Ms Range Research Articles

Threatening an Illusory Limb: An Event-related Potential Study of the Rubber Hand Illusion.

The rubber hand illusion (RHI) is a well-established method for studying body ownership: Given adequate concordance of visual, sensory, and proprioceptive stimuli, the individual experiences a rubber hand as his or her own. To study the effects of a threat to the rubber hand. We created a typical RHI paradigm but added threatening pain: Both the real hand of an individual and the rubber hand were stroked with a brush, either synchronously (RHI-inducing condition) or asynchronously (control condition), but only the rubber hand was then pricked with a needle to create a threatening pain condition. Event-related potentials (ERPs) were recorded in a group of 23 typically-developed individuals. ERP effects were source-localized using low-resolution electromagnetic tomography. The individuals consistently reported experience of the RHI during the experiment when the brush strokes were applied synchronously to both the real hand and the rubber hand. ERP analysis revealed that synchronous brush stroking gave rise to higher amplitude of frontal ERPs in the 100-200 ms range than asynchronous brush stroking, which was interpreted as reflecting the RHI. In the threatening pain condition, ERPs showed a greater positivity at frontocentral electrodes, source localized in the supplementary motor area (SMA). SMA activation could reflect a control mechanism over reflexive motor activity, facilitating a possible threat-related response. Further studies should address ERP effects and the extent of the RHI to standard and threat stimuli in a correlative fashion to further elucidate the functional significance of the neurophysiological findings.

A Cascaded Multi-Agent Reinforcement Learning-Based Resource Allocation for Cellular-V2X Vehicular Platooning Networks.

The platooning of cars and trucks is a pertinent approach for autonomous driving due to the effective utilization of roadways. The decreased gas consumption levels are an added merit owing to sustainability. Conventional platooning depended on Dedicated Short-Range Communication (DSRC)-based vehicle-to-vehicle communications. The computations were executed by the platoon members with their constrained capabilities. The advent of 5G has favored Intelligent Transportation Systems (ITS) to adopt Multi-access Edge Computing (MEC) in platooning paradigms by offloading the computational tasks to the edge server. In this research, vital parameters in vehicular platooning systems, viz. latency-sensitive radio resource management schemes, and Age of Information (AoI) are investigated. In addition, the delivery rates of Cooperative Awareness Messages (CAM) that ensure expeditious reception of safety-critical messages at the roadside units (RSU) are also examined. However, for latency-sensitive applications like vehicular networks, it is essential to address multiple and correlated objectives. To solve such objectives effectively and simultaneously, the Multi-Agent Deep Deterministic Policy Gradient (MADDPG) framework necessitates a better and more sophisticated model to enhance its ability. In this paper, a novel Cascaded MADDPG framework, CMADDPG, is proposed to train cascaded target critics, which aims at achieving expected rewards through the collaborative conduct of agents. The estimation bias phenomenon, which hinders a system's overall performance, is vividly circumvented in this cascaded algorithm. Eventually, experimental analysis also demonstrates the potential of the proposed algorithm by evaluating the convergence factor, which stabilizes quickly with minimum distortions, and reliable CAM message dissemination with 99% probability. The average AoI quantity is maintained within the 5-10 ms range, guaranteeing better QoS. This technique has proven its robustness in decentralized resource allocation against channel uncertainties caused by higher mobility in the environment. Most importantly, the performance of the proposed algorithm remains unaffected by increasing platoon size and leading channel uncertainties.

(Invited) Molecular Donor-Acceptor Systems Derived from Aromatic Heterocycle-Fused Porphyrins

Photoinduced charge separation (CS) in molecular donor-acceptor (D-A) systems is crucial for achieving efficient solar energy conversion in various applications. Despite significant efforts to develop molecular D-A systems over the past decades, it remains a challenge to bring the lifetime of the charge separation state to ms range, which is much shorter than the CS lifetime (~1 s) in natural photosynthetic systems. In this talk, a donor-acceptor system with long-lived charge-separation state (37.2 μs) will be presented. This donor-acceptor system was derived from π-extended porphyrins fused with aromatic heterocycles. Porphyrins fused with aromatic heterocycles represent one fascinating yet very challenging frontiers in chemistry and materials science.1-4 The Wang group has been engaged in developing concise and versatile synthetic and functionalization methods for π-extended porphyrins. The availability of these methods offers easy access to many π-extended porphyrins with novel functionalities.5-7 In this talk, the synthesis, characterization, and the optical and photophysical properties of π-extended porphyrins fused with 5-, 6, and 7-membered rings including 12H-benzo[f]benzo[4,5]imidazo[2,1-a]isoindole and 1,10-phenanthroline, porphyrins will also be presented. Reference Stepien, E. Gonka, M. Zyla and N. Sprutta, Chem. Rev., 2017, 117, 3479-3716.Narita, X. Y. Wang, X. Feng and K. Mullen, Chem. Soc. Rev., 2015, 44, 6616-6643.P. Lewtak and D. T. Gryko, Chem. Commun., 2012, 48, 10069-10086.K. S. Davis, A. L. Thompson and H. L. Anderson, J. Am. Chem. Soc., 2011, 133, 30-3.Hu, M. B. Thomas, W. A. Webre, A. Moss, R. G. W. Jinadasa, V. N. Nesterov, F. D’Souza and H. Wang, Angew. Chem. Int. Ed., 2020, 45 (132), 20250-20257.Moss, Y. Jang, J. Arvidson, V. N. Nesterov, F. D’Souza and H. Wang, Chem. Sci., 2022, 13, 9880 -9890.Moss, D. E. Nevonen, Y. Hu, V. N. Nesterov, V. Nemykin and H. Wang*, ACS Phys. Chem. Au, 2022, 2, 6, 468-481.

Impact of Pulsed Electric Field Ablation on His Bundle Conduction: A Preclinical Canine Study.

BACKGROUND Pulsed field ablation (PFA), as a non-thermal ablation modality, has received increasing attention. The aim of this study was to evaluate the effect of PFA upon His bundle via its implementation with different voltages on the maximum His bundle potential in canines, providing scientific basis for clinical application. MATERIAL AND METHODS Pulsed electrical field energy was delivered from a ablation catheter to the maximum His potential of 7 dogs, followed by a series of electrogram and histology assessments. RESULTS The baseline AH and HV intervals were 55.3±3.7 ms (range, 53.0-59.0 ms), and 34.9±1.3 ms (range, 34.0-36.0 ms), respectively, which were elevated to 65.0±5.4 ms (range, 59.0-70.0 ms) and 35.7±2.7 ms (range, 34.0-37.0 ms) after PFA. Before ablation and immediately after the recovery of third-degree AVB, the AH interval was prolonged (P<0.05) while the HV interval remained unchanged (P>0.05). After ablation, all 7 canines experienced transient third-degree AVB, with a voltage-dependent duration. Masson staining results revealed no apparent damage in His bundle cells. CONCLUSIONS Within a certain voltage range of pulse electric field, ablation of the maximum His potential in canines can result in transient third-degree AVB, providing a new route for guiding safe ablation of para-Hisian arrhythmia.

Effect of Cd on Structural, Spectral, Morphological and Dielectric Properties of Sr1-xCdxZn2Fe4O11 R-type Hexaferrites Synthesized via Sol-gel Technique

Sol–gel method was used to prepare Sr1-xCdxZn2Fe4O11 (x = 0.00, 0.02, 0.06, 0.1) R-type hexaferrite. The synthesized materials were sintered at 850oC and desired phase was obtained. X-ray diffraction analysis confirms that R-type hexaferrite exists only as a single phase. Using the Scherer formula, crystallite size for all of the prepared samples was found to be in the range of 10.39–12.62 nm. Crystallite size (D), the lattice parameters (a, c), and the cell volume (Vcell), d-spacing, bulk density, X-ray density, porosity, dislocation density and micro strain were determined in structural analysis. Fourier transform infrared spectroscopy method was used to identify the metal-oxygen vibrations at different locations. FT-IR verifies the presence of the Fe–O stretching vibration band at 743 and 867 cm−1. The typical grain size in surface morphology investigation ranges from 0.56 to 0.82 μm. Dielectric response of ferrite ceramic samples replaced with Cd2+ was investigated in the frequency range of 1 MHz–3 GHz. The AC conductivity rises with an increase in frequency because they are proportional to one another. This increasing tendency is effectively described by the theory of Maxwell-Wagner and Koop. Q-values remain constant as frequency rises and behaves independently of frequency as long as frequency reaches 1.7 GHz. These types of materials are utilized in high-frequency applications including frequency filters and resonant circuits. All of the magnetic properties determined by analyzing the M − H loops, including saturation magnetization (Ms), retentivity (Mr), and coercivity (Hc), exhibit an increasing trend as the substitution of Cd2+ rises. Ms (49.76–56.38 emu/g), Mr (15.82–18.30 emu/g) and Hc range from 203.20 Oe to 215.80 Oe. Grain size decreases cause arise in coercivity, which is caused by an enhancement in magneto-crystalline anisotropy. Overall results suggest that Cd2+ replaced R-type hexagonal ferrites are a great resource for longitudinal recording media; they have the potential to be used in a wide variety of electronic applications, including resonant circuits and high-frequency filters, security, detecting and switching.

P-Type ZnO Films Made by Atomic Layer Deposition and Ion Implantation.

Zinc oxide (ZnO) is a wide bandgap semiconductor that holds significant potential for various applications. However, most of the native point defects in ZnO like Zn interstitials typically cause an n-type conductivity. Consequently, achieving p-type doping in ZnO is challenging but crucial for comprehensive applications in the field of optoelectronics. In this work, we investigated the electrical and optical properties of ex situ doped p-type ZnO films. The p-type conductivity has been realized by ion implantation of group V elements followed by rapid thermal annealing (RTA) for 60 s or flash lamp annealing (FLA) on the millisecond time scale in nitrogen or oxygen ambience. The phosphorus (P)-doped ZnO films exhibit stable p-type doping with a hole concentration in the range of 1014 to 1018 cm-3, while antimony (Sb) implantation produces only n-type layers independently of the annealing procedure. Microstructural studies of Sb-doped ZnO show the formation of metallic clusters after ms range annealing and SbZn-oxides after RTA.

An incremental energy stimulation test to predict success in left bundle branch capture

Abstract Introduction Left bundle branch (LBB) stimulation is guided by fluoroscopic projections and electrocardiographic criteria limited by positional variations. Purpose To evaluate an incremental energy stimulation test (IEST) to optimize success. Methods Prospective, non-randomized experimental study for proof-of-concept analysis (N=23), consisting on: (i) stimulation at three locations at the high, middle and low right mid-ventricular septum (right oblique 30o); and (ii) continuous unipolar stimulation (lumenless fixed helix electrode) at each location with increasing outputs (2 volt x 0.5 ms up to 10 vol x 1.5 ms). The final position for lead penetration was made by the operator blinded to the results of the IEST. Results IEST shortened the S-LVAT (δ-S-LVAT) up to 6.4±5 ms (range 0 to 18 ms), 8±8 ms (range 0 to 36 ms) and 5.5±5 ms (range 0 to 20 ms) respectively for high, mid, and low sites (Figure, panel A and B). There was not observed any paired correlation between the magnitude of the δ-S-LVAT at the three different positions (Pearson 0.36, 0.12 and 0.22; p= 0.1, 0.6 and 0.4 respectively), suggesting that the δ-S-LVAT is site specific. The final position for lead penetration was medium in 17 cases vs low in 6 cases. The low-output S-LVAT interval at the final position before lead penetration was positively correlated with the final S-LVAT achieved after lead penetration (Pearson 0.44; p=0.04), but the magnitude of the correlation increased with the high-output S-LVAT interval (Pearson 0.57; p=0.006) suggesting a better prediction performance (Figure, panel C). A complex relationship was observed where higher δ-S-LVAT values were associated with shorter S-LVAT after penetration and final position of the lead. In fact, for cases with low-output S-LVAT interval &amp;gt; 100 ms, the δ-S-LVAT significantly correlated with S-LVAT after penetration and final position of the lead (Pearson -0.61; p=0.026). Conclusions IEST lead to a site-specific shortening of the S-LVAT, pointing to optimized positions for LBB pacing. The technique provides with additional diagnostic criteria to determine the better site for lead penetration.

Envelope Extraction Algorithm for Magnetic Resonance Sounding Signals Based on Adaptive Gaussian Filters

Magnetic resonance sounding is a geophysical method for quantitatively determining the state for groundwater storage that has gained international attention in recent years. However, the practical acquisition of magnetic resonance sounding signals, which are on the nanovolt scale, is susceptible to various types of interference, such as power-line harmonics, random noise, and spike noise. Such interference can degrade the quality of magnetic resonance sounding signals and, in severe cases, be completely drowned out by noise. This paper introduces an adaptive Gaussian filtering algorithm that is well-suited for handling intricate noise signals due to its adaptive solving characteristics and iterative sifting approach. Notably, the algorithm can process signals without relying on prior knowledge. The adaptive Gaussian filtering algorithm is applied for the envelope extraction of noisy magnetic resonance sounding signals, and the reliability and effectiveness of the method are rigorously validated. The simulation results reveal that, even under strong noise interference (with original signal-to-noise ratios ranging from −7 dB to −25 dB), the magnetic resonance sounding signal obtained after algorithmic processing is compared to the ideal signal, with 16 sets of data statistics, and the algorithm ensures an initial amplitude uncertainty within 4nV and restricts the uncertainty of the relaxation time within a 6 ms range. The signal-to-noise ratio can be boosted by up to 53 dB. The comparative assessments with classical algorithms such as empirical mode decomposition and the harmonic modeling method confirm the superior performance of the adaptive Gaussian filtering algorithm. The processing of the field data also fully proved the practical application effects of the algorithm.

Influences of divalent ion substitution on the magnetic and dielectric properties of W-type barium ferrite

Abstract Saturation magnetization, magneto-crystalline anisotropy field and dielectric properties are closely related to microwave devices applied at different frequencies. For regulating the magnetic and dielectric properties of W-type barium ferrites, single-phase BaMe 2Fe16O27 (Me = Fe, Mn, Zn, Ni, Co) with different Me ions were synthesized by the high-temperature solid-state method. The saturation magnetization (M s) range from 47.77 emu/g to 95.34 emu/g and the magnetic anisotropy field (H a) range from 10700.60 Oe to 13739.57 Oe, depending on the type of cation substitution in the hexagonal lattice. The dielectric permittivity and dielectric loss decrease with increasing frequency of the AC electric field in the low-frequency region, while they almost remain constant in the high-frequency region. The characteristics of easy regulation and preparation make it a potential candidate for use in microwave device applications.

Heat treatment and fiber drawing effect on the matrix structure and fluorescence lifetime of Er- and Tm-doped silica optical fibers

We investigate the influence of the optical fiber fabrication process on the fluorescence lifetime of Er3+ and Tm3+ ions. Optical fiber preforms were prepared using the MCVD method combined with Al2O3 nanoparticle doping. The preforms were subjected to various fabrication processes, such as preform elongation, fiber drawing, and heat treatment. The matrix structure of the preforms and fibers was studied by XRD and TEM. The fluorescence lifetime was measured. The fabrication processes caused the dissolution of the doped Al2O3 nanoparticles and a significant decrease of fluorescence lifetime of Tm3+ ions, from 875 µs in the preform down to 610 µs in the fiber, whereas no significant effect was observed for Er3+ ions, with fluorescence lifetime in the 9.6–10.2 ms range.

Hyperspectral image dynamic range reconstruction using deep neural network-based denoising methods

Hyperspectral (HS) measurement is among the most useful tools in agriculture for early disease detection. However, the cost of HS cameras that can perform the desired detection tasks is prohibitive-typically fifty thousand to hundreds of thousands of dollars. In a previous study at the Agricultural Research Organization’s Volcani Institute (Israel), a low-cost, high-performing HS system was developed which included a point spectrometer and optical components. Its main disadvantage was long shooting time for each image. Shooting time strongly depends on the predetermined integration time of the point spectrometer. While essential for performing monitoring tasks in a reasonable time, shortening integration time from a typical value in the range of 200 ms to the 10 ms range results in deterioration of the dynamic range of the captured scene. In this work, we suggest correcting this by learning the transformation from data measured with short integration time to that measured with long integration time. Reduction of the dynamic range and consequent low SNR were successfully overcome using three developed deep neural networks models based on a denoising auto-encoder, DnCNN and LambdaNetworks architectures as a backbone. The best model was based on DnCNN using a combined loss function of ℓ2\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\ell _{2}$$\\end{document} and Kullback–Leibler divergence on images with 20 consecutive channels. The full spectrum of the model achieved a mean PSNR of 30.61 and mean SSIM of 0.9, showing total improvement relatively to the 10 ms measurements’ mean PSNR and mean SSIM values by 60.43% and 94.51%, respectively.

A Bi-GRU-attention neural network to identify motor units from high-density surface electromyographic signals in real time.

To utilize surface electromyographics (sEMG) for control purposes, it is necessary to perform real-time estimation of the neural drive to the muscles, which involves real-time decomposition of the EMG signals. In this paper, we propose a Bidirectional Gate Recurrent Unit (Bi-GRU) network with attention to perform online decomposition of high-density sEMG signals. The model can give different levels of attention to different parts of the sEMG signal according to their importance using the attention mechanism. The output of gradient convolutional kernel compensation (gCKC) algorithm was used as the training label, and simulated and experimental sEMG data were divided into windows with 120 sample points for model training, the sampling rate of sEMG signal is 2048 Hz. We test different attention mechanisms and find out the ones that could bring the highest F1-score of the model. The simulated sEMG signal is synthesized from Fuglevand method (J. Neurophysiol., 1993). For the decomposition of 10 Motor Units (MUs), the network trained on simulated data achieved an average F1-score of 0.974 (range from 0.96 to 0.98), and the network trained on experimental data achieved an average F1-score of 0.876 (range from 0.82 to 0.97). The average decomposition time for each window was 28 ms (range from 25.6 ms to 30.5 ms), which falls within the lower bound of the human electromechanical delay. The experimental results show the feasibility of using Bi-GRU-Attention network for the real-time decomposition of Motor Units. Compared to the gCKC algorithm, which is considered the gold standard in the medical field, this model sacrifices a small amount of accuracy but significantly improves computational speed by eliminating the need for calculating the cross-correlation matrix and performing iterative computations.

MRI T2 mapping assessment of T2 relaxation time in desmoid tumors as a quantitative imaging biomarker of tumor response: preliminary results.

Because size-based imaging criteria poorly capture biologic response in desmoid-type fibromatosis (DF), changes in MRI T2 signal intensity are frequently used as a response surrogate, but remain qualitative. We hypothesized that absolute quantification of DF T2 relaxation time derived from parametric T2 maps would be a feasible and effective imaging biomarker of disease activity. This IRB-approved retrospective study included 11 patients with DF, managed by observation or systemic therapy, assessed by 3T MRI. Tumor maximum diameter, volume, and T2-weighted signal intensity were derived from manual tumor segmentations. Tumor:muscle T2 signal ratios were recorded. Two readers measured tumor T2 relaxation times using a commercial T2 scanning sequence, manual ROI delineation and commercial calculation software enabling estimation of reader reliability. Objective response rates based on RECIST1.1 and best responses were compared between size-based and signal-based parameters. Median patient age was 52.6 years; 8 subjects were female (73%). Nine patients with longitudinal assessments were followed for an average of 314 days. Median baseline tumor diameter was 7.2 cm (range 4.4 - 18.2 cm). Median baseline T2 was 65.1 ms (range 40.4 - 94.8 ms, n=11); median at last follow-up was 44.3 ms (-32% from baseline; range 29.3 - 94.7 ms, n=9). T2 relaxation times correlated with tumor:muscle T2 signal ratios, Spearman p=0.78 (p<0.001). T2 mapping showed high inter-reader reliability, ICC=0.84. The best response as a percentage change in T2 values was statistically significant (mean -17.9%, p=0.05, paired t-test) while change in diameter was not (mean -8.9%, p=0.12). Analysis of T2 relaxation time maps of DF may offer a feasible quantitative biomarker for assessing the extent of response to treatment. This approach may have high inter-reader reliability.

Activation time at left ventricular pacing site (QLV) in relation to actual site of latest activation; effect on response to cardiac resynchronization therapy

Abstract Background Among techniques to improve CRT efficacy, longer QLV (activation time at the left ventricular (LV) pacing site (LVPS)) has been proposed to correlate to response to cardiac resynchronization therapy (CRT), supporting that pacing close to the latest LV electrically activated site (LEAS) improves CRT efficacy. A QLV cut-off of &amp;gt; 95 ms has been proposed, however, predictive value was modest. This may be because LEAS was not identified, and empirically delivered leads may have missed it (described by a longer interval QLEAS (activation time at LEAS) to QLV. Purpose We compared QLEAS to QLV, and assessed effect of the interval QLEAS-QLV, on response to CRT. Methods We studied patients who had received CRT for Class I or Class IIa indications, regardless of CRT response, at 5 European sites. LV lead placement, device programming and follow up (FU) followed physician preference and site protocol. All patients had clinical FU 6-12 months post-implant, including echocardiographic study. CRT non-response was defined as LV end-systolic volume (LVESV) reduction of &amp;lt;15%. Patients underwent noninvasive 3D electrical activation mapping and torso CT 6-24 months post-implant. QLV and QLEAS were assessed from the noninvasive activation map in a blinded core lab. Logistic regression modelling was conducted for QLV and the interval QLEAS-QLV against CRT response, and the optimal cut-off points were calculated. Results Of 111 patients (age 64±11 years (mean±SD), 74% male, 98% LBBB, QRS duration 172±21 ms, baseline LVEF 28±6%, LVESV 183±87 mL, implant duration 12±5 months, 31%/69% NYHA Class II/III, 38% ischemic heart disease), 67% responded at 10±3 months post-implant. QLV overall was 97±23 ms (range 42-148 ms), 103±21 ms for responders and 83±22 for non- responders (p&amp;lt;0.001), QLEAS was 109±19 ms (range 66-150 ms), 109±20 ms for responders and 110±19 ms for non- responders (p=0.74). QLEAS-QLV overall was 13±18 ms (range 0-120 ms), 6±10 ms for responders and 27±22 ms for non-responders (p&amp;lt;0.001) (Figure 1). Optimal cut-off point for QLV was 85 ms with sensitivity 0.89, specificity 0.57 and an AUC of 0.742 (95% CI: 0.637- 0.846). Optimal cut-off point for QLEAS-QLV was 6 ms (sensitivity 0.77, specificity 0.95, AUC 0.901 (95% CI: 0.844-0.957) (Figure 1). The AUC of QLV cut-off and QLEAS-QLV cut-off differed significantly (p&amp;lt;0.001). 18/111 patients (16%) were non-responders despite a QLV≥85 ms, whereas 2 patients (2%) were non-responders despite a QLEAS-QLV≤6 ms. Conclusion QLEAS has greater discriminatory power than a QLV cut-off of 85 ms to separate CRT responders from non-responders in patients with LBBB and long QRS duration. QLV guided LV lead placement without prior knowledge of the latest LV activation in individual patients will miss the ideal LV pacing site in 16% of cases. Using noninvasive 3D global mapping to identify LEAS pre-CRT implant and directing LV lead placement to within 6 ms of this may improve CRT efficacy.Figure 1

Self-healable stretchable printed electronic cryogels for in-vivo plant monitoring

A key challenge in bioelectronics is to establish and improve the interface between electronic devices and living tissues, enabling a direct assessment of biological systems. Sensors integrated with plant tissue can provide valuable information about the plant itself as well as the surrounding environment, including air and soil quality. An obstacle in developing interfaces to plant tissue is mitigating the formation of fibrotic tissues, which can hinder continuous and accurate sensor operation over extended timeframes. Electronic systems that utilize suitable biocompatible materials alongside appropriate fabrication techniques to establish plant-electronic interfaces could provide for enhanced environmental understanding and ecosystem management capabilities. To meet these demands, this study introduces an approach for integrating printed electronic materials with biocompatible cryogels, resulting in stable implantable hydrogel-based bioelectronic devices capable of long-term operation within plant tissue. These inkjet-printed cryogels can be customized to provide various electronic functionalities, including electrodes and organic electrochemical transistors (OECTs), that exhibit high electrical conductivity for embedded conducting polymer traces (up to 350 S/cm), transconductance for OECTs in the mS range, a capacitance of up to 4.2 mF g−1 in suitable structures, high stretchability (up to 330% strain), and self-healing properties. The biocompatible functionalized cryogel-based electrodes and transistors were successfully implanted in plant tissue, and ionic activity in tomato plant stems was collected for over two months with minimal scar tissue formation, making these cryogel-based printed electronic devices excellent candidates for continuous, in-situ monitoring of plant and environmental status and health.

Done in 65 ms: Express Visuomotor Responses in Upper Limb Muscles in Rhesus Macaques.

How rapidly can the brain transform vision into action? Work in humans has established that the transformation for visually-guided reaching can be remarkably rapid, with the first phase of upper limb muscle recruitment, the express visuomotor response, beginning within less than 100 ms of visual target presentation. Such short-latency responses limit the opportunities for extensive cortical processing, leading to the hypothesis that they are generated via the subcortical tecto-reticulo-spinal pathway. Here, we examine whether nonhuman primates (NHPs) exhibit express visuomotor responses. Two male macaques made visually-guided reaches in a behavioral paradigm known to elicit express visuomotor responses in humans, while we acquired intramuscular recordings from the deltoid muscle. Across several variants of this paradigm, express visuomotor responses began within 65 ms (range: 48-91 ms) of target presentation. Although the timing of the express visuomotor response did not co-vary with reaction time, larger express visuomotor responses tended to precede shorter latency reaches. Further, we observed that the magnitude of the express visuomotor response could be muted by contextual context, although this effect was quite variable. Overall, the response properties in NHPs resemble those in humans. Our results establish a new benchmark for visuomotor transformations underlying visually-guided reaches, setting the stage for experiments that can directly compare the role of cortical and subcortical areas in reaching when time is of the essence.

High power laser heating of nuclear ceramics for the generation of controlled spatiotemporal gradients

The use of high-power lasers to reach the high temperatures typical for off-normal conditions in nuclear reactor fuel or to determine its properties at high temperature is a relevant and proven technique in the nuclear research community. Conducting studies at high temperature with full control in space and time of the thermal gradients is, however, a challenge. In this paper, we present a combination of methodologies, experiments, and models to drive nuclear fuel samples in thermal conditions relevant to the study of nuclear fuel materials. Based on the use of high-power (kW) lasers with beam shaping and temporal laser control, our experimental approach allows one to heat depleted UO2 samples and obtain precise control of the temporal gradients, in the ms range, and spatial gradients, in the 100 μm range. The coupling with numerical simulations allows one to determine the temperature distribution in the depth of the sample and to develop a thermo-mechanical interpretation of the results. We will present the methodology allowing one to properly compare experimental and simulation results by taking into account the optical response of the instrumentation, the laser–UO2 interaction, and the resulting heat source term. We will show that we can express the heat source term resulting from the laser loading either by an analytical description or statistically based on Monte-Carlo simulation. A fairly good agreement between the recorded temperature and the simulation results is shown. The presented methodology can be extended to other materials with a proper choice of laser wavelength and instrumentation based on the optical properties of the investigated material.

Effects on the timing of left ventricular pressure rise when pacing the right ventricular free wall in cardiac resynchronization therapy

Abstract Funding Acknowledgements Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Norwegian Research Council. Background/Introduction The timing of left ventricular pressure rise (Td) is associated with dispersion of regional work distribution and prolongs with dyssynchrony and dyssynergistic contractions. Synergistic contractions shorten Td and result from effective biventricular pacing (BIVP). Attempts have been made to optimize right ventricular (RV) lead position with septal lead placement away from the apex. In this study we attempted to study the effects from RV free wall (RVfw) compared to septal/ apical RV (RVsept) lead positioning on Td. Purpose RVfw pacing results in activation of RVfw before LV activation with a delay that may hamper the myocardial synergy resulting from biventricular pacing. This effect has not yet been demonstrated and may play an important role to understand non-response to CRT. Methods 9 mongrel dogs were included in the study and handled according to ethics committee approved protocol/GLP. Pacing electrodes were placed epicardial on the left atrial appendage, the RVfw and LV, and endocardial in the septum. Pressure was measured with a Micro-tip pressure sensor (Millar Inc.) in the LV. BIVP was performed from LV combined with RVsept or RVfw. Td was measured from 10 consecutive beats. Mixed models were utilized for the repeated measurements. Results The average Td with BiVP-RVfw, BIVP-RVsept and LV pacing only was 116ms (95% CI: 110, 122), 114ms (95% CI: 108, 120), and 118ms (95% CI: 112, 124) respectively (p&amp;lt;0.001). BiVP with RVsept shortened Td by 4.1 ms (95% confidence interval (CI): -5.3, -2.9, p&amp;lt;0.001), whereas BiVP with RVfw pacing location shorten Td by 1.8 ms (95% CI: -2.8, -0.8, p&amp;lt;0.001), compared to LVP. The SD from 10 beats was on average 0.8ms (range 0-1.6ms). Conclusion(s) Myocardial Synergy with shortening of Td compared to LV only pacing was demonstrated with BIVP regardless of RV position. The synergistic effect from BIVP is more pronounced with BIVP-RVsept than from BIVP-RVfw. RV lead position may play an important role in cardiac resynchronization therapy that can be revealed when measuring the time-course of LV pressure rise.

PO-02-014 IMPACT OF RIGHT VENTRICULAR ELECTRICAL ACTIVATION (INTRINSIC AND PACED) IN HEART FAILURE PATIENTS WITH LBBB

The appropriately timed incorporation of the intrinsic right bundle branch (RBB) conduction during biventricular (RV & LV) pacing – “triple fusion”- may improve electrical resynchronization and response to CRT. However, the relative contribution of these wavefronts, optimal programming, and impact upon left ventricular activation remains poorly understood. To characterize intrinsic RBB and paced RV activation in heart failure patients with LBBB. CRT Patients with Strauss-type LBBB were studied. Right ventricular electrical activation was estimated from the onset of the r wave to the nadir of the S wave (rS interval) in leads V1 and V2. QRS duration was taken as the earliest onset to the terminal deflection in any lead. Paced QRS was measured during RV only pacing and nominal BiV (BiVNom; paced and sensed AV delay of 140/110 ms). The optimal AV delay was determined by the narrowest QRS duration achieved during simultaneous BiV pacing (BiVOpt) while adjusting the paced AV delay from 60% to 95% of the PR interval (in increments of 5%). This protocol was repeated while withholding RV pacing (LV-onlyOpt). All measurements were performed in each patient. Thirty patients (53% Male, 33% ICM, 68±8 yrs, EF 24±7%, qRV 25±8 ms, qLV 123±21 ms, and QRSd 170±18 ms) were evaluated. The PR interval was 208±39 ms (range 117-328 ms). The qlV/ QRS was 73±9%, indicating optimized LV lead position. Compared to BiVNom, BiVOpt was achieved at longer AVD (80±7% vs 56±7% of PR interval) but resulted in more rapid RBB electrical activation (59±14 ms vs 90±20 ms) and narrower QRS duration (130±13 ms vs 146±16 ms); all P < 0.05 vs BiVNom. Withholding RV pacing (LV-onlyOpt) did not impact RBB activation or AV delay programming compared to BiVOpt, but still reduced QRS duration compared to BiVNom (139±14 ms vs 146±16 ms; P<0.05). Incorporation of RV pacing during biventricular pacing with longer AVD programming facilitates intrinsic RBB conduction to improve electrical resynchronization without committing the LV to this wavefront.

Fast Na+ ion dynamics in the Nb5+ bearing NaSICON Na3+x−zNbzZr2−zSi2+xP1−xO12 as probed by 23Na NMR and conductivity spectroscopy

NaSICON-type (Na superionic conductor, Na1+yZr2SiyP3−yO12, 0 < y < 3) represent a class of fast Na+ ion conductors with bulk ion conductivities in the mS range near room temperature. Starting from Na3Zr2(SiO4)2(PO4), i.e., from y = 2, we investigated the change in ion transport parameter when x in Na3+xZr2Si2+xP1−xO12 is increased from 0 to 0.4 and Nb5+ is substituted for Zr4+ according to Na3+x−zNbzZr2−zSi2+xP1−xO12 (z = 0.04). The later might be beneficial also to change the transport properties in or near the grain boundary regions of our polycrystalline samples. To detect such changes, we used low-temperature conductivity and electric modulus spectroscopy to differentiate between the total and the bulk (intragrain) electrical responses. However, the main purpose of the present study is to corroborate the extraordinarily high bulk ionic conductivity of approximately 7.3 mS cm−1 (x = 0.4 and z = 0.04, room temperature) by diffusion-controlled 23Na NMR spin-lattice relaxation measurements. Indeed, such experiments directly sense the 23Na spin-fluctuations at the nuclear sites as a result of the fast intragrain motional processes. Both methods, nuclear and non-nuclear, point to a mean activation energy of 0.3 eV for Na+ exchange among the multiple sites in the NaSICON framework. In addition, NMR reveals local barriers characterized by activation energies as low as 0.1 eV. Altogether, from a dynamic point of view, Na3.36Nb0.04Zr1.96Si2.4P0.6O12 turned out to be indeed a very promising candidate for the breakneck development of Na-based all-solid-state battery applications.