879 research outputs found

    Snare technique for coronary sinus cannulation in cardiac resynchronization therapy

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    PURPOSE Biventricular pacing is a mainstay of therapy for patients with heart failure. However, lead implantations may fail due to anatomical reasons including the impossibility of coronary sinus cannulation. METHODS AND RESULTS A dual approach from the subclavian vein using a snare through a sheath and from the femoral vein using a steerable electrophysiology catheter was performed. Once the snare hooked the catheter, the latter was advanced into the coronary sinus and finally, the sheath could also be advanced in an "over-the-wire" technique. CONCLUSION The snare technique for coronary sinus cannulation offers a "bail-out" strategy for left ventricular lead implantation

    Reconstruction and Dissection of the Entire Human Visual Pathway Using Diffusion Tensor MRI

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    The human visual system comprises elongated fiber pathways that represent a serious challenge for diffusion tensor imaging (DTI) and fiber tractography: while tracking of frontal fiber bundles may be compromised by the nearby presence of air-filled cavities, nerves, and eye muscles, the anatomic courses of the three main fiber bundles of the optic radiation are subject to pronounced inter-subject variability. Here, tractography of the entire visual pathway was achieved in six healthy subjects at high spatial accuracy, that is, at 1.8 mm isotropic spatial resolution, without susceptibility-induced distortions, and in direct correspondence to anatomic MRI structures. Using a newly developed diffusion-weighted single-shot STEAM MRI sequence, we were able to track the thin optic nerve including the nasal optic nerve fibers, which cross the optic chiasm, and to dissect the optic radiation into the anterior ventral bundle (Meyer's loop), the central bundle, and the dorsal bundle. Apart from scientific applications these results in single subjects promise advances in the planning of neurosurgical procedures to avoid unnecessary damage to the visual fiber system

    Integrated environmental and economic assessment of current and future fuel cell vehicles

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    Light-duty vehicles contribute considerably to global greenhouse gas emissions. Fuel cell vehicles (FCVs) may play a key role in mitigating these emissions without facing the same limitations in range and refueling time as battery electric vehicles (BEVs). In this study, we assess the environmental impacts and costs of a polymer electrolyte membrane fuel cell system (FCS) for use in light-duty FCVs and integrate these results into a comparative evaluation between FCVs, BEVs, and internal combustion engine vehicles (ICEVs).Swisselectric ResearchSwiss Competence Centre for Energy and MobilitySwiss Petroleum Associatio

    Energie-und Elektronenübertragungen in multichromophoren peri-Arylenen

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    Energie-und Elektronenübertragungen in multichromophoren peri-Arylenen

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    Theories of scanning probe microscopes at the atomic scale

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    Significant progress has been made both in experimentation and in theoretical modeling of scanning probe microscopy. The theoretical models used to analyze and interpret experimental scanning probe microscope (SPM) images and spectroscopic data now provide information not only about the surface, but also the probe tip and physical changes occurring during the scanning process. The aim of this review is to discuss and compare the present status of computational modeling of two of the most popular SPM methods—scanning tunneling microscopy and scanning force microscopy—in conjunction with their applications to studies of surface structure and properties with atomic resolution. In the context of these atomic-scale applications, for the scanning force microscope (SFM), this review focuses primarily on recent noncontact SFM (NC-SFM) results. After a brief introduction to the experimental techniques and the main factors determining image formation, the authors consider the theoretical models developed for the scanning tunneling microscope (STM) and the SFM. Both techniques are treated from the same general perspective of a sharp tip interacting with the surface—the only difference being that the control parameter in the STM is the tunneling current and in the SFM it is the force. The existing methods for calculating STM and SFM images are described and illustrated using numerous examples, primarily from the authors' own simulations, but also from the literature. Theoretical and practical aspects of the techniques applied in STM and SFM modeling are compared. Finally, the authors discuss modeling as it relates to SPM applications in studying surface properties, such as adsorption, point defects, spin manipulation, and phonon excitation.Peer reviewe

    Housing and management factors and breed predisposition for haemorrhagic bowel syndrome in swine.

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    BACKGROUND Haemorrhagic bowel syndrome (HBS) is a sporadically occurring disorder characterized by sudden death in pigs in combination with a pale and bloated carcass with no prior signs of disease. Most often HBS is affecting fattening pigs. Due to the good general health and performance before death as well as the time point of disease shortly prior to slaughter, this syndrome means a significant economic impact for the farm and is a major animal welfare concern. Furthermore, the cause or the causing agents have not yet been identified even though it is a worldwide known problem. The aim of this study was to detect possible risk factors for the occurrence of HBS with the focus on risk factors on herd level. RESULTS Management and feeding strategies of 97 Swiss fattening herds with high and low HBS incidence were assessed and examined to identify risk factors for the disease. Having only pigs sired by the PREMO® breed in the herd showed to be a significant risk factor for HBS (Odds Ratio (OR) = 147) as compared to having other breeds or a mixture of multiple breeds. Furthermore, pigs from two or more origins per batch compared to having only one origin per batch significantly increased the disease risk (OR = 52). Farms with 1 decimetre greater feeding place width per finisher pig have a lower HBS incidence (OR = 0.07). The frequency of cleaning of the distribution pipes (split up into categories, e.g. once a month) was associated with being a HBS case farm (p < 0.05). CONCLUSION The four factors identified in this study for the occurrence of HBS represent different aspects of the environment and management. This leads to the assumption that it is a multifactorial syndrome and a thorough examination of each herd individually is necessary to mitigate disease risk. This study suggests that part of the susceptibility to HBS is genetically determined. The reduction of HBS in the herd should be the main objective to improve the economic status of the herd and improve animal welfare

    Binary Fluorescence Labeling for the Recovery of Polymeric Materials for Recycling

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    Fluorescent perylene derivatives for the invisible digital coding of polymers were reported where a binary combination of fluorescent doping allows the unambiguous identification of the polymers for sorting. The mono-material recovery of the polymeric materials is an important prerequisite for the high-performance application of recycled material and was enabled by the application of optical methods
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