, we discuss the role of dronedarone in atrial fibrillation.Keywords: dronedarone, amiodarone, atrial fibrillation

  13. Preparation of Amyloid Fibrils Seeded from Brain and Meninges.

    Science.gov (United States)

    Scherpelz, Kathryn P; Lu, Jun-Xia; Tycko, Robert; Meredith, Stephen C

    2016-01-01

    Seeding of amyloid fibrils into fresh solutions of the same peptide or protein in disaggregated form leads to the formation of replicate fibrils, with close structural similarity or identity to the original fibrillar seeds. Here we describe procedures for isolating fibrils composed mainly of β-amyloid (Aβ) from human brain and from leptomeninges, a source of cerebral blood vessels, for investigating Alzheimer's disease and cerebral amyloid angiopathy. We also describe methods for seeding isotopically labeled, disaggregated Aβ peptide solutions for study using solid-state NMR and other techniques. These methods should be applicable to other types of amyloid fibrils, to Aβ fibrils from mice or other species, tissues other than brain, and to some non-fibrillar aggregates. These procedures allow for the examination of authentic amyloid fibrils and other protein aggregates from biological tissues without the need for labeling the tissue.

  14. Atrial fibrillation associated with subclinical hyperthyroidism.

    Science.gov (United States)

    Patanè, Salvatore; Marte, Filippo

    2009-05-29

    Subclinical hyperthyroidism is an increasingly recognized entity that is defined as a normal serum free thyroxine and free triiodothyronine levels with a thyroid-stimulating hormone level suppressed below the normal range and usually undetectable. It has been reported that subclinical hyperthyroidism is not associated with coronary heart disease or mortality from cardiovascular causes but it is sufficient to induce arrhythmias including atrial fibrillation and atrial flutter. It has also been reported that increased factor X activity in patients with subclinical hyperthyroidism represents a potential hypercoagulable state. We present a case of atrial fibrillation associated with subclinical hyperthyroidism, in a 78-year-old Italian woman. Also this case focuses attention on the importance of a correct evaluation of subclinical hyperthyroidism.

  15. [Atrial fibrillation ablation: application of nurse methodology].

    Science.gov (United States)

    Ramos-González-Serna, Amelia; Mateos-García, M Dolores

    2011-01-01

    Ablation of pulmonary veins for treatment of atrial fibrillation involves applying radiofrequency energy wave by a catheter that causes a circumferential lesion to achieve electrical isolation and voltage drop in the interior. It is mainly applied when there is resistance to treatment and recurrence of symptoms affecting the quality of life of patients. The nurse is an important part of the multidisciplinary team who care for patients who undergo this procedure. The provision of comprehensive nursing care should include nursing procedures prior to, during, and after treatment to ensure the careful and systematic quality required. The aims of this article are: to provide specialised knowledge on the procedure of atrial fibrillation ablation, to describe the preparation of the electrophysiology laboratory, analyse nursing care and develop a standardized care plan for patients on whom this procedure is performed using the NANDA (North American Nursing Association) taxonomy and NIC (Nursing Intervention Classification).

  16. Die Veränderung der Grenzen in einer transnationalen Gebietskörperschaft

    Directory of Open Access Journals (Sweden)

    Karen Denni

    2009-12-01

    Full Text Available L’objet de notre article est de mettre en lumière la multiplicité des frontières qui structurent la zone frontalière de Strasbourg-Ortenau. Au cours de son histoire, la frontière francoallemande a considérablement évolué. Zone conflictuelle de rupture comme lors de la guerre franco-allemande de 1870-1871, elle représente désormais un espace pacifié et intégré dans un ensemble politique européen plus large. La convention pour la création d’un eurodistrict franco-allemand conclue en 2005 prévoit même le dépassement des frontières politiques et administratives en visant la fusion de ces deux collectivités contiguës séparées par le Rhin et concourt, grâce à la proximité géographique et organisationnelle que permet la petite structure ainsi créée, à faciliter l’articulation entre l’échelle locale et l’échelle globale. Mais, malgré cette convention qui a intensifié la coopération transfrontalière, ce projet suscite encore de nombreuses interrogations aux plans juridique, politique et social. En outre, les citoyens français et allemands de la zone du Rhin supérieur restent finalement assez peu informés de l’importante progression que connaît la coopération transfrontalière dans ce secteur et n’y voient que peu d’avantages. Une plus large implication des citoyens à ce projet semble indispensable afin que ceux-ci apportent créativité et dynamisme à la construction d’une nouvelle entité politique dans laquelle il leur sera alors possible de s’identifier. Un long chemin reste donc à parcourir avant que le Rhin cesse de représenter une frontière entre la France et l’Allemagne et se transforme en un véritable trait d’union entre ces deux pays.Ziel dieses Artikels ist es, die vielfältigen Aspekte der Grenzen darzulegen, die den Grenzraum Straßburg-Kehl strukturieren. Im Laufe ihrer Geschichte hat die deutsch-französische Grenze einen großen Wandel vollzogen, von einer

  17. [Ventricular fibrillation following deodorant spray inhalation].

    Science.gov (United States)

    Girard, F; Le Tacon, S; Maria, M; Pierrard, O; Monin, P

    2008-01-01

    We report one case of out-of-hospital cardiac arrest with ventricular fibrillation following butane poisoning after inhalation of antiperspiration aerosol. An early management using semi-automatic defibrillator explained the success of the resuscitation. The mechanism of butane toxicity could be an increased sensitivity of cardiac receptors to circulating catecholamines, responsible for cardiac arrest during exercise and for resuscitation difficulties. The indication of epinephrine is discussed.

  18. Atrial fibrillation in obstructive sleep apnea

    OpenAIRE

    Goyal, Sandeep K; Sharma, Abhishek

    2013-01-01

    Atrial fibrillation (AF) is a common arrhythmia with rising incidence. Obstructive sleep apnea (OSA) is prevalent among patients with AF. This observation has prompted significant research in understanding the relationship between OSA and AF. Multiple studies support a role of OSA in the initiation and progression of AF. This association has been independent of obesity, body mass index and hypertension. Instability of autonomic tone and wide swings in intrathoracic pressure are seen in OSA. T...

  19. Acute atrial fibrillation during dengue hemorrhagic fever

    Directory of Open Access Journals (Sweden)

    Veloso Henrique Horta

    2003-01-01

    Full Text Available Dengue fever is a viral infection transmitted by the mosquito, Aedes aegypti. Cardiac rhythm disorders, such as atrioventricular blocks and ventricular ectopic beats, appear during infection and are attributed to viral myocarditis. However, supraventricular arrhythmias have not been reported. We present a case of acute atrial fibrillation, with a rapid ventricular rate, successfully treated with intravenous amiodarone, in a 62-year-old man with dengue hemorrhagic fever, who had no structural heart disease.

  20. Cardiac fibrillation risk of Taser weapons.

    Science.gov (United States)

    Leitgeb, Norbert

    2014-06-01

    The debate on potential health hazards associated with delivering electric discharges to incapacitated subjects, in particular on whether electric discharge weapons are lethal, less lethal or non-lethal, is still controversial. The cardiac fibrillation risks of Taser weapons X26 and X3 have been investigated by measuring the delivered high-tension pulses in dependence on load impedance. Excitation thresholds and sinus-to-Taser conversion factors have been determined by numerical modeling of endocardial, myocardial, and epicardial cells. Detailed quantitative assessment of cardiac electric exposure has been performed by numerical simulation at the normal-weighted anatomical model NORMAN. The impact of anatomical variation has been quantified at an overweight model (Visible Man), both with a spatial resolution of 2 × 2 × 2 mm voxels. Spacing and location of dart electrodes were systematically varied and the worst-case position determined. Based on volume-weighted cardiac exposure assessment, the fibrillation probability of the worst-case hit was determined to 30% (Taser X26) and 9% (Taser X3). The overall risk assessment of Taser application accounting for realistic spatial hit distributions was derived from training sessions of police officers under realistic scenarios and by accounting for the influence of body (over-)weight as well as gender. The analysis of the results showed that the overall fibrillation risk of Taser use is not negligible. It is higher at Taser X26 than at Taser X3 and amounts to about 1% for Europeans with an about 20% higher risk for Asians. Results demonstrate that enhancement as well as further reduction of fibrillation risk depends on responsible use or abuse of Taser weapons.

  1. Atrial Fibrillation During an Exploration Class Mission

    Science.gov (United States)

    Lipset, Mark A.; Lemery, Jay; Polk, J. D.; Hamilton, Douglas R.

    2010-01-01

    Background: A long-duration exploration class mission is fraught with numerous medical contingency plans. Herein, we explore the challenges of symptomatic atrial fibrillation (AF) occurring during an exploration class mission. The actions and resources required to ameliorate the situation, including the availability of appropriate pharmaceuticals, monitoring devices, treatment modalities, and communication protocols will be investigated. Challenges of Atrial Fibrillation during an Exploration Mission: Numerous etiologies are responsible for the initiation of AF. On Earth, we have the time and medical resources to evaluate and determine the causative situation for most cases of AF and initiate therapy accordingly. During a long-duration exploration class mission resources will be severely restricted. How is one to determine if new onset AF is due to recent myocardial infarction, pulmonary embolism, fluid overload, thyrotoxicosis, cardiac structural abnormalities, or CO poisoning? Which pharmaceutical therapy should be initiated and what potential side effects can be expected? Should anti-coagulation therapy be initiated? How would one monitor the therapeutic treatment of AF in microgravity? What training would medical officers require, and which communication strategies should be developed to enable the best, safest therapeutic options for treatment of AF during a long-duration exploration class mission? Summary: These questions will be investigated with expert opinion on disease elucidation, efficient pharmacology, therapeutic monitoring, telecommunication strategies, and mission cost parameters with emphasis on atrial fibrillation being just one illustration of the tremendous challenges that face a long-duration exploration mission. The limited crew training time, medical hardware, and drugs manifested to deal with such an event predicate that aggressive primary and secondary prevention strategies be developed to protect a multibillion-dollar asset like the

  2. STRATEGIES OF PROPHYLAXIS AND MANAGEMENT OF POSTOPERATIVE ATRIAL FIBRILLATION

    Directory of Open Access Journals (Sweden)

    Dembele, A.

    2016-07-01

    Full Text Available This article analyses different strategies of prophylaxis and management of postoperative atrial fibrillation in patients undergoing coronary artery bypass grafting (CABG at different periods after acute myocardial infarction (AMI. It examines the efficacy of early administration of beta-adrenergic blocking agents (metoprolol and amiodarone (in prophylactic doses in the diminution of the risk of postoperative atrial fibrillation in different groups of patients. The article also discerns the effectiveness of digoxin in the management of episodes of postoperative atrial fibrillation.

  3. Genetics of Atrial Fibrillation and Possible Implications for Ischemic Stroke

    OpenAIRE

    Robin Lemmens; Sylvia Hermans; Dieter Nuyens; Vincent Thijs

    2011-01-01

    Atrial fibrillation is the most common cardiac arrhythmia mainly caused by valvular, ischemic, hypertensive, and myopathic heart disease. Atrial fibrillation can occur in families suggesting a genetic background especially in younger subjects. Additionally recent studies have identified common genetic variants to be associated with atrial fibrillation in the general population. This cardiac arrhythmia has important public health implications because of its main complications: congestive heart...

  4. Die Kraft einer phänomenologischen Haltung. Reflexionen aus der Praxis des Religionsunterrichtes.

    Directory of Open Access Journals (Sweden)

    Joachim Hawel

    2014-07-01

    Full Text Available ENGLISH: Initially the terms ‚phenomenological‘ and ‚phenomenological attitude‘ respectively will be explicated. The phenomenological attitude is an attitude of mental and spiritual looking, which distinguishes between ‚feeling first‘ and ‚thinking later‘, it seeks to avoid, that, when problems in religious education class present themselves, by a rash assessment ‚That’s how it is‘ the personhood of the student and the personhood of the teacher are neglected. This attitude has several prerequisites, above all has to be the conscious decision for this attitude, which must be practiced and reflected a whole professional life. In the main part of the article six elements of a phenomenological attitude will be explained, the last of which relates to the ‚phenomenology of life‘ by Michel Henry, which points out, that the most essential part, namely life itself, is beyond visibility, which has drastic consequences for religious education – or any education for that matter. The ‚lifelong practicing‘ of this attitude also requires an extra occupational continuous development of the personality, which can also serve as burnout prophylaxis. DEUTSCH: Zunächst werden die Begriffe ‚phänomenologisch‘ bzw. ‚phänomenologische Haltung‘ expliziert. Die phänomenologische Haltung ist eine Haltung geistigen Schauens, die zwischen ‚Vor-Fühlen‘ und ‚Nach-Denken‘ unterscheidet, sie versucht zu vermeiden, dass man bei Problemen im Religionsunterricht durch die vorschnelle Feststellung ‚So ist es‘ das Person-Sein der SchülerInnen und das Person-Sein der Lehrenden außer Acht lässt. Diese Haltung hat mehrere Voraussetzungen, zuallererst bedarf es der bewussten Entscheidung für diese Haltung, die ein Berufsleben lang eingeübt bzw. reflektiert werden muss. Sechs Elemente einer phänomenologischen Haltung werden im Hauptteil des Artikels ausgeführt, das letzte Element bezieht sich auf die

  5. Untersuchung zur Verbesserung des Vitamin-D-Stoffwechsels bei Altersheimbewohnern mittels einer Bestrahlung mit ultraviolettem Licht

    Directory of Open Access Journals (Sweden)

    Scharla SH

    2006-01-01

    Full Text Available Vitamin-D-Mangel ist ein bedeutender Risikofaktor für Knochenbrüche im Alter. Die vorliegende Untersuchung überprüfte die Wirkung einer künstlichen UV-Licht-Bestrahlung auf den Vitamin D-Status, die Parathormonkonzentration im Serum sowie den Knochenabbaumarker NTX im Urin (NTX = quervernetzte N-Telopeptide aus Kollagen Typ 1 bei älteren Frauen im Altersheim. Die UV-Licht-Bestrahlung wurde mit 3 verschiedenen kommerziellen Lampen durchgeführt, die nicht primär für medizinische Anwendungen vorgesehen waren. Es wurden insgesamt 18 Bestrahlungseinheiten über 6 Wochen durchgeführt, wobei die Bestrahlungsdosis jeweils 30 bis 40% der minimalen Erythemschwellendosis betrug. Die Bestrahlung wurde von den Probanden ohne Nebenwirkungen gut vertragen. Vor Beginn der Bestrahlung (im Spätwinter, Februar war der Vitamin-D-Versorgungsgrad der Altersheimbewohnerinnen sehr schlecht (25-Hydroxyvitamin D 25 nmol/l bei mehr als 80 % der Frauen, weiterhin war der Knochenabbaumarker NTX deutlich erhöht. Es kam unter Bestrahlung und auch in der Nachbeobachtungszeit zu keiner signifikanten Änderung der Serumkonzentration von 25-Hydroxyvitamin D und Parathormon, der Knochenabbaumarker NTX zeigte in einer Gruppe einen leichten Rückgang. Es zeigte sich weiterhin eine erwartete inverse Korrelation der Serumkonzentration von Parathormon mit 25-Hydroxyvitamin D (r = –0,19; p 0,03 und überraschend eine positive Korrelation zwischen Kalzium und Parathormon (r = 0,24; p 0,02, auf eine autonomisierte Parathormonsekretion bei einigen Frauen hinweisend. Parathormon war weiterhin positiv mit dem Knochenabbaumarker NTX korreliert (r = 0,21; p 0,026, dagegen gab es keine signifikante Korrelation zwischen 25-Hydroxyvitamin D und dem Knochenabbaumarker NTX (p = 0,83 und auch nicht zwischen 25-Hydroxyvitamin D und der alkalischen Phosphatase (r = –0,04, p = 0,648. Fazit: Das durchgeführte Bestrahlungsprotokoll konnte den Vitamin D-Status nicht signifikant verbessern

  6. Glassy state of native collagen fibril?

    Science.gov (United States)

    Gevorkian, S. G.; Allahverdyan, A. E.; Gevorgyan, D. S.; Hu, C.-K.

    2011-07-01

    Our micromechanical experiments show that viscoelastic features of type-I collagen fibril at physiological temperatures display essential dependence on the frequency and speed of heating. For temperatures of 20-30 °C the internal friction has a sharp maximum for a frequency less than 2 kHz. Upon heating the internal friction displays a peak at a temperature Tsoft(v) that essentially depends on the speed of heating v: Tsoft≈70°C for v=1°C/min, and Tsoft≈25°C for v=0.1°C/min. At the same temperature Tsoft(v) Young's modulus passes through a minimum. All these effects are specific for the native state of the fibril and disappear after heat-denaturation. Taken together with the known facts that the fibril is axially ordered as quasicrystal, but disordered laterally, we interpret our findings as indications of a glassy state, where Tsoft is the softening transition.

  7. Medienpädagogik und digitaler Kapitalismus. Für die Stärkung einer gesellschafts- und medienkritischen Perspektive

    Directory of Open Access Journals (Sweden)

    Horst Niesyto

    2017-01-01

    Full Text Available Medienkritik gehörte schon immer zu den zentralen Aufgaben der Medienpädagogik. Die These ist, dass die Medienpädagogik bezüglich einer kritischen Medien- und Gesellschaftsanalyse einen Nachholbedarf hat. Nach einem Blick zurück auf historische Entwicklungslinien der Medienpädagogik wird begründet, weshalb die Stärkung einer gesellschafts- und medienkritischen Perspektive notwendig ist. In einem weiteren Schritt erfolgt eine Annäherung an das Thema ‹Digitaler Kapitalismus›, indem ausgewählte Beiträge aus verschiedenen wissenschaftlichen Perspektiven skizziert und wichtige Strukturprinzipen herausgearbeitet werden. Der abschliessende Teil thematisiert die gesellschaftliche Verantwortung der Medienpädagogik: Entweder immer mehr zu einem Ausbildungs- und Reparaturbetrieb des digitalen Kapitalismus zu werden (für digitale Technologien und deren ‹Nebenwirkungen› oder sich als kritisch-reflexive Begleitung von medienbezogenen Bildungs- und Lernprozessen zu verstehen.

  8. Economic analysis of alternative energies in a sewage system plant; Betriebswirtschaftliche Analyse alternativer Energien in einer Klaeranlage

    Energy Technology Data Exchange (ETDEWEB)

    Weszka, S. [Tech. Univ. Stettin (Poland); Ahlhaus, M. [Inst. fuer Energie und Umwelt e.V. (Germany)

    2000-06-01

    Using the example of the Nowogard, Poland, sewage plant, the contribution discusses the uses of alternative energy sources. First, the material balance of the sewage process was defined and technical concepts for utilisation of alternative energies were developed. This will be followed by economic analysis in order to identify the optimal process variant. [German] Die Verwendung alternativer Energiequellen kann auch in einer Klaeranlage realisiert werden. Am Beispiel der Klaeranlage Nowogard/Polen werden die konkreten Nutzungsmoeglichkeiten alternativer Energien untersucht. Zunaechst wird der Stofffluss des Klaerprozesses ermittelt und technische Konzepte zur Anwendung alternativer Energie aufgezeigt. Darauf aufbauend sollen betriebswirtschaftliche Analysen erfolgen, um die Vorzugsvariante der Energieversorgung einer Kaelteanlage aus technischer und oekonomischer Sicht abzuleiten. (orig.)

  9. 'Integration'

    DEFF Research Database (Denmark)

    Olwig, Karen Fog

    2011-01-01

    After a long history dominated by out-migration, Denmark, Norway and Sweden have, in the past 50 years, become immigration societies. This article compares how these Scandinavian welfare societies have sought to incorporate immigrants and refugees into their national communities. It suggests that......, while the countries have adopted disparate policies and ideologies, differences in the actual treatment and attitudes towards immigrants and refugees in everyday life are less clear, due to parallel integration programmes based on strong similarities in the welfare systems and in cultural notions...... of equality in the three societies. Finally, it shows that family relations play a central role in immigrants’ and refugees’ establishment of a new life in the receiving societies, even though the welfare society takes on many of the social and economic functions of the family....

  10. Die "Forschungsstelle Qualitative Methoden" an der Heinrich Heine-Universität Düsseldorf: Ansätze zu einer sozialwissenschaftlich angeregten Psychotherapieforschung

    OpenAIRE

    Stratkötter, Andreas

    2000-01-01

    Es wird die qualitative Forschungstätigkeit der Abteilung Psychosomatik an der Universität Düsseldorf vorgestellt. Die Auswahl und Entwicklung qualitativer Forschungsmethoden für unser Arbeitsfeld wird angesprochen, in einer Übersicht werden die bearbeiteten Themen präsentiert: Narrative und Selbstbeschreibungen in psychotherapeutischen Erstgesprächen; musiktherapeutische Improvisationen; das Krankheitserleben von Endometriose-Patientinnen; Perspektiven des Verlaufs einer teilstationär-psycho...

  11. Review: Patricia Arnold (2003). Kooperatives telematisches Lernen aus der Perspektive der Lernenden – Qualitative Analyse einer Community of Practice im Fernstudium

    OpenAIRE

    2006-01-01

    Welche Bedeutung kommt dem kooperativen Lernen im Zusammenhang mit dem Fernstudium zu? Kann das Internet dabei eine fördernde, unterstützende Rolle spielen? Diese Fragen untersucht Patricia ARNOLD in ihrer Dissertation, wobei sie sich auf das Fernstudium mit seinen besonderen Bedingungen des Lernens bezieht. In der vorliegenden qualitativ-empirischen Untersuchung einer Gemeinschaft von Fernstudierenden untersucht ARNOLD, wie selbst bestimmtes Lernen innerhalb einer Gruppe kooperativ und onlin...

  12. Toxic species in amyloid disorders: Oligomers or mature fibrils

    Directory of Open Access Journals (Sweden)

    Meenakshi Verma

    2015-01-01

    Full Text Available Protein aggregation is the hallmark of several neurodegenerative disorders. These protein aggregation (fibrillization disorders are also known as amyloid disorders. The mechanism of protein aggregation involves conformation switch of the native protein, oligomer formation leading to protofibrils and finally mature fibrils. Mature fibrils have long been considered as the cause of disease pathogenesis; however, recent evidences suggest oligomeric intermediates formed during fibrillization to be toxic. In this review, we have tried to address the ongoing debate for these toxic amyloid species. We did an extensive literature search and collated information from Pubmed (http://www.ncbi.nlm.nih.gov and Google search using various permutations and combinations of the following keywords: Neurodegeneration, amyloid disorders, protein aggregation, fibrils, oligomers, toxicity, Alzheimer′s Disease, Parkinson′s Disease. We describe different instances showing the toxicity of mature fibrils as well as oligomers in Alzheimer′s Disease and Parkinson′s Disease. Distinct structural framework and morphology of amyloid oligomers suggests difference in toxic effect between oligomers and fibrils. We highlight the difference in structure and proposed toxicity pathways for fibrils and oligomers. We also highlight the evidences indicating that intermediary oligomeric species can act as potential diagnostic biomarker. Since the formation of these toxic species follow a common structural switch among various amyloid disorders, the protein aggregation events can be targeted for developing broad-range therapeutics. The therapeutic trials based on the understanding of different protein conformers (monomers, oligomers, protofibrils and fibrils in amyloid cascade are also described.

  13. Amplification of Tau fibrils from minute quantities of seeds.

    Science.gov (United States)

    Meyer, Virginia; Dinkel, Paul D; Rickman Hager, Emily; Margittai, Martin

    2014-09-16

    The propagation of Tau pathology in Alzheimer's disease (AD) is thought to proceed through templated conversion of Tau protein into fibrils and cell-to-cell transfer of elongation-competent seeds. To investigate the efficiency of Tau conversion, we adapted the protein misfolding cyclic amplification assay used for the conversion of prions. Utilizing heparin as a cofactor and employing repetitive cycles of shearing and growth, synthetic Tau fibrils and Tau fibrils in AD brain extract are progressively amplified. Concurrently, self-nucleation is suppressed. The results highlight breakage-induced replication of Tau fibrils as a potential facilitator of disease spread.

  14. Evidence of structurally continuous collagen fibrils in tendons.

    Science.gov (United States)

    Svensson, Rene B; Herchenhan, Andreas; Starborg, Tobias; Larsen, Michael; Kadler, Karl E; Qvortrup, Klaus; Magnusson, S Peter

    2017-03-01

    Tendons transmit muscle-generated force through an extracellular matrix of aligned collagen fibrils. The force applied by the muscle at one end of a microscopic fibril has to be transmitted through the macroscopic length of the tendon by mechanisms that are poorly understood. A key element in this structure-function relationship is the collagen fibril length. During embryogenesis short fibrils are produced but they grow rapidly with maturation. There is some controversy regarding fibril length in adult tendon, with mechanical data generally supporting discontinuity while structural investigations favor continuity. This study initially set out to trace the full length of individual fibrils in adult human tendons, using serial block face-scanning electron microscopy. But even with this advanced technique the required length could not be covered. Instead a statistical approach was used on a large volume of fibrils in shorter image stacks. Only a single end was observed after tracking 67.5mm of combined fibril lengths, in support of fibril continuity. To shed more light on this observation, the full length of a short tendon (mouse stapedius, 125μm) was investigated and continuity of individual fibrils was confirmed. In light of these results, possible mechanisms that could reconcile the opposing findings on fibril continuity are discussed. Connective tissues hold all parts of the body together and are mostly constructed from thin threads of the protein collagen (called fibrils). Connective tissues provide mechanical strength and one of the most demanding tissues in this regard are tendons, which transmit the forces generated by muscles. The length of the collagen fibrils is essential to the mechanical strength and to the type of damage the tissue may experience (slippage of short fibrils or breakage of longer ones). This in turn is important for understanding the repair processes after such damage occurs. Currently the issue of fibril length is contentious, but this

  15. Mechanical properties of a collagen fibril under simulated degradation.

    Science.gov (United States)

    Malaspina, David C; Szleifer, Igal; Dhaher, Yasin

    2017-11-01

    Collagen fibrils are a very important component in most of the connective tissue in humans. An important process associated with several physiological and pathological states is the degradation of collagen. Collagen degradation is usually mediated by enzymatic and non-enzymatic processes. In this work we use molecular dynamics simulations to study the influence of simulated degradation on the mechanical properties of the collagen fibril. We applied tensile stress to the collagen fiber at different stages of degradation. We compared the difference in the fibril mechanical priorities due the removal of enzymatic crosslink, surface degradation and volumetric degradation. As anticipated, our results indicated that, regardless of the degradation scenario, fibril mechanical properties is reduced. The type of degradation mechanism (crosslink, surface or volumetric) expressed differential effect on the change in the fibril stiffness. Our simulation results showed dramatic change in the fibril stiffness with a small amount of degradation. This suggests that the hierarchical structure of the fibril is a key component for the toughness and is very sensitive to changes in the organization of the fibril. The overall results are intended to provide a theoretical framework for the understanding the mechanical behavior of collagen fibrils under degradation. Copyright © 2017 Elsevier Ltd. All rights reserved.

  16. Über Leben : einige Szenarien zu einer Ethik des Überlebens nach Foucault, Agamben und Ridley Scotts 'Alien'

    OpenAIRE

    Zakravsky, Katherina

    2017-01-01

    Das Aufkommen der Biopolitik als Dispositiv der Moderne beschreibt Michel Foucault als Effekt einer Reihe von Transformationen, verbindet es allerdings an dieser Stelle nicht explizit mit den wissenschaftlichen Entdeckungen Darwins. Die Eingliederung des Menschen in das Kontinuum der lebenden Organismen ist aber eine der bedeutsamsten Konsequenzen von Darwins Theorie von der Abstammung des Menschen. Wenn parallel zu oder auch in Abhängigkeit von dieser Transformation des biologischen Wissens ...

  17. Rezidivierende kurze depressive Störung. Übersicht und eigene klinische Erfahrungen zu einer unterdiagnostizierten Depressionsform

    Directory of Open Access Journals (Sweden)

    Pezawas L

    2001-01-01

    Full Text Available Die "rezidivierende kurze depressive Störung" (RKD ist durch wenige Tage andauernde und etwa monatlich rezidivierende depressive Episoden charakterisiert, wobei diese mit einem Suizidrisiko ähnlich dem von "klassischen" depressiven Episoden (DE assoziiert sind. Das gemeinsame Vorliegen einer RKD und von DE wird als "kombinierte Depression" (KD bezeichnet und erhöht dieses Risiko noch weiter. RKD-Patienten werden in der allgemeinmedizinischen Versorgung gegenwärtig noch kaum erkannt. Die diagnostischen Kriterien der RKD finden sich im ICD-10 und sind für den klinischen Gebrauch und die Forschung gut geeignet. Die Differentialdiagnose stellt sich vor allem gegen andere kurzdauernde psychiatrische Störungen. Die prospektive Bestätigung der Diagnose und die Evaluation des Therapieerfolges einer prophylaktischen antidepressiven Intervention bei einer RKD unterscheidet sich wesentlich von der DE und ähnelt formal vielmehr dem klinischen Vorgehen wie es bei der Behandlung von Migräne oder Epilepsie üblich ist. Der formal unterschiedliche Verlauf von RKD und einer DE hat zur Folge, daß unterschiedliche Methoden in der Durchführung von Therapiestudien angewendet werden müssen. Die fehlende Berücksichtigung dieser speziellen methodischen Aspekte in RKD-Therapiestudien und der Einschluß von hoch selektierten Patientenstichproben haben vermutlich zu falsch negativen Studienergebnissen in der Vergangenheit geführt. Obwohl einige Autoren über eine erfolgreiche Therapie der RKD bei derzeit etwa 70 Fällen berichten, ist gegenwärtig daraus noch kein eindeutiger therapeutischer Algorithmus ableitbar. Zukünftige kontrollierte Studien ohne die Mängel der Vergangenheit sind daher dringend nötig.

  18. Assoziation einer HIV-Infektion mit ausgewählten Hauterkrankungen unter besonderer Berücksichtigung des Immunstatus

    OpenAIRE

    2013-01-01

    Ziele: I. Prävalenzermittlung spezifischer Hauterkrankungen bei HIV-Patienten. II. Zusammenhänge zwischen der Immunsuppression u. dem Auftreten einer atopischen bzw. seborrhoischen Dermatitis sowie der Psoriasis. III. Klinische Bedeutung der Xerosis cutis, eines Pruritus u. des Gesamt-IgEs. Methoden: Bei 196 HIV-Patienten kamen neben der klinischen Inspektion u. der Erfassung laborchemischer Parameter, standardisierte Diagnostik-bzw. Schweregradscores zum Einsatz. Ergebnisse: E...

  19. Analyse der Konnektoren in ausgewählten Lehrwerken und Grammatiken nebst Vorstellung einer didaktischen und methodischen Konzeption

    Directory of Open Access Journals (Sweden)

    Emad El Din Roshdy Siam

    2012-06-01

    Full Text Available Das Ziel dieser Untersuchung ist die Analyse der Darstellung von Konnektoren in ausgewählten Lehrwerken und Grammati- ken des Deutschen sowie die Vorstellung einer didaktischen und methodischen Konzeption für die Vermittlung der Kon- nektoren. Somit gehört die vorliegende Arbeit zur wissen- schaftlichen Lehrwerk- und Grammatikforschung, die ver- sucht, Fragestellungen zu formulieren und zu beantworten, die für die Analyse fremdsprachlicher Lehrwerke und Grammati- ken Bedeutung haben.

  20. Vergleichende Charakterisierung von Synechocystis sp. PCC 6803 Wildtyp und einer Histidin-Kinase(Slr1759)-freien Mutante

    OpenAIRE

    Nodop, Anke

    2005-01-01

    Cyanobakterien sind oxygene photosynthetische Prokaryoten, in denen die Koordination von Respiration, Photosynthese und Kohlenstoff-Metabolismus sehr komplex ist, da diese Vorgänge z.B. um dieselben Elektronen-Carrier konkurrieren (wie z.B. Photosynthese und Respiration) oder miteinander in Verbindung stehen (wie z.B. Kohlenstoff-Aufnahme und die Aktivität der Elektronentransport-Kette). Da aus Escherichia coli bekannt ist, dass Zwei-Komponenten-Systeme (bestehend aus einer Histidin-Kinase un...

  1. Intelligenzbeurteilung mit der Kaufman Assessment Battery for Children (K-ABC): Pilotstudie an einer Stichprobe sprachentwicklungsgestörter Kinder

    OpenAIRE

    Artner, K.; Barthlen-Weis, M.; Offenberg, M.

    1989-01-01

    29 sprachentwicklungsgestörte Kinder zwischen 7;4 und 11; 11 Jahren, die sich in Behandlung auf einer kinderpsychiatrischen Station befanden, wurden mit der Kaufman Assessment Battery for Children, einem neuen Test zur Intelligenzbeurteilung, der demnächst im deutschen Sprachraum zur Verfügung stehen wird, untersucht. An Hand von Korrelationen wurden die Testergebnisse dieser Kinder mit Daten aus HAWIK-R, AID und Raven verglichen; des weiteren wurde geprüft, ob ein Leistungsunterschied zwisch...

  2. Regionale Unterschiede in der ambulanten Versorgung: Ausmaß, Ursachen und Reformbedarf einer fehlenden Bedarfsgerechtigkeit der Ärzteverteilung

    OpenAIRE

    Ozegowski, Susanne

    2013-01-01

    Die Gewährleistung einer "bedarfsgerechten und gleichmäßigen Versorgung" (§ 70 Abs. 1 SGB V) ist Zielsetzung und Auftrag an die Akteure des deutschen Gesundheitssystems. An dieser normativen Grundlage muss sich im besonderen Maße die ambulante Versorgung messen lassen, die als erster Kontaktpunkt des Patienten mit dem Gesundheitssystem einen wohnortnahen Zugang zur gesundheitlichen Versorgung bieten sollte. Ziel dieser Arbeit ist es daher, das Ausmaß regionaler, nicht bedarfsgerechter Untersc...

  3. Religion und Religionsunterricht in einer pluralen Gesellschaft. Empirische Perspektiven, entwickelt und kommentiert aus protestantischer Perspektive.

    Directory of Open Access Journals (Sweden)

    Hans-Günter Heimbrock

    2014-07-01

    Full Text Available ENGLISH: Sociology of religion assumes that the gap between personal believing and people`s belonging to religious groups in contemporary European societies is still growing. At the same time theologians often summon the idea of an overall decline of personal truth convictions anyhow. The article evaluates the empirical data from selected German schools looking for teacher`s personal adoption of religious orientation in subject-related ways. It evaluates the interplay between personal position-taking of teachers, their classroom practice and its constitutive factors (pupils, contexts of school and schooling etc.. DEUTSCH: Wie gehen Religionslehrkräfte an öffentlichen Schulen unter Bedingungen gesellschaftlicher Pluralisierung mit der eigenen religiösen Position um? Passt die Bezugnahme auf die eigene Glaubensüberzeugung noch in die Gegenwart? Der Beitrag skizziert Problemhorizonte dieser Frage, umreißt zentrale religionspädagogische Herausforderungen und entwickelt Antworten auf der Basis einer regionalen empirischen Untersuchung. Daraus ergibt sich eine neue Perspektive für den Konfessionsbezug des Religionsunterrichts.

  4. Empirische Sozialforschung im Internet. Befunde einer Onlinebefragung zu Inhalten und Erwartungen in der anonymen Beratung

    Directory of Open Access Journals (Sweden)

    Hans-Joachim Gehrmann

    2008-04-01

    Full Text Available Mit der Darstellung und vergleichenden Interpretation von Daten aus einer 2007 durchgeführten Onlinebefragung soll ein Beitrag zur empirischen Fundierung der Arbeit in der Onlineberatung geliefert werden. Vorbereitet wurde die Untersuchung inkl. des einzusetzenden Fragebogens innerhalb eines Lehrforschungsprojekts am Fachbereich "Gesellschaftswissenschaften und Soziale Arbeit" der Hochschule Darmstadt. Wesentliches Ziel dieser Praxisforschung war es, Erwartungen und Bewertungen der Nutzer zur E-Mailberatung der "Helpline" des Caritasverbandes Mainz - zugleich ein Angebot der Beratungsplattform "das-beratungsnetz" - zu ermitteln. Die differenzierte Auswertung der Antworten von insgesamt 140 BefragungsteilnehmerInnen zeigt nicht nur alters-, geschlechts- oder themenspezifische Unterschiede bei der Nachfrage und Bewertung der Beratungsangebote auf, sondern verdeutlicht auch die Notwendigkeit, in der Onlineberatung noch genauer zwischen Informations- und Beratungsbedürfnissen unterscheiden zu müssen und weist neben verschiedenen Kritikpunkten die insgesamt hohe Akzeptanz der Onlineberatung nach. In einem weiteren Schritt werden diese Befunde mit anderen Untersuchungen zur Onlineberatung und zum Internetverhalten verglichen. Dabei werden wichtige Struktur- und Entwicklungsmuster für die Beratungspraxis aufgezeigt und auch der noch bestehende Forschungsbedarf in diesem Feld der Sozialen Dienste skizziert. Abschließende Hinweise zur Wahrung der Anonymität in der Forschungs- und Beratungspraxis und zur Notwendigkeit eines Forschungsverbundes in der Onlineberatung zeigen Wege auf, wie der E-Mail-/Onlineberatung geholfen werden kann, ihr Angebot erfolgreich klientInnenorientiert weiterzuentwickeln.

  5. Medienbildung – ein Unterrichtsprinzip mit Mehrwert. - Versuch einer Annäherung.

    Directory of Open Access Journals (Sweden)

    Susanne Krucsay

    2010-06-01

    Full Text Available Unterrichtsprinzipien sind ‚zahnlose Tiger’, meinte vor einigen Jahren Rudolf Scholten, Bundesminister für Unterricht und Kunst. Wenn auch negativ, immerhin klarer als so manche Erklärungen, die die Komplexität von Unterrichtsprinzipien einzufangen versuchen. Mehr als ein Jahrzehnt ist seitdem vergangen, ob sich am Wahrheitsgehalt dieser Feststellung etwas geändert habe, sei der Beurteilung der Leserinnen und Leser überlassen, die die im österreichischen Lehrplan aufgezählten Unterrichtsprinzipien zumindest dem Namen nach kennen. Gemeinsam ist zunächst den Unterrichtsprinzipien, dass sie Querschnittsmaterien sind und daher theoretisch nicht nur in den explizit ihnen zugedachten Schwerpunktgegenständen, sondern in allen Fächern berücksichtigt werden sollen. Ihr Stellenwert in der schulischen Wertehierarchie ist sowohl bei Lehrenden als auch Lernenden gering bis nicht vorhanden. Erst wenn einer Materie aus unterschiedlichen Interessen Wichtigkeit zugestanden wird, erfolgt eine ‚Beförderung’ des Unterrichtsprinzips zum Unterrichtsgegenstand bzw. Bestandteil eines bestehenden Gegenstandes, wie z.B. Politische Bildung. (Zum Thema: Unterrichtsgegenstand oder Unterrichtsprinzip siehe auch http://www.medienimpulse.at/articles/view/189

  6. Design of a propeller turbine with a variable revolution number; Entwicklung einer Propellerturbine mit variabler Drehzahl

    Energy Technology Data Exchange (ETDEWEB)

    Fella, G.; Wierer, C. [Fella GmbH Maschinen- und Apparatebau, Amorbach (Germany); Goede, E.; Batrekhy, S.; Ruprecht, A. [Stuttgart Univ. (Germany). Inst. fuer Stroemungsmechanik und Hydraulische Stroemungsmaschinen

    1997-12-31

    The small hydroelectric power station of Rupboden in the Oberfranken district was reactivated after having been decommissioned for 30 years. This new low pressure plant consists of an open-flume turbine with an adjustable diffusor and a firm rotor disk (propeller) with a vertical rod. A large range of operation at a constant height of fall is ensured by a variable revolution number. The profiles of the adjustable diffusor and rotor disk and the design of the draft tube were optimized using numerical flow calculation. First operating experience is very positive. The turbine runs extremely smoothly over the entire range. (orig.) [Deutsch] Das Kleinwasserkraftwerk Rupboden in Oberfanken wurde nach 30 Jahren Stillstand reaktiviert. Die neue Niederdruckanlage besteht aus einer Schachtturbine mit verstellbarem Leitapparat, feststehendem Laufrad (Propeller) mit senkrechter Welle. Zum Erzielen eines grossen Betriebsbereiches bei gleichbleibender Fallhoehe wurde eine variable Drehzahl vorgesehen. Die Profilierung von Leitapparat und Laufrad sowie die Formgebung fuer das Saugrohr wurden mit numerischer Stroemungsberechnung optimiert. Erste Betriebserfahrungen sind sehr positiv. Die Turbine laeuft im gesamten Leistungsbereich ausserordentlich ruhig. (orig.)

  7. Thermoeconomic analysis of a bioenergetic plant; Thermooekonomische Analyse einer Bioenergie-Anlage

    Energy Technology Data Exchange (ETDEWEB)

    Hebecker, D.; Bittrich, P. [Martin-Luther-Univ. Halle (Germany). Fachbereich Ingenieurwissenschaften

    2003-07-01

    The thermoeconomical analysis allows to include - besides market-based expenditures and prices - the natural required energetic effort for manufacturing a product into evaluation. Exergy is the suitable property to describe these natural required expenditures. The efficiency of processes can be characterized by deviations from this minimum effort. The use of exergetic costing makes it possible to compare products with different qualities, e.g. energy carrier, heat, cold, electric current by including the manufacturing process. This is presented for a biomass utilization plant. [German] Die thermooekonomische Analyse bezieht neben Kosten und Preisen auch den naturgesetzlich notwendigen energetischen Aufwand fuer die Herstellung eines Produktes in die Bewertung ein. Ein geeignetes Mass fuer diesen Aufwand ist die Exergie. Mit ihr kann die Guete eines Produktionsverfahrens - gekennzeichnet durch die Abweichung vom energetischen Mindestaufwand - quantifiziert werden. Mit einem exergetischen Kostenansatz koennen Produkte unterschiedlicher Qualitaet, wie zum Beispiel Energietraeger, Waerme, Kaelte oder Strom, unter Einbeziehung des Herstellungsverfahrens miteinander verglichen werden. Dies wird am Beispiel einer Bioenergie-Anlage aufgezeigt.

  8. Safety strategy for a hydrogen-based energy economy; Sicherheitstechnische Begleitung einer zukuenftigen Energieversorgung mit Wasserstoff

    Energy Technology Data Exchange (ETDEWEB)

    Elliger, T. [TUeV SUeD Industrie Service GmbH, Gasanlagen - Wasserstofftechnologie, Muenchen (Germany)

    2008-04-15

    In July 2006, the research project 'icefuel' was started. Eleven project partners cooperate to provide the fundamentals for an energy transport, storage and conversion system based on cryogenic fluids like liquid hydrogen or liquid natural gas. The central element of the icefuel supply system is a stationary cryotank, from which liquid hydrogen is transported to consumers connected to the supply lines. This requires a multifunctional cable with high-efficiency insulation (similar to the offshore cables for parallel transport of fluids, data, and electric power). Currently, the technical details of the icefuel cable are defined and tested in an experimental miniplant. First results are expected for mid-2008. (orig.) [German] Im Juli 2006 startete das Forschungsprojekt 'icefuel', mit dem die elf beteiligten Projektpartner die Grundlagen fuer den Aufbau eines Energietransport-, Speicherungs- und Wandlungssystems basierend auf kryogenen Medien wie fluessigem Wasserstoff bzw. fluessigem Erdgas zu schaffen. An zentraler Stelle im icefuel-Versorgungssystem befindet sich eine stationaerer Kryobehaelter, in dem der zuvor verfluessigte Wasserstoff vorgehalten wird. Von diesm lokalen Speicher wird der Wasserstoff zu den jeweiligen Verbrauchern geleitet, die ueber abzweigende Versorgungsleitungen an die Hauptleitungen angeschlossen sind. Damit dieses System funktioniert ist ein spezielles Multifunktionskabel mit hoher Isolationswirkung noetig (aehnlich wie die Multifunktionskabel in der Offshore-Technologie zum parallelen Transport von Medien, Daten und Strom). Im Rahmen des Projekts werden zur Zeit die technischen Details des icefuel-Kabels festgelegt und in einer ersten Versuchsanlage (Miniplant) erprobt. Der aktuelle Zeitplan sieht erste Ergebnisse fuer den Sommer 2008 vor.

  9. Marketing for green building; Marketing fuer oekologisches Bauen. Ergebnisse einer Studie zum SynergieHaus-Projekt

    Energy Technology Data Exchange (ETDEWEB)

    Winkler, S.; Niedergesaess, U. [imug Beratungsgesellschaft mbH, Hannover (Germany)

    2001-03-12

    Ecological or green building becomes increasingly relevant in Germany. Of specific concern are the following questions that are considered more closely in the following article: Who are the customers or builder-owners of low energy houses? How to involve and motivate potential customers for this environmental form of building? What are the central motives in buying or building low energy houses and how to address private households with the issue of ecological building and living? These questions are discussed with reference to the results of a study carried out in the context of a specific green building sponsoring project named ''SynergieHaus''. (orig./CB) [German] Oekologisches Bauen gewinnt in Deutschland zunehmend an Bedeutung. Wer aber sind die Kaeufer bzw. Bauherren von Niedrigenergiehaeusern? Wie koennen Bauinteressenten fuer diese umweltorientierte Form des Bauens begeistert und gewonnen werden? Welches sind die zentralen Motive fuer den Kauf eines Niedrigenergiehauses bzw. wie koennen private Haushalte fuer oekologisches Bauen und Wohnen angesprochen werden? Diese marketingrelevanten Fragen werden in dem Beitrag naeher betrachtet anhand von Ergebnissen einer Studie zum SynergieHaus-Projekt. (orig./CB)

  10. Medienbildung als konstruktive Aneignung von Medienensembles. Vorbemerkungen zu einer Theorie der Medienpädagogik

    Directory of Open Access Journals (Sweden)

    Tilman Bechthold-Hengelhaupt

    2016-12-01

    Full Text Available Die These dieses Aufsatzes lautet, dass im medienpädagogischen Handeln und Kommunizieren Erfahrungen mit dinglich gegebenen Medien verarbeitet und dass dadurch Medienensembles konstruiert werden, also praktisch verfügbare Konfigurationen von Geräten und Gegenständen, unter denen die beteiligten Akteure eine Auswahl treffen können. Der Begriff der Wahl lässt insbesondere einen Anschluss an die Idee einer demokratischen Medienbildung zu. Als erkenntnistheoretische Grundlage wird eine Orientierung an der sinnlichen Erfahrung vorgeschlagen, die gerade in Immanuel Kants "Kritik der reinen Vernunft" als Erkenntnisquelle begründet wird. Dass der Begriff der Medienensembles auch die historische Dimension aufschließen kann, wird am Beispiel des so genannten Neumagener Schulreliefs gezeigt, einem archäologischen Dokument aus der Zeit um 180 n.Chr. This essay proposes the thesis that media education should be understood as consisting in negotiations about experiences with media ensembles. In a constructivist approach, the acting with media ensembles is seen as a form of coming to terms with devices and other media objects that are accessible via sensory experience. In this context, a pivotal idea is that choices are made between different media that are at hand for educational purposes. This concept is further elaborated in the concepts of Immanuel Kant's theory of perception. As an example, an archaeological monument from ca. 180 AD ("Neumagener Schulrelief" is described and interpreted.

  11. Scenarios of a deregulated electricity industry. Analysis; Szenarien einer liberalisierten Stromversorgung. Analyse

    Energy Technology Data Exchange (ETDEWEB)

    Foerster, G.

    2002-07-01

    Four scenarios have been established which represent the spectrum of probable developments in the Internal Market until 2010. The content-related postulations are described in two parts. In the first part, various fundamental settings are defined which apply to all four scenarios alike, whereas in the second part a set of influencing variables (descriptors) are defined which develop along dissimilar, distinctive lines and thus can be used for modelling within the four different scenarios. Applying a special scenario analysing method, the cross-impact method, those combinations of descriptors can be derived which lead to conclusive scenarios and consistent postulations. (orig./CB) [German] Es wurden vier Szenarien erarbeitet, die das Spektrum der wahrscheinlichen Entwicklungen im EU-Binnenmarkt bis zum Jahr 2010 repraesentieren. Die inhaltlichen Aussagen werden in zwei Teilen beschrieben. Der erste Teil beinhaltet eine Reihe von Rahmengroessen, die fuer alle vier Szenarien gleich sind. Der zweite Teil besteht aus einem Satz von Einflussgroessen (Deskriptoren) mit verschiedenen Auspraegungen, in denen sich die vier Szenarien unterscheiden. Mit Hilfe einer speziellen Szenariotechnik, der Cross-Impact-Methode, bestimmt man diejenigen Kombinationen der Deskriptorauspraegungen, die zu in sich schluessigen Szenarien ohne widerspruechliche Assagen fuehren. (orig./CB)

  12. Pressure shock analyses in a power plant cooling system and a hydraulic stowing system in a potassium mine; Druckstossanalysen am Beispiel eines Kraftwerkskuehlsystems und einer Spuelversatzanlage im Kalibergbau

    Energy Technology Data Exchange (ETDEWEB)

    Lange, H. [Babcock Borsig Power Service GmbH, Oberhausen (Germany)

    2000-07-01

    Pressure shocks in pipeline systems are caused by acceleration or delaying of fluid flow. They depend on the acceleration or delay rate, the medium density, and the local sound velocity with which the pressure waves propagate. Pressure shocks cause dynamic external loads which may cause damage to pipes, connections or supports and should therefore precalculated already in the planning stage in order to prevent damage. The contribution shows how precalculation of the flow data in a complex, meshed pipeline system will help to optimize the sytem and to maintain its integrity in case of pressure shocks. [German] Druckstoesse in Leitungssystemen werden erzeugt, wenn ein Fluid beschleunigt oder abgebremst (verzoegert wird). Die Groesse dieser Druckstoesse haengt von der Verzoegerung (Beschleunigung) deren Mediumsdichte sowie von der oertlichen Schallgeschwindigkeit ab mit der sich diese Druckwellen fortpflanzen. Druckstoesse bewirken nicht nur eine kurzzeitige Druckaenderung im System, sondern erzeugen dynamische aeussere Lasten, die erhebliche Groessen annehmen und fuer diverse Schaeden an Leitungen, Anschluessen oder Unterstuetzungen verantwortlich sein koennen. Daher ist die Berechnung im voraus wuenschenswert und notwendig, um schon in der Planung entsprechende konstruktive Massnahmen einfliessen zu lassen, damit keine Ueberbeanspruchung des Systems eintreten kann. In den vorliegenden Analysen wird gezeigt, dass fuer ein komplexes, vermaschtes Rohrleitungssystem mit Rueckschlagklappen und Pumpen bei Pumpenausfall durch Vorausberechnungen der Stroemungsdaten, wie Massenstroeme, Stroemungsgeschwindigkeiten, Druecke usw., fuer verschiedene Lastfaelle eine Systemoptimierung durchgefuehrt werden kann. Ausserdem wird gezeigt, dass durch geeignete Massnahmen bei einer Spuelversatzanlage der Druckstoss so abgemindert werden kann, dass die Integritaet des Systems gewaehrleistet wird. (orig.)

  13. Association between familial atrial fibrillation and risk of new-onset atrial fibrillation

    NARCIS (Netherlands)

    Lubitz, Steven A.; Yin, Xiaoyan; Fontes, Joao D.; Magnani, Jared W.; Rienstra, Michel; Pai, Manju; Villalon, Mark L.; Vasan, Ramachandran S.; Pencina, Michael J.; Levy, Daniel; Larson, Martin G.; Ellinor, Patrick T.; Benjamin, Emelia J.

    2010-01-01

    CONTEXT: Although the heritability of atrial fibrillation (AF) is established, the contribution of familial AF to predicting new-onset AF remains unknown. OBJECTIVE: To determine whether familial occurrence of AF is associated with new-onset AF beyond established risk factors. DESIGN, SETTING, AND

  14. Association between familial atrial fibrillation and risk of new-onset atrial fibrillation

    NARCIS (Netherlands)

    Lubitz, Steven A.; Yin, Xiaoyan; Fontes, Joao D.; Magnani, Jared W.; Rienstra, Michel; Pai, Manju; Villalon, Mark L.; Vasan, Ramachandran S.; Pencina, Michael J.; Levy, Daniel; Larson, Martin G.; Ellinor, Patrick T.; Benjamin, Emelia J.

    2010-01-01

    CONTEXT: Although the heritability of atrial fibrillation (AF) is established, the contribution of familial AF to predicting new-onset AF remains unknown. OBJECTIVE: To determine whether familial occurrence of AF is associated with new-onset AF beyond established risk factors. DESIGN, SETTING, AND P

  15. Does Myocardial Infarction Beget Atrial Fibrillation and Atrial Fibrillation Beget Myocardial Infarction?

    NARCIS (Netherlands)

    Vermond, Rob A.; Van Gelder, Isabelle C.; Crijns, Harry J.; Rienstra, Michiel

    2015-01-01

    Atrial fibrillation (AF) affects millions of people worldwide.(1) It is already known several decades that AF is not a benign condition, and it's associated with a 5-fold increased risk of stroke, 3-fold increased risk of heart failure, and doubling of risk of dementia and death.(2-4) Myocardial

  16. Ethnic Differences in Atrial Fibrillation Identified Using Implanted Cardiac Devices

    NARCIS (Netherlands)

    Lau, Chu-Pak; Gbadebo, T. David; Connolly, Stuart J.; Van Gelder, Isabelle C.; Capucci, Alessandro; Gold, Michael R.; Israel, Carsten W.; Morillo, Carlos A.; Siu, Chung-Wah; Abe, Haruhiko; Carlson, Mark; Tse, Hung-Fat; Hohnloser, Stefan H.; Healey, Jeff S.

    2013-01-01

    Ethnic Difference in Atrial Fibrillation Incidence.Introduction: Atrial fibrillation (AF) is suggested to be less common among black and Asian individuals, which could reflect bias in symptom reporting and access to care. In the Asymptomatic AF and Stroke Evaluation in Pacemaker Patients and the AF

  17. Dronedarone in high-risk permanent atrial fibrillation

    DEFF Research Database (Denmark)

    Connolly, Stuart J; Camm, A John; Halperin, Jonathan L;

    2011-01-01

    Dronedarone restores sinus rhythm and reduces hospitalization or death in intermittent atrial fibrillation. It also lowers heart rate and blood pressure and has antiadrenergic and potential ventricular antiarrhythmic effects. We hypothesized that dronedarone would reduce major vascular events...... in high-risk permanent atrial fibrillation....

  18. Rising rates of hospital admissions for atrial fibrillation

    DEFF Research Database (Denmark)

    Friberg, Jens; Buch, Nina Pernille Gardshodn; Scharling, Henrik;

    2003-01-01

    Atrial fibrillation is a common arrhythmia associated with excess morbidity and mortality. We studied temporal changes in hospital admission rates for atrial fibrillation using data from a prospective population-based cohort study spanning 2 decades (the Copenhagen City Heart Study)....

  19. Atrial fibrillation: Is ablation the way of the future?

    Institute of Scientific and Technical Information of China (English)

    Brian Olshansky

    2004-01-01

    @@ This issue of the Journal of Geriatric Cardiology features a manuscript entitled "A three-pulmonary vein isolation approach to treat paroxysmal atrial fibrillation".Dr. Lexin Wang addresses an important issue, and is to be congratulated for taking a new look at an approach to ablate atrial fibrillation.

  20. The immediate future for the medical treatment of atrial fibrillation

    DEFF Research Database (Denmark)

    Pedersen, Ole Dyg; Brendorp, Bente; Køber, Lars;

    2002-01-01

    Atrial fibrillation is the most commonly sustained cardiac arrhythmia and a common reason for mortality and morbidity. Atrial fibrillation causes disease for three reasons: i) the ventricular rate is often high, which leads to symptoms ranging from discomfort to life threatening heart failure; ii...

  1. Vascular disease and stroke risk in atrial fibrillation

    DEFF Research Database (Denmark)

    Olesen, Jonas Bjerring; Lip, Gregory Y.H.; Lane, Deirdre A

    2012-01-01

    Vascular disease (including myocardial infarction and peripheral artery disease) has been proposed as a less well-validated risk factor for stroke in patients with atrial fibrillation. We investigated whether vascular disease is an independent risk factor of stroke/thromboembolism in atrial...... fibrillation and whether adding vascular disease improves Congestive heart failure, Hypertension, Age 75 years, Diabetes, previous Stroke (CHADS(2)) risk stratification....

  2. Radiofrequency ablation as initial therapy in paroxysmal atrial fibrillation

    DEFF Research Database (Denmark)

    Cosedis Nielsen, Jens; Johannessen, Arne; Raatikainen, Pekka;

    2012-01-01

    There are limited data comparing radiofrequency catheter ablation with antiarrhythmic drug therapy as first-line treatment in patients with paroxysmal atrial fibrillation.......There are limited data comparing radiofrequency catheter ablation with antiarrhythmic drug therapy as first-line treatment in patients with paroxysmal atrial fibrillation....

  3. Atrial fibrillation: a new look at an old arrhythmia

    NARCIS (Netherlands)

    Meijler, F.L.

    1983-01-01

    The ventricular rhythm during atrial fibrillation in human beings is random because the excitatory process of atrial fibrillation itself is almost certainly a random phenomenon. It remains random because A V junctional memory is too short to inftuence the sequence of conducted impulses . In human be

  4. Effect of Stirring and Seeding on Whey Protein Fibril Formation

    NARCIS (Netherlands)

    Bolder, S.G.; Sagis, L.M.C.; Venema, P.; Linden, van der E.

    2007-01-01

    The effect of stirring and seeding on the formation of fibrils in whey protein isolate (WPI) solutions was studied. More fibrils of a similar length are formed when WPI is stirred during heating at pH 2 and 80 C compared to samples that were heated at rest. Addition of seeds did not show an addition

  5. Atrial fibrillation and bleeding complication - risk factors and risk marker

    NARCIS (Netherlands)

    Breithardt, G.; Ravens, U.; Kirchhof, P.; van Gelder, I. C.

    2012-01-01

    The development of atrial fibrillation (AF) is closely linked to risk factors like hypertension and heart failure, diabetes mellitus, myocardial infarction and valvular heart disease. These factors partly overlap with those which determine the progression of atrial fibrillation and the incidence of

  6. Destroying activity of magnetoferritin on lysozyme amyloid fibrils

    Energy Technology Data Exchange (ETDEWEB)

    Kopcansky, Peter; Siposova, Katarina [Institute of Experimental Physics, SAS, Watsonova 47, 040 01 Kosice (Slovakia); Melnikova, Lucia, E-mail: melnikova@saske.sk [Institute of Experimental Physics, SAS, Watsonova 47, 040 01 Kosice (Slovakia); Bednarikova, Zuzana [Institute of Experimental Physics, SAS, Watsonova 47, 040 01 Kosice (Slovakia); Institute of Chemical Sciences, Faculty of Sciences, Safarik University, Kosice (Slovakia); Timko, Milan; Mitroova, Zuzana; Antosova, Andrea [Institute of Experimental Physics, SAS, Watsonova 47, 040 01 Kosice (Slovakia); Garamus, Vasil M. [Helmholtz-Zentrum Geesthacht: Centre for Materials and Coastal Research, Max-Planck-Street 1, 21502 Geesthacht (Germany); Petrenko, Viktor I. [Joint Institute for Nuclear Research, Joliot-Curie 6, Dubna, 141980 Moscow Region (Russian Federation); Kyiv Taras Shevchenko National University, Volodymyrska Street 64, Kyiv 01033 (Ukraine); Avdeev, Mikhail V. [Joint Institute for Nuclear Research, Joliot-Curie 6, Dubna, 141980 Moscow Region (Russian Federation); Gazova, Zuzana [Institute of Experimental Physics, SAS, Watsonova 47, 040 01 Kosice (Slovakia); Department of Medical and Clinical Biochemistry and LABMED, Tr. SNP 1, 040 11 Kosice (Slovakia)

    2015-03-01

    Presence of protein amyloid aggregates (oligomers, protofilaments, fibrils) is associated with many diseases as diabetes mellitus or Alzheimer's disease. The interaction between lysozyme amyloid fibrils and magnetoferritin loaded with different amount of iron atoms (168 or 532 atoms) has been investigated by small-angle X-rays scattering and thioflavin T fluorescence measurements. Results suggest that magnetoferritin caused an iron atom-concentration dependent reduction of lysozyme fibril size. - Highlights: • The interaction between lysozyme amyloid fibrils and magnetoferritin loaded with different amount of iron atoms (168 or 532 atoms) has been investigated by small-angle X-rays scattering and thioflavin T fluorescence measurements. • Results suggest that magnetoferritin caused an iron atom-concentration dependent reduction of lysozyme fibril size.

  7. Genetics of Atrial Fibrillation and Possible Implications for Ischemic Stroke

    Directory of Open Access Journals (Sweden)

    Robin Lemmens

    2011-01-01

    Full Text Available Atrial fibrillation is the most common cardiac arrhythmia mainly caused by valvular, ischemic, hypertensive, and myopathic heart disease. Atrial fibrillation can occur in families suggesting a genetic background especially in younger subjects. Additionally recent studies have identified common genetic variants to be associated with atrial fibrillation in the general population. This cardiac arrhythmia has important public health implications because of its main complications: congestive heart failure and ischemic stroke. Since atrial fibrillation can result in ischemic stroke, one might assume that genetic determinants of this cardiac arrhythmia are also implicated in cerebrovascular disease. Ischemic stroke is a multifactorial, complex disease where multiple environmental and genetic factors interact. Whether genetic variants associated with a risk factor for ischemic stroke also increase the risk of a particular vascular endpoint still needs to be confirmed in many cases. Here we review the current knowledge on the genetic background of atrial fibrillation and the consequences for cerebrovascular disease.

  8. NASA's First Atrial Fibrillation Case - Deke Slayton

    Science.gov (United States)

    Tarver, William J.

    2010-01-01

    Concerns about heart dysrhythmia have been present since the earliest days of the US manned space program. While information about an astronaut's health is general kept private, one of the original seven American astronaut's health status was played out in a very public forum. Donald "Deke" Slayton was removed from the second manned space flight when it was discovered he had idiopathic atrial fibrillation. Referencing the original medical documents, details of how this was discovered and managed from the medical perspective will be reviewed. This is NASA's first heart dysrhythmia case in an astronaut and it proves quite interesting when placed in historic perspective.

  9. Atrial fibrillation in China: a brief review

    Institute of Scientific and Technical Information of China (English)

    MA Chang-sheng; DU Xin; JIANG Chen-xi

    2009-01-01

    @@ Atrial fibrillation (AF) is the most common heart rhythm disturbance encountered in clinical practice.It affects at least ten million Chinese, constituting a major public health epidemic. For the shortness of resource in the initial stage of new China and the chaos during the culture revolution, there was a scarcity of AF data on the Chinese population. However, Chinese physicians had never stopped exploring in this field, which has provided a solid foundation for today's flourishing development in the research of AF. This paper aims to review the major achievements in dealing with AF in the past 60 years in China, especially in the latest 15 years.

  10. Current approaches in atrial fibrillation treatment

    Directory of Open Access Journals (Sweden)

    Cenk Sarı

    2014-09-01

    Full Text Available Atrial fibrillation (AF is the most common sustained arrhythmia encountered in clinical practice. Its incidence increases with age. AF is classified into subtypes according to the duration and/or able to provide sinus rhytym. İnitially, patients should be evaluated for rhythm or rate control for appropriate treatment. Second stage of strategy aimed to investigate the feasibility of anticoagulation therapy. Recently, due to the progress made in treatment with rhythm control and anticoagulation therapy, either American or European guidelines have been renovated. These developments have taken place in the newly published guide. In this article, the current change in the management of AF is discussed.

  11. Association between Familial Atrial Fibrillation and Risk of New-onset Atrial Fibrillation

    Science.gov (United States)

    Lubitz, Steven A.; Yin, Xiaoyan; Fontes, João D.; Magnani, Jared W.; Rienstra, Michiel; Pai, Manju; Villalon, Mark L.; Vasan, Ramachandran S.; Pencina, Michael J.; Levy, Daniel; Larson, Martin G.; Ellinor, Patrick T.; Benjamin, Emelia J.

    2011-01-01

    Context Although the heritability of atrial fibrillation (AF) is established, the contribution of familial AF to predicting new-onset AF remains unknown. Objective To determine whether familial occurrence of AF is associated with new-onset AF beyond established risk factors. Design, Setting, and Participants The Framingham Heart Study, a prospective population-based cohort study started in 1948. Original and Offspring Cohort participants were age at least 30 years, free of AF at the baseline examination, and had at least one parent or sibling enrolled in the study. Main outcome measures The incremental predictive value of incorporating different features of familial AF (any familial AF, premature familial AF [onset ≤65 years], number of affected relatives, and youngest age of onset in a relative) into a risk model for new-onset AF. Results Of 4421 participants (11971 person-examinations, mean age 54±13 years, 54% women), 440 developed AF during follow-up. Familial AF occurred in 1185 participants (26.8%) and premature familial AF occurred in 351 (7.9%) participants. AF occurred more frequently among participants with familial AF than without familial AF (unadjusted absolute event rates of 5.8% and 3.1%, respectively). The association was not attenuated by adjustment for AF risk factors (multivariable-adjusted HR 1.40, 95% CI 1.13–1.74) or reported AF-related genetic variants. Among the different features of familial AF examined, premature familial AF was associated with improved discrimination beyond traditional risk factors to the greatest extent (c-statistic 0.842; 95% CI, 0.826–0.858 to 0.846; 95%CI, 0.831–0.862; P=.004). Modest changes in integrated discrimination improvement were observed with premature familial AF (2.1%). Net reclassification improvement (assessed using eight-year risk thresholds of 10%) did not change significantly with premature familial AF (0.011; 95% CI, −0.021–0.042; P=.51), although category-less net reclassification was

  12. Consequences of national and international law for incinerator operation: The Rugenberger Damm incinerator; Der Betrieb einer modernen Muellverbrennungsanlage im Nebel nationaler und europaeischer Gesetzgebung, aufgezeigt am Beispiel der Muellverbrennungsanlage Rugenberger Damm

    Energy Technology Data Exchange (ETDEWEB)

    Menke, D.; Zwahr, H. [MVR Muellverwertungsanlage Rugenberger Damm GmbH und Co. KG, Hamburg (Germany)

    2000-07-01

    According to the author, national and international law pose too many restrictions on incinerator operation and make it impossible to integrate new scientific findings. [German] Der Betrieb einer Muellverbrennungsanlage im Nebel nationaler und europaeischer Gesetzgebung ist nur moeglich, wenn in Form von Anlagenkonzeption und gutem juristischem Beistandein gutes ''Radar'' zur Verfuegung steht, um alle Hindernisse in ausreichendem Abstand sicher zu Umschiffen. Die deutsche und europaeische Gesetzgebung ist viel zu kompliziert. Im Versuch, alles perfekt und bis ins Kleinste detalliert zu regeln, werden die Gesetze immer unuebersichtlicher. Schlupfloecher sind dennoch oder gerade deshalb ausreichend vorhanden. Die Grenzen juristischer Spitzfindigkeiten sind noch lange nicht erreicht, da auch die massgeblichen Politiker selten Juristen sind. Dem technischen Fortschritt und dem Einsatz neuer wissenschaftlicher Erkenntnisse wird durch Vorgabe technischer Rahmenbedingungen in Gesetzen ein Riegel vorgeschoben, der nur schwer wieder zu beseitigen ist.

  13. The contrasting effect of macromolecular crowding on amyloid fibril formation.

    Directory of Open Access Journals (Sweden)

    Qian Ma

    Full Text Available BACKGROUND: Amyloid fibrils associated with neurodegenerative diseases can be considered biologically relevant failures of cellular quality control mechanisms. It is known that in vivo human Tau protein, human prion protein, and human copper, zinc superoxide dismutase (SOD1 have the tendency to form fibril deposits in a variety of tissues and they are associated with different neurodegenerative diseases, while rabbit prion protein and hen egg white lysozyme do not readily form fibrils and are unlikely to cause neurodegenerative diseases. In this study, we have investigated the contrasting effect of macromolecular crowding on fibril formation of different proteins. METHODOLOGY/PRINCIPAL FINDINGS: As revealed by assays based on thioflavin T binding and turbidity, human Tau fragments, when phosphorylated by glycogen synthase kinase-3β, do not form filaments in the absence of a crowding agent but do form fibrils in the presence of a crowding agent, and the presence of a strong crowding agent dramatically promotes amyloid fibril formation of human prion protein and its two pathogenic mutants E196K and D178N. Such an enhancing effect of macromolecular crowding on fibril formation is also observed for a pathological human SOD1 mutant A4V. On the other hand, rabbit prion protein and hen lysozyme do not form amyloid fibrils when a crowding agent at 300 g/l is used but do form fibrils in the absence of a crowding agent. Furthermore, aggregation of these two proteins is remarkably inhibited by Ficoll 70 and dextran 70 at 200 g/l. CONCLUSIONS/SIGNIFICANCE: We suggest that proteins associated with neurodegenerative diseases are more likely to form amyloid fibrils under crowded conditions than in dilute solutions. By contrast, some of the proteins that are not neurodegenerative disease-associated are unlikely to misfold in crowded physiological environments. A possible explanation for the contrasting effect of macromolecular crowding on these two sets of

  14. Ultrastructural organization of amyloid fibrils by atomic force microscopy.

    Science.gov (United States)

    Chamberlain, A K; MacPhee, C E; Zurdo, J; Morozova-Roche, L A; Hill, H A; Dobson, C M; Davis, J J

    2000-12-01

    Atomic force microscopy has been employed to investigate the structural organization of amyloid fibrils produced in vitro from three very different polypeptide sequences. The systems investigated are a 10-residue peptide derived from the sequence of transthyretin, the 90-residue SH3 domain of bovine phosphatidylinositol-3'-kinase, and human wild-type lysozyme, a 130-residue protein containing four disulfide bridges. The results demonstrate distinct similarities between the structures formed by the different classes of fibrils despite the contrasting nature of the polypeptide species involved. SH3 and lysozyme fibrils consist typically of four protofilaments, exhibiting a left-handed twist along the fibril axis. The substructure of TTR(10-19) fibrils is not resolved by atomic force microscopy and their uniform appearance is suggestive of a regular self-association of very thin filaments. We propose that the exact number and orientation of protofilaments within amyloid fibrils is dictated by packing of the regions of the polypeptide chains that are not directly involved in formation of the cross-beta core of the fibrils. The results obtained for these proteins, none of which is directly associated with any human disease, are closely similar to those of disease-related amyloid fibrils, supporting the concept that amyloid is a generic structure of polypeptide chains. The detailed architecture of an individual fibril, however, depends on the manner in which the protofilaments assemble into the fibrillar structure, which in turn is dependent on the sequence of the polypeptide and the conditions under which the fibril is formed.

  15. Physical properties of a wound-probe-system; Physikalische Parameter einer Gamma-Wundsonde

    Energy Technology Data Exchange (ETDEWEB)

    Koenig, F.; Ogris, E.; Weidlich, G. [Donauspital Wien (Austria). Abt. fuer Nuklearmedizinische Diagnostik und Therapie; Lauer, D.; Aiginger, H. [Atominstitut der Oesterreichischen Universitaeten, Vienna (Austria)

    1998-12-31

    In our department a probe-system was purchased, for the detection of wound contamination. The probe utilizes a CdTe-detector with a diameter of 8 mm. Countrate is displayed by a ratemeter. This paper describes the efficiency of the probe from 30 to 400 keV. Spatial resolution is represented in terms of full width at half maximum: 2.3 cm for a distance of 2 cm. The dependence of geometrical efficiency was measured with Tc-99m and I-131 point sources. Although not equipped with a special collimator, the probe provides good spatial resolution. The overall quality of the system is in the range of a probe designed specially for usage during intraoperative nuclide search. It could be demonstrated during surgery, that the wound-probe fits the need for Lymphoscintigraphy. (orig.) [Deutsch] Am Donauspital wurde fuer die Feststellung von Kontaminationen im Wundbereich eine Gamma-Wundsonde beschafft. Die Sonde verwendet einen CdTe-Detektor mit einem Durchmesser von 8 mm, als Anzeigeinstrument fungiert ein Ratemeter. Neben der Empfindlichkeit im Energiebereich von 30 bis 400 keV wurde das raeumliche Aufloesungsvermoegen (FWHM in 2 cm Abstand: 2,3 cm) und die Abhaengigkeit der Sondenempfindlichkeit von den geometrischen Rahmenbedingungen fuer die Nuklide Tc-99m und I-131 ermittelt. Sowohl in der Ebene parallel zur Koerperoberflaeche als auch in der Ebene senkrecht dazu konnte auch ohne Kollimator eine ausgepraegte Winkelempfindlichkeit bei geringen Distanzen festgestellt werden. Die physikalischen Parameter (Efficiency, Ortsaufloesung und Richtungsempfindlichkeit) des Sondensystems sind nur geringfuegig schlechter, als jene einer speziell fuer den intraoperativen Einsatz konstruierten Sonde. Dies konnte auch bei einem versuchsweisen Einsatz an einem Patienten bestaetigt werden. (orig.)

  16. Sich selbst und den anderen aus einer asymmetrischen Position verstehen – Die Kunst der Unterscheidung

    Directory of Open Access Journals (Sweden)

    Marek Čikel

    2016-12-01

    Full Text Available Sich selbst und den Anderen zu kennen setzt immer eine asymmetrische Position voraus. Die Person ist darauf gestellt, diese Leistung aus einer Position durchzuführen, die keine klare Orientierung ermöglicht und unsere derzeitigen Dispositionen beträchtlich übersteigt. Dem Menschen wird schließlich immer so viel gezeigt, damit er weiß und sieht, aber nicht so klar, damit er auch versteht. Die Art und Weise, in welcher eine Person mit sich selbst, mit dem Zorn, der Frustration, den Leidenschaften, der Sprache umgeht, vermittelt Informationen über individuelle Regungen der Seele, über Bewältigungsmechanismen. Man kann sie für eine gewisse Hilfestellung der Sprache selbst halten. Aber das Verständnis dieser Hilfestellung und des Ratschlags nur im Verhältnis zu sich selbst wäre zu eng. Wir wollen oder bekommen oft Ratschläge, die andere betreffen, aber wir müssen sie „aus sich selbst“ lösen. Und gerade aus sich selbst sollen wir fragen und sprechen. Im Augenblick, wenn diese Tiefe des Sprechens und Hörens erreicht wird, eröffnet sich die Möglichkeit, mit sich selbst und mit dem Anderen zu sein. Es ist jedoch zugleich ein Augenblick des Kampfes, der sich am Hintergrund des Gehörten konstituiert, das am Anfang oft als etwas Unverständliches erscheint oder das durch Vorstellungen und Schmerzen gestört wird. Die Antwort auf diesen Kampf ist die Kunst der Unterscheidung.

  17. Testing and modification of a simple flow turbine; Messtechnische Untersuchung und Modifikation einer einfachen Durchstroemturbine

    Energy Technology Data Exchange (ETDEWEB)

    Gentner, C. [Stuttgart Univ. (Germany). Inst. fuer Stroemungsmechanik und Hydraulische Stroemungsmaschinen; Fischer, G. [SKAT, St. Gallen (Switzerland)

    1997-12-31

    A study conducted at the IHS had the aim to obtain basic information on whether it is possible to build flow turbines following the free jet principle that are on a par with, or superior to, the conventional design, especially in terms of performance and the efficiency curve. Several inflow contours with a ventilated free jet and a conventional flow turbine were studied. The direct comparison of these variants revealed a slightly enhanced peak load efficiency and a very distinct superiority of the free jet contour during partial load. But the efficiency of all variants failed to attain the values claimed by commercial manufacturers. As compared to the initial contour, peak load efficiency was enhanced by 5 per cent. During partial load, the variants studied showed a distinct superiority of the free jet concept over the contour of conventional flow turbines. (orig.) [Deutsch] Am IHS wurde eine Untersuchung mit dem Ziel durchgefuehrt, grundlegende Aussagen zu gewinnen, ob Durchstroemturbinen mit dem Freistrahlprinzip gebaut werden koennen, die dem konventionellen Design, vor allem in bezug auf Leistungsausbeute und Wirkungsgradverlauf, gleichwertig oder ueberlegen sind. Es wurden mehrere Anstroemkonturen mit belueftetem Freistrahl und einer konventionellen Durchstroemturbine untersucht. Der direkte Vergleich der am Institut untersuchten Varianten ergab bei etwas hoeherem Spitzenwirkungsgrad sehr deutliche Vorteile der Freistrahlkontur im Teillastbereich. Das Wirkungsgradniveau aller Varianten lag jedoch unter den Werten, die von kommerziellen Herstellern veroeffentlicht werden. Gegenueber der Ausgangskontur wurde im Spitzenwirkungsgrad eine Verbesserung von 5% erreicht. Im Teillastbereich ergibt sich fuer die hier untersuchten Varianten eine deutliche Ueberlegenheit der Freistrahlkonzeption ueber die Kontur konventioneller Durchstroemturbinen. (orig.)

  18. Trend zur Transdisziplinarität – Kritische Einordnung einer ambivalenten Praxis qualitativer Stadtforschung

    Directory of Open Access Journals (Sweden)

    Monika Streule

    2013-11-01

    Full Text Available Dieser Beitrag befasst sich mit der Rolle von transdisziplinären Herangehensweisen innerhalb der Stadtforschung mittels einer theoretisch-methodischen Besprechung dieses Forschungsfeldes. Ausgehend von einem kurzen Rückblick auf die Methodengeschichte und die wichtigsten epistemologischen Debatten der empirischen Stadtforschung diskutiere ich die Frage, welche neue Erkenntnis ein transdisziplinärer Zugang in der Betrachtung des Städtischen bringt, genauer: Wie kann Transdisziplinarität produktiv in eine kritische Forschungspraxis umgesetzt und als Strategie für Stadtforschung fruchtbar gemacht werden? Der Beitrag beschreibt die empirische Prägung der westeuropäischen Stadtforschungspraxis durch vorerst überwiegend intuitive transdisziplinäre Zugänge. Dabei zeige ich auf, dass insbesondere die aus der postmodernen und poststrukturalistischen Wende resultierende wissenschaftliche Reflexivität, die neu bewertete Ethnografie und der Fokus auf die soziale Produktion von Raum als zentrale sozialwissenschaftliche und erkenntnistheoretische Stränge die Stadtforschung auf inhaltlicher und struktureller Ebene bis heute durchziehen. In der kritischen Weiterentwicklung ebendieser methodischen und theoretischen Grundlagen der Stadtforschung sehe ich eine wesentliche Voraussetzung für Forschende, um Transdisziplinarität heute in eine explizite empirische Praxis zu übersetzen. Die große Bandbreite aktueller transdisziplinärer Ansätze bündle ich schließlich schematisch und lote ihre Möglichkeiten und Grenzen für die Stadtforschung aus. URN: http://nbn-resolving.de/urn:nbn:de:0114-fqs1401175

  19. Progression of atrial fibrillation in the REgistry on Cardiac rhythm disORDers assessing the control of Atrial Fibrillation cohort

    DEFF Research Database (Denmark)

    De Vos, Cees B; Breithardt, Günter; Camm, A John;

    2012-01-01

    Paroxysmal atrial fibrillation (AF) may progress to persistent AF. We studied the clinical correlates and the effect of rhythm-control strategy on AF progression.......Paroxysmal atrial fibrillation (AF) may progress to persistent AF. We studied the clinical correlates and the effect of rhythm-control strategy on AF progression....

  20. Phase statistics approach to human ventricular fibrillation

    Science.gov (United States)

    Wu, Ming-Chya; Watanabe, Eiichi; Struzik, Zbigniew R.; Hu, Chin-Kun; Yamamoto, Yoshiharu

    2009-11-01

    Ventricular fibrillation (VF) is known to be the most dangerous cardiac arrhythmia, frequently leading to sudden cardiac death (SCD). During VF, cardiac output drops to nil and, unless the fibrillation is promptly halted, death usually ensues within minutes. While delivering life saving electrical shocks is a method of preventing SCD, it has been recognized that some, though not many, VF episodes are self-terminating, and understanding the mechanism of spontaneous defibrillation might provide newer therapeutic options for treatment of this otherwise fatal arrhythmia. Using the phase statistics approach, recently developed to study financial and physiological time series, here, we reveal the timing characteristics of transient features of ventricular tachyarrhythmia (mostly VF) electrocardiogram (ECG) and find that there are three distinct types of probability density function (PDF) of phase distributions: uniform (UF), concave (CC), and convex (CV). Our data show that VF patients with UF or CC types of PDF have approximately the same probability of survival and nonsurvival, while VF patients with CV type PDF have zero probability of survival, implying that their VF episodes are never self-terminating. Our results suggest that detailed phase statistics of human ECG data may be a key to understanding the mechanism of spontaneous defibrillation of fatal VF.

  1. [Progress of anticoagulation therapy in atrial fibrillation].

    Science.gov (United States)

    Hernández Olmedo, Miguel; Suárez Fernández, Carmen

    2015-08-07

    Atrial fibrillation is currently a very prevalent disease and it represents one of the most common causes of disabling stroke. Antithrombotic therapies have reduced the incidence of this complication although they pose many limitations and difficulties. As a result, a large number of high risk patients do not receive an appropriate treatment. In recent years, four new oral anticoagulants (NOAC) with relevant advantages in comparison to vitaminK antagonists have been released. Four large phaseiii clinical trials have demonstrated that NOAC are at least as safe and efficacious as warfarin in stroke prevention in non-valve atrial fibrillation patients with moderate-high thrombotic risk, being their main advantage the reduction in intracranial hemorrhage. The arrival of these drugs has caused great expectations in the management of these patients but also new doubts. Lacking data in some subgroups of frail patients, the absence of specific antidotes available and specially their high cost represent nowadays the main limitations for their generalization. Copyright © 2014 Elsevier España, S.L.U. All rights reserved.

  2. Atrial fibrillation associated with exogenous subclinical hyperthyroidism.

    Science.gov (United States)

    Patanè, Salvatore; Marte, Filippo

    2010-11-19

    Subclinical hyperthyroidism is an increasingly recognized entity that is defined as a normal serum free thyroxine and free triiodothyronine levels with a thyroid-stimulating hormone level suppressed below the normal range and usually undetectable. It has been reported that subclinical hyperthyroidism is not associated with coronary heart disease or mortality from cardiovascular causes but it is sufficient to induce arrhythmias including atrial fibrillation and atrial flutter. It has also been reported that increased factor X activity in patients with subclinical hyperthyroidism represents a potential hypercoagulable state. Moreover acute myocardial infarction has been reported during L-thyroxine substitution therapy. Far more common and relatively less studied is exogenous subclinical hyperthyroidism caused by L-thyroxine administration to thyroidectomized or hypothyroid patients or patients with simple or nodular goiter. We present a case of atrial fibrillation associated with exogenous subclinical hyperthyroidism, in a 72-year-old Italian woman. Also this case focuses attention on the importance of a correct evaluation of subclinical hyperthyroidism.

  3. Fibril morphology and tendon mechanical properties in patellar tendinopathy: effects of heavy slow resistance training

    DEFF Research Database (Denmark)

    Kongsgaard, Mads; Qvortrup, Klaus; Larsen, Jytte;

    2010-01-01

    BACKGROUND: Patellar tendinopathy is characterized by pathologic abnormalities. Heavy slow resistance training (HSR) is effective in the management of patellar tendinopathy, but the underlying functional mechanisms remain elusive. PURPOSE: To investigate fibril morphology and mechanical properties...... area decreased (-26% +/- 21%, P = .04) in tendinopathic tendons after HSR. CONCLUSION: Fibril morphology is abnormal in tendinopathy, but tendon mechanical properties are not. Clinical improvements after HSR were associated with changes in fibril morphology toward normal fibril density and mean fibril...... area. Heavy slow resistance training improved the clinical outcome of patellar tendinopathy, and these improvements were associated with normalization of fibril morphology, most likely due to a production of new fibrils....

  4. Erictho und die Figuren der Entzweiung – Vorüberlegungen zu einer Poetik der Emergenz in Lucans Bellum civile

    Directory of Open Access Journals (Sweden)

    Alexander Arweiler

    2010-10-01

    Full Text Available Im Ausgang von der Möglichkeit, mit dem Wort figura Gestalten der Handlungsebene, dynamisch gefaßte Gedanken- / Wortgebilde und Erscheinungsweisen von Phänomenen geistiger und materieller Natur zu bezeichnen, läßt sich das Bellum civile als Werk beschreiben, an dessen Grund die Figur der Entzweiung steht, die durch eine Poetik der Emergenz in den Stoff entfaltet wird. Die vorgeschlagene Lektüre des Bellum civile wendet sich damit gegen das verbreitete Verständnis des Textes als eines (politischen, moralischen Kommentars zum Bürgerkrieg und kehrt die Hierarchie um: Der (sekundäre Bürgerkriegsstoff soll die zugrunde liegende Figur der Entzweiung explizieren, wird von dieser aber nicht gedeutet, sondern benutzt. Emergenz tritt als poetische Verhältnisbestimmung an die Stelle chronologischer und kausaler Erklärungsmodelle und behauptet eine bleibende Verbindung von Untergrund und hervortretendem Relief (Ereignis, Wesen, Gestalt. Dementsprechend lassen sich die Gestalten der Handlungsebene (figurae als Ekstasen des Textes fassen, die in einer Verdichtung des Textes aus dessen Oberfläche hervortreten, zugleich gemeinsam mit anderen Textelementen Erscheinungsweisen (figurae der abstrakten Figur der Entzweiung sind. Im sechsten Buch des Bellum civile wird die Ekstase insbesondere im Hervorgehen der Erictho aus der Konstruktion eines raum-zeitlich unmöglichen Thessalien kompositionell konkretisiert und imitationstechnischumgesetzt: Die ovidisch geprägte Begegnungsszenezwischen Sextus Pompeius und der textuell übercodierten Erictho bereitet den Boden für die Auffassung der Hexesowohl als einer Fortschreibung der nach Ovid vergehenden Sibylle als auch als figura (Gestalt und Erscheinungsweise Roms, das sich in einer Trennung von sich selbst gegenübertritt und im (poetischen Kannibalismus die Entzweiung zumVollzug bringt.

  5. Practical implementation of a quality management system in a radiological department; Praktische Umsetzung von Qualitaetsmanagement in einer radiologischen Abteilung

    Energy Technology Data Exchange (ETDEWEB)

    Huber, S.; Zech, C.J. [Klinikum der Ludwig-Maximilians-Universitaet, Campus Innenstadt, Institut fuer Klinische Radiologie, Muenchen (Germany)

    2011-10-15

    This article describes the architecture of a project aiming to implement a DIN EN ISO 9001 quality management system in a radiological department. It is intended to be a practical guide to demonstrate each step of the project leading to certification of the system. In a planning phase resources for the implementation of the project have to be identified and a quality management (QM) group as core team has to be formed. In the first project phase all available documents have to be checked and compiled in the QM manual. Moreover all relevant processes of the department have to be described in so-called process descriptions. In a second step responsibilities for the project are identified. Customer and employee surveys have to be carried out and a nonconformity management system has to be implemented. In this phase internal audits are also needed to check the new QM system, which is finally tested in the external certification audit with reference to its conformity with the standards. (orig.) [German] Dieser Beitrag beschreibt die Grundarchitektur einer Projektplanung fuer die Etablierung eines Qualitaetsmanagement(QM)-Systems mit Zertifizierung nach DIN EN ISO 9001 fuer eine radiologische Abteilung basierend auf eigenen Erfahrungen und der einschlaegigen Praxis. Er soll ein praktischer Leitfaden fuer die einzelnen Arbeitsschritte waehrend eines solchen Zertifizierungsprojekts sein. In einer Planungsphase muessen die erforderlichen Ressourcen fuer ein Zertifizierungsprojekt erfasst und eine QM-Gruppe als Kernteam gebildet werden. In der ersten Projektphase werden die Dokumente und Vorlagen der Abteilung gesichtet und in einem Handbuch gelenkt. Zudem muessen fuer alle wesentlichen Prozesse Beschreibungen erstellt werden. In einer zweiten Projektphase werden weitere Verantwortlichkeiten im Rahmen eines Beauftragtenwesens festgelegt, Befragungen relevanter ''Kunden'' (Patienten, Zuweiser) und Mitarbeiter durchgefuehrt und ein Fehler- und

  6. Mechanical Properties of Single Collagen Fibrils Revealed by Force Spectroscopy

    Science.gov (United States)

    Graham, John; Phillips, Charlotte; Grandbois, Michel

    2004-03-01

    In the field of biomechanics, collagen fibrils are believed to be robust mechanical structures characterized by a low extensibility. Until very recently, information on the mechanical properties of collagen fibrils could only be derived from ensemble measurements performed on complete tissues such as bone, skin and tendon. Here we measure force-elongation/relaxation profiles of single collagen fibrils using atomic force microscopy-based force spectroscopy. The elongation profiles indicate that in vitro assembled heterotrimeric type I collagen fibrils are characterized by a large extensibility. Numerous discontinuities and a plateau in the force profile indicate major reorganization occurs within the fibrils in the 1.5 -- 4.5 nN range. Our study demonstrates that newly assembled collagen fibrils are robust structures with a significant reserve of elasticity that could play a determinant role in cellular motion in the context of tissue growth and morphogenesis. In contrast, homotrimeric collagen fibrils corresponding to osteogenesis imperfecta pathology exhibit a marked difference in their elasticity profile.

  7. Peptide concentration alters intermediate species in amyloid β fibrillation kinetics

    Energy Technology Data Exchange (ETDEWEB)

    Garvey, M., E-mail: megan.garvey@molbiotech.rwth-aachen.de [Max-Planck Research Unit for Enzymology of Protein Folding, Weinbergweg 22, 06120 Halle (Saale) (Germany); Morgado, I., E-mail: immorgado@ualg.pt [Max-Planck Research Unit for Enzymology of Protein Folding, Weinbergweg 22, 06120 Halle (Saale) (Germany)

    2013-04-12

    Highlights: ► Aβ(1–40) aggregation in vitro has been monitored at different concentrations. ► Aβ(1–40) fibrillation does not always follow conventional kinetic mechanisms. ► We demonstrate non-linear features in the kinetics of Aβ(1–40) fibril formation. ► At high Aβ(1–40) concentrations secondary processes dictate fibrillation speed. ► Intermediate species may play significant roles on final amyloid fibril development. -- Abstract: The kinetic mechanism of amyloid aggregation remains to be fully understood. Investigations into the species present in the different kinetic phases can assist our comprehension of amyloid diseases and further our understanding of the mechanism behind amyloid β (Aβ) (1–40) peptide aggregation. Thioflavin T (ThT) fluorescence and transmission electron microscopy (TEM) have been used in combination to monitor Aβ(1–40) aggregation in vitro at both normal and higher than standard concentrations. The observed fibrillation behaviour deviates, in several respects, from standard concepts of the nucleation–polymerisation models and shows such features as concentration-dependent non-linear effects in the assembly mechanism. Aβ(1–40) fibrillation kinetics do not always follow conventional kinetic mechanisms and, specifically at high concentrations, intermediate structures become populated and secondary processes may further modify the fibrillation mechanism.

  8. Amyloid fibrils nucleated and organized by DNA origami constructions

    Science.gov (United States)

    Udomprasert, Anuttara; Bongiovanni, Marie N.; Sha, Ruojie; Sherman, William B.; Wang, Tong; Arora, Paramjit S.; Canary, James W.; Gras, Sally L.; Seeman, Nadrian C.

    2014-07-01

    Amyloid fibrils are ordered, insoluble protein aggregates that are associated with neurodegenerative conditions such as Alzheimer's disease. The fibrils have a common rod-like core structure, formed from an elongated stack of β-strands, and have a rigidity similar to that of silk (Young's modulus of 0.2-14 GPa). They also exhibit high thermal and chemical stability and can be assembled in vitro from short synthetic non-disease-related peptides. As a result, they are of significant interest in the development of self-assembled materials for bionanotechnology applications. Synthetic DNA molecules have previously been used to form intricate structures and organize other materials such as metal nanoparticles and could in principle be used to nucleate and organize amyloid fibrils. Here, we show that DNA origami nanotubes can sheathe amyloid fibrils formed within them. The fibrils are built by modifying the synthetic peptide fragment corresponding to residues 105-115 of the amyloidogenic protein transthyretin and a DNA origami construct is used to form 20-helix DNA nanotubes with sufficient space for the fibrils inside. Once formed, the fibril-filled nanotubes can be organized onto predefined two-dimensional platforms via DNA-DNA hybridization interactions.

  9. Fibril formation from pea protein and subsequent gel formation.

    Science.gov (United States)

    Munialo, Claire Darizu; Martin, Anneke H; van der Linden, Erik; de Jongh, Harmen H J

    2014-03-19

    The objective of this study was to characterize fibrillar aggregates made using pea proteins, to assemble formed fibrils into protein-based gels, and to study the rheological behavior of these gels. Micrometer-long fibrillar aggregates were observed after pea protein solutions had been heated for 20 h at pH 2.0. Following heating of pea proteins, it was observed that all of the proteins were hydrolyzed into peptides and that 50% of these peptides were assembled into fibrils. Changes on a structural level in pea proteins were studied using circular dichroism, transmission electron microscopy, and particle size analysis. During the fibril assembly process, an increase in aggregate size was observed, which coincided with an increase in thioflavin T binding, indicating the presence of β-sheet aggregates. Fibrils made using pea proteins were more branched and curly. Gel formation of preformed fibrils was induced by slow acidification from pH 7.0 to a final pH of around pH 5.0. The ability of pea protein-based fibrillar gels to fracture during an amplitude sweep was comparable to those of soy protein and whey protein-based fibrillar gels, although gels prepared from fibrils made using pea protein and soy protein were weaker than those of whey protein. The findings show that fibrils can be prepared from pea protein, which can be incorporated into protein-based fibrillar gels.

  10. Sequence dependent aggregation of peptides and fibril formation

    Science.gov (United States)

    Hung, Nguyen Ba; Le, Duy-Manh; Hoang, Trinh X.

    2017-09-01

    Deciphering the links between amino acid sequence and amyloid fibril formation is key for understanding protein misfolding diseases. Here we use Monte Carlo simulations to study the aggregation of short peptides in a coarse-grained model with hydrophobic-polar (HP) amino acid sequences and correlated side chain orientations for hydrophobic contacts. A significant heterogeneity is observed in the aggregate structures and in the thermodynamics of aggregation for systems of different HP sequences and different numbers of peptides. Fibril-like ordered aggregates are found for several sequences that contain the common HPH pattern, while other sequences may form helix bundles or disordered aggregates. A wide variation of the aggregation transition temperatures among sequences, even among those of the same hydrophobic fraction, indicates that not all sequences undergo aggregation at a presumable physiological temperature. The transition is found to be the most cooperative for sequences forming fibril-like structures. For a fibril-prone sequence, it is shown that fibril formation follows the nucleation and growth mechanism. Interestingly, a binary mixture of peptides of an aggregation-prone and a non-aggregation-prone sequence shows the association and conversion of the latter to the fibrillar structure. Our study highlights the role of a sequence in selecting fibril-like aggregates and also the impact of a structural template on fibril formation by peptides of unrelated sequences.

  11. Optimierung der Hefetechnologie mit dem Ziel einer Verbesserung der Geschmacksstabilität im Praxismaßstab

    OpenAIRE

    Hartwig, Axel

    2008-01-01

    Die Planung und Inbetriebnahme eines neuen Hefeherführsystems in Form einer Assimilationsanlage sowie großtechnische Gärversuche an 3-Sud-ZKGs mit Variation verschiedener Anstellparameter zur Erhöhung des SO2-Gehaltes des Bieres stellen den Kern der Arbeit dar. Im Rahmen von Versuchsreihen an Assimilationen unter Einsatz von drei verschiedenen Belüftungssystemen konnte gezeigt werden, dass eine einfache Belüftungsvorrichtung in Form eines T-Stücks mit Luftzufuhr durch ein perforiertes Rohr...

  12. Proinsulin C-peptide interferes with insulin fibril formation

    Energy Technology Data Exchange (ETDEWEB)

    Landreh, Michael [Department of Medical Biochemistry and Biophysics, Karolinska Institutet, S-171 77 Stockholm (Sweden); Stukenborg, Jan-Bernd [Department of Women' s and Children' s Health, Astrid Lindgren Children' s Hospital, Pediatric Endocrinology Unit, Karolinska Institutet and University Hospital, S-17176 Stockholm (Sweden); Willander, Hanna [KI-Alzheimer' s Disease Research Center, NVS Department, Karolinska Institutet, S-141 86 Stockholm (Sweden); Soeder, Olle [Department of Women' s and Children' s Health, Astrid Lindgren Children' s Hospital, Pediatric Endocrinology Unit, Karolinska Institutet and University Hospital, S-17176 Stockholm (Sweden); Johansson, Jan [KI-Alzheimer' s Disease Research Center, NVS Department, Karolinska Institutet, S-141 86 Stockholm (Sweden); Department of Anatomy, Physiology and Biochemistry, Swedish University of Agricultural Sciences, S-751 23 Uppsala (Sweden); Joernvall, Hans, E-mail: Hans.Jornvall@ki.se [Department of Medical Biochemistry and Biophysics, Karolinska Institutet, S-171 77 Stockholm (Sweden)

    2012-02-17

    Highlights: Black-Right-Pointing-Pointer Insulin and C-peptide can interact under insulin fibril forming conditions. Black-Right-Pointing-Pointer C-peptide is incorporated into insulin aggregates and alters aggregation lag time. Black-Right-Pointing-Pointer C-peptide changes insulin fibril morphology and affects backbone accessibility. Black-Right-Pointing-Pointer C-peptide may be a regulator of fibril formation by {beta}-cell granule proteins. -- Abstract: Insulin aggregation can prevent rapid insulin uptake and cause localized amyloidosis in the treatment of type-1 diabetes. In this study, we investigated the effect of C-peptide, the 31-residue peptide cleaved from proinsulin, on insulin fibrillation at optimal conditions for fibrillation. This is at low pH and high concentration, when the fibrils formed are regular and extended. We report that C-peptide then modulates the insulin aggregation lag time and profoundly changes the fibril appearance, to rounded clumps of short fibrils, which, however, still are Thioflavine T-positive. Electrospray ionization mass spectrometry also indicates that C-peptide interacts with aggregating insulin and is incorporated into the aggregates. Hydrogen/deuterium exchange mass spectrometry further reveals reduced backbone accessibility in insulin aggregates formed in the presence of C-peptide. Combined, these effects are similar to those of C-peptide on islet amyloid polypeptide fibrillation and suggest that C-peptide has a general ability to interact with amyloidogenic proteins from pancreatic {beta}-cell granules. Considering the concentrations, these peptide interactions should be relevant also during physiological secretion, and even so at special sites post-secretory or under insulin treatment conditions in vivo.

  13. Silent Atrial Fibrillation: Definition, Clarification, and Unanswered Issues.

    Science.gov (United States)

    Kennedy, Harold L

    2015-11-01

    Silent or subclinical asymptomatic atrial fibrillation has currently gained wide interest in the epidemiologic, neurologic and cardiovascular communities. The association of brief episodes of paroxysmal atrial fibrillation or surrogate atrial arrhythmias which predict future clinical adverse events have been established. Nevertheless there exists a confounding array of definitions to indicate its presence without discrete indication of which populations should be examined. Moreover the term "atrial fibrillation burden" (AFB) has emerged from such studies with a plethora of descriptions to prognosticate both arrhythmic and clinical adverse events. This presentation suggests clarification of diagnostic definitions associated with silent atrial fibrillation, and a more precise description of AFB. It examines the populations across the current disease and cardiovascular invasive therapeutic spectrum that lead to both silent atrial fibrillation and AFB. It describes the diagnostic methods of arrhythmia detection utilizing the surface ECG, subcutaneous ECG or intra-cardiac devices and their relationship in seeking meaningful arrhythmic markers of silent atrial fibrillation. Whereas a wide range of clinical risk factors of silent atrial fibrillation have been validated in the literature, there is an ongoing search for those arrhythmic risk factors that precisely identify and prognosticate outcome events in diverse populations at risk of atrial fibrillation and its complications. This presentation identifies this chaos, and focuses attention on the issues to be addressed to facilitate descriptive and comparative scientific studies in the future. It is a call to action specifically to the medical arrhythmic community and its specialty societies (i.e., ISHNE, HRS, EHRA) to begin a quest to unravel the arrhythmic quagmire associated with "silent atrial fibrillation."

  14. Detecting and Diagnosing Atrial Fibrillation (D2AF): study protocol for a cluster randomised controlled trial

    OpenAIRE

    Uittenbogaart, Steven B.; Verbiest-van Gurp, Nicole; Erkens, Petra M. G.; Lucassen, Wim A M; Knottnerus, J. André; Winkens, Bjorn; van Weert, Henk C P M; Stoffers, Henri E. J. H.

    2015-01-01

    Background Atrial fibrillation is a common cause of stroke and other morbidity. Adequate treatment with anticoagulants reduces the risk of stroke by 60 %. Early detection and treatment of atrial fibrillation could prevent strokes. Atrial fibrillation is often asymptomatic and/or paroxysmal. Case-finding with pulse palpation is an effective screening method, but new methods for detecting atrial fibrillation have been developed. To detect paroxysmal atrial fibrillation ambulatory rhythm recordi...

  15. YKL-40 levels and atrial fibrillation in the general population

    DEFF Research Database (Denmark)

    Marott, Sarah C W; Benn, Marianne; Johansen, Julia S

    2013-01-01

    BACKGROUND: Atrial fibrillation is associated with inflammation. In contrast to inflammatory markers like C-reactive protein (CRP) and fibrinogen produced in the liver, YKL-40 is produced at the site of inflammation including in the myocardium. We hypothesized that elevated plasma YKL-40 levels...... associate with increased risk of atrial fibrillation. METHOD AND RESULTS: We measured plasma YKL-40 in 8731 participants from the prospective Copenhagen City Heart Study including 896 individuals who developed atrial fibrillation during up to 18years of follow-up. Additionally, we measured YKL-40 in 6621...

  16. 'Real-world' atrial fibrillation management in Europe

    DEFF Research Database (Denmark)

    Proietti, Marco; Laroche, Cécile; Opolski, Grzegorz;

    2016-01-01

    AIMS: Atrial fibrillation (AF) is commonly associated with a high risk of stroke, thromboembolism, and mortality. The 1-year follow-up of the EURObservational Research Programme-Atrial Fibrillation (EORP-AF) Pilot Registry demonstrated a high mortality but good outcomes with European Society...... (61.8%). Atrial fibrillation readmissions were frequent, particularly related to arrhythmias and heart failure. On multivariate analyses, any cardiovascular reason for admission rather than AF was significantly associated with increased mortality during the 2-year follow-up. CONCLUSION: In this 2-year...

  17. Die Liebesphilosophie Dietrich von Hildebrands. Ansätze einer Ontologie der Liebe?

    Directory of Open Access Journals (Sweden)

    Valentina Gaudiano

    2012-09-01

    Full Text Available Dieser Essay will die Fragestellung der Liebe in den Vordergrund der philosophischen Forschung rücken; gleichzeitig unternimmt er den Versuch, die ontologischen Kategorien neu zu begründen, und zwar anhand des Phänomens der Liebe. Hilfestellung hierzu bietet die phänomenologische Auseinandersetzung Dietrich von Hildebrands mit dem Wesen der Liebe. Ausgangsposition ist die Feststellung, dass die Liebe zwar immer das Interesse der Philosophen geweckt hat, Forschung gemacht worden ist. Hildebrand zeigt, wie komplex und vielfältig dieses Phänomen ist und eröffnet durch sein Verständnis der Liebe alsWertantwort neueWege, die die Liebe in einen ontologischen Horizont des menschlichen Lebens rücken. Besonders im Dialog mit anderen Denkern, wie u. a. Jean-Luc Marion, rückt eine neue Sicht der Liebe in den Vordergrund, nämlich als ein Prozess des Gebens und Empfangens, der einer Seinsgabe nahe kommt. Allein im Liebesprozess kann die Fülle menschlicher Existenz erfahren werden, allerdings nur insofern sich die Person – zuerst und vor allem – dem absoluten Seinshorizont – Gott schenkt. Abstract This essay is mainly concerned with the discussion of the phenomenon of love within the context of philosophical research. At the same time it is an attempt to give new reasons for the traditional ontological categories with the help of the phenomenon of love. Dietrich von Hildebrandt’s phenomenological discussion of love may prove useful for this analysis. As a point of departure it must be stated that through the ages the theme of love has always aroused the interest of philosophers, but rarely has love become a main topic of their research. Dietrich von Hildebrandt shows the complexity and variety of this phenomenon. By comprehending love as a kind of ‘value response’ he opens up new ways of placing the phenomenon of love within an ontological frame of reference concerning human life. The dialogue with other philosophers, e. g. Jean

  18. Ernährungstherapie und Essverhalten bei Polyzystischem Ovarialsyndrom (PCOS im Rahmen einer Kinderwunschbehandlung

    Directory of Open Access Journals (Sweden)

    Prückler J

    2013-01-01

    Full Text Available Das Polyzystische Ovarialsyndrom ist die womöglich häufigste endokrine Störung prämenopausaler Frauen. Es ist mit einer Beeinträchtigung des Hormonhaushalts, der Fertilität sowie mit Insulinresistenz und Adipositas verbunden. Zur Planung der Ernährungstherapie bei übergewichtigen Patientinnen sind Kenntnisse über Ernährungsweise, Gewichtsverlauf und Essverhalten relevant. Diese wurden von Dezember 2011 bis Mai 2012 in Form eines Fragebogens für Frauen mit und ohne PCOS (n = 24 an der Kinderwunschambulanz des Landesklinikums St.Pölten eingeholt. Der BMI (Median der untersuchten PCOS-Patientinnen blieb zwar zwischen Auftreten des Kinderwunsches (21,6 kg/m2 ± 1,9 IQR und Ambulanzeintritt (21,6 kg/m2 ± 2,3 IQR konstant, jedoch stieg er während der Behandlung auf 22,1 kg/m2 ± 3,7 IQR an. Je häufiger Frauen mit PCOS aufgrund äußerer Reize/Emotionen essen, desto öfter leiden sie unter Heißhunger (r = 0,608; p = 0,047. Auch ein subjektiv schlechteres Hunger-/ Sättigungsgefühl korreliert mit der Heißhungerhäufigkeit (r = 0,576; p = 0,064 und mit dem BMI (r = 0,376; p = 0,254. Letzteres könnte auf veränderte Hunger-/Sättigungshormonspiegel zurückzuführen sein, was auch eine erhöhte Nahrungsaufnahme und somit Übergewicht bedingen könnte. Die meisten Patientinnen nahmen nicht ausreichend gesunde Lebensmittel zu sich. 54,5 % waren sich nicht bewusst, dass Ernährung das Syndrom beeinflussen könne. Ebenso viele würden gerne bezüglich Ernährung beraten werden. Für die diätologische Praxis kann der Schluss gezogen werden, dass gerade während der ambulanten Kinderwunschbehandlung Ernährungstherapie indiziert ist. Damit sollen Gewichtszunahmen eingedämmt und die Nährstoffversorgung für die erwünschte Schwangerschaft optimiert werden.

  19. CHP systems. Integration into existing heating grids; Blockheizkraftwerke. Einbindung in vorhandene Heizungsnetze

    Energy Technology Data Exchange (ETDEWEB)

    Vogelsang, F.W. [COMUNA-metall Blockheizkraftwerke GmbH, Herford (Germany); Schultz, R. [COMUNA-metall Blockheizkraftwerke GmbH, Herford (Germany)

    1996-03-01

    Integration of a CHP system connected in parallel with a recirculation boiler has a number of advantages, but a technically mature control system is required. (orig.) [Deutsch] Die Einbindung einer BHKW-Anlage in Reihenschaltung parallel zum Ruecklauf des Kessels bietet mehrere Vorteile. Ein aufeinander abgestimmter Betrieb von BHKW- und Kesselanlage setzt eine technisch ausgereifte Zentralsteuerung voraus. (orig.)

  20. Simple Model for Identifying Critical Regions in Atrial Fibrillation

    Science.gov (United States)

    Peters, Nicholas S.

    2015-01-01

    Atrial fibrillation (AF) is the most common abnormal heart rhythm and the single biggest cause of stroke. Ablation, destroying regions of the atria, is applied largely empirically and can be curative but with a disappointing clinical success rate. We design a simple model of activation wave front propagation on an anisotropic structure mimicking the branching network of heart muscle cells. This integration of phenomenological dynamics and pertinent structure shows how AF emerges spontaneously when the transverse cell-to-cell coupling decreases, as occurs with age, beyond a threshold value. We identify critical regions responsible for the initiation and maintenance of AF, the ablation of which terminates AF. The simplicity of the model allows us to calculate analytically the risk of arrhythmia and express the threshold value of transversal cell-to-cell coupling as a function of the model parameters. This threshold value decreases with increasing refractory period by reducing the number of critical regions which can initiate and sustain microreentrant circuits. These biologically testable predictions might inform ablation therapies and arrhythmic risk assessment. PMID:25635565

  1. Epigenetic mechanisms in atrial fibrillation: New insights and future directions.

    Science.gov (United States)

    Tao, Hui; Shi, Kai-Hu; Yang, Jing-Jing; Li, Jun

    2016-05-01

    Atrial fibrillation (AF) is the most common sustained arrhythmia. AF is a complex disease that results from genetic and environmental factors and their interactions. In recent years, numerous studies have shown that epigenetic mechanisms significantly participate in AF pathogenesis. Even though a poor understanding of the molecular and electrophysiologic mechanisms of AF, accumulated evidence has suggested that the relevance of epigenetic changes in the development of AF. The aim of this review is to describe the present knowledge about the epigenetic regulatory features significantly participates in AF, and look ahead on new perspectives of epigenetic mechanisms research. Epigenetic regulatory features such as DNA methylation, histone modification, and microRNA influence gene expression by epigenetic mechanisms and by directly binding to various factor response elements in the target gene promoters. Given the role of epigenetic alterations in regulating genes, there is potential for the integration of factors-induced epigenetic alterations as informative factors in the risk assessment process. In this review, new insight into the epigenetic mechanisms in AF pathogenesis is discussed, with special emphasis on DNA methylation, histone modification, and microRNA. Further studies are needed to reveal the potential targets of epigenetic mechanisms, and it can be developed as a therapeutic target for AF.

  2. Effects of Soybean Oil Modified Cellulose Fibril and Organosilane Modified Cellulose Fibril on Crystallization of Polypropylene

    Directory of Open Access Journals (Sweden)

    Sarit Thanomchat

    2015-01-01

    Full Text Available Soybean oil modified cellulose fibril (Oil-g-CF and organosilane modified cellulose fibril (Silane-g-CF were prepared using maleinized soybean oil and hexadecyltrimethoxysilane, respectively. Thus obtained modified cellulose fibril was added to polypropylene by a simple melt mixing on a hotplate. PP/modified CF composites with 4.0 wt% filler content were prepared. The composites were subject to a polarized optical microscope to investigate particle dispersion, supramolecular morphology, and crystallization behavior. It was found that Silane-g-CF exhibited smaller particle sizes with better particle distribution when compared to Oil-g-CF. In addition, the etched composite samples unveiled an increase in a number of spherulite crystals as well as a decrease in the spherulite size. The nonisothermal crystallization study of composites revealed that both Oil-g-CF and Silane-g-CF were capable of nucleating PP by facilitating faster crystallization process and raising the number of spherulites. The DSC results indicated that Silane-g-CF was able to perform a more effective nucleation than Oil-g-CF, judged by a higher crystallization temperature. Moreover, PP composites containing Oil-g-CF and Silane-g-CF had higher crystallinity by 7% and 10%, for the first and the latter, respectively, when compared to neat PP.

  3. Collagen fibril surface displays a constellation of sites capable of promoting fibril assembly, stability, and hemostasis

    Energy Technology Data Exchange (ETDEWEB)

    Orgel, J.P.; Antipova, O.; Sagi, I.; Bitler, A.; Qiu, D.; Wang, R.; Xu, Y.; San Antonio, J.D. (IIT)

    2011-12-14

    Fibrillar collagens form the structural basis of organs and tissues including the vasculature, bone, and tendon. They are also dynamic, organizational scaffolds that present binding and recognition sites for ligands, cells, and platelets. We interpret recently published X-ray diffraction findings and use atomic force microscopy data to illustrate the significance of new insights into the functional organization of the collagen fibril. These data indicate that collagen's most crucial functional domains localize primarily to the overlap region, comprising a constellation of sites we call the 'master control region.' Moreover, the collagen's most exposed aspect contains its most stable part - the C-terminal region that controls collagen assembly, cross-linking, and blood clotting. Hidden beneath the fibril surface exists a constellation of 'cryptic' sequences poised to promote hemostasis and cell - collagen interactions in tissue injury and regeneration. These findings begin to address several important, and previously unresolved, questions: How functional domains are organized in the fibril, which domains are accessible, and which require proteolysis or structural trauma to become exposed? Here we speculate as to how collagen fibrillar organization impacts molecular processes relating to tissue growth, development, and repair.

  4. Effects of low dosage Co-60 irradiation in the course of aseptic arthritis of the knee joint of rabbits; Effekte einer niedrig dosierten Co-60-Bestrahlung auf den Verlauf einer aseptischen Arthritis am Kniegelenk des Kaninchens

    Energy Technology Data Exchange (ETDEWEB)

    Fischer, U.; Koch, F.; Ludewig, E. [Univ. Leipzig (Germany). Veterinaermedizinische Fakultaet; Kamprad, F.; Melzer, R.; Hildebrandt, G. [Leipzig Univ. (Germany). Klinik fuer Strahlentherapie und Radioonkologie

    1998-12-01

    significance. Conclusion: The experiments provide evidence for an antiphlogistic effect of irradiation with 5 times 1.0 Gy in vivo. They support the clinical observations of the efficacy of anti-inflammatory radiotherapy. (orig.) [Deutsch] Ziel: Zahlreiche klinisch-empirische Erhebungen zeigten die Effektivitaet niedriger Strahlendosen in der Therapie schmerzhafter entzuendlich-degenerativer Gelenkerkrankungen. Experimentelle Untersuchungen liegen jedoch kaum vor. Wir untersuchten die Effekte einer lokalen fraktionierten Co-60-Bestrahlung mit 5mal, 1,0 Gy auf eine artifizielle aseptische Arthritis am Kniegelenk des Kaninchens. Material und Methoden: Es wurden drei Einzelversuche (EV) mit jeweils zehn Kaninchen (fuenf Versuchs- und fuenf Kontrolltiere) durchgefuehrt (Versuchsdauer: EV1: 18 Tage; EV2: Sechs Tage; EV3: 29 Tage). Die Induktion der aseptischen Arthritis erfolgte am Tag 0 durch intraartikulaere Injektion von 0,5 ml einer 3%igen Papainloesung (30 000 USP/mg) in das rechte Kniegelenk. Die taeglich fraktionierte lokale Bestrahlung des arthritischen Gelenks mit 5mal, 1,0 Gy wurde an den Tagen 1 bis 5 waehrend einer Kurznarkose durchgefuehrt. Die Kontrollgruppen wurden in analoger Technik an den Tagen 1 bis 5 scheinbestrahlt. Der Verlauf der Arthritis in den Versuchs- und Kontrollgruppen wurde anhand klinischer, laborchemischer und morphometrischer Parameter charakterisiert. Die klinische Untersuchung erfolgte taeglich, die Punktion der Kniegelenke in EV1 wiederholt, in EV2 und EV3 am letzten Versuchstag. Jeweils am Versuchsende wurden die Kniegelenke zur histologischen Analyse nach erfolgter Euthanasie entnommen. Ergebnisse: Die intraartikulaere Injektion von Papain fuehrte bei allen Tieren zu einer perakuten entzuendlichen Reaktion, welche nach einer Woche in die chronische Phase ueberging und sich ueber mehrere Wochen kontinuierlich zurueckbildete. Die lokal bestrahlten Versuchstiere zeigten klinisch eine signifikant schnellere Rueckbildung der entzuendlichen

  5. Genome-wide DNA methylation analysis in permanent atrial fibrillation.

    Science.gov (United States)

    Zhao, Guochang; Zhou, Jian; Gao, Jie; Liu, Yan; Gu, Song; Zhang, Xitao; Su, Pixiong

    2017-10-01

    Atrial fibrillation (AF) is a highly heterogeneous genetic disease; however, the pathogenesis of AF cannot be explained by genetic variants alone. DNA methylation is a heritable method of gene expression regulation, and may be a potential regulatory mechanism in AF. Therefore, in the present study, the genome‑wide DNA methylation pattern in cells derived from the left atrium of patients with permanent AF (n=7) was compared with that of healthy heart donors (n=4) with a normal sinus rhythm (SR). Enriched biological functions of the differentially methylated genes were assessed. Integrated analysis of genome‑wide methylation and mRNA expression profiles was performed, and reverse transcription quantitative‑polymerase chain reaction (RT‑qPCR) was used to determine the expression levels of four selected genes. A total of 417 differentially methylated CpG sites were identified in the fibrillating atrium (P0.17); the majority of which were located in gene‑body and intergenic regions outside of CpG islands. Aberrantly methylated genes participated in the activation of inflammation, sodium and potassium ion transport, fibrosis and the reduction of lipid metabolism. Hypermethylation in the AF susceptible loci, paired‑like homeodomain transcription factor 2 (chromosome 4q25) and coiled‑coil domain containing 141 (chromosome 2q31), as well as hypomethylation in the calcium voltage‑gated channel subunit α1C (chromosome 12p13) locus, were identified in all patients with AF. Of the 420 upregulated and 567 downregulated genes previously identified in patients with AF relative to those with normal SR (fold‑change >2.0; P≤0.05), 12 genes were hypomethylated and eight genes were hypermethylated in each group, respectively (|β|>0.2: Peffect of DNA methylation on gene expression. These results suggest that DNA methylation‑mediated regulation of gene expression may serve an important role in AF pathogenesis, and several susceptible AF CpG loci were

  6. A roadmap to improve the quality of atrial fibrillation management : proceedings from the fifth Atrial Fibrillation Network/European Heart Rhythm Association consensus conference

    NARCIS (Netherlands)

    Kirchhof, Paulus; Breithardt, Guenter; Bax, Jeroen; Benninger, Gerlinde; Blomstrom-Lundqvist, Carina; Boriani, Giuseppe; Brandes, Axel; Brown, Helen; Brueckmann, Martina; Calkins, Hugh; Calvert, Melanie; Christoffels, Vincent; Crijns, Harry; Dobrev, Dobromir; Ellinor, Patrick; Fabritz, Larissa; Fetsch, Thomas; Freedman, S. Ben; Gerth, Andrea; Goette, Andreas; Guasch, Eduard; Hack, Guido; Haegeli, Laurent; Hatem, Stephane; Haeusler, Karl Georg; Heidbuechel, Hein; Heinrich-Nols, Jutta; Hidden-Lucet, Francoise; Hindricks, Gerd; Juul-Moeller, Steen; Kaeaeb, Stefan; Kappenberger, Lukas; Kespohl, Stefanie; Kotecha, Dipak; Lane, Deirdre A.; Leute, Angelika; Lewalter, Thorsten; Meyer, Ralf; Mont, Lluis; Muenzel, Felix; Nabauer, Michael; Nielsen, Jens C.; Oeff, Michael; Oldgren, Jonas; Oto, Ali; Piccini, Jonathan P.; Pilmeyer, Art; Potpara, Tatjana; Ravens, Ursula; Reinecke, Holger; Rostock, Thomas; Rustige, Joerg; Savelieva, Irene; Schnabel, Renate; Schotten, Ulrich; Schwichtenberg, Lars; Sinner, Moritz F.; Steinbeck, Gerhard; Stoll, Monika; Tavazzi, Luigi; Themistoclakis, Sakis; Tse, Hung Fat; Van Gelder, Isabelle C.; Vardas, Panagiotis E.; Varpula, Timo; Vincent, Alphons; Werring, David; Willems, Stephan; Ziegler, Andre; Lip, Gregory Y. H.; Camm, A. John

    2016-01-01

    At least 30 million people worldwide carry a diagnosis of atrial fibrillation (AF), and many more suffer from undiagnosed, subclinical, or 'silent' AF. Atrial fibrillation-related cardiovascular mortality and morbidity, including cardiovascular deaths, heart failure, stroke, and hospitalizations,

  7. Prognosis of ventricular fibrillation in hospital

    DEFF Research Database (Denmark)

    Jensen, G V; Torp-Pedersen, C; Køber, L

    1992-01-01

    (P = 0.01). Logistic regression analysis demonstrated that heart failure and cardiogenic shock were significant risk factors for in-hospital death among patients with IHD. Among discharged patients 1 and 5 years survival was 78% and 51% for patients with MI, 63% and 25% for patients with IHD, 67......In a retrospective study of 520 patients with in-hospital ventricular fibrillation 421 (81%) had acute myocardial infarction (MI), 66 (13%) had ischaemic heart disease (IHD) without MI, 33 (6%) had no signs of IHD. The in-hospital mortality of these three groups was 51%, 52%, and 27%, respectively...... with known IHD suffering in-hospital VF without AMI have a very poor short- and long-term prognosis. These patients need extensive cardiac examination....

  8. [Atrial fibrillation concomitant with valvular heart disease].

    Science.gov (United States)

    Ishii, Yosuke

    2013-01-01

    Patients with valvular heart disease frequently have atrial fibrillation(AF) due to elevated pressure and dilatation of the left and right atria and pulmonary veins. Guidelines for valvular heart disease and AF recommend that surgical treatment for the valvular heart disease should be performed concomitantly with AF surgery. The Full-Maze procedure has evolved into the gold standard of treatment for medically refractory AF. In addition to the pulmonary vein isolation, the right and left atrial incisions of the Full-Maze procedure are designed to block potential macroreentrant pathways. According to the mechanisms of AF with valvular heart disease, the Full-Maze procedure is more effective for the patients than the pulmonary vein isolation alone.

  9. Propofol effects on atrial fibrillation wavefront delays.

    Science.gov (United States)

    Cervigón, Raquel; Moreno, Javier; Millet, José; Pérez-Villacastín, Julián; Castells, Francisco

    2010-08-01

    Since the cardiac activity during atrial fibrillation (AF) may be influenced by autonomic modulations, in this study, a novel method to quantify the effects of the most common anesthetic agent (propofol) in AF ablation procedures is introduced. This study has two main objectives: first, to assess whether the sedation earlier to radio frequency ablation affects the arrhythmia itself, and second, to provide new information that contributes to a better understanding of the influence of the autonomic nervous system on AF. The methodology presented is based on the measurement of synchronization and delay indexes between two atrial activations at adjacent intracavitary electrodes. These parameters aim to estimate whether two activations at different sites may be caused by the same propagating wavefront, or otherwise, are the consequence of independent wavefronts. The results showed that the mentioned indexes have a different behavior at both atria: the right atrium becomes more synchronized with propofol administration, whereas the synchronization index decreases at the left atrium.

  10. Atrial Fibrillation, Cognitive Decline And Dementia

    Science.gov (United States)

    Alonso, Alvaro; Arenas de Larriva, Antonio P.

    2016-01-01

    Atrial fibrillation (AF) is a common cardiac arrhythmia. Growing evidence supports a role for AF as a risk factor for cognitive decline and dementia. In this review, we summarize epidemiologic observations linking AF with cognitive outcomes, describe potential mechanisms, and explore the impact of AF treatments on cognitive decline and dementia. Community-based, observational studies show a consistent higher rate of cognitive decline and risk of dementia in persons with AF. These associations are partly due to the increased risk of clinical stroke in AF, but other mechanisms, including incidence of silent cerebral infarcts, microbleeds, and cerebral hypoperfusion, are likely additional contributors. Adequate oral anticoagulation and improved management of the overall cardiovascular risk profile in persons with AF offer the promise of reducing the impact of AF on cognitive decline and dementia. PMID:27547248

  11. Pathogenic Mechanisms of Atrial Fibrillation in Obesity

    Directory of Open Access Journals (Sweden)

    O. M. Drapkina

    2016-01-01

    Full Text Available Atrial fibrillation (AF is one of the most common arrhythmias. It reduces quality of life and its duration due to thromboembolic complications. Obesity contributes to the structural and electrical remodeling of atrial myocardium. This leads to occurrence of ectopic foci in the mouths of the pulmonary veins and the disruption of normal electrical conduction in the atria. Systemic inflammation, myocardial fibrosis, cardiomyocyte overload by Na+ and Ca2+ ions, accumulation in the cells of unoxidized metabolic products, imbalance of the autonomic regulation are considered as the main mechanisms of arrhythmogenic substrate formation. Hypertension, insulin resistance, and obstructive sleep apnea, associated with obesity, increase the risk of development and progression of the arrhythmia. Study of pathogenetic mechanisms of AF in obesity is necessary to develop new strategies for its prevention and the creation of more effective methods of treatment of these patients.

  12. Mapping techniques for atrial fibrillation ablation.

    Science.gov (United States)

    Sra, Jasbir; Akhtar, Masood

    2007-12-01

    Atrial fibrillation (AF) is a common arrhythmia. Although significant work still needs to be done, recent advances in understanding the mechanism of AF have led to the development of elegant catheter mapping techniques for ablation of AF. These improved mapping techniques are complemented by an evolution in various imaging and navigational technologies, several of which can now be combined in a process called registration, so that the physician no longer needs to rely solely on a mental image of the anatomy of the left atrium and the pulmonary vein while attempting to ablate the region. Ongoing advances in mapping technique will increase safety and efficacy and it is likely that AF ablation will become the first-line therapy in most patients with this complicated arrhythmia.

  13. Clinical characteristics, management, and control of permanent vs. nonpermanent atrial fibrillation: insights from the RealiseAF survey.

    LENUS (Irish Health Repository)

    Murin, Jan

    2014-01-01

    Atrial fibrillation can be categorized into nonpermanent and permanent atrial fibrillation. There is less information on permanent than on nonpermanent atrial fibrillation patients. This analysis aimed to describe the characteristics and current management, including the proportion of patients with successful atrial fibrillation control, of these atrial fibrillation subsets in a large, geographically diverse contemporary sample.

  14. Praktikum Medizinische Recherche: Erfahrungen mit einer curricular integrierten Schulungsveranstaltung / Medical Information Retrieval Training: a practical training integrated into the curriculum

    Directory of Open Access Journals (Sweden)

    Wagner, Christiane

    2006-12-01

    Full Text Available n June 2004 a course problem oriented learning (POL has been introduced at the medical faculty of the University Leipzig. The course on the topic „Infectology and Immunology“ takes place once a year and lasts for four weeks. It consists of a series of lectures and tutorials, in which small groups of students work on clinical case examples. Also part of the course are some practical training sessions. One of them is a 90 minutes practical training on searching for medical literature, which is organized by the medical library. In 2006 the practical training took place for the third time. The article tells about the development within the three years and the experiences that have been made.

  15. Left Atrial Ablation for Atrial Fibrillation

    Science.gov (United States)

    Sternik, Leonid; Schaff, Hartzel V.; Luria, David; Glikson, Michael; Kogan, Alexander; Malachy, Ateret; First, Maya; Raanani, Ehud

    2011-01-01

    The maze procedure is the gold standard for the ablation of atrial fibrillation, and the “box lesion” around the pulmonary veins is the most important part of this procedure. We have created this lesion with a bipolar radiofrequency ablator, abandoning the usual use of this device (to achieve bilateral epicardial isolation of the pulmonary veins). From March 2004 through the end of May 2010, we performed surgical ablation of atrial fibrillation in 240 patients. Of this number, 205 underwent operation by a hybrid maze technique and the remaining 35 (our study cohort) underwent the creation of a box lesion around the pulmonary veins by means of a bipolar radiofrequency device. Ablation lines were created by connecting the left atriotomy to the amputated left atrial appendage, with 2 ablation lines made with a bipolar radiofrequency device above and below the pulmonary veins. Lesions were made along the transverse and oblique sinuses by epicardial and endocardial application of a bipolar device. The left atrial isthmus was ablated by bipolar radiofrequency and cryoprobe. No complications were associated with the box lesion: 90% and 89% of patients were in sinus rhythm at 3 and 6 months of follow-up, respectively. By creating a box lesion around the pulmonary veins, we expect to improve transmurality by means of epicardial and endocardial ablation of 1 rather than 2 layers of atrial wall, as in epicardial pulmonary vein isolation. Isolation of the entire posterior wall of the left atrium is better electrophysiologically and renders dissection around the pulmonary veins unnecessary. PMID:21494518

  16. Minimally invasive surgery for atrial fibrillation.

    Science.gov (United States)

    Zembala, Michael O; Suwalski, Piotr

    2013-11-01

    Atrial fibrillation (AF) remains the most common cardiac arrhythmia, affecting nearly 2% of the general population worldwide. Minimally invasive surgical ablation remains one of the most dynamically evolving fields of modern cardiac surgery. While there are more than a dozen issues driving this development, two seem to play the most important role: first, there is lack of evidence supporting percutaneous catheter based approach to treat patients with persistent and long-standing persistent AF. Paucity of this data offers surgical community unparalleled opportunity to challenge guidelines and change indications for surgical intervention. Large, multicenter prospective clinical studies are therefore of utmost importance, as well as honest, clear data reporting. Second, a collaborative methodology started a long-awaited debate on a Heart Team approach to AF, similar to the debate on coronary artery disease and transcatheter valves. Appropriate patient selection and tailored treatment options will most certainly result in better outcomes and patient satisfaction, coupled with appropriate use of always-limited institutional resources. The aim of this review, unlike other reviews of minimally invasive surgical ablation, is to present medical professionals with two distinctly different, approaches. The first one is purely surgical, Standalone surgical isolation of the pulmonary veins using bipolar energy source with concomitant amputation of the left atrial appendage-a method of choice in one of the most important clinical trials on AF-The Atrial Fibrillation Catheter Ablation Versus Surgical Ablation Treatment (FAST) Trial. The second one represents the most complex approach to this problem: a multidisciplinary, combined effort of a cardiac surgeon and electrophysiologist. The Convergent Procedure, which includes both endocardial and epicardial unipolar ablation bonds together minimally invasive endoscopic surgery with electroanatomical mapping, to deliver best of the

  17. Radiofrequency ablation for treatment of atrial fibrillation.

    Science.gov (United States)

    Safaei, Nasser; Montazerghaem, Hossein; Azarfarin, Rasoul; Alizadehasl, Azin; Alikhah, Hossein

    2011-01-01

    Atrial Fibrillation (AF) is the most common cardiac arrhythmia which represents a major public health problem. The main purpose of this research is to evaluate the Radiofrequency (RF) ablation effects in the patients with chronic AF scheduled for cardiac surgery because of different heart diseases. The descriptive and prospective study was conducted on 60 patients with AF scheduled for surgery along with RF ablation. The data were collected by questionnaire and included: patients' age, sex, NYHA class, operation type, past medical history, type and cause of valvular heart disease, preoperative ECG (electrocardiogram), duration of surgery, clamping time, cardiopulmonary bypass, and RF ablation time. RF ablation was followed by the main operation. The follow up examination, ECG, and echocardiography were performed 3 and 6 months after operation. The mean age of patients was 48±10 years (18-71 years). Forty one patients had permanent AF and 19 had the persistent AF. The left ventricular ejection fraction was 48.27±9.75 percent before operation, and reached to 56.27±7.87 percent after the surgery (P<0.001). The mean NYHA class before the surgery was 2.83±0.68 which decreased to 1.34±0.46 6 months after the surgery with RF ablation (P<0.001). One patient (1.6%) died after surgery. Complete relief and freedom from AF recurrence was observed in 70% of patients in the mean follow up in 7 months after the surgery. The sinus rhythm with efficient atrial contraction was established in 100% of discharged patients. RF ablation is an effective procedure to cure atrial fibrillation in patients undergoing cardiac surgeries.

  18. Internationaler und globaler Diskurs über ethische Grundlagen universaler Rechtsgeltung: Selbstbestimmung als Grundlage oder Verhinderung einer globalen Ethik?

    Directory of Open Access Journals (Sweden)

    Angelika Emmerich-Fritsche

    2012-02-01

    Full Text Available Allgemeinmenschliche Unrechtserfahrungen und globale Gefahren offenbaren die Notwendigkeit und Möglichkeit einer (holistischen universalen ethischen Rechtsbegründung. Ungeachtet der dekonstruktiven Kritik bleiben Diskurs und Konsens bewährte, allgemein anerkannte prozedurale Regeln zur Entdeckung sowie zur Begründung der Verbindlichkeit von Normen. Zur Erkennung eines universalen (und nicht nur internationalen Rechtsgrundes kann sich der Diskurs jedoch nicht auf Staaten und Internationale Organisationen beschränken, sondern muss auch Völker und Individuen (colère publique sowie andere global aktive Rechtssubjekte in das Entdeckungsverfahren einbeziehen. Völkerrechtlich verbindlich anerkannt ist nur eine dünne Schicht universeller Grundnormen (ius cogens. Darüber hinaus haben sich die Menschenrechte als Weltethik etabliert, die staatlicher Willkür entgegentritt und jedenfalls entsprechend dem Leitbild der Allgemeinen Erklärung der Menschenrechte auch mit dem vernunftrechtlichen Ideal eines selbstbestimmten und zugleich sozial eingebundenen Menschen verbunden ist. Dieser ethische internationale Standard beansprucht (neben nicht zu leugnenden realistisch-machtpolitischen Einflüssen die Rechtsetzung in den politischen Foren und institutionalisierten Prozessen der Staaten und internationalen Organisationen zu leiten. Unmittelbar gehen universelle Normen aus welt(zivilgesellschaftlichen (transnationalen Diskursen hervor, insbesondere in den Formen privatautonomer Weltrechtsbildung. Darin sowie im weltweiten Kampf der um Selbstbestimmung ringenden Völker und Menschen gegen Willkürherrschaft manifestiert sich die Emanzipation der Selbstbestimmung von einer abendländischen Errungenschaft zum universellen Recht auf Recht(mitgestaltung als ethische Basis globaler, internationaler und staatlicher Rechtsgeltung.

  19. Zur so genannten gegengeschlechtlichen Besetzungspraxis. Nebst einer Besprechung der aktuellen Publikationen von Knaus sowie Beghelli und Talmelli

    Directory of Open Access Journals (Sweden)

    Saskia Maria Woyke

    2012-05-01

    Full Text Available Das Thema der Singstimmen beschäftigt die Musikwissenschaft spätestens seit dem so genannten "performative turn" der Geisteswissenschaften vor nunmehr fast zwei Jahrzehnten intensiver denn je. Positiverweise aber verlagert sich das Interesse auf die Stimmen, die Vokalprofile selbst, in Verbindung mit den Rollenprofilen, ebenso wie auf die Frage der Geschlechterbilder, die in ihnen übertragen werden, statt in vornehmlich biographisch orientierten Angaben über die Sängerinnen und Sänger zu verharren.Diese eher späte Entwicklung hat mit der Schwierigkeit der allgemeinen wie wissenschaftlichen Beschreibung einer aufgezeichneten oder gar verklungenen Stimme zu tun. Gleichzeitig sind die Geschlechterdiskurse im Umfeld der Stimmaufführungen verschiedener Epochen, Jahrzehnte und Orte, jedenfalls bis ca. 1750 trotz bemerkenswerter Ansätze seitens der Geschlechterforschung noch nicht gänzlich aufgearbeitet, was zur Folge hat, dass die Stimmforschung, die die Kategorie des Geschlechts einbeziehen will, hier oft nicht nur mit einer, sondern zwei nahezu Unbekannten operieren muss. Eine Aufzählung der entsprechenden neuesten Literatur zum Thema wird im Folgenden unterlassen, würde sie doch den Raum überschreiten oder aber als exemplarische Auswahl Wertvolles auslassen.

  20. Dronedarone in high-risk permanent atrial fibrillation

    DEFF Research Database (Denmark)

    Connolly, Stuart J; Camm, A John; Halperin, Jonathan L

    2011-01-01

    Dronedarone restores sinus rhythm and reduces hospitalization or death in intermittent atrial fibrillation. It also lowers heart rate and blood pressure and has antiadrenergic and potential ventricular antiarrhythmic effects. We hypothesized that dronedarone would reduce major vascular events in ...

  1. Analysis of amyloid fibrils in the cheetah (Acinonyx jubatus).

    Science.gov (United States)

    Bergström, Joakim; Ueda, Mitsuharu; Une, Yumi; Sun, Xuguo; Misumi, Shogo; Shoji, Shozo; Ando, Yukio

    2006-06-01

    Recently, a high prevalence of amyloid A (AA) amyloidosis has been documented among captive cheetahs worldwide. Biochemical analysis of amyloid fibrils extracted from the liver of a Japanese captive cheetah unequivocally showed that protein AA was the main fibril constituent. Further characterization of the AA fibril components by sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) and Western blot analysis revealed three main protein AA bands with approximate molecular weights of 8, 10 and 12 kDa. Mass spectrometry analysis of the 12-kDa component observed in SDS-PAGE and Western blotting confirmed the molecular weight of a 12,381-Da peak. Our finding of a 12-kDa protein AA component provides evidence that the cheetah SAA sequence is longer than the previously reported 90 amino acid residues (approximately 10 kDa), and hence SAA is part of the amyloid fibril.

  2. Dabigatran use in Danish atrial fibrillation patients in 2011

    DEFF Research Database (Denmark)

    Sørensen, Rikke; Gislason, Gunnar; Torp-Pedersen, Christian;

    2013-01-01

    Objective: Dabigatran was recently approved for anticoagulation in patients with atrial fibrillation (AF); data regarding real-world use, comparative effectiveness and safety are sparse. Design: Pharmacoepidemiological cohort study. Methods/settings: From nationwide registers, we identified...

  3. Pharmacological Management of Atrial Fibrillation: One, None, One Hundred Thousand

    Directory of Open Access Journals (Sweden)

    Fabiana Lucà

    2011-01-01

    This paper summarizes the available evidence regarding the efficacy of medications used for acute management of AF, rhythm and ventricular rate control, and stroke prevention in patients with atrial fibrillation and focuses on the current pharmacological agents.

  4. [New oral anticoagulants for atrial fibrillation: a neurologist's view

    NARCIS (Netherlands)

    Dijk, E.J. van; Koudstaal, P.J.; Roos, Y.B.; Brouwers, P.J.; Kappelle, L.J.

    2012-01-01

    - Recent randomized controlled trials have shown that new oral anticoagulants (dabigatran, rivaroxaban en apixaban) in patients with atrial fibrillation are equally or more effective in preventing cerebral infarction than vitamin K antagonists (VKA).- New oral anticoagulants cause significant less i

  5. Imaging of Ventricular Fibrillation and Defibrillation: The Virtual Electrode Hypothesis.

    Science.gov (United States)

    Boukens, Bastiaan J; Gutbrod, Sarah R; Efimov, Igor R

    2015-01-01

    Ventricular fibrillation is the major underlying cause of sudden cardiac death. Understanding the complex activation patterns that give rise to ventricular fibrillation requires high resolution mapping of localized activation. The use of multi-electrode mapping unraveled re-entrant activation patterns that underlie ventricular fibrillation. However, optical mapping contributed critically to understanding the mechanism of defibrillation, where multi-electrode recordings could not measure activation patterns during and immediately after a shock. In addition, optical mapping visualizes the virtual electrodes that are generated during stimulation and defibrillation pulses, which contributed to the formulation of the virtual electrode hypothesis. The generation of virtual electrode induced phase singularities during defibrillation is arrhythmogenic and may lead to the induction of fibrillation subsequent to defibrillation. Defibrillating with low energy may circumvent this problem. Therefore, the current challenge is to use the knowledge provided by optical mapping to develop a low energy approach of defibrillation, which may lead to more successful defibrillation.

  6. Atrioverter : An implantable device for the treatment of atrial fibrillation

    NARCIS (Netherlands)

    Wellens, HJJ; Lau, CP; Luderitz, B; Akhtar, M; Waldo, AL; Camm, AJ; Timmermans, C; Tse, HF; Jung, W; Jordaens, L; Ayers, G

    1998-01-01

    Background-During atrial fibrillation, electrophysiological changes occur in atrial tissue that favor the maintenance of the arrhythmia and facilitate recurrence after conversion to sinus rhythm. An implantable defibrillator connected to right atrial and coronary sinus defibrillation leads allows pr

  7. He I Vector Magnetometry of Field Aligned Superpenumbral Fibrils

    CERN Document Server

    Schad, T A; Lin, Haosheng

    2013-01-01

    Atomic-level polarization and Zeeman effect diagnostics in the neutral helium triplet at 10830 angstroms in principle allow full vector magnetometry of fine-scaled chromospheric fibrils. We present high-resolution spectropolarimetric observations of superpenumbral fibrils in the He I triplet with sufficient polarimetric sensitivity to infer their full magnetic field geometry. He I observations from the Facility Infrared Spectropolarimeter (FIRS) are paired with high-resolution observations of the Halpha 6563 angstroms and Ca II 8542 angstroms spectral lines from the Interferometric Bidimensional Spectrometer (IBIS) from the Dunn Solar Telescope in New Mexico. Linear and circular polarization signatures in the He I triplet are measured and described, as well as analyzed with the advanced inversion capability of the "Hanle and Zeeman Light" (HAZEL) modeling code. Our analysis provides direct evidence for the often assumed field alignment of fibril structures. The projected angle of the fibrils and the inferred ...

  8. Effect of hydroxypropyl methylcellulose on collagen fibril formation in vitro.

    Science.gov (United States)

    Ding, Cuicui; Zhang, Min; Tian, Huilin; Li, Guoying

    2013-01-01

    Collagen and hydroxypropyl methylcellulose (HPMC) were mixed to obtain blends and the effect of HPMC on collagen self-assembly was studied. As deduced from atomic force microscopy (AFM), the amount of nuclei in collagen-HPMC solutions was changed with the addition of HPMC. Under physiological conditions, the kinetics curves of fibril formation showed that the turbidity of blends at 313 nm was higher than that of native collagen. More HPMC was involved in the hydrogel network for blends with higher HPMC/collagen. However, both the thermal stability and the storage moduli of hydrogels, which was evaluated by UV and rheological measurements respectively, reached the maximum just when HPMC/collagen=0.25. Furthermore, it was showed by AFM that denser fibrils with smaller diameter would be obtained as HPMC/collagen0.25) would bring about fibrils with larger diameter. However, HPMC did not significantly affect the characteristic D-periods of the fibrils for all blends.

  9. Women Sex Importance in Stroke Patients with Atrial Fibrillation

    Directory of Open Access Journals (Sweden)

    Cemile Handan Mısırlı

    2014-08-01

    Full Text Available OBJECTIVE: It was shown the differences in age, risk factors and treatment between women and men in stroke patients with atrial fibrillation METHODS: The stroke patients with atrial fibrillation who were hospitalized in our department at the last 2 years were seperated into 2 groups of aged above 75 and below 75, investigated with CHADS2 and CHA2DS2VASc scores and looked at the sex differences of women and men. RESULTS: Stroke ratio according to sex was statistically meaningful especially in women above the age of 75. Risc factors also were founded in elderly women and CHA2DS2VASc scores were higher in women than men so more anticoagulan treatment were begun. No differences were shown between sexes at lone atrial fibrillation and no treatment were begun. CONCLUSION: Women with atrial fibrillation had more risk factors, higher stroke rate and higher anticoagulation treatment.

  10. Collagenous fibril texture of the human knee joint menisci.

    Science.gov (United States)

    Petersen, W; Tillmann, B

    1998-04-01

    Anatomical and clinical literature describes the arrangement of collagen fibrils in the human meniscus as being "arcade-like". The "arcade-like" orientation, mainly running in a radial direction in the internal circumference and in a circular direction in the external circumference, was found in polarization light microscopic studies. This, however, does not provide a mechanical explanation for the direction of meniscus tears. In view of this contradiction collagen fibrils in the menisci of adults aged from 18 to 85 years were exposed layer-by-layer to study their arrangement by scanning electron microscopy. The results obtained by this procedure were compared to the path of the split lines. Scanning electron microscopy reveals three distinct layers in the meniscus cross section: (1) The tibial and femoral sides of the meniscus surfaces are covered by a meshwork of thin fibrils with a diameter of approximately 30 nm. (2) Beneath the superficial network there is a layer of lamellalike collagen fibril bundles on the tibial and femoral surface. In the area of the external circumference of the anterior and posterior segments the bundles of collagen fibrils are arranged in a radial direction. In all other parts the collagen fibril bundles intersect at various angles. (3) The main portion of the meniscus collagen fibrils are located in the central region between the femoral and the tibial surface layers. Everywhere in the central main portion of the meniscus the bundles of collagen fibrils are orientated in a circular manner. The split lines in the region of the internal circumference of the menisci are arranged in a circular manner, generally running in a radial direction in the portions adjacent to the base. Scanning electron microscopy reveals that the direction of the split lines depends on the orientation of the collagen fibrils in the superficial lamellar layer. The arcade-like path of the collagen fibrils described in the literature can not be confirmed either by

  11. Echocardiographic quantification of systolic function during atrial fibrillation

    DEFF Research Database (Denmark)

    Olsen, Flemming Javier; Jørgensen, Peter Godsk; Dons, Maria;

    2016-01-01

    It is often difficult to provide an exact echocardiographic measure of left ventricular systolic function in patients with atrial fibrillation, partly because of the varying cycle length affecting pre and afterload and partly because of the increased heart rate often accompanying this arrhythmia....... We sought to elucidate two points: whether it would be possible to correct for the cyclic variance in systolic output, and if global longitudinal strain is preferable to the left ventricular ejection fraction at evaluating systolic function during atrial fibrillation....

  12. Methods for structural characterization of prefibrillar intermediates and amyloid fibrils

    DEFF Research Database (Denmark)

    Langkilde, Annette Eva; Vestergaard, Bente

    2009-01-01

    Protein fibrillation is first and foremost a structural phenomenon. Adequate structural investigation of the central conformational individuals of the fibrillation process is however exceedingly difficult. This is due to the nature of the process, which may be described as a dynamically evolving...... equilibrium between a large number of structural species. These are furthermore of highly diverging sizes and present in very uneven amounts and timeframes. Different structural methods have different strengths and limitations. These, and in particular recent advances within solution analysis...

  13. Antiarrhythmic Effect Of Antioxidants In Patients With Atrial Fibrillation

    OpenAIRE

    Khabchabov PhD, Rustam; RG PhD, Khabchabov; ER PhD, Makhmudova

    2016-01-01

    Resume In accordance with modern concepts, one of the leading roles in the development of paroxysmal atrial fibrillation and flutter, belongs - the restructuring of the myocardium, in second place - sick sinus syndrome and in third place - the presence of accessory pathways and hormonal disorders. The development of atrial fibrillation and flutter in the structural pathology, primarily begins with of drugs if it does not work, we have to carry out ablation. Providing proper, effective and imp...

  14. Stroke and bleeding in atrial fibrillation with chronic kidney disease

    DEFF Research Database (Denmark)

    Olesen, Jonas Bjerring; Lip, Gregory Y.H.; Kamper, Anne-Lise

    2012-01-01

    Both atrial fibrillation and chronic kidney disease increase the risk of stroke and systemic thromboembolism. However, these risks, and the effects of antithrombotic treatment, have not been thoroughly investigated in patients with both conditions.......Both atrial fibrillation and chronic kidney disease increase the risk of stroke and systemic thromboembolism. However, these risks, and the effects of antithrombotic treatment, have not been thoroughly investigated in patients with both conditions....

  15. Nanomechanical mapping of hydrated rat tail tendon collagen I fibrils.

    Science.gov (United States)

    Baldwin, Samuel J; Quigley, Andrew S; Clegg, Charlotte; Kreplak, Laurent

    2014-10-21

    Collagen fibrils play an important role in the human body, providing tensile strength to connective tissues. These fibrils are characterized by a banding pattern with a D-period of 67 nm. The proposed origin of the D-period is the internal staggering of tropocollagen molecules within the fibril, leading to gap and overlap regions and a corresponding periodic density fluctuation. Using an atomic force microscope high-resolution modulus maps of collagen fibril segments, up to 80 μm in length, were acquired at indentation speeds around 10(5) nm/s. The maps revealed a periodic modulation corresponding to the D-period as well as previously undocumented micrometer scale fluctuations. Further analysis revealed a 4/5, gap/overlap, ratio in the measured modulus providing further support for the quarter-staggered model of collagen fibril axial structure. The modulus values obtained at indentation speeds around 10(5) nm/s are significantly larger than those previously reported. Probing the effect of indentation speed over four decades reveals two distinct logarithmic regimes of the measured modulus and point to the existence of a characteristic molecular relaxation time around 0.1 ms. Furthermore, collagen fibrils exposed to temperatures between 50 and 62°C and cooled back to room temperature show a sharp decrease in modulus and a sharp increase in fibril diameter. This is also associated with a disappearance of the D-period and the appearance of twisted subfibrils with a pitch in the micrometer range. Based on all these data and a similar behavior observed for cross-linked polymer networks below the glass transition temperature, we propose that collagen I fibrils may be in a glassy state while hydrated.

  16. Supersaturation-limited amyloid fibrillation of insulin revealed by ultrasonication.

    Science.gov (United States)

    Muta, Hiroya; Lee, Young-Ho; Kardos, József; Lin, Yuxi; Yagi, Hisashi; Goto, Yuji

    2014-06-27

    Amyloid fibrils form in supersaturated solutions via a nucleation and growth mechanism. We proposed that ultrasonication may be an effective agitation to trigger nucleation that would otherwise not occur under the persistent metastability of supersaturation. However, the roles of supersaturation and effects of ultrasonication have not been elucidated in detail except for limited cases. Insulin is an amyloidogenic protein that is useful for investigating the mechanisms underlying amyloid fibrillation with biological relevance. We studied the alcohol-induced amyloid fibrillation of insulin using various concentrations of 2,2,2-trifluoroethanol and 1,1,1,3,3,3-hexafluoro-2-propanol at pH 2.0 and 4.8. Ultrasonic irradiation effectively triggered fibrillation under conditions in which insulin retained persistent supersaturation. Structural analyses by circular dichroism, Fourier transform infrared spectroscopy, transmission electron microscopy, and atomic force microscopy revealed that the dominant structures of fibrils varied between parallel and antiparallel β-sheets depending on the solvent conditions. pH and alcohol concentration-dependent phase diagrams showed a marked difference before and after the ultrasonic treatment, which indicated that the persistent metastability of supersaturation determined the conformations of insulin. These results indicate the importance of an alternative view of amyloid fibrils as supersaturation-limited crystal-like aggregates formed above the solubility limit. © 2014 by The American Society for Biochemistry and Molecular Biology, Inc.

  17. Supersaturation-limited Amyloid Fibrillation of Insulin Revealed by Ultrasonication*

    Science.gov (United States)

    Muta, Hiroya; Lee, Young-Ho; Kardos, József; Lin, Yuxi; Yagi, Hisashi; Goto, Yuji

    2014-01-01

    Amyloid fibrils form in supersaturated solutions via a nucleation and growth mechanism. We proposed that ultrasonication may be an effective agitation to trigger nucleation that would otherwise not occur under the persistent metastability of supersaturation. However, the roles of supersaturation and effects of ultrasonication have not been elucidated in detail except for limited cases. Insulin is an amyloidogenic protein that is useful for investigating the mechanisms underlying amyloid fibrillation with biological relevance. We studied the alcohol-induced amyloid fibrillation of insulin using various concentrations of 2,2,2-trifluoroethanol and 1,1,1,3,3,3-hexafluoro-2-propanol at pH 2.0 and 4.8. Ultrasonic irradiation effectively triggered fibrillation under conditions in which insulin retained persistent supersaturation. Structural analyses by circular dichroism, Fourier transform infrared spectroscopy, transmission electron microscopy, and atomic force microscopy revealed that the dominant structures of fibrils varied between parallel and antiparallel β-sheets depending on the solvent conditions. pH and alcohol concentration-dependent phase diagrams showed a marked difference before and after the ultrasonic treatment, which indicated that the persistent metastability of supersaturation determined the conformations of insulin. These results indicate the importance of an alternative view of amyloid fibrils as supersaturation-limited crystal-like aggregates formed above the solubility limit. PMID:24847058

  18. Inhibition of insulin fibrillation by osmolytes: Mechanistic Insights

    Science.gov (United States)

    Choudhary, Sinjan; Kishore, Nand; Hosur, Ramakrishna V.

    2015-11-01

    We have studied here using a number of biophysical tools the effects of osmolytes, betaine, citrulline, proline and sorbitol which differ significantly in terms of their physical characteristics such as, charge distribution, polarity, H-bonding abilities etc, on the fibrillation of insulin. Among these, betaine, citrulline, and proline are very effective in decreasing the extent of fibrillation. Proline also causes a substantial delay in the onset of fibrillation in the concentration range (50-250 mM) whereas such an effect is seen for citrulline only at 250 mM, and in case of betaine this effect is not seen at all in the whole concentration range. The enthalpies of interaction at various stages of fibrillation process have suggested that the preferential exclusion of the osmolyte and its polar interaction with the protein are important in inhibition. The results indicate that the osmolytes are most effective when added prior to the elongation stage of fibrillation. These observations have significant biological implications, since insulin fibrillation is known to cause injection amyloidosis and our data may help in designing lead drug molecules and development of potential therapeutic strategies.

  19. Dual chamber pacemaker in the treatment of paroxysmal atrial fibrillation

    Directory of Open Access Journals (Sweden)

    Rađen Goran

    2005-01-01

    Full Text Available Background. Atrial fibrillation is the most frequent cardiac dysrhythmia. The aim of this study was to show the role and the efficacy of a dual chamber pacemaker with the algorithm of atrial dynamic overdrive, in the suppression of paroxysmal atrial fibrillation. Case report. A woman with a classical bradycardia-tachycardia syndrome, and frequent attacks of atrial fibrillation, underwent the implantation of a single chamber permanent pacemaker (VVI. Pacemaker successfully treated the episodes of symptomatic bradycardia, but the patient had frequent attacks of atrial fibrillation, despite the use of different antiarrhythmic drugs, which she did not tolerate well. The decision was made to reimplant a permanent dual chamber pacemaker with the algorithm of atrial dynamic overdrive. The pacemaker was programmed to the basic rate of 75/min, while rate at rest was 55/min. In addition, sotalol was administered. After three months, the patient became asymptomatic with only 4 short − term episodes of atrial fibrillation, and a high level of atrial pacing (99%. Conclusion. In selected patients with bradycardia−tachycardia syndrome, atrial-based pacing seemed to be very effective in reducing the incidence of paroxysmal atrial fibrillation.

  20. Stabilization and anomalous hydration of collagen fibril under heating.

    Directory of Open Access Journals (Sweden)

    Sasun G Gevorkian

    Full Text Available BACKGROUND: Type I collagen is the most common protein among higher vertebrates. It forms the basis of fibrous connective tissues (tendon, chord, skin, bones and ensures mechanical stability and strength of these tissues. It is known, however, that separate triple-helical collagen macromolecules are unstable at physiological temperatures. We want to understand the mechanism of collagen stability at the intermolecular level. To this end, we study the collagen fibril, an intermediate level in the collagen hierarchy between triple-helical macromolecule and tendon. METHODOLOGY/PRINCIPAL FINDING: When heating a native fibril sample, its Young's modulus decreases in temperature range 20-58°C due to partial denaturation of triple-helices, but it is approximately constant at 58-75°C, because of stabilization by inter-molecular interactions. The stabilization temperature range 58-75°C has two further important features: here the fibril absorbs water under heating and the internal friction displays a peak. We relate these experimental findings to restructuring of collagen triple-helices in fibril. A theoretical description of the experimental results is provided via a generalization of the standard Zimm-Bragg model for the helix-coil transition. It takes into account intermolecular interactions of collagen triple-helices in fibril and describes water adsorption via the Langmuir mechanism. CONCLUSION/SIGNIFICANCE: We uncovered an inter-molecular mechanism that stabilizes the fibril made of unstable collagen macromolecules. This mechanism can be relevant for explaining stability of collagen.

  1. Fibrillization kinetics of insulin solution in an interfacial shearing flow

    Science.gov (United States)

    Balaraj, Vignesh; McBride, Samantha; Hirsa, Amir; Lopez, Juan

    2015-11-01

    Although the association of fibril plaques with neurodegenerative diseases like Alzheimer's and Parkinson's is well established, in-depth understanding of the roles played by various physical factors in seeding and growth of fibrils is far from well known. Of the numerous factors affecting this complex phenomenon, the effect of fluid flow and shear at interfaces is paramount as it is ubiquitous and the most varying factor in vivo. Many amyloidogenic proteins have been found to denature upon contact at hydrophobic interfaces due to the self-assembling nature of protein in its monomeric state. Here, fibrillization kinetics of insulin solution is studied in an interfacial shearing flow. The transient surface rheological response of the insulin solution to the flow and its effect on the bulk fibrillization process has been quantified. Minute differences in hydrophobic characteristics between two variants of insulin- Human recombinant and Bovine insulin are found to result in very different responses. Results presented will be in the form of fibrillization assays, images of fibril plaques formed, and changes in surface rheological properties of the insulin solution. The interfacial velocity field, measured from images (via Brewster Angle Microscopy), is compared with computations. Supported by NNX13AQ22G, National Aeronautics and Space Administration.

  2. Effects of climate change on winter wheat; Auswirkung einer Klimaaenderung auf das Wachstum von Winterweizen

    Energy Technology Data Exchange (ETDEWEB)

    Maier, H.M.

    1999-07-01

    und staerkeren Auftreten von Wassermangel zu rechnen. Die Ertragsverluste betrugen bei Trockenstress in der Schossphase 23% bis 32%, bei Trockenstress um die Bluete 8% bis 30%. Die Feldversuchsergebnisse dienten zudem der Ueberpruefung und Verbesserung des Ausgangsmodells CERES-Wheat/NSIM und der Entwicklung des neuen Modells WOOP. Die Klasseneinteilung des in der objektorientierten Sprache Smalltalk geschriebenen Programms wurde dazu neu organisiert. Prinzipielle Veraenderungen betrafen ferner die Teilmodelle Entwicklung (neue Entwicklungsskala, neue Phyllochron- und Stadienberechnung), Wachstum und Verdunstung. Das Modell WOOP gab die Kornertraege gut wieder (Standardfehler der Schaetzung fuer alle Varianten 8,4 dt/ha, fuer die ungestoerten Varianten 3,5 dt/ha). Das optimierte und validierte Modell wurde zur Berechnung der Kornertraege unter kuenftigen Klimabedingungen fuer die drei bayerischen Standorte Kempten, Koesching und Wuerzburg eingesetzt. Dazu dienten die Daten des Deutschen Klimarechenzentrums (Modell ECHAM-1) fuer vier IPCC-Szenarien. Die berechneten Ertragsrueckgaenge lagen zwischen 10% und 80%. Sie hingen vorwiegend von der Bodentiefe ab. Die Ertragsverluste durch eine Klimaaenderung sind an trockenen oder flachgruendigen Standorten Bayerns hoeher als an feuchten und tiefgruendigen. Die Konsequenzen einer Klimaaenderung fuer Bayern werden diskutiert. (orig.)

  3. Interaktiver Kleingruppenunterricht für Medizinstudenten der Klinischen Semester in einer onkologischen Gemeinschaftspraxis [Interactive medical education for medical students in an oncology group practice

    Directory of Open Access Journals (Sweden)

    Weide, Rudolf

    2007-02-01

    Full Text Available [english] Background: The education of medical students to become qualified medical doctors should be improved in Germany. Reasons for this are medical teachers not properly trained in education, a lack of quality control and low esteem of medical education, too large groups, no intensive relationship between students and academic teachers and the triad for medical teachers at university hospitals to qualify in their discipline, to perform science and lecture medical students. At the same time experienced associate professors who left university are not integrated optimally in medical education programs. Pilotproject: Since 1998 we are performing weekend seminars for advanced medical students. 3 students are educated by 1 teacher. The topics of the training are differential diagnosis of anaemia, polyglobulinaemia, leukocytopenia, leukocytosis, thrombocytopenia, thrombocytosis, training in morphology, diagnosis and treatment of leukaemia and lymphoma and principles of communication skills. Patient cases are presented in a problem oriented learning manner using patient files, a video microscope and a computer based learning programme for interactive purposes.Results: So far 320 students have participated in our seminars. Systematic quality evaluation of the teaching reveals excellent marks for practical relevance, learning atmosphere, didactics and effectiveness. Impressions of the routine work in an oncology group practice widens the experience of the students.Conclusion: Academical training for medical students is feasable and successful in an oncology group practice. This teaching model enables external associate professors to give their education in the environment where they are working and may relieve the University personally and financially.[german] Hintergrund: Die Ausbildung von Medizinstudenten zu guten Ärzten ist in Deutschland verbesserungsbedürftig. Die Gründe für ein suboptimales Studium sind die häufig fehlende Vernetzung von

  4. Planung einer Mobile Learning Application für medizinische Lerninhalte [Planning of a mobile learning application for medical contents

    Directory of Open Access Journals (Sweden)

    Walther, Patrick

    2013-11-01

    Full Text Available [english] Due to the high popularity of mobile devices barriers for mobile learning are becoming less. Place-and time-independent access to information is part of everyday life. The number of mobile applications is steadily growing. Currently there are more than 500,000 mobile applications, so-called apps, available for the Apple iPhone/iPad which can be downloaded in the Apple iTunes Store. More than ten percent of these apps are mobile learning applications.Before starting development of a mobile app we need to analyze all requirements accurately. This is due to the fact that there is a multiplicity of different operating systems with different functionalities. This paper shows general properties of so-called native, hybrid, and web applications and advantages and disadvantages in development and use of the finished application. In addition, current software, which supports the development of a mobile application is explained.Finally the differences of the various development options are shown based on concrete mobile applications.[german] Aufgrund der hohen Verbreitung mobiler Endgeräte werden die Barrieren für das mobile Lernen immer geringer und orts- und zeitunabhängiger Zugriff auf Informationen ist längst im Alltag angekommen. Die Zahl mobiler Applikation wächst stetig an. So stehen beispielsweise aktuell mehr als 500.000 mobile Applikationen, sogenannte Apps, für das Apple iPhone/iPad, dem Nutzer über den Apple iTunes Store bereit. Hiervon sind mehr als zehn Prozent mobile Lernapplikationen.Vor der eigentlichen Entwicklung einer App muss, u.a. aufgrund der Vielzahl mobiler Betriebssysteme und Funktionen der verschiedenen mobilen Endgeräte, zuvor eine genaue Bedarfsanalyse durchgeführt werden um die passende Entwicklungsvariante zu wählen.In diesem Beitrag werden die verschiedenen Möglichkeiten (nativ, hybrid, web zur Entwicklung einer mobilen Applikation, als auch deren Vor- und Nachteile bei der Entwicklung und Nutzung der

  5. A system for automatic biocide treatment of coolant cycles with concentration; Ein System einer automatisierten Biozidbehandlung von Kuehlkreislaeufen mit Eindickung

    Energy Technology Data Exchange (ETDEWEB)

    Lutat, A.; Pflug, H.D.; Schoenfelder, T. [KNG, Rostock (Germany)

    2000-07-01

    wuerde die Wartezeit verlaengern und einen Betriebsstillstand oder zumindest eine Lastabsenkung erfordern. Zur Entlastung des Betriebspersonals empfiehlt es sich, eine aufwendige und haeufig durchzufuehrende Mikroziddosierung zu automatisieren. Im folgenden wird das Verfahren einer automatisierten Stosschlorung vorgestellt, wie sie im Kraftwerk Rostock seit mehreren Jahren erfolgreich angewandt wird. Im einzelnen werden beschrieben: - Kuehlturmzusatzwasseraufbereitung mit messtechnischer Ausruestung. - Untersuchungen zum mikrobiellen Wachstum in Kuehlwasser in einer Pilotanlage. - Konzept der Biozidbehandlung des Kraftwerks Rostock. - Kuehlturmbetrieb und Chlorkonzentrationen waehrend einer Stosschlorung. (orig.)

  6. How can we best detect atrial fibrillation?

    Science.gov (United States)

    Harris, K; Edwards, D; Mant, J

    2012-01-01

    Atrial fibrillation (AF) is an arrhythmia of increasing prevalence associated with a reducible risk of stroke. We conducted a systematic review to address five questions relating to how we can best detect AF: 1. Are there useful screening tests to determine who should have a 12-lead electrocardiogram (ECG)? Potential screening tests, all with acceptable sensitivity, include pulse palpation, single-lead ECG and newer technologies such as modified sphygmomanometers or a finger probe device. Pulse palpation has a high number of false positives, but is the cheapest method. 2. Is it more effective to offer 12-lead ECGs to the whole population (or specific sub-groups) or only to those who screen positive for AF? The cost-effectiveness of new devices, such as a modified blood pressure monitor, needs to be assessed. It is more cost-effective to opportunistically screen people rather than to offer a 12-lead ECG to everybody. 3. How accurate are different healthcare professionals and interpretative software at diagnosing AF on ECG? Definitive diagnosis of AF should be by 12-lead ECG, interpreted by someone with appropriate expertise. Computer software is not currently sensitive enough to be used alone to diagnose AF on ECG. Primary care practitioners may not accurately detect AF on ECG, but consistently high accuracy can be achieved by healthcare professionals with adequate training. 4. How best can we diagnose paroxysmal atrial fibrillation (PAF)? In patients in whom PAF is suspected, longer periods of monitoring will detect more cases of PAF. 5. What is the impact of the use of different ECG monitoring strategies (e.g. Holter monitoring, serial ECGs, continuous ECG) on AF detection rates post-stroke? In patients post-stroke, a single ECG will miss cases of PAF which can be detected by longer duration monitoring such as Holter monitoring, cardiac event recorders and serial ECGs. Further research into the cost-effectiveness of these methods, the duration of monitoring

  7. The Relation of Atrial Fibrillation and Inflammation Do Inflammation Imply the Pathogenesis of Atrial Fibrillation?

    Institute of Scientific and Technical Information of China (English)

    Ruibin Fu; Pingsheng Wu; Shulin Wu

    2008-01-01

    @@ Atrial fibrillation (AF),the most commonly encountered arrhythmia in clinical practice,is associated with a 2-fold increase in total cardiovascular mortality[1],as well as the potential for substantial morbidity,including stroke,congestive heart failure,and cardiomyopathy.Its incidence and prevalence are increasing,and it represents a growing clinical and economic burden.Owing to relative inefficacy and side effects of current pharmacological and non-pharmacological therapy for AF,it remains a great challenge to improve primary and secondary AF prevention strategies to reduce this potentially enormous health burden.

  8. Family history of atrial fibrillation is associated with earlier-onset and more symptomatic atrial fibrillation

    DEFF Research Database (Denmark)

    Gundlund, Anna; Fosbøl, Emil Loldrup; Kim, Sunghee

    2016-01-01

    BACKGROUND: We addressed whether patients with a family history of atrial fibrillation (AF) were diagnosed as having AF earlier in life, were more symptomatic, and had worse outcomes compared with those without a family history of AF. METHODS: Using the ORBIT-AF, we compared symptoms and disease ......, and had more severe AF-related symptoms. No differences were found between the 2 groups in the risk of AF progression (adjusted hazard ratio [HR] 0.98, 95% CI 0.85-1.14), stroke, non-central nervous system embolism, or transient ischemic attack (adjusted HR 0.95, 95% CI 0.67-1.34), all...

  9. [Anja Wilhelmi, Menschenbilder aus Reval und St. Peterburg. Reiseeindrücke einer Engländerin um 1840] / Paul Kaegbein

    Index Scriptorium Estoniae

    Kaegbein, Paul

    2006-01-01

    Arvustus: Anja Wilhelmi, Menschenbilder aus Reval und St. Peterburg. Reiseeindrücke einer Engländerin um 1840. In: Kollektivität und Individualität. Hamburg: Kovaè, 2001. S. 224-242. Elizabeth Rigby 1840. aastal Londonis anonüümselt ilmunud raamatust "Letters from the shores of the Baltic"

  10. [Antjekathrin Grassmann. Zu den wirtschaftlichen und persönlichen Beziehungen Lübecks ins Baltikum im Lichte einer unbeachteten mittelalterlichen Quellegruppe]/ Dennis Hortmuth

    Index Scriptorium Estoniae

    Hormuth, Dennis

    2012-01-01

    Arvustus: Antjekathrin Grassmann. Zu den wirtschaftlichen und persönlichen Beziehungen Lübecks ins Baltikum im Lichte einer unbeachteten mittelalterlichen Quellegruppe. In: Leder ist Brot. Beiträge zur norddeutschen Landes- und Archivgeseten. Schwerin 2011. S. 125-135

  11. [Anja Wilhelmi, Menschenbilder aus Reval und St. Peterburg. Reiseeindrücke einer Engländerin um 1840] / Paul Kaegbein

    Index Scriptorium Estoniae

    Kaegbein, Paul

    2006-01-01

    Arvustus: Anja Wilhelmi, Menschenbilder aus Reval und St. Peterburg. Reiseeindrücke einer Engländerin um 1840. In: Kollektivität und Individualität. Hamburg: Kovaè, 2001. S. 224-242. Elizabeth Rigby 1840. aastal Londonis anonüümselt ilmunud raamatust "Letters from the shores of the Baltic"

  12. [Antjekathrin Grassmann. Zu den wirtschaftlichen und persönlichen Beziehungen Lübecks ins Baltikum im Lichte einer unbeachteten mittelalterlichen Quellegruppe]/ Dennis Hortmuth

    Index Scriptorium Estoniae

    Hormuth, Dennis

    2012-01-01

    Arvustus: Antjekathrin Grassmann. Zu den wirtschaftlichen und persönlichen Beziehungen Lübecks ins Baltikum im Lichte einer unbeachteten mittelalterlichen Quellegruppe. In: Leder ist Brot. Beiträge zur norddeutschen Landes- und Archivgeseten. Schwerin 2011. S. 125-135

  13. Self-organization and the dynamical nature of ventricular fibrillation

    Science.gov (United States)

    Jalife, José; Gray, Richard A.; Morley, Gregory E.; Davidenko, Jorge M.

    1998-03-01

    This article reviews recent data supporting the conjecture that, in the structurally and electrophysiologically normal heart, cardiac fibrillation is not a totally random phenomenon. Experimental and numerical studies based on the theory of excitable media suggest that fibrillation in the mammalian ventricles is the result of self-organized three-dimensional (3-D) electrical rotors giving rise to scroll waves that move continuously (i.e., drift) throughout the heart at varying speeds. A brief review of studies on the dynamics of rotors in two-dimensional (2-D) and 3-D excitable media is presented with emphasis on the experimental demonstration of such dynamics in cardiac muscle of various species. The discussion is centered on rotor dynamics in the presence and the absence of structural heterogeneities, and in the phenomena of drifting and anchoring, which in the electrocardiogram (ECG) may manifest as life-threatening cardiac rhythm disturbances. For instance, in the rabbit heart, a single electrical rotor that drifts rapidly throughout the ventricles gives rise to complex patterns of excitation. In the ECG such patterns are indistinguishable from ventricular fibrillation. On the other hand, a rotor that anchors to a discontinuity or defect in the muscle (e.g., a scar, a large artery or a bundle of connective tissue) may result in stationary rotating activity, which in the ECG is manifested as a form of so-called "monomorphic" ventricular tachycardia. More recent data show that ventricular fibrillation occurs in mammals irrespective of size or species. While in small hearts, such as those of mice and rabbits, a single drifting or meandering rotor can result in fibrillation, in larger hearts, such as the sheep and possibly the human, fibrillation occurs in the form of a relatively small number of coexisting but short-lived rotors. Overall, the work discussed here has paved the way for a better understanding of the mechanisms of fibrillation in the normal, as well

  14. Fracture and Growth Are Competing Forces Determining the Fate of Conformers in Tau Fibril Populations*

    Science.gov (United States)

    Meyer, Virginia; Holden, Michael R.; Weismiller, Hilary A.; Eaton, Gareth R.; Eaton, Sandra S.; Margittai, Martin

    2016-01-01

    Tau fibrils are pathological aggregates that can transfer between neurons and then recruit soluble Tau monomers by template-assisted conversion. The propagation of different fibril polymorphs is thought to be a contributing factor to phenotypic diversity in Alzheimer disease and other Tauopathies. We found that a homogeneous population of Tau fibrils composed of the truncated version K18 (residues 244–372) gradually converted to a new set of fibril conformers when subjected to multiple cycles of seeding and growth. Using double electron-electron resonance (DEER) spectroscopy, we observed that the distances between spin labels at positions 311 and 328 in the fibril core progressively decreased. The findings were corroborated by changes in turbidity, morphology, and protease sensitivity. Fibrils that were initially formed under stirring conditions exhibited an increased fragility compared with fibrils formed quiescently after multiple cycles of seeding. The quiescently formed fibrils were marked by accelerated growth. The difference in fragility and growth between the different conformers explains how the change in incubation condition could lead to the amplification of a minor subpopulation of fibrils. Under quiescent conditions where fibril breakage is minimal, faster growing fibrils have a selective advantage. The findings are of general importance as they suggest that changes in selective pressures during fibril propagation in the human brain could result in the emergence of new fibril conformers with varied clinicopathological consequences. PMID:27080260

  15. Fracture and Growth Are Competing Forces Determining the Fate of Conformers in Tau Fibril Populations.

    Science.gov (United States)

    Meyer, Virginia; Holden, Michael R; Weismiller, Hilary A; Eaton, Gareth R; Eaton, Sandra S; Margittai, Martin

    2016-06-03

    Tau fibrils are pathological aggregates that can transfer between neurons and then recruit soluble Tau monomers by template-assisted conversion. The propagation of different fibril polymorphs is thought to be a contributing factor to phenotypic diversity in Alzheimer disease and other Tauopathies. We found that a homogeneous population of Tau fibrils composed of the truncated version K18 (residues 244-372) gradually converted to a new set of fibril conformers when subjected to multiple cycles of seeding and growth. Using double electron-electron resonance (DEER) spectroscopy, we observed that the distances between spin labels at positions 311 and 328 in the fibril core progressively decreased. The findings were corroborated by changes in turbidity, morphology, and protease sensitivity. Fibrils that were initially formed under stirring conditions exhibited an increased fragility compared with fibrils formed quiescently after multiple cycles of seeding. The quiescently formed fibrils were marked by accelerated growth. The difference in fragility and growth between the different conformers explains how the change in incubation condition could lead to the amplification of a minor subpopulation of fibrils. Under quiescent conditions where fibril breakage is minimal, faster growing fibrils have a selective advantage. The findings are of general importance as they suggest that changes in selective pressures during fibril propagation in the human brain could result in the emergence of new fibril conformers with varied clinicopathological consequences. © 2016 by The American Society for Biochemistry and Molecular Biology, Inc.

  16. Wool fibril sponges with perspective biomedical applications

    Energy Technology Data Exchange (ETDEWEB)

    Patrucco, A., E-mail: a.patrucco@bi.ismac.cnr.it [CNR-ISMAC, Italian National Research Council, Institute for Macromolecular Studies, Corso G. Pella 16, 13900, Biella (Italy); Cristofaro, F., E-mail: francesco.cristofaro01@universitadipavia.it [Department of Molecular Medicine, INSTM UdR of Pavia, University of Pavia, Viale Taramelli 3/B, 27100, Pavia (Italy); Centre for Health Technologies (CHT), University of Pavia, Via Ferrata 1, 27100, Pavia (Italy); Simionati, M., E-mail: m.simionati@bi.ismac.cnr.it [CNR-ISMAC, Italian National Research Council, Institute for Macromolecular Studies, Corso G. Pella 16, 13900, Biella (Italy); Zoccola, M., E-mail: m.zoccola@bi.ismac.cnr.it [CNR-ISMAC, Italian National Research Council, Institute for Macromolecular Studies, Corso G. Pella 16, 13900, Biella (Italy); Bruni, G., E-mail: giovanna.bruni@unipv.it [Department of Chemistry, — Physical-Chemistry Section, University of Pavia, Viale Taramelli 16, 27100, Pavia (Italy); Fassina, L., E-mail: lorenzo.fassina@unipv.it [Centre for Health Technologies (CHT), University of Pavia, Via Ferrata 1, 27100, Pavia (Italy); Department of Electrical, Computer and Biomedical Engineering, University of Pavia, Via Ferrata 1, 27100, Pavia (Italy); Visai, L., E-mail: livia.visai@unipv.it [Department of Molecular Medicine, INSTM UdR of Pavia, University of Pavia, Viale Taramelli 3/B, 27100, Pavia (Italy); Centre for Health Technologies (CHT), University of Pavia, Via Ferrata 1, 27100, Pavia (Italy); Department of Occupational Medicine, Toxicology and Environmental Risks, S. Maugeri Foundation, IRCCS, Via S. Boezio, 28, 27100, Pavia (Italy); Magenes, G., E-mail: giovanni.magenes@unipv.it [Centre for Health Technologies (CHT), University of Pavia, Via Ferrata 1, 27100, Pavia (Italy); Department of Electrical, Computer and Biomedical Engineering, University of Pavia, Via Ferrata 1, 27100, Pavia (Italy); and others

    2016-04-01

    Sheep's wool was used as a natural source to prepare keratin microfibril sponges for scaffolding, by disruption of the histological structure of the fibres through mild alkali treatment, followed by ultrasonication, casting and salt-leaching. The wool sponges showed highly interconnected porosity (93%) and contain intrinsic sites of cellular recognition that mimic the extracellular matrix (ECM). They displayed good thermal and water stability due to the conversion of disulphide cystine bonds into shorter monosulphide lanthionine intermolecular bonds, but significantly swelled in water, because of the high hydrophilicity and porosity, with a volume increasing up to 38%. Nevertheless, sponges were stable in water without structural changes, with a neutral pH in aqueous media, and showed excellent resilience to repeated compression stresses. According to in vitro biocompatibility assays, wool fibril sponges showed a good cell adhesion and proliferation as proved by MTT, FDA assays and SEM observations. The unique structure of the cortical cell network made by wool keratin proteins with controlled-size macro-porosity suitable for cell guesting, and nutrient feeding, provides an excellent scaffold for future tissue engineering applications. - Highlights: • Scaffolds were prepared from wool exploiting the fibres' histology structure. • The scaffold showed high interconnected micro- and macro-porosity. • The microscopic structure is very similar to the extracellular bone matrix. • Scaffolds reversibly swell in water with high resilience to repeated compression. • Composites were cytocompatible and supported the growth of SAOS-2 cell line.

  17. Imaging in percutaneous ablation for atrial fibrillation

    Energy Technology Data Exchange (ETDEWEB)

    Maksimovic, Ruzica [Erasmus Medical Center, Department of Radiology, GD Rotterdam (Netherlands); Institute for Cardiovascular Diseases of the University Medical Center, Belgrade (Czechoslovakia); Dill, Thorsten [Kerckhoff-Heart Center, Department of Cardiology, Bad Nauheim (Germany); Ristic, Arsen D.; Seferovic, Petar M. [Institute for Cardiovascular Diseases of the University Medical Center, Belgrade (Czechoslovakia)

    2006-11-15

    Percutaneous ablation for electrical disconnection of the arrhythmogenic foci using various forms of energy has become a well-established technique for treating atrial fibrillation (AF). Success rate in preventing recurrence of AF episodes is high although associated with a significant incidence of pulmonary vein (PV) stenosis and other rare complications. Clinical workup of AF patients includes imaging before and after ablative treatment using different noninvasive and invasive techniques such as conventional angiography, transoesophageal and intracardiac echocardiography, computed tomography (CT) and magnetic resonance imaging (MRI), which offer different information with variable diagnostic accuracy. Evaluation before percutaneous ablation involves assessment of PVs (PV pattern, branching pattern, orientation and ostial size) to facilitate position and size of catheters and reduce procedure time as well as examining the left atrium (presence of thrombi, dimensions and volumes). Imaging after the percutaneous ablation is important for assessment of overall success of the procedure and revealing potential complications. Therefore, imaging methods enable depiction of PVs and the anatomy of surrounding structures essential for preprocedural management and early detection of PV stenosis and other ablation-related procedures, as well as long-term follow-up of these patients. (orig.)

  18. Atrial Fibrillation Predictors: Importance of the Electrocardiogram.

    Science.gov (United States)

    German, David M; Kabir, Muammar M; Dewland, Thomas A; Henrikson, Charles A; Tereshchenko, Larisa G

    2016-01-01

    Atrial fibrillation (AF) is the most common arrhythmia in adults and is associated with significant morbidity and mortality. Substantial interest has developed in the primary prevention of AF, and thus the identification of individuals at risk for developing AF. The electrocardiogram (ECG) provides a wealth of information, which is of value in predicting incident AF. The PR interval and P wave indices (including P wave duration, P wave terminal force, P wave axis, and other measures of P wave morphology) are discussed with regard to their ability to predict and characterize AF risk in the general population. The predictive value of the QT interval, ECG criteria for left ventricular hypertrophy, and findings of atrial and ventricular ectopy are also discussed. Efforts are underway to develop models that predict AF incidence in the general population; however, at present, little information from the ECG is included in these models. The ECG provides a great deal of information on AF risk and has the potential to contribute substantially to AF risk estimation, but more research is needed.

  19. Atrial fibrillation: effects beyond the atrium?

    Science.gov (United States)

    Wijesurendra, Rohan S; Casadei, Barbara

    2015-03-01

    Atrial fibrillation (AF) is the most common sustained clinical arrhythmia and is associated with significant morbidity, mostly secondary to heart failure and stroke, and an estimated two-fold increase in premature death. Efforts to increase our understanding of AF and its complications have focused on unravelling the mechanisms of electrical and structural remodelling of the atrial myocardium. Yet, it is increasingly recognized that AF is more than an atrial disease, being associated with systemic inflammation, endothelial dysfunction, and adverse effects on the structure and function of the left ventricular myocardium that may be prognostically important. Here, we review the molecular and in vivo evidence that underpins current knowledge regarding the effects of human or experimental AF on the ventricular myocardium. Potential mechanisms are explored including diffuse ventricular fibrosis, focal myocardial scarring, and impaired myocardial perfusion and perfusion reserve. The complex relationship between AF, systemic inflammation, as well as endothelial/microvascular dysfunction and the effects of AF on ventricular calcium handling and oxidative stress are also addressed. Finally, consideration is given to the clinical implications of these observations and concepts, with particular reference to rate vs. rhythm control.

  20. Ventricular Fibrillation in Mammalian Hearts: Simulation Results

    Science.gov (United States)

    Fenton, Flavio H.

    2002-03-01

    The computational approach to understanding the initiation and evolution of cardiac arrhythmias forms a necessary link between experiment and theory. Numerical simulations combine useful mathematical models and complex geometry while offering clean and comprehensive data acquisition, reproducible results that can be compared to experiments, and the flexibility of exploring parameter space systematically. However, because cardiac dynamics occurs on many scales (on the order of 10^9 cells of size 10-100 microns with more than 40 ionic currents and time scales as fast as 0.01ms), roughly 10^17 operations are required to simulate just one second of real time. These intense computational requirements lead to significant implementation challenges even on existing supercomputers. Nevertheless, progress over the last decade in understanding the effects of some spatial scales and spatio-temporal dynamics on cardiac cell and tissue behavior justifies the use of certain simplifications which, along with improved models for cellular dynamics and detailed digital models of cardiac anatomy, are allowing simulation studies of full-size ventricles and atria. We describe this simulation problem from a combined numerical, physical and biological point of view, with an emphasis on the dynamics and stability of scroll waves of electrical activity in mammalian hearts and their relation to tachycardia, fibrillation and sudden death. Detailed simulations of electrical activity in ventricles including complex anatomy, anisotropic fiber structure, and electrophysiological effects of two drugs (DAM and CytoD) are presented and compared with experimental results.

  1. Short dynamic fibrils in sunspot chromospheres

    CERN Document Server

    van der Voort, Luc Rouppe

    2013-01-01

    Sunspot chromospheres display vigorous oscillatory signature when observed in chromospheric diagnostics like the strong Ca II lines and H-alpha. New high-resolution sunspot observations from the Swedish 1-m Solar Telescope show the ubiquitous presence of small-scale periodic jet-like features that move up and down. This phenomenon has not been described before. Their typical width is about 0.3 arcsec and they display clear parabolic trajectories in space-time diagrams. The maximum extension of the top of the jets is lowest in the umbra, a few 100 km, and progressively longer further away from the umbra in the penumbra, with the longest more than 1000 km. These jets resemble dynamic fibrils found in plage regions but at smaller extensions. LTE inversion of spectro-polarimetric Ca II 8542 observations enabled for a comparison of the magnetic field inclination and the properties of these short jets. We find that the most extended of these jets also have longer periods and tend to be located in regions with more ...

  2. The mechanisms of atrial fibrillation in hyperthyroidism

    Directory of Open Access Journals (Sweden)

    Bielecka-Dabrowa Agata

    2009-04-01

    Full Text Available Abstract Atrial fibrillation (AF is a complex condition with several possible contributing factors. The rapid and irregular heartbeat produced by AF increases the risk of blood clot formation inside the heart. These clots may eventually become dislodged, causing embolism, stroke and other disorders. AF occurs in up to 15% of patients with hyperthyroidism compared to 4% of people in the general population and is more common in men and in patients with triiodothyronine (T3 toxicosis. The incidence of AF increases with advancing age. Also, subclinical hyperthyroidism is a risk factor associated with a 3-fold increase in development of AF. Thyrotoxicosis exerts marked influences on electrical impulse generation (chronotropic effect and conduction (dromotropic effect. Several potential mechanisms could be invoked for the effect of thyroid hormones on AF risk, including elevation of left atrial pressure secondary to increased left ventricular mass and impaired ventricular relaxation, ischemia resulting from increased resting heart rate, and increased atrial eopic activity. Reentry has been postulated as one of the main mechanisms leading to AF. AF is more likely if effective refractory periods are short and conduction is slow. Hyperthyroidism is associated with shortening of action potential duration which may also contribute to AF.

  3. Defibrillation for Ventricular Fibrillation: A Shocking Update.

    Science.gov (United States)

    Nichol, Graham; Sayre, Michael R; Guerra, Federico; Poole, Jeanne

    2017-09-19

    Cardiac arrest is defined as the termination of cardiac activity associated with loss of consciousness, of spontaneous breathing, and of circulation. Sudden cardiac arrest and sudden cardiac death (SCD) are terms often used interchangeably. Most patients with out-of-hospital cardiac arrest have shown coronary artery disease or symptoms during the hour before the event. Cardiac arrest is potentially reversible by cardiopulmonary resuscitation, defibrillation, cardioversion, cardiac pacing, or treatments targeted at the underlying disease (e.g., acute coronary occlusion). We restrict SCD hereafter to cardiac arrest due to ventricular fibrillation, including rhythms shockable by an automatic external defibrillator (AED), implantable cardioverter-defibrillator (ICD), or wearable cardioverter-defibrillator (WCD). We summarize the state of the art related to defibrillation in treating SCD, including a brief history of the evolution of defibrillation, technical characteristics of modern AEDs, strategies to improve AED access and increase survival, ancillary treatments, and use of ICDs or WCDs. Copyright © 2017 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

  4. Wool fibril sponges with perspective biomedical applications.

    Science.gov (United States)

    Patrucco, A; Cristofaro, F; Simionati, M; Zoccola, M; Bruni, G; Fassina, L; Visai, L; Magenes, G; Mossotti, R; Montarsolo, A; Tonin, C

    2016-04-01

    Sheep's wool was used as a natural source to prepare keratin microfibril sponges for scaffolding, by disruption of the histological structure of the fibres through mild alkali treatment, followed by ultrasonication, casting and salt-leaching. The wool sponges showed highly interconnected porosity (93%) and contain intrinsic sites of cellular recognition that mimic the extracellular matrix (ECM). They displayed good thermal and water stability due to the conversion of disulphide cystine bonds into shorter monosulphide lanthionine intermolecular bonds, but significantly swelled in water, because of the high hydrophilicity and porosity, with a volume increasing up to 38%. Nevertheless, sponges were stable in water without structural changes, with a neutral pH in aqueous media, and showed excellent resilience to repeated compression stresses. According to in vitro biocompatibility assays, wool fibril sponges showed a good cell adhesion and proliferation as proved by MTT, FDA assays and SEM observations. The unique structure of the cortical cell network made by wool keratin proteins with controlled-size macro-porosity suitable for cell guesting, and nutrient feeding, provides an excellent scaffold for future tissue engineering applications.

  5. [Metabolic syndrome and chronic persistent atrial fibrillation].

    Science.gov (United States)

    Onuchina, E L; Solov'ev, O V; Mochalova, O V; Kononov, S K; Onuchin, S G

    2011-01-01

    The aim of the study was to elucidate specific features of chronic recurrent atrial fibrillation (AF) in patients with metabolic syndrome (MS) and disturbed carbohydrate metabolism compared with AF patients without MS. It enrolled 145 patients aged 44-83 years: 117 with abdominal obesity (BMI >30 kg/m2, waist circumference >80 and 94 cm in women and men respectively) including 30 without metabolic disturbances; 35 with impaired glucose tolerance (IGT), 52 with type 2 DM, and 28 controls without MS. Parameters measured included frequency and severity of AF, carbohydrate and lipid metabolism, albuminurea, C-reactive peptide level, quality of AH control, results of echocardiography and 24 hour ECG monitoring (sinus rhythm), and insulin resistance index (HOMA IRindex). Groups of AF and MS patients were dominated by women. The frequency and severity of AF relapses in MS patients were higher than in controls (especially in the presence of IGT and DM). IGT and DM2 associated with structural changes in myocardium (left atrial dilatation, prevalence of LV concentric hypertrophy, diastolic dysfunction) coupled to higher systolic AH and marked metabolic disorders (hyperglycemia, IR, elevated microalbuminurea and C-reactive protein level, dyslipidemia). These conditions contribute to the frequency and severity of AF relapses. Development of AF in MS is a multifactor problem necessitating strict control of AH, dyslipidemia, DM2 and IGT, reduction of body weight and abdominal obesity.

  6. Ventricular fibrillation time constant for swine.

    Science.gov (United States)

    Wu, Jiun-Yan; Nimunkar, Amit J; Sun, Hongyu; O'Rourke, Ann; Huebner, Shane; Will, James A; Webster, John G

    2008-10-01

    The strength-duration curve for cardiac excitation can be modeled by a parallel resistor-capacitor circuit that has a time constant. Experiments on six pigs were performed by delivering current from the X26 Taser dart at a distance from the heart to cause ventricular fibrillation (VF). The X26 Taser is an electromuscular incapacitation device (EMD), which generates about 50 kV and delivers a pulse train of about 15-19 pulses s(-1) with a pulse duration of about 150 micros and peak current about 2 A. Similarly a continuous 60 Hz alternating current of the amplitude required to cause VF was delivered from the same distance. The average current and duration of the current pulse were estimated in both sets of experiments. The strength-duration equation was solved to yield an average time constant of 2.87 ms +/- 1.90 (SD). Results obtained may help in the development of safety standards for future electromuscular incapacitation devices (EMDs) without requiring additional animal tests.

  7. Atrial fibrillation and risk of stroke

    DEFF Research Database (Denmark)

    Christiansen, Christine Benn; Gerds, Thomas A; Olesen, Jonas Bjerring

    2016-01-01

    /TE/TIA) in the presence of concomitant stroke risk factors. METHODS AND RESULTS: From nationwide registries, all persons who turned 50, 60, 70, or 80 from 1997 to 2011 were identified. Persons receiving warfarin were excluded. The absolute risk of stroke/TE/TIA was reported for a 5-year period, as was the absolute risk......AIM: Although the relation between stroke risk factors and stroke in patients with atrial fibrillation (AF) has been extensively examined, only few studies have explored the association of AF and the risk of ischaemic stroke/systemic thromboembolism/transient ischaemic attack (stroke...... ratios for AF vs. no AF according to prior stroke and the number of additional risk factors. The study cohort comprised of 3 076 355 persons without AF and 48 189 with AF. For men aged 50 years, with no risk factors, the 5-year risk of stroke was 1.1% (95% confidence interval 1.1-1.1); with AF alone 2...

  8. Evaluative wissenschaftliche Begleitforschung zur Nutzung des Computers im Kunstunterricht. Forschungsdesign, methodologische und methodische Aspekte einer qualitativ empirischen Längsschnittstudie

    Directory of Open Access Journals (Sweden)

    Michael Schacht

    2002-04-01

    Full Text Available In den kommenden Jahren werden verstärkt empirische Studien und deren Ergebnisse nicht nur die Bildungspolitik, sondern auch Schule und Unterricht selbst beeinflussen. Eine Herausforderung lautet hierbei, empirische Forschungsverfahren zu entwickeln und anzuwenden, die es ermöglichen, Wirkungen von Medienpädagogik und ästhetischer Erziehung zu beobachten und festzustellen. Diese Wirkungsforschung kann daraufhin pädagogisch-didaktisches Handeln verändern. Vor diesem Hintergrund wird die Konzeption einer dreijährigen Wissenschaftlichen Begleitforschung dargestellt, die sich u.a. zur Aufgabe macht, die Implementierung des Digitalen in den schulischen Kunstunterricht zu untersuchen. Vorgestellt und diskutiert werden ein exemplarischer Forschungsverlauf sowie Formen der Vermittlung von Forschungsergebnissen an die projektbeteiligten Lehrerinnen und Lehrer.

  9. Faszination einer Kindsmörderin. Medea im 20. Jahrhundert Fascinated by a Child Murderer. Medea in the Twentieth Century

    Directory of Open Access Journals (Sweden)

    Barbara Feichtinger

    2007-03-01

    Full Text Available Die Berliner Literaturwissenschaftlerin Inge Stephan interpretiert ein beeindruckendes Panorama von Medea-Bearbeitungen in Literatur, bildender Kunst, Film und Musik. Sie spürt in ihrem Buch zur Medea-Rezeption im 20. Jh. in höchst differenzierter und anregender Weise den vielfältigen künstlerischen Auseinandersetzungen der Moderne mit einer in vieler Hinsicht provozierenden Frauengestalt der Antike nach.The Berlin-based literary scholar Inge Stephan interprets an impressive panorama of the treatments of Medea in literature, the visual arts, film, and music. In her book on Medea reception in the twentieth century, Stephan traces the numerous modern artistic approaches to this quite provocative female figure of antiquity in a highly differentiated and thought-provoking manner.

  10. Radioiodine therapy in veterinary medicine: treatment of hyperthyroidism in a cat; Die Radioiodtherapie in der Veterinaermedizin: Behandlung der Schilddruesenueberfunktion bei einer Katze

    Energy Technology Data Exchange (ETDEWEB)

    Reinartz, P.; Sabri, O.; Zimny, M.; Buell, U. [Technische Hochschule Aachen (Germany). Klinik fuer Nuklearmedizin; Kinzel, S.; Kuepper, W. [Technische Hochschule Aachen (Germany). Inst. fuer Versuchstierkunde; Bachmann, T. [Tierarztpraxis Dr. med. vet. Thomas Bachmann, Glashhuetten (Germany)

    1999-06-01

    A nine-year-old cat with symptoms of a distinct hyperthyroidism was presented at the University Hospital of the RWTH Aachen. The clinical symptoms as well as the diagnostic procedures performed at the hospital confirmed the diagnosis. After five weeks of thyreostatic medication a regular metabolism of the thyroid gland was established, followed by a radioiodine therapy with 70.3 MBq 131-iodine. Subsequently, the cat was hospitalized for two days before it could be released in good condition. Six weeks after treatment the former drastically reduced weight of the cat recovered to near normal. Even though the chemical analysis detected a discrete hyperthyroidism, clinical symptoms were no longer prominent. Three months after treatment, the final examination showed a regular metabolism of the thyroid gland without a specific thyroidal medication. The presented case illustrates that radioiodine therapy is a safe and efficient treatment of thyroidal dysfunctions in veterinary medicine. (orig.) [Deutsch] Eine neun Jahre alte, europaeische Langhaarkatze wurde mit Symptomen einer ausgepraegten Schilddruesenueberfunktion im Universitaetsklinikum der RWTH Aachen vorgestellt. Sowohl die klinische Symptomatik als auch die Labordiagnostik und die apparativ erhobenen Befunde belegten das Vorliegen einer Hyperthyreose. Im Anschluss an eine fuenfwoechige thyreostatische Therapie, mit der eine euthyreote Stoffwechsellage erreicht werden konnte, wurde eine Radioiodtherapie mit 70,3 MBq 131-Iod durchgefuehrt. Nach einer nur zweitaegigen komplikationslosen Hospitalisierung konnte die Katze in gutem Allgemeinzustand entlassen werden. Sechs Wochen nach der Therapie hatte sich das zuvor deutlich reduzierte Koerpergewicht auf nahezu normgerechte Werte erhoeht; klinische Symptome der Schilddruesenueberfunktion liessen sich trotz einer laborchemisch diagnostizierten diskreten Gesamtthyroxiderhoehung nicht mehr nachweisen. Bei einer abschliessenden Kontrolle drei Monate nach Entlassung wies

  11. Gebrauch von Komplementärmedizin bei Patienten mit metastasierendem Melanom unter Therapie mit Ipilimumab innerhalb einer klinischen Studie.

    Science.gov (United States)

    Huebner, Jutta; Mohr, Peter; Simon, Jan-Christoph; Fluck, Michael; Berking, Carola; Zimmer, Lisa; Loquai, Carmen

    2016-05-01

    In Deutschland wenden 40-90 % aller Krebspatienten Methoden der komplementären and alternativen Medizin (KAM) an. Bis dato gibt es kein Datenmaterial zum Einsatz der KAM bei Melanompatienten. Das Ziel unserer Studie war es, Daten über den Gebrauch, die Informationsquellen und Ziele von Patienten mit metastasierendem Melanom zu erfassen. Einhundertsechsundfünfzig Patienten aus 25 Studienzentren nahmen an der DecOG-MM-PAL Multibasket Studie teil. Die beteiligten Personen wurden auch gebeten, an einer Nebenstudie teilzunehmen, die ihren Gebrauch von KAM erfassen sollte. Dazu wurde während der Behandlung ein standardisierter Fragebogen zu genau festgelegten Zeitpunkten ausgeteilt. Insgesamt gingen 55 Fragebögen von 32 (21 %) Melanompatienten ein. Von diesen gaben 17 (53 %) ein Interesse an KAM an, und sieben (22 %) machten von KAM Gebrauch. Die Hauptinformationsquellen (31 %) waren Familienmitglieder und Freunde, gefolgt von Ärzten (19 %). Die Hauptgründe für die Anwendung von KAM waren die Stärkung des Immunsystems (41 %) und des Körpers (34 %). Nahrungsergänzungsmittel (Vitamine und Spurenelemente) wurden am häufigsten angewendet (28 %). Eine relativ hohe Anzahl an Patienten mit metastasierendem Melanom machte trotz Teilnahme an einer klinischen Studie von KAM Gebrauch. Wechselwirkungen könnten durch biologisch basierte KAM auftreten, und hier besonders bei immunmodulierenden KAM- Strategien. Um Risiken zu vermeiden, sollte die Kommunikation zwischen den Ärzten und den Patienten verbessert werden. © 2016 Deutsche Dermatologische Gesellschaft (DDG). Published by John Wiley & Sons Ltd.

  12. Komplette Revaskularisation am schlagenden Herzen bei Patienten mit koronarer Mehrgefäßerkrankung: Stellenwert einer neuen Operationstechnik

    Directory of Open Access Journals (Sweden)

    Czerny M

    2000-01-01

    Full Text Available Ziel der Studie: Die komplette Revaskularisation am schlagenden Herzen ohne Herz-Lungenmaschine (HLM wird an einer immer größer werdenden Anzahl von Patienten durchgeführt. Klare Vorteile dieser Methode, elektive Patienten mit einem niedrigen Risikoprofil ohne HLM zu operieren, sind bis jetzt nicht nachgewiesen. Material und Methoden: 40 elektive Patienten mit einem niedrigen Risikoprofil wurden in diese Studie eingeschlossen. Anhand der präoperativen Koronarangiographie wurde zunächst beurteilt, ob die komplette Revaskularisation am schlagenden Herzen ohne HLM technisch durchführbar ist. Die Machbarkeit, klinische Ergebnisse und eine wiederauftretende Angina pectoris-Symptomatik wurden neben akkuratem Monitoring klinischer Parameter evaluiert. Der mittlere Nachbeobachtungszeitraum betrug 13,4 ± 6,5 Monate. Ergebnisse: Nur 26 der 40 Patienten konnten am schlagenden Herzen ohne HLM komplett revaskularisiert werden (65 %. 5 Patienten (12,5 % wurden inkomplett revaskularisiert und bei 9 Patienten (22,5 % wurde intraoperativ die HLM doch angewendet. Kein Patient ist verstorben. Es trat kein Myokardinfarkt auf. Alle Patienten blieben während des gesamten Nachbeobachtungszeitraums asymptomatisch. Schlußfolgerungen: Die komplette Revaskularisation am schlagenden Herzen ohne HLM bei Patienten mit Mehrgefäßerkrankungen ist mit exzellenten Kurz- und Langzeitergebnissen durchführbar, läßt sich jedoch in einer geringeren Patientenzahl durchführen, als man das anhand der präoperativen Koronarangiographie annehmen könnte. Es ließ sich kein klarer Vorteil dieser Operationsmethode bei elektiven Patienten mit einem niedrigen Risikoprofil herausarbeiten.

  13. Patient preferences at ten years following initial diagnosis of atrial fibrillation: the Belgrade Atrial Fibrillation Study

    Directory of Open Access Journals (Sweden)

    Potpara TS

    2013-08-01

    Full Text Available Tatjana S Potpara,1,2 Marija M Polovina,2 Nebojsa M Mujovic,1,2 Aleksandar M Kocijancic,2 Gregory YH Lip3 1Faculty of Medicine, University of Belgrade, 2Cardiology Clinic, Clinical Center of Serbia, Belgrade, Serbia; 3University of Birmingham Centre for Cardiovascular Sciences, City Hospital, Birmingham, UK Background: Many atrial fibrillation (AF patients have a poor understanding of the management of this condition. We investigated patient attitudes towards AF and a potential invasive treatment following an average 10-year period of prospective rhythm control in a cohort of newly diagnosed AF patients. Methods: This was a prospective registry-based study. At the regular annual visit in 2007, patients were asked at random to answer several AF-related questions. Results: Of 390 patients, 277 (71.0% reported symptom reduction over time, but only 45 (11.5% reported that they had "got used" to AF; 201 patients (51.5% stated they would always prefer sinus rhythm, and 280 (71.2% would accept an invasive AF treatment. Independent predictors for choosing an invasive procedure were younger age, impaired career/working capacity, and male gender (all P < 0.05. Conclusion: Our findings suggest that most AF patients prefer sinus rhythm and would readily accept an invasive procedure if it offered the possibility of a cure for their AF. Keywords: atrial fibrillation, catheter ablation, treatment, symptoms, patient preferences

  14. Avoiding medical error during electrical cardioversion of atrial fibrillation: prevention of unsynchronized shock delivery.

    Science.gov (United States)

    Estrada, Amara H; Pariaut, Romain; Moïse, N Sydney

    2009-12-01

    Electrical cardioversion of atrial fibrillation is now commonly performed in veterinary medicine. Successful timing of the delivery of energy is important in order to avoid ventricular fibrillation. This brief communication describes how to ensure that proper energy delivery is performed.

  15. 78 FR 11207 - Clinical Study Designs for Surgical Ablation Devices for Treatment of Atrial Fibrillation...

    Science.gov (United States)

    2013-02-15

    ... Treatment of Atrial Fibrillation; Guidance for Industry and Food and Drug Administration Staff; Availability... Ablation Devices for Treatment of Atrial Fibrillation.'' This guidance provides FDA's recommendations on clinical trial designs for surgical ablation devices intended for the treatment of atrial...

  16. Continuous vs episodic prophylactic treatment with amiodarone for the prevention of atrial fibrillation : a randomized trial

    NARCIS (Netherlands)

    Ahmed, Sheba; Rienstra, Michiel; Crijns, Harry J. G. M.; Links, Thera P.; Wiesfeld, Ans C. P.; Hillege, Hans L.; Bosker, Hans A.; Lok, Dirk J. A.; Van Veldhuisen, Dirk J.; Van Gelder, Isabelle C.

    2008-01-01

    Context Amiodarone effectively suppresses atrial fibrillation but causes many adverse events. Objective To compare major events in patients randomized to receive episodic amiodarone treatment with those who received continuous amiodarone treatment while still aiming to prevent atrial fibrillation. D

  17. The changing face of glucagon fibrillation: Structural polymorphism and conformational imprinting

    DEFF Research Database (Denmark)

    Pedersen, J.S.; Dikov, D.; Flink, J.L.

    2006-01-01

    /CD spectra depending on salts, glucagon concentration and fibrillation temperature. Apparent fibrillar stability correlates with spectral and kinetic properties; generally, fibrils formed under conditions favourable for rapid fibrillation (ambient temperatures, high glucagon concentration or high salt......We have established a time-resolved fluorescence assay to study fibrillation of the 29 residue peptide hormone glucagon under a variety of different conditions in a high-throughput format. Fibrils formed at pH 2.5 differ in fibrillation kinetics, morphology, thioflavin T staining and FTIR...... concentration) appear less thermostable than those formed under more challenging conditions (high temperatures, low glucagon or low salt concentrations). Properties of preformed fibrils used for seeding are inherited in a prion-like manner. Thus, we conclude that the structure of fibrils formed by glucagon...

  18. Radiofrequency catheter ablation maintains its efficacy better than antiarrhythmic medication in patients with paroxysmal atrial fibrillation

    DEFF Research Database (Denmark)

    Raatikainen, M J Pekka; Hakalahti, Antti; Uusimaa, Paavo;

    2015-01-01

    BACKGROUND: The Medical ANtiarrhythmic Treatment or Radiofrequency Ablation in Paroxysmal Atrial Fibrillation (MANTRA-PAF) is a randomized trial comparing radiofrequency catheter ablation (RFA) to antiarrhythmic drugs (AADs) as first-line treatment of paroxysmal atrial fibrillation (PAF). In order...

  19. Prevalence and risk factors of atrial fibrillation in hospitalized patients with chronic kidney disease

    Institute of Scientific and Technical Information of China (English)

    王骄

    2013-01-01

    Objective Atrial fibrillation (AF) is the most common sustained tachyarrhythmia in the general population.AF and Chronic Kidney Disease (CKD) share several common risk factors.We investigated the association between chronic kidney disease and risk of atrial fibrillation

  20. Spin Labeling and Characterization of Tau Fibrils Using Electron Paramagnetic Resonance (EPR).

    Science.gov (United States)

    Meyer, Virginia; Margittai, Martin

    2016-01-01

    Template-assisted propagation of Tau fibrils is essential for the spreading of Tau pathology in Alzheimer's disease. In this process, small seeds of fibrils recruit Tau monomers onto their ends. The physical properties of the fibrils play an important role in their propagation. Here, we describe two different electron paramagnetic resonance (EPR) techniques that have provided crucial insights into the structure of Tau fibrils. Both techniques rely on the site-directed introduction of one or two spin labels into the protein monomer. Continuous-wave (CW) EPR provides information on which amino acid residues are contained in the fibril core and how they are stacked along the long fibril axis. Double electron-electron resonance (DEER) determines distances between two spin labels within a single protein and hence provides insights into their spatial arrangement in the fibril cross section. Because of the long distance range accessible to DEER (~2-5 nm) populations of distinct fibril conformers can be differentiated.

  1. Risk of atrial fibrillation as a function of the electrocardiographic PR interval

    DEFF Research Database (Denmark)

    Nielsen, Jonas Bille; Pietersen, Adrian; Graff, Claus;

    2013-01-01

    Prolongation of the PR interval has been associated with an increased risk of incident atrial fibrillation (AF).......Prolongation of the PR interval has been associated with an increased risk of incident atrial fibrillation (AF)....

  2. Characterizing Structural Stability of Amyloid Motif Fibrils Mediated by Water Molecules.

    Science.gov (United States)

    Choi, Hyunsung; Chang, Hyun Joon; Lee, Myeongsang; Na, Sungsoo

    2017-02-04

    In biological systems, structural confinements of amyloid fibrils can be mediated by the role of water molecules. However, the underlying effect of the dynamic behavior of water molecules on structural stabilities of amyloid fibrils is still unclear. By performing molecular dynamics simulations, we investigate the dynamic features and the effect of interior water molecules on conformations and mechanical characteristics of various amyloid fibrils. We find that a specific mechanism induced by the dynamic properties of interior water molecules can affect diffusion of water molecules inside amyloid fibrils, inducing their different structural stabilities. The conformation of amyloid fibrils induced by interior water molecules show the fibrils' different mechanical features. We elucidate the role of confined and movable interior water molecules in structural stabilities of various amyloid fibrils. Our results offer insights not only in further understanding of mechanical features of amyloids as mediated by water molecules, but also in the fine-tuning of the functional abilities of amyloid fibrils for applications.

  3. Impaired autonomic function predicts dizziness at onset of paroxysmal atrial fibrillation

    NARCIS (Netherlands)

    van den Berg, MP; Hassink, RJ; Tuinenburg, AE; Lefrandt, JD; de Kam, PJ; Crijns, HJGM

    2001-01-01

    Background: Paroxysmal atrial fibrillation is associated with various symptoms, including dizziness, which presumably reflects hemodynamic deterioration. Given the importance of the autonomic nervous system in mitigating the hemodynamic effect of atrial fibrillation, we hypothesized that autonomic f

  4. Determination of collagen fibril structure and orientation in connective tissues by X-ray diffraction

    Science.gov (United States)

    Wilkinson, S. J.; Hukins, D. W. L.

    1999-08-01

    Elastic scattering of X-rays can provide the following information on the fibrous protein collagen: its molecular structure, the axial arrangement of rod-like collagen molecules in a fibril, the lateral arrangement of molecules within a fibril, and the orientation of fibrils within a biological tissue. The first part of the paper reviews the principles involved in deducing this information. The second part describes a new computer program for measuring the equatorial intensity distribution, that provides information on the lateral arrangement of molecules within a fibril, and the angular distribution of the equatorial peaks that provides information on the orientation of fibrils. Orientation of fibrils within a tissue is quantified by the orientation distribution function, g( φ), which represents the probability of finding a fibril oriented between φ and φ+ δφ. The application of the program is illustrated by measurement of g( φ) for the collagen fibrils in demineralised cortical bone from cow tibia.

  5. On the adsorption of magnetite nanoparticles on lysozyme amyloid fibrils.

    Science.gov (United States)

    Majorosova, Jozefina; Petrenko, Viktor I; Siposova, Katarina; Timko, Milan; Tomasovicova, Natalia; Garamus, Vasil M; Koralewski, Marceli; Avdeev, Mikhail V; Leszczynski, Błażej; Jurga, Stefan; Gazova, Zuzana; Hayryan, Shura; Hu, Chin-Kun; Kopcansky, Peter

    2016-10-01

    An adsorption of magnetic nanoparticles (MNP) from electrostatically stabilized aqueous ferrofluids on amyloid fibrils of hen egg white lysozyme (HEWL) in 2mg/mL acidic dispersions have been detected for the MNP concentration range of 0.01-0.1vol.%. The association of the MNP with amyloid fibrils has been characterized by transmission electron microscopy (TEM), small-angle X-ray scattering (SAXS) and magneto-optical measurements. It has been observed that the extent of adsorption is determined by the MNP concentration. When increasing the MNP concentration the formed aggregates of magnetic particles repeat the general rod-like structure of the fibrils. The effect is not observed when MNP are mixed with the solution of lysozyme monomers. The adsorption has been investigated with the aim to clarify previously found disaggregation activity of MNP in amyloid fibrils dispersions and to get deeper insight into interaction processes between amyloids and MNP. The observed effect is also discussed with respect to potential applications for ordering lysozyme amyloid fibrils in a liquid crystal phase under external magnetic fields.

  6. Amyloid fibrils composed of hexameric peptides attenuate neuroinflammation.

    Science.gov (United States)

    Kurnellas, Michael P; Adams, Chris M; Sobel, Raymond A; Steinman, Lawrence; Rothbard, Jonathan B

    2013-04-03

    The amyloid-forming proteins tau, αB crystallin, and amyloid P protein are all found in lesions of multiple sclerosis (MS). Our previous work established that amyloidogenic peptides from the small heat shock protein αB crystallin (HspB5) and from amyloid β fibrils, characteristic of Alzheimer's disease, were therapeutic in experimental autoimmune encephalomyelitis (EAE), reflecting aspects of the pathology of MS. To understand the molecular basis for the therapeutic effect, we showed a set of amyloidogenic peptides composed of six amino acids, including those from tau, amyloid β A4, major prion protein (PrP), HspB5, amylin, serum amyloid P, and insulin B chain, to be anti-inflammatory and capable of reducing serological levels of interleukin-6 and attenuating paralysis in EAE. The chaperone function of the fibrils correlates with the therapeutic outcome. Fibrils composed of tau 623-628 precipitated 49 plasma proteins, including apolipoprotein B-100, clusterin, transthyretin, and complement C3, supporting the hypothesis that the fibrils are active biological agents. Amyloid fibrils thus may provide benefit in MS and other neuroinflammatory disorders.

  7. Measurement of the Mechanical Properties of Intact Collagen Fibrils

    Science.gov (United States)

    Mercedes, H.; Heim, A.; Matthews, W. G.; Koob, T.

    2006-03-01

    Motivated by the genetic disorder Ehlers-Danlos syndrome (EDS), in which proper collagen synthesis is interrupted, we are investigating the structural and mechanical properties of collagen fibrils. The fibrous glycoprotein collagen is the most abundant protein found in the human body and plays a key role in the extracellular matrix of the connective tissue, the properties of which are altered in EDS. We have selected as our model system the collagen fibrils of the sea cucumber dermis, a naturally mutable tissue. This system allows us to work with native fibrils which have their proteoglycan complement intact, something that is not possible with reconstituted mammalian collagen fibrils. Using atomic force microscopy, we measure, as a function of the concentration of divalent cations, the fibril diameter, its response to force loading, and the changes in its rigidity. Through these experiments, we will shed light on the mechanisms which control the properties of the sea cucumber dermis and hope to help explain the altered connective tissue extracellular matrix properties associated with EDS.

  8. De novo designed peptide-based amyloid fibrils.

    Science.gov (United States)

    López De La Paz, Manuela; Goldie, Kenneth; Zurdo, Jesús; Lacroix, Emmanuel; Dobson, Christopher M; Hoenger, Andreas; Serrano, Luis

    2002-12-10

    Identification of therapeutic strategies to prevent or cure diseases associated with amyloid fibril deposition in tissue (Alzheimer's disease, spongiform encephalopathies, etc.) requires a rational understanding of the driving forces involved in the formation of these organized assemblies rich in beta-sheet structure. To this end, we used a computer-designed algorithm to search for hexapeptide sequences with a high propensity to form homopolymeric beta-sheets. Sequences predicted to be highly favorable on this basis were found experimentally to self-associate efficiently into beta-sheets, whereas point mutations predicted to be unfavorable for this structure inhibited polymerization. However, the property to form polymeric beta-sheets is not a sufficient requirement for fibril formation because, under the conditions used here, preformed beta-sheets from these peptides with charged residues form well defined fibrils only if the total net charge of the molecule is +/-1. This finding illustrates the delicate balance of interactions involved in the formation of fibrils relative to more disordered aggregates. The present results, in conjunction with x-ray fiber diffraction, electron microscopy, and Fourier transform infrared measurements, have allowed us to propose a detailed structural model of the fibrils.

  9. Reversible heat-induced dissociation of β2-microglobulin amyloid fibrils.

    Science.gov (United States)

    Kardos, József; Micsonai, András; Pál-Gábor, Henriett; Petrik, Éva; Gráf, László; Kovács, János; Lee, Young-Ho; Naiki, Hironobu; Goto, Yuji

    2011-04-19

    Recent progress in the field of amyloid research indicates that the classical view of amyloid fibrils, being irreversibly formed highly stable structures resistant to perturbating conditions and proteolytic digestion, is getting more complex. We studied the thermal stability and heat-induced depolymerization of amyloid fibrils of β(2)-microglobulin (β2m), a protein responsible for dialysis-related amyloidosis. We found that freshly polymerized β2m fibrils at 0.1-0.3 mg/mL concentration completely dissociated to monomers upon 10 min incubation at 99 °C. Fibril depolymerization was followed by thioflavin-T fluorescence and circular dichroism spectroscopy at various temperatures. Dissociation of β2m fibrils was found to be a reversible and dynamic process reaching equilibrium between fibrils and monomers within minutes. Repolymerization experiments revealed that the number of extendable fibril ends increased significantly upon incubation at elevated temperatures suggesting that the mechanism of fibril unfolding involves two distinct processes: (1) dissociation of monomers from the fibril ends and (2) the breakage of fibrils. The breakage of fibrils may be an important in vivo factor multiplying the number of fibril nuclei and thus affecting the onset and progress of disease. We investigated the effects of some additives and different factors on the stability of amyloid fibrils. Sample aging increased the thermal stability of β2m fibril solution. 0.5 mM SDS completely prevented β2m fibrils from dissociation up to the applied highest temperature of 99 °C. The generality of our findings was proved on fibrils of K3 peptide and α-synuclein. Our simple method may also be beneficial for screening and developing amyloid-active compounds for therapeutic purposes.

  10. Atrial fibrillation in the elderly: Is ablation ready for prime time?

    Institute of Scientific and Technical Information of China (English)

    Allen J. Solomon

    2005-01-01

    @@ Atrial fibrillation is the most common sustained arrhythmia and results in significant morbidity, especially in the elderly. The prevalence of atrial fibrillation increases dramatically with advancing age to almost 6% in individuals older than 65 years. In fact, 84% of people with atrial fibrillation are over 65 years of age.1 Additionally, the risk of stroke increases with advancing age, such that one-third of strokes in patients over the age of 65 are caused by atrial fibrillation.

  11. Excessive supraventricular ectopic activity and increased risk of atrial fibrillation and stroke

    DEFF Research Database (Denmark)

    Binici, Zeynep; Intzilakis, Theodoros; Wendelboe Nielsen, Olav

    2010-01-01

    Prediction of stroke and atrial fibrillation in healthy individuals is challenging. We examined whether excessive supraventricular ectopic activity (ESVEA) correlates with risk of stroke, death, and atrial fibrillation in subjects without previous stroke or heart disease.......Prediction of stroke and atrial fibrillation in healthy individuals is challenging. We examined whether excessive supraventricular ectopic activity (ESVEA) correlates with risk of stroke, death, and atrial fibrillation in subjects without previous stroke or heart disease....

  12. Endocytosed 2-Microglobulin Amyloid Fibrils Induce Necrosis and Apoptosis of Rabbit Synovial Fibroblasts by Disrupting Endosomal/Lysosomal Membranes: A Novel Mechanism on the Cytotoxicity of Amyloid Fibrils.

    Directory of Open Access Journals (Sweden)

    Tadakazu Okoshi

    Full Text Available Dialysis-related amyloidosis is a major complication in long-term hemodialysis patients. In dialysis-related amyloidosis, β2-microglobulin (β2-m amyloid fibrils deposit in the osteoarticular tissue, leading to carpal tunnel syndrome and destructive arthropathy with cystic bone lesions, but the mechanism by which these amyloid fibrils destruct bone and joint tissue is not fully understood. In this study, we assessed the cytotoxic effect of β2-m amyloid fibrils on the cultured rabbit synovial fibroblasts. Under light microscopy, the cells treated with amyloid fibrils exhibited both necrotic and apoptotic changes, while the cells treated with β2-m monomers and vehicle buffer exhibited no morphological changes. As compared to β2-m monomers and vehicle buffer, β2-m amyloid fibrils significantly reduced cellular viability as measured by the lactate dehydrogenase release assay and the 3-(4,5-di-methylthiazol-2-yl-2,5-diphenyltetrazolium bromide reduction assay and significantly increased the percentage of apoptotic cells as measured by the terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling method. β2-m amyloid fibrils added to the medium adhered to cell surfaces, but did not disrupt artificial plasma membranes as measured by the liposome dye release assay. Interestingly, when the cells were incubated with amyloid fibrils for several hours, many endosomes/lysosomes filled with amyloid fibrils were observed under confocal laser microscopy and electron microscopy, Moreover, some endosomal/lysosomal membranes were disrupted by intravesicular fibrils, leading to the leakage of the fibrils into the cytosol and adjacent to mitochondria. Inhibition of actin-dependent endocytosis by cytochalasin D attenuated the toxicity of amyloid fibrils. These results suggest that endocytosed β2-m amyloid fibrils induce necrosis and apoptosis by disrupting endosomal/lysosomal membranes, and this novel mechanism on the cytotoxicity of amyloid

  13. 77 FR 11121 - Scientific Information Request on Treatment of Atrial Fibrillation

    Science.gov (United States)

    2012-02-24

    ... Atrial Fibrillation AGENCY: Agency for Healthcare Research and Quality (AHRQ), HHS. ACTION: Request for... scientific information submissions from manufacturers of atrial fibrillation medical devices. Scientific... effectiveness review of the evidence for the treatment of atrial fibrillation. The EHC Program is dedicated...

  14. AFM-based force spectroscopy measurements of mature amyloid fibrils of the peptide glucagon

    DEFF Research Database (Denmark)

    Dong, M. D.; Hovgaard, M. B.; Mamdouh, W.;

    2008-01-01

    of such mature fibrils contribute to their high stability, suggesting that the internal hydrophobic interactions of amyloid fibrils are likely to be of fundamental importance in the assembly of amyloid fibrils and therefore for the understanding of the progression of their associated pathogenic disorders...

  15. Causes of deaths and influencing factors in patients with atrial fibrillation

    DEFF Research Database (Denmark)

    Fauchier, Laurent; Villejoubert, Olivier; Clementy, Nicolas;

    2016-01-01

    BACKGROUND: Atrial fibrillation is associated with a higher mortality, but causes of death of atrial fibrillation patients and their specific predictors have been less well defined. We aimed to identify the causes of death among atrial fibrillation patients and secondly, clinical predictors for t...

  16. Meta-analysis identifies six new susceptibility loci for atrial fibrillation

    NARCIS (Netherlands)

    Ellinor, Patrick T; Lunetta, Kathryn L; Albert, Christine M; Glazer, Nicole L; Ritchie, Marylyn D; Smith, Albert V; Arking, Dan E; Müller-Nurasyid, Martina; Krijthe, Bouwe P; Lubitz, Steven A; Bis, Joshua C; Chung, Mina K; Dörr, Marcus; Ozaki, Kouichi; Roberts, Jason D; Smith, J Gustav; Pfeufer, Arne; Sinner, Moritz F; Lohman, Kurt; Ding, Jingzhong; Smith, Nicholas L; Smith, Jonathan D; Rienstra, Michiel; Rice, Kenneth M; Van Wagoner, David R; Magnani, Jared W; Wakili, Reza; Clauss, Sebastian; Rotter, Jerome I; Steinbeck, Gerhard; Launer, Lenore J; Davies, Robert W; Borkovich, Matthew; Harris, Tamara B; Lin, Honghuang; Völker, Uwe; Völzke, Henry; Milan, David J; Hofman, Albert; Boerwinkle, Eric; Chen, Lin Y; Soliman, Elsayed Z; Voight, Benjamin F; Li, Guo; Chakravarti, Aravinda; Kubo, Michiaki; Tedrow, Usha B; Rose, Lynda M; Ridker, Paul M; Conen, David; Tsunoda, Tatsuhiko; Furukawa, Tetsushi; Sotoodehnia, Nona; Xu, Siyan; Kamatani, Naoyuki; Levy, Daniel; Nakamura, Yusuke; Parvez, Babar; Mahida, Saagar; Furie, Karen L; Rosand, Jonathan; Muhammad, Raafia; Psaty, Bruce M; Meitinger, Thomas; Perz, Siegfried; Wichmann, H-Erich; Witteman, Jacqueline C M; Kao, W H Linda; Kathiresan, Sekar; Roden, Dan M; Uitterlinden, Andre G; Rivadeneira, Fernando; McKnight, Barbara; Sjögren, Marketa; Newman, Anne B; Liu, Yongmei; Gollob, Michael H; Melander, Olle; Tanaka, Toshihiro; Stricker, Bruno H Ch; Felix, Stephan B; Alonso, Alvaro; Darbar, Dawood; Barnard, John; Chasman, Daniel I; Heckbert, Susan R; Benjamin, Emelia J; Gudnason, Vilmundur; Kääb, Stefan

    2012-01-01

    Atrial fibrillation is a highly prevalent arrhythmia and a major risk factor for stroke, heart failure and death. We conducted a genome-wide association study (GWAS) in individuals of European ancestry, including 6,707 with and 52,426 without atrial fibrillation. Six new atrial fibrillation suscepti

  17. Spiral CT in aplasia of the pre-renal inferior vena cava as a cause of phlebothrombosis from the femoral veins to the inferior vena cava; Spiral-CT einer Aplasie der praerenalen Vena cava inferior als Ursache einer Phlebothrombose von den Oberschenkelvenen bis in die Vena cava inferior

    Energy Technology Data Exchange (ETDEWEB)

    Schweiger, U. [Strahlenklinik und Poliklinik, Universitaetsklinikum Rudolf Virchow, Freie Univ. Berlin (Germany); Schedel, H. [Strahlenklinik und Poliklinik, Universitaetsklinikum Rudolf Virchow, Freie Univ. Berlin (Germany); Thiede, U. [Deutsches Herzzentrum Berlin (Germany). Arbeitsgruppe Digitale Bildbearbeitung; Felix, R. [Strahlenklinik und Poliklinik, Universitaetsklinikum Rudolf Virchow, Freie Univ. Berlin (Germany)

    1994-12-31

    The case report focuses on the computed tomography of the thrombotic okklusion of the inferior vena cava, venae iliacae and femorales communes due to congenital interruption of the prerenal inferior vena cava. The embryology of the abnormality was discussed. (orig.) [Deutsch] Anhand einer Fallstudie wurden die Moeglichkeiten der computertomographischen Diagnostik bei einer durch Teilplasie der `praerenalen` Vena cava inferior hervorgerufenen Thrombose der Vv. femorales superficiales et profundae, der grossen Beckenvenen und der Vena cava inferior erlaeutert. In der Diskussion wurde auf die Embryologie der Missbildung eingegangen. (orig.)

  18. Dronedarone: an emerging therapy for atrial fibrillation.

    Science.gov (United States)

    Rosei, Enrico Agabiti; Salvetti, Massimo

    2010-06-01

    Atrial fibrillation (AF) is a common arrhythmia, with a prevalence ranging from 0.1% to 9.0% at different ages, and is associated with increased cardiovascular events and mortality. A significant increase in the prevalence of the disease is expected to occur in the coming years as a consequence of the aging of the population and advances in the management of coronary artery disease and heart failure. Effective rhythm control may be difficult to obtain in a significant proportion of patients with AF. The limited efficacy and the possible adverse effects of antiarrhythmic drugs has led researchers to focus their attention on new molecules, in a search of compounds with antiarrhythmic efficacy and a more favourable safety profile. Among several new drugs developed for the management of AF, dronedarone, a benzofuran derivative that shares many of the antiarrhythmic properties of amiodarone, but with a more favourable safety profile, seems particularly promising. The drug is noniodinated, has less lipophilicity, reaches therapeutic concentrations over a shorter period of time and has lower tissue accumulation. Dronedarone, similarly to amiodarone, exhibits electrophysiologic characteristics of all 4 Vaughan Williams classes. Clinical studies have shown that dronedarone effectively reduces ventricular rate, may prevent or delay the recurrence of AF, and may reduce cardiovascular morbidity and mortality in patients with AF or atrial flutter. The drug has an overall good safety profile, in particular with low pulmonary and thyroid toxicity. An important exception is represented by patients with unstable haemodynamic conditions, in which the use of dronedarone has been found to be associated with an increase in mortality. Dronedarone has been recently approved for clinical use by the Food and Drug Administration and by the European Medicines Agency. Further results from trials and clinical use will better define the efficacy and safety profile of dronedarone in AF compared

  19. The atrial fibrillation conundrum in dialysis patients.

    Science.gov (United States)

    De Vriese, An S; Caluwé, Rogier; Raggi, Paolo

    2016-04-01

    The burden of atrial fibrillation (AF) and the risk of stroke are high in dialysis patients. The decision to use anticoagulation rests heavily on effective risk stratification. Because both the pathophysiology of the disease and the response to therapy differ in dialysis, data from the general population cannot be extrapolated. The effect of vitamin K antagonists (VKAs) on the risk of stroke in dialysis patients with AF has not been studied in randomized trials. The available observational data provide contradictory results, reflecting differences in the degree of residual confounding, quality of international normalized ratio control, and stroke characterization. Dialysis patients have a high baseline bleeding risk. It remains unclear to what extent VKAs affect the overall bleeding propensity, but they may significantly increase the risk of intracerebral hemorrhage. Vascular calcifications are extremely prevalent in dialysis patients and independently associated with an adverse outcome. Vitamin K antagonists inhibit the activity of key anticalcifying proteins and may thus compound the risk of vascular calcification progression in dialysis. In the absence of evidence-based guidelines for anticoagulation in dialysis patients with AF, we provide recommendations to assist clinicians in individualized risk stratification. We further propose that new oral anticoagulants may have a better benefit-risk profile in dialysis patients than VKA, provided appropriate dose reductions are made. New oral anticoagulant may yield more on-target anticoagulation, reduce the risk of intracerebral bleeding, and not interfere with vascular calcification biology. Clinical trials with new oral anticoagulant in dialysis patients are eagerly awaited, to reveal whether these assumptions can be confirmed.

  20. Left atrium segmentation for atrial fibrillation ablation

    Science.gov (United States)

    Karim, R.; Mohiaddin, R.; Rueckert, D.

    2008-03-01

    Segmentation of the left atrium is vital for pre-operative assessment of its anatomy in radio-frequency catheter ablation (RFCA) surgery. RFCA is commonly used for treating atrial fibrillation. In this paper we present an semi-automatic approach for segmenting the left atrium and the pulmonary veins from MR angiography (MRA) data sets. We also present an automatic approach for further subdividing the segmented atrium into the atrium body and the pulmonary veins. The segmentation algorithm is based on the notion that in MRA the atrium becomes connected to surrounding structures via partial volume affected voxels and narrow vessels, the atrium can be separated if these regions are characterized and identified. The blood pool, obtained by subtracting the pre- and post-contrast scans, is first segmented using a region-growing approach. The segmented blood pool is then subdivided into disjoint subdivisions based on its Euclidean distance transform. These subdivisions are then merged automatically starting from a seed point and stopping at points where the atrium leaks into a neighbouring structure. The resulting merged subdivisions produce the segmented atrium. Measuring the size of the pulmonary vein ostium is vital for selecting the optimal Lasso catheter diameter. We present a second technique for automatically identifying the atrium body from segmented left atrium images. The separating surface between the atrium body and the pulmonary veins gives the ostia locations and can play an important role in measuring their diameters. The technique relies on evolving interfaces modelled using level sets. Results have been presented on 20 patient MRA datasets.

  1. Impaired endothelial function in lone atrial fibrillation

    Directory of Open Access Journals (Sweden)

    Polovina Marija

    2013-01-01

    Full Text Available Background/Aim. Impaired endothelial function has been previously documented in patients with atrial fibrillation (AF and underlying comorbidities or older patients with idiopathic AF. The aim of this study was to evaluate systemic endothelial function in younger AF patients (less than 7 days lone AF. The second group comprised of 28 healthy controls in sinus rhythm (the mean age 43 ± 13, 53% male, matched by age, gender and atherosclerotic risk factors. All the participants underwent physical examination, laboratory analysis [including determination of C-reactive protein (CRP], standard echocardiography and exercise-stress testing. Brachial artery FMD and endothelium independent dilation (NMD were assessed with a high-resolution ultrasound probe and arterial diameters taken from 5 consecutive cardiac cycles were averaged for each measurement to accommodate to beat-to-beat flow variations in AF. Results. There were no differences between the 2 groups regarding age, gender and most clinical, laboratory and echocardiographic characteristics (all p > 0.05, apart from the increased heart rate (p = 0.018, body mass index (p = 0.027, CRP levels (p = 0.007 and left atrial anteroposterior dimension (p 0.05. In the multivariate analysis, the independent FMD determinants in our study population were the presence of AF, smoking and total cholesterol levels (all p < 0.001. In patients with AF, the strongest independent FMD determinant was arrhythmia duration (p < 0.001, followed by smoking (p = 0.013 and total cholesterol levels (p = 0.045. Conclusions. Our findings confirm that sustained AF is associated with systemic endothelial dysfunction even in relatively young patients with no cardiovascular disorders or risk factors. AF is an independent contributor to lower FMD and a prolonged arrhythmia duration may confer the risk for more profound endothelial damage.

  2. A quantitative measurement of spatial order in ventricular fibrillation

    CERN Document Server

    Bayly, P V; Wolf, P D; Greenside, H S; Smith, W M; Ideker, R E

    1993-01-01

    As an objective measurement of spatial order in ventricular fibrillation (VF), spatial correlation functions and their characteristic lengths were estimated from epicardial electrograms of pigs in VF. The correlation length of the VF in pigs was found to be approximately 4-10 mm, varying as fibrillation progressed. The degree of correlation decreased in the first 4 seconds after fibrillation then increased over the next minute. The correlation length is much smaller than the scale of the heart, suggesting that many independent regions of activity exist on the epicardium at any one time. On the other hand, the correlation length is 4 to 10 times the interelectrode spacing, indicating that some coherence is present. These results imply that the heart behaves during VF as a high-dimensional, but not random, system involving many spatial degrees of freedom, which may explain the lack of convergence of fractal dimension estimates reported in the literature. Changes in the correlation length also suggest that VF re...

  3. Molecular packing in bone collagen fibrils prior to mineralization

    Science.gov (United States)

    Hsiao, Benjamin; Zhou, Hong-Wen; Burger, Christian; Chu, Benjamin; Glimcher, Melvin J.

    2012-02-01

    The three-dimensional packing of collagen molecules in bone collagen fibrils has been largely unknown because even in moderately mineralized bone tissues, the organic matrix structure is severely perturbed by the deposition of mineral crystals. During the past decades, the structure of tendon collagen (e.g. rat tail) --- a tissue that cannot mineralize in vivo, has been assumed to be representative for bone collagen fibrils. Small-angle X-ray diffraction analysis of the native, uncalcified intramuscular fish bone has revealed a new molecular packing scheme, significantly different from the quasi-hexagonal arrangement often found in tendons. The deduced structure in bone collagen fibrils indicates the presence of spatially discrete microfibrils, and an arrangement of intrafibrillar space to form ``channels'', which could accommodate crystals with dimensions typically found in bone apatite.

  4. Binuclear ruthenium(II) complexes for amyloid fibrils recognition

    Energy Technology Data Exchange (ETDEWEB)

    Hanczyc, Piotr, E-mail: piotr.hanczyc@chalmers.se

    2014-12-05

    Highlights: • Interactions of binuclear ruthenium(II) complexes with amyloid fibrils. • Dimer ruthenium(II) compounds are sensitive amyloid fibrils biomarkers. • Recognition of amyloid-chromophore adducts by two-photon excited emission. - Abstract: Metal–organic compounds represent a unique class of biomarkers with promising photophysical properties useful for imaging. Here interactions of insulin fibrils with two binuclear complexes [μ-(11,11′-bidppz)(phen){sub 4}Ru{sub 2}]{sup 4+} (1) and [μ-C4(cpdppz)(phen){sub 4}Ru{sub 2}]{sup 4+} (2) are studied by linear dichroism (LD) and fluorescence. These ruthenium(II) compounds could provide a new generation of amyloid binding chromophores with long lived lifetimes, good luminescence quantum yields for the bound molecules and photo-stability useful in multiphoton luminescence imaging.

  5. Control the kinetics and pathway of insulin fibril formation

    Science.gov (United States)

    Zheng, Zhongli; Jing, Benxin; Zhu, Y. Elaine

    2012-02-01

    Protein fibrils have been proposed as possible toxic agents for many amyloid related diseases, such as Alzheimer's disease, however the reaction pathway toward the amyloid fibrillation remain inadequately understood. In this work, we examine the conformational transition of human insulin as the model amyloid protein by single-molecule fluorescence spectroscopy and imaging. By controlling the pH cycling, insulin monomer and oligomers are indentified at given pH variation condition. Furthermore, low frequency ac-electric fields are employed to control the insulin aggregation from its monomers in a microchannel. It is observed that lag time to induce insulin fibrillation can be significantly shortened, in compassion to the commonly used cooling and seeding methods, and exhibits a strong dependence on applied ac-field strength. Additionally, the structure of insulin aggregates under ac-electric fields is observed to be drastically different from that under the temperature control.

  6. Wie kann man komplexe Themen wie Globalisierung oder europäische Integration unterrichten?

    OpenAIRE

    Müller, Ragnar

    2006-01-01

    Die Dissertation zeigt die Vermittlungsprobleme auf, die sich in der politischen Bildung bei komplexen Themen wie Globalisierung oder europäischer Integration stellen, und stellt einen neuen politikdidaktischen Ansatz zur Diskussion, der Politikverständnis in einer globalisierten Welt erreichen will. The Thesis analyses the problems of teaching complex political topics such as globalisation and European integration and presents a new approach to teaching politics in a globalized world.

  7. Ventricular rate control of atrial fibrillation in heart failure.

    Science.gov (United States)

    Rienstra, Michiel; Van Gelder, Isabelle C

    2013-10-01

    In the last few years, there has been a major shift in the treatment of atrial fibrillation (AF) in the setting of hear failure (HF), from rhythm to ventricular rate control in most patients with both conditions. In this article, the authors focus on ventricular rate control and discuss the indications; the optimal ventricular rate-control target, including detailed results of the Rate Control Efficacy in Permanent Atrial Fibrillation: a Comparison Between Lenient versus Strict Rate Control II (RACE II) study; and the pharmacologic and nonpharmacologic options to control the ventricular rate during AF in the setting of HF.

  8. Antiarrhythmic Effect Of Antioxidants In Patients With Atrial Fibrillation.

    Science.gov (United States)

    Khabchabov PhD, Rustam; Rg PhD, Khabchabov; Er PhD, Makhmudova

    2016-01-01

    Resume In accordance with modern concepts, one of the leading roles in the development of paroxysmal atrial fibrillation and flutter, belongs - the restructuring of the myocardium, in second place - sick sinus syndrome and in third place - the presence of accessory pathways and hormonal disorders. The development of atrial fibrillation and flutter in the structural pathology, primarily begins with of drugs if it does not work, we have to carry out ablation. Providing proper, effective and important combination therapy - is the main challenge in cardiology.

  9. Kink waves in an active region dynamic fibril

    CERN Document Server

    Pietarila, A; Hirzberger, J; Solanki, S K

    2011-01-01

    We present high spatial and temporal resolution Ca II 8542 observations of a kink wave in an on-disk chromospheric active region fibril. The properties of the wave are similar to those observed in off-limb spicules. From the observed phase and period of the wave we determine a lower limit for the field strength in the chromospheric active region fibril located at the edge of a sunspot to be a few hundred Gauss. We find indications that the event was triggered by a small-scale reconnection event higher up in the atmosphere.

  10. Kink Waves in an Active Region Dynamic Fibril

    Science.gov (United States)

    Pietarila, A.; Aznar Cuadrado, R.; Hirzberger, J.; Solanki, S. K.

    2011-10-01

    We present high spatial and temporal resolution Ca II 8542 Å observations of a kink wave in an on-disk chromospheric active region fibril. The properties of the wave are similar to those observed in off-limb spicules. From the observed phase and period of the wave we determine a lower limit for the field strength in the chromospheric active region fibril located at the edge of a sunspot to be a few hundred gauss. We find indications that the event was triggered by a small-scale reconnection event higher up in the atmosphere.

  11. Macromolecular crowding for tailoring tissue-derived fibrillated matrices.

    Science.gov (United States)

    Magno, Valentina; Friedrichs, Jens; Weber, Heather M; Prewitz, Marina C; Tsurkan, Mikhail V; Werner, Carsten

    2017-06-01

    Tissue-derived fibrillated matrices can be instrumental for the in vitro reconstitution of multiphasic extracellular microenvironments. However, despite of several advantages, the obtained scaffolds so far offer a rather narrow range of materials characteristics only. In this work, we demonstrate how macromolecular crowding (MMC) - the supplementation of matrix reconstitution media with synthetic or natural macromolecules in ways to create excluded volume effects (EVE) - can be employed for tailoring important structural and biophysical characteristics of kidney-derived fibrillated matrices. Porcine kidneys were decellularized, ground and the obtained extracellular matrix (ECM) preparations were reconstituted under varied MMC conditions. We show that MMC strongly influences the fibrillogenesis kinetics and impacts the architecture and the elastic modulus of the reconstituted matrices, with diameters and relative alignment of fibrils increasing at elevated concentrations of the crowding agent Ficoll400, a nonionic synthetic polymer of sucrose. Furthermore, we demonstrate how MMC modulates the distribution of key ECM molecules within the reconstituted matrix scaffolds. As a proof of concept, we compared different variants of kidney-derived fibrillated matrices in cell culture experiments referring to specific requirements of kidney tissue engineering approaches. The results revealed that MMC-tailored matrices support the morphogenesis of human umbilical vein endothelial cells (HUVECs) into capillary networks and of murine kidney stem cells (KSCs) into highly branched aggregates. The established methodology is concluded to provide generally applicable new options for tailoring tissue-specific multiphasic matrices in vitro. Tissue-derived fibrillated matrices can be instrumental for the in vitro reconstitution of multiphasic extracellular microenvironments. However, despite of several advantages, the obtained scaffolds so far offer a rather narrow range of materials

  12. [Atrial fibrillation and regular tachycardia in two young patients--are both treated with atrial fibrillation ablation?].

    Science.gov (United States)

    von Bodman, G; Brömsen, J; Kopf, C; Füller, M; Block, M

    2014-04-17

    Two young patients with documented episodes of symptomatic paroxysmal atrial fibrillation have been referred for pulmonary vein isolation. Both patients had a history of concomitant regular tachycardia. in both cases pulmonaryvein isolation has not been performed but in each patient a supraventricular tachycardia (right focal atrial tachycardia/atrioventricular reentry tachycardia) could be induced and ablated instead. Concomitant supraventricular tachycardia acting as a trigger arrhythmia is frequent in young patients with atrial fibrillation without underlying cardiacdisease. In these patients a concomitant supra-ventricular tachycardia should beexcluded by electrophysiological study or ablated before pulmonary vein isolation or initiating an antiarrhythmic drug therapy. In most cases ablation of supraventricular tachycardia is safe and successful whereas the risks of ablative therapy of atrial fibrillation can not be neglected and success is moderate.

  13. Fibril morphology and tendon mechanical properties in patellar tendinopathy: effects of heavy slow resistance training.

    Science.gov (United States)

    Kongsgaard, Mads; Qvortrup, Klaus; Larsen, Jytte; Aagaard, Per; Doessing, Simon; Hansen, Philip; Kjaer, Michael; Magnusson, S Peter

    2010-04-01

    Patellar tendinopathy is characterized by pathologic abnormalities. Heavy slow resistance training (HSR) is effective in the management of patellar tendinopathy, but the underlying functional mechanisms remain elusive. To investigate fibril morphology and mechanical properties in patellar tendinopathy and the effect of HSR on these properties. Cohort study; Level of evidence, 2. Eight male patients with patellar tendinopathy completed 12 weeks of HSR. Nine healthy subjects served as controls. Assessments were conducted at baseline and at 12 weeks. Patients assessed symptoms/function and maximal tendon pain during activity. Tendon biopsy samples were analyzed for fibril density, volume fraction, and mean fibril area. Tendon mechanical properties were assessed using force and ultrasonography samplings. Patients improved in symptoms/function (P = .02) and maximal tendon pain during activity (P = .008). Stiffness and modulus of control and tendinopathy tendons were similar at baseline. Stiffness remained unaffected in control tendons (3487 +/- 392 to 3157 +/- 327 N/mm, P = .57) but declined in tendinopathic tendons at 12 weeks (3185 +/- 187 to 2701 +/- 201 N/mm, P = .04). At baseline, fibril volume fraction was equal, fibril density smaller (P = .03), and mean fibril area tended to be higher in tendinopathy versus controls (P = .07). Fibril morphology remained unchanged in controls but fibril density increased (70% +/- 18%, P = .02) and fibril mean area decreased (-26% +/- 21%, P = .04) in tendinopathic tendons after HSR. Fibril morphology is abnormal in tendinopathy, but tendon mechanical properties are not. Clinical improvements after HSR were associated with changes in fibril morphology toward normal fibril density and mean fibril area. Heavy slow resistance training improved the clinical outcome of patellar tendinopathy, and these improvements were associated with normalization of fibril morphology, most likely due to a production of new fibrils.

  14. Using mechanical produced TI-moduls with a favourable facade construction for prefabricated building with light concrete slabs. Final report; Einsatz maschinell gefertigter TWD-Module in einer optimierten Fassadenkonstruktion an Montagebauten mit Leichtbetonelementen. Abschlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    Russ, C. [Fraunhofer-Institut fuer Solare Energiesysteme (ISE), Freiburg im Breisgau (Germany); Klinkert, V. [Hochschule fuer Technik, Wirtschaft und Kultur Leipzig (F.H.) (Germany)

    2000-07-01

    The existing building stock is characterized by high energy related carbon emissions due to high demands of fossil fuels. The present project investigates how well various solar systems succeeded at reducing the high energy consumption in a retrofitted school building in Wurzen, Germany. The renovated school building is highly representative for Eastern Germany, as it is mainly constructed out of prefabricated building elements. 300 m{sup 2} of transparently insulation were integrated into the Southern facade at comparably moderate system costs since the external shading device for the TI-wall and the windows were integrated into a single unit. Other features of the renovation were improved opaque insulation, new double-glazed windows with a low emissive coat and a new heating system. The new controlling system of the central heating is running on a central computer and is based on indoor room temperatures and the time table of the school. Buildings which are constructed out of prefabricated, light concrete building elements - like the one investigated in this project - require specially construction to attach the TI-moduls to the external building wall. For the investigated building, an energy yield of the TI-facade of 76 kWh/m{sup 2} facade area has been achieved. A solar-thermal system efficiency of 18% was observed and the specific heating demand was reduced from 170 kWh/m{sup 2} to 53 kWh/m{sup 2} after renovation which corresponds to a reduction of 69%. The system costs of the TI-wall consisted of 62% from TI-moduls, 14% for the shading device, 14% for the supporting structure and 10% for the installation. The equivalent energy costs archived in this project, related of the whole renovation, were 0.45 DM/kWh without subsides, and 0.24 DM/kWh with subsides. These results demonstrate, that the energy yields of a transparently insulated solar mass wall can balance out heat transmission and ventilation losses in middle European climate. (orig.) [German] In der

  15. Using mechanical produced TI-moduls with a favourable facade construction for prefabricated building with light concrete slabs. Final report; Einsatz maschinell gefertigter TWD-Module in einer optimierten Fassadenkonstruktion an Montagebauten mit Leichtbetonelementen. Abschlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    Russ, C. [Fraunhofer-Institut fuer Solare Energiesysteme (ISE), Freiburg im Breisgau (Germany); Klinkert, V. [Hochschule fuer Technik, Wirtschaft und Kultur Leipzig (F.H.) (Germany)

    2000-07-01

    The existing building stock is characterized by high energy related carbon emissions due to high demands of fossil fuels. The present project investigates how well various solar systems succeeded at reducing the high energy consumption in a retrofitted school building in Wurzen, Germany. The renovated school building is highly representative for Eastern Germany, as it is mainly constructed out of prefabricated building elements. 300 m{sup 2} of transparently insulation were integrated into the Southern facade at comparably moderate system costs since the external shading device for the TI-wall and the windows were integrated into a single unit. Other features of the renovation were improved opaque insulation, new double-glazed windows with a low emissive coat and a new heating system. The new controlling system of the central heating is running on a central computer and is based on indoor room temperatures and the time table of the school. Buildings which are constructed out of prefabricated, light concrete building elements - like the one investigated in this project - require specially construction to attach the TI-moduls to the external building wall. For the investigated building, an energy yield of the TI-facade of 76 kWh/m{sup 2} facade area has been achieved. A solar-thermal system efficiency of 18% was observed and the specific heating demand was reduced from 170 kWh/m{sup 2} to 53 kWh/m{sup 2} after renovation which corresponds to a reduction of 69%. The system costs of the TI-wall consisted of 62% from TI-moduls, 14% for the shading device, 14% for the supporting structure and 10% for the installation. The equivalent energy costs archived in this project, related of the whole renovation, were 0.45 DM/kWh without subsides, and 0.24 DM/kWh with subsides. These results demonstrate, that the energy yields of a transparently insulated solar mass wall can balance out heat transmission and ventilation losses in middle European climate. (orig.) [German] In der

  16. Development of a relational database for rated values of metallic materials. Final report; Entwicklung einer relationalen Datenbank fuer Sollwerte metallischer Werkstoffe; Schlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    Kowalski, P.; Hartung, T.; Kirchheiner, R.

    1993-03-01

    The ``Rated Value Material Database (SWDB)`` was prepared within the RandD project ``Corrosion Information System (CORIS)`` to manage the contents of standards, specifications and general information referring to metallic materials which are of relevance for an engineer`s practical work. The main function of this material database is to make information on the materials whose systems are included in CORIS available. Furthermore, the SWDB can also be used separately to find information on chemical compositions, mechanical-technological data, physical properties as well as general information on application and processing. A mass data transformer, which was developed in addition, integrates the rated data of a neutral material control board (RW-TUeV, Essen) and therefore guarantees the error-free application of SWDB on the basis of verified data. A relational database system comprising the corresponding programming tools as well as a graphical user interface, was used for reasons for compatibility and in order to simplify the conversational programming. All development stages - i.e. from the first design to the implementation - materialized in close cooperation with the partners within the project and the instructed subcontractor and institutions. (orig.) [Deutsch] Im Rahmen des FundE-Projektes Korrosionsinformationssystem CORIS wurde die Sollwert-Werkstoff-Datenbank (SWDB) entwickelt zur Verwaltung der in der Ingenieurpraxis relevanten Inhalte von Normen, Spezifikationen und allgemeinen Informationen ueber metallische Werkstoffe. Die Hauptfunktion dieser Werkstoff-Datenbank besteht in der Bereitstellung von Werkstoffinformationen zu den in CORIS erfassten Werkstoffsystemen. Darueber hinaus kann die SWDB auch isoliert eingesetzt werden zum Recherchieren der chemischen Zusammensetzungen, mechanisch-technologischer Werte, physikalischer Eigenschaften und allgemeiner Anwendungs- und Verarbeitungsinformationen. Ein zusaetzlich entwickelter Massendaten

  17. Physicochemical characteristics and fibril-forming properties of collagen from paddlefish (Polyodon spathula and globefish (Fugu flavidus skin byproducts

    Directory of Open Access Journals (Sweden)

    Shanshan WANG

    Full Text Available Abstract Acid-soluble collagen (ASC and pepsin-soluble collagen (PSC from the skin byproducts of paddlefish (ASC-P and PSC-P and globefish (ASC-G and PSC-G were purified and characterized. The imino acid contents of ASC-P, PSC-P, ASC-G and PSC-G were 194.1, 197.9, 186.4 and 189.7 residues/1000 residues, respectively. SDS-polyacrylamide gel electrophoresis (SDS-PAGE and Fourier transform infrared spectroscopy (FTIR confirmed that all four samples composed of two different α1- and α2-chains with integrated triple-helical structure. Denaturation temperatures of ASC-P, PSC-P, ASC-G and PSC-G were 29.6, 28.2, 27.4 and 26.9 °C, respectively. Based on Transmission electron microscopy (TEM observation, all four samples could assemble into fibrils in vitro with D-periodicity. However, the fibril-forming rate of ASC-P and PSC-P was more rapid than that of ASC-G and PSC-G. Scanning electron microscopy (SEM analysis confirmed well-defined fibril morphologies,the diameter of fibrils from ASC-P and PSC-P was thicker than those of ASC-G and PSC-G after 24 h incubation. These results indicated that paddlefish and globefish skin collagens could be alternatives to terrestrial collagens for applications in food-packaging, nutraceutical and pharmaceutical industries.

  18. Does in-hospital ventricular fibrillation affect prognosis after myocardial infarction?

    DEFF Research Database (Denmark)

    Jensen, G V; Torp-Pedersen, C; Hildebrandt, P

    1997-01-01

    -eight (12.4%) of the patients had ventricular fibrillation in hospital. The following risk factors were included in multivariate models to estimate their importance for 30-day and long-term (median 7 year) prognosis: age, gender, ventricular fibrillation, congestive heart failure, pulmonary oedema...... fibrillation secondary to heart failure compared to patients without ventricular fibrillation. For patients surviving more than 30 days, relative risk of death in those with ventricular fibrillation was 1.11 (95% confidence interval 0.93-1.34, P = 0.26). Logistic regression analysis of relative risk associated...

  19. Catheter ablation of a monofocal premature ventricular complex triggering idiopathic ventricular fibrillation.

    Science.gov (United States)

    Takatsuki, S; Mitamura, H; Ogawa, S

    2001-07-01

    A 62 year old man was admitted for evaluation of recurrent episodes of syncope. A surface ECG showed frequent repetitive premature ventricular complexes of right ventricular outflow tract origin. Ventricular fibrillation was inducible by programmed electrical stimulation but otherwise cardiac evaluation was unremarkable. A diagnosis of idiopathic ventricular fibrillation was made and an implantable cardioverter-defibrillator (ICD) was installed. However, spontaneous ventricular fibrillation recurred, requiring repeated ICD discharges. The ventricular fibrillation was reproducibly triggered by a single premature ventricular complex with a specific QRS morphology. Radiofrequency catheter ablation was carried out to eradicate this complex. No ventricular fibrillation has developed after this procedure, and the patient does not require drug treatment.

  20. Glucagon stop-go kinetics supports a monomer-trimer fibrillation model

    CERN Document Server

    Kosmrlj, Andrej; Kyrsting, Anders; Otzen, Daniel E; Oddershede, Lene B; Jensen, Mogens H

    2014-01-01

    We investigate in vitro fibrillation kinetics of the hormone peptide glucagon at various concentrations using confocal microscopy and determine the glucagon fibril persistence length $60 \\mu\\textrm{m}$. At all concentrations we observe that periods of individual fibril growth are interrupted by periods of stasis. The growth probability is large at high and low concentrations and is reduced for intermediate glucagon concentrations. To explain this behavior we propose a simple model, where fibrils come in two forms, one built entirely from glucagon monomers and one entirely from glucagon trimers. The opposite building blocks act as fibril growth blockers, and this generic model reproduces experimental behavior well.

  1. Asymmetrical dimethylarginine level in atrial fibrillation.

    Science.gov (United States)

    Cengel, Atiye; Sahinarslan, Asife; Biberoğlu, Gursel; Hasanoğlu, Alev; Tavil, Yusuf; Tulmaç, Murat; Ozdemir, Murat

    2008-02-01

    Atrial fibrillation (AF) is known to be related with increased risk of thromboembolic events. Asymmetrical dimethylarginine (ADMA), which is an endogenous inhibitor of nitric oxide synthase (NOS), can cause endothelial dysfunction by decreasing nitric oxide (NO) and lead to increased risk of thrombosis. In the present study our aim was to compare plasma levels of ADMA in patients with acute onset ( 1 year) to determine the risk of thrombosis. 17 patients with the first detected attack of AF within the first 24 hours of presentation (group 1), 25 patients who had permanent chronic AF lasting at least 1 year or more (group II) and 18 healthy persons as the control group (group III) were included in the study. For each patient the plasma ADMA, L-arginine, symmetrical dimethylarginine (SDMA) concentrations were measured by high-performance liquid chromatography in venous blood samples collected before cardioversion. We compared the plasma ADMA, L-arginine and SDMA concentrations between the groups. Plasma L-arginine (78.18 +/- 28.29 vs. 73.14 +/- 14.11 vs. 71.03 +/- 21.31, P = 0.549) and plasma SDMA concentrations (0.38 +/-0.18 vs. 0.42 +/- 0.21 vs. 0.32 +/- 0.24, P = 0.224) were similar in all groups. There was a significant difference between plasma ADMA concentrations (0.76 +/- 0.27 vs. 0.50 +/- 0.26 vs. 0.36 +/- 0.20, P < 0.001) among the groups. When we compared plasma ADMA levels between the subgroups, we also found a significant difference (P = 0.002 when comparing group I and group II, P < 0.001 when comparing of group I and group III, P = 0.042 when compareng of group II and group III). ADMA levels in patients with acute onset AF were significantly increased when compared with patients with chronic AF and the healthy control group indicating the presence of endothelial dysfunction and a prothrombotic state even in a very early phase of AF.

  2. Konstruktion, Aufbau und Erprobung einer Einzelionen-Bestrahlungsapparatur und Untersuchung der Inaktivierung von Sporen von bacillus subtilis durch einzelne sehr schwere Ionen (Z $>$ 27) in Abhängigkeit vom Stossparameter

    CERN Document Server

    Weisbrod, U

    1988-01-01

    Konstruktion, Aufbau und Erprobung einer Einzelionen-Bestrahlungsapparatur und Untersuchung der Inaktivierung von Sporen von bacillus subtilis durch einzelne sehr schwere Ionen (Z $>$ 27) in Abhängigkeit vom Stossparameter

  3. Investigations of co-combustion of plastics in a coal dust furnace; Untersuchungen zur Mitverbrennung von Kunststoffen in einer Kohlestaubfeuerung

    Energy Technology Data Exchange (ETDEWEB)

    Gerhardt, T.; Spliethoff, H.; Hein, K.R.G. [Stuttgart Univ. (Germany). Inst. fuer Verfahrenstechnik und Dampfkesselwesen (IVD); Christill, M.; Kicherer, A.; Seifert, H. [BASF AG, Verfahrenstechnik-ZET/EH-L544, Ludwigshafen am Rhein (Germany)

    1996-12-31

    In a cooperation project of the Institute of Process Engineering and Power Plant TEchnology (IVD) at the University of Stuttgart and the BASF AG, investigations of co-combustion of plastic material in a coal dust furnace were carried out. The central question of the research work was the ignition and burnout of the particles in dependence of the residence time in the hot part of the furnace. Particle sizes were varied with the aim to define the largest possible particle size in order to minimize the cost of fuel preparation by grinding. On the other hand, tests were made with pure materials and synthetic mixtures of these in order to characterize the influence of different types of plastic. The investigations showed that plastics are suited as fuels for coal dust furnaces, and that the cost of fuel preparation can be reduced to an acceptable level. With polyethylene, which is difficult to ignite, an upper particle size limit of 1.25 to 1.5 mm was reached in the IVD test stand. In industrial applications with a different burner arrangement, even better results may be expected. (orig/AKB) [Deutsch] In einer Zusammenarbeit zwischen dem Institut fuer Verfahrenstechnik und Dampfkesselwesen (IVD) der Universitaet Stuttgart und der BASF AG wurden Versuche zur Coverbrennung von Kunststoffen in einer Kohlenstaubfeuerung durchgefuehrt. Im Mittelpunkt der Untersuchungen standen Zuendung und Abbrand der Kunststoffpartikel in Abhaengigkeit von der Verweilzeit im heissen Bereich der Brennkanner. Variiert wurden hierzu zum einen die Partikelgroessen mit dem Ziel, den Aufbereitungsaufwand durch Zerkleinerung zu minimieren. Zur Charakterisierung der Einfluesse verschiedener Kunststoffarten wurden die Versuche mit unterschiedlichen Reinkunststoffen und synthetischen Mischungen durchgefuehrt. Die Versuche zeigen, dass sich Kunststoffe mit vertretbarem Mahlaufwand in der Staubfeuerung einsetzen lassen. Am Beispiel des Polyethylen, eines der thermogravimetrischen Analyse nach relativ

  4. Molecular structures of quiescently grown and brain-derived polymorphic fibrils of the Alzheimer amyloid abeta9-40 peptide: a comparison to agitated fibrils.

    Directory of Open Access Journals (Sweden)

    Chun Wu

    2010-03-01

    Full Text Available The presence of amyloid deposits consisting primarily of Amyloid-beta (Abeta fibril in the brain is a hallmark of Alzheimer's disease (AD. The morphologies of these fibrils are exquisitely sensitive to environmental conditions. Using molecular dynamics simulations combined with data from previously published solid-state NMR experiments, we propose the first atomically detailed structures of two asymmetric polymorphs of the Abeta(9-40 peptide fibril. The first corresponds to synthetic fibrils grown under quiescent conditions and the second to fibrils derived from AD patients' brain-extracts. Our core structure in both fibril structures consists of a layered structure in which three cross-beta subunits are arranged in six tightly stacked beta-sheet layers with an antiparallel hydrophobic-hydrophobic and an antiparallel polar-polar interface. The synthetic and brain-derived structures differ primarily in the side-chain orientation of one beta-strand. The presence of a large and continually exposed hydrophobic surface (buried in the symmetric agitated Abeta fibrils may account for the higher toxicity of the asymmetric fibrils. Our model explains the effects of external perturbations on the fibril lateral architecture as well as the fibrillogenesis inhibiting action of amphiphilic molecules.

  5. Engineering scale development of the vapor-liquid-solid (VLS) process for the production of silicon carbide fibrils and linear fibril assemblies

    Energy Technology Data Exchange (ETDEWEB)

    Tenhover, M.; Biernacki, J. [Carborundum Co., Niagara Falls, NY (United States); Schatz, K.; Ko, F. [Advanced Product Development, Inc., Bristol, PA (United States)

    1995-08-01

    In order to exploit the superior thermomechanical properties of the VLS fibril, the feasibility of scaled-up production of the SiC fibril is demonstrated in this study. Through time series study and computer simulation, the parameters affecting the growth process and properties of the fibrils were examined. To facilitate translation of the superior mechanical properties into higher level preform structures, conventional and unconventional processing methods were evaluated. As revealed by scanning electron microscopic examination and X-ray diffractometry, high level alignment of the fibrils was achieved by the wet-laid process.

  6. Distinguishing the cross-beta spine arrangements in amyloid fibrils using FRET analysis.

    Science.gov (United States)

    Deng, Wei; Cao, Aoneng; Lai, Luhua

    2008-06-01

    The recently published microcrystal structures of amyloid fibrils from small peptides greatly enhanced our understanding of the atomic-level structure of the amyloid fibril. However, only a few amyloid fibrils can form microcrystals. The dansyl-tryptophan fluorescence resonance energy transfer (FRET) pair was shown to be able to detect the inter-peptide arrangement of the Transthyretin (105-115) amyloid fibril. In this study, we combined the known microcrystal structures with the corresponding FRET efficiencies to build a model for amyloid fibril structure classification. We found that fibrils with an antiparallel structural arrangement gave the largest FRET signal, those with a parallel arrangement gave the lowest FRET signal, and those with a mixed arrangement gave a moderate FRET signal. This confirms that the amyloid fibril structure patterns can be classified based on the FRET efficiency.

  7. Glucagon Amyloid-like Fibril Morphology Is Selected via Morphology-Dependent Growth Inhibition

    DEFF Research Database (Denmark)

    Andersen, C.B.; Otzen, D.; Christiansen, Gunna

    2007-01-01

    concentrations, we find that the lag time has an unexpected maximum at a concentration of 1 mg/mL, with faster fibrillation at both lower and higher concentrations. Seeding experiments show that small amounts of straight fibril seeds can accelerate fibril growth at both low and high glucagon concentration, while...... twisted fibril seeds cannot grow at high concentrations. We conclude that there exists a morphology-dependent mechanism for inhibition of glucagon fibril growth. Light scattering experiments indicate that glucagon is mainly monomeric below 1 mg/mL and increasingly trimeric above this concentration. We...... propose that the glucagon trimer is able to specifically inhibit growth of the twisted fibril morphology. Such inhibitory binding of molecules in an unproductive conformation could also play a role in the selection of morphologies for other fibril-forming peptides and proteins....

  8. Molecular adaptations in human atrial fibrillation : mechanisms of protein remodeling

    NARCIS (Netherlands)

    Brundel, Bianca Johanna Josephina Maria

    2000-01-01

    The main goal was to study the molecular remodeling in human atrial fibrillation. We focussed on gene expression of proteins wich influence the calcium homeostasis and action potential duration in human AF. The impact of modulation sysems like the natriuretic peptide system and the endothelin system

  9. Occlusion of left atrial appendage in patients with atrial fibrillation

    Directory of Open Access Journals (Sweden)

    О. Н. Ганеева

    2015-10-01

    Full Text Available The article reviews a new method of prophylaxis of thromboembolitic complications, specifically occlusion of left atrial appendage, in patients with atrial fibrillation. Indications and contraindications for the procedure, as well as a step-by-step process of the intervention itself are described. Special emphasis is placed on the up-to-date evidence and the review of clinical trials.

  10. Ventricular rate control of atrial fibrillation in heart failure

    NARCIS (Netherlands)

    Rienstra, Michiel; Van Gelder, Isabelle C

    2013-01-01

    In the last few years, there has been a major shift in the treatment of atrial fibrillation (AF) in the setting of hear failure (HF), from rhythm to ventricular rate control in most patients with both conditions. In this article, the authors focus on ventricular rate control and discuss the indicati

  11. Plasma YKL-40, a new biomarker for atrial fibrillation?

    DEFF Research Database (Denmark)

    Henningsen, Kristoffer Mads; Therkelsen, Susette Krohn; Johansen, Julia Sidenius;

    2009-01-01

    AIMS: The aim of this study was to determine changes in a new potential biomarker plasma YKL-40 in patients with atrial fibrillation (AF) before and after electrical cardioversion (CV). METHODS AND RESULTS: Plasma concentrations of YKL-40 were measured in 56 patients (mean age 65 years, range 34-...

  12. Fibril Formation from Pea Protein and Sesequent Gel Formation

    NARCIS (Netherlands)

    Munialo, C.D.; Martin, A.H.; Linden, van der E.; Jongh, de H.H.J.

    2014-01-01

    The objective of this study was to characterize fibrillar aggregates made using pea proteins, to assemble formed fibrils into protein-based gels, and to study the rheological behavior of these gels. Micrometer-long fibrillar aggregates were observed after pea protein solutions had been heated for 20

  13. Pattern of atrial fibrillation and risk of outcomes

    DEFF Research Database (Denmark)

    Banerjee, Amitava; Taillandier, Sophie; Olesen, Jonas Bjerring;

    2012-01-01

    BACKGROUND: Risk of stroke and thromboembolism (TE) in patients with non-valvular atrial fibrillation (NVAF) is categorised in stroke risk stratification scores. The role of pattern of NVAF in risk prediction is unclear in contemporary 'real world' cohorts. METHODS AND RESULTS: Patients with NVAF...

  14. Hospitalisation patterns change over time in patients with atrial fibrillation

    DEFF Research Database (Denmark)

    Fristrup Qvist, Janne; Høgh Sørensen, Pernille; Dixen, Ulrik

    2014-01-01

    INTRODUCTION: Atrial fibrillation (AF) is a cardiac epidemic. In this study, we aimed to describe the causes of hospital-isation in an AF population over time and to study how different AF treatment strategies affected hospitalization. MATERIAL AND METHODS: This was an observational study in which...

  15. Use of Oral Anticoagulation Therapy in Atrial Fibrillation after Stroke

    DEFF Research Database (Denmark)

    Jespersen, Stine Funder; Christensen, Louisa M; Christensen, Anders;

    2013-01-01

    Background. The knowledge is still sparse about patient related factors, influencing oral anticoagulation therapy (OAC) rates, in stroke patients with atrial fibrillation (AF). Aims. To assess the use of OAC in ischemic stroke patients diagnosed with AF and to identify patient related factors...

  16. Paroxysmal Atrial Fibrillation in a Mission-Assigned Astronaut

    Science.gov (United States)

    Bauer, Peter A.; Polk, J. D.

    2010-01-01

    This presentation will explore the clinical and administrative conundrums faced by the flight surgeon upon discovering asymptomatic paroxysmal atrial fibrillation seven months prior to scheduled long duration spaceflight. The presenter will discuss the decision-making process as well as the clinical and operational outcomes.

  17. KCNE3 R53H substitution in familial atrial fibrillation

    Institute of Scientific and Technical Information of China (English)

    ZHANG Dai-fu; LIANG Bo; LIN Jie; LIU Ban; ZHOU Qin-shu; YANG Yi-qing

    2005-01-01

    @@ Atrial fibrillation (AF) is the most common cardiac arrhythmia with debilitating compli-cations of stroke. Multiple-wavelet re-entry and focal activation from pulmonary vein foci are two dominant electrophysiological theories of AF. Atrial electrical remodeling plays a role in the maintenance of AF. However, molecular mechanisms of the arrhythmia are still poorly understood.

  18. Risk factors for atrial fibrillation incidence and progression

    NARCIS (Netherlands)

    Vermond, Robert Aldo

    2016-01-01

    During atrial fibrillation (AF) irregular activation of the hearts atria occur, causing an irregular heart rate and altered blood flow. AF is the most common heart rhythm disorder, causing stroke, heart failure, dementia, reduced quality of life and high health care expences. AF is diagnosed increas

  19. Insulin resistance and atrial fibrillation (from the Framingham Heart Study)

    NARCIS (Netherlands)

    Fontes, João D; Lyass, Asya; Massaro, Joseph M; Rienstra, Michiel; Dallmeier, Dhayana; Schnabel, Renate B; Wang, Thomas J; Vasan, Ramachandran S; Lubitz, Steven A; Magnani, Jared W; Levy, Daniel; Ellinor, Patrick T; Fox, Caroline S; Benjamin, Emelia J

    2012-01-01

    Diabetes mellitus and obesity are increasing in prevalence and are associated with an elevated risk of atrial fibrillation (AF). Given the aging of the United States population, AF is projected to concomitantly increase in prevalence in the upcoming decades. Both diabetes and obesity are associated

  20. Fibril Formation from Pea Protein and Subsequent Gel Formation

    NARCIS (Netherlands)

    Munialo, XC.D.; Martin, A.H.; Linden, E. van der; Jongh, H.H.J de

    2014-01-01

    The objective of this study was to characterize fibrillar aggregates made using pea proteins, to assemble formed fibrils into protein-based gels, and to study the rheological behavior of these gels. Micrometer-long fibrillar aggregates were observed after pea protein solutions had been heated for 20

  1. Management of atrial fibrillation in patients with heart failure

    NARCIS (Netherlands)

    Neuberger, Hans-Ruprecht; Mewis, Christian; van Veldhuisen, Dirk J.; Schotten, Ulrich; van Gelder, Isabelle C.; Allessie, Maurits A.; Boehm, Michael

    2007-01-01

    Atrial. fibrillation (AF) and chronic heart failure (CHF) are two major and even growing cardiovascular conditions that often coexist. However, few data are available to guide treatment of AF in patients with CHF. This review summarizes current literature concerning the following topics: (i)

  2. New oral anticoagulants for patients with nonvalvular atrial fibrillation.

    Science.gov (United States)

    Holden, Amber; Azimi, Nassir; Forest, Christopher P

    2015-11-01

    Four new oral anticoagulants have been approved for reducing stroke risk in patients with nonvalvular atrial fibrillation. Compared with warfarin, these agents offer a more predictable dose response with fewer food and drug interactions and no regular blood monitoring, although some of the drugs have an increased risk of major gastrointestinal bleeding. This article reviews the new drugs.

  3. Edoxaban versus warfarin in patients with atrial fibrillation

    DEFF Research Database (Denmark)

    Giugliano, Robert P; Ruff, Christian T; Braunwald, Eugene

    2013-01-01

    BACKGROUND: Edoxaban is a direct oral factor Xa inhibitor with proven antithrombotic effects. The long-term efficacy and safety of edoxaban as compared with warfarin in patients with atrial fibrillation is not known. METHODS: We conducted a randomized, double-blind, double-dummy trial comparing t...

  4. Edoxaban versus warfarin in patients with atrial fibrillation

    NARCIS (Netherlands)

    Giugliano, R.P.; Ruff, C.T.; Braunwald, E.; Murphy, S.A.; Wiviott, S.D.; Halperin, J.L.; Waldo, A.L.; Ezekowitz, M.D.; Weitz, J.I.; Spinar, J.; Ruzyllo, W.; Ruda, M.; Koretsune, Y.; Betcher, J.; Shi, M.; Grip, L.T.; Patel, S.P.; Patel, I.; Hanyok, J.J.; Mercuri, M.; Antman, E.M.; Verheugt, F.W.A.

    2013-01-01

    BACKGROUND: Edoxaban is a direct oral factor Xa inhibitor with proven antithrombotic effects. The long-term efficacy and safety of edoxaban as compared with warfarin in patients with atrial fibrillation is not known. METHODS: We conducted a randomized, double-blind, double-dummy trial comparing two

  5. Anticoagulant treatment in patients with atrial fibrillation and ischemic stroke

    DEFF Research Database (Denmark)

    Brunner-Frandsen, Nicole; Dammann Andersen, Andreas; Ashournia, Hamoun;

    2015-01-01

    BACKGROUND: Atrial fibrillation (AF) is the most common cardiac dysrhythmia, with a lifetime risk of 25%, and it is a well-known independent risk factor for ischemic stroke. Over the last 15 years, efforts have been made to initiate relevant treatment in patients with AF. A retrospective study wa...

  6. Clinical considerations of anticoagulation therapy for patients with atrial fibrillation

    Institute of Scientific and Technical Information of China (English)

    Shu ZHANG

    2012-01-01

    Atrial fibrillation (AF) increases the risk of stroke.New anticoagulation agents have recently provided alternative and promising approaches.This paper reviews the current state of anticoagulation therapy in AF patients,focusing on various clinical scenarios and on comparisons,where possible,between western and eastern populations.

  7. Outcomes in a Warfarin-Treated Population With Atrial Fibrillation

    DEFF Research Database (Denmark)

    Björck, Fredrik; Renlund, Henrik; Lip, Gregory Y H;

    2016-01-01

    IMPORTANCE: Vitamin K antagonist (eg, warfarin) use is nowadays challenged by the non-vitamin K antagonist oral anticoagulants (NOACs) for stroke prevention in atrial fibrillation (AF). NOAC studies were based on comparisons with warfarin arms with times in therapeutic range (TTRs) of 55.2% to 64...

  8. Molecular mechanisms of remodeling in human atrial fibrillation

    NARCIS (Netherlands)

    Brundel, BJJM; Henning, RH; Kampinga, HH; Van Gelder, IC; Crijns, HJGM

    2002-01-01

    An important acknowledgement of the last several years is that atrial fibrillation (AF) modifies the electrical properties of the atrium in a way that promotes its occurrence and maintenance. This arrhythmogenic electrophysiological remodeling is well established, but can not explain by itself that

  9. Atrial fibrillation: An analysis of etiology and management pattern in ...

    African Journals Online (AJOL)

    None of the patients had evidence of stroke risk evaluation in their notes and less than ... treatment despite all the patients having moderate to high risk of stroke from our ... Keywords: Atrial fibrillation, thrombosis, CHADS2 Score, stroke risk, ...

  10. Cardiovascular Risk Factors and Atrial Fibrillation: What is the Link?

    OpenAIRE

    Yaariv Khaykin

    2009-01-01

    Atrial fibrillation is a common cardiac arrhythmia. It is well known to occur in older patients with comorbid conditions such congestive heart failure and ischemic heart disease.1-3 In these otherwise sick individuals it is associated with higher long term morbidity and mortality.

  11. Outcomes associated with familial versus nonfamilial atrial fibrillation

    DEFF Research Database (Denmark)

    Gundlund, Anna; Olesen, Jonas Bjerring; Staerk, Laila

    2016-01-01

    BACKGROUND: We examined all-cause mortality and long-term thromboembolic risk (ischemic stroke, transient ischemic attack, systemic thromboembolism) in patients with and without familial atrial fibrillation (AF). METHODS AND RESULTS: Using Danish nationwide registry data, we identified all patients...

  12. Amyloid fibril systems reduce, stabilize and deliver bioavailable nanosized iron

    Science.gov (United States)

    Shen, Yi; Posavec, Lidija; Bolisetty, Sreenath; Hilty, Florentine M.; Nyström, Gustav; Kohlbrecher, Joachim; Hilbe, Monika; Rossi, Antonella; Baumgartner, Jeannine; Zimmermann, Michael B.; Mezzenga, Raffaele

    2017-07-01

    Iron-deficiency anaemia (IDA) is a major global public health problem. A sustainable and cost-effective strategy to reduce IDA is iron fortification of foods, but the most bioavailable fortificants cause adverse organoleptic changes in foods. Iron nanoparticles are a promising solution in food matrices, although their tendency to oxidize and rapidly aggregate in solution severely limits their use in fortification. Amyloid fibrils are protein aggregates initially known for their association with neurodegenerative disorders, but recently described in the context of biological functions in living organisms and emerging as unique biomaterial building blocks. Here, we show an original application for these protein fibrils as efficient carriers for iron fortification. We use biodegradable amyloid fibrils from β-lactoglobulin, an inexpensive milk protein with natural reducing effects, as anti-oxidizing nanocarriers and colloidal stabilizers for iron nanoparticles. The resulting hybrid material forms a stable protein-iron colloidal dispersion that undergoes rapid dissolution and releases iron ions during acidic and enzymatic in vitro digestion. Importantly, this hybrid shows high in vivo iron bioavailability, equivalent to ferrous sulfate in haemoglobin-repletion and stable-isotope studies in rats, but with reduced organoleptic changes in foods. Feeding the rats with these hybrid materials did not result in abnormal iron accumulation in any organs, or changes in whole blood glutathione concentrations, inferring their primary safety. Therefore, these iron-amyloid fibril hybrids emerge as novel, highly effective delivery systems for iron in both solid and liquid matrices.

  13. Managing atrial fibrillation in the elderly: critical appraisal of dronedarone

    Directory of Open Access Journals (Sweden)

    Trigo P

    2011-12-01

    Full Text Available Paula Trigo, Gregory W FischerDepartment of Anesthesiology, Mount Sinai School of Medicine, New York, NY, USAAbstract: Atrial fibrillation is the most commonly seen arrhythmia in the geriatric population and is associated with increased cardiovascular morbidity and mortality. Treatment of the elderly with atrial fibrillation remains challenging for physicians, because this unique subpopulation is characterized by multiple comorbidities requiring chronic use of numerous medications, which can potentially lead to severe drug interactions. Furthermore, age-related changes in the cardiovascular system as well as other physiological changes result in altered drug pharmacokinetics. Dronedarone is a new drug recently approved for the treatment of arrhythmias, such as atrial fibrillation and/or atrial flutter. Dronedarone is a benzofuran amiodarone analog which lacks the iodine moiety and contains a methane sulfonyl group that decreases its lipophilicity. These differences in chemical structure are responsible for making dronedarone less toxic than amiodarone which, in turn, results in fewer side effects. Adverse events for dronedarone include gastrointestinal side effects and rash. No dosage adjustments are required for patients with renal impairment. However, the use of dronedarone is contraindicated in the presence of severe hepatic dysfunction.Keywords: atrial fibrillation, elderly, antiarrhythmic agents, amiodarone, dronedarone

  14. Clinical experience with apixaban in atrial fibrillation: implications of AVERROES

    Directory of Open Access Journals (Sweden)

    De Caterina R

    2011-07-01

    Full Text Available Raffaele De CaterinaInstitute of Cardiology and Center of Excellence on Aging, G d’Annunzio University, Chieti, G Monasterio Foundation, Pisa, ItalyAbstract: Atrial fibrillation is an extremely common arrhythmia, which substantially increases the risk of stroke and thromboembolism. Prevention of stroke and thromboembolism is therefore an important part of the management of atrial fibrillation. Guidelines until now have recommended that patients with atrial fibrillation receive some form of antithrombotic therapy, ie, a vitamin K antagonist or aspirin, with a preference for anticoagulants in most cases. However, current treatments are suboptimal, and despite the recommendations, many patients do not receive adequate thromboprophylaxis, because they are considered, for various reasons, “unsuitable” to receive a vitamin K antagonist. In this patient population, apixaban, a new oral anticoagulant inhibiting activated coagulation factor X, administered in fixed doses and without anticoagulation monitoring, has undergone testing against aspirin in the recently published AVERROES trial. This paper addresses the strengths and limitations of this trial and the practical relevance of the new clinical information it provides.Keywords: atrial fibrillation, apixaban, thromboprophylaxis 

  15. Monitoring the complexity of ventricular response in atrial fibrillation

    Directory of Open Access Journals (Sweden)

    H. Käsmacher

    2000-01-01

    Full Text Available Atrial fibrillation does not present a uniform extent of variability of the ventricular response exemplifying periodicities and more complex fluctuations, due to varying number and shape of atrial wavelets and aberrant conduction in the AV-junction. It was sought to categorise different degrees of complexity introducing an uncomplicated monitoring method for that objective.

  16. Cardioversion for atrial fibrillation in current European practice

    DEFF Research Database (Denmark)

    Hernández-Madrid, Antonio; Svendsen, Jesper Hastrup; Lip, Gregory Y.H.

    2013-01-01

    This survey was conducted to provide an insight into the current clinical practice regarding the use of cardioversion for atrial fibrillation (AF) in Europe. Responses were received from 57 centres across Europe, 71.9% of which were university hospitals. For electrical cardioversion, general anae...

  17. Increased plasma aldosterone during atrial fibrillation declines following cardioversion

    DEFF Research Database (Denmark)

    Soeby-Land, C; Dixen, U; Therkelsen, S K;

    2011-01-01

    The renin-angiotensin-aldosterone system (RAAS) may be activated during atrial fibrillation (AF); our aim was to evaluate the level of aldosterone in patients with either permanent AF, persistent AF scheduled for cardioversion or patients in sinus rhythm (SR). We hypothesized that an increased...... level of aldosterone is found in patients with AF, decreasing in patients with restored SR....

  18. Binding of fullerenes to amyloid beta fibrils: size matters.

    Science.gov (United States)

    Huy, Pham Dinh Quoc; Li, Mai Suan

    2014-10-01

    Binding affinity of fullerenes C20, C36, C60, C70 and C84 for amyloid beta fibrils is studied by docking and all-atom molecular dynamics simulations with the Amber force field and water model TIP3P. Using the molecular mechanic-Poisson Boltzmann surface area method one can demonstrate that the binding free energy linearly decreases with the number of carbon atoms of fullerene, i.e. the larger is the fullerene size, the higher is the binding affinity. Overall, fullerenes bind to Aβ9-40 fibrils stronger than to Aβ17-42. The number of water molecules trapped in the interior of 12Aβ9-40 fibrils was found to be lower than inside pentamer 5Aβ17-42. C60 destroys Aβ17-42 fibril structure to a greater extent compared to other fullerenes. Our study revealed that the van der Waals interaction dominates over the electrostatic interaction and non-polar residues of amyloid beta peptides play the significant role in interaction with fullerenes providing novel insight into the development of drug candidates against Alzheimer's disease.

  19. Ventricular rate control of atrial fibrillation in heart failure

    NARCIS (Netherlands)

    Rienstra, Michiel; Van Gelder, Isabelle C

    2013-01-01

    In the last few years, there has been a major shift in the treatment of atrial fibrillation (AF) in the setting of hear failure (HF), from rhythm to ventricular rate control in most patients with both conditions. In this article, the authors focus on ventricular rate control and discuss the

  20. Novel oral anticoagulants for stroke prevention in atrial fibrillation

    DEFF Research Database (Denmark)

    Lip, Gregory Y H; Bongiorni, Maria Grazia; Dobreanu, Dan

    2013-01-01

    The purpose of this European Heart Rhythm Association (EHRA) survey was to assess clinical practice in relation to stroke prevention in atrial fibrillation (AF), particularly into the use of novel oral anticoagulants (NOACs) for stroke prevention, among members of the EHRA electrophysiology (EP) ...

  1. Complexation of amyloid fibrils with charged conjugated polymers.

    Science.gov (United States)

    Ghosh, Dhiman; Dutta, Paulami; Chakraborty, Chanchal; Singh, Pradeep K; Anoop, A; Jha, Narendra Nath; Jacob, Reeba S; Mondal, Mrityunjoy; Mankar, Shruti; Das, Subhadeep; Malik, Sudip; Maji, Samir K

    2014-04-01

    It has been suggested that conjugated charged polymers are amyloid imaging agents and promising therapeutic candidates for neurological disorders. However, very less is known about their efficacy in modulating the amyloid aggregation pathway. Here, we studied the modulation of Parkinson's disease associated α-synuclein (AS) amyloid assembly kinetics using conjugated polyfluorene polymers (PF, cationic; PFS, anionic). We also explored the complexation of these charged polymers with the various AS aggregated species including amyloid fibrils and oligomers using multidisciplinary biophysical techniques. Our data suggests that both polymers irrespective of their different charges in the side chains increase the fibrilization kinetics of AS and also remarkably change the morphology of the resultant amyloid fibrils. Both polymers were incorporated/aligned onto the AS amyloid fibrils as evident from electron microscopy (EM) and atomic force microscopy (AFM), and the resultant complexes were structurally distinct from their pristine form of both polymers and AS supported by FTIR study. Additionally, we observed that the mechanism of interactions between the polymers with different species of AS aggregates were markedly different.

  2. Novel oral anticoagulants to prevent stroke in atrial fibrillation.

    NARCIS (Netherlands)

    Verheugt, F.W.A.

    2010-01-01

    Warfarin reduces the risk of stroke in atrial fibrillation by around 60%, while antiplatelet therapy is much less effective. Bleeding is, however, a notable adverse effect with warfarin. Another major drawback of warfarin is the need for frequent clotting assessment. Oral agents have been developed

  3. The new oral anticoagulants in atrial fibrillation: an update

    NARCIS (Netherlands)

    Verheugt, F.W.A.

    2013-01-01

    In patients with nonvalvular atrial fibrillation, oral anticoagulation with the vitamin K antagonists acenocoumarol, phenprocoumon and warfarin reduces the risk of stroke by more than 60 %, whereas single or double antiplatelet therapy is much less effective and sometimes associated with a similar b

  4. Comparative study of atrial fibrillation and AV conduction in mammals

    NARCIS (Netherlands)

    Meijler, F.L.; Tweel, I. van der

    1987-01-01

    Atrial fibrillation is one ofthe most common cardiac arrhythmias in humans. It a1so occurs quite frequent1y in dogs and horses. Comparative study of this arrhythmia may contribute to better understanding of the pathophysiologica1 mechanisms involved. In this study, we present a quantitative analysis

  5. Encapsulation systems based on ovalbumin fibrils and high methoxyl pectin

    NARCIS (Netherlands)

    Humblet-Hua, K.N.P.; Scheltens, G.; Linden, van der E.; Sagis, L.M.C.

    2011-01-01

    In this study we produced microcapsules using layer-by-layer adsorption of food-grade polyelectrolytes. The shell was built with alternating layers of ovalbumin fibrils and high methoxyl pectin. By varying the number of layers, the release of active ingredients can be controlled - increasing the num

  6. Left atrial appendage occlusion for stroke prevention in atrial fibrillation

    DEFF Research Database (Denmark)

    Tzikas, Apostolos; Shakir, Samera; Gafoor, Sameer;

    2015-01-01

    Aims: To investigate the safety, feasibility, and efficacy of left atrial appendage occlusion (LAAO) with the AMPLATZER Cardiac Plug (ACP) for stroke prevention in patients with atrial fibrillation (AF). Methods and results: Data from consecutive patients treated in 22 centres were collected...

  7. Epidemiology and genetics of ventricular fibrillation during acute myocardial infarction

    DEFF Research Database (Denmark)

    Glinge, Charlotte; Sattler, Stefan; Jabbari, Reza

    2016-01-01

    several genetic variants, both common and rare variants, have been associated to either VF or SCD. For this review, we searched PubMed for potentially relevant articles, using the following MeSH-terms: "sudden cardiac death", "ventricular fibrillation", "out-of-hospital cardiac arrest", "myocardial...

  8. Pharmacological therapy following catheter ablation of atrial fibrillation.

    Science.gov (United States)

    Rordorf, Roberto; Savastano, Simone; Gandolfi, Edoardo; Vicentini, Alessandro; Petracci, Barbara; Landolina, Maurizio

    2012-01-01

    Catheter ablation has been proven to be an effective treatment for patients with drug-resistant atrial fibrillation. Nevertheless its efficacy is limited to 60-80% of patients in different studies. Whether the use of pharmacological therapy after catheter ablation of atrial fibrillation might increase the procedural success rate is still a matter of debate. There is general agreement that antiarrhythmic drugs (AADs) are useful in the management of arrhythmias occurring in the very early period after catheter ablation (blanking period). On the contrary, limited data are available on the efficacy of AADs over a longer period. Some patients remain free of arrhythmia recurrences by the use of AADs that were ineffective before catheter ablation: whether this latter situation is to be considered a partial success of catheter ablation or a treatment failure, thus demanding a redo procedure, is still an open question. Some studies have also investigated the role of non-AADs [angiotensin-converting enzyme (ACE) inhibitors, angiotensin II receptor blockers, statins and corticosteroids] in preventing atrial fibrillation recurrences after catheter ablation, reporting conflicting results. Whereas there is a general consensus on the use of anticoagulation therapy in the first phase after catheter ablation, no definite data are available on the proper long-term management of anticoagulation therapy after catheter ablation. This review focuses on the still open issue of what is the optimal pharmacological treatment of patients after catheter ablation of atrial fibrillation.

  9. Edoxaban versus warfarin in patients with atrial fibrillation

    NARCIS (Netherlands)

    Giugliano, R.P.; Ruff, C.T.; Braunwald, E.; Murphy, S.A.; Wiviott, S.D.; Halperin, J.L.; Waldo, A.L.; Ezekowitz, M.D.; Weitz, J.I.; Spinar, J.; Ruzyllo, W.; Ruda, M.; Koretsune, Y.; Betcher, J.; Shi, M.; Grip, L.T.; Patel, S.P.; Patel, I.; Hanyok, J.J.; Mercuri, M.; Antman, E.M.; Verheugt, F.W.A.

    2013-01-01

    BACKGROUND: Edoxaban is a direct oral factor Xa inhibitor with proven antithrombotic effects. The long-term efficacy and safety of edoxaban as compared with warfarin in patients with atrial fibrillation is not known. METHODS: We conducted a randomized, double-blind, double-dummy trial comparing two

  10. Gene-gene Interaction Analyses for Atrial Fibrillation

    NARCIS (Netherlands)

    Lin, Honghuang; Mueller-Nurasyid, Martina; Smith, Albert V; Arking, Dan E; Barnard, John; Bartz, Traci M; Lunetta, Kathryn L; Lohman, Kurt; Kleber, Marcus E; Lubitz, Steven A; Geelhoed, Bastiaan; Trompet, Stella; Niemeijer, Maartje N; Kacprowski, Tim; Chasman, Daniel I; Klarin, Derek; Sinner, Moritz F; Waldenberger, Melanie; Meitinger, Thomas; Harris, Tamara B; Launer, Lenore J; Soliman, Elsayed Z; Chen, Lin Y; Smith, Jonathan D; Van Wagoner, David R; Rotter, Jerome I; Psaty, Bruce M; Xie, Zhijun; Hendricks, Audrey E; Ding, Jingzhong; Delgado, Graciela E; Verweij, Niek; van der Harst, Pim; Macfarlane, Peter W; Ford, Ian; Hofman, Albert; Uitterlinden, André; Heeringa, Jan; Franco, Oscar H; Kors, Jan A; Weiss, Stefan; Völzke, Henry; Rose, Lynda M; Natarajan, Pradeep; Kathiresan, Sekar; Kääb, Stefan; Gudnason, Vilmundur; Alonso, Alvaro; Chung, Mina K; Heckbert, Susan R; Benjamin, Emelia J; Liu, Yongmei; März, Winfried; Rienstra, Michiel; Jukema, J Wouter; Stricker, Bruno H; Dörr, Marcus; Albert, Christine M; Ellinor, Patrick T

    2016-01-01

    Atrial fibrillation (AF) is a heritable disease that affects more than thirty million individuals worldwide. Extensive efforts have been devoted to the study of genetic determinants of AF. The objective of our study is to examine the effect of gene-gene interaction on AF susceptibility. We performed

  11. Gene-gene Interaction Analyses for Atrial Fibrillation

    NARCIS (Netherlands)

    H. Lin (Honghuang); M. Mueller-Nurasyid; A.V. Smith (Albert Vernon); D.E. Arking (Dan); J. Barnard (John); T.M. Bartz (Traci M.); K.L. Lunetta (Kathryn); K. Lohman (Kurt); M.E. Kleber (Marcus); S.A. Lubitz (Steven); Geelhoed, B. (Bastiaan); S. Trompet (Stella); M.N. Niemeijer (Maartje); T. Kacprowski (Tim); D.I. Chasman (Daniel); Klarin, D. (Derek); M.F. Sinner (Moritz); M. Waldenberger (Melanie); T. Meitinger (Thomas); T.B. Harris (Tamara); Launer, L.J. (Lenore J.); E.Z. Soliman (Elsayed Z.); L. Chen (Lin); J.D. Smith (Jonathan); D.R. van Wagoner (David); Rotter, J.I. (Jerome I.); B.M. Psaty (Bruce); Xie, Z. (Zhijun); A.E. Hendricks (Audrey E.); Ding, J. (Jingzhong); G.E. Delgado (Graciela E.); N. Verweij (Niek); P. van der Harst (Pim); P.W. MacFarlane (Peter); I. Ford (Ian); A. Hofman (Albert); A.G. Uitterlinden (André); J. Heeringa (Jan); O.H. Franco (Oscar); J.A. Kors (Jan); Weiss, S. (Stefan); H. Völzke (Henry); L.M. Rose (Lynda); Natarajan, P. (Pradeep); S. Kathiresan (Sekar); S. Kääb (Stefan); V. Gudnason (Vilmundur); A. Alonso (Alvaro); M.K. Chung (Mina); S.R. Heckbert (Susan); E.J. Benjamin (Emelia); Y. Liu (Yongmei); W. März (Winfried); S.A. Rienstra; J.W. Jukema (Jan Wouter); B.H.Ch. Stricker (Bruno); M. Dörr (Marcus); C.M. Albert (Christine); P.T. Ellinor (Patrick)

    2016-01-01

    textabstractAtrial fibrillation (AF) is a heritable disease that affects more than thirty million individuals worldwide. Extensive efforts have been devoted to the study of genetic determinants of AF. The objective of our study is to examine the effect of gene-gene interaction on AF susceptibility.

  12. Micromechanical testing of single collagen type I fibrils

    NARCIS (Netherlands)

    Rijt, van der Joost Adrianus Johannes

    2004-01-01

    In this thesis the following subjects will be covered. In chapter 2 the current understanding of the structure and corresponding mechanical properties of collagen and its substructures will be reviewed. In chapter 3 the methodology to enable fixation and subsequent tensile testing of collagen fibril

  13. Mechanical model for a collagen fibril pair in extracellular matrix.

    Science.gov (United States)

    Chan, Yue; Cox, Grant M; Haverkamp, Richard G; Hill, James M

    2009-04-01

    In this paper, we model the mechanics of a collagen pair in the connective tissue extracellular matrix that exists in abundance throughout animals, including the human body. This connective tissue comprises repeated units of two main structures, namely collagens as well as axial, parallel and regular anionic glycosaminoglycan between collagens. The collagen fibril can be modeled by Hooke's law whereas anionic glycosaminoglycan behaves more like a rubber-band rod and as such can be better modeled by the worm-like chain model. While both computer simulations and continuum mechanics models have been investigated for the behavior of this connective tissue typically, authors either assume a simple form of the molecular potential energy or entirely ignore the microscopic structure of the connective tissue. Here, we apply basic physical methodologies and simple applied mathematical modeling techniques to describe the collagen pair quantitatively. We found that the growth of fibrils was intimately related to the maximum length of the anionic glycosaminoglycan and the relative displacement of two adjacent fibrils, which in return was closely related to the effectiveness of anionic glycosaminoglycan in transmitting forces between fibrils. These reveal the importance of the anionic glycosaminoglycan in maintaining the structural shape of the connective tissue extracellular matrix and eventually the shape modulus of human tissues. We also found that some macroscopic properties, like the maximum molecular energy and the breaking fraction of the collagen, were also related to the microscopic characteristics of the anionic glycosaminoglycan.

  14. Abnormal atrial activation in young patients with lone atrial fibrillation

    DEFF Research Database (Denmark)

    Holmqvist, Fredrik; Olesen, Morten S; Tveit, Arnljot

    2011-01-01

    Aims Patients with a history of atrial fibrillation (AF) have previously been shown to have altered atrial conduction, as seen non-invasively using signal-averaged P-wave analysis. However, little is known about the P-wave morphology in patients in the early phases of AF with structurally normal ...

  15. The Surprising Role of Amyloid Fibrils in HIV Infection.

    Science.gov (United States)

    Castellano, Laura M; Shorter, James

    2012-01-01

    Despite its discovery over 30 years ago, human immunodeficiency virus (HIV) continues to threaten public health worldwide. Semen is the principal vehicle for the transmission of this retrovirus and several endogenous peptides in semen, including fragments of prostatic acid phosphatase (PAP248-286 and PAP85-120) and semenogelins (SEM1 and SEM2), assemble into amyloid fibrils that promote HIV infection. For example, PAP248-286 fibrils, termed SEVI (Semen derived Enhancer of Viral Infection), potentiate HIV infection by up to 105-fold. Fibrils enhance infectivity by facilitating virion attachment and fusion to target cells, whereas soluble peptides have no effect. Importantly, the stimulatory effect is greatest at low viral titers, which mimics mucosal transmission of HIV, where relatively few virions traverse the mucosal barrier. Devising a method to rapidly reverse fibril formation (rather than simply inhibit it) would provide an innovative and urgently needed preventative strategy for reducing HIV infection via the sexual route. Targeting a host-encoded protein conformer represents a departure from traditional microbicidal approaches that target the viral machinery, and could synergize with direct antiviral approaches. Here, we review the identification of these amyloidogenic peptides, their mechanism of action, and various strategies for inhibiting their HIV-enhancing effects.

  16. High resolution spectroscopy reveals fibrillation inhibition pathways of insulin

    Science.gov (United States)

    Deckert-Gaudig, Tanja; Deckert, Volker

    2016-12-01

    Fibril formation implies the conversion of a protein’s native secondary structure and is associated with several neurodegenerative diseases. A better understanding of fibrillation inhibition and fibril dissection requires nanoscale molecular characterization of amyloid structures involved. Tip-enhanced Raman scattering (TERS) has already been used to chemically analyze amyloid fibrils on a sub-protein unit basis. Here, TERS in combination with atomic force microscopy (AFM), and conventional Raman spectroscopy characterizes insulin assemblies generated during inhibition and dissection experiments in the presence of benzonitrile, dimethylsulfoxide, quercetin, and β-carotene. The AFM topography indicates formation of filamentous or bead-like insulin self-assemblies. Information on the secondary structure of bulk samples and of single aggregates is obtained from standard Raman and TERS measurements. In particular the high spatial resolution of TERS reveals the surface conformations associated with the specific agents. The insulin aggregates formed under different inhibition and dissection conditions can show a similar morphology but differ in their β-sheet structure content. This suggests different aggregation pathways where the prevention of the β-sheet stacking of the peptide chains plays a major role. The presented approach is not limited to amyloid-related reasearch but can be readily applied to systems requiring extremely surface-sensitive characterization without the need of labels.

  17. Maßnahmen zur kontrollierten Generierung von organischen Nanopartikeln in einer übersättigten Gasströmung

    OpenAIRE

    Voigt, Tino

    2009-01-01

    Die vorliegende Arbeit befasst sich mit der Generierung von organischen Nanopartikeln in einer übersättigten Gasströmung. Als Versuchsmaterialien kamen Kupferphthalocyanin und Paliogen Rot L4120 zum Einsatz. Sie werden bereits erfolgreich in der Informations- und Kommunikationstechnologie als Bestandteil in Halbleiterbaugruppen oder organischen Leuchtdioden eingesetzt. Gerade in solchen Anwendungsgebieten ist eine hohe Reinheit der Materialien unerlässlich. Gasphasenprozesse bieten diesen Vor...

  18. Effekte einer Langzeit-Therapie mit Pramipexol oder Levodopa auf die [123I]FP-CIT SPECT in einem Mausmodell der Parkinson-Krankheit

    OpenAIRE

    Maurer, Lukas

    2015-01-01

    Die zuvor durchgeführte klinische Studie CALM-PD (ParkinsonStudyGroup, 2002) untersuchte den Effekt einer Langzeittherapie mit Levodopa oder Pramipexol auf das Fortschreiten der Parkinson-Krankheit mittels SPECT unter Verwendung des Dopamintransporter-Liganden [123I]β-CIT als Surrogat-Marker. Die [123I]β-CIT Bindung fiel in den Patienten, die Levodopa erhalten hatten, auf ein signifikant niedrigeres Niveau ab, als bei den Patiente...

  19. Dem Schreiben Raum geben : eine qualitative Untersuchung zum Einfluss von Angeboten der Peer Schreibberatung auf Regulationsprozesse beim Erstellen einer Abschlussarbeit an der Hochschule

    OpenAIRE

    2011-01-01

    Im Rahmen der vorliegenden Qualifizierungsarbeit von Jantje Witt werden drei Teilnehmende zu ihren Erfahrungen im "Schreibwohnzimmer" befragt. Das "Schreibwohnzimmer" ist eine Initiative der Peer Schreibberatung skript.um der Universität Bielefeld. Es bietet Studierenden Raum, an ihrer Abschlussarbeit zu arbeiten. Im Rahmen dieses Angebots treffen sich etwa 10 Schreibende in Gegenwart einer Peer Schreibtutorin einmalig an drei aufeinander folgenden Tagen. Dort haben sie, gerahmt von einem gem...

  20. Anlage einer Fertilitätsreserve bei nicht-medizinischen Indikationen („Social freezing“: Techniken und kritische Bewertung

    Directory of Open Access Journals (Sweden)

    von Wolff M

    2013-01-01

    Full Text Available Die Fortschritte der Reproduktionsbiologie und -medizin eröffnen inzwischen die Möglichkeit der Anlage einer Fertilitätsreserve. Da diese Maßnahme bereits bei Frauen vor zytotoxischen Therapien, d. h. bei einer medizinischen Indikation, in vielen Fällen empfohlen und durchgeführt wird, rückt diese Möglichkeit auch bei nicht-medizinischen Indikationen („Social freezing“ zunehmend in den Fokus. Technisch möglich ist inzwischen die Kryokonservierung unfertilisierter Oozyten. Ebenso ist die Kryokonservierung von Ovargewebe eine Option. Die Chancen, mit diesen Maßnahmen später eine Schwangerschaft zu erzielen, sind schwer abschätzbar, dürften aber zwischen 30 und 60 % liegen, wenn diese mit ≤ 35 Jahren bei einer guten Ovarreserve durchgeführt werden. Social freezing ist technisch relativ einfach, die ethische Dimension dieser Maßnahmen ist jedoch komplex. Ethiker betonen das Recht der Frau auf Autonomie, Geburtshelfer warnen vor Schwangerschaften im höheren Alter mit Risiken für Mutter und Kind. Ob durch diese Maßnahmen die ethisch ebenfalls problematische (oft anonyme Oozytenspende z. T. verhindert oder – im Gegensatz – sogar gefördert wird, ist offen. Das Netzwerk FertiPROTEKT (a href="http://www.fertiprotekt.com"www.fertiprotekt.com/a versucht, mit Empfehlungen, einer Selbstverpflichtung der 85 Mitgliedszentren und der Anlage eines Registers die Anwendung dieser Maßnahmen zu steuern.