Disrupted neural correlates of anesthesia and sleep reveal early circuit dysfunctions in Alzheimer models.

Dysregulated homeostasis of neural activity has been hypothesized to drive Alzheimer's disease (AD) pathogenesis. AD begins with a decades-long presymptomatic phase, but whether homeostatic mechanisms already begin failing during this silent phase is unknown. We show that before the onset of memory decline and sleep disturbances, familial AD (fAD) model mice display no deficits in CA1 mean firing rate (MFR) during active wakefulness.

Synchrotron radiation micro X-ray fluorescence spectroscopy of thin structures in bone samples: comparison of confocal and color X-ray camera setups.

In the quest for finding the ideal synchrotron-radiation-induced imaging method for the investigation of trace element distributions in human bone samples, experiments were performed using both a scanning confocal synchrotron radiation micro X-ray fluorescence (SR-µXRF) (FLUO beamline at ANKA) setup and a full-field color X-ray camera (BAMline at BESSY-II) setup. As zinc is a trace element of special interest in bone, the setups were optimized for its detection. The setups were compared with respect to count rate, required measurement time and spatial resolution.

Micro X-ray Fluorescence Imaging in a Tabletop Full Field-X-ray Fluorescence Instrument and in a Full Field-Particle Induced X-ray Emission End Station.

A full field-X-ray camera (FF-XRC) was developed for performing the simultaneous mapping of chemical elements with a high lateral resolution. The device is based on a conventional CCD detector coupled to a straight shaped polycapillary. Samples are illuminated at once with a broad primary beam that can consist of X-rays or charged particles in two different analytical setups.

High spectral and spatial resolution X-ray transmission radiography and tomography using a Color X-ray Camera.

High resolution X-ray radiography and computed tomography are excellent techniques for non-destructive characterization of an object under investigation at a spatial resolution in the micrometer range. However, as the image contrast depends on both chemical composition and material density, no chemical information is obtained from this data. Furthermore, lab-based measurements are affected by the polychromatic X-ray beam, which results in beam hardening effects.

Discovering vanished paints and naturally formed gold nanoparticles on 2800 years old phoenician ivories using SR-FF-microXRF with the color X-ray camera.

Phoenician ivory objects (8(th) century B.C., Syria) from the collections of the Badisches Landesmuseum, Karlsruhe, Germany, have been studied with full field X-ray fluorescence microimaging, using synchrotron radiation (SR-FF-microXRF).