Three-dimensional investigation and scoring of extracellular matrix remodeling during lung fibrosis using multiphoton microscopy

The organization of collagen during fibrotic processes is poorly characterized because of the lack of appropriate methodologies. Here we show that multimodal multiphoton microscopy provides novel insights into lung fibrosis. We characterize normal and fibrotic pulmonary tissue in the bleomycin model, and show that second-harmonic generation by fibrillar collagen reveals the micrometer-scale three-dimensional spatial distribution of the fibrosis. We find that combined two-photon excited fluorescence and second-harmonic imaging of unstained lung tissue allows separating the inflammatory and fibrotic steps in this pathology, underlining characteristic features of fibroblastic foci in human Idiopathic Pulmonary Fibrosis samples. Finally, we propose phenomenological scores of lung fibrosis and we show that they unambiguously sort out control and treated mice, with a better sensitivity and reproducibility in the subpleural region. These results should be readily generalized to other organs, as an accurate method to assess extracellular matrix remodeling during fibrosis.     

Multiscale proper generalized decomposition based on the partition of unity

Solutions of partial differential equations could exhibit a multiscale behavior. Standard discretization techniques are constraints to mesh up to the finest scale to predict accurately the response of the system. The proposed methodology is based on the standard proper generalized decomposition rationale; thus, the PDE is transformed into a nonlinear system that iterates between microscale and macroscale states, where the time coordinate could be viewed as a 2D time, representing the microtime and macrotime scales. The macroscale effects are taken into account because of an FEM-based macrodiscretization, whereas the microscale effects are handled with unidimensional parent spaces that are replicated throughout the domain. The proposed methodology can be seen as an alternative route to circumvent prohibitive meshes arising from the necessity of capturing fine-scale behaviors.     

The effects of photic driving on mood states

The capacity to maintain vigilance generally falls with time on task. However, it has been suggested that, for example, the effects of sleep loss need a rather long time on task to become evident. The present experiment examined when significant deterioration of performance occurred in a 34-min visual vigilance task (with 32 signals) given to twelve subjects every 3 h across 64 h without sleep. Results from the whole test, the first eight signals, and even the first signal varied significantly across the experiment and were significantly lower than baseline after 24 h awake. The rate of decline over time on task was similar across the experiment. Less than half the misses could be attributed to electrophysiologically defined sleepiness. It was concluded that there is no "safe" duration of a monotonous task if the situation is undemanding and boring, but that the effect may become immediately evident. This may have practical implications in terms of safety.     

Geometrical isomers of linolenic acid in low-calorie spreads marketed in France

The fatty acid compositions of 20 samples of low-calorie spreads marketed in France have been examined by gasliquid chromatography (GLC) of their isopropyl esters on a fused silica capillary column coated with 100% cyanopropyl polysiloxane. Spreads containing linolenic acid at a level of 2.3% or higher (5 out of the 20 samples under study) also containtrans- 18:3 isomers. These were identified, after fractionation of their isopropyl esters by thin-layer chromatography (TLC) on silica-gel plates impregnated with AgNO₃, by GLC on two capillary columns of different polarities and comparison of their equivalent chain lengths with those of authentic standards. Identifications were supported by GLC/mass spectrometry of the dimethyl esters resulting from ozonolysis in BF₃/methanol of the monoenes isolated by AgNO₃-TLC after hydrazine reduction of 18:3 isomers. 9c,12c,15t-18:3 and 9t,12c,15c-18:3 were found to be the most abundant 18:3 isomers in the spreads, with small amounts of 9c,12t,15c-18:3. These isomers occurred in the relative proportions 52–55, 41–42 and 4–6%, respectively. These proportions are independent of the origin of the sample. The tentatively identified 9t,12c,15t-18:3 also occurred in some instances. In 2 of the spreads, total geometrical isomers of linolenic acid accounted for 0.9–1% of the total fatty acids (up to 28% of the total 18:3n-3 fraction). The presence of 18:3n-3 geometrical isomers in the spreads is likely due to rapeseed or soybean oils that were deodorized under rather harsh conditions before these were blended with other fats or oils. Partial hydrogenation of these oils may also contribute to accumulation of the same linolenic acid isomers in the spreads.     

Metal transfer to plants grown on a dredged sediment: use of radioactive isotope 203Hg and titanium

Improperly disposed of dredged sediments contaminated with metals may induce long-term leaching and an increase of metal concentrations in ground waters and vegetal cover plants. The objective of the study was to quantify the sediment-to-plant transfer of Cu, Pb, Hg and Zn with a particular focus on the pathway of Hg and to determine whether the establishment of vegetal cover modifies the metal availability. A pot experiment with rape (Brassica napus), cabbage (Brassica oleraccea) and red fescue (Festuca rubra) was set up using a sediment first spiked with the radioisotope 203Hg. Zinc concentrations (197-543 mg kg(-1) DM) in leaves were higher than Cu concentration (197-543 mg kg(-1) DM), Pb concentration (2.3-2.6 mg kg(-1) DM) and Hg concentration (0.9-1.7 mg kg(-1) DM). Leaves-to-sediment ratios decreased as follows: Zn > Cu > Hg > Pb. According to Ti measurements, metal contamination by dry deposition was less than 1%. Mercury concentration in plant leaves was higher than European and French thresholds. Foliar absorption of volatile Hg was a major pathway for Hg contamination with a root absorption of Hg higher in rape than in cabbage and red fescue. Growth of each species increased Cu solubility. Zinc solubility was increased only in the presence of rape. The highest increase of Cu solubility was observed for red fescue whereas this species largely decreased Zn solubility. Dissolved organic carbon (DOC) measurements suggested that Cu solubilisation could result from organic matter or release of natural plant exudates. Dissolved inorganic carbon (DIC) measures suggested that the high Zn solubility in the presence of rape could originate from a generation of acidity in rape rhizosphere and a subsequent dissolution of calcium carbonates. Consequently, emission of volatile Hg from contaminated dredged sediments and also the potential increase of metal solubility by a vegetal cover of grass when used in phytostabilisation must be taken into account by decision makers.     

Analysis of computational problems expressing the overall uncertainties: photons, neutrons and electrons

In the frame of the EU Coordination Action CONRAD (coordinated network for radiation dosimetry), WP4 was dedicated to work on computational dosimetry with an action entitled 'Uncertainty assessment in computational dosimetry: an intercomparison of approaches'. Participants attempted one or more of eight problems. This paper presents the results from problems 4-8-dealing with the overall uncertainty budget estimate; a short overview of each problem is presented together with a discussion of the most significant results and conclusions. The scope of the problems discussed here are: the study of a (137)Cs calibration irradiator; the manganese bath technique; the iron sphere experiment using neutron time-of-flight technique; the energy response of a RADFET detector and finally the sensitivity and uncertainty analysis for the recoil-proton telescope discussed in the companion paper.     

Core/shell nanoparticles for multiple biological detection with enhanced sensitivity and kinetics

The paper shows the different methods to attach a molecule to detect streptavidin to a dielectric particle made of a rare-earth oxide core and a polysiloxane shell containing fluorescein. First, the detection of streptavidin binding on a biotinylated gold substrate can be achieved in three ways: the shift of the surface plasmon resonance of the substrate and the double luminescence (organic and inorganic) of the core/shell particle. Second, these detections are efficient even after elimination upon thermal annealing of all the undesired molecules that skew the assays. Finally, the particle that ballasts the protein enhances its binding kinetics and increases the localized surface plasmon resonance shift that detects the binding.     

Probing the structure of heterogeneous diluted materials by diffraction tomography

The advent of nanosciences calls for the development of local structural probes, in particular to characterize ill-ordered or heterogeneous materials. Furthermore, because materials properties are often related to their heterogeneity and the hierarchical arrangement of their structure, different structural probes covering a wide range of scales are required. X-ray diffraction is one of the prime structural methods but suffers from a relatively poor detection limit, whereas transmission electron analysis involves destructive sample preparation. Here we show the potential of coupling pencil-beam tomography with X-ray diffraction to examine unidentified phases in nanomaterials and polycrystalline materials. The demonstration is carried out on a high-pressure pellet containing several carbon phases and on a heterogeneous powder containing chalcedony and iron pigments. The present method enables a non-invasive structural refinement with a weight sensitivity of one part per thousand. It enables the extraction of the scattering patterns of amorphous and crystalline compounds with similar atomic densities and compositions. Furthermore, such a diffraction-tomography experiment can be carried out simultaneously with X-ray fluorescence, Compton and absorption tomographies, enabling a multimodal analysis of prime importance in materials science, chemistry, geology, environmental science, medical science, palaeontology and cultural heritage.     

Resonant gratings in planar Grandjean cholesteric composite liquid crystals

We propose to induce a two-dimensional (2D) periodic modulation structure into a planar Grandjean cholesteric liquid crystal (CLC) to demonstrate the intrinsic 2D photonic crystal properties of such materials. The structure combines a thin transmission grating and a Bragg reflective grating. One advantage of using CLC is the intrinsic high quality Bragg structure, which can be modulated by an electric field: shifting the wavelength band edge by changing the applied field. Another interesting property is the polarization dependence. The main difference between using CLC Bragg instead of a linear grating is the need to operate with a circularly polarized light, because the CLC modes are circular in such a regime. We present preliminary results obtained with what we believe to be the first switchable photonic CLC (PCLC) sample, made up of a polymer CLC gel.