78 research outputs found

    Premature Ventricular Contractions Causing Sinus Arrhythmia and Alternating P-R Prolongation

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    Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/73731/1/j.1540-8167.2007.01020.x.pd

    Modelling of the transport of energy through thermal glazings

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    Es werden sowohl analytische als auch numerische Verfahren zur Berechnung der WĂ€rmeverluste von Verglasungen vorgestellt, wobei alle am Energietransport beteiligten Prozesse, die WĂ€rmeleitung, die thermisch getriebenen Konvektionsströmungen und die infrarote Strahlungswechselwirkung, korrekt und vollstĂ€ndig berĂŒcksichtigt werden. Mit Hilfe numerischer Strömungssimulation werden Verglasungen systematisch hinsichtlich der FĂŒllgasart, der Infrarotverspiegelung, der Einbaulage und des Scheibenabstandes sowie der Anzahl der GaszwischenrĂ€ume (Zwei-, Drei- und Vierscheiben-Verglasung) untersucht und verglichen. Die AbhĂ€ngigkeit des k-Wertes von den Temperaturen der angrenzenden Klimate (AtmosphĂ€re und Innenraum) wird dargestellt.The aim of this work is to calculate the heat losses of thermal glazings. Conduction, radiation and convection are described in detail. Both analytical and numerical approaches are presented. Using a program for Computational Fluid Dynamics (CFD) thermal glazings are investigated systematically. The influence of IR-reflecting coatings, kind of gas-filling, pane distance and number of panes is studied. Furthermore a dependence of the u-value on the temperature difference between room and atmosphere is described for certain gas-fillings

    A Wide Complex Tachycardia: What is the Mechanism?

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    Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/73868/1/j.1540-8167.2007.01000.x.pd

    Reviews

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    Reviews Carolyn E. Hill. Token Professionals and Master Critics: A Critique of Orthodoxy in Literary Studies. (James Sosnoski, 1994). Michael Kuhne. Releasing the Imagination: Essays on Education, the Arts, and Social Change. (Maxine Greene, 1995). Felicia M. Briscoe. Artwork of the Mind: An Interdisciplinary Description of Insight and the Search for it in Student Writing. (Mary M. Murray, 1996). Hanna Berger. If You Want to Write: A Book about Art, Independence and Spirit. (Brenda Ueland, 1997). Candace Walworth. The Rag and Bone Shop of the Heart: Poems for Men. (Robert Bly, James Hillman, Michael Meade, Eds., 1992)

    Ulocuplumab (BMS-936564 / MDX1338): a fully human anti-CXCR4 antibody induces cell death in chronic lymphocytic leukemia mediated through a reactive oxygen species-dependent pathway.

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    The CXCR4 receptor (Chemokine C-X-C motif receptor 4) is highly expressed in different hematological malignancies including chronic lymphocytic leukemia (CLL). The CXCR4 ligand (CXCL12) stimulates CXCR4 promoting cell survival and proliferation, and may contribute to the tropism of leukemia cells towards lymphoid tissues. Therefore, strategies targeting CXCR4 may constitute an effective therapeutic approach for CLL. To address that question, we studied the effect of Ulocuplumab (BMS-936564), a fully human IgG4 anti-CXCR4 antibody, using a stroma--CLL cells co-culture model. We found that Ulocuplumab (BMS-936564) inhibited CXCL12 mediated CXCR4 activation-migration of CLL cells at nanomolar concentrations. This effect was comparable to AMD3100 (Plerixafor--Mozobil), a small molecule CXCR4 inhibitor. However, Ulocuplumab (BMS-936564) but not AMD3100 induced apoptosis in CLL at nanomolar concentrations in the presence or absence of stromal cell support. This pro-apoptotic effect was independent of CLL high-risk prognostic markers, was associated with production of reactive oxygen species and did not require caspase activation. Overall, these findings are evidence that Ulocuplumab (BMS-936564) has biological activity in CLL, highlight the relevance of the CXCR4-CXCL12 pathway as a therapeutic target in CLL, and provide biological rationale for ongoing clinical trials in CLL and other hematological malignancies

    Mapping and Ablation of Frequent Post-Infarction Premature Ventricular Complexes

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    Mapping of Post-Infarction PVCs .  Introduction: Premature ventricular complexes (PVCs) occur frequently in patients with heart disease. The sites of origin of PVCs in patients with prior myocardial infarction and the response to catheter ablation have not been systematically assessed. Methods and Results: In 28 consecutive patients (24 men, age 60 ± 10, ejection fraction [EF] 0.37 ± 0.14) with remote myocardial infarction referred for catheter ablation of symptomatic refractory PVCs, the PVCs were mapped by activation mapping or pace mapping using an irrigated-tip catheter in conjunction with an electroanatomic mapping system. The site of origin (SOO) was classified as being within low-voltage (scar) tissue (amplitude ≀1.5 mV) or tissue with preserved voltage (>1.5 mV). The SOO was confined to endocardial scar tissue in 24/28 patients (86%). The SOO was outside of scar in 3 patients and could not be identified in 1 patient. At the SOO, local endocardial activation preceded the PVC by 46 ± 19 ms, and the electrogram amplitude during sinus rhythm was 0.48 ± 0.34 mV. The PVCs were effectively ablated in 25/28 patients (89%), resulting in a decrease in PVC burden on a 24-hour Holter monitor from 15.6 ± 12.3% to 2.4 ± 4.2% (P < 0.001). The SOO most often was confined to scar tissue located in the left ventricular septum and the papillary muscles. Conclusion: Similar to post-infarction ventricular tachycardia, PVCs after remote myocardial infarction most often originate within scar tissue. Catheter ablation of these PVCs has a high-success rate. (J Cardiovasc Electrophysiol, Vol. 21, pp. 1002-1008, September 2010)Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/79266/1/j.1540-8167.2010.01771.x.pd

    Fibre Optic Sensors for the Structural Health Monitoring of Building Structures

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    In this work different fibre optic sensors for the structural health monitoring of civil engineering structures are reported. A fibre optic crack sensor and two different fibre optic moisture sensors have been designed to detect the moisture ingress in concrete based building structures. Moreover, the degeneration of the mechanical properties of optical glass fibre sensors and hence their long-term stability and reliability due to the mechanical and chemical impact of the concrete environment is discussed as well as the advantage of applying a fibre optic sensor system for the structural health monitoring of sewerage tunnels is demonstrated

    Durability of functionalized carbon structures with optical fiber sensors in a highly alkaline concrete environment.

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    The paper presents an investigation into the durability of functionalized carbon structures (FCS) in a highly alkaline concrete environment. First, the suitability of optical fibers with different coatings—i.e., acrylate, polyimide, or carbon—for the FCS was investigated by subjecting fibers with different coatings to micro/macro bending and a 5% sodium hydroxide (NaOH) (pH 14) solution. Then, the complete FCS was also subjected to a 5% NaOH solution. Finally, the effects of spatial variation of the fiber embedded in the FCS and the bonding strength between the fiber and FCS was evaluated using different configurations —i.e., fiber integrated into FCS in a straight line and/or with offsets. All three coatings passed the micro/macro bending tests and show degradation after alkaline exposure, with the carbon coating showing least degradation. The FCS showed relative stability after exposure to 5% NaOH. The optimum bonding length between the optical fiber and the carbon filament was found to be ≄150 mm for adequate sensitivity

    Evaluating the Performance of Functionalized Carbon Structures with Integrated Optical Fiber Sensors under Practical Conditions

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    An Optical Frequency Domain Reflectometry (OFDR) based fiber optic sensor scheme “embedded” in concrete for the purpose of structural health monitoring (SHM) of carbon concrete composites (C3) is presented. The design, while strengthening the concrete structure, also aims to monitor common SHM parameters such as strain and cracks. This was achieved by weaving the carbon fiber together with optical fiber, based on a specialized technique that uses an embroidery setup where both the carbon and optical fiber are woven on a water dissolvable polymer substrate. The performance of the sensing scheme was characterized in-situ utilizing the OFDR based technique and the results presented. The sensors embedded on a custom made concrete block were subjected to varying strain via a three point bending test to destruction and the results discussed. The intended dual-achievement of the scheme thus proposed in SHM and strengthening the C3 is demonstrated. The suitability of the OFDR scheme for C3 is combined with a fibre Bragg grating (FBG)-based approach, and discussed in detail
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