Three months of Western diet induces small intestinal mucosa alteration in TLR KO mice

Several studies support the role of Western‐style diet (WD) in inflammatory bowel disease (IBD). Toll‐like receptors/NOD‐like receptors (TLRs/NLRs) are important to maintain a healthy epithelium as well as inducing inflammation. Given that dietary factors influence IBD development, that epithelial dysfunction is thought to be involved in initiating intestinal inflammation and that TLR‐NLR are involved in maintenance of the functionality of intestinal epithelium as well as in regulating inflammation, we decided to examine the role of TLR signals in the triggering events that lead to alteration of the small intestinal epithelium associated to consumption of WD. C57BL/6J mice deficient for TLR2, 4, 9, or NOD2 and wild‐type (WT) were fed a WD or a standard diet for 3 months. The effects of WD on small intestinal samples were evaluated by histological and immunohistochemical analysis. After 3 months, WD modifies the morphology and the organization of the small intestine in TLR9 KO mice compared with WT mice and the others TLRs. The most interesting change involved the expression of proliferative and differentiation markers of WNT signaling, Ki67 and FzD5. Mice deficient in TLR2, 4, and NOD2 have a significant reduction in the proliferative cell numbers but do not show any signs of histological alterations. Our results suggest that TLR9 is an important protective factor in intestinal epithelial homeostasis and provide new insights into an unrecognized role of TLR9 signaling in the small intestinal mucosa dysfunction associated with WD.     

Description of a propulsion unit used in guiding a walking machine by recognizing a three-point bordered path

A reconfigurable propulsion unit based on the Peaucellier-Lipkin mechanism has the ability to describe exact straight or curved paths depending on the selected ratio between the lengths of two of its links. The Peaucellier-Lipkin mechanism with one degree of freedom is transformed into a more sophisticated parallel kinematic chain by including four more degrees of freedom. The resulting propulsion unit is able to adapt its kinematic structure and reach instant centers of rotation, in accordance with the presence of three points that border a geometric path. A laser sensor mounted on the body of the machine detects each point. Once the machine has detected the exact location of the border of the road, it walks along a curve parallel to that border. Although the proposed research describes only one propulsion unit or leg, the methodology can be applied to all the legs of the walking machine. The novel 5-DOF leg is able to reach different centers of rotation, providing either the concave or convex arcs that satisfy the basic principle of displacement of walking machines.     

A Robust Design for Cellular Vehicles of Gold Nanorods for Multimodal Imaging

The pursuit of more selectivity in the delivery of plasmonic particles to tumors is critical before their penetration into clinical applications as the photoacoustic imaging and the photothermal ablation of cancer. As their direct infusion into the bloodstream remains problematic, due to a multitude of biological barriers, the development of alternative approaches is emerging as a new challenge. In this context, the recruitment of homologous tumor‐tropic cells that may serve as Trojan horses stands out as a fascinating possibility. Here, a novel model of gold nanorods is presented that feature a composite shell and undergo efficient and reproducible endocytic uptake from murine macrophages, which is fine‐tunable over a broad range of conditions. These cells preserve their viability and more than 90% of their innate chemotactic behavior in vitro, even with a cargo exceeding 200 000 particles per cell. In addition, we show that these vehicles are detectible by photoacoustic imaging down to concentrations in the order of 1% in whole blood and by clinical X‐ray computed tomography below 10%, which is within the typical fraction of a leukocytic infiltrate in a tumor microenvironment, and may even work as contrast agents for the photothermal ablation of cancer.     

Highly thermostable and crystalline poly(butylene adipate) bionanocomposites prepared by in situ polycondensation with organically modified Moroccan beidellite clay

Bionancomposites from bioplastics and nanoclays are of great interest for packaging, agricultural and other large‐volume and niche applications due to their enhanced physical, thermal, mechanical and processing characteristics compared to the parent polymer. In this study, the biodegradable polyester poly(butylene adipate) (PBA ) was synthesized by in situ polycondensation catalysed by titanium tetrabutoxide in the presence of the natural Moroccan clay beidellite (BDT ). Optimization of the nanoclay exfoliation in the bionanocomposite was achieved by cation exchange of BDT with cetyltrimethylammonium bromide (CTA ) and by selecting the most effective among a range of organically modified x CTA‐BDT (x = CTA/BDT equivalent feed ratio). Fourier transform infrared and ¹H NMR spectral and size exclusion chromatographic analyses confirmed the effectiveness of the in situ polymerization, yielding structurally regular PBA with narrow molecular weight dispersity and 7750 < < 30 360 g mol^?1, depending on the organoclay load. X‐ray diffraction and transmission electron microscopy analyses showed best clay dispersion and homogeneous distribution at 2 wt% 3CTA‐BDT. From thermogravimetric analysis and differential scanning calorimetry results the thermal stability of PBA is greatly improved even at 1 wt% 3CTA‐BDT, its glass transition temperature is nearly unaffected while crystallinity is increased by the organoclay nucleating action. These results, along with a bionanocomposite hydrophilicity only moderately higher than that of PBA, make this preparation approach particularly promising. © 2017 Society of Chemical Industry     

High‐Temperature Structural Evolution of the Disordered LiMn1.5Ni0.5O4

In this work, we present our recent results about the changes induced on a crystalline bulk LiMn_1.5Ni_0.5O₄ disordered cubic spinel phase by thermal treatments carried out under different back atmospheres (vacuum and air). Our aim is to describe the structural changes induced by temperature in various conditions both on the long range (by means of XRD) and on the short range around Mn/Ni metal sites (by means of EXAFS) and to investigate the reversible oxygen loss and adsorption upon heating and cooling, respectively. In summary, the LiMn_1.5Ni_0.5O₄ phase suffers large structural modifications above 650°C both under vacuum and air. These alterations are closely related to the occurrence of large oxygen vacancies in the anionic sublattice due to spontaneous oxygen loss via the gas phase. Apparently, local and long‐range distortions from the pristine disordered cubic spinel structure are completely reversible in air upon cooling from high temperature, whereas under vacuum, the structural alterations are permanent.     

The application of heat‐deproteinization to the morphological study of cortical bone: A contribution to the knowledge of the osteonal structure

Observation of heat‐deproteinized cortical bone specimens in incident light enabled the high definition documentation of the osteonal pattern of diaphyseal Haversian bone. This prompted a study to compare these images with those revealed by polarized light microscopy, carried out either on decalcified or thin, undecalcified, resin‐embedded sections. Different bone processing methods can reveal structural aspects of the intercellular matrix, depending on the light diffraction mode: birefringency in decalcified sections can be ascribed to the collagen fibrils orientation alone; in undecalcified sections, to both the ordered layout of collagen and the inorganic phase; in the heat‐deproteinized samples, exclusively to the hydroxyapatite crystals aggregation mode. The elemental chemical analysis documented low content of carbon and hydrogen, no detectable levels of nitrogen and significantly higher content of calcium and phosphorus in heat‐deproteinized samples, as compared with dehydrated controls. In both samples, the X‐ray diffraction (XRD) pattern did not show any significant difference in pattern of hydroxyapatite, with no peaks of any possible decomposition phases. Scanning electron microscopic (SEM) morphology of heat‐deproteinized samples could be documented with the fracturing technique facilitated by the bone brittleness. The structure of crystal aggregates, oriented in parallel and with marks of time periods, was documented. Comparative study of deproteinized and undecalcified samples showed that the matrix inorganic phase did not undergo a coarse grain thermal conversion until it reached 500°C, maintaining the original crystals structure and orientation. Incident light stereomicroscopy, combined with SEM analysis of deproteinized bone fractured surfaces, is a new enforceable technique which can be used in morphometric studies to improve the understanding of the osteonal dynamics. Microsc. Res. Tech. 79:691–699, 2016. © 2016 Wiley Periodicals, Inc.     

Enhancing post-classification change detection through morphological post-processing – a sensitivity analysis

Monitoring land-cover change is often done by simple overlay of two classified maps from different dates. However, such analysis tends to overestimate the rate of change. Main error sources are the mis-registration between classified maps and their thematic accuracies. This study proposes a change detection method with morphological post-processing to improve change detection accuracy in comparison with traditional post-classification by taking into account these error sources. The method is developed for binary maps and is based on standard morphological procedures that are generally integrated in common spatial processing or free software. A detailed sensitivity analysis of this method based on simulated data sets of different landscape characteristics and error levels demonstrated the potential improvement. The degree of improvement in change detection accuracy mainly depended on the error type and level and the fragmentation of the landscape. In particular, location error effects on change detection were strongly reduced independent of class proportion. Up to 60% improvement in user's accuracy of change could be achieved for maps with location error and characterized by fragmented landscapes. Coping with classification errors was shown to be more challenging. A user-friendly reference table summarizes the potential improvement through the proposed methods for various landscape characteristics and error sources.