Metabonomics and biomarker discovery: LC-MS metabolic profiling and constant neutral loss scanning combined with multivariate data analysis for mercapturic acid analysis

In the field of metabonomics, 1H NMR and full scan mass spectrometry methods have usually been combined with principal component analysis (PCA) and partial least squares discriminant analysis (PLS-DA) to detect patterns in biofluids that correspond to specific effects, usually a toxic site effect of a compound. Confounders together with great interindividual variation complicate such analysis in humans, and therefore, metabonomic data are almost restricted to animals. In our study, a constant neutral loss (CNL) scan on a linear ion trap demonstrated increased sensitivity and specificity compared to a full scan approach and was performed to detect mercapturic acids (MA), a class of effect markers. The method was applied to human volunteers administered 50 and 500 mg of acetaminophen (AAP), a model compound known to form MAs. Using a new algorithm to prepare the CNL data for chemometrics, discrimination of control and postdose samples could be performed using PCA and PLS-DA. The loadings plots clearly revealed AAP-MA as a marker, even at low-dose levels. Orthogonal signal correction (OSC) was carried out to investigate background information that is not due to exposure. Surprisingly, the OSC data provided a classification of male and female subjects showing the performance of the new approach.     

Hochwasserschutz im Land Bremen – Anpassung an prognostizierte Klimaänderungen

Im Beitrag wird auf Besonderheiten bei der Umsetzung des Generalplans Küstenschutz Niedersachsen/Bremen im Land Bremen eingegangen. Im ersten Teil werden die Grundlagen und Ergebnisse des Generalplans sowie die administrative Aufstellung des Landes Bremen zur Anpassung des Hochwasserschutzes beschrieben. Das Instrument der Kostenvergleichsrechnung wird vorgestellt, welches in Bremen bereits im frühen Projektstadium zur Bewertung der Vorzugslösungen eingesetzt wird. Ein wichtiger Aspekt bei der Umsetzung des Generalplans sind die technischen Anforderungen, die sich aus den bestehenden Hochwasserschutzanlagen ergeben. Weiterhin müssen im Land Bremen die Maßnahmen zum Hochwasserschutz im Wesentlichen unter Berücksichtigung der bestehenden konstruktiv geprägten Ufer (Spundwände und Kaianlagen) umgesetzt werden. Dabei sind spezielle Anforderungen hinsichtlich der aktuellen und zukünftigen Nutzung insbesondere in den Hafenrevieren zu berücksichtigen. Beispielhaft werden begleitende Projekte der INROS LACKNER AG vorgestellt. Flood protection in the Federal State and the city of Bremen by adjustment of climate changes. The present article describes how the Federal State and the Free Hanseatic City of Bremen adapts its flood protection with respect to climate changes and global sea level rise. Design basics are compiled in the “Generalplan Küstenschutz Niedersachsen/Bremen” (General Plan for Coastal Protection – Lower Saxony/Bremen). Main results of the general plan will be described and administrative aspects of the adaptation of the flood protection elements in Bremen will be lined out. Special technical requirements as the consideration of existing walls and dikes will be described. Also requirements from harbour operation, recreational use and urban architecture have to be considered as the Bremen port partly undergoes a rapid change in this regard. The instrument of cost analysis will be introduced which is utilised in Bremen at an early stage of planning in order to develop cost effective measures of public founded projects. Mentioned topics will be described based on projects carried out by INROS LACKNER AG.     

Challenges and constraints of using oxygen cathodes in microbial fuel cells

The performance of oxygen reduction catalysts (platinum, pyrolyzed iron(ll) phthalocyanine (pyr-FePc) and cobalt tetramethoxyphenylporphyrin (pyr-CoTMPP)) is discussed in light of their application in microbial fuel cells. It is demonstrated that the physical and chemical environment in microbial fuel cells severely affects the thermodynamics and the kinetics of the electrocatalytic oxygen reduction. The neutral pH in combination with low buffer capacities and low ionic concentrations strongly affect the cathode performance and limit the fuel cell power output. Thus, the limiting current density in galvanodyanamic polarization experiments decreases from 1.5 mA cm(-2) to 0.6 mA cm(-2) (pH 3.3, E(cathode) = 0 V) when the buffer concentration is decreased from 500 to 50 mM. The cathode limitations are superposed by the increasing internal resistance of the MFC that substantially contributes to the decrease of power output. For example, the maximum power output of a model MFC decreased by 35%, from 2.3 to 1.5 mW, whereas the difference between the electrode potentials (deltaE = E(anode) - E(cathode)) decreased only by 10%. The increase of the catalyst load of pyr-FePc from 0.25 to 2 mg cm(-2) increased the cathodic current density from 0.4 to 0.97 mA cm(-2) (pH 7, 50 mM phosphate buffer). The increase of the load of such inexpensive catalyst thus represents a suitable means to improve the cathode performance in microbial fuel cells. Due to the low concentration of protons in MFCs in comparison to relatively high alkali cation levels (ratio C(Na+,K+)/C(H+) = 5 x E5 in pH 7, 50 mM phosphate buffer) the transfer of alkali ions through the proton exchange membrane plays a major role in the charge-balancing ion flux from the anodic into the cathodic compartment. This leads to the formation of pH gradients between the anode and the cathode compartment.     

Drying quality of rubberwood: an industrial perspective

In this study, the kiln drying yield of 30 mm Rubberwood (Hevea brasiliensis) used for the furniture manufacturing industry in South East Asia was evaluated. The results showed that the average yield loss was 10%, and end-checks, splits and warping were the most common drying defects. It was found that sawn timber from older trees (>?21 years) were less prone to drying defects, and the use of stress relieving treatments significantly reduced the incidence of drying defects.     

Zur Zahnentwicklung und Alterssch?tzung beim Sikawild (Sika nippon)

Zusammenfassung Die Untersuchung der Gebißentwicklung beim Sikawild erbrachte Übereinstimmung zu der des Damwildes.Infolge der nur unwesentlich voneinander abweichenden Länge der Praemolaren- und Molarenreihe bei Sikawild und Damwild wird es als vertretbar angesehen, für die Altersschätzung des Sikawildes nach der Backenzahnabnutzung die für das Damwild festgelegte Abnutzung zu unterstellen.Ersatzdentinschichten bzw. Zementzonen konnten in der Krone des erste Schneidezahnes, an der Wurzel des ersten Schneidezahnes und im Wurzelbogen des ersten Molars nachgewiesen werden. Für die praktische Altersschätzung wird die Zementzonenbestimmung im Wurzelbogen des ersten Molars empfohlen. Die Zahl der Zementzonen entspricht dem zu schätzenden Alter in Jahren.

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Summary The investigation of tooth-development in sika-deer disclosed it to be corresponding to the one in fallow-deer.Because of the very small differences in molar and premolar length in these two species, it is considered to be justified to use the pattern of tooth-wear in fallow-deer for the aging of sika.Secondary dentin respectively tooth cementum were found to exist in the crown and at the root of the first incisor as well as inbetween the roots of the first molar.The count of layers in the cementum of the first molar is recommended for aging.

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Résumé L'analyse du développement de la dentition chez le Cerf Sika révèle une correspondance avec celui du Daim.En raison de la longueur à peine différente de la rangée des molaires chez ces deux espèces, il semble raisonnable, pour l'estimation de l'âge du Cerf Sika, de se baser sur le degré d'usure des molaires tel qu'il a été constaté chez le Daim.Des couches de dentine de remplacement ou des cernes de cément ont pu être mis en évidence dans la couronne de l'I₁, dans la racine de l'I₁ et dans celle de la M₁. Dans la pratique il est conseillé de faire plutôt l'examen des cernes de cément de la M₁. Le nombre de cernes de cément correspond à l'âge à estimer en années

     

Buchbesprechungen

Ohne Zusammenfassung     

A Magnetic Resonance Investigation of the Process of Corundum Formation Starting from Sol–Gel Precursors

²⁷Al–MAS (magic angle spinning)–NMR and Fe³⁺ EPR measurements have been performed to follow the local process of corundum formation starting from xerogel on the Al³⁺ and Fe³⁺ sites yielding complementary information. Different heat treatments have been applied to the samples: an isochronous procedure and thermoanalytical measurements stopped by quenching. Despite the different mechanisms of the phase transitions deduced, both seeding and Fe³⁺ doping under the conditions of isochronous procedure favor the formation of α-Al₂O₃ at remarkably low temperatures. The first observed temperature of corundum formation following the isochronous procedure with iron-doped samples is as low as 750°C. The transition alumina, which could be clearly evidenced, is the γ-Al₂O₃ phase (four- and six-fold Al coordination). In undoped or unseeded samples, intermediate Fe species could be detected by ESR and evidence for θ-Al₂O₃ was obtained from ²⁷Al–NMR spectroscopy.     

Towards FE-simulation based production planning and development

To remain competitive in times of unstable markets and shrinking sales, automotive manufacturers are under pressure to decrease the product development time. Especially, the time for planning of production steps and processes is strictly limited. The numerical simulation of production processes can help to get insight into the parts’ behavior and properties and to evaluate the feasibility of the production steps. In this paper the role and application of the welding simulation for the production planning is discussed. The computed welding distortion can be taken into account before the forming tools are constructed and the first sheet parts are produced. Hence, many problems occurring during the assembly of welded parts can be identified and avoided and the number of prototypes can be reduced.     

Gel-combustion synthesis of nanocrystalline spinel catalysts for VOCs elimination

Gel-combustion synthesis (GCS) in self-sustaining mode was used for preparation of mixed oxide with spinel structure AB₂O₄ (where A = Co, Cu and B = Cr, Co). To support these mixed oxides on CeO₂ and ZrO₂ powders, the GCS technique in self-propagating mode was developed. The synthesized materials were characterized by IR-spectroscopy, X-ray diffraction and transmission electron microscopy. The GCS preparation leads to the formation of nanocrystalline, single-phase spinel catalysts, which showed high activity in VOCs (hexane) elimination. The best catalytic performance was obtained over copper cobaltite catalyst prepared by GCS from glycerin-chelated precursor.     

A SQUID-Based Nondestructive Evaluation System for Testing Wires of Arbitrary Length

The high field sensitivity of superconducting quantum interference devices (SQUIDs), especially at low frequencies, makes them ideally suited for applications in nondestructive evaluation. For testing of conducting wires, such as aluminum bond wire, we developed a special cryostat, which allows for pulling a wire of arbitrary length (which is kept at room temperature) through a niobium flux transformer connected to a niobium dc SQUID. The wire is excited by either passing an alternating current through it, or by exciting eddy-currents in the wire. The cryostat is made from a stainless steel inner vessel; the outer tube is from fiberglass. The gradiometric pickup loops are wound on a German-silver tube. As the wire under test is at room temperature, thermal noise produced by the wire is limiting the sensitivity of the system, rather than thermal noise produced by the stainless steel dewar.