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An increase in the proportion of ambiguous base calls in HIV-1 pol population sequences during the course of infection has been demonstrated in different study populations, and sequence ambiguity thresholds to classify infections as recent or nonrecent have been suggested. The aim of our study was to evaluate sequence ambiguities as a candidate biomarker for use in an HIV-1 incidence assay using samples from antiretroviral treatment-naive seroconverters with known durations of infection (German HIV-1 Seroconverter Study). We used 2,203 HIV-1 pol population sequences derived from 1,334 seroconverters to assess the sequence ambiguity method (SAM). We then compared the serological incidence BED capture enzyme immunoassay (BED-CEIA) with the SAM for a subset of 723 samples from 495 seroconverters and evaluated a multianalyte algorithm that includes BED-CEIA results, SAM results, viral loads, and CD4 cell counts for 453 samples from 325 seroconverters. We observed a significant increase in the proportion of sequence ambiguities with the duration of infection. A sequence ambiguity threshold of 0.5% best identified recent infections with 76.7% accuracy. The mean duration of recency was determined to be 208 (95% confidence interval, 196 to 221) days. In the subset analysis, BED-CEIA achieved a significantly higher accuracy than the SAM (84.6 versus 75.5%, P < 0.001) and results were concordant for 64.2% (464/723) of the samples. Also, the multianalyte algorithm did not show better accuracy than the BED-CEIA (83.4 versus 84.3%, P = 0.786). In conclusion, the SAM and the multianalyte algorithm including SAM were inferior to the BED-CEIA, and the proportion of sequence ambiguities is therefore not a preferable biomarker for HIV-1 incidence testing.

BACKGROUND: The variety and limitations of current laboratory methods for estimating HIV-incidence has driven attempts to improve and standardize the performance of serological 'Tests for Recent HIV-Infections' (TRI). Primary and follow-up HIV-1 positive plasma samples from individuals with well-defined dates of infection collected as part of the German Seroconverter Cohort provided specimens highly suitable for use in comparing the performance of three TRIs: the AWARE™ BED™ EIA HIV-1 Incidence test (BED-CEIA), Genetic systems HIV-1/HIV-2 Plus O EIA antibody avidity-based assay (BioRad Avidity) and Sedia™ HIV-1 LAg Avidity EIA (LAg Avidity). METHODS: The evaluation panel included 180 specimens: 44 from antiretroviral (ARV)-naïve individuals with recently acquired HIV-infection (≤ 130 days; 25 B and 19 non-B subtypes) and 136 from long-term (>12 months) infected individuals [101 ARV-naïve subtype B, 16 non-B subtypes, 14 ARV-treated individuals, 5 slow progressors (SLP)]. RESULTS: For long-term infected, ARV-naïve individuals the false recent rates (FRR) of both the BioRad and LAg Avidity assays were 2% (2/101 for subtype B) and 6% (1/16 for subtype 'non-B'), while the FRR of the BED-CEIA was 7% (7/101 for subtype B) and 25% (4/16 for subtype 'non-B') (all p>0.05). Misclassification of ARV-treated individuals and SLP was rare by LAg (1/14, 0/5) and BioRad Avidity assays (2/14, 1/5) but more frequent by BED-CEIA (5/14, 3/5). Among recently-infected individuals (subtype B), 60% (15/25) were correctly classified by BED-CEIA, 88% (22/25) by BioRad Avidity and significantly fewer by LAg (48%, 12/25) compared to BioRad Avidity (p = 0.005) with a higher true-recency rate among non-B infections for all assays. CONCLUSIONS: This study using well-characterized specimens demonstrated lower FRRs for both avidity methods than with the BED-CEIA. For recently infected individuals the BioRad Avidity assay was shown to give the most accurate results.

An objective method was used to evaluate image quality and dose in mammography with synchrotron radiation and to compare them to standard units. It was performed systematically in the energy range of interest for mammography through the evaluation of the contrast and the measurement of the mean glandular dose. Synchrotron radiation measurements were performed at the ESRF and a slit was placed between the test object and the screen-film system in order to reduce scatter. The conventional films were obtained on mammography units with an anti-scatter grid. In a recent paper, it was shown that the use of synchrotron radiation leads to a noticeable improvement of the image quality-dose relationship (Moeckli et al. Phys. Med. Biol. 45(12)3509). The reason of that enhancement is partly due to the monochromaticity of the synchrotron beam and partly due to the use of a slit instead of a grid. The dose reduction with synchrotron radiation can be attributed to a better X-ray total transmission of the slit and the contrast improvement is due to the monochromaticity of the synchrotron beam.

The shape of the energy spectrum produced by an x-ray tube has a great importance in mammography. Many anode-filtration combinations have been proposed to obtain the most effective spectrum shape for the image quality-dose relationship. On the other hand, third generation synchrotrons such as the European Synchrotron Radiation Facility in Grenoble are able to produce a high flux of monoenergetic radiation. It is thus a powerful tool to study the effect of beam energy on image quality and dose in mammography. An objective method was used to evaluate image quality and dose in mammography with synchrotron radiation and to compare them to standard conventional units. It was performed systematically in the energy range of interest for mammography through the evaluation of a global image quality index and through the measurement of the mean glandular dose. Compared to conventional mammography units, synchrotron radiation shows a great improvement of the image quality-dose relationship, which is due to the beam monochromaticity and to the high intrinsic collimation of the beam, which allows the use of a slit instead of an anti-scatter grid for scatter rejection.

A fixed-exit monochromator has been constructed for computed tomography (CT) studies at the Medical Beamline of the European Synchrotron Radiation Facility. A non-dispersive pair of bent Laue-type crystals is used, and the first crystal is water-cooled. The monochromator operates at energies from 18 to 90 keV, and the maximum width of the beam is 150 mm. The performance of the monochromator is studied with respect to the beam intensity and energy distributions, and a close agreement is found between the calculated and experimental results. The intensity is between 10(9) and 10(10) photons s(-1) mm(-2) under typical operating conditions. The harmonic content of a 25 keV beam is about 30% at the minimum wiggler gap of 25 mm (field 1.57 T) and decreases by an order of magnitude when the gap is increased to 60 mm (field 0.62 T). The experimental set-up for CT studies includes dose monitors, goniometers and translation stages for positioning and scanning the object, and a 432-element linear-array Ge detector. Examples from phantom studies and in vivo animal experiments are shown to illustrate the spatial resolution and contrast of the reconstructed images.

The first operation of the European Synchrotron Radiation Facility (ESRF) medical beamline is reported in this paper. The goal of the angiography project is to develop a reduced risk imaging technique, which can be used to follow up patients after coronary intervention. After the intravenous injection of a contrast agent (iodine) two images are produced with monochromatic beams, bracketing the iodine K-edge. The logarithmic subtraction of the two measurements results in an iodine enhanced image, which can be precisely quantified. A research protocol has been designed to evaluate the performances of this method in comparison with the conventional technique. Patients included in the protocol have previously undergone angioplasty. If a re-stenosis is suspected, the patient is imaged both at the ESRF and at the hospital with the conventional technique, within the next few days. This paper reports the results obtained with the first patients. To date, eight patients have been imaged and excellent image quality was obtained.

The purpose of this work was to demonstrate the feasibility of a new imaging technique called synchrotron radiation computed tomography (SRCT). This technique leads to a direct assessment of the in vivo concentration of an iodine- or gadolinium-labeled compound. Rats bearing C6 glioma were imaged by MRI prior to the SRCT experiment. The SRCT experiments were performed after a 1.3 g I/kg (n = 5) or a 0.4 g Gd/kg (n = 5) injection. Finally, brains were sampled for histology. The SRCT images exhibited contrast enhancement at the tumor location. Ten minutes after injection, iodine and gadolinium tissular concentrations were equal to 0.80 ( ± 0.40) mg/cm3 and 0.50 ( ± 0.10) mg/cm3, respectively in the peripheral area of the tumor (respective background value: 0.20 ± 0.02 to 0.10 ± 0.01). Correlation to MRI and histology revealed that the contrast uptake occurred in the most vascularized area of the tumor. The present study summarizes the feasibility of in vivo SRCT to obtain quantitative information about iodine and gadolinium-labeled compounds. Beyond brain tumor pathology, the SRCT appears as a complementary approach to MRI and CT, for studying iodine- and gadolinium-labeled compounds by the direct achievement of the tissular concentration value in the tissue.

Impurity ion concentration and impurity ion temperature in the plasma gradient region as well as the scrape-off layer are essential parameters for understanding the physics of L- and H-mode transport and the transport barrier itself. To gain access to these properties, the well-established Li-beam diagnostic capabilities on both fusion devices at the Max-Planck-Institut fur Plasmaphysik (IPP) Garching [WENDELSTEIN 7-AS stellarator and the Axially Symmetric Divertor Experiment (ASDEX) Upgrade tokamak] have been extended to include the measurement of radial profiles of impurity ion densities and temperatures by means of charge-exchange spectroscopy. This paper describes the experimental setups on both devices and presents typical results of impurity ion investigations. Electron density measurements show excellent agreement with other diagnostics. In addition, several Lil spectral lines (2p → 2s, 3d → 2p, 4s → 2p, and 4d → 2p) have been measured to check the collisional-excitation Li-beam modeling, especially for collision processes involving higher Li(nl) states (n ≥ 3). The underlying database has been augmented by extensive investigations of lithium excitation processes. Cross sections for Li(2s → 2p) excitation by various impurity ions as well as proton impact Li(2l → nl) excitation have been calculated and measured in detail.

At the European Synchrotron Radiation Facility (ESRF) a beamport has been instrumented for medical research programs. Two facilities have been constructed for alternative operation. The first one is devoted to medical imaging and is focused on intravenous coronary angiography and computed tomography (CT). The second facility is dedicated to pre-clinical microbeam radiotherapy (MRT). This paper describes the instrumentation for the imaging facility. Two monochromators have been designed, both are based on bent silicon crystals in the Laue geometry. A versatile scanning device has been built for pre-alignment and scanning of the patient through the X-ray beam in radiography or CT modes. An intrinsic germanium detector is used together with large dynamic range electronics (16 bits) to acquire the data. The beamline is now at the end of its commissioning phase; intravenous coronary angiography is intended to start in 1999 with patients and the CT pre-clinical program is underway on small animals. The first in vivo images obtained on animals in angiography and CT modes are presented to illustrate the performances of these devices.

Three-dimensional multi-electrode systems with typical dimensions between 1 and 100 μm can be fabricated by semiconductor technology on glass or silicon substrates and used for stable trapping and/or manipulation of individual cells or micro-particles. Electric field frequencies in the MHz-range are used to achieve negative dielectrophoresis (repelling forces) in aqueous solution. This allows the creation of closed, dielectric field cages that trap cells or particles singly or as aggregates in free solution. To date, dielectric field cages have been analysed by dipole approximation. We show that this approach gives a good estimate for particles smaller than about a quarter of the electrode spacing in rotating electric field cages. For larger particles, quadrupole forces are significant. This is of great importance for, e.g., the force calibration of laser tweezers in dielectric cages. A knowledge of higher moments is necessary for understanding particle behaviour in non-rotating octode field cages.We evaluate the trapping efficiency of cages for Brownian particles, both analytically and by numerical integration of Langevin's equation. Single particles with effective diameters down to 35 nm should reliably trapped in micron field cages. Advantages and possible applications of field cages in biology, physics and chemistry are discussed.

The synthesis of a new Diels-Alder adduct 7 of [60]fullerene and a phthalocyaninenickel compound containing a longer spacer than the originally reported Diels-Alder adduct 1 is described. The bisenophilic hemiporphyrazinenickel compound 11 reacts with [60]fullerene to form a Diels-Alder adduct 12 containing two fullerene units. Spectroelectrochemical investigations of 7 and 12 reveal multiple reductions, which are attributed to the corresponding subunits of the molecules. In contrast to 1, the election acceptor properties of the [60]fullerene unit in both molecules have no influence on the electronic properties of the phthalocyanine and hemiporphyrazine, respectively.

Acta crystallographica / A 72(a1), s14 - s14(2016). doi:10.1107/S2053273316099770, Published by Blackwell, Oxford [u.a.]

Electrode reactions near the surface of planar platinum and gold ultramicroelectrodes in aqueous electrode solutions were visualized by fluorescence microscopy. Millisecond pulses of direct current (0.5-5 V dc) mused pH alterations in the vicinity of the electrodes and in the interelectrode gaps. These changes mused differences in the fluorescence intensity of fluorescein or of its dextran conjugate (MW 2×10 6 ), allowing visualization. Redox reactions at the electrodes created pH gradient patterns on a micrometer and submicrometer scale. It is possible to delay the diffusional dissipation of the electrogenerated «protonation clouds» by adding up to 30% (w/v) poly(vinylpyrrolidone) (MW 7.5×10 5 ). We used 50, 20, 10, and 3 μm wide electrode slips with either dc, pulsed dc, or dc-shifted ac (kHz-MHz) excitation. Steep pH gradients could be moved perpendicular to the electrode slip array. Traveling pH waves with speeds of about ∼1 mm/s could be generated. We have developed a numerical procedure for modeling the time-dependent concentration of electroactive species. The numerical pH patterns are in good agreement with the experimentally obtained ones. Electrotitration and its numerical modeling open new perspectives. Micro- and ultramicroelectrodes should and applications in analytical chemistry and biomedical research. Titration techniques within microcompartments may now be practicable. The visualization of cathodically driven electrodes is also useful for assessing the working state of microelectrode arrays

Analyzer-based imaging is a powerful phase-sensitive technique that generates improved contrast compared to standard absorption radiography. Combining numerically two images taken on either side at +/-1/2 of the full width at half-maximum (FWHM) of the rocking curve provides images of "pure refraction" and of "apparent absorption." In this study, a similar approach is made by combining symmetrical images with respect to the peak of the analyzer rocking curve but at general positions, +/-alpha.FWHM. These two approaches do not consider the ultrasmall angle scattering produced by the object independently, which can lead to inconsistent results. An accurate way to separately retrieve the quantitative information intrinsic to the object is proposed. It is based on a statistical analysis of the local rocking curve, and allows one to overcome the problems encountered using the previous approaches. (C) 2003 American Institute of Physics.

This study aimed at investigating the presence and distribution of fluorotelomer alcohols (FTOHs), perfluorooctane sulfonate (PFOS) and perfluorooctanoate (PFOA) in house dust to evaluate human exposure to these compounds via dust ingestion. 31 house dust samples were collected from Bavaria, Germany and analyzed for 4:2, 6:2, 8:2 and 10:2 FTOH, PFOS and PFOA. PFOA was the dominant compound in 79% of the dust samples, followed by PFOS and 8:2 FTOH, while 4:2 FTOH was not detected in any samples. The total concentration of per- and polyfluorinated compounds (PFCs) varied from 32.2 to 2456 ng/g. In addition, the total ingestion rate for PFCs was 0.4–135 ng/d for adults and 5.1–246 ng/d for toddlers, and the highest 8:2 FTOH-based PFOA intake via indoor dust was 0.24 ng/d for adults and 0.44 ng/d for toddlers. Overall, the results of this study demonstrate that dust ingestion is a minor pathway for human exposure to these PFCs; the PFC ingestion via indoor dust is generally low, and only under a worst scenario high intakes have to be expected for toddlers.

Single particles can be manipulated by applying high frequencies to ultramicro electrode arrays fabricated on planar structures. Heat production can be reduced to the extent that intense electric fields can be applied even to unmodified cell culture media. Animal cells grow normally in the high field (up to 100 kV/m) between such continuously energized multielectrodes. As with laser tweezers (1-3), this technique can capture particles and cells in field traps, generate linear movement, and permit cell cultivation. It can also produce micropatterns of pH gradients, field-cast objects, and control cell adhesion. These microtools may be combined to develop cell separators, microsensors, and controlled-biocompatibility surfaces.

The forces acting on dielectric particles and living cells exposed to alternating and rotating fields generated by three-dimensional multi-electrode arrangements are investigated. Numerical procedures are described for the calculation of the electric field distribution and forces. The physical treatment considers electrodes of any shape and dielectric particles of complex structure. Particle and cell trapping are based on negative dielectrophoretic forces produced by high-frequency a.c. or rotating electric fields up to 400 MHz. Various multi-electrode systems were realised in commercially fabricated microelectrode systems, and tested for their ability to move and assemble microparticles or living cells without contact with the electrodes. The field distribution and accuracy of phase-controlled power application was tested using individual artificial particles trapped in the electric field cage. Position and trajectories of particle motion were measured. The paper gives an overview of electrode and field cage design in the microscale range.

Procedural modeling for architectural scenes was as yet limited to static objects only. We introduce a novel extension layer for shape grammars which creates a skeletal system for posing and interactive manipulation of generated models. Various models can be derived with the same set of parametrized rules for geometric operations. Separation of geometry generation and pose synthesis improves design efficiency and reusability. Moreover, by formal analysis of production rules we show how to efficiently update complex kinematic hierarchies created by the skeletons, allowing state-of-the-art interactive visual rule editing.

International audience; BACKGROUND: K-edge digital subtraction angiography (KEDSA) combined with the tunability of synchrotron beam yields an imaging technique that is highly sensitive to low concentrations of contrast agents. Thus, contrast agent can be administered intravenously, obviating the need for insertion of a guided catheter to deliver a bolus of contrast agent close to the target tissue. With the high-resolution detectors used at synchrotron facilities, images can be acquired at high spatial resolution. Thus, the KEDSA appears particularly suited for studies of neurovascular pathology in animal models, where the vascular diameters are significantly smaller than in human patients. MATERIALS AND METHODS: This feasibility study was designed to test the suitability of KEDSA after intravenous injection of iodine-based contrast agent for use in a pig model. Four adult male pigs were used for our experiments. Neurovascular angiographic images were acquired using KEDSA with a solid state Germanium (Ge) detector at the European Synchrotron Radiation Facility (ESRF) in Grenoble, France. RESULTS: After intravenous injection of 0.9 ml/kg iodinated contrast agent (Xenetix), the peak iodine concentrations in the internal carotid and middle cerebral arteries reached 35 mg/ml. KEDSA images in radiography mode allowed the visualization of intracranial arteries of less than 1.5mm diameter.

Background Although the quality of imaging techniques available for neurovascular angiography in the hospital environment has significantly improved over the last decades, the equipment used for clinical work is not always suited for neurovascular research in animal models. We have previously investigated the suitability of synchrotron-based K-edge digital subtraction angiography (KEDSA) after intravenous injection of iodinated contrast agent for neurovascular angiography in radiography mode in both rabbit and pig models. We now have used the KEDSA technique for the acquisition of three-dimensional images and dual energy CT. Materials and methods All experiments were conducted at the biomedical beamline ID 17 of the European Synchrotron Radiation Facility (ESRF). A solid state germanium (Ge) detector was used for the acquisition of image pairs at 33.0 and 33.3 keV. Three-dimensional images were reconstructed from an image series containing 60 single images taken throughout a full rotation of 360°. CT images were reconstructed from two half-acquisitions with 720 projections each. Results The small detector field of view was a limiting factor in our experiments. Nevertheless, we were able to show that dual energy CT using the KEDSA technique available at ID 17 is suitable for neurovascular research in animal models.

Fluorotelomer alcohols (FTOH) are widely used substances that were detected even in remote regions of the world. For the determination of FTOH in the atmosphere, appropriate sampling techniques are needed. In this study, triolein-filled low-density polyethylene tubes were used as semipermeable membrane devices (SPMD) and tested for their suitability as passive air samplers for FTOH. Partitioning to and from SPMD were investigated for four FTOH of different chain length and concentration levels in laboratory and field experiments. FTOH were extracted by liquid–liquid extraction with acetonitrile:n-hexane 1:1 and determined by gas chromatography (GC)-positive ion chemical ionisation mass spectrometry (MS). FTOH behaved differently depending on applied concentrations. At high FTOH levels, compound passage through the membrane and uptake appeared to be best for 6:2 FTOH, but passage of long-chain FTOH was in the same order of magnitude. At low FTOH concentration levels, mass transfer and uptake was best for short-chain FTOH. Partitioning of 4:2 FTOH to SPMD exceeded partitioning of 10:2 FTOH by nearly two orders of magnitude. FTOH partitioning to SPMD seems to be dependent on the fluorinated chain length and controlled by the SPMD membrane acting as a barrier. Migration of long-chain FTOH through the membrane was hampered, probably due to the oleophobic properties of the fluorinated alkyl chain. Because of the constricted diffusion of FTOH through the SPMD membrane at low FTOH levels, an adequate accumulation in the passive sampler is prevented. Thus, sensitivity of the analytical method in combination with the enrichment of FTOH in SPMD was not sufficient to achieve adequate method detection limit at low FTOH levels. Application of SPMD as passive air samplers for FTOH did not seem to be a suitable method for environmentally relevant FTOH concentrations. As a consequence, we can only recommend the use of SPMD for FTOH of presumably high contamination levels.

The high temporal, spatial and contrast resolution of synchrotron radiation imaging (SYRI) allows the measurement of the residual density of an injected contrast medium with high precision and delivers absolute values. This was exploited with measurements on pigs where it could be shown that the identification and characterization of the relevant compartments and their structures allows to record the time dependent contrast medium density in arteries, the myocardium and the veins separately. With an adapted computer based flow model the absolute local determination of the perfusion and for extracellular contrast media (as Gadovise (R)) the permeability through the capillary membrane could be obtained. Model prediction include the option of flow reserve measurement at baseline.

A transformation system for Enterococcus faecalis was developed which uses untreated (i.e. non-protoplasted) cells and the electroporation technique. The optimized protocol resulted in transformation efficiencies of up to 4 × 10 6 transformants per μg of plasmid DNA. All strains of E. faecalis tested could be transformed by this method, albeit with differing transformation efficiencies. Using the protocol optimized for E. faecalis we successfully transformed Enterococcus faecium, E. hirae, E. malodoratus and E. mundtii .

As possible precursors of PFOA, fluorotelomer alcohols are a class of highly fluorinated and volatile compounds. Although they are widespread in the environment, little toxicity data is available. The present study focused on testing the population growth impairment potential of FTOH. Moreover, certain efforts were made to find the possible effect mechanism of these compounds.The growth inhibition test was made both in an open system (96-well microplates) and in a closed system (closed flasks). In addition, cells were stained with acridine orange and observed under fluorescence microscopy at 488 nm. Furthermore, direct membrane damage was checked by measuring LDH leakage.For 8:2 FTOH and 10:2 FTOH, no growth inhibition was found in either of the systems. In contrast, 4:2 FTOH interfered with population growth in the closed system (EC(50) = 276.1 mg/L), whereas, 6:2 FTOH had an influence on population growth both in the closed system (EC(50) = 64.3 mg/L) and in the open system. Macronucleus destruction was observed with 6:2 FTOH. No direct membrane damage was detectable.With a closed system, 4:2 and 6:2 FTOH were found to be capable of impairing population growth. However, this potential was to a certain extent underestimated. With the help of the air-water distribution coefficient, the real EC(50) was estimated within the interval [203.2, 276.1] mg/L and [14.7, 64.3] mg/L for 4:2 and 6:2 FTOH, respectively. Some evidence, such as the absence of direct membrane or macronucleus damage, indicate that certain FTOH could likely cause apoptosis. But the exact effect mechanism could not be determined on the basis of the present results.Comparing the results from the two test systems, tests in a closed system are more reliable for testing these volatile compounds with Tetrahymena thermophila than in an open system.The present study has highlighted several future research directions. For ecotoxicological risk assessment of FTOH, their distribution and environmental fate should be determined. To understand the effect mechanism, more tests could be conducted to test whether apoptosis is caused. Finally, in order to standardize test procedure in a closed system, more compounds should be investigated in the closed system to clarify the sensitivity of the test procedures.

International audience; This study was approved by the local research ethics committee, and patient informed consent was obtained. The purpose of this study was to demonstrate that high-spatial-resolution low-dose analyzer-based x-ray computed tomography (CT) can substantially improve the radiographic contrast of breast tissue in vitro when compared with that attained by using diagnostic mammography and CT. An excised human breast tumor was examined by using analyzer-based x-ray imaging with synchrotron radiation. The correspondence between analyzer-based x-ray images and diagnostic mammograms, CT images, and histopathologic findings was determined. Calcifications and fine details of soft tissue, which are at the contrast detection limit on diagnostic mammograms, are clearly visible on planar analyzer-based x-ray images. Analyzer-based x-ray CT yields high contrast from smoothly varying internal structures, such as tumorous mass lesions, corresponding to information on actual structures seen at histopathologic analysis. The mean glandular dose of 1.9 mGy in analyzer-based x-ray CT is approximately equivalent to the dose administered during single-view screening mammography. The improved visibility of mammographically indistinguishable lesions in vitro suggests that analyzer-based x-ray CT may be a valuable method in radiographic evaluation of the breast, thereby justifying further investigations.

PCDD/Fs (polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans) and PCBs (polychlorinated biphenyls) in soot dust, fume and contaminated air with burning plastic floor and electronic scrap (E-wastes) were sampled employing semi permeable membrane devices (SPMDs). It was found that the emitted PCDFs were dominant compared to PCDDs collected from samples. However the PCDD/Fs and PCBs congener profiles were different between soot dust, fume sample and contaminated air sample. The total amounts of PCBs were much higher than that of PCDD/Fs, but the contribution of them to the WHO-TEQ was less than that of PCDD/Fs. The total amounts PCDD/Fs, PCBs and WHO-TEQ is quite high in soot dust, fume sample than that in contaminated air sample.

USAXS and SAXS patterns from cancer-bearing human breast tissue samples were recorded at beamline ID02 of the ESRF using a Bonse–Hart camera and a pinhole camera. The samples were classified as being ductal carcinoma, grade II, and ductal carcinoma in situ, partly invasive. The samples included areas of healthy collagen, invaded collagen, necrotic ducts with calcifications, and adipose tissue. The scattering patterns were analyzed in different ways to separate the scattering contribution and the direct beam from the observed rocking curve (RC) of the analyzer. It was found that USAXS from all tissues was weak, and the effects on the analyzer RC were observed only in the low-intensity tails of the patterns. The intrinsic RC was convolved with different model functions for the impulse response of the sample, and the best fit with experiment was obtained by the Pearson VII function. Significantly different distributions for the Pearson exponent m were obtained in benign and malignant regions of the samples. For a comparison with analyzer-based imaging (ABI) or diffraction enhanced imaging (DEI) a “long-slit” integration of the patterns was performed, and this emphasized the scattering contribution in the tails of the rocking curve. © 2008 Elsevier Ireland Ltd. All rights reserved.

Gaseous emissions of combusted electronic scrap, PVC, carpet and wood were monitored for polycyclic aromatic hydrocarbons (PAHs) by simultaneous use of semipermeable membrane devices (SPMDs) and shoots of spruce needles (Picea abies). It was found that phenanthrene, acenaphthylene and fluorene were the dominating PAHs in all samples. SPMDs and needles mainly sequestered PAH associated with the vapor phase. Particle-bound PAHs were only detected in small amounts, at which the needles tended to uptake more of these compounds in comparison to the SPMDs. Nevertheless, the logarithm of the concentrations of PAHs analyzed in both passive samplers after the same sampling period exhibited a significant linear correlation with correlation coefficients larger than 0.8073. SPMDs and spruce needles can complement each other in passive air sampling for compounds with a preference to the gas phase rather than aerosols.

We used sub-micron metal rod decorated surfaces, 'nano-lawn' structures, as a substrate to study cell-to-cell and cell-to-surface interactions of primary murine astrocytes. These cells form thin membranous tubes with diameters of less than 100 nm and a length of several microns, which make contact to neighboring cells and the substrate during differentiation. While membrane protrusions grow on top of the nano-lawn pillars, nuclei sink to the bottom of the substrate. We observed gondola-like structures along those tubes, suggestive of their function as transport vehicles. Elements of the cytoskeleton such as actin fibers are commonly believed to be essential for triggering the onset and growth of tubular membrane protrusions. A rope-pulling mechanism along actin fibers has recently been proposed to account for the transport or exchange of cellular material between cells. We present evidence for a complementary mechanism that promotes growth and stabilization of the observed tubular protrusions of cell membranes. This mechanism does not require active involvement of actin fibers as the formation of membrane protrusions could not be prevented by suppressing polymerization of actin by latrunculin B. Also theoretically, actin fibers are not essential for the growing and stability of nanotubes since curvature-driven self-assembly of interacting anisotropic raft elements is sufficient for the spontaneous formation of thin nano-tubular membrane protrusions.

[1] Nitrate pollution from agricultural activities often persistently affects groundwater quality due to long residence times in the vadose and saturated zone. In this study we used a lumped parameter approach to estimate the residence time of groundwater and nitrate from the agriculturally used Jahna-Aue drinking water catchment in Saxonia, Germany. Inverse modeling of measured concentrations of tritium and tritiogenic 3He revealed consistent mean residence times between 25 and 50 years for the young, nitrate-rich groundwater component, and high contributions (>75%) of an old, tracer-free, and nitrate-poor groundwater. The obtained age distributions are in accordance with the complex hydrogeological situation of the investigated catchment, suggesting that the shallow and therefore most vulnerable part of the aquifer is not connected to the production wells. High residence times are supported by low concentrations of CFCs and by radiogenic 4He as an independent age indicator. CFC concentrations only yield lower age limits due to identified problems with CFC contamination. Using the tracer-calibrated age distributions, future nitrate concentrations in the production wells most probably will remain below the drinking water limit because of the high dilution with old, nitrate-poor groundwater. Deterioration of the groundwater quality with respect to nitrate may occur if the groundwater pumping regime is changed so that the fraction of the younger, nitrate-bearing water is increased.

New applications of template-generated structures and surfaces are foreseen in microelectronic joining, photonics, and analytical chemistry. They require a special tuning of morphological and topological parameters. High-resolution imaging techniques allow for optimising surface properties and grain size of metal-rod decorated surfaces. Submicron wires and more complex "lawn"-structures with diameters of 600 ? 50 nm have been produced by galvanic deposition at porous polymer templates. Their application for low-temperature interconnect formation is under evaluation. First results indicate that single-metal and layered "nano-lawn" can be attractive for microsystem technology in general, but also in analytical chemistry and related fields. Template techniques are discussed and experimental approaches to use gold nano-lawn are presented. The development of new materials and appropriate techniques will be useful for future packaging technologies of (micro-)electronics to come.

Experimental evidence on long, thin tubular structures (with or without transport gondolas) in giant phospholipid vesicles indicates an important role of phospholipid nanotubes in intracellular and intercellular transport and communication. In this work, we present evidence that nanotubular structures similar to the ones observed in giant phospholipid vesicles exist also in fully differentiated cells. We have used sub-micron metal-rod decorated surfaces, “nanolawn” structures, as a substrate to study cell–cell and cell–surface interactions of primary murine astrocytes. Astrocytes are the major cell group of the brain, comprising about 50% of the cells. They support neurons both physically as a cell matrix and physiologically by providing a stable microenvironment and growth factors. Astrocytes form multicellular syncytia in vivo that provide neuronal homeostasis by taking up neurotransmitters and buffering the ionic content of the extracellular medium in the brain. Using nanolawn as the matrix for differentiation, we could observe how astrocytes form nanotubular protrusions to make contact with the matrix and each other. The thin tubular structures were very similar to those in pure phospholipid systems. Furthermore, gondolas on these nanotubes have been observed suggesting a transport function for cellular material. It could be theoretically shown that curvature-induced self-assembly of interacting anisotropic membrane components may lead to the spontaneous formation of thin nanotubular membrane protrusions in systems of giant liposomes as well as in astrocytes. This self-assembly may represent a relevant physical mechanism of nanotube formation even if membrane skeleton elements, such as actin fibers, were not essential for the nanotube formation.

Introduction : The aim of our study was to analyze the occurrence and evolution of HIV-1 integrase polymorphisms during the HIV-1 epidemic in Germany prior to the introduction of the first integrase inhibitor raltegravir in 2007. Material and Methods : Plasma samples from drug-naive HIV-1 infected individuals newly diagnosed between 1986 and 2006 were used to determine PCR-based population sequences of the HIV-1 integrase (amino acids 1–278). The HIV-1 subtype was determined using the REGA HIV-1 subtyping tool. We calculated the frequency of amino acids at each position of the HIV-1 integrase in 337 subtype B strains for the time periods 1986–1989, 1991–1994, 1995–1998, 1999–2002, and 2003–2006. Positions were defined as polymorphic if amino acid variation was >1% in any period. Logistic regression was used to identify trends in amino acid variation over time. Resistance-associated mutations were identified according to the IAS 2013 list and the HIVdb, ANRS and GRADE algorithms. Results : Overall, 56.8% (158/278) amino acid positions were polymorphic and 15.8% (25/158) of these positions exhibited a significant trend in amino acid variation over time. Proportionately, most polymorphic positions (63.3%, 31/49) were detected in the N-terminal zinc finger domain of the HIV-1 integrase. Motifs and residues essential for HIV-1 integrase activity were little polymorphic, but within the minimal non-specific DNA binding region I220-D270 up to 18.1% amino acid variation was noticed, including four positions with significant amino acid variation over time (S230, D232, D256, A265). No major resistance mutations were identified, and minor resistance mutations were rarely observed without trend over time. E157Q considered by HIVdb, ANRS, and GRADE algorithms was the most frequent resistance-associated polymorphism with an overall prevalence of 2.4%. Conclusions : Detailed knowledge of the evolutionary variation of HIV-1 integrase polymorphisms is important to understand the development of resistance in the presence of the drug. Our results will contribute to define the relevance of integrase polymorphisms in HIV-strains resistant to integrase inhibitors and to improve resistance interpretation algorithms. (Published: 2 November 2014) Citation: Abstracts of the HIV Drug Therapy Glasgow Congress 2014 Meixenberger K et al. Journal of the International AIDS Society 2014, 17(Suppl 3) :19746 http://www.jiasociety.org/index.php/jias/article/view/19746 | http://dx.doi.org/10.7448/IAS.17.4.19746

The purpose of this work was to assess the imaging performance of an indirect conversion detector (taper optics CCD; FReLoN' camera) in terms of the modulation transfer function (MTF), normalized noise power spectrum (NNPS) and detective quantum efficiency (DQE). Measurements were made with a synchrotron radiation laminar beam at various monochromatic energies in the 20-51.5 keV range for a gadolinium-based fluorescent screen varying in thickness; data acquisition and analysis were made by adapting to this beam geometry protocols used for conventional cone beams. The pre-sampled MTFs of the systems were measured using an edge method. The NNPS of the systems were determined for a range of exposure levels by two-dimensional Fourier analysis of uniformly exposed radiographs. The DQEs were assessed from the measured MTF, NNPS, exposure and incoming number of photons. The MTF, for a given screen, was found to be almost energy independent and, for a given energy, higher for the thinnest screen. At 33 keV and for the 40 (100) microm screen, at 10% the MTF is 9.2 (8.6) line-pairs mm(-1). The NNPS was found to be different in the two analyzed directions in relation to frequency. Highest DQE values were found for the combination 100 microm and 25 keV (0.5); it was still equal to 0.4 at 51.5 keV (above the gadolinium K-edge). The DQE is limited by the phosphor screen conversion yield and by the CCD efficiency. At the end of the manuscript the results of the FReLoN characterization and those from a selected number of detectors presented in the literature are compared.

Traffic- and urban-influenced areas are prone to enhanced pollution with products of incomplete combustion of fossil fuels and biomass such as black carbon or polycyclic aromatic hydrocarbons (PAHs). Black carbon is composed of aromatic and graphitic structures and may act as a carrier for pollutants such as PAHs and heavy metals. However, little is known about possible contributions of traffic-derived black carbon to the black carbon inventory in soils. Similar uncertainties exist regarding the contribution of different pollutant sources to total PAH and black carbon contents. Therefore, the objective of this study was to quantify the importance of traffic pollution to black carbon and PAH inventories in soils. PAH contamination of soils adjacent to a major German highway in the urban area of Bayreuth with about 50,000 vehicles per day was in the same order of magnitude compared to highway-close soils reported in other studies. Using molecular (black carbon and PAHs) and compound-specific stable carbon isotope evidence (PAHs) it was demonstrated that this contamination originated not only from automobile exhausts, here primarily diesel, but also from tire abrasion and tailpipe soot which significantly contributed to the traffic-caused black carbon and PAH contamination. Low molecular weight PAHs were more widely transported than their heavy molecular counterparts (local distillation), whereas highway-traffic-caused black carbon contamination was distributed to at least 30 m from the highway. On the other hand, urban fire exhausts were distributed more homogeneously among the urban area.

Twenty-eight human breast tumour specimens were studied with small-angle x-ray scattering (SAXS), and 10 of those were imaged by the diffraction enhanced x-ray imaging (DEI) technique. The sample diameter was 20 mm and the thickness 1 mm. Two examples of ductal carcinoma are illustrated by histology images, DEI, and maps of the collagen d-spacing and scattered intensity in the Porod regime, which characterize the SAXS patterns from collagen-rich regions of the samples. Histo-pathology reveals the cancer-invaded regions, and the maps of the SAXS parameters show that in these regions the scattering signal differs significantly from scattering by the surrounding tissue, indicating a degradation of the collagen structure in the invaded regions. The DEI images show the borders between collagen and adipose tissue and provide a co-ordinate system for tissue mapping by SAXS. In addition, degradation of the collagen structure in an invaded region is revealed by fading contrast of the DEI refraction image. The 28 samples include fresh, defrosted tissue and formalin-fixed tissue. The d-values with their standard deviations are given. In the fresh samples there is a systematic 0.76% increase of the d-value in the invaded regions, averaged over 11 samples. Only intra-sample comparisons are made for the formalin- fixed samples, and with a long fixation time, the difference in the d-value stabilizes at about 0.7%. The correspondence between the DEI images, the SAXS maps and the histo-pathology suggests that definitive information on tumour growth and malignancy is obtained by combining these x-ray methods.

The authors previously provided evidence of synchrotron radiation computed tomography (SRCT) efficacy for quantitative in vivo brain perfusion measurements using monochromatic X-ray beams. However, this technique was limited for small-animal studies by partial volume effects. In this paper, high-resolution absolute cerebral blood volume and blood–brain barrier permeability coefficient measurements were obtained on a rat glioma model using SRCT and a CCD camera (47 × 47 μm2 pixel size). This is the first report of in vivo high-resolution brain vasculature parameter assessment. The work gives interesting perspectives to quantify brain hemodynamic changes accurately in healthy and pathological small animals.

The combination of X-ray 'propagation-based' and 'analyzer-based' phase-contrast imaging with a perfect crystal-analyzer is investigated. The image pattern produced using this 'hybrid' imaging technique presents peculiar features that can be interpreted as a mixture of the two independent phase-contrast signals. A quantitative analysis has been performed in terms of signal-to-noise ratio for the three techniques considered in this paper. Results show that in the 'hybrid imaging' technique this parameter has a weaker dependence on the angular alignment of the crystal analyser with respect to the 'analyser-based' imaging. This pioneering experiment indicates that this hybrid imaging technique might permit simultaneous advantage of the specific features of the two imaging methods to be taken.

Different modalities for imaging cancer-bearing breast tissue samples are described and compared. The images include clinical mammograms and computed tomography (CT) images, CT images with partly coherent synchrotron radiation (SR), and CT and radiography images taken with SR using the diffraction enhanced imaging (DEI) method. The images are evaluated by a radiologist and compared with histopathological examination of the samples. Two cases of lobular carcinoma are studied in detail. The indications of cancer are very weak or invisible in the conventional images, but the morphological changes due to invasion of cancer become pronounced in the images taken by the DEI method. The strands penetrating adipose tissue are seen clearly in the DEI-CT images, and the histopathology confirms that some strands contain the so-called 'Indian file' formations of cancer cells. The radiation dose is carefully measured for each of the imaging modalities. The mean glandular dose (MGD) for 50% glandular breast tissue is about 1 mGy in conventional mammography and less than 0.25 mGy in projection DEI, while in the clinical CT imaging the MGD is very high, about 45 mGy. The entrance dose of 95 mGy in DEI-CT imaging gives rise to an MGD of 40 mGy, but the dose may be reduced by an order of magnitude, because the contrast is very large in most images.

In mammography, the imagecontrast and dose delivered to the patient are determined by the x-ray spectrum and the scatter to primary ratio S/P. Thus the quality of the mammographic procedure is highly dependent on the choice of anode and filter material and on the method used to reduce the amount of scatteredradiation reaching the detector.Synchrotron radiation is a useful tool to study the effect of beam energy on the optimization of the mammographic process because it delivers a high flux of monochromatic photons. Moreover, because the beam is naturally flat collimated in one direction, a slot can be used instead of a grid for scatter reduction. We have measured the ratio S/P and the transmission factors for grids and slots for monoenergetic synchrotron radiation. In this way the effect of beam energy and scatter rejection method were separated, and their respective importance for image quality and dose analyzed. Our results show that conventional mammographic spectra are not far from optimum and that the use of a slot instead of a grid has an important effect on the optimization of the mammographic process. We propose a simple numerical model to quantify this effect.

Small-angle X-ray scattering (SAXS) patterns from breast tissue samples are compared with their histology. Formalin fixed human breast tissue specimens containing ductal and lobular carcinoma were studied. Histo-pathological information is compared with the scattering data, and there is a clear spatial correlation. Supra-molecular organisation of collagen fibrils is modelled and the model is used to create scattering maps. The model parameters include the axial periodicity (d-spacing), radius and packing of the fibrils, and these are derived from comparison with the experimental scattering patterns. Thed-spacing is to 0.5% larger in malignant zones of the tumours than in the healthy zones. There are also characteristic differences in the fibril diameter and packing.

Shifting the attention from simple static depicting to dynamical generation of visualizations smart graphics can be seen as the next step in the evolution of presentation techniques. A new field of interest for these techniques is the Web which arises the question of how to adopt this new pattern. Based on the Model-View-Controller (MVC) paradigm we developed a generic architecture that allows for user interaction, component separation, adaptivity to environment and user needs and dynamic presentations. By introducing a client side presentational logic component the graphic evolves from a simple presentation to an intelligent visualization that valuates data and presents only the result relevant to the user. We consequently introduce the possibility of completely changing the whole presentation including the user interface by adaptation of the valuation basis. Because this is done by the graphic autonomously the server does not have to be contacted. In order to demonstrate our proposed conceptual approach, we implemented a prototype system by using the techniques available in a Web context.

Six excised human breast tissue specimens carrying benign and malignant tumours were examined with the diffraction-enhanced imaging technique. Diffraction-enhanced images were compared with diagnostic screen-film mammograms and the correlation with histological information of the specimens was established. The enhanced visibility of calcifications, some of which were smaller than 0.15 mm in diameter, is reported in detail. Fine details of the structures such as strands of collagen and contours between glandular and adipose tissue, which are barely visible at the contrast detection limit in the conventional absorption-based mammograms, are clearly visible in the diffraction-enhanced images. Microscopic study of the stained histopathological sections unequivocally confirms the correlation of the radiographic findings with the morphologic changes in specimens. An increased soft tissue contrast and a combination of information obtained with disparate diffraction-enhanced images provide better visibility of mammographically indistinguishable features. This kind of additional structural information of the breast tissue is required to improve assessment accuracy and earlier detection of the breast lesions. These advances in image quality make the method a very promising candidate for mammography.

Two X-ray phase-contrast imaging techniques are compared in a quantitative way for future mammographic applications: Diffraction Enhanced Imaging (DEI) and Propagation. The first uses an analyzer crystal after the sample acting as an angular filter for X-rays refracted by the sample. The latter simply uses the propagation (Fresnel diffraction) of the monochromatic and partially coherent X-ray beam over large distances. Experiments to compare both modalities have been performed at the Topography Beamline of the European Synchrotron Radiation Facility. The respective set-ups and experimental parameters are described in detail. Depending on the object properties, the two techniques present a difference in area contrast and edge visibility. DEI shows an enhancement of area contrast for positions of the crystal corresponding to the tails of its rocking curve (RC) and a similar increase but inverted is also visible at the peak of its RC. At the tails, the contrast is mainly produced by ultra small angle scattering, at the peak, it is due to absorption and scatter rejection by the analyzer. At the flanks, it may disappear when attenuation and scattering effects compensate each other. However, an enhancement of the object edges is clearly noticeable, which mainly corresponds to the refracted part. Propagation reveals an improvement of the edge visibility with the distance and shows negligible area contrast for non-absorbing, large structures.