Simultaneous Quantification and Visualization of Titanium Dioxide Nanomaterial Uptake at the Single Cell Level in an In Vitro Model of the Human Small Intestine

International audienceUseful properties render titanium dioxide nanomaterials (NMs) to be one of the most commonly used NMs worldwide. TiO2 powder is used as food additives (E171), which may contain up to 36% nanoparticles. Consequently, humans could be exposed to comparatively high amounts of NMs that may induce adverse effects of chronic exposure conditions. Visualization and quantification of cellular NM uptake as well as their interactions with biomolecules within cells are key issues regarding risk assessment. Advanced quantitative imaging tools for NM detection within biological environments are therefore required. A combination of the label-free spatially resolved dosimetric tools, microresolved particle induced X-ray emission and Rutherford backscattering, together with high resolution imaging techniques, such as time-of-flight secondary ion mass spectrometry and transmission electron microscopy, are applied to visualize the cellular translocation pattern of TiO2 NMs and to quantify the NM-load, cellular major, and trace elements in differentiated Caco-2 cells as a function of their surface properties at the single cell level. Internalized NMs are not only able to impair the cellular homeostasis by themselves, but also to induce an intracellular redistribution of metabolically relevant elements such as phosphorus, sulfur, iron, and copper

FASA - Fire Airborne Spectral Analysis of Natural Disasters

At present the authors are developing the system FASA, an airborne combination of a Fourier Transform Spectrometer and an imaging system. The aim is to provide a system that is usable to investigate and monitor emissions from natural disasters such as wild fires and from volcanoes. Besides temperatures and (burned) areas FASA will also provide concentration profiles of the gaseous combustion products. These data are needed to improve the knowledge of the effects of such emissions on the global ecosystem. The paper presents a description of the instrumentation, the data evaluation procedure and shows first results of retrieval calculations based on simulated spectra

Finishing the euchromatic sequence of the human genome

The sequence of the human genome encodes the genetic instructions for human physiology, as well as rich information about human evolution. In 2001, the International Human Genome Sequencing Consortium reported a draft sequence of the euchromatic portion of the human genome. Since then, the international collaboration has worked to convert this draft into a genome sequence with high accuracy and nearly complete coverage. Here, we report the result of this finishing process. The current genome sequence (Build 35) contains 2.85 billion nucleotides interrupted by only 341 gaps. It covers ∼99% of the euchromatic genome and is accurate to an error rate of ∼1 event per 100,000 bases. Many of the remaining euchromatic gaps are associated with segmental duplications and will require focused work with new methods. The near-complete sequence, the first for a vertebrate, greatly improves the precision of biological analyses of the human genome including studies of gene number, birth and death. Notably, the human enome seems to encode only 20,000-25,000 protein-coding genes. The genome sequence reported here should serve as a firm foundation for biomedical research in the decades ahead

Performance Tests of a Digital Channel Matrix for Baseband Wavefront Generation Apllicable to CRPA Receivers

Digital baseband wavefront generation offers high flexibility and allows the simulation and testing of relative large multi-element antenna systems compared to analogue solutions at RF. A digital matrix processor for baseband wavefront generation was developed by DLR, which is combined with a multi-channel GNSS signal simulator. This paper presents performance test results of the digital matrix, in particular for the key feature of wavefront generation, its capability to produce defined carrier phase shifts by complex weighting of the I/Q baseband signals originating from the GNSS simulator before the signals are up-converted to RF

First Results of Baseband Wavefront Generation with a Digital Channel Matrix for Testing of CRPA

Digital baseband wavefront generation offers high flexibility and allows the simulation and testing of relative large multi-element antenna systems compared to analogue solutions at RF. A digital matrix processor for baseband wavefront generation was developed by DLR, which is combined with a multi-channel GNSS signal simulator. This paper presents performance test results of the digital matrix, in particular for the key feature of wavefront generation, its capability to produce defined carrier phase shifts by complex weighting of the I/Q baseband signals originating from the GNSS simulator before the signals are up-converted to RF

DESIS CMOS Detector Verification

Calibration and verification of the DESIS (DLR Earth Sensing Imaging Spectrometer) detector for the VIS/NIR (VNIR) spectral range. DESIS is a hyperspectral sensor for the international space station, developed by the German Aerospace Center (DLR) and operated by Teledyne Brown Engineering (TBE). TBE also provide the MUSES platform. The primary goal of DESIS is to measure and analyze quantitative diagnostic parameters describing key processes on the Earth surface. The main components of the sensor, the detector and the focal plane, were examined and verified. This allows predictions about the future data quality. The verification and validation of components and the entire system is an important and challenging task

MERTIS - the design of a highly integrated IR imaging spectrometer

A belief that Mercury carries unique clues to the origin and evolution of the Solar System has driven the interest for detailed studies of the innermost planet. Here surface mineralogy requires information of the thermal inertia asking for observations by space borne instruments in the near IR and the thermal IR domain. With a background of several instrument developments in the past the German Aerospace Center in Berlin proposed for ESA’s deep space mission BepiColombo an imaging spectrometer which meets the challenges of limited technical resources and a very special operational environment. An 80-channel push broom-type spectrometer has been drafted and it s development has been started under the name MERTIS (MERcury Thermal Infrared Spectrometer). It is based on modern European un-cooled micro-bolometer technology and all-reflective optics design. The operation concept principle is characterised by intermediate scanning of the planet, free space and black bodies as calibration targets. A miniaturised radiometer is included for low level temperature measurements. Altogether the system shall fit into a CD-package sized cube and weigh less than 3 kg. The paper will present the instrument architecture of MERTIS, its design status and results of laboratory investigations with the first components being built

sCMOS detector for imaging VNIR spectrometry

The Optical Information Systems at the Robotics and Mechatronics Center of the German Aerospace Center (DLR) has more than 30 years experience with high-resolution imaging technology. The paper shows the institut’s scientific results of leading edge instrument and focal plane designs for EnMAP VIS/NIR spectrograph. The EnMAP project includes the technological design of the hyperspectral spaceborne instrument and the algorithms development of the classification. Kayser-Threde GmbH has the lead of the space segment and the Geo Forschungs Zentrum Potsdam is the Principal Investigator of EnMAP. The paper gives an overview over the challenging FPA design and the achieved performances including the verification program at DLR, new control possibilities for sCMOS detectors in global shutter mode and key parameters like PRNU, DSNU, MTF, SNR, Linearity, Spectral Response, Quantum Efficiency, Flatness and Radiation Tolerance will be discussed in detail

Verification and calibration of the DESIS detector

This paper focuses on the calibration and verification of the DESIS (DLR Earth Sensing Imaging Spectrometer) detector for the VIS/NIR (VNIR) spectral range. DESIS is a hyperspectral Instrument for the international space station, developed from the German Aerospace Center (DLR) and operate by Teledyne Brown Engineering (TBE). TBE provides the MUSES platform, on which the DESIS instrument will be mounted. The primary goal of DESIS is to measure and analyse quantitative diagnostic parameters describing key processes on the Earth surface. The main components of the sensor, the detector and the focal plane, were examined and verified. This allows predictions about the future data quality. The verification and validation of components and the entire system is an important and challenging task. The verification of the detectors is necessary to describe the characteristics of the detector according to predetermined specifications. The quantities to be examined are e.g. the quantum efficiency, the linearity of the detector, the pixel response non-uniformity (PRNU) and the dark current noise. For this purpose, specially calibrated integrated spheres are used that allow traceability of the measured data. With these information, the future performance of the sensor can be estimated using simulations