Ambulante Methode zur Charakterisierung des Glucosemetabolismus unter Verwendung von getrocknetem Blut und stabiler, nicht radioakti-ver Isotopenmarkierung : Dried blood spots (DBS-GLUC)

Ein wichtiges Ziel in der Diabetesforschung besteht darin, Wege zu finden, den Glucosestoff-wechsel von Patienten möglichst nicht invasiv und ohne großen Aufwand möglichst präzise darstellen zu können, um so eine drohende Stoffwechselentgleisung möglichst früh zu erken-nen, oder aber um gezielte Angriffspunkte für die Therapie eines bereits manifesten Diabetes zu erhalten. Ziel der vorliegenden Arbeit war es, durch orale Gabe von nicht radioaktiv mar-kierter Glucose (Isotopolog [U13C6]) und seriellen Messungen der Metaboliten mittels Mas-senspektroskopie die Ermittlung des Flusses der Glucose bzw. der Metaboliten mittels eines „Point of Care (POC) Ansatzes erfassbar zu machen. Hierzu verwendeten wir ein standardi-siertes Protokoll zur Extraktion und nachfolgenden massenspektrometrischen Analytik von Isotopenverteilungsmustern der Ziel-Metaboliten Glucose und Laktat. Um aus den Isotopen-verteilungsmustern quantitative Cori-Zyklus Flüsse zu gewinnen, modellierten wir diesen Zyk-lus mit Differentialgleichungssystemen und validierten ihn mittels Messungen über acht Stun-den nach Verabreichung von 2 g isotopenmarkierter Glukose an gesunden Probanden und Patienten mit Diabetes mellitus. Im Resultat konnte ein Verfahren entwickelt werden, welches den Fluss der aufgenommenen Glucose beziehungsweise ihrer Metaboliten erfassen kann. Um in dieser Vielzahl der massenspektrometrisch erfassten Datenmesspunkte ein Muster ähnlicher Verläufe beziehungsweise Ballung von Messpunkten unter bestimmten Bedingun-gen zu explorieren, wurde darüber hinaus eine Clusteranalyse durchgeführt. Hierdurch konn-ten zwei Cluster identifiziert werden: In Cluster eins zeigten die Patienten höhere Glucose-konzentrationen und Glucoseproduktionen als in Cluster zwei. Cluster eins bestand fast voll-ständig aus Diabetikern; Cluster zwei aus Nicht-Diabetikern. Lediglich ein männlicher Nicht-Diabetiker zeigte ebenfalls eine erhöhte Glucoseproduktion und wurde Cluster eins zugeord-net. Dieser entwickelte zwei Jahre nach Versuchsdurchführung einen gestörten Glucoseme-tabolismus (= Prädiabetes). Es konnte also exemplarisch anhand eines Patienten gezeigt werden, dass anhand des Clusterings, der in der Untersuchung aus Glucoseproduktion und Glucosekonzentration modellierten Flüsse der Glucose, eine gestörte Glucosetoleranz früh-zeitig noch vor klinischer Manifestation erfasst werden kann. Wir behaupten daher, dass die Sensitivität der frühen Diabetes-Diagnostik in Zukunft durch die in der vorliegenden Arbeit vorgestellte Methodik gesteigert werden könnte.An important goal in diabetes research is finding ways to represent the glucose metabolism of patients as non-invasively as possible and with low expenditure, recognizing an impending metabolic imbalance easily or obtaining targeted points of attack for the therapy of an already manifest diabetes. The work´s aim was to determine the flow of glucose or metabolites using a point of care (POC) approach through oral administration of non-radioactively labeled glucose (Isotopolog [U13C6]) and serial measurements of the metabolites using mass spectroscopy to make tangible. Therefore, we used a standardized protocol for the extraction and mass spectrometric analysis of isotope distribution patterns of the target metabolites glucose and lactate. In order to obtain quantitative Cori cycle flows from the isotope distribution patterns, we modeled this cycle with systems of differential equations and validated it by means of measurements over eight hours after administration of 2 g of isotope-labeled glucose to individual patients and patients with diabetes mellitus. Consequently, a method could be developed which can record the flow of glucose ingested or its metabolites. In order to expose a pattern of similar courses or clustering of measuring points under certain conditions in this recorded mass spectrometric data measuring point, a cluster analysis was implemented. As a result, two clusters could be identified: Cluster one shows the patients with higher glucose concentrations and glucose productions than in cluster two. Cluster one quickly consisted entirely of diabetics; cluster two from non-diabetics. Only one male non-diabetic also showed glucose production and cluster one was increased. Two years after the experiment, this patient developed a disturbed glucose metabolism (= prediabetes). Using a patient could be exemplified that a disturbed glucose tolerance can be detected early before clinical manifestation by clustering modeled flows. Therefore, we claim that the sensitivity of early diabetes diagnosis could be increased in the future by the method presented in the present work

Empirische Sozialforschung: von der Schwierigkeit die Wahrheit zu sagen: illustriert mit Beispielen aus der Transformationsforschung und der Stadtsoziologie (Halle/ Saale)

In seinem Beitrag befasst sich der Autor im Kontext der empirischen Sozialforschung mit dem Aspekt wahrer Aussagen seitens der Wissenschaftler und Medien auf der Basis erhobenen Datenmaterials. In einem ersten Schritt wird die wissenschaftstheoretische Debatte um die Schlüsselbegriffe der Wahrheit bzw. Wirklichkeit und ihrer empirischen Überprüfbarkeit skizziert. Daran schließen persönliche Erfahrungen von Dateninterpretationen in den Arbeitsgebieten der Transformationsforschung, also der Wiedervereinigung, und der Stadtsoziologie an. Sie umfassen: (1) Arbeitslosenstatistiken, (2) Statistiken des Bundesamtes, (3) politische Presseerklärungen, (4) Städte-Ranking, (5) Aussagen in den Printmedien sowie (6) insbesondere die Bürgerumfragen in Halle, die das Institut für Soziologie in Kooperation mit der Stadt seit 1993 durchführt. (ICG2

Planar Zeolite Film-Based Potentiometric Gas Sensors Manufactured by a Combined Thick-Film and Electroplating Technique

Zeolites are promising materials in the field of gas sensors. In this technology-oriented paper, a planar setup for potentiometric hydrocarbon and hydrogen gas sensors using zeolites as ionic sodium conductors is presented, in which the Pt-loaded Na-ZSM-5 zeolite is applied using a thick-film technique between two interdigitated gold electrodes and one of them is selectively covered for the first time by an electroplated chromium oxide film. The influence of the sensor temperature, the type of hydrocarbons, the zeolite film thickness, and the chromium oxide film thickness is investigated. The influence of the zeolite on the sensor response is briefly discussed in the light of studies dealing with zeolites as selectivity-enhancing cover layers

Platform for a Hydrocarbon Exhaust Gas Sensor Utilizing a Pumping Cell and a Conductometric Sensor

Very often, high-temperature operated gas sensors are cross-sensitive to oxygen and/or they cannot be operated in oxygen-deficient (rich) atmospheres. For instance, some metal oxides like Ga2O3 or doped SrTiO3 are excellent materials for conductometric hydrocarbon detection in the rough atmosphere of automotive exhausts, but have to be operated preferably at a constant oxygen concentration. We propose a modular sensor platform that combines a conductometric two-sensor-setup with an electrochemical pumping cell made of YSZ to establish a constant oxygen concentration in the ambient of the conductometric sensor film. In this paper, the platform is introduced, the two-sensor-setup is integrated into this new design, and sensing performance is characterized. Such a platform can be used for other sensor principles as well

First Computation of Parasitic Fields in LHC Dipole Magnet Interconnects

The Large Hadron Collider (LHC), now under construction at CERN, will rely on about 1600 main superconducting dipole and quadrupole magnets and over 7400 superconducting corrector magnets distributed around the eight sectors of the machine. Each magnet type is powered by dedicated superconducting busbars running along the sectors and mounted on the iron yokes of the main dipole and quadruple magnets. In the numerous magnet interconnects, the busbars are not magnetically shielded from the beam pipes and produce parasitic fields that can affect beam optics. We review the 3-D models that have been developed with ROXIE to compute the parasitic fields and we discuss their potential impacts on machine performance

Metal-Organic Frameworks for Sensing Applications in the Gas Phase

Several metal-organic framework (MOF) materials were under investigated to test their applicability as sensor materials for impedimetric gas sensors. The materials were tested in a temperature range of 120 °C - 240 °C with varying concentrations of O2, CO2, C3H8, NO, H2, ethanol and methanol in the gas atmosphere and under different test gas humidity conditions. Different sensor configurations were studied in a frequency range of 1 Hz -1 MHz and time-continuous measurements were performed at 1 Hz. The materials did not show any impedance response to O2, CO2, C3H8, NO, or H2 in the gas atmospheres, although for some materials a significant impedance decrease was induced by a change of the ethanol or methanol concentration in the gas phase. Moreover, pronounced promising and reversible changes in the electric properties of a special MOF material were monitored under varying humidity, with a linear response curve at 120 °C. Further investigations were carried out with differently doped MOF materials of this class, to evaluate the influence of special dopants on the sensor effect

Models and experimental results from the wide aperture Nb-Ti magnets for the LHC upgrade

MQXC is a Nb-Ti quadrupole designed to meet the accelerator quality requirements needed for the phase-1 LHC upgrade, now superseded by the high luminosity upgrade foreseen in 2021. The 2-m-long model magnet was tested at room temperature and 1.9 K. The technology developed for this magnet is relevant for other magnets currently under development for the high-luminosity upgrade, namely D1 (at KEK) and the large aperture twin quadrupole Q4 (at CEA). In this paper we present MQXC test results, some of the specialized heat extraction features, spot heaters, temperature sensor mounting and voltage tap development for the special open cable insulation. We look at some problem solving with noisy signals, give an overview of electrical testing, look at how we calculate the coil resistance during at quench and show that the heaters are not working We describe the quench signals and its timing, the development of the quench heaters and give an explanation of an Excel quench calculation and its comparison including the good agreement with the MQXC test results. We propose an improvement to the magnet circuit design to reduce voltage to ground values by factor 2. The program is then used to predict quench Hot-Spot and Voltages values for the D1 dipole and the Q4 quadrupole.Comment: 8 pages, Contribution to WAMSDO 2013: Workshop on Accelerator Magnet, Superconductor, Design and Optimization; 15 - 16 Jan 2013, CERN, Geneva, Switzerlan

Technikgenese in partizipativen Prozessen – Perspektiven einer neuen Forschungs- und Technologiepolitik

Weyer J, Schmidt J, Kirchner U. Technikgenese in partizipativen Prozessen – Perspektiven einer neuen Forschungs- und Technologiepolitik . In: Sahner H, Schwendtner S, eds. Gesellschaften im Umbruch. 27. Kongreß der Deutschen Gesellschaft für Soziologie in Halle an der Saale. Kongreßband II: Berichte aus den Sektionen und Arbeitsgruppen. Opladen: Westdeutscher Verlag; 1995: 629-633