A Hydrogel Platform that Incorporates Laminin Isoforms for Efficient Presentation of Growth Factors – Neural Growth and Osteogenesis

Laminins (LMs) are important structural proteins of the extracellular matrix (ECM). The abundance of every LM isoform is tissue-dependent, suggesting that LM has tissue-specific roles. LM binds growth factors (GFs), which are powerful cytokines widely used in tissue engineering due to their ability to control stem cell differentiation. Currently, the most commonly used ECM mimetic material in vitro is Matrigel, a matrix of undefined composition containing LM and various GFs, but subjected to batch variability and lacking control of physicochemical properties. Inspired by Matrigel, a new and completely defined hydrogel platform based on hybrid LM-poly(ethylene glycol) (PEG) hydrogels with controllable stiffness (1–25 kPa) and degradability is proposed. Different LM isoforms are used to bind and efficiently display GFs (here, bone morphogenetic protein (BMP-2) and beta-nerve growth factor (β-NGF)), enabling their solid-phase presentation at ultralow doses to specifically target a range of tissues. The potential of this platform to trigger stem cell differentiation toward osteogenic lineages and stimulate neural cells growth in 3D, is demonstrated. These hydrogels enable 3D, synthetic, defined composition, and reproducible cell culture microenvironments reflecting the complexity of the native ECM, where GFs in combination with LM isoforms yield the full diversity of cellular processes.     

A SiGe BiCMOS 24-GHz receiver front-end for automotive short-range radar

This paper presents a fully integrated SiGe BiCMOS 24-GHz receiver front-end implemented for a ultra-wideband automotive short-range radar sensor. The circuit consists of a homodyne I/Q down-converter and a 24-GHz synthesizer. The receiver front-end is able to achieve a power conversion gain as high as 30 dB and a 6-dB noise figure, while preserving high linearity performance thanks to a 1-bit gain control. The frequency synthesizer, which also includes an on-chip loop filter, guarantees a phase noise of −104 dBc/Hz at 1-MHz offset from the 24.125-GHz carrier and a 4.7-GHz tuning range from 20.4 to 25.1 GHz.     

Low-voltage nanopower clock generator for RFID applications

The design of an on-chip RC-based oscillator, implemented in a standard BiCMOS process, without any external component, is presented. The proposed oscillator provides a clock signal at a frequency of 50 kHz with a temperature coefficient smaller than 0.3%/^°C over a temperature range from 0 to , without any external trimming. The proposed oscillator operates with a supply voltage of 0.8 V and has a power consumption of at room temperature. The chip area is .     

Wireless LANs Systems: An Advanced Resource Assignement Algorithm

The paper describes the design and simulation of a radio modem architecture, which provides wireless access to Internet in a single-hop, ad hoc network.The main emphasis is on the Medium Access Control (MAC) and Dynamic Link Control (DLC) layer’s design, and in particular on the adopted innovative scheduling algorithm, which has been developed to satisfy the system requirements of the WIND-FLEX radio modem. The algorithm is presented and compared to the Earliest Deadline First (EDF) solution.Several software simulation tests have been executed on the network, to test the performance of the system, in order to verify the capability of the scheduler algorithm to satisfy the expected requirements and the efficiency of the implemented solutions. Giuseppe Razzano was born in Roma, Italy, in 1974. He has graduated in Electronic Engineering “summa cum laude” and has received PhD in Communication Systems and Computer Science, in 2004 from University of Rome “La Sapienza”. From 2000 to 2001 he worked as research assistant at VTT electronics, in Finland. From 2004 to 2005 he worked as senior researcher at Forschungzentrum Telekommunikation Wien (Telecommunication Research Centre Vienna) in Austria. Currently, he works as System Engineer for Vitrociset S.p.A., working in a project funded by European Space Agency (ESA), for the development of a new generation space launcher vehicle (VEGA). In the past years, he worked in several projects funded by EC within the IST (Information Societies Technology) program, being also involved in projects in collaboration with Italian companies. His research is focused on resource management algorithms for wireless LANs and cellular networks. He is also interested in object-oriented programming and development methodologies. In these fields, he is author of several papers published in international journals and conferences. Francesco Delli Priscoli was born in Rome in 1962. He graduated in Electronic Engineering “summa cum laude” from the University of Rome “La Sapienza” in 1986. He received the Ph.D. in system engineering from the University of Rome “La Sapienza” in 1991. From 1986 to 1991 he worked in the “Studies and Experimentation” Department of Telespazio (Rome). Since 1991 he is working for the University of Rome “La Sapienza” where, at present, he is “Full Professor” and holds the courses “Automatic Controls”, “System Theory” and “Network Control and Management I and II”. In the framework of his activity, he researches in the nonlinear control theory and in the area of control-based resource management procedures for the third and forth generation of mobile systems. He is the author of about 150 technical papers on the above topics appeared on major international reviews (about 50) and conferences (about 100). In 2000 he has been scientific consultant for the Italian Council of Ministers in the framework of the auction for the assignment of the Italian Universal Mobile Telecommunication System (UMTS) licensees. He is an associate editor of Control Engineering Practice and a member of the IFAC Technical Committee on “Networked Systems”. He is/has been scientific responsible, for the University of Rome “La Sapienza”, of 17 projects financed by the European Union (fourth, fifth and sixth framework programmes) or by the European Space Agency (ESA), dealing with resource management for UMTS and broadband terrestrial and satellite wireless systems. He is also a project evaluator for the European Commission. Roberto Cusani received the “laurea” degree in Electronic Engineering (cum laude) and the Ph.D. in Communication Systems and Computer Science from the University of Rome “La Sapienza”. From 1986 to 1990 he was research engineer at the University of Rome “Tor Vergata”, teaching Digital Signal Processing. In 1991 he joined the University of Rome “La Sapienza” as Associate Professor of Signal Theory. In 2000 he becomes Full Professor and teaches Information Theory and Coding, and Mobile Communications. His former research activities concern transmission and coding of signals and images, with emphasis on random processes, spectral estimation and image coding. Since 1992 he focused his activities in the field of the digital communication systems, with emphasis on channel equalisation and coding for HF and radio-mobile (GSM) links, on the design of CDMA receivers for UMTS and, in general, on the use of digital techniques within telecommunication equipments. More recently his interests also includes the study of MAC (Multiple Access Control) protocols with application to wireless area networks (WLANs), reconfigurable ad-hoc networks and satellite links. He is author of more than 100 publications in international journals and conferences, of the text-book “Teoria dei Segnali” and of five patents regarding telecommunication applications. He was involved in many research programs, both national and international, and in projects with the industrie.     

Study on Planar Whispering Gallery Dielectric Resonators. I. General Properties

Several basic properties of homogeneous planar Whispering Gallery dielectric resonators are investigated through a general approach. In particular the values for the minimum and maximum allowed radius, defined by irradiation and dielectric losses, respectively, are obtained in terms of the complex dielectric constant of the involved media. The same approach is employed in the analysis of the limit allowed frequencies of a fixed family of mode, leading to the definition of the “ideal” frequency band. The role of the transverse mode is then discussed, and the “effective” frequency band is introduced and determined both in simple disc and circular ring resonators. The extension of the effective band is limited at least by a factor 3, in terms of decades, in comparison to the extension of the ideal one; this limitation, due to the presence of transverse modes, can be overcome using suitable designed nonhomogeneous resonators, as discussed in a following companion paper.     

Open-Ended Waveguide Measurement and Numerical Simulation of the Reflectivity of Petri Dish Supported Skin Cell Monolayers in the mm-wave Range

Open-ended waveguide reflectometry is a promising tool for permittivity and other material properties calculation at mm-waves (30–300 GHz). Measurement of the reflection coefficient does not require sample manipulation, allowing in vivo and in vitro non destructive studies on cells. Here we used this technique for measuring the power reflection coefficient (reflectivity) of water and Petri dish supported human skin melanoma and keratinocyte cell cultures, in the 53–72 GHz frequency range. The dependence of the reflectivity on polystyrene or glass thickness of the Petri base plate and on the cell layer thickness was analyzed. Permittivity data were then easily retrieved by using a plane wave-dominant mode approach for formulating the reflectivity at the aperture of the flange-mounted open-ended rectangular waveguide probe. Limits and validity of such an approximate approach were analyzed and compared with full-wave near field formulations for which magnitude and phase of the reflection coefficient must be measured and solved using complicated systems of integral equations and extensive numerical calculation. Finally, Petri dish reflectivity measured by the open-ended waveguide method was compared with that numerically simulated under far-field exposure conditions used in a large number of in vitro studies. Such an analysis showed that, under certain conditions, open-ended reflectivity values approach the far field ones.     

Fabrication and Electrochemical Properties of Epitaxial Samarium‐Doped Ceria Films on SrTiO3‐Buffered MgO Substrates

Thin films of samarium‐oxide‐doped (20 mol%) ceria (SDC) are grown by pulsed‐laser deposition (PLD) on (001) MgO single‐crystal substrates. SrTiO₃ (STO) prepared by PLD is used as a buffer layer on the MgO substrates to enable epitaxial growth of the fluorite‐structured SDC film; the STO layer provides a proper crystalline match between SDC and MgO, resulting in highly crystalline, epitaxial SDC films grown in the (001) orientation. Film conductivity is evaluated by electrochemical impedance spectroscopy measurements, which are performed at various temperatures (400–775 °C) in a wide range of oxygen partial pressure (pO₂) values (10^?25?1 atm) in order to separate ionic and electronic conductivity contributions. At 700 °C, SDC/STO films on (100) MgO exhibit a dominant ionic conductivity of about 7 × 10^?2 S cm^?1, down to pO₂ values of about 10^?15 atm. The absence of grain boundaries make the SDC/STO/MgO heterostructures stable to oxidation‐reduction cycles at high temperatures, in contrast to that observed for the more disordered SDC/STO films, which degraded after hydrogen exposure.     

V2V protocols for traffic congestion discovery along routes of interest in VANETs: a quantitative study

One of the most interesting and promising challenges for Intelligent Transportation Systems (ITSs) relates to the traffic congestion problem. Congestion is a relevant issue for transportation because it reduces the efficiency of infrastructure and increases travel time, air pollution, and fuel consumption. Nowadays, the most promising technology in support of ITSs is found in the domain of Vehicular Ad Hoc Networks (VANETs). In this paper, we propose three protocols that are able to transmit traffic information for routes of interest on VANETs without any Road Side Unit (RSU) support. The proposed protocols adopt strategies to improve the performance of packet routing based on the density and location of vehicles; moreover, they enable an interesting comparison of the performance achievable with either reactive or proactive approaches. The extensive performance results reported show how it is possible to limit the congestion monitoring overhead along Routes of Interest (ROIs), while maintaining a sufficiently high performance in terms of traffic reporting. This may be done by employing context‐aware data delivery techniques that autonomously adapt to runtime conditions. Copyright © 2016 John Wiley & Sons, Ltd.