Obstacle Avoidance Cell Discovery using mm-waves Directive Antennas in 5G Networks

With the advent of next-generation mobile devices, wireless networks must be upgraded to fill the gap between huge user data demands and scarce channel capacity. Mm-waves tech- nologies appear as the key-enabler for the future 5G networks design, exhibiting large bandwidth availability and high data rate. As counterpart, the small wave-length incurs in a harsh signal propagation that limits the transmission range. To overcome this limitation, array of antennas with a relatively high number of small elements are used to exploit beamforming techniques that greatly increase antenna directionality both at base station and user terminal. These very narrow beams are used during data transfer and tracking techniques dynamically adapt the direction according to terminal mobility. During cell discovery when initial synchronization must be acquired, however, directionality can delay the process since the best direction to point the beam is unknown. All space must be scanned using the tradeoff between beam width and transmission range. Some support to speed up the cell search process can come from the new architectures for 5G currently being investigated, where conventional wireless network and mm-waves technologies coexist. In these architecture a functional split between C-plane and U-plane allows to guarantee the continuous availability of a signaling channel through conventional wireless technologies with the opportunity to convey context information from users to network. In this paper, we investigate the use of position information provided by user terminals in order to improve the performance of the cell search process. We analyze mm-wave propagation environment and show how it is possible to take into account of position inaccuracy and reflected rays in presence of obstacle

Effects of biochar addition on long-term behaviour of concrete and mortar

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A \u201cnoisy\u201d electrical stimulation protocol favors muscle regeneration in vitro through release of endogenous ATP

An in vitro system of electrical stimulation was used to explore whether an innovative \u201cnoisy\u201d stimulation protocol derived from human electromyographic recordings (EMGstim)could promote muscle regeneration. EMGstim was delivered to cultured mouse myofibers isolated from Flexor Digitorum Brevis, preserving their satellite cells. In response to EMGstim, immunostaining for the myogenic regulatory factor myogenin, revealed an increased percentage of elongated myogenin-positive cells surrounding the myofibers. Conditioned medium collected from EMGstim-treated cell cultures, promoted satellite cells differentiation in unstimulated myofiber cell cultures, suggesting that extracellular soluble factors could mediate the process. Interestingly, the myogenic effect of EMGstim was mimicked by exogenously applied ATP (0.1 \u3bcM), reduced by the ATP diphosphohydrolase apyrase and prevented by blocking endogenous ATP release with carbenoxolone. In conclusion, our results show that \u201cnoisy\u201d electrical stimulations favor muscle progenitor cell differentiation most likely via the release of endogenous ATP from contracting myofibres. Our data also suggest that \u201cnoisy\u201d stimulation protocols could be potentially more efficient than regular stimulations to promote in vivo muscle regeneration after traumatic injury or in neuropathological diseases

Novel PBAT-Based Biocomposites Reinforced with Bioresorbable Phosphate Glass Microparticles

Biocomposites based on poly(butylene adipate terephthalate) (PBAT) and reinforced with micro-particles of inorganic biodegradable phosphate glass (PG) at 2, 10, and 40 wt% are prepared and characterized from a mechanical and morphological point of view. Scanning electron microscope (SEM) images show a good dispersion of the PG micro-grains, even at high concentrations, in the PBAT matrix, resulting in homogeneous composites. Tensile and dynamic-mechanical tests, respectively, indicate that Young's and storage moduli increase with PG concentration. The reinforcement of PBAT aims at modifying and tailoring the mechanical and viscoelastic properties of the material to expand its application field especially in the food and agricultural packaging sector, thanks to the similarity of PBAT performance with polyethylene

Tinnitus revival during COVID‑19 lockdown: how to deal with it?

To the Editor, The novel Coronavirus Disease, officially designated as COVID-19 by the WHO, is a serious issue for public health. To contain the COVID-19, the Italian Government stated on March 9th 2020 the prohibition of any movement throughout the national area unless for work/health reasons and the obligation to remain as much as possible inside one’s own home. With the start of the so-called “Phase Two” on May 4th 2020, circulation within the same region was allowed again, due to the progressive slowdown of the outbreak. Therefore, since lockdown measures were relaxed and access to the emergency room or ENT clinic became less worrying for patients, specialists of Otolaryngology Units in Bari (Italy) observed an increase in the amount of subjects complaining of the revival of intense tinnitus. We attempt in this letter to focus on patients affected by chronic subjective tinnitus, that already had a diagnosis and self-stabilized without a massive treatment. Research studies have reported tinnitus wide impact on quality of life of subjects experiencing it, involving their emotional state, concentration and sleep quality; at this regard, Tinnitus Handicap Inventory (THI) is a self-reported tool regularly used to quantify the grade of perceived handicap as slight (0–16), mild (18–36), moderate (38–56), severe (58–76) or catastrophic (78–100) on the basis of 25 questions [1]. During the past 2 weeks, we have collected data from 16 patients among our population of chronic sufferers: THI observed was moderate in 62.5% and severe in 18.75% of cases, catastrophic in 12.5% and mild in 6.25% of subjects. Interestingly, the grade of handicap resulted increased by one-level in 12 out of 16 patients (75%); in particular, THI shifted from mild to moderate in 9 patients and from moderate to severe in 3 patients. As shown in the literature, tinnitus generation, maintenance and recrudescence are still debated. A cortical reorganization secondary to sensory deprivation has been proposed as one on the most frequent cause of tinnitus [2]. The avoidance of silence and acoustic masking have been proposed as effective measures to overcome sensory deprivation and increase masking of the symptom [3]. It is reasonable to think that, during the lockdown, the absence of environmental masking sounds from everyday life may have enhanced the tinnitus perception. Furthermore, proneness to worry and incoming stress during pandemic could be included as further potential risk factors for tinnitus worsening. As proficiently reviewed in a recent work [4], some internet/smartphone-based applications provide in tinnitus patients adequate counseling and interactive information together with sound therapy. As brain networks implicated in adaptive responses to sound stimuli and to worry are shared in many cases, an early decrease of anxiety status may release neural resources crucial for tinnitus habituation/distress perception [5]. In general, interactive platforms have been widely implemented during lockdown period due to the forced lack of real personal and working relationships; since smart-working seems to be successful for future plans, the development of smart applications and mobile services in the health care field may be promising in terms of cost-effectiveness, tolerability and simplicity of use

Design of mechanical properties of poly(butylene-adipate-terephthalate) reinforced with Zein-TiO2 complex

The aim of this work was to realize and mechanically characterize composites based on poly(butyleneadipate-terephthalate) (PBAT) filled with micrometric particles of zein-TiO2 complex (ZTC) at different concentrations. Specimens model 1BA were obtained by injection molding and subjected to a uniaxial tensile test (UTT). The addition of the ZTC proved to have a reinforcing effect on the matrix, an increase in both Young’s modulus (E) and yield stress (σy) being observed. The mechanical properties were modeled applying Kerner’s and Pukánszky’s models, obtaining a good correspondence between theoretical experimental values and good matrix-filler interfacial interaction, respectively. Microscopical analysis revealed a good dispersion of the filler within the matrix

Solid-state phase transformations in thermally treated Ti-6Al-4V alloy fabricated via laser powder bed fusion

Laser Powder Bed Fusion (LPBF) technology was used to produce samples based on the Ti-6Al-4V alloy for biomedical applications. Solid-state phase transformations induced by thermal treatments were studied by neutron diffraction (ND), X-ray diffraction (XRD), scanning transmission electron microscopy (STEM) and energy-dispersive spectroscopy (EDS). Although, ND analysis is rather uncommon in such studies, this technique allowed evidencing the presence of retained \u3b2 in \u3b1' martensite of the as-produced (#AP) sample. The retained \u3b2 was not detectable byXRDanalysis, nor by STEM observations. Martensite contains a high number of defects, mainly dislocations, that anneal during the thermal treatment. Element diffusion and partitioning are the main mechanisms in the \u3b1 \u2194 \u3b2 transformation that causes lattice expansion during heating and determines the final shape and size of phases. The retained \u3b2 phase plays a key role in the \u3b1' \u2192 \u3b2 transformation kinetics

Towards 6G Evolution: Three Enhancements, Three Innovations, and Three Major Challenges

Over the past few decades, wireless communication has witnessed remarkable growth, experiencing several transformative changes. This article aims to provide a comprehensive overview of wireless communication technologies, from the foundations to the recent wireless advances. Specifically, we take a neutral look at the state-of-the-art technologies for 5G and the ongoing evolutions towards 6G, reviewing the recommendations of the International Mobile Communication vision for 2030 (IMT-2030). We first highlight specific features of IMT 2030, including three IMT-2020 extensions (URLLC+, eMBB+, and mMTC+) and three new innovations (Ubiquitous connectivity and integrating the new capabilities of sensing & AI with communication functionality). Then, we delve into three major challenges in implementing 6G, along with global standardization efforts. Besides, a proof of concept is provided by demonstrating terahertz (THz) signal transmission using Orbital Angular Momentum (OAM) multiplexing, which is one of the potential candidates for 6G and beyond. To inspire further potential research, we conclude by identifying research opportunities and future visions on IMT-2030 recommendations.Comment: 8 pages, 4 figures, 1 tabl

Neuronal Agrin Promotes Proliferation of Primary Human Myoblasts in an Age-Dependent Manner

Neuronal agrin, a heparan sulphate proteoglycan secreted by the -motor neurons, promotes the formation and maintenance of the neuromuscular junction by binding to Lrp4 and activating muscle-specific kinase (MuSK). Neuronal agrin also promotes myogenesis by enhancing differentiation and maturation of myotubes, but its effect on proliferating human myoblasts, which are often considered to be unresponsive to agrin, remains unclear. Using primary human myoblasts, we determined that neuronal agrin induced transient dephosphorylation of ERK1/2, while c-Abl, STAT3, and focal adhesion kinase were unresponsive. Gene silencing of Lrp4 and MuSK markedly reduced the BrdU incorporation, suggesting the functional importance of the Lrp4/MuSK complex for myoblast proliferation. Acute and chronic treatments with neuronal agrin increased the proliferation of human myoblasts in old donors, but they did not affect the proliferation of myoblasts in young donors. The C-terminal fragment of agrin which lacks the Lrp4-binding site and cannot activate MuSK had a similar age-dependent effect, indicating that the age-dependent signalling pathways activated by neuronal agrin involve the Lrp4/MuSK receptor complex as well as an Lrp4/MuSK-independent pathway which remained unknown. Collectively, our results highlight an age-dependent role for neuronal agrin in promoting the proliferation of human myoblasts

Effect of powder recycling in laser-based powder bed fusion of Ti-6Al-4V

Additive manufacturing (AM) has shown promise to process parts for end-use applications, however stringent requirements must be fulfilled in terms of reliability and predictability. The expensiveness of raw materials for AM, especially for metal-based Powder Bed Fusion (PBF), brings about the need for a careful recycling of powder, but the effect of powder reuse on both processing conditions and final part performance is still the focus of intensive research in the open literature. Although ASTM F2924-14 specifies the virgin-to-used powder ratio to be introduced to manufacture titanium-6aluminum-4vanadium (Ti-6Al-4V) components by PBF, a deeper understanding of the effect of powder recycling on the mechanical properties of finished parts is expected to foster a more efficient and safe reuse. The present contribution is therefore addressed to investigate the consequence of Ti- 6Al-4V powder recycling on the flowability, particle size distribution and morphology of the feedstock material as well as on the density and tensile performance of built parts. In order to quantify the recyclability of powders, a new "average usage time" (AUT) parameter is defined to account for both the real usage time of the powder and the virgin-to-used powder mixing ratio. The new parameter, whose applicability can be readily extended to any kind of feedstock powder, offers a significant contribution to achieve a more consistent and economical recycling of raw materials for PBF processing