132 research outputs found

    An indicator of sudden cardiac death during brief coronary occlusion: electrocardiogram QT time and the role of collaterals

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    Aims The coronary collateral circulation has a beneficial role regarding all-cause and cardiac mortality. Hitherto, the underlying mechanism has not been clarified. The aim of this prospective study was to assess the effect of the coronary collateral circulation on electrocardiogram (ECG) QTc time change during short-term myocardial ischaemia. Methods and results A total of 150 patients (mean age 63 ± 11 years, 38 women) were prospectively included in this study. An ECG was recorded at baseline and during a standardized 1 min coronary balloon occlusion. QT interval was measured before, during, and after balloon occlusion and was corrected for heart rate (QTc). Simultaneously obtained collateral flow index (CFI), expressing collateral flow relative to normal anterograde flow, was determined based on intracoronary pressure measurements. During occlusion of the left anterior descending coronary artery mean QTc interval increased from 422 ± 33 to 439 ± 36 ms (P < 0.001), left circumflex occlusion led to an increase from 414 ± 32 to 427 ± 27 ms (P < 0.001). QTc was not influenced by occlusion of the right coronary artery (RCA) (417 ± 35 and 415 ± 34 ms, respectively; P = 0.863). QTc change during occlusion of the left coronary artery was inversely correlated with CFI (R2 = 0.122, P = 0.0002). Conclusion Myocardial ischaemia leads to QT prolongation during a controlled 1 min occlusion of the left, but not the RCA. QT prolongation is inversely related to collateral function indicating a protective mechanism of human coronary collaterals against cardiac deat

    Open reduction and internal fixation versus casting for highly comminuted and intra-articular fractures of the distal radius (ORCHID): protocol for a randomized clinical multi-center trial

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    <p>Abstract</p> <p>Background</p> <p>Fractures of the distal radius represent the most common fracture in elderly patients, and often indicate the onset of symptomatic osteoporosis. A variety of treatment options is available, including closed reduction and plaster casting, K-wire-stabilization, external fixation and open reduction and internal fixation (ORIF) with volar locked plating. The latter is widely promoted by clinicians and hardware manufacturers. Closed reduction and cast stabilization for six weeks is a simple, convenient, and ubiquitously available intervention. In contrast, ORIF requires hospitalization, but allows for functional rehabilitation.</p> <p>Given the lack of randomized controlled trials, it remains unclear whether ORIF leads to better functional outcomes one year after injury than closed reduction and casting.</p> <p>Methods/Design</p> <p>ORCHID (Open reduction and internal fixation versus casting for highly comminuted intra-articular fractures of the distal radius) is a pragmatic, randomized, multi-center, clinical trial with two parallel treatment arms. It is planned to include 504 patients in 15 participating centers throughout Germany over a three-year period. Patients are allocated by a central web-based randomization tool.</p> <p>The primary objective is to determine differences in the Short Form 36 (SF-36) Physical Component Score (PCS) between volar locked plating and closed reduction and casting of intraarticular, comminuted distal radius fractures in patients > 65 years of age one year after the fracture. Secondary outcomes include differences in other SF-36 dimensions, the EuroQol-5D questionnaire, the Disability of the Arm, Shoulder, and Hand (DASH) instrument. Also, the range of motion in the affected wrist, activities of daily living, complications (including secondary ORIF and revision surgery), as well as serious adverse events will be assessed. Data obtained during the trial will be used for later health-economic evaluations. The trial architecture involves a central statistical unit, an independent monitoring institute, and a data safety monitoring board. Following approval by the institutional review boards of all participating centers, conduct and reporting will strictly adhere to national and international rules, regulations, and recommendations (e.g., Good Clinical Practice, data safety laws, and EQUATOR/CONSORT proposals)</p> <p>Discussion</p> <p>To our knowledge, ORCHID is the first multicenter RCT designed to assess quality of life and functional outcomes following operative treatment compared to conservative treatment of complex, intra-articular fractures of the distal radius in elderly patients. The results are expected to influence future treatment recommendations and policies on an international level.</p> <p>Trial registration</p> <p>ISRCTN: <a href="http://www.controlled-trials.com/ISRCTN76120052">ISRCTN76120052</a></p> <p>Registration date: 31.07.2008; Randomization of first patient: 15.09.2008</p

    Instantaneous coronary collateral function during supine bicycle exercise

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    Aims The instantaneous response of the collateral circulation to isometric physical exercise in patients with non-occlusive coronary artery disease (CAD) is not known. Methods and results Thirty patients (age 59 ± 9 years) undergoing percutaneous coronary intervention because of stable CAD were included in the study. Collateral function was determined before and during the last minute of a 6 min protocol of supine bicycle exercise during radial artery access coronary angiography. Collateral flow index (CFI, no unit) was determined as the ratio of mean distal coronary occlusive to mean aortic pressure both subtracted by central venous pressure. To avoid confounding due to recruitment of coronary collaterals by repetitive balloon occlusions, patients were randomly assigned to a group ‘rest first' with CFI measurement during rest followed by CFI during exercise, and to a group ‘exercise first' with antecedent CFI measurement during exercise before CFI at rest. Simultaneously, coronary collateral conductance (occlusive myocardial blood flow per aorto-coronary pressure drop) was determined by myocardial contrast echocardiography in the last 10 consecutive patients. Overall, CFI increased from 0.168 ± 0.118 at rest to 0.262 ± 0.166 during exercise (P = 0.0002). The exercise-induced change in CFI did not differ statistically in the two study groups. Exercise-induced CFI reserve (CFI during exercise divided by CFI at rest) was 2.2 ± 1.8. Overall, rest to peak bicycle exercise change of coronary collateral conductance was from 0.010 ± 0.010 to 1.109 ± 0.139 mL/min/100 mmHg (P < 0.0001); the respective change was similar in both groups. Conclusion In patients with non-occlusive CAD, collateral flow instantaneously doubles during supine bicycle exercise as compared with the resting state. ClinicalTrials.gov Identifier: NCT0094705

    Swiss Marketing Leadership Studie 2015 : Status Quo und Trends in Schweizer Unternehmen

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    Marketing ändert sich fundamental und sollte in modernen Unternehmen eine steuernde Funktion in Richtung Kunden- und Marktorientierung einnehmen. Vor diesem Hintergrund entschied sich das Institut für Marketing Management der ZHAW School of Management and Law zu einer Fusion der beiden bewährten Studienformate «Swiss CRM» und «Swiss Product Management» und veröffentlicht erstmalig die «Swiss Marketing Leadership Studie»

    Paediatric thyroid surgery is safe - experiences at a tertiary surgical centre.

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    PRINCIPLES Thyroidectomy in children is rare and mostly performed because of thyroid neoplasms. The aim of this study based on prospective data acquisition was to evaluate whether thyroid surgery in children can be performed as safely as in adults when undertaken by a team of adult endocrine surgeons and paediatric surgeons. METHODS Between 2002 and 2012, 36 patients younger than 18 years underwent surgery for thyroid gland pathologies. All surgical procedures were performed by an experienced endocrine surgeon and a paediatric surgeon. Baseline demographic data, surgical procedure, duration of operation, length of hospital stay, and postoperative morbidity and mortality were analysed. RESULTS The median age of all patients was 13 years (range 2-17 years), with predominantly female gender (n = 30, 83%). The majority of operations were performed because of benign thyroid disease (n = 27, 75%) and only a minority because of malignancy or genetic abnormality with predisposition for malignant transformation (MEN) (n = 9, 25%). Total thyroidectomy was performed in the majority of the patients (n = 24, 67%). The median duration of the surgical procedure was 153 minutes (range 90-310 minutes). The median hospital stay was 5 days (3-1 days). One patient developed persistent hypoparathyroidism after neck dissection due to cancer. One persistent and two temporary recurrent nerve palsies occurred. CONCLUSION This study demonstrated that paediatric thyroidectomy is safe as performed by this team of endocrine and paediatric surgeons, with acceptable morbidity even when total thyroidectomy was performed in the case of benign disease

    Probing Crystallinity and Grain Structure of 2D Materials and 2D-Like Van der Waals Heterostructures by Low-Voltage Electron Diffraction

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    4D scanning transmission electron microscopy (4D-STEM) is a powerful method for characterizing electron-transparent samples with down to sub-Ångstrom spatial resolution. 4D-STEM can reveal local crystallinity, orientation, grain size, strain, and many more sample properties by rastering a convergent electron beam over a sample area and acquiring a transmission diffraction pattern (DP) at each scan position. These patterns are rich in information about the atomic structure of the probed volume, making this technique a potent tool to characterize even inhomogeneous samples. 4D-STEM can also be used in scanning electron microscopes (SEMs) by placing an electron-sensitive camera below the sample. 4D-STEM-in-SEMs is ideally suited to characterize 2D materials and 2D-like van der Waals heterostructures (vdWH) due to their inherent thickness of a few nanometers. The lower accelerating voltage of SEMs leads to strong scattering even from monolayers. The large field of view and down to sub-nm spatial resolution of SEMs are ideal to map properties of the different constituents of 2D-like vdWH by probing their combined sample volume. A unique 4D-STEM-in-SEM system is applied to reveal the single crystallinity of MoS2 exfoliated with gold-mediation as well as the crystal orientation and coverage of both components of a C60/MoS2 vdWH are determined

    Eine service-orientierte Grid-Infrastruktur zur Unterstützung medienwissenschaftlicher Filmanalyse

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    Innerhalb des von der DFG (SFB/FK 615) geförderten Projektes „Methoden und Werkzeuge zur rechnergestützten medienwissenschaftlichen Analyse“ werden Verfahren und Werkzeuge entwickelt, die Medienwissenschaftler bei der Analyse von audiovisuellen Daten unterstützen sollen. In diesem Beitrag wird die Videoanalyse-Software Videana vorgestellt, die eigens entwickelte Verfahren und Konzepte zur Analyse von audio-visuellen Daten beinhaltet. Weiterhin werden Forschungsarbeiten bezüglich einer Grid-Infrastruktur zur Unterstützung medienwissenschaftlicher Forschungsarbeiten sowie zur service-orientierten Analyse von Multimediadaten präsentiert. So verfügt Videana beispielsweise über eine integrierte Grid-Anbindung und erlaubt Mitgliedern einer virtuellen Organisation, rechenintensive Analyseaufgaben auf externen Rechenressourcen auszuführen

    Instantaneous coronary collateral function during supine bicycle exercise

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    The instantaneous response of the collateral circulation to isometric physical exercise in patients with non-occlusive coronary artery disease (CAD) is not known

    von der Transaktion zur Beziehung. Crossing Borders

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    StudieDie Swiss CRM Studie 2014 befasst sich mit dem Schwerpunktthema kooperatives CRM. Auch dieses Jahr umfasst die Studie den Status Quo sowie die Trends des CRM in der Schweiz
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