SPIRAL: A novel biologically-inspired algorithm for gas/odor source localization in an indoor environment with no strong airflow

This work describes the design and experimental results of an algorithm, designed to localize a gas source in an indoor environment with no strong airflow by using an autonomous agent. This condition exacerbates the patchiness and intermittency of odor distribution, typical of turbulent flows in the presence of strong mean flows. Furthermore, no information about the wind can be used to detect the position of the source. In the approach proposed here, the robot moves along spirals. A spiral can be reset and a new one started, based on the information acquired about gas distribution. This enables the robot to get close to the ejecting source, without relying on airflow measurements. Results from experiments are also described and discussed, to assess the efficiency of the proposed method.     

ATP-mediated cytotoxicity in microglial cells

Microglial cells are known to express purinergic receptors for extracellular ATP of both the P2Y and P2X subtypes. Functional studies have shown that both primary mouse microglial cells and the N9 and N13 microglial cell lines express the pore-forming P2Z/P2X7 receptor. Here we identify the presence of this receptor in N9 and N13 cells with a specific polyclonal Ab and show that microglial cells expressing the P2Z/P2X7 receptor are exquisitively sensitive to ATP-mediated cytotoxicity while clones selected for the lack of this receptor are resistant. Transfection of HEK293 cells with P2X7 (but not P2X2) receptor cDNA confers susceptibility to ATP-mediated cytotoxicity. Morphological and biochemical analysis suggests that ATP-dependent cell death in microglial cells occurs by apoptosis. Finally, microglial cells release ATP via a non-lytic mechanism when activated by bacterial endotoxin, thus suggesting the operation of a purinergic autocrine/paracrine loop.     

Crystal structure of MTCP-1: implications for role of TCL-1 and MTCP-1 in T cell malignancies

Two related oncogenes, TCL-1 and MTCP-1, are overexpressed in T cell prolymphocytic leukemias as a result of chromosomal rearrangements that involve the translocation of one T cell receptor gene to either chromosome 14q32 or Xq28. The crystal structure of human recombinant MTCP-1 protein has been determined at 2.0 A resolution by using multiwavelength anomalous dispersion data from selenomethionine-enriched protein and refined to an R factor of 0.21. MTCP-1 folds into a compact eight-stranded beta barrel structure with a short helix between the fourth and fifth strands. The topology is unique. The structure of TCL-1 has been predicted by molecular modeling based on 40% amino acid sequence identity with MTCP-1. The identical residues are clustered inside the barrel and on the surface at one side of the barrel. The overall structure of MTCP-1 superficially resembles the structures of proteins in the lipocalin family and calycin superfamily. These proteins have diverse functions, including transport of retinol, fatty acids, chromophores, pheromones, synthesis of prostaglandin, immune modulation, and cell regulation. However, MTCP-1 differs in the topology of the beta strands. The structural similarity suggests that MTCP-1 and TCL-1 form a unique family of beta barrel proteins that is predicted to bind small hydrophobic ligands and function in cell regulation.     

ZnO nanowire arrays as substrates for cell proliferation and differentiation

In the latest years, the use of zinc oxide (ZnO) nanostructures has been proposed in different biomedical applications, however, to date, only a few contrasting results concerning their biocompatibility can be found in the literature. In particular, the application of the extraordinary piezoelectric properties of ZnO nanostructures has poorly been explored for the culture of electrically excitable cells, and, for this reason, systematic investigations of their interactions with these living systems appear to be necessary. In this paper, we report about adhesion, proliferation and differentiation of two mammalian cell lines (PC12, as model of neuronal cells, and H9c2, as model of muscle cells) over ZnO nanowire arrays. We demonstrate suitability of these arrays in sustaining cellular functions, and their potential in applications that range from tissue engineering to minimally invasive sensing and/or stimulation.     

Spatially modulated illumination microscopy allows axial distance resolution in the nanometer range

For an improved understanding of the structural basis of cellular mechanisms, it is highly desirable to develop methods for a detailed topological analysis of biological nanostructures and their dynamics in the interior of three-dimensionally conserved cells. We present a method of far-field laser fluorescence microscopy to measure relative axial positions of pointlike fluorescent targets and the distance between each target in the range of a few nanometers. The physical principle behind this approach can be extended to the determination of three-dimensional (3D) positions and 3D distances between any number of objects that can be discriminated owing to their spectral signature, thus allowing topological measurements so far regarded to be beyond the capabilities of light microscopy.     

Far-infrared laser measurement of the refractive index of polypropylene

The refractive index of polypropylene in the far infrared (FIR) is measured by means of a suitably modified laser of a FIR spectrometer. When thin polypropylene films of 12.7-microm nominal thickness are introduced in the optical cavity of a laser at the Brewster angle, the radiation ceases because of the change in the optical path of the laser beam. This change is measured from the displacement of one of the laser mirrors, which is necessary to restore the laser resonance. The refractive index of polypropylene is deduced from this measurement and from the film thickness, as obtained from an independent measurement based in pycnometry. The value obtained for the refractive index is 1.492(15) for the wavelengths between 118.834 and 251.140 microm, for a polypropylene film of 12.71(2)-microm thickness and 0.9049(7) g/cm3 density.     

A 3D Real‐Scale,Biomimetic, and Biohybrid Model of the Blood‐Brain Barrier Fabricated through Two‐Photon Lithography

The investigation of the crossing of exogenous substances through the blood‐brain barrier (BBB) is object of intensive research in biomedicine, and one of the main obstacles for reliable in vitro evaluations is represented by the difficulties at the base of developing realistic models of the barrier, which could resemble as most accurately as possible the in vivo environment. Here, for the first time, a 1:1 scale, biomimetic, and biohybrid BBB model is proposed. Microtubes inspired to the brain capillaries were fabricated through two‐photon lithography and used as scaffolds for the co‐culturing of endothelial‐like bEnd.3 and U87 glioblastoma cells. The constructs show the maturation of tight junctions, good performances in terms of hindering dextran diffusion through the barrier, and a satisfactory trans‐endothelial electrical resistance. Moreover, a mathematical model is developed, which assists in both the design of the 3D microfluidic chip and its characterization. Overall, these results show the effective formation of a bioinspired cellular barrier based on microtubes reproducing brain microcapillaries to scale. This system will be exploited as a realistic in vitro model for the investigation of BBB crossing of nanomaterials and drugs, envisaging therapeutic and diagnostic applications for several brain pathologies, including brain cancer.     

AML: a modeling language for designing adaptive web applications

Modern WWW methodologies focus on developing context-aware data delivery applications on the Web, but very few proposals provide a conceptual modeling of their adaptation specifications. In this paper, we present AML—Adaptation Modeling Language—to specify complex Adaptive Web Applications at the conceptual level. AML models the adaptation process by using a special workflow involving modeling primitives that execute elementary manipulations. The adaptation considers different and orthogonal components of the context and operates over the selection of the most suitable contents, the organization of the hypertext structure of the response, and the layout of the final pages. The language and its design process are fully implemented in a CASE tool, called FAWIS. Specifically, FAWIS is able to access a Web data source and automatically filter and adapt information delivery on the basis of the context of the client. The tool is able to manage heterogeneous contexts, is easy extensible to new coordinates of adaptation, and can integrate different adaptation requirements solving possible conflicts between them. It allows the designer to define the response that better satisfies the requirements of adaptation for a context.     

Facile Handling of 3D Two-Photon Polymerized Microstructures by Ultra-Conformable Freestanding Polymeric Membranes

Micro-nano-fabrication on objects with complex surfaces is essential for the development of technologies in the growing fields of flexible electronics and photonics. Various strategies are devised to extend the fabrication from conventional planar substrates to curved ones, however, significant challenges still exist, especially in the framework of 3D printing and additive manufacturing. In this study, a novel technique is presented to realize 3D micro-structures on arbitrary complex surfaces providing an extreme level of conformability. This method relies on the fabrication of micro-structures via two-photon polymerization on polymeric nano-membranes that can be efficiently transferred to a specific target. Ultra-thin polymeric films are exploited as the support to suspend and transfer the printed micro-structures on the predefined surface. The nanofilm can finally be easily removed, apart from the region underneath the printed elements where it serves as a few tens of nanometers adhesive. The repeatability and feasibility of the proposed process are investigated and shown to provide large flexibility of choice on the printed structures, materials used, transfer procedures, and targeted substrate geometries. By integration with standard fabrication processes, the described technique offers a great potential for the development of next-generation multidimensional/multi-material micro-nano-technologies.