Novel Algorithm for Radon Real-Time Measurements with a Pixelated Detector

Nowadays, radon gas exposure is considered one of the main health concerns for the population because, by carrying about half the total dose due to environmental radioactivity, it is the second cause of lung cancer after smoking. Due to a relatively long half-life of 3.82 days, the chemical inertia and since its parent Ra-226 is largely diffuse on the earthrgb]0,0,1’s crust and especially in the building materials, radon can diffuse and potentially saturate human habitats, with a concentration that can suddenly change during the 24 h day depending on temperature, pressure, and relative humidity. For such reasons, `real-time’ measurements performed by an active detector, possibly of small dimensions and a handy configuration, can play an important role in evaluating the risk and taking the appropriate countermeasures to mitigate it. In this work, a novel algorithm for pattern recognition was developed to exploit the potentialities of silicon active detectors with a pixel matrix structure to measure radon through the α emission, in a simple measurement configuration, where the device is placed directly in air with no holder, no collection filter or electrostatic field to drift the radon progenies towards the detector active area. This particular measurement configuration (dubbed as bare) requires an α/β-discrimination method that is not based on spectroscopic analysis: as the gas surrounds the detector the α particles are emitted at different distances from it, so they lose variable energy amount in air depending on the traveled path-length which implies a variable deposited energy in the active area. The pixels matrix structure allows overcoming this issue because the interaction of α, β and γ particles generate in the active area of the detector clusters (group of pixels where a signal is read) of different shape and energy dispersion. The novel algorithm that exploits such a phenomenon was developed using a pixelated silicon detector of the TimePix family with a compact design. An α(Am-241) and a β(Sr-90) source were used to calibrate the algorithm and to evaluate its performances in terms of β rejection capability and α recognition efficiency. Successively, the detector was exposed to different radon concentrations at the ENEA-INMRI radon facility in `bare’ configuration, in order to check the linearity of the device response over a radon concentration range. The results for this technique are presented and discussed, highlighting the potential applications especially the possibility to exploit small and handy detectors to perform radon active measurements in the simplest configuration.

Application of Recursive Algorithm on Shamir's Scheme Reconstruction for Cheating Detection and Identification

Information data protection is necessary to ward off and overcome various fraud attacks that may be encountered. A secret sharing scheme that implements cryptographic methods intends to maintain the security of confidential data by a group of trusted parties is the answer. In this paper, we choose the application of recursive algorithm on Shamir-based linear scheme as the primary method. In the secret reconstruction stage and since the beginning of the share distribution stage, these algorithms have been integrated by relying on a detection parameter to ensure that the secret value sought is valid. Although the obtained scheme will be much simpler because it utilizes the Vandermonde matrix structure, the security aspect of this scheme is not reduced. Indeed, it is supported by two detection parameters formulated from a recursive algorithm to detect cheating and identify the cheater(s). Therefore, this scheme is guaranteed to be unconditionally secure and has a high time efficiency (polynomial running time).

A transient apical extracellular matrix relays cytoskeletal patterns to shape permanent acellular ridges on the surface of adult C. elegans

Apical extracellular matrices can form protruding structures such as denticles, ridges, scales, or teeth on the surfaces of epithelia. The mechanisms that shape these structures remain poorly understood. Here, we show how the actin cytoskeleton and a provisional matrix work together to sculpt acellular longitudinal alae ridges in the cuticle of adult C. elegans. Transient actomyosin-dependent constriction of the underlying lateral epidermis accompanies deposition of the provisional matrix at the earliest stages of alae formation. Actin is required to pattern the provisional matrix into longitudinal bands that are initially offset from the pattern of longitudinal actin filaments. These bands appear ultrastructurally as alternating regions of adhesion and separation within laminated provisional matrix layers. The provisional matrix is required to establish these demarcated zones of adhesion and separation, which ultimately give rise to alae ridges and their intervening valleys, respectively. Provisional matrix proteins shape the alae ridges and valleys but are not present within the final structure. We propose a morphogenetic mechanism wherein cortical actin patterns are relayed mechanically to the laminated provisional matrix to set up distinct zones of matrix layer separation and accretion that shape a permanent and acellular matrix structure.

Designing Natural Polymer-Based Capsules and Spheres for Biomedical Applications—A Review

Natural polymers, such as polysaccharides and polypeptides, are potential candidates to serve as carriers of biomedical cargo. Natural polymer-based carriers, having a core–shell structural configuration, offer ample scope for introducing multifunctional capabilities and enable the simultaneous encapsulation of cargo materials of different physical and chemical properties for their targeted delivery and sustained and stimuli-responsive release. On the other hand, carriers with a porous matrix structure offer larger surface area and lower density, in order to serve as potential platforms for cell culture and tissue regeneration. This review explores the designing of micro- and nano-metric core–shell capsules and porous spheres, based on various functions. Synthesis approaches, mechanisms of formation, general- and function-specific characteristics, challenges, and future perspectives are discussed. Recent advances in protein-based carriers with a porous matrix structure and different core–shell configurations are also presented in detail.

Prenatal diagnosis of primary congenital glaucoma and histopathological features in a fetal globe with cytochrome p4501B1 mutations

Background/Objectives This study aims to report the developmental and histopathological features of ocular tissues from an electively aborted human fetus with mutations in cytochrome p4501B1, and thus predisposed to primary congenital glaucoma in comparison to an age-matched healthy fetal globe. Subjects/Methods Both eyes of two 17-week gestational aged fetuses, the first with CYP1B1 mutations and the second as healthy control fetus, were studied. Hematoxylin and eosin, Periodic acid–Schiff, Gomori’s trichrome, and Verhoeff–Van Gieson staining protocols in addition to immunohistochemistry staining using anti-cytochrome p4501B1, anti-fibrillin-1, and anti-4-hydroxy-2-nonenal antibodies, as primary antibodies, were performed to assess the effect of the mutations on tissue development, cytochrome p4501B1 protein expression, extracellular matrix structure, and oxidative stress in the developing fetus eye. Quantitative analyses were performed using ImageJ software. Student’s t-test was used for statistical analysis and P-values <0.05 were considered as significant. Results Delayed development in ocular tissues, decreased expression of cytochrome p4501B1 protein, irregular extracellular matrix structure, and increased oxidative stress biomarker were evident in the ocular tissues of the fetus with cytochrome p4501B1 mutations as compared to a normal globe from an age-matched fetus. Conclusion To the best of our knowledge, this is the first report of prenatal diagnosis of primary congenital glaucoma. We also describe histopathological changes in the primary congenital glaucoma-affected globes revealing the effect of cytochrome p4501B1 deficiency on ocular tissues during early fetal development contributing to the glaucoma phenotype.

PREDICTIVE MATEHMATICAL MODEL FOR ABSORBANT SUBSTRATE ACHIEVEMENT, THROUGH ELECTROSPINNING PROCESS

The new generations of wound dressings aim to create an optimal environment that allows epithelial cells to move easily in order to support regeneration. Such optimal conditions include a humid environment around the wound bed, efficient oxygen circulation to help regenerate cells and tissues, and low bacterial contamination. Composite matrices have several layers and can be used as primary or secondary dressings. Most composite dressings have three layers, respectively a semi-adherent or non-adherent layer, an absorbent layer, and a bacterial barrier layer. A method to obtaining these materials, which can be assimilated to layerby- layer deposition, or which can be operated in this regime, is represented by electrospinning. However, the deposition technique by electrospinning on textile surfaces (fabrics or nonwovens) raises some problems related to the electrostatic behaviour of textile fibres with dielectric properties. In this case, the characteristics of the jet are affected directly proportional with the thickness of the textile material, resulting in defects of nano- or micro-fibrillar deposition, such as unevenness and/or sputter (formation of drops, which are deposited in mixture with electro spun fibres). The article presents a mathematical model that predicts the diameter of the fibres in the composition of the absorbent layer of the multilayer matrix structure for the treatment of burns or gunshot wounds, taking into account the nonlinear relationships between the parameters explained above and specific theories of electrodynamics for thin profiles (for instance, those used in aeronautics) for the prediction of the behaviour of the electrospinning jet.

The improvement of mechanical properties of conventional concretes using carbon nanoparticles using molecular dynamics simulation

In the present study, the improvement of mechanical properties of conventional concretes using carbon nanoparticles is investigated. More precisely, carbon nanotubes are added to a pristine concrete matrix, and the mechanical properties of the resulting structure are investigated using the molecular dynamics (MD) method. Some parameters such as the mechanical behavior of the concrete matrix structure, the validation of the computational method, and the mechanical behavior of the concrete matrix structure with carbon nanotube are also examined. Also, physical quantities such as a stress–strain diagram, Poisson's coefficient, Young's modulus, and final strength are calculated and reported for atomic samples under external tension. From a numerical point of view, the quantities of Young's modulus and final strength are converged to 35 GPa and 35.38 MPa after the completion of computer simulations. This indicates the appropriate effect of carbon nanotubes in improving the mechanical behavior of concrete and the efficiency of molecular dynamics method in expressing the mechanical behavior of atomic structures such as concrete, carbon nanotubes and composite structures derived from raw materials is expressed that can be considered in industrial and construction cases.