Lipid composition and mitochondrial respiration in warm- and cold-adapted sea bass

The response to cold of liver and heart membrane lipid composition and mitochondrial respiration in reared sea bass (Dicentrarchus labrax L.) was investigated. Fish acclimation was followed during the natural seasonal cycle from August to March. The data on the fatty acid composition of liver and heart polar lipids and on total lipids of liver mitochondria and microsomes did not indicate any increase in unsaturation in response to cold. The enzyme complexes of the liver and heart mitochondrial respiratory chain showed a repeated negative compensation for cold acclimation. The constancy of the break in the Arrhenius plot of liver cytochrome oxidase (EC 1.9.3.1) was consistent with the lack of homeoviscous adaptation of membrane lipids. A thermoadaptive strategy based on the reduction of sea bass metabolic activity is suggested.     

A high-vacuum deposition system for in situ and real-time electrical characterization of organic thin-film transistors

We present a home-built high-vacuum system for performing organic semiconductor thin-film growth and its electrical characterization during deposition (real-time) or after deposition (in situ). Since the environment conditions remain unchanged during the deposition and electrical characterization process, a direct correlation between growth mode and electrical properties of thin film can be obtained. Deposition rate and substrate temperature can be systematically set in the range 0.1-10 ML∕min and RT-150 °C, respectively. The sample-holder configuration allows the simultaneous electrical monitoring of up to five organic thin-film transistors (OTFTs). The OTFTs parameters such as charge carrier mobility μ, threshold voltage V(TH), and the on-off ratio I(on)∕I(off) are studied as a function of the semiconductor thickness, with a submonolayer accuracy. Design, operation, and performance of the setup are detailed. As an example, the in situ and real-time electrical characterization of pentacene TFTs is reported.     

Virtual Screening against p50 NF‐κB Transcription Factor for the Identification of Inhibitors of the NF‐κB–DNA Interaction and Expression of NF‐κB Upregulated Genes

Virtual screening against NF‐κB p50 using docking simulations was applied by starting from a three‐dimensional (3D) database containing more than 4.6 million commercially available structures. This database was filtered by specifying a subset of commercially available compounds sharing a (2E,Z)‐3‐(2‐hydroxyphenyl)‐2‐propenoate substructure and relevant druglike properties. Docking to p50 NF‐κB was performed with a test set of six known inhibitors of NF‐κB–DNA interactions. In agreement with docking results, the highest‐scored compound displayed a high level of inhibitory activity in electrophoretic mobility shift assay (EMSA) experiments (inhibition of NF‐κB–DNA interactions) and on biological functions dependent on NF‐κB activity (inhibition of IL‐8 gene expression in cystic fibrosis IB3‐1 cells). We found that this in silico screening approach is suitable for the identification of low‐molecular‐weight compounds that inhibit NF‐κB–DNA interactions and NF‐κB‐dependent functions. Information deduced from the discovery of the new lead compound and its binding mode could result in further lead optimization resulting in more potent NF‐κB inhibitors.     

Magnetic proximity effect as a pathway to spintronic applications of topological insulators

Spin-based electronics in topological insulators (TIs) is favored by the long spin coherence(1,2) and consequently fault-tolerant information storage. Magnetically doped TIs are ferromagnetic up to 13 K,(3) well below any practical operating condition. Here we demonstrate that the long-range ferromagnetism at ambient temperature can be induced in Bi(2-x)Mn(x)Te(3) by the magnetic proximity effect through deposited Fe overlayer. This result opens a new path to interface-controlled ferromagnetism in TI-based spintronic devices.     

Role and Optimization of the Active Oxide Layer in TiO2‐Based RRAM

TiO₂ is commonly used as the active switching layer in resistive random access memory. The electrical characteristics of these devices are directly related to the fundamental conditions inside the TiO₂ layer and at the interfaces between it and the surrounding electrodes. However, it is complex to disentangle the effects of film “bulk” properties and interface phenomena. The present work uses hard X‐ray photoemission spectroscopy (HAXPES) at different excitation energies to distinguish between these regimes. Changes are found to affect the entire thin film, but the most dramatic effects are confined to an interface. These changes are connected to oxygen ions moving and redistributing within the film. Based on the HAXPES results, post‐deposition annealing of the TiO₂ thin film was investigated as an optimisation pathway in order to reach an ideal compromise between device resistivity and lifetime. The structural and chemical changes upon annealing are investigated using X‐ray absorption spectroscopy and are further supported by a range of bulk and surface sensitive characterisation methods. In summary, it is shown that the management of oxygen content and interface quality is intrinsically important to device behavior and that careful annealing procedures are a powerful device optimisation technique.     

A 64-min single-chip voice recorder/player using embedded 4-b/cellflash memory

A system-on-chip prototype implementing a full integration of a 64-minute digital voice recorder/player and embedding a 4-b/cell multilevel digital flash memory is presented in this paper. A hardwired adaptive-differential pulse-code modulation speech coder/decoder (8 to 40 kb/s) and a microcontroller are integrated into a bus-centric architecture. An 8-Mcell/32-Mb multilevel flash memory is used as an embedded mass storage media and a fully digital on-chip built-in-self-test solution is presented. This speech recording system features a modular architecture allowing full reuse and mix-and-match of its IP building blocks. The architecture of the system and solutions for implementing embedded multilevel flash memories are presented. System operation modes are described showing how the desired message editing functionality is implemented by a mixed hardware/software solution. The chip is 3-V-only and it counts 13 M transistors at 225 mm² area in a 0.5-μm embedded flash technology     

A low-power integrated circuit for remote speech recognition

In this paper, a low-power, low-voltage speech processing system is presented. The system is intended to he used in remote speech recognition applications where feature extraction is performed on terminal and high-complexity recognition tasks and moved to a remote server accessed through a radio link. The proposed system is based on a CMOS feature extraction chip for speech recognition that computes 15 cepstrum parameters, each 8 ms, and dissipates 30 μW at 0.9-V supply. Single-cell battery operation is achieved. Processing relies on a novel feature extraction algorithm using 1-bit A/D conversion of the input speech signal. The chip has been implemented as a gate array in a standard 0.5-μm, three-metal CMOS technology. The average energy required to process a single word of the TI46 speech corpus is 10 μJ. It achieves recognition rates over 98% in isolated-word speech recognition tasks     

Droplet Digital PCR for Non-Invasive Prenatal Detection of Fetal Single-Gene Point Mutations in Maternal Plasma

Non-invasive prenatal testing (NIPT) is based on the detection and characterization of circulating cell-free fetal DNA (ccffDNA) in maternal plasma and aims to identify genetic abnormalities. At present, commercial NIPT kits can detect only aneuploidies, small deletions and insertions and some paternally inherited single-gene point mutations causing genetic diseases, but not maternally inherited ones. In this work, we have developed two NIPT assays, based on the innovative and sensitive droplet digital PCR (ddPCR) technology, to identify the two most common β thalassemia mutations in the Mediterranean area (β⁺IVSI-110 and β⁰39), maternally and/or paternally inherited, by fetal genotyping. The assays were optimized in terms of amplification efficiency and hybridization specificity, using mixtures of two genomic DNAs with different genotypes and percentages to simulate fetal and maternal circulating cell-free DNA (ccfDNA) at various gestational weeks. The two ddPCR assays were then applied to determine the fetal genotype from 52 maternal plasma samples at different gestational ages. The diagnostic outcomes were confirmed for all the samples by DNA sequencing. In the case of mutations inherited from the mother or from both parents, a precise dosage of normal and mutated alleles was required to determine the fetal genotype. In particular, we identified two diagnostic ranges for allelic ratio values statistically distinct and not overlapping, allowing correct fetal genotype determinations for almost all the analyzed samples. In conclusion, we have developed a simple and sensitive diagnostic tool, based on ddPCR, for the NIPT of β⁺IVSI-110 and β⁰39 mutations paternally and, for the first time, maternally inherited, a tool, which may be applied to other single point mutations causing monogenic diseases.     

Hydrophilic self-assembly monolayers for pentacene-based thin-film transistors

A series of hydrophilic alkanethiols, HS(CH₂)_nOH with n = 3, 4, 6, 8, 9 and 11, have been self-assembled on gold electrodes of pentacene-based thin-film transistors. The multi-parametric and ultra-sensitive response of these devices allows us to characterize both charge–injection and electrical stability moving from vacuum to air. The decay exponent β of charge injection is found to be 0.7–1.1 Å^?1 in agreement with earlier measurements of charge tunneling done by electrochemistry and large-area molecular junctions. We find that the intermediate chain lengths (n = 4 and 6) yield an optimum response as they represent the best compromise in terms of decrease of the contact-resistance and bias stress.