Detecting Localized Plastic Strain by a Scanning Collinear Wave Mixing Method

When the frequencies of a pair of collinear shear and longitudinal waves satisfy the resonant condition, mixing of these two primary waves generates a third, resonant shear wave that propagates in the direction opposite to the propagating direction of the primary shear wave. In this study, experiments were conducted to demonstrate that the acoustic nonlinearity parameter at the location of the mixing zone can be obtained by measuring the resonant shear wave. Since the location of the mixing zone can be controlled by adjusting the trigger time of the transducers that generate the primary waves, this collinear wave mixing technique enables the scanning of a bar sample to measure the distribution of acoustic nonlinearity along the bar. To demonstrate this scanning capability, bar samples with non-uniform acoustic nonlinearity parameters were fabricated by inducing localized plastic deformation at known locations. Scanning collinear wave mixing tests conducted on such bar samples clearly identified the locations of the plastic zone. These results show that collinear wave mixing is a promising method for scanning the test sample to map out the distribution of localized plastic deformation.     

Mass Spectrometry,Ion Mobility Separation and Molecular Modelling: A Powerful Combination for the Structural Characterisation of Substituted Cyclodextrins Mixtures

When working on the synthesis of substituted cyclodextrins (CDs), the main challenge remains the analysis of the reaction media content. Our objective in this study was to fully characterise a complex isomers mixture of Lipidyl-βCDs (LipβCD) obtained with a degree of substitution 1 (DS = 1) from a one-step synthesis pathway. The benefit of tandem mass spectrometry (MS/MS) and ion mobility separation hyphenated with mass spectrometry (IM-MS) was investigated. The MS/MS fragment ion‘s relative intensities were analysed by principal component analysis (PCA) to discriminate isomers. The arrival time distribution (ATD) of each isomer was recorded using a travelling wave ion mobility (TWIM) cell allowing the determination of their respective experimental collision cross section (CCS_exp). The comparison with the predicted theoretical CCS (CCS_th) obtained from theoretical calculations propose a regioisomer assignment according to the βCD hydroxyl position (2, 3, or 6) involved in the reaction. These results were validated by extensive NMR structural analyses of pure isomers combined with molecular dynamics simulations. This innovative approach seems to be a promising tool to elucidate complex isomer mixtures such as substituted cyclodextrin derivatives.     

Development of Anti-LRRC15 Small Fragments for Imaging Purposes Using a Phage-Display ScFv Approach

The human leucine-rich repeat-containing protein 15 (LRRC15) is a membrane protein identified as a marker of CAF (cancer-associated fibroblast) cells whose overexpression is positively correlated with cancer grade and outcome. Nuclear molecular imaging (i.e., SPECT and PET) to track LRRC15 expression could be very useful in guiding further therapeutic strategies. In this study, we developed an ScFv mouse phage-display library to obtain small fragment antibodies against human LRRC15 for molecular imaging purposes. Mice were immunized with recombinant human LRRC15 (hLRRC15), and lymph node cells were harvested for ScFv (single-chain variable fragment) phage-display analysis. The built library was used for panning on cell lines with constitutive or induced expression after transfection. The choice of best candidates was performed by screening various other cell lines, using flow cytometry. The selected candidates were reformatted into Cys-ScFv or Cys-diabody by addition of cysteine, and cloned in mammalian expression vectors to obtain batches of small fragments that were further used in site-specific radiolabeling tests. The obtained library was 1.2 × 10⁷ cfu/µg with an insertion rate >95%. The two panning rounds performed on cells permittedenrichment of 2 × 10⁻³. Screening with flow cytometry allowed us to identify 28 specific hLRRC15 candidates. Among these, two also recognized murine LRCC15 and were reformatted into Cys-ScFv and Cys-diabody. They were expressed transiently in a mammalian system to obtain 1.0 to 4.5 mg of Cys fragments ready for bioconjugation and radiolabeling. Thus, in this paper, we demonstrate the relevance of the phage-display ScFv library approach for the fast-track development of small antibodies for imaging and/or immunotherapy purposes.     

A systematic review of the potential hurdles of interoperability to the emergency services in major incidents: recommendations for solutions and alternatives

This study presents a narrative synthesis of a systematic literature review relating to multi-agency interoperability and major incident decision-making in high risk, high stake environments. The review methodology includes the identification of relevant studies, a critical appraisal of the concepts inherent in the main review question and a narrative synthesis of the central themes that relate to the study as a whole. The review firstly outlines what, currently, appear to be the perceived defining features of successful interoperability by using the SAFE-T phase model of major incident decision-making. It then considers whether these defining features are realistically achievable in major incident practice. Findings suggest that the current definition of an interoperable network is too demanding for the inherent complexity and dynamic nature of the major incident task environment. Individual teams tend to focus on agency-specific behaviour, as opposed to coordinated multi-team functioning, and so collective interoperability is not achieved. Inevitably, this reduces the ability to perform collaborative behaviours, including decision-making and action implementation. The paper concludes that aiming for the current conceptualisation of interoperability along a hierarchical command structure may actually inhibit effective decision-making. Instead, multi-agency systems would do better to work towards an improved understanding of a non-hierarchical and decentralised yet interoperable major incident management network. Recommendations include the need to relate theory and practice in the development of multi-agency decision-making via simulation-based training and to deepen our understanding of interoperability to prevent inertia in high risk, high stake major incident environments.     

Vertical distribution of fauna in the bed sediment of three running water sites: Influence of physical and trophic factors

Relationships between invertebrates, substrate characteristics and trophic factors were investigated, with special emphasis on the hyporheic habitat, in order to characterize the functioning of different running waters ecosystems. Three contrasting study sites were chosen in catchments exhibiting different features: (1) a meandering reach of the Loire River in its alluvial floodplain, upstream of the ‘Bec d'Allier’; (2) a reach of the Galaure with a fairly developed riparian corridor, a small sinuous foothill river; and (3) a braided reach of the Drac, an alpine torrential stream. Each site was sampled once using the freezing-core technique with previous electro-positioning of the invertebrates. In each site, four 60 cm cores were extracted, each one from different morphodynamic units. In the Loire and Galaure rivers, most invertebrates are found in the first 15 cm of the sediment, with the exception of some particular taxa or morphodynamic units (riffle head). Conversely, in the Drac lotic units, maximum density of invertebrates occurs between 15 and 30 cm and more than 75 per cent of all organisms are found at a depth > 15 cm. The vertical distribution of organisms does not follow a uniform pattern in different streams. In the substrate, the vertical distribution of macroinvertebrates is very closely related to porosity in contrast with trophic parameters that always decrease with depth. The porosity is negatively correlated with the percentage of sand in the sediment and seems to be important in determining the vertical distribution of fauna, and should be integrated in a functional typology of running waters. The trophic parameters and the structure of invertebrate community with its dominant feeding groups allow discrimination of the different sites.     

Magnetic Nanocrystals Aligned on Mesoscopic Scale: Collective Properties and Their Use

Magnetic nanocrystals organized in chain-like structures behave as nanowires with a shape anisotropy induced by the structuration of the sample. This is valid for various types of magnetic nanomaterials. Furthermore, the coating of nanocrystals plays a major role in the mesoscopic structure of the film. γ-Fe₂O₃ nanocrystals are used as a mask to reproduce the mesoscopic structure on a silicon wafer.     

River, reservoir and lake sediment contamination by heavy metals downstream from urban areas of Switzerland

This paper quantifies sediment contamination by heavy metals in four reservoirs and one lake located downstream from major urban areas in Switzerland. The waterbodies include the Wettingen Reservoir (located on the Limmat River downstream from Zürich), the Klingnau Reservoir (on the lower Aare River), the Wohlen Reservoir (downstream from Berne), the Verbois Reservoir (downstream from Geneva) and Vidy Bay (Lake Geneva, city of Lausanne). For all sediment cores and contaminants, a trend is observed from high contaminant values in the lower part of the cores, decreasing to lower concentrations in the upper part of the cores. However, for each site and each element, specific features are recognized. Applying the criteria of the Swiss ordinance on soil protection, all sediment cores must be classified as contaminated by one or more contaminants and at variable levels. From these data, it is concluded that: reservoirs and lakes located downstream from major urban centres in Switzerland have accumulated significant volumes of contaminated sediments in the past, representing the largest, but not the most intensely, contaminated sites on a national scale; the main environmental risk is remobilization of the contaminants and their return to the food chain, particularly by infiltration into the groundwater; and although the processes of remobilization are identified, the conditions of occurrence and the amplitude of the processes are still poorly known. Different options of reservoir and lake sediment management also are discussed and further research topics defined.     

A low cost,one-piece nitrogen burst processing rack for 3¼× 4 inches and 4×5 inches TEM and SEM negatives

A processing rack designed with a built-in nitrogen burst plenum to accommodate 3¼ × 4 in. and 4 × 5 in. negative can be inexpensively constructed from plexiglass.     

Science,technology and China's four modernizations

The crux of the four modernizations is the mastery of modern science and technology. Without them it is impossible to build modern agriculture, modern industry, or national defense.     

Hydrous oxide formation on gold in base under potential cycling conditions

The formation of hydrous oxide films on gold in base under potential cycling conditions was investigated and found to be less inhibited than the same type of reaction observed when gold is strongly anodized at high potentials under d.c. conditions at high pH. The overall behaviour on cycling is quite similar to that observed with other metals, e.g. platinum. The importance of the lower limit, for instance, again appears to be related to the need under film thickening conditions to significantly reduce the compact oxide layer formed on the metal surface during the anodic sweep. It was noted that the earlier duplex model for this type of system, i.e. an inner compact and an outer dispersed oxide layer, is not always valid. Under certain conditions about six distinct peaks (suggesting six different states of gold oxide hydration, dispersion or polymerization) were observed in cathodic sweeps recorded for the reduction of thick films grown on gold under potential cycling conditions in base.