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Molecularly imprinted polymers (MIP) are materials capable of recognizing specific molecules, usually through non-covalent bonds. In this work, gallic acid (GA) was selected as the imprinting molecule, and MIP for GA (MIP-GA) was synthesized by bulk polymerization. X-ray photoelectron spectroscopy (XPS) and near-edge X-ray absorption fine structure (NEXAFS) confirmed the MIP-GA recognition property. Poly(caprolactone) mat containing MIP-GA particles (MIM-GA) was produced by electrospinning, which was morphologically characterized by Scanning electron microscopy (SEM). Functionalized MIM-GA was obtained by washes sequence in methanol for the GA removal from MIM-GA. The GA removal was confirmed by High-performance liquid chromatography (HPLC) with UV-Vis detection at 214 and 268 nm. The functionalized MIM-GA immersed in GA methanolic solution with a concentration of 1.0 mM extracted 96±1.5% of GA at t = 150 minutes. The vibrational modes obtained from FT-IR spectra confirmed the chemical composition of MIM-GA and its functionalization through of band at 770 cm-1. The contact angle measurements were 134.0±1.0° for electrospun MIM-GA and 125.0±1.2° for functionalized MIM-GA. The decrease was due to the absence of GA after the functionalization process. The produced MIM-GA by electrospinning acquired the recognition property of the GA imprinted polymer synthesized, which can be used for the specific detection, extraction, and purification of this important natural polyphenol. [ABSTRACT FROM AUTHOR]

Multilayer (14 layers, 115–122 nm thick each) BiFeO3/CoFe2O4/substrate (BFO/CFO) and CoFe2O4/BiFeO3/substrate (CFO/BFO) nanocomposites were obtained by the method of sol-gel synthesis. It is shown that all samples of the obtained nanocomposites have multiferroic properties at room temperature. At the same time, there is a clearly demonstrated effect of the layering order on the values of remnant polarization and magnetization of these samples. This influence originates from the much smaller size of the crystallites in the BiFeO3 layers for the samples deposited in order (BFO/CFO) at various annealing temperatures (700, 725, and 750 °C). [ABSTRACT FROM AUTHOR]

Ultrasound (US) allows real-time tumor assessment. We evaluated the volumetric limits of 2-D and 3-D US, compared with magnetic resonance imaging (MRI), with a prospective institutional review board-approved clinical evaluation of US-to-MRI volumetric correlation. US images of pre- and post-neoadjuvant breast cancers were obtained. Volume discrepancy was evaluated with the non-parametric Wilcoxon signed-rank test. Expected inter-observer variability <14% was evaluated as relative paired difference (RPD); clinical relevance was gauged with the volumetric standard error of the mean (SEM). For 42 patients, 133 of 170 US examinations were evaluable. For tumors ≤20 cm3, both highly correlated to MRI with RPD within inter-observer variability and Pearson's correlation up to 0.86 (0.80 before and 0.86 after neoadjuvant chemotherapy, respectively). Lesions 20-40 cm3 had US-to-MRI discrepancy within inter-observer variability for 2-D (RPD: 13%), but not 3-D (RPD: 27%) US (SEM: 1.47 cm3 for 2-D, SEM: 2.28 cm3 for 3-D), suggesting clinical utility. Tumors >40 cm3 correlated poorly. Tumor volumes ≤20 cm3 exhibited a good correlation to MRI. Studies of clinical applications are warranted. [ABSTRACT FROM AUTHOR]

ATP released from neurons and astrocytes during neuronal activity or under pathophysiological circumstances is able to influence information flow in neuronal circuits by activation of ionotropic P2X andmetabotropic P2Y receptors and subsequentmodulation of cellular excitability, synaptic strength, and plasticity. In the present paper we review cellular and network effects of P2Y receptors in the brain.We show that P2Y receptors inhibit the release of neurotransmitters,modulate voltage- and ligand-gated ion channels, and differentially influence the induction of synaptic plasticity in the prefrontal cortex, hippocampus, and cerebellum. The findings discussed heremay explain howP2Y1 receptor activation during brain injury, hypoxia, inflammation, schizophrenia, orAlzheimer’s disease leads to an impairment of cognitive processes. Hence, it is suggested that the blockade of P2Y1 receptors may have therapeutic potential against cognitive disturbances in these states. [ABSTRACT FROM AUTHOR]

Highlights: [•] We model the transmission line with frequency dependent parameters in the harmonic domain. [•] Reformulate the relationship for voltages and currents between the receiving end and any point on the transmission line. [•] Propose a representation of the TCSC given by a complex admittance matrix, which includes the cross-couplings between harmonic frequencies. [•] Presents a harmonic propagation analysis, including the effects of all the harmonic content and the cross coupling between harmonics. [•] Presents the harmonic interaction between the linear and nonlinear parts in the system. [ABSTRACT FROM AUTHOR]

This paper presents the design and experimental results of a clock generator for high-frequency, continuous-time,converters. The circuit was fabricated in a-V,-nm CMOS technology along with twomodulators intended for the digitisation of UWB signals. The clock generator is based on a PLL frequency synthesiser with a low phase noise LC Voltage-controlled oscillatror (VCO). This kind of oscillator achieves the required low jitter specification with a substantial lower power consumption than a conventional ring VCO. In order to save die area, the VCO was made to operate at four times the desired clock frequency ofMHz, and a compact multi-layer inductor was used. A system clock with a cycle-to-cycle jitter of onlyof its period is obtained. The total circuit area isand the resulting power consumption is. [ABSTRACT FROM AUTHOR]

This paper presents a review with a concise description and analysis of the fundamentals, characteristics, analytical details, merits, and drawbacks associated with existing methods in frequency and time domain for harmonic analysis in practical power networks. The description and analysis are centered on methods developed in the harmonic domain, hybrid frequency-time domain, and time domain, respectively. Validation of the reviewed methods for harmonic analysis, against one of the widely accepted digital simulators, such as EMTP, EMTDC, or MATLAB/SIMULINK, is reported in the cited individual contributions. [ABSTRACT FROM PUBLISHER]

CA3 pyramidal neurons are important for memory formation and pattern completion in the hippocampal network. It is generally thought that proximal synapses from the mossy fibers activate these neurons most efficiently, whereas distal inputs from the perforant path have a weaker modulatory influence. We used confocally targeted patch-clamp recording from dendrites and axons to map the activation of rat CA3 pyramidal neurons at the subcellular level. Our results reveal two distinct dendritic domains. In the proximal domain, action potentials initiated in the axon backpropagate actively with large amplitude and fast time course. In the distal domain, Na+ channel-mediated dendritic spikes are efficiently initiated by waveforms mimicking synaptic events. CA3 pyramidal neuron dendrites showed a high Na+-to-K+ conductance density ratio, providing ideal conditions for active backpropagation and dendritic spike initiation. Dendritic spikes may enhance the computational power of CA3 pyramidal neurons in the hippocampal network. [ABSTRACT FROM AUTHOR]

Abstract: Long-term depression (LTD) is a form of synaptic plasticity that may contribute to information storage in the central nervous system. Here we report that LTD can be elicited in layer 5 pyramidal neurons of the rat prefrontal cortex by pairing low frequency stimulation with a modest postsynaptic depolarization. The induction of LTD required the activation of both metabotropic glutamate receptors of the mGlu1 subtype and voltage-sensitive Ca2+ channels (VSCCs) of the T/R, P/Q and N types, leading to the stimulation of intracellular inositol trisphosphate (IP3) receptors by IP3 and Ca2+. The subsequent release of Ca2+ from intracellular stores activated the protein phosphatase cascade involving calcineurin and protein phosphatase 1. The activation of purinergic P2Y1 receptors blocked LTD. This effect was prevented by P2Y1 receptor antagonists and was absent in mice lacking P2Y1 but not P2Y2 receptors. We also found that activation of P2Y1 receptors inhibits Ca2+ transients via VSCCs in the apical dendrites and spines of pyramidal neurons. In addition, we show that the release of ATP under hypoxia is able to inhibit LTD by acting on postsynaptic P2Y1 receptors. In conclusion, these data suggest that the reduction of Ca2+ influx via VSCCs caused by the activation of P2Y1 receptors by ATP is the possible mechanism for the inhibition of LTD in prefrontal cortex. [ABSTRACT FROM AUTHOR]

A recent paper by von Engelhardt et al. identifies a novel auxiliary subunit of native AMPARs, termed CKAMP44. Unlike other auxiliary subunits, CKAMP44 accelerates desensitization and prolongs recovery from desensitization. CKAMP44 is highly expressed in hippocampal dentate gyrus granule cells and decreases the paired-pulse ratio at perforant path input synapses. Thus, both principal and auxiliary AMPAR subunits control the time course of signaling at glutamatergic synapses. [Copyright &y& Elsevier]

In this contribution a solution to the parallel resonance problem that can be present in practical applications of shunt Active Power Filter (APF) compensation is proposed. The proposed solution involves turning the shunt APF scheme of compensation into a Shunt Hybrid Filter (SHF) configuration. A Linear Quadratic Regulator (LQR)-based switching controller was specifically designed for this hybrid scheme of compensation, maintaining stringent performance requirements on the tracking of filtering currents and the draining of the harmonic ripple currents. Results obtained with Matlab/Simulink® illustrate an effective and sound system of compensation which also reduces the necessary KVA rating of the APF. [ABSTRACT FROM AUTHOR]

A comprehensive analysis of the impact of the finite gain-bandwidth product (GBW) in amplifiers and the excess loop delay on a parallel inultibit CT AE ADC for an orthogonal frequency division multiplexing OFDM ultra-wideband (UWB) receiver has been carried out in this paper. The overall converter consists of two CT AS modulators covering two sub-bands (each of them implemented by a third and a fourth order CT AE modulator) that are arranged to operate in parallel. Our study was based on the dependence of the noise transfer function (NTF) poles and zeroes locus in the z-plane on these two nonideal effects for both modulators from a theoretical approach. The corresponding STFs were also analytically evaluated. System-level simulations have been accomplished too. Amplifiers were modeled according to a single-pole transfer function. Using the modified Z-transform method the dependence of the NTF poles and zeroes locus in the z-plane on the finite GBW and on excess loop delay was obtained when the DAC pulse end occurs in the current ("early") or in the following ("late") clock cycle. NTF poles and zeroes loci were evaluated as a function of the two nonideal effects considered sepa-rately or combined. [ABSTRACT FROM AUTHOR]

Abstract: A detailed analysis of the impact of a hysteretic quantizer on a multibit, Sigma-Delta modulator has been carried out in this paper. Both discrete-time and continuous-time modulators have been considered. A qualitative modeling of the hysteretic quantizer based on a hysteretic block followed by an ideal quantizer was proposed. Due to the hysteresis effect, the quantizer output signal is delayed and distorted with respect to the quantizer input signal, where the delay causes a phase-shift independent on the signal frequency. Yet, the effect of the hysteresis depends on the input signal amplitude. This model was validated by using system-level simulations for a second order, 3-bit, discrete-time Sigma-Delta modulator. A linear model for hysteresis was derived by assuming a narrow hysteresis cycle. The quantizer input signal plays a fundamental role in the discussion. In order to include this signal into the linear analysis some approximations are proposed. The quantizer output signal is decomposed by the use of the Fourier series analysis only into the in-phase and quadrature components (with respect to the input signal) whose Fourier series coefficients can be analytically calculated. A quantitative analysis for both a second order, 3-bit, DT and CT Sigma-Delta modulators including a hysteretic quantizer was carried out. For the CT modulator, finite GBW in amplifiers, excess loop delay, and a hysteretic quantizer were considered separately and combined. A good agreement with both system-level simulations and experimental results is found, despite the approximations considered for the quantizer input signal. [ABSTRACT FROM AUTHOR]

Abstract: A comprehensive study of the impact of the finite gain-bandwidth product (GBW) in amplifiers and the excess loop delay on CT modulators has been carried out in this paper. Variations in the modulator coefficients have been included too. Considering a second order modulator, our study was based on the dependence of the NTF poles and zeroes locus in the z-plane on these two non-ideal effects from both an analytical and a computer simulation approach. The corresponding STFs were also analytically evaluated. The theoretical and the simulated results have been compared with the experimental results obtained from a test-chip recently designed and implemented. Amplifiers were modeled according to a single-pole transfer function. Using the modified Z-transform method the dependence of the NTF poles and zeroes locus in the z-plane on the finite GBW and on excess loop delay was obtained when the DAC pulse end occurs in the current (“early”) or in the following (“late”) clock cycle. Once the theoretical analysis was validated, NTF poles and zeroes loci were evaluated as a function of the two non-ideal effects considered separately or combined. In each case, the order of the modulator loop filter was discussed. The finite GBW effect can be compensated including an intentional “early” DAC pulse. This pulse can be implemented in the modulator by changing the sampling instant in the embedded ADC with respect to the instant DACs are enabled by using a simple delay circuit for the ADC clock. Thus, the modulator power consumption can be significantly reduced. [Copyright &y& Elsevier]

Power quality (PQ) in microgrids is a relevant topic, particularly with the complex dynamic behaviour of disturbances produced by the electronic components intrinsic in these technologies. In this paper, a qualitative-quantitative hybrid approach named multiscale recurrence quantification decomposition (MSRQD) combined with support vector machines (SVM) is proposed for PQ monitoring in microgrid systems. MSRQD combines variational mode decomposition (VMD) with recurrence quantification analysis (RQA). To validate the effectiveness of the proposed method, it is compared against other methods. In addition, three study cases are conducted in a microgrid test system using simulations, and real measured data of a main distribution feeder to prove the classification capability of the proposed method in a real environment. This novel approach, provides qualitative graphics and quantitative statistical indexes for disturbance localisation, disturbance time evolution and disturbance characterisation, as well as 3D visualisation feature space of perturbations that makes easy the interpretation to the system operator. [ABSTRACT FROM AUTHOR]

In this article a current-mode, second-order, CT Sigma-Delta modulator operating at a sampling frequency of 25 MHz and with an oversampling ratio of 64 has been designed. The modulator consists of current-mode, differential integrators based on a single-stage folded cascode topology and switched capacitors DACs cells generating exponential feedback waveforms. The modulator was analysed in detail from both a system- and a circuit-level point of view. A 'short' exponential DAC pulse, namely, an exponential pulse whose time constant is lower than the pulse width, was used to improve jitter rejection. Modulator feedback coefficients were analytically derived for an exponential feedback waveform. Jitter considerations paying special attention to its impact on CT Sigma-Delta modulators were presented, and two different contributions distinguished: independent jitter and accumulated jitter. Finally, functional- and transistor-level simulations have been accomplished to obtain significant features of the modulator performance. [ABSTRACT FROM AUTHOR]

Abstract: In this work the design of a continuous-time modulator for Gigabit Ethernet applications is presented. The input bandwidth and oversampling ratio are, respectively, 62.5MHz and 8, resulting in a clock frequency of 1GHz. It was designed and implemented in a standard 90nm CMOS technology. The active area of the modulator measures . It consists of a loop filter based on RC-opamp integrators and a 3-bit quantizer which includes a data weighted averaging scrambler. A digital tuning scheme to deal with process variations has also been included. System level simulations including several non-ideal effects have been carried out in order to determine in detail the performance of the converter. Experimental results show a resolution of 7.1 effective bits, and a power consumption of 10.8mW from a nominal power supply of 1V. [Copyright &y& Elsevier]

A very low voltage solution for the realization of the hold capacitor in a Track&Hold circuit based on an open-loop architecture is introduced. The circuit is a modification based on the switched opamp approach of the Track&Hold circuit using Miller Capacitance. Simulations show that the circuit is able to operate at 1V 1MS/s with a Total Harmonic Distortion of -64 dB @ 100 kHz and a very low power consumption of 80 µW. [ABSTRACT FROM AUTHOR]

Introduction: Nocturnal tongue biting as an isolated entity has been rarely reported. In the few published cases has not been possible to observe the tongue biting itself. The aim of this communication is the presentation of a patient in whom this symptom was dramatically presented due to its intensity and frequency and in which after several studies we were able to confirm eventually the tongue biting using video-EEG recording in a day nap. Materials and methods: A 18year old boy had been presenting, since 12year old, several episodes per week of nocturnal tongue biting during sleep. He has a past history of a severe traffic crash with craneoencephalic trauma, but without evident lesions in the MRI. Seriated EEGs were performed in basal conditions or after sleep deprivation and a photo paroxistic response with generalized discharges was evidenced at intermediate photostimulation frecuencies (10–15Hertzs). Anticonvulsant therapy was initiated that controlled the episodes, reappearing after the withdrawal. At that moment, a video-EEG recording was performed. Results: During the video-EEG study the patient presented one episode of tongue biting during sleep, without the presence of epileptiform abnormalities in the EEG. In this basis, the episodes were diagnosed as facio-mandibular myoclonus. Conclusion: During sleep, several motor activities affecting oro-facial musculature have been described, both physiological and pathological entities. Apart from the facio-mandibular myoclonus, the differential diagnosis comprises the orofacial automatisms, the bruxism, the epilepsy or the parasomnias with rhythmic or periodic movements. In our case, the final diagnosis was delayed and several treatments were essayed, and this allowed us to analyze the response to them. [Copyright &y& Elsevier]