Publications by authors named "Jens Schwarz"

Purpose:  To observe the technical and clinical outcome as well as safety of CT fluoroscopy-guided drain placement in the multimodal clinical complication management of superinfected gastric leakage after sleeve gastrectomy.

Materials And Methods:  All consecutive patients who underwent CT fluoroscopy-guided drain placement to treat superinfected postoperative leakage after sleeve gastrectomy in our department between 2007 and 2014 were included in this retrospective study. All interventions were performed on a 16- or 128-row CT scanner under intermittent CT fluoroscopy guidance (15-25 mAs, 120 kV).

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Background: Contemporary resuscitation guidelines for basic life support recommend an immediate onset of cardiac compressions in case of cardiac arrest followed by rescue breaths. Effective ventilation is often omitted due to fear of doing harm and fear of infectious diseases. In order to improve ventilation a pre-stage of an automatic respirator was developed for use by laypersons.

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Background In unclear pancreatic lesions, a tissue sample can confirm or exclude the suspected diagnosis and help to provide an optimal treatment strategy to each patient. To date only one small study reported on the outcome of computed tomography (CT) fluoroscopy-guided biopsies of the pancreas. Purpose To evaluate technical success and diagnostic rate of all CT fluoroscopy-guided core biopsies of the pancreas performed in a single university center during a 10-year period.

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Purpose: This study was designed to assess technical success and complications in patients with high-risk soft tissue sarcomas undergoing CT fluoroscopy-guided closed-tip catheter placement before treatment with combined chemotherapy and regional hyperthermia.

Materials And Methods: This retrospective study comprised all patients referred for insertion of closed-tip catheters for the introduction of thermometry probes before regional hyperthermia treatment at a single university centre from 2010 to 2015. Catheter placements were performed under local anaesthesia and intermittent CT fluoroscopy guidance.

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A model for nonlinear optical propagation is cast into a split-step numerical framework via a variable stencil-size Crank-Nicolson finite-difference method for the linear step and a choice of two different nonlinear integration schemes for the nonlinear step. The model includes Kerr, Raman scattering, and ionization effects (as well as linear and nonlinear shock, diffraction, and dispersion). We demonstrate the practical importance of numerical effects when interpreting computational studies of high-intensity optical pulse propagation in physical materials.

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Background: Vegan and vegetarian diets could overcome many diseases of civilization. This study examines whether a whole food vegan diet with Nori algae and wild mushrooms can provide a sufficient quantity of critical nutrients.

Methods: Five blood samples (Baseline to Time 5) were taken over eight months from 75 subjects (10 vegans without B12 supplementation who consumed Nori algae and wild mushrooms, 20 vegans with supplementation, 40 vegetarians, 5 meat-eaters).

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A wavefront sensor has been used to measure the Kerr nonlinear focal shift of a high intensity ultrashort pulse beam in a focusing beam geometry while accounting for the effects of plasma-defocusing. It is shown that plasma-defocusing plays a major role in the nonlinear focusing dynamics and that measurements of Kerr nonlinearity and ionization are coupled. Furthermore, this coupled effect leads to a novel way that measures the laser ionization rates in air under atmospheric conditions as well as Kerr nonlinearity.

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Experiments dedicated to the characterization of plasma mirrors with a high energy, single shot short-pulse laser were performed at the 100 TW target area of the Z-Backlighter Facility at Sandia National Laboratories. A suite of beam diagnostics was used to characterize a high energy laser pulse with a large aperture through focus imaging setup. By varying the fluence on the plasma mirror around the plasma ignition threshold, critical performance parameters were determined and a more detailed understanding of the way in which a plasma mirror works could be deduced.

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We compare designs and laser-induced damage thresholds (LIDTs) of hafnia/silica antireflection (AR) coatings for 1054 nm or dual 527 nm/1054 nm wavelengths and 0° to 45° angles of incidence (AOIs). For a 527 nm/1054 nm, 0° AOI AR coating, LIDTs from three runs arbitrarily selected over three years are ∼20 J/cm2 or higher at 1054 nm and <10 J/cm2 at 527 nm. Calculated optical electric field intensities within the coating show two intensity peaks for 527 nm but not for 1054 nm, correlating with the lower (higher) LIDTs at 527 nm (1054 nm).

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An optical surface of variable concave parabolic shape and a clear aperture of 30 mm was created using two rings to deform a flat 50.8 mm diameter mirror. The deformable mirror assembly was modeled using finite element analysis software as well as analytical solutions.

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