Der Einfluss von Eisenmangel auf die Schilddrüsenfunktion

Ein kausaler Zusammenhang zwischen dem Eisenmangel und einer beeinträchtigten Schild-drüsenfunktion wurde in Humanstudien und im Rattenmodell belegt. Die vorliegende Studie sollte klären, ob ein Eisenmangel auch für die Schilddrüsenfunktion bei Patienten in Deutsch-land von Bedeutung ist. Hierzu wurden in einer retrospektiven Studie 188 euthyreote Schilddrüsepatienten einer en-dokrinologischen Universitätsambulanz in Deutschland anhand des Serum-Ferritin-Spiegels in eine Gruppe 30 µg/l eingeteilt und fT4, fT3 und TSH ausgewertet. Ausgeschlossen wurden Patienten mit schweren Allgemeinerkrankungen, Diabetes mellitus und Nierenerkrankungen sowie solche mit floriden Schilddrüsenerkrankungen, z.B. florider Autoimmunthyreoiditis oder Hyperthyreose. fT3 und fT4 waren in der Niedrig-Ferritin-Gruppe signifikant niedriger als in der Kontroll-gruppe ohne Eisenmangel. Die beiden Gruppen unterschieden sich nicht im TSH. Es zeigten sich schwache signifikante Korrelationen zwischen Serum-Ferritin und fT3 (p<0,001; r=0,26) bzw. fT4 (p<0,01; r=0,213). Zwischen Serum-Ferritin und TSH bestand keine signifikante Korrelation. Unsere Ergebnisse belegen, dass Eisenmangel den Schilddrüsenhormon-Metabolismus beein-trächtigt und auch in Deutschland bedeutend ist. Die Labordiagnostik sollte deshalb bei Schilddrüsenpatienten Serum-Ferritin beinhalten. Ab einem Wert < 30 µg/l ist eine Eisensub-stitution sinnvoll

Focal subarachnoid haemorrhage mimicking transient ischaemic attack - do we really need MRI in the acute stage?

Background: Acute non-traumatic focal subarachnoid haemorrhage (fSAH) is a rare transient ischaemic attack (TIA)-mimic. MRI is considered to be indispensable by some authors in order to avoid misdiagnosis, and subsequent improper therapy. We therefore evaluated the role of CT and MRI in the diagnosis of fSAH patients by comparing our cases to those from the literature. Methods: From 01/2010 to 12/2012 we retrospectively identified seven patients with transient neurological episodes due to fSAH, who had received unenhanced thin-sliced multiplanar CT and subsequent MRI within 3 days on a 1.5 T scanner. MRI protocol included at least fast-field-echo (FFE), diffusion-weighted imaging (DWI), T2-weighted fluid-attenuated inversion recovery (FLAIR) and time-of-flight (TOF) MRA sequences. By using MRI as gold-standard, we re-evaluated images and data from recent publications regarding the sensitivity to detect fSAH in unenhanced CT. Results: fSAH was detected by CT and by FFE and FLAIR on MRI in all of our own cases. However, DWI and T2w-spinecho sequences revealed fSAH in 3 of 7 and 4 of 6 cases respectively. Vascular imaging was negative in all cases. FFE-MRI revealed additional multiple microbleeds and superficial siderosis in 4 of 7 patients and 5 of 7 patients respectively. Including data from recently published literature CT scans delivered positive results for fSAH in 95 of 100 cases (95%), whereas MRI was positive for fSAH in 69 of 69 cases (100%). Conclusions: Thin-sliced unenhanced CT is a valuable emergency diagnostic tool to rule out intracranial haemorrhage including fSAH in patients with acute transient neurological episodes if immediate MRI is not available. However, MRI work-up is crucial and mandatorily has to be completed within the next 24-72 hours

Neue Herausforderungen für die Mobilität

NEUE HERAUSFORDERUNGEN FÜR DIE MOBILITÄT Neue Herausforderungen für die Mobilität / Frehn, Michael (Rights reserved) ( -

Orthorectification of helicopter-borne high resolution experimental burn observation from infra red handheld imagers

To pursue the development and validation of coupled fire-atmosphere models, the wildland fire modeling community needs validation data sets with scenarios where fire-induced winds influence fire front behavior, and with high temporal and spatial resolution. Helicopter-borne infrared thermal cameras have the potential to monitor landscape-scale wildland fires at a high resolution during experimental burns. To extract valuable information from those observations, three-step image processing is required: (a) Orthorectification to warp raw images on a fixed coordinate system grid, (b) segmentation to delineate the fire front location out of the orthorectified images, and (c) computation of fire behavior metrics such as the rate of spread from the time-evolving fire front location. This work is dedicated to the first orthorectification step, and presents a series of algorithms that are designed to process handheld helicopter-borne thermal images collected during savannah experimental burns. The novelty in the approach lies on its recursive design, which does not require the presence of fixed ground control points, hence relaxing the constraint on field of view coverage and helping the acquisition of high-frequency observations. For four burns ranging from four to eight hectares, long-wave and mid infra red images were collected at 1 and 3 Hz, respectively, and orthorectified at a high spatial resolution (<1 m) with an absolute accuracy estimated to be lower than 4 m. Subsequent computation of fire radiative power is discussed with comparison to concurrent space-borne measurementsPeer ReviewedPostprint (published version

Multi-parameter improvement method for (micro-) structural properties of high performance ceramics

Many pH-measurement electrodes rely on porous diaphragms to create a liquid electrolyte junction between reference-electrolyte and the fluid to be measured. In field applications, the diaphragm is required to meet partly contradictory improvement criteria. To minimize measurement errors and to ensure durability of the measurement device, the diaphragm is supposed to maximize electrolyte conductivity and reference-electrolyte outflow velocity, while simultaneously minimizing reference electrolyte flow rate. The task of optimizing the overall performance of this small piece of ceramics has lead to the development of a novel multi-parameter improvement scheme for its (micro-) structural design. The method encompasses the consideration of microscopic material design parameters, such as porosity, pore-tortuosity and constrictivity, macroscopic material parameters such as diaphragm diameter and length, as well as process parameters like internal electrode pressure or the electrolyte viscosity and specific resistivity. Comprising sets of design parameters to dimensionless groups, concrete design guidelines as well as the introduction of a three-dimensional improvement space concept are proposed. The novel design space concept allows the improvement of each possible diaphragm-based measurement set-up, by considering the simultaneous, dimensionless interaction of all relevant design parameters

Модернизация конструкции и технологии изготовления герметичного кожуха

Цель работы состоит в усовершенствовании конструкции детали герметичный "кожух" с целью снижения вероятности отклонений его качественных показателей при испытаниях и условиях космических полетов (высокие температура и давление, низкие температуры космического пространства, вибрационные нагрузки на этапе выведения, радиационное воздействие, глубокий вакуум, микрочастицы и т. д.) и иметь низкую удельную массу.The purpose of the work is to improve the design of a hermetically sealed "casing" part in order to reduce the likelihood of deviations in its quality indicators during tests and conditions of space flights (high temperature and pressure, low temperatures of outer space, vibration loads during the launching phase, radiation exposure, deep vacuum, microparticles, etc.) and have a low specific gravity

Realistic 3D printed imaging tumor phantoms for validation of image processing algorithms

Medical imaging phantoms are widely used for validation and verification of imaging systems and algorithms in surgical guidance and radiation oncology procedures. Especially, for the performance evaluation of new algorithms in the field of medical imaging, manufactured phantoms need to replicate specific properties of the human body, e.g., tissue morphology and radiological properties. Additive manufacturing (AM) technology provides an inexpensive opportunity for accurate anatomical replication with customization capabilities. In this study, we proposed a simple and cheap protocol to manufacture realistic tumor phantoms based on the filament 3D printing technology. Tumor phantoms with both homogenous and heterogenous radiodensity were fabricated. The radiodensity similarity between the printed tumor models and real tumor data from CT images of lung cancer patients was evaluated. Additionally, it was investigated whether a heterogeneity in the 3D printed tumor phantoms as observed in the tumor patient data had an influence on the validation of image registration algorithms. A density range between -217 to 226 HUs was achieved for 3D printed phantoms; this range of radiation attenuation is also observed in the human lung tumor tissue. The resulted HU range could serve as a lookup-table for researchers and phantom manufactures to create realistic CT tumor phantoms with the desired range of radiodensities. The 3D printed tumor phantoms also precisely replicated real lung tumor patient data regarding morphology and could also include life-like heterogeneity of the radiodensity inside the tumor models. An influence of the heterogeneity on accuracy and robustness of the image registration algorithms was not found

The nuclear envelope protein Nesprin-2 has roles in cell proliferation and differentiation during wound healing

Nesprin-2, a type II transmembrane protein of the nuclear envelope, is a component of the LINC complex that connects the nuclear lamina with the actin cytoskeleton. To elucidate its physiological role we studied wound healing in Nesprin-2 Giant deficient mice and found that a loss of the protein affected wound healing particularly at later stages during fibroblast differentiation and keratinocyte proliferation leading to delayed wound closure. We identified altered expression and localization of transcription factors as one of the underlying mechanisms. Furthermore, the actin cytoskeleton which surrounds the nucleus was altered and keratinocyte migration was slowed down and focal adhesion formation enhanced. We also uncovered a new activity of Nesprin-2. When we probed for an interaction of Nesprin-2 Giant with chromatin we observed in ChIP Seq experiments an association of the protein with heterochromatic and centromeric DNA. Through this activity Nesprin-2 can affect the nuclear landscape and gene regulation. Our findings suggest functions for Nesprin-2 at the nuclear envelope (NE) in gene regulation and in regulation of the actin cytoskeleton which impact on wound healing