Magnetic resonance evaluation of autonomous thyroid nodules treated by percutaneous ethanol injection

Magnetic resonance (MR) imaging was used to evaluate the effect of ultrasound-guided percutaneous ethanol injection (PEI) of autonomous thyroid nodules (ATNs). Nine patients affected with ATN (3.7–32.2 mL volume) underwent PEI (4–19 mL ethanol, subdivided in 3–6 weekly procedures). MR imaging (1.5 T) was performed before each alcoholization and 1 month after the last PEI procedure with the following parameters:T ₁-(550/12) andT ₂-weighted (2200/160) spin-echo images; 4-mm slices, 10% gap; coronal planes. A further seven patients with normal thyroid function, who had undergone PEI 6–18 months before, underwent an MR examination with the same parameters. The signal-to-noise ratio (S/N) of ATN and extranodular gland, as well as ATN volume, were evaluated on theT ₂-weighted images. OnT ₁-weighted images, ATNs appeared mostly hypointense before treatment, with hyperintense areas during treatment, and were lightly hyperintense 6–18 months after treatment. S/N onT ₂-weighted images: extranodular gland 3.5–9.2; ATNs, before treatment 13.2–19.7, before the last procedure 7.7–11.6, 1 month after the last procedure 5.6–10.9; previously treated ATNs, 4.3–8.2. No significant volume reduction was observed with MR 1 month after the last procedure. The MR examination time was about 15 minutes. In conclusion, the effect of PEI on ATNs can be evaluated with an MR examination that is not very time consuming.     

An efficient implementation of PRNGs based on the digital sawtooth map

In this paper, the sawtooth map digitally implemented is analysed to evaluate its suitability for pseudo‐random binary numbers generation. Period and statistical properties of the sequences generated by the digital map are evaluated versus arithmetic precision, approximation strategy and characteristic parameter of the map. In general, the digital implementation of the sawtooth map requires the use of a multiplier, which is quite expensive in terms of gate count. However, results show that values of design parameters that lead to adequate statistical features and to a relatively high period also allow for significantly reducing the complexity required in the implementation. To better evaluate performance of the digital sawtooth map as a pseudo‐random number generator, it is compared to a linear feedback shift register with the same number of flip‐flops, which is well known for its output sequences with a long period, appealing statistical quality, and for a reduced gate count. Performance comparison and implementation on a programmable logic device show that the digital sawtooth map is suitable for pseudo‐random number generation, also requiring a relatively small amount of hardware. Copyright © 2004 John Wiley & Sons, Ltd.     

Determining bound states in a semiconductor device with contacts using a nonlinear eigenvalue solver

We present a nonlinear eigenvalue solver enabling the calculation of bound solutions of the Schrödinger equation in a system with contacts. We discuss how the imposition of contacts leads to a nonlinear eigenvalue problem and discuss the numerics for a one- and two-dimensional potential. We reformulate the problem so that the eigenvalue problem can be efficiently solved by the recently proposal rational Krylov method for nonlinear eigenvalue problems, known as NLEIGS. In order to improve the convergence of the method, we propose a holomorphic extension such that we can easily deal with the branch points introduced by a square root. We use our method to determine the bound states of the one-dimensional Pöschl–Teller potential, a two-dimensional potential describing a particle in a canyon and the multi-band Hamiltonian of a topological insulator.     

Stigmergic electronic gates and networks

Stigmergy is a communication method based on changing the surrounding environment according to reference feedbacks. It is typical within animal colonies that are able to process even complex information by releasing signals into the environment, which are subsequently received and processed by other elements of the colony. For example, ants searching for food leave traces of a pheromone, like Hansel and Gretel’s breadcrumbs, along the way. When food is found, they return to the anthill reinforcing this pheromone trace as a signal and reminder to all the others. Similar techniques are used in routing software even if stigmergic hardware might be even more efficient, fast, and energy saving. Recently, a stigmergic photonic gate based on soliton waveguides has been proposed; this particular stigmergic hardware can switch the output ratio of the channels as a result of optical feedback. Based on these results, in this study, we analyze stigmergic electronic gates that can be addressed through external feedback, as the photonic ones do. We show that the nonlinear response of such gates must be based on quadratic saturating conductances driven by feedback signals. For this purpose, networks of stigmergic gates require two parallel and communicating current circuits: one to transmit information, and another for feedback signals to control the gate switching. We also show that by increasing the number of terminals per single gate, from 2 × 2 to 3 × 3 or higher, the overall power consumption can be reduced by a few orders of magnitude.

     

Endothelial Progenitor Cells: An Appraisal of Relevant Data from Bench to Bedside

The mobilization of endothelial progenitor cells (EPCs) into circulation from bone marrow is well known to be present in several clinical settings, including acute coronary syndrome, heart failure, diabetes and peripheral vascular disease. The aim of this review was to explore the current literature focusing on the great opportunity that EPCs can have in terms of regenerative medicine.     

DC and pulsed measurements of on-state breakdown voltage in GaAs MESFETs and InP-based HEMTs

The BV_DS–I_D breakdown characteristics of MESFET and HEMT devices measured at constant gate current are correlated with conventional measurements of gate current due to impact-ionization. The influence of thermal effects on breakdown DC measurements is demonstrated. By adopting pulsed measurements, we confirm that on-state breakdown voltage of InP HEMTs decreases by increasing the temperature, while the opposite occurs in GaAs based MESFETs and HEMTs. We show that DC measurements are not suitable for evaluating on-state breakdown of power MESFETs and HEMTs, and we propose pulsed measurements as a viable alternative.     

Cationic Block Copolymer Nanoparticles with Tunable DNA Affinity for Treating Rheumatoid Arthritis

A high concentration of cell‐free DNA (cfDNA) in joints is considered a disease causative agent of rheumatoid arthritis (RA) and cfDNA scavenging has been regarded as an efficient therapeutic avenue. Cationic polymers can hamper progression of joint inflammation in a rat model of RA by scavenging cfDNA; however, they may cause systemic toxicity due to the strong positive charges. To reduce the toxicity, herein a library of cationic nanoparticles (cNPs) of block copolymer micelles is developed and the effects of structure and surface composition on cNP efficacy to bind nucleic acids, toxicity, and therapeutic activity on a collagen induced arthritis (CIA) rat model of RA are assessed. The library includes cNPs with a homoshell from poly(lactic‐co‐glycolic acid)‐block‐poly(2‐(dimethylamino)ethyl methacrylate) (PLGA‐b‐PDMA) block copolymers and cNPs with a mixed shell of poly(ethylene glycol) (PEG) and PDMA by coself‐assembling PLGA‐b‐PDMA and PLGA‐b‐PEG block copolymers. Relatively to the homoshell cNPs, introduction of PEG segments translates into a lower DNA binding efficacy while preserving ability to hamper joint inflammation. Moreover, they show a greater accumulation and longer retention at the inflamed joints, allowing a lower administration frequency. In conclusion, this work shows that the therapeutic index of cationic materials can be tuned by introducing surface neutral moieties.     

A 100 dB Dynamic-Range CMOS Vision Sensor With Programmable Image Processing and Global Feature Extraction

A 128 times 64 pixel programmable vision sensor performs real-time analog image processing over high dynamic range images is reported. The pixel-parallel single instruction multiple data (SIMD) architecture executes real-time spatio-temporal filtering with 2.8 GOPS/mm² and large flexibility in coefficient assignment. The sensor uses time-based and pulse-based operating modalities to execute spatio-temporal filtering on images with dynamic range up to about 100 dB. The in-pixel processing is based on two operations: the absolute value of voltage difference and accumulation of partial results. Feature extraction from the entire image is also possible without the need for image dispatching, thus optimizing both processing speed and video bandwidth. The 32.6 mum square pixel, with a fill-factor of 24%, consists of two analog memories and 28 transistors. The sensor, fabricated in 0.35 mum CMOS technology, gives a fixed pattern noise (FPN) of 0.8% and power consumption of 14 mW at 3.3 V     

Automatic authoring and construction of hypermedia for information retrieval

This paper describes the complete process and a tool for the automatic construction of a multimedia hypertext starting from a large collection of multimedia documents. Through the use of an authoring methodology, the document collection is automatically authored, and the result is a multimedia hypertext, also called a hypermedia, written in hypertext mark-up language (HTML), almost a standard among hypermedia mark-up languages. The resulting hypermedia can be browsed and queried with Mosaic, an interface developed in the framework of the World Wide Web Project. In particular, the set of methods and techniques used for the automatic construction of hypermedia is described in this paper, and their relevance in the context of multimedia information retrieval is highlighted.