The influence of estrogen deficiency on the structural and mechanical properties of rat cortical bone.

Background: Post-menopausal osteoporosis is a common health problem worldwide, most commonly caused by estrogen deficiency. Most of the information regarding the skeletal effects of this disease relates to trabecular bone, while cortical bone is less studied. The purpose of this study was to evaluate the influence of estrogen deficiency on the structure and mechanical properties of cortical bone.

Revealing Silver Nanoparticle Uptake by Macrophages Using SR-μXRF and LA-ICP-MS.

To better study the impact of nanoparticles on both and models, tissue distribution and cellular doses need to be described more closely. Here silver nanoparticles were visualized in alveolar macrophages by means of synchrotron radiation micro X-ray fluorescence spectroscopy (SR-μXRF) with high spatial resolution of 3 × 3 μm. For the spatial allocation of silver signals to cells and tissue structures, additional elemental labeling was carried out by staining with eosin, which binds to protein and can be detected as bromine signal with SR-μXRF.

A setup for synchrotron-radiation-induced total reflection X-ray fluorescence and X-ray absorption near-edge structure recently commissioned at BESSY II BAMline.

An automatic sample changer chamber for total reflection X-ray fluorescence (TXRF) and X-ray absorption near-edge structure (XANES) analysis in TXRF geometry was successfully set up at the BAMline at BESSY II. TXRF and TXRF-XANES are valuable tools for elemental determination and speciation, especially where sample amounts are limited (<1 mg) and concentrations are low (ng ml(-1) to µg ml(-1)). TXRF requires a well defined geometry regarding the reflecting surface of a sample carrier and the synchrotron beam.

Time- and spatial-resolved XAFS spectroscopy in a single shot: new analytical possibilities for in situ material characterization.

A new concept that comprises both time- and lateral-resolved X-ray absorption fine-structure information simultaneously in a single shot is presented. This uncomplicated set-up was tested at the BAMline at BESSY-II (Berlin, Germany). The primary broadband beam was generated by a double multilayer monochromator.

Metal elements in tissue with dental peri-implantitis: a pilot study.

Objectives: Dental peri-implantitis is characterized by a multifactorial etiology. The role of metal elements as an etiological factor for peri-implantitis is still unclear. The aim of this study was to investigate the incidence of metal elements in bone and mucosal tissues around dental Grade 4 CP titanium implants with signs of peri-implantitis in human patients.

Investigation of short-range structural order in Zr69.5Cu12Ni11Al7.5 and Zr41.5Ti41.5Ni17 glasses, using X-ray absorption spectroscopy and ab initio molecular dynamics simulations.

Short-range order has been investigated in Zr69.5Cu12Ni11Al7.5 and Zr41.

Thermally induced structural rearrangement of the Fe(II) coordination geometry in metallo-supramolecular polyelectrolytes.

Rigid rod-type metallo-supramolecular coordination polyelectrolytes with Fe(II) centres (Fe-MEPEs) are produced via the self-assembly of the ditopic ligand 1,4-bis(2,2':6',2''-terpyridine-4'-yl)benzene (tpy-ph-tpy) and Fe(II) acetate. Fe-MEPEs exhibit remarkable electrochromic properties; they change colour from blue to transparent when an electric potential is applied. This electrochemical process is generally reversible.

The structure of AuPd nanoalloys anchored on spherical polyelectrolyte brushes determined by X-ray absorption spectroscopy.

Well-defined and facetted bimetallic gold-palladium nanoalloys have been synthesized and anchored in spherical polyelectrolyte brushes (SPB) as composite particles (AuPd@SPB). These particles are better catalysts in aqueous phase than the pure metals. The atomistic arrangement of these nanoalloys has been analysed by extended X-ray absorption fine structure (EXAFS) spectroscopy at the Au-L3 and the Pd-K absorption edge.

Unremodeled endochondral bone is a major architectural component of the cortical bone of the rat (Rattus norvegicus).

The laboratory rat is one of the most frequently-used animal models for studying bone biology and skeletal diseases. Here we show that a substantial portion of the cortical bone of mature rats is primary endochondral bone, consisting of a disorganized arrangement of mineralized collagen fibers. We characterize the structure and mechanical properties of the cortical bone of the rat.

An in vitro pilot study of abutment stability during loading in new and fatigue-loaded conical dental implants using synchrotron-based radiography.

Purpose: The implant-abutment connection of a two-piece dental implant exhibits complex micromechanical behavior. A microgap is evident at the implant-abutment interface, even in the virgin state, and its width varies when an external mechanical load is applied.

Materials And Methods: This study used high-resolution synchrotron-based radiography in combination with hard x-ray phase-contrast mode to visualize this gap and estimate its size.

Beyond the Great Wall: gold of the silk roads and the first empire of the steppes.

Fingerprinting ancient gold work requires the use of nondestructive techniques with high spatial resolution (down to 25 μm) and good detection limits (micrograms per gram level). In this work experimental setups and protocols for synchrotron radiation induced X-ray fluorescence (SRXRF) at the BAMline of the Berlin electron storage ring company for synchrotron radiation (BESSY) in Berlin for the measurement of characteristic trace elements of gold are compared considering the difficulties, shown in previous works, connected to the quantification of Pt. The best experimental conditions and calculation methods were achieved by using an excitation energy of 11.

Imaging of articular cartilage--data matching using X-ray tomography, SEM, FIB slicing and conventional histology.

The study was aimed at demonstrating a true cellular resolution for articular cartilage using synchrotron radiation-based X-ray microcomputed tomography (SR-μCT) with a sample-specific optimization of the phase contrast. The generated tomographic data were later used to prepare a matching histological sample from the full volume specimen. We used highly coherent and monochromatic X-rays from a synchrotron source to image a tissue sample of bovine articular cartilage after deparaffinization.

Cr(VI)/Cr(III) and As(V)/As(III) ratio assessments in Jordanian spent oil shale produced by aerobic combustion and Anaerobic Pyrolysis.

With the increase in the awareness of the public in the environmental impact of oil shale utilization, it is of interest to reveal the mobility of potentially toxic trace elements in spent oil shale. Therefore, the Cr and As oxidation state in a representative Jordanian oil shale sample from the El-Lajjoun area were investigated upon different lab-scale furnace treatments. The anaerobic pyrolysis was performed in a retort flushed by nitrogen gas at temperatures in between 600 and 800 °C (pyrolytic oil shale, POS).

Compact pnCCD-based X-ray camera with high spatial and energy resolution: a color X-ray camera.

For many applications there is a requirement for nondestructive analytical investigation of the elemental distribution in a sample. With the improvement of X-ray optics and spectroscopic X-ray imagers, full field X-ray fluorescence (FF-XRF) methods are feasible. A new device for high-resolution X-ray imaging, an energy and spatial resolving X-ray camera, is presented.

Bond length contraction in gold nanoparticles.

The structure of nanoparticles typically differs from its bulk counterpart. Predominantly, the structures of gold nanoparticles have been under exceedingly intense discussion since the discovery of their high catalytic activity. We found an increasing bond length contraction with decreasing particle size for citrate-stabilized gold nanoparticles in aqueous solution as determined by in situ extended X-ray absorption fine structure (EXAFS) spectroscopy.

In vitro synchrotron-based radiography of micro-gap formation at the implant-abutment interface of two-piece dental implants.

Micro-gap formation at the implant-abutment interface of two-piece dental implants was investigated in vitro using high-resolution radiography in combination with hard X-ray synchrotron radiation. Images were taken with the specimen under different mechanical loads of up to 100 N. The aim of this investigation was to prove the existence of micro-gaps for implants with conical connections as well as to study the mechanical behavior of the mating zone of conical implants during loading.

Real-time monitoring of copolymer stabilized growing gold nanoparticles.

A great challenge in the production of nanoparticles with defined sizes and properties is to control their growth in situ. We developed a dedicated combined small-angle X-ray scattering (SAXS) and X-ray absorption spectroscopy (XAS) setup to monitor nanoparticle formation in solution. The capabilities of simultaneously deriving particle sizes and oxidation states of atoms/ions are illustrated for the formation of spherical gold nanoparticles by the reduction of hydrogen tetrachloroaureate (HAuCl(4)).

Going beyond histology. Synchrotron micro-computed tomography as a methodology for biological tissue characterization: from tissue morphology to individual cells.

Current light microscopic methods such as serial sectioning, confocal microscopy or multiphoton microscopy are severely limited in their ability to analyse rather opaque biological structures in three dimensions, while electron optical methods offer either a good three-dimensional topographic visualization (scanning electron microscopy) or high-resolution imaging of very thin samples (transmission electron microscopy). However, sample preparation commonly results in a significant alteration and the destruction of the three-dimensional integrity of the specimen. Depending on the selected photon energy, the interaction between X-rays and biological matter provides semi-transparency of the specimen, allowing penetration of even large specimens.

Fresnel-propagated imaging for the study of human tooth dentin by partially coherent x-ray tomography.

Recent methods of phase imaging in x-ray tomography allow the visualization of features that are not resolved in conventional absorption microtomography. Of these, the relatively simple setup needed to produce Fresnel-propagated tomograms appears to be well suited to probe tooth-dentin where composition as well as microstructure vary in a graded manner. By adapting analytical propagation approximations we provide predictions of the form of the interference patterns in the 3D images, which we compare to numerical simulations as well as data obtained from measurements of water immersed samples.