Inclusion of Methoxybutropate in β-and Hydroxypropyl β-Cyclodextrins: Comparison of Preparation Methods

Interactions between methoxybutropate and β-cyclodextrin or hydroxypropyl β-cyclodextrin and the possibility of obtaining inclusion complexes have been evaluated by phase solubility diagram, HPLC, DSC, and x-ray diffractometry. Solid inclusion complexes were prepared by spray drying, kneading, and solid dispersion. The dissolution profiles of the obtained powders were studied in order to define the most appropriate cyclodextrin preparation method and molar ratio to use in the production of methoxybutropate inclusion complexes     

Tampering in RFID: A Survey on Risks and Defenses

RFID is a well-known pervasive technology, which provides promising opportunities for the implementation of new services and for the improvement of traditional ones. However, pervasive environments require strong efforts on all the aspects of information security. Notably, RFID passive tags are exposed to attacks, since strict limitations affect the security techniques for this technology. A critical threat for RFID-based information systems is represented by data tampering, which corresponds to the malicious alteration of data recorded in the tag memory. The aim of this paper is to describe the characteristics and the effects of data tampering in RFID-based information systems, and to survey the approaches proposed by the research community to protect against it. The most important recent studies on privacy and security for RFID-based systems are examined, and the protection given against tampering is evaluated. This paper provides readers with an exhaustive overview on risks and defenses against data tampering, highlighting RFID weak spots and open issues.     

MATTER: A tool for generating end-to-end IoT test scripts

Software Quality Journal - In the last few years, Internet of Things (IoT) systems have drastically increased their relevance in many fundamental sectors. For this reason, assuring their quality is...     

Development and characterization of an implantable biosensor for telemetric monitoring of ethanol in the brain of freely moving rats

Ethanol is one of the most widespread psychotropic agents in western society. While its psychoactive effects are mainly associated with GABAergic and glutamatergic systems, the positive reinforcing properties of ethanol are related to activation of mesolimbic dopaminergic pathways resulting in a release of dopamine in the nucleus accumbens. Given these neurobiological implications, the detection of ethanol in brain extracellular fluid (ECF) is of great importance. In this study, we describe the development and characterization of an implantable biosensor for the amperometric detection of brain ethanol in real time. Ten different designs were characterized in vitro in terms of Michaelis-Menten kinetics (V(MAX) and K(M)), sensitivity (linear region slope, limit of detection (LOD), and limit of quantification (LOQ)), and electroactive interference blocking. The same parameters were monitored in selected designs up to 28 days after fabrication in order to quantify their stability. Finally, the best performing biosensor design was selected for implantation in the nucleus accumbens and coupled with a previously developed telemetric device for the real-time monitoring of ethanol in freely moving, untethered rats. Ethanol was then administered systemically to animals, either alone or in combination with ranitidine (an alcohol dehydrogenase inhibitor) while the biosensor signal was continuously recorded. The implanted biosensor, integrated in the low-cost telemetry system, was demonstrated to be a reliable device for the short-time monitoring of exogenous ethanol in brain ECF and represents a new generation of analytical tools for studying ethanol toxicokinetics and the effect of drugs on brain ethanol levels.     

In Situ Attenuated Total Reflection (ATR/FT-IR) Tribometry: A Powerful Tool for Investigating Tribochemistry at the Lubricant–Substrate Interface

To investigate the chemical changes occurring at metal/lubricant interfaces under tribological conditions in the boundary-lubrication regime, an in situ system for conducting quantitative tribological measurements has been constructed by combining an attenuated total reflection Fourier-transform infrared (ATR/FT-IR) spectrometer with a reciprocating tribometer. By periodically acquiring ATR/FT-IR spectra during sliding, spectroscopic changes due to thermal and/or tribochemical reactions occurring at the metal/oil interface can be monitored and correlated with friction measurements. The usefulness of this tribological test system has been demonstrated by performing ATR tribological experiments in the presence of a poly-α-olefin base oil at high temperature (423 K) on iron-coated germanium ATR crystals.     

Non-lithographic SERS substrates: tailoring surface chemistry for Au nanoparticle cluster assembly

Near‐field plasmonic coupling and local field enhancement in metal nanoarchitectures, such as arrangements of nanoparticle clusters, have application in many technologies from medical diagnostics, solar cells, to sensors. Although nanoparticle‐based cluster assemblies have exhibited signal enhancements in surface‐enhanced Raman scattering (SERS) sensors, it is challenging to achieve high reproducibility in SERS response using low‐cost fabrication methods. Here an innovative method is developed for fabricating self‐organized clusters of metal nanoparticles on diblock copolymer thin films as SERS‐active structures. Monodisperse, colloidal gold nanoparticles are attached via a crosslinking reaction on self‐organized chemically functionalized poly(methyl methacrylate) domains on polystyrene‐block‐poly(methyl methacrylate) templates. Thereby nanoparticle clusters with sub‐10‐nanometer interparticle spacing are achieved. Varying the molar concentration of functional chemical groups and crosslinking agent during the assembly process is found to affect the agglomeration of Au nanoparticles into clusters. Samples with a high surface coverage of nanoparticle cluster assemblies yield relative enhancement factors on the order of 10⁹ while simultaneously producing uniform signal enhancements in point‐to‐point measurements across each sample. High enhancement factors are associated with the narrow gap between nanoparticles assembled in clusters in full‐wave electromagnetic simulations. Reusability for small‐molecule detection is also demonstrated. Thus it is shown that the combination of high signal enhancement and reproducibility is achievable using a completely non‐lithographic fabrication process, thereby producing SERS substrates having high performance at low cost.     

Engineering of poly(ε-caprolactone) microcarriers to modulate protein encapsulation capability and release kinetic

Drug delivery applications using biodegradable polymeric microspheres are becoming an important means of delivering therapeutic agents. The aim of this work was to modulate the microporosity of poly(ε-caprolactone) (PCL) microcarriers to control protein loading capability and release profile. PCL microparticles loaded with BSA (bovine serum albumin) have been de novo synthesized with double emulsion solvent evaporation technique transferred and adapted for different polymer concentrations (1.7 and 3% w/v) and stabilizer present in the inner aqueous phase (0.05, 0.5 and 1% w/v). SEM (scanning electron microscope) and CLSM (confocal laser scanning microscope) analysis map the drug distribution in homogeneously distributed cavities inside the microspheres with dimensions that can be modulated by varying double emulsion process parameters. The inner structure of BSA-loaded microspheres is greatly affected by the surfactant concentration in the internal aqueous phase, while a slight influence of polymer concentration in the oil phase was observed. The surfactant concentration mainly determines microspheres morphology, as well as drug release kinetics, as confirmed by our in-vitro BSA release study. Moreover, the entrapped protein remained unaltered during the protein encapsulation process, retaining its bio-activity and structure, as shown through a dedicated gel chromatographic analytical method.     

Mobile and Personal Communications in the 60 GHz Band: A Survey

This paper intends to present a summary of the technical issues arising in the exploitation of the 60 GHz mm-wave band for mobile and personal communications. The most significant applications proposed so far are surveyed, with particular emphasis placed on recent experimentation about millimeter-wave propagation for road/railway transportation as well as indoor scenarios. As a case study, the capacity of a (micro-)cellular Code Division Multiple Access (CDMA) network in the 60-GHz band is also evaluated in detail.     

Heart rate responses to social interactions in free-moving rhesus macaques (Macaca mulatta): A pilot study.

Heart rate telemetry was explored as a means to access animal emotion during social interactions under naturalistic conditions. Heart rates of 2 middle-ranking adult females living in a large group of rhesus macaques (Macaca mulatta) were recorded along with their behavior. Heart rate changes during 2 types of interactions were investigated, while controlling for the effects of posture and activity. The risk of aggression associated with the approach of a dominant individual was expected to provoke anxiety in the approachee. This prediction was supported by the heart rate increase after such an approach. No increase was found when the approacher was a kin or a subordinate individual. The tension-reduction function of allogrooming was also supported. Heart rate decelerated faster during the receipt of grooming than in matched control periods. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Preparation of nano-size ZrB2 powder by self-propagating high-temperature synthesis

Preparation of nano-size ZrB₂ powder by SHS has been investigated. Zr and B elemental powders were mixed with 10–50 wt.% NaCl, and prepared pellets were reacted under argon. Adiabatic temperatures were calculated by HSC software. Increasing NaCl content led to a continuous decrease in adiabatic temperatures and reaction wave velocity. Products were subjected to XRD, SEM and FESEM analyses. Average crystallite size of ZrB₂, which was 303 nm without NaCl, decreased to 32 nm with 40% NaCl addition. Distinct decrease in ZrB₂ particle size was also observed from SEM analyses. 30% NaCl addition was found to be optimum for ensuring a stable SHS reaction and providing the formation of nano-size ZrB₂ particles. It was revealed from particle size distribution measurements that ZrB₂ powder obtained by 30 wt.% NaCl addition contained particles mostly finer than 200 nm. A mechanism, similar to solution-precipitation was proposed for the particle size refining effect of NaCl.