A Microring Resonator Sensor for Sensitive Detection of 1,3,5-Trinitrotoluene (TNT)

A microring resonator sensor device for sensitive detection of the explosive 1,3,5-trinitrotoluene (TNT) is presented. It is based on the combination of a silicon microring resonator and tailored receptor molecules

Polyethylenimine-mediated gene delivery into human bone marrow mesenchymal stem cells from patients

Transplantation of mesenchymal stem cells (MSCs) derived from adult bone marrow has been proposed as a potential therapeutic approach for post-infarction left ventricular (LV) dysfunction. However, age-related functional decline of stem cells has restricted their clinical benefits after transplantation into the infarcted myocardium. The limitations imposed on patient cells could be addressed by genetic modification of stem cells. This study was designed to improve our understanding of genetic modification of human bone marrow derived mesenchymal stem cells (hMSCs) by polyethylenimine (PEI, branched with Mw 25 kD), one of non-viral vectors that show promise in stem cell genetic modification, in the context of cardiac regeneration for patients. We optimized the PEI-mediated reporter gene transfection into hMSCs, evaluated whether transfection efficiency is associated with gender or age of the cell donors, analysed the influence of cell cycle on transfection and investigated the transfer of therapeutic vascular endothelial growth factor gene (VEGF). hMSCs were isolated from patients with cardiovascular disease aged from 41 to 85 years. Optimization of gene delivery to hMSCs was carried out based on the particle size of the PEI/DNA complexes, N/P ratio of complexes, DNA dosage and cell viability. The highest efficiency with the cell viability near 60% was achieved at N/P ratio 2 and 6.0 μg DNA/cm 2. The average transfection efficiency for all tested samples, middle-age group (<65 years), old-age group (>65 years), female group and male group was 4.32%, 3.85%, 4.52%, 4.14% and 4.38%, respectively. The transfection efficiency did not show any correlation either with the age or the gender of the donors. Statistically, there were two subpopulations in the donors; and transfection efficiency in each subpopulation was linearly related to the cell percentage in S phase. No significant phenotypic differences were observed between these two subpopulations. Furthermore, PEI-mediated therapeutic gene VEGF transfer could significantly enhance the expression level.DFG/SFB/Transregio 37BMBF/0313191German Helmholtz AssociationDFG/0402710Ministry of Education/0312138 AMinistry of Economy (Mecklenburg-West Pommerania)/V220-630-08-TFMVF/S-035Marie Curie International Research Staff Exchange Scheme (IRSES, FP7-PEOPLE-2009-IRSES)Reference and Translation Center for Cardiac Stem Cell Therapy (RTC

Instabilities of molecule motion in a linear ac trap

Contains fulltext : 99136.pdf (publisher's version ) (Open Access

A Highly Sensitive Refractometric Sensor Based on Cascaded SiN Microring Resonators

We investigate a highly sensitive optical sensor based on two cascaded microring resonators exploiting the Vernier effect. The architecture consists of two microrings with a slight difference in their free spectral ranges. This allows the generation of the Vernier effect for achieving ultra-high sensitivities. The sensor chip was fabricated using a silicon nitride platform and characterized with isopropanol/ethanol mixtures. A sensitivity of 0.95 nm/% was found for isopropanol concentrations in ethanol ranging from 0% to 10%. Furthermore, a collection of measurements was carried out using aqueous sodium chloride (NaCl) in solutions of different concentrations, confirming a high sensitivity of 10.3 nm/% and a bulk refractive index sensitivity of 6,317 nm/RIU. A limit of detection of 3.16 ´ 10−6 RIU was determined. These preliminary results show the potential features of cascaded silicon nitride microring resonators for real-time and free-label monitoring of biomolecules for a broad range of applications

Preparing SCIAMACHY for the Mission Extension Phase

In 2010 ENVISAT enters its next mission extension phase when a manoeuvre transfers the platform from its nominal into a modified orbit. Therefore all SCIAMACHY measurements requiring an accurate pointing knowledge are affected. Therefore adjustments to SCIAMACHY’s on-board instrument configuration are necessary reflecting this orbit chance. Based on a detailed analysis simulating SCIAMACHY operations in the modified orbit until the end of 2013, the impacts on nadir, limb and solar and lunar measurements when orbiting the Earth at an altitude reduced by about 17 km was elaborated. By permanently modifying certain parameters stored on-board in SCIAMACHY’s memory these impacts can be compensated for. We present how the instrument configuration has to be adapted both in preparation of the actual orbit manoeuvre and for maintaining the performance over the mission extension phase

Chapter 3: The Instrument

The objective of the SCIAMACHY mission requires the instrument to be capable of determining concentrations of a large number of trace gas species over the full vertical extent of the atmosphere from the troposphere up to the mesosphere. In addition, aerosol properties as well as pressure and temperature shall be derived. Therefore SCIAMACHY was designed as a passive imaging spectrometer, comprising a scan mirror system, a telescope and a spectrometer, controlled by thermal and electronic subsystems. Scan mirrors, telescopes and spectrometer together form the optical assembly. The scan mechanisms permit steering the line-of-sight according to the required viewing geometries. Solar radiance and irradiance are dispersed by the spectrometer into 8 channels from the UV to the SWIR range. With signals gained from the calibration unit and the Polarisation Measurement Device, the spectral and radiometric calibration of the science channels can be maintained over the mission lifetime. Thermal stability is ensured via active and passive thermal control systems including the Radiant Cooler assembly. Those units which control the entire instrument and interface electrically with the ENVISAT platform are hosted by the Electronic Assembly. SCIAMACHY was developed in a combined effort of German, Dutch and Belgian space agencies, industry and scientists and ready for the ENVISAT launch in March 2002

Einsatz von Kunststoffen in Pkw : Literaturstudie

Ziel der vorliegenden Arbeit war es, eine möglichst umfassende Literaturstudie zu erstellen, die die Möglichkeiten und Probleme aufzeigt, die beim Einsatz von Kunststoffen in Kraftfahrzeugen auftreten können. Der Begriff "Kunststoffe" ist sehr weitreichend, so dass es zweckmäßig war, den Gesamtkomplex zu unterteilen. Die ausgewählte Gliederung richtet sich einerseits nach Werkstoffgruppen und andererseits nach übergeordneten Gesichtspunkten. Die Studie wurde daher in folgende, in sich geschlossene Abschnitte unterteilt. 1. Entwicklungen und Tendenzen beim Kunststoffeinsatz, 2. Rechtsvorschriften, 3. Eigenschaften und Anwendung von Kunststoffen, 4. Elastomere, 5. Textilien und Schaumstoffe, 6. Lacke und Beschichtungsstoffe, 7. Klebtechnik, 8. Alterung, 9. Brandverhalten/Brennverhalten, 10. Recycling. Insgesamt wurden annähernd eintausend Literaturstellen erfasst. Dabei handelt es sich vorwiegend um Publikationen, die zwischen 1980 und 1988 erschienen sind. Die an den Werkstoffen orientierte Gliederung ermöglicht einen guten Überblick über alle Verwendungsbereiche der jeweiligen Werkstoffgruppe beziehungsweise über zusammenfassende Problemstellungen. Damit unterscheidet sich diese Studie von anderen Literaturzusammenstellungen, die sich in der Regel auf spezielle Teile des Kraftfahrzeuges, wie beispielsweise Motor- oder Innenraum, beschränken. Allerdings werden in dieser Studie nur Probleme bezüglich des Einsatzes von Kunststoffen in Pkw behandelt. Die Studie kann vor allem solchen Institutionen beziehungsweise Personen dienen, für die werkstoffbezogene Übersichten wichtig sind, und die sie als Basis für die Einarbeitung in Einzelprobleme nutzen wollen. Eine Weiterführung der Arbeit auf diesem Gebiet ist wünschenswert. Dabei wäre insbesondere auf die Schwerpunkte 1. Schadensfrüherkennung "life monitoring", 2. Verbesserung der Stoßabsorption, 3. Alterungsverhalten von Klebeverbindungen, 4. On-line-Lackierung unter den Belangen des Umweltschutzes, 5. Reduzierung der Verwendung von Lösemitteln und 6. Reduzierung des Shreddermülls (Rückgewinnung sortenreiner Polymerwerkstoffe) einzugehen.The object of this research has been a comprehensive study of the relevant literature describing the possibilities and problems of the use of plastics in motor vehicles. "Plastics" is a term covering a wide range of materials. For that reason a classification was necessary. The classification system selected is based on groups of materials on the one hand and some major aspects on the other. For these reasons, the report has been subdivided into the following chapters: - Developments and trends in the use of plastic materials, - Legal regulations, - Elastomers, - Textiles and foamed materials, - Paints and coatings, automotive finishes, - Adhesive bonding technology, - Ageing, - Fire resistance/ burning behavior, - Recycling. Nearly one thousand references have been surveyed. Mostly they concern studies published between 1980 and 1988. The classification by types of materials provides a good overview of the range of application of individual groups of materials and also of the problems raised in this context. This distinguishes this study from other compilations of literature covering special parts of a car, e.g. engine and interior compartments. However, the report only deals with the problems that emerge when plastic materials are used in passenger cars. The study will be of particular use to the institutions or individuals for whom surveys of materials are of importance and necessary as a basis for familiarizing themselves with the problems involved. A continuation of the work in this area would be desirable, especially studies of such questions as the ones listed below: - Early recognition of damage/defects (life monitoring), - Improvement of impact absorption, - Ageing of adhesive joints, - On-line controlled finishes from the environmental viewpoint, - Reduction of the use of solvents, - Reduction of shredder waste (reusing of graded polymers