A comparative study of low voltage, low contrast cerebral computed tomography angiography with iterative reconstruction and conventional cerebral computed tomography angiography

BACKGROUND

Cerebral computed tomography angiography (CTA) has revolutionized the diagnosis of neurovascular emergencies. Strategies to reduce radiation, a concern for cancer, involve tube voltage and current reduction but with increased noise and inferior image quality. Hence, the objective of the study was to evaluate the quality of images obtained through low-dose radiation and low-contrast volume CTA with an iterative reconstruction (IR) technique versus standard CTA without IR.

METHODS

This prospective trial involved 100 adults requiring cerebral CTA for cerebrovascular diseases. They were split into two groups: one with 120 kVp tube voltage and 80 mL contrast using filtered back projection, and the other with 80 kVp and 30 mL contrast with IR. Evaluation criteria included attenuation values, signal-to-noise ratio, contrast-to-noise ratio, and subjective assessments.

RESULTS

Compared to 120 kVp, 80 kVp showed higher vessel attenuation in the internal (272.91 ± 30.59 vs 405.52 ± 53.08; p < .001) and middle cerebral artery (247.55 ± 29.84 vs 372.55 ± 49.02; p < .001) regions. Brain parenchymal attenuation at the centrum semiovale was lower with 80 kVp (29.12 ± 1.87 vs 24.78 ± 2.94; p < .001), accompanied by higher noise. Signal-to-noise ratio (p < .001) and contrast-to-noise ratio (p < .05) were lower at 80 kVp. Image quality didn't significantly differ, and radiation exposure reduced significantly by 70% in the 80 kVp group, suggesting its diagnostic feasibility.

CONCLUSIONS

The 80 kVp protocol for CTA of the cerebral vessels combined with lower contrast volume produces images with similar image quality with significant radiation effective dose and total iodine dose reduction. The 80 kVp protocol holds significant promise for replacing the standard 120 kVp protocol in cerebral CTA.

Dielectric Design of High Dielectric Constant Poly(Urea-Urethane) Elastomer for Low-Voltage High-Mobility Intrinsically Stretchable All-Solution-Processed Organic Transistors

Stretchable organic transistors for skin-like biomedical applications require low-voltage operation to accommodate limited power supply and safe concerns. However, most of the currently reported stretchable organic transistors operate at relatively high voltages. Decreasing their operational voltage while keeping the high mobility still remains a key challenge. Here, the study presents a new dielectric design to achieve high-dielectric constant poly(urea-urethane) (PUU) elastomer, by incorporating a flexible small-molecular diamine crosslinking agent 4-aminophenyl disulfide (APDS) into the main chain of (poly (propylene glycol), tolylene 2,4-diiso-cyanate terminated) (PPG-TDI). Compared with commercial elastomers, the PUU elastomer as dielectric of the stretchable organic transistors shows the outstanding advantages including lower surface roughness (0.33 nm), higher adhesion (45.18 nN), higher dielectric constant (13.5), as well as higher stretchability (896%). The PUU dielectric enables the intrinsically stretchable, all-solution-processed organic transistor to operate at a low operational voltage down to -10 V, while preserving a substantial mobility of 1.39 cm2  V-1  s-1 . Impressively, the transistor also demonstrates excellent electrical stability under repeated switching of 10 000 cycles, and remarkable mechanical robustness when stretched up to 100%. The work opens up a new molecular engineering strategy to successfully realize low-voltage high-mobility stretchable all-solution-processed organic transistors.

Design of a 0.5 V Chopper-Stabilized Differential Difference Amplifier for Analog Signal Processing Applications

This paper presents a low-voltage low-power chopper-stabilized differential difference amplifier (DDA) realized using 40 nm CMOS technology. Operating with a supply voltage of 0.5 V, a three-stage DDA has been employed to achieve an open-loop gain of 89 dB, while consuming just 0.74 μW of power. The proposed DDA incorporates feed-forward frequency compensation and a Type II compensator to achieve pole-zero cancellation and damping factor control. The DDA has a unity-gain bandwidth (UGB) of 170 kHz, a phase margin (PM) of 63.98°, and a common-mode rejection ratio (CMRR) of up to 100 dB. This circuit can effectively drive a 50 pF capacitor in parallel with a 300 kΩ resistor. The use of the chopper stabilization technique effectively mitigates the offset and 1/f noise. The chopping frequency of the chopper modulator is 5 kHz. The input noise is 245 nV/sqrt (Hz) at 1 kHz, and the input-referred offset under Monte Carlo cases is only 0.26 mV. Such a low-voltage chopper-stabilized DDA will be very useful for analog signal processing applications. Compared to the reported chopper DDA counterparts, the proposed DDA is regarded as that with one of the lowest supply voltages. The proposed DDA has demonstrated its effectiveness in tradeoff design when dealing with multiple parameters pertaining to power consumption, noise, and bandwidth.

Solution-Processed Polymer Dielectric Interlayer for Low-Voltage, Unipolar n-Type Organic Field-Effect Transistors

The integration of organic electronic circuits into real-life applications compels the fulfillment of a range of requirements, among which the ideal operation at a low voltage with reduced power consumption is paramount. Moreover, these performance factors should be achieved via solution-based fabrication schemes in order to comply with the promise of cost- and energy-efficient manufacturing offered by an organic, printed electronic technology. Here, we propose a solution-based route for the fabrication of low-voltage organic transistors, encompassing ideal device operation at voltages below 5 V and exhibiting n-type unipolarization. This process is widely applicable to a variety of semiconducting and dielectric materials. We achieved this through the use of a photo-cross-linked, low-k dielectric interlayer, which is used to fabricate multilayer dielectric stacks with areal capacitances of up to 40 nF/cm2 and leakage currents below 1 nA/cm2. Because of the chosen azide-based cross-linker, the dielectric promotes n-type unipolarization of the transistors and demonstrated to be compatible with different classes of semiconductors, from conjugated polymers to carbon nanotubes and low-temperature metal oxides. Our results demonstrate a general applicability of our unipolarizing dielectric, facilitating the implementation of complementary circuitry of emerging technologies with reduced power consumption.

Design and Analysis of a Low-Voltage VCO: Reliability and Variability Performance

This paper investigates an adaptive body biasing (ABB) circuit to improve the reliability and variability of a low-voltage inductor-capacitor (LC) voltage-controlled oscillator (VCO). The ABB circuit provides VCO resilience to process variability and reliability variation through the threshold voltage adjustment of VCO's transistors. Analytical equations considering the body bias effect are derived for the most important relations of the VCO and then the performance is verified using the post-layout simulation results. Under a 0.16% threshold voltage shift, the sensitivity of the normalized phase noise and transconductance of the VCO with the ABB circuit compared to the constant body bias (CBB) decreases by around 8.4 times and 3.1 times, respectively. Also, the sensitivity of the normalized phase noise and transconductance of the proposed VCO under 0.16% mobility variations decreases by around 1.5 times and 1.7 times compared to the CBB, respectively. The robustness of the VCO is also examined using process variation analysis through Monte Carlo and corner case simulations. The post-layout results in the 180 nm CMOS process indicate that the proposed VCO draws a power consumption of only 398 µW from a 0.6 V supply when the VCO frequency is 2.4 GHz. It achieves a phase noise of -123.19 dBc/Hz at a 1 MHz offset and provides a figure of merit (FoM) of -194.82 dBc/Hz.

Rationally Designing High-Performance Versatile Organic Memristors through Molecule-Mediated Ion Movements

Organic memory has attracted tremendous attention for next-generation electronic elements for the molecules' striking ease of structural design. However, due to them being hardly controllable and their low ion transport, it is always essential and challenge to effectively control their random migration, pathway, and duration. There are very few effective strategies, and specific platforms with a view to molecules with specific coordination-groups-regulating ions have been rarely reported. In this work, as a generalized rational design strategy, the well-known tetracyanoquinodimethane (TCNQ) is introduced with multiple coordination groups and small plane structure into a stable polymers framework to modulate Ag migration and then achieve high-performance devices with ideal productivity, low operation voltage and power, stable switching cycles, and state retention. Raman mapping demonstrates that the migrated Ag can specially coordinate with the embedded TCNQ molecules. Notably, the TCNQ molecule distribution can be modulated inside the polymer framework and regulate the memristive behaviors through controlling the formed Ag conductive filaments (CFs) as demonstrated by Raman mapping, in situ conductive atomic force microscopy (C-AFM), X-ray diffraction (XRD) and depth-profiling X-ray photoelectron spectroscopy (XPS). Thus the controllable molecule-mediated Ag movements show its potential in rationally designing high-performance devices and versatile functions and is enlightening in constructing memristors with molecule-mediated ion movements.

Low-Voltage Solution-Processed Zinc-Doped CuI Thin Film Transistors with NOR Logic and Artificial Synaptic Function

Low-voltage Zn-doped CuI thin film transistors (TFTs) gated by chitosan dielectric were fabricated at a low temperature. The Zn-doped CuI TFT exhibited a more superior on/off current ratio than CuI TFT due to the substitution or supplementation of copper vacancies by Zn ions. The Zn-doped CuI films were characterized by scanning electron microscope, X-ray diffraction, and X-ray photoelectron spectroscopy. The Zn-doped CuI TFTs exhibited an on/off current ratio of 1.58 × 104, a subthreshold swing of 70 mV/decade, and a field effect mobility of 0.40 cm2V-1s-1, demonstrating good operational stability. Due to the electric-double-layer (EDL) effect and high specific capacitance (17.3 μF/cm2) of chitosan gate dielectric, Zn-doped CuI TFT operates at a voltage below -2 V. The threshold voltage is -0.2 V. In particular, we have prepared Zn-doped CuI TFTs with two in-plane gates and NOR logic operation is implemented on such TFTs. In addition, using the ion relaxation effect and EDL effect of chitosan film, a simple pain neuron simulation is realized on such a p-type TFTs for the first time through the bottom gate to regulate the carrier transport of the channel. This p-type device has promising applications in low-cost electronic devices, complementary electronic circuit, and biosensors.

Van der Waals Multilayer Heterojunction for Low-Voltage Organic RGB Area-Emitting Transistor Array

Organic light-emitting transistors (OLETs) have garnered considerable attention from academy and industry due to their potential applications in next-generation display technologies, multifunctional devices, and organic electrically pumped lasers. However, overcoming the trade-offs among power consumption, external quantum efficiency (EQE), and uniform area emission remains a long-standing issue for OLETs. Herein, a van der Waals multilayer heterojunction methodology is proposed to enhance the layer-to-layer interfacial interaction and contact, resulting in better dipole shielding, carrier transport, exciton recombination, and current density distribution. The prepared multilayer heterojunction OLET (MLH-OLET) array shows uniform and bright RGB area emission and low operating voltage (<30 V among the lowest applied voltage of reported lateral LETs). Additionally, a high brightness under area emission of 1060 cd m^-2 , a high EQE value of 0.85%, and a high loop stability (over 380 cycles, outperforming state-of-the-art OLETs) indicate that the proposed multilayer heterojunction is obviously superior to the reported lateral device configuration. The van der Waals multilayer heterojunction developed for the preparation of OLET arrays sufficiently meets the low-voltage, high-performance, and low-cost requirements of future display technologies.

Amplified sinus-P-wave analysis predicts outcomes of cryoballoon ablation in patients with persistent and long-standing persistent atrial fibrillation: A multicentre study

Introduction

Outcomes of catheter ablation for non-paroxysmal atrial fibrillation (AF) remain suboptimal. Non-invasive stratification of patients based on the presence of atrial cardiomyopathy (ACM) could allow to identify the best responders to pulmonary vein isolation (PVI).

Methods

Observational multicentre retrospective study in patients undergoing cryoballoon-PVI for non-paroxysmal AF. The duration of amplified P-wave (APW) was measured from a digitally recorded 12-lead electrocardiogram during the procedure. If patients were in AF, direct-current cardioversion was performed to allow APW measurement in sinus rhythm. An APW cut-off of 150 ms was used to identify patients with significant ACM. We assessed freedom from arrhythmia recurrence at long-term follow-up in patients with APW ≥ 150 ms vs. APW < 150 ms.

Results

We included 295 patients (mean age 62.3 ± 10.6), of whom 193 (65.4%) suffered from persistent AF and the remaining 102 (34.6%) from long-standing persistent AF. One-hundred-forty-two patients (50.2%) experienced arrhythmia recurrence during a mean follow-up of 793 ± 604 days. Patients with APW ≥ 150 ms had a significantly higher recurrence rate post ablation compared to those with APW < 150 ms (57.0% vs. 41.6%; log-rank p < 0.001). On a multivariable Cox-regression analysis, APW≥150 ms was the only independent predictor of arrhythmia recurrence post ablation (HR 2.03 CI_95% 1.28-3.21; p = 0.002).

Conclusion

APW duration predicts arrhythmia recurrence post cryoballoon-PVI in persistent and long-standing persistent AF. An APW cut-off of 150 ms allows to identify patients with significant ACM who have worse outcomes post PVI. Analysis of APW represents an easy, non-invasive and highly reproducible diagnostic tool which allows to identify patients who are the most likely to benefit from PVI-only approach.

Low voltage-guided ablation of posterior wall improves 5-year arrhythmia-free survival in persistent atrial fibrillation

INTRODUCTION

The posterior wall (PW) has been proposed as a standard target for ablation beyond pulmonary vein antral isolation (PVI) in patients with persistent atrial fibrillation (AF). However, studies have shown inconsistent outcomes with the addition of PW ablation. The presence or absence of low voltage on the PW may explain these inconsistencies. We evaluated whether PW ablation based on the presence or absence of low voltage improves long-term arrhythmia-free outcomes.

METHODS

We retrospectively reviewed 5-year follow-up in 152 consecutive patients who received either standard ablation (SA) with PVI alone or PVI + PW ablation (PWA) based on physician discretion (n = 77) or voltage-guided ablation (VGA) with PVI and addition of PWA only if low voltage was present on the PW (n = 75).

RESULTS

The two groups were well matched for baseline characteristics. At 5-year follow-up, 64% of patients receiving VGA were atrial tachyarrhythmia (AT)/AF free compared to 34% receiving SA (HR 0.358 p < .005). PWA had similar AF recurrence in SA and VGA groups (0.30 vs. 0.27 p = .96) but higher AT recurrence when comparing SA and VGA groups (0.39 vs. 0.15 p = .03). In multivariate analysis, both VGA and PWA predicted AF arrhythmia-free survival (HR 0.33, p = .001 and HR 0.20, p = .008, respectively). For AT, VGA predicted arrhythmia-free survival (HR 0.22, p = .028), while PWA predicted AT recurrence (HR 4.704, p = .0219).

CONCLUSION

VGA of the posterior wall ablation beyond PVI in persistent AF significantly improves long-term arrhythmia-free survival when compared with non-voltage-guided ablation. PW ablation without voltage-guidance reduced AF recurrence but at the cost of a higher incidence of AT.

Validation of an electrocardiographic marker of low voltage areas in the right ventricular outflow tract in patients with idiopathic ventricular arrhythmias

BACKGROUND

Previous studies have reported the presence of subtle abnormalities in the right ventricular outflow tract (RVOT) in patients with apparently normal hearts and ventricular arrhythmias (VAs) from the RVOT, including the presence of low voltage areas (LVAs). This LVAs seem to be associated with the presence of ST-segment elevation in V1 or V2 leads at the level of the 2nd intercostal space (ICS).

OBJECTIVE

Our aim was to validate an electrocardiographic marker of LVAs in the RVOT in patients with idiopathic outflow tract VAs.

METHODS

A total of 120 patients were studied, 84 patients referred for ablation of idiopathic VAs with an inferior axis by the same operator, and a control group of 36 patients without VAs. Structural heart disease including arrhythmogenic right ventricular cardiomyopathy was ruled out in all patients. An electrocardiogram was performed with V1-V2 at the 2nd ICS, and ST-segment elevation ≥1 mm and T-wave inversion beyond V1 were assessed. Bipolar voltage map of the RVOT was performed in sinus rhythm (0.5-1.5 mV color display). Areas with electrograms <1.5 mV were considered LVAs, and their presence was assessed. We compared three groups, VAs from the RVOT (n = 66), VAs from the LVOT (n = 18) and Control group (n = 36). ST-elevation, T-wave inversion and left versus right side of the VAs were tested as predictors of LVAs, respective odds ratio (ORs) (95% confidence interval [CI]) and p values, were calculated with univariate logist regression. Variables with a p < .005 were included in the multivariate analysis.

RESULTS

ST-segment elevation, T-wave inversion and LVAs were present in the RVOT group, LVOT group and Control group as follows: (62%, 17%, and 6%, p < .0001), (33%, 29%, and 0%, p = .001) and (62%, 25%, and 14%, p < .0001). The ST-segment elevation, T-wave inversion and right-sided VAs were all predictors of LVAs, respective unadjusted ORs (95% CI), p values were, 32.31 (11.33-92.13), p < .0001, 4.137 (1.615-10.60), p = .003 and 8.200 (3.309-20.32), p < .0001. After adjustment, the only independent predictor of LVAs was the ST-segment elevation, with an adjusted OR (95% CI) of 20.94 (6.787-64.61), p < .0001.

CONCLUSION

LVAs were frequently present in patients with idiopathic VAs. ST-segment elevation was the only independent predictor of their presence.

Validating left atrial fractionation and low-voltage substrate during atrial fibrillation and sinus rhythm-A high-density mapping study in persistent atrial fibrillation

BACKGROUND

Low-voltage-substrate (LVS)-guided ablation for persistent atrial fibrillation (AF) has been described either in sinus rhythm (SR) or AF. Prolonged fractionated potentials (PFPs) may represent arrhythmogenic slow conduction substrate and potentially co-localize with LVS. We assess the spatial correlation of PFP identified in AF (PFP-AF) to those mapped in SR (PFP-SR). We further report the relationship between LVS and PFPs when mapped in AF or SR.

MATERIALS AND METHODS

Thirty-eight patients with ablation naïve persistent AF underwent left atrial (LA) high-density mapping in AF and SR prior to catheter ablation. Areas presenting PFP-AF and PFP-SR were annotated during mapping on the LA geometry. Low-voltage areas (LVA) were quantified using a bipolar threshold of 0.5 mV during both AF and SR mapping. Concordance of fractionated potentials (CFP) (defined as the presence of PFPs in both rhythms within a radius of 6 mm) was quantified. Spatial distribution and correlation of PFP and CFP with LVA were assessed. The predictors for CFP were determined.

RESULTS

PFPs displayed low voltages both during AF (median 0.30 mV (Q1-Q3: 0.20-0.50 mV) and SR (median 0.35 mV (Q1-Q3: 0.20-0.56 mV). The duration of PFP-SR was measured at 61 ms (Q1-Q3: 51-76 ms). During SR, most PFP-SRs (89.4 and 97.2%) were located within LVA (<0.5 mV and <1.0 mV, respectively). Areas presenting PFP occurred more frequently in AF than in SR (median: 9.5 vs. 8.0, p = 0.005). Both PFP-AF and PFP-SR were predominantly located at anterior LA (>40%), followed by posterior LA (>20%) and septal LA (>15%). The extent of LVA < 0.5 mV was more extensive in AF (median: 25.2% of LA surface, Q1-Q3:16.6-50.5%) than in SR (median: 12.3%, Q1-Q3: 4.7-29.4%, p = 0.001). CFP in both rhythms occurred in 80% of PFP-SR and 59% of PFP-AF (p = 0.008). Notably, CFP was positively correlated to the extent of LVA in SR (p = 0.004), but not with LVA in AF (p = 0.226). Additionally, the extent of LVA < 0.5 mV in SR was the only significant predictor for CFP, with an optimal threshold of 16% predicting high (>80%) fractionation concordance in AF and SR.

CONCLUSION

Substrate mapping in SR vs. AF reveals smaller areas of low voltage and fewer sites with PFP. PFP-SR are located within low-voltage areas in SR. There is a high degree of spatial agreement (80%) between PFP-AF and PFP-SR in patients with moderate LVA in SR (>16% of LA surface). These findings should be considered when substrate-based ablation strategies are applied in patients with the left atrial low-voltage substrate with recurrent persistent AF.

A Fully Integrated Low-Dropout Regulator with Improved Load Regulation and Transient Responses

A fully integrated low-dropout (LDO) regulator with improved load regulation and transient responses in 40 nm technology is presented in this paper. Combining adjustable threshold push-pull stage (ATPS) and master-slave power transistors topology, the proposed LDO maintains a three-stage structure within the full load range. The proposed structure ensures the steady-state performance of LDO and achieves 0.017 mV/mA load regulation. The ATPS consumes little quiescent current at light load current condition, and the turn-on threshold of the ATPS can be adjusted by a current source. Once the value of current source is set, the turn-on threshold is also determined. A benefit of the proposed structure is that the LDO can be stable from 0 to 100 mA load current with a maximum 100 pF parasitic load capacitance and a 0.7 pF compensation capacitor. It also shows good figure of merit (FOM) without an extra transient enhanced circuit. For the maximum 100 mA load transient with 100 ns edge time, the undershoot and overshoot are less than 33 mV. The dropout voltage of the regulator is 200 mV with input voltage of 1.1 V. The total current consumption of the LDO was 24.6 μA at no load.

Low-Voltage and Low-Power True-Single-Phase 16-Transistor Flip-Flop Design

A low-voltage and low-power true single-phase flip-flop that minimum the total transistor count by using the pass transistor logic circuit scheme is proposed in this paper. Optimization measures lead to a new flip-flop design with better various performances such as speed, power, energy, and layout area. Based on post-layout simulation results using the TSMC CMOS 180 nm and 90 nm technologies, the proposed design achieves the conventional transmission-gate-based flip-flop design with a 53.6% reduction in power consumption and a 63.2% reduction in energy, with 12.5% input data switching activity. In order to further the performance parameters of the proposed design, a shift-register design has been realized. Experimental measurements at 0.5 V/0.5 MHz show that this proposed design reduces power consumption by 47.3% while achieving a layout area reduction of 30.5% compared to the conventional design.

A Moisture-Resistant Soft Actuator with Low Driving Voltages for Haptic Stimulations in Virtual Games

Strong and robust stimulations to human skins with low driving voltages under high moisture working conditions are desirable for wearable haptic feedback applications. Here, a soft actuator based on the "air bubble" electret structure is developed to work in high-moisture environments and produce haptic sensations to human skin with low driving voltages. Experimentally, the water soaking and drying process has been conducted repeatedly for the first time and the 20th time to test the antimoisture ability of the actuator as it recovers its output force up 90 and 65% of the initial value, respectively. The threshold voltages for sensible haptic sensations for the fingertip and palm of volunteers have been characterized as 7 and 10 V, respectively. Furthermore, a demonstration example has been designed and conducted in a virtual boxing game to generate the designated haptic sensations according to the gaming conditions with an accuracy of 98% for more than 100 tests. As such, the design principle, performance characteristic, and demonstration example in this work could inspire various applications with improved reliability for wearable haptic devices.

Distribution of atrial low voltage induced by vein of Marshall ethanol infusion

INTRODUCTION

Systematic and quantitative descriptions of vein of Marshall (VOM)-induced tissue ablation are lacking. We sought to characterize the distribution of low voltage observed in the left atrium (LA) after VOM ethanol infusion.

METHODS AND RESULTS

The distribution of ethanol-induced low voltage was evaluated by comparing high-density maps performed before and after VOM ethanol infusion in 114 patients referred for atrial fibrillation ablation. The two most frequently impacted segments were the inferior portion of the ridge (82.5%) and the first half of the mitral isthmus (pulmonary vein side) (92.1%). Low-voltage absence in these typical areas resulted from inadvertent ethanol infusion in the left atrial appendage vein (n = 3), initial VOM dissection (n = 3), or a "no branches" VOM morphology (n = 1). Visible anastomosis of the VOM with roof or posterior veins more frequently resulted in low-voltage extension beyond typical areas, toward the entire left antrum (19.0% vs. 1.9%, p = .0045) or the posterior LA (39.7% vs. 3.8%, p < .001) but with a limited positive predictive value ranging from 29.4% to 43.5%. Ethanol-induced low voltage covered a median LA surface of 3.6% (1.9%-5.0%) and did not exceed 8% of the LA surface in 90% of patients.

CONCLUSION

VOM ethanol infusion typically locates at the inferior ridge and the adjacent half of the mitral isthmus. Low-voltage extensions can be anticipated but not guaranteed by the presence of visible anastomosis of the VOM with roof or posterior veins.

New Era of Electroceuticals: Clinically Driven Smart Implantable Electronic Devices Moving towards Precision Therapy

In the name of electroceuticals, bioelectronic devices have transformed and become essential for dealing with all physiological responses. This significant advancement is attributable to its interdisciplinary nature from engineering and sciences and also the progress in micro and nanotechnologies. Undoubtedly, in the future, bioelectronics would lead in such a way that diagnosing and treating patients' diseases is more efficient. In this context, we have reviewed the current advancement of implantable medical electronics (electroceuticals) with their immense potential advantages. Specifically, the article discusses pacemakers, neural stimulation, artificial retinae, and vagus nerve stimulation, their micro/nanoscale features, and material aspects as value addition. Over the past years, most researchers have only focused on the electroceuticals metamorphically transforming from a concept to a device stage to positively impact the therapeutic outcomes. Herein, the article discusses the smart implants' development challenges and opportunities, electromagnetic field effects, and their potential consequences, which will be useful for developing a reliable and qualified smart electroceutical implant for targeted clinical use. Finally, this review article highlights the importance of wirelessly supplying the necessary power and wirelessly triggering functional electronic circuits with ultra-low power consumption and multi-functional advantages such as monitoring and treating the disease in real-time.

Design and Fabrication of a Ka Band RF MEMS Switch with High Capacitance Ratio and Low Actuation Voltage

In this paper a high capacitance ratio and low actuation voltage RF MEMS switch is designed and fabricated for Ka band RF front-ends application. The metal-insulator-metal (MIM) capacitors is employed on a signal line to improve the capacitance ratio, which will not degrade the switch reliability. To reduce the actuation voltage, a low spring constant bending folding beam and bilateral drop-down electrodes are designed in the MEMS switch. The paper analyzes the switch pull-in model and deduces the elastic coefficient calculation equation, which is consistent with the simulation results. The measured results indicated that, for the proposed MEMS switch with a gap of 2 μm, the insertion loss is better than −0.5 dB and the isolation is more than −20 dB from 25 to 35 GHz with an actuation voltage of 15.8 V. From the fitted results, the up-state capacitance is 6.5 fF, down-state capacitance is 4.3 pF, and capacitance ratios is 162. Compared with traditional MEMS capacitive switches with dielectric material Si₃N₄, the proposed MEMS switch exhibits high on/off capacitance ratios of 162 and low actuation voltage.

Study on Cross-Coupled-Based Sensing Circuits for Nonvolatile Flip-Flops Operating in Near/Subthreshold Voltage Region

To date, most studies focus on complex designs to realize offset cancelation characteristics in nonvolatile flip-flops (NV-FFs). However, complex designs using switches are ineffective for offset cancelation in the near/subthreshold voltage region because switches become critical contributors to the offset voltage. To address this problem, this paper proposes a novel cross-coupled NMOS-based sensing circuit (CCN-SC) capable of improving the restore yield, based on the concept that the simplest is the best, of an NV-FF operating in the near/subthreshold voltage region. Measurement results using a 65 nm test chip demonstrate that with the proposed CCN-SC, the restore yield is increased by more than 25 times at a supply voltage of 0.35 V, compared to that with a cross-coupled inverter-based SC, at the cost of 18× higher power consumption.

Synthesis of Lead-Free CaTiO3 Oxide Perovskite Film through Solution Combustion Method and Its Thickness-Dependent Hysteresis Behaviors within 100 mV Operation

Perovskite is attracting considerable interest because of its excellent semiconducting properties and optoelectronic performance. In particular, lead perovskites have been used extensively in photovoltaic, photodetectors, thin-film transistors, and various electronic applications. On the other hand, the elimination of lead is essential because of its strong toxicity. This paper reports the synthesis of lead-free calcium titanate perovskite (CaTiO₃) using a solution-processed combustion method. The chemical and morphological properties of CaTiO₃ were examined as a function of its thickness by scanning electron microscopy, X-ray diffraction (XRD), atomic force microscopy, X-ray photoelectron spectroscopy, and ultraviolet–visible spectrophotometry. The analysis showed that thicker films formed by a cumulative coating result in larger grains and more oxygen vacancies. Furthermore, thickness-dependent hysteresis behaviors were examined by fabricating a metal-CaTiO₃-metal structure. The electrical hysteresis could be controlled over an extremely low voltage operation, as low as 100 mV, by varying the grain size and oxygen vacancies.

Low-Voltage Zones as the Atrial Fibrillation Substrates: Relationship With Initiation, Perpetuation, and Termination

Background: Low-voltage zones (LVZs) were usually targeted for ablation in atrial fibrillation (AF). However, its relationship with AF initiation, perpetuation, and termination remains to be studied. This study aimed to explore such relationships.

Methods: A total of 126 consecutive AF patients were enrolled, including 71 patients for AF induction protocol and 55 patients for AF termination protocol. Inducible and sustainable AF were defined as induced AF lasting over 30 and 300 s, respectively. Terminable AF was defined as those that could be terminated into sinus rhythm within 1 h after ibutilide administration. Voltage mapping was performed in sinus rhythm for all patients. LVZ was quantified as the percentage of the LVZ area (LVZ%) to the left atrium surface area.

Results: The rates of inducible, sustainable, and terminable AF were 29.6, 18.3, and 38.2%, respectively. Inducible AF patients had no significant difference in overall LVZ% compared with uninducible AF patients (10.2 ± 11.8 vs. 8.5 ± 12.6, p = 0.606), while sustainable and interminable AF patients had larger overall LVZ% than unsustainable (16.2 ± 11.5 vs. 0.5 ± 0.7, p < 0.001) and terminable AF patients (44.6 ± 26.4 vs. 26.3 ± 22.3, p < 0.05), respectively. The segmental LVZ distribution pattern was diverse in the different stages of AF. Segmental LVZ% difference was initially observed in the anterior wall for patients with inducible AF, and the septum was further affected in those with sustainable AF, and the roof, posterior wall, and floor were finally affected in those with interminable AF.

Conclusions: The associations between LVZ with AF initiation, perpetuation, and termination were different depending on its size and distribution.

Cardiac Amyloidosis with Discordant QRS Voltage between Frontal and Precordial Leads

Among the different types, immunoglobulin light chain (AL) cardiac amyloidosis is associated with the highest morbidity and mortality. The outcome, however, is significantly better when an early diagnosis is made and treatment initiated promptly. We present a case of cardiac amyloidosis with left ventricular hypertrophy criteria on the electrocardiogram. After 9 months of follow-up, the patient developed low voltage in the limb leads, while still maintaining the Cornell criteria for left ventricular hypertrophy as well. The relative apical sparing by the disease process, as well as decreased cancellation of the opposing left ventricular walls could be responsible for this phenomenon. The discordance between the voltage in the frontal leads and precordial leads, when present in conjunction with other findings, may be helpful in raising the clinical suspicion of cardiac amyloidosis.

High-kerbium oxide film prepared by sol-gel method for low-voltage thin-film transistor

In this work, high-dielectric-constant (high-k) erbium oxide（Er₂O₃）film is fabricated using the spin coating method, and annealed at a series of temperatures (from 400 °C to 700 °C). The effect of annealing temperature on the microstructural and electrical properties of Er₂O₃nanofilm is investigated. To demonstrate the applicability of the Er₂O₃film, the indium oxide (In₂O₃) thin film transistor (TFT)-based amorphous Er₂O₃dielectric film is fabricated at different temperatures. The TFT-based EO-600 shows a low-operating voltage and good electrical properties. The inverter demonstrates that the Er₂O₃nanofilm synthesized by the sol-gel method could be a promising candidate as the dielectric layer in a low-voltage electronic device.

A Case Report: Low Voltage Electric Injuries Culminating in Cardiac Arrest and Direct Lung Injury

Serious electrical injuries are rare but may have life-threatening consequences. Voltage exposure injuries are divided into low voltage injury (LVI) or high voltage injury (HVI). An LVI current can result in severe injury, depending on the length of exposure, the size of the individual, the cross-sectional area in contact with the electrical source, and environmental humidity.

The authors present a 31-year-old male with accidental electrocution with low voltage current and cardiopulmonary arrest. A detailed revision by organs and systems is presented.

LVI is uncommon and can occur with a variety of clinical presentations, rarely presenting with direct lung injury. Early recognition and support are the cornerstones of treatment.

Low-Voltage, Dual-Gate Organic Transistors with High Sensitivity and Stability toward Electrostatic Biosensing

High levels of performance and stability have been demonstrated for conjugated polymer thin-film transistors in recent years, making them promising materials for flexible electronic circuits and displays. For sensing applications, however, most research efforts have been focusing on electrochemical sensing devices. Here we demonstrate a highly stable biosensing platform using polymer transistors based on the dual-gate mechanism. In this architecture a sensing signal is transduced and amplified by the capacitive coupling between a low-k bottom dielectric and a high-k ionic elastomer top dielectric that is in contact with an analyte solution. The new design exhibits a high signal amplification, high stability under bias stress in various aqueous environments, and low signal drift. Our platform, furthermore, while responding expectedly to charged analytes such as the protein bovine serum albumin, is insensitive to changes of salt concentration of the analyte solution. These features make this platform a potentially suitable tool for a variety of biosensing applications.

Idiopathic Premature Ventricular Contractions From the Outflow Tract Display an Underlying Substrate That Can Be Unmasked by a Type 2 Brugada Electrocardiographic Pattern at High Right Precordial Leads

Background: Patients with premature ventricular contractions (PVCs) from the right ventricular outflow tract (RVOT) and apparently normal hearts, can have ST elevation similar to type 2 or type 3 Brugada pattern in the electrocardiographic (ECG) performed at a higher position. Cardiac magnetic resonance (CMR), has shown conflicting data regarding existence of structural abnormalities in patients with idiopathic PVCs from the RVOT. Objective: Our aim was to evaluate the prevalence of low voltage areas (LVAs) in the RVOT of patients with PVCS from the outflow tract, and in a control group. Secondly, assess for the presence of a non-invasive ECG marker. Methods: A 56 consecutive patients, 45 with frequent PVCs (>10000/24 h) LBBB, vertical axis, negative in aVL and 11 subjects without PVCs. Arrhythmogenic right ventricular cardiomyopathy was ruled out in all patients. An ECG was performed with V1-V2 at the level of the second intercostal space and the presence of ST-segment elevation with a Type 2 or 3 Brugada pattern (Type 2 BrP) was assessed. Bipolar voltage map of the RVOT was performed in sinus rhythm (0.5-1.5 mV color display). Areas with electrograms <1.5 mV represented the LVA. The area adjacent to the pulmonary valve usually displays voltage between 0.5 and 1.5 mV and is classified as transitional-voltage zone. Presence of LVAs outside this transitional-voltage zone were estimated. We compared two groups with and without ST-segment elevation and tested for the association between ECG pattern and LVAs. Results: None of the patients in the control group had ST-segment elevation or LVAs. In the PVC group, no patient had type 1 Brugada pattern, 29 patients (64%) had type 2 or 3 ST-segment elevation (Type 2 BrP), and 28 (62%) had LVAs outside the transitional-voltage zone. LVAs were more frequent in patients with Type 2 BrP; 93% versus 4%, p < 0.0001. The ECG pattern was associated with the presence of LVAs, OR (95% CI): 202.50 (16.92-2423), p < 0.0001. Conclusion: Low voltage areas were frequently present in the RVOT of patients with idiopathic PVCs. They were absent in controls and can be unmasked by the presence of Type 2 BrP in high right precordial leads.

Template-Assisted Self-Assembly of Conductive Polymer Electrodes for Ionic Electroactive Polymers

Ionic electroactive polymers (ionic EAPs) can greatly aid in biomedical applications where micro-sized actuators are required for delicate procedures. Since these types of actuators generally require platinum or gold metallic electrodes, they tend to be expensive and susceptible to delamination. Previous research has solved this problem by replacing the metallic electrodes with conductive polymers (CP) and forming an interpenetrating polymer network (IPN) between the conductive polymer (CP) and the solid polymer electrolyte (SPE). Since these actuators contain toxic ionic liquids, they are unsuitable for biological applications. In this study, we present a novel and facile method of fabricating a biocompatible and ionic liquid-free actuator that uses semi-IPN to hold the CP and Nafion-based SPE layers together. Surface activated fabrication treatment (SAFT) is applied to the precursor-Nafion membrane in order to convert the sulfonyl fluoride groups on the surface to sulfonate. Through template-assisted self-assembly, the CP electrodes from either polyaniline (PANI) or poly(3,4-ethylenedioxythiophene) (PEDOT) interlock with the surface treated precursor-Nafion membrane so that no delamination can occur. The electrodes growth pattern, interfacial layer's thickness, and shape can be controlled by adjusting the SAFT concentration and duration.

Vertical GaN-on-GaN Schottky Diodes as α-Particle Radiation Sensors

Among the different semiconductors, GaN provides advantages over Si, SiC and GaAs in radiation hardness, resulting in researchers exploring the development of GaN-based radiation sensors to be used in particle physics, astronomic and nuclear science applications. Several reports have demonstrated the usefulness of GaN as an α-particle detector. Work in developing GaN-based radiation sensors are still evolving and GaN sensors have successfully detected α-particles, neutrons, ultraviolet rays, x-rays, electrons and γ-rays. This review elaborates on the design of a good radiation detector along with the state-of-the-art α-particle detectors using GaN. Successful improvement in the growth of GaN drift layers (DL) with 2 order of magnitude lower in charge carrier density (CCD) (7.6 × 1014/cm3) on low threading dislocation density (3.1 × 106/cm2) hydride vapor phase epitaxy (HVPE) grown free-standing GaN substrate, which helped ~3 orders of magnitude lower reverse leakage current (IR) with 3-times increase of reverse breakdown voltages. The highest reverse breakdown voltage of -2400 V was also realized from Schottky barrier diodes (SBDs) on a free-standing GaN substrate with 30 μm DL. The formation of thick depletion width (DW) with low CCD resulted in improving high-energy (5.48 MeV) α-particle detection with the charge collection efficiency (CCE) of 62% even at lower bias voltages (-20 V). The detectors also detected 5.48 MeV α-particle with CCE of 100% from SBDs with 30-μm DL at -750 V.

Low-Voltage Organic Nonvolatile Memory Transistors with Water-Soluble Polymers Containing Thermally Induced Radical Dipoles

A water-soluble acidic polymer, poly(2-acrylamido-2-methyl-1-propanesulfonic acid) (PAMPSA), was applied as a gate-insulating layer for organic field-effect transistors (OFETs). Before depositing the poly(3-hexylthiophene) (P3HT) channel layers, the PAMPSA layers were subjected to thermal treatment at various temperatures from 140 to 230 °C. The OFET performance was greatly enhanced by thermal treatment between 140 and 170 °C, whereas it became very poor at higher temperatures (200-230 °C). In particular, the transfer curves showed pronounced hysteresis phenomena at 170 °C. Various measurements including thermogravimetric analysis and X-ray photoelectron spectroscopy disclosed that the PAMPSA chains underwent thermal degradation from ca. 160 °C and could generate carbon radicals leading to the formation of dipoles with the nitrogen lone pair electrons. The carbon-nitrogen dipoles delivered hysteresis phenomena to the OFETs with the PAMPSA layers treated at 170 °C, which exhibited excellent memory retention characteristics up to 10 000 cycles even at -1 V. Hence, it is expected that the thermally treated PAMPSA layers can be used as one of the viable gate-insulating memory materials for low-voltage transistor-type organic memory devices (TOMDs).

Epidemiology of electrical burns: a 10-year retrospective analysis of 376 cases at a burn centre in South China

OBJECTIVE

To investigate the epidemiological profile and associated outcomes of electrical injuries at a major burn centre in southern China.

METHODS

This retrospective study enrolled consecutive electrical burn patients admitted to the burn centre of the First Affiliated Hospital of Guangxi Medical University between 2008 and 2017. Demographic and clinical data and outcomes were recorded. Mann-Whitney U tests/Pearson's chi-squared tests were used to examine the differences between low-voltage and high-voltage injuries.

RESULTS

There were 217 high-voltage injuries and 159 low-voltage injuries. High-voltage burns were frequently observed between March and August, and low-voltage burns peaked between June and September. Burn patients were mainly men. Most burns occurred in participants aged 21 to 50 years and in industrial workers and electricians at work or householders at home. Only one person with high-voltage burns died (a mortality rate of 0.46%). Amputation rates were 37.33% for high-voltage burns and 22.01% for low-voltage burns. High-voltage injuries were associated with more extensive burns, longer hospital stays, and more complications and amputations.

CONCLUSIONS

More attention should be paid to prevention of electrical burns in male adults. Particular focus is needed on industrial workers, incidents in the spring and summer, and high-voltage injuries.

Low Voltage High-Energy α-Particle Detectors by GaN-on-GaN Schottky Diodes with Record-High Charge Collection Efficiency

A low voltage (−20 V) operating high-energy (5.48 MeV) α-particle detector with a high charge collection efficiency (CCE) of approximately 65% was observed from the compensated (7.7 × 10¹⁴ /cm³) metalorganic vapor phase epitaxy (MOVPE) grown 15 µm thick drift layer gallium nitride (GaN) Schottky diodes on free-standing n+-GaN substrate. The observed CCE was 30% higher than the bulk GaN (400 µm)-based Schottky barrier diodes (SBD) at −20 V. This is the first report of α–particle detection at 5.48 MeV with a high CCE at −20 V operation. In addition, the detectors also exhibited a three-times smaller variation in CCE (0.12 %/V) with a change in bias conditions from −120 V to −20 V. The dramatic reduction in CCE variation with voltage and improved CCE was a result of the reduced charge carrier density (CCD) due to the compensation by Mg in the grown drift layer (DL), which resulted in the increased depletion width (DW) of the fabricated GaN SBDs. The SBDs also reached a CCE of approximately 96.7% at −300 V.

Exploring the Parameter Space of Point Spread Function Determination for the Scanning Electron Microscope-Part II: Effect on Image Restoration Quality

Point spread function (PSF) deconvolution is an attractive software-based technique for resolution improvement in the scanning electron microscope (SEM) because it can restore information which has been blurred by challenging operating conditions. In Part 1, we studied a modern PSF determination method for SEM and explored how various parameters affected the method's ability to accurately estimate the PSF. In Part 2, we extend this exploration to PSF deconvolution for image restoration. The parameters include reference particle size, PSF smoothing (K), background correction, and restoration denoising (λ). Image quality was assessed by visual inspection and Fourier analysis. Overall, PSF deconvolution improved image quality. Low λ enhanced image sharpness at the cost of noise, while high λ created smoother restorations with less detail. λ should be chosen to balance feature preservation and denoising based on the application. Reference particle size within ±0.9 nm and K within a reasonable range had little effect on restoration quality. Restorations using background-corrected PSFs had superior quality compared with using no background correction, but if the correction was too high, the PSF was cut off causing blurrier restorations. Future efforts to automatically determine parameters would remove user guesswork, improve this method's consistency, and maximize interpretability of outputs.

0.2 V Electrolysis Voltage-Driven Alkaline Hydrogen Production with Nitrogen-Doped Carbon Nanobowl-Supported Ultrafine Rh Nanoparticles of 1.4 nm

The development of highly effective and low-cost electrocatalysts for energy-saving hydrogen production via water splitting is still a great challenge. Herein, porous nitrogen-doped carbon nanobowls (N-CBs) have been designed and used for the controlled growth of ultrafine rhodium (Rh) nanoparticles. With the aid of interfacial bonding of Rh and N, ultrafine Rh nanoparticles with an average size of 1.4 nm have been successfully immobilized on the N-CBs. This Rh/N-CB electrocatalyst shows superior activity and high stability for the hydrogen evolution reaction (HER) and the hydrazine oxidation reaction (HzOR). More importantly, the Rh/N-CBs exhibit high activity for hydrogen production from water electrolysis, marking with a cell voltage of 0.2 V to achieve a current density of 20 mA cm^-2 when they serve as cathodic electrocatalysts for the HER and anodic electrocatalysts for the HzOR in 1 M KOH with 0.5 M hydrazine. The density functional theory calculations demonstrate that a near-zero hydrogen adsorption free energy produced by the chemical bonding of Rh with the pyrrole-N doped in N-CBs is responsible for the excellent HER activity of Rh/N-CBs electrocatalysts.

Low-Voltage Surface Electrocoalescence Enabled by High-K Dielectrics and Surfactant Bilayers for Oil-Water Separation

Processes for separating oil-water mixtures are critical to operations in energy and water. However, existing separation methods pose efficiency limitations as well as environmental and safety challenges. Here, we present a low-voltage surface electrocoalescence approach that triggers coalescence of surfactant-stabilized emulsions by combining high-K dielectrics with surfactant bilayers. In this system, the high-K dielectric reduces the electrocoalescence voltage, while the surfactant bilayer functions as a self-healing, high capacitance film that prevents pinning of droplets on the dielectric surface. This high capacitance system maximizes the electric field between neighboring droplets, exerting high electrostatic pressure that overcomes the disjoining pressure between droplets, thereby enabling rapid electrocoalescence. We demonstrate electrocoalescence of surfactant-stabilized microscale droplets of saline water in oil using single volts. We expect our results may find application in the energy sector, wastewater treatment, and purification industries.

High-Performance Low-Voltage Flexible Photodetector Arrays Based on All-Solid-State Organic Electrochemical Transistors for Photosensing and Imaging

The identifying characteristic of an organic electrochemical transistor (OECT) is the coupling between ionic and electronic charges within the entire volume of the channel. In this work, by taking advantage of the volumetric nature of the OECTs' response, a novel flexible photodetector is reported for the first time based on all-solid-state OECT with an excellent responsivity of up to 6.7 × 10⁶ A/W, detectivity as high as 3.6 × 10¹³ Jones, and a fast response of ∼0.13 s in the visible range, which are superior to those of the majority of the reported organic phototransistors (OPTs) based on field-effect transistors (FETs) and even better than those of FET-based phototransistors with two-dimensional (MoS₂ and graphene) and perovskite materials. The high performance of the devices was ascribed to the combination of the higher carrier mobility of poly(3,4-ethylenedioxythiophene) doped with poly(styrene sulfonate) (PEDOT:PSS) as a channel and the volumetric nature of the OECTs' response, and the charge density of the volumetric channel was efficiently modulated by incident light compared to FETs. Moreover, OECT-based OPTs with quantum dots (CdSe/ZnS) as a light sensitizer were characterized under ultraviolet light, and they exhibited excellent photosensitivity, which further verified the superiority of OECT for phototransistors. Furthermore, a flexible image sensor was fabricated for the first time by integrating flexible OECTs-OPTs into a 10 × 10 array, which can clearly identify the target image under a bending state, indicating the great potential of OECTs-OPTs in the application of low-power, ultrasensitive flexible photodetectors and imaging technology.

Bipolar Voltage Mapping for the Evaluation of Atrial Substrate: Can We Overcome the Challenge of Directionality?

The relationship between atrial fibrosis and atrial fibrillation (AF) has been proven. Patient specific substrate ablation targeting fibrotic tissue estimated by bipolar voltage mapping has emerged as an alternative strategy for additional substrate modification beyond pulmonary vein isolation. The primary mechanism of a low-voltage electrogram has been suggested to be atrial fibrosis, however, no direct correlation between histological fibrosis and low-voltage zone has been confirmed. Furthermore, the definition of low-voltage zone is still controversial, and bipolar voltage amplitudes depend on multiple variables including electrodes orientation relative to direction of wavefront, electrode length, interelectrode spacing, and tissue contact. The aim of this article is to review the role and limitation of voltage mapping, and to share our initial experience of a newly released grid-pattern designed mapping catheter to make the voltage mapping more reliable to guide patient specific AF ablation.

Solution-Processed Organic Field-Effect Transistors with High Performance and Stability on Paper Substrates

High-performance operationally stable organic field-effect transistors were successfully fabricated on a PowerCoat HD 230 paper substrate with a TIPS-pentacene:polystyrene blend as the active layer and poly(4-vinylphenol)/HfO₂ as the hybrid gate dielectric. The fabricated devices exhibited excellent p-channel characteristics with a maximum and av field effect mobility of 0.44 and 0.22(±0.11) cm² V^-1 s^-1, respectively, av threshold voltage of 0.021(±0.63) V, and current on-off ratio of ∼10⁵ while operating at -10 V. These devices exhibited remarkable stability under effects of gate bias stress and large number of repeated transfer scans with negligible performance spread. In addition, these devices displayed very stable electrical characteristics after long exposure periods to humidity and an excellent shelf life of more than 6 months in ambient environment. Thermal stress at high temperatures however deteriorates the device characteristics because of the generation and propagation of cracks in the active semiconductor crystals. Furthermore, novel paper-based phototransistors have been demonstrated with these devices.

Laterally Movable Triple Electrodes Actuator toward Low Voltage and Fast Response RF-MEMS Switches

A novel actuator toward a low voltage actuation and fast response in RF-MEMS (radio frequency micro-electro-mechanical systems) switches is reported in this paper. The switch is comprised of laterally movable triple electrodes, which are bistable by electrostatic forces applied for not only the on-state, but also the off-state. The bistable triple electrodes enable the implementation of capacitive series and shunt type switches on a single switch, which leads to high isolation in spite of the small gap between the electrodes on the series switch. These features of the actuator are effective for a low voltage and fast response actuation in both the on- and off-state. The structure was designed in RF from a mechanical point of view. The laterally movable electrodes were achieved using a simple, low-cost two-mask process with 2.0 µm thick sputtered aluminum. The characteristics of switching response time and actuation voltage were 5.0 µs and 9.0 V, respectively.

Empirical and Theoretical Modeling of Low-Frequency Noise Behavior of Ultrathin Silicon-on-Insulator MOSFETs Aiming at Low-Voltage and Low-Energy Regime

This paper theoretically revisits the low-frequency noise behavior of the inversion-channel silicon-on-insulator metal-oxide-semiconductor field-effect transistor (SOI MOSFET) and the buried-channel SOI MOSFET because the quality of both Si/SiO₂ interfaces (top and bottom) should modulate the low-frequency fluctuation characteristics of both devices. It also addresses the low-frequency noise behavior of sub-100-nm channel SOI MOSFETs. We deepen the discussion of the low-frequency noise behavior in the subthreshold bias range in order to elucidate the device’s potential for future low-voltage and low-power applications. As expected, analyses suggest that the weak inversion channel near the top surface of the SOI MOSFET is strongly influenced by interface traps near the top surface of the SOI layer because the traps are not well shielded by low-density surface inversion carriers in the subthreshold bias range. Unexpectedly, we find that the buried channel is primarily influenced by interface traps near the top surface of the SOI layer, not by traps near the bottom surface of the SOI layer. This is not due to the simplified capacitance coupling effect. These interesting characteristics of current fluctuation spectral intensity are explained well by the theoretical models proposed here.

Electron Beam-Induced Carbon Erosion and the Impact on Electron Probe Microanalysis

Electron beam-induced carbon contamination is a balance between simultaneous deposition and erosion processes. Net erosion rates for a 25 nA 3 kV beam can reduce a 5 nm C coating by 20% in 60 s. Measurements were made on C-coated Bi substrates, with coating thicknesses of 5-20 nm, over a range of analysis conditions. Erosion showed a step-like increase with increasing electron flux density. Both the erosion rate and its rate of change increase with decreasing accelerating voltage. As the flux density decreases the rate of change increases more rapidly with decreasing voltage. Time-dependent intensity (TDI) measurements can be used to correct for errors, in both coating and substrate quantifications, resulting from carbon erosion. Uncorrected analyses showed increasing errors in coating thickness with decreasing accelerating voltage. Although the erosion rate was found to be independent of coating thickness this produces an increasing absolute error with decreasing starting thickness, ranging from 1.5% for a 20 nm C coating on Bi at 15 kV to 14% for a 5 nm coating at 3 kV. Errors in Bi Mα measurement are &lt;1% at 5 kV or above but increase rapidly below this, both with decreasing voltage and increasing coating thickness to 20% for a 20 nm coated sample at 3 kV.

Validating Left Atrial Low Voltage Areas During Atrial Fibrillation and Atrial Flutter Using Multielectrode Automated Electroanatomic Mapping

OBJECTIVES

This study aimed: 1) to determine the voltage correlation between sinus rhythm (SR) and atrial fibrillation (AF)/atrial flutter (AFL) using multielectrode fast automated mapping; 2) to identify a bipolar voltage cutoff for scar and/or low voltage areas (LVAs); and 3) to examine the reproducibility of voltage mapping in AF.

BACKGROUND

It is unclear if bipolar voltage cutoffs should be adjusted depending on the rhythm and/or area being mapped.

METHODS

High-density mapping was performed first in SR and afterward in induced AF/AFL. In some patients, 2 maps were performed during AF. Maps were combined to create a new one. Points of <1 mm difference were analyzed. Correlation was explored with scatterplots and agreement analysis was assessed with Bland-Altman plots. The generalized additive model was also applied.

RESULTS

A total of 2,002 paired-points were obtained. A cutoff of 0.35 mV in AFL predicted a sinus voltage of 0.5 mV (95% confidence interval [CI]: 0.12 to 2.02) and of 0.24 mV in AF (95% CI: 0.11 to 2.18; specificity [SP]: 0.94 and 0.96; sensitivity [SE]: 0.85 and 0.75, respectively). When generalized additive models were used, a cutoff of 0.38 mV was used for AFL for predicting a minimum value of 0.5 mV in SR (95% CI: 0.5 to 1.6; SP: 0.94, SE: 0.88) and of 0.31 mV for AF (95% CI: 0.5 to 1.2; SP: 0.95, SE: 0.82). With regard to AF maps, there was no change in the classification of any left atrial region other than the roof.

CONCLUSIONS

It is possible to establish new cutoffs for AFL and/or AF with acceptable validity in predicting a sinus voltage of <0.5 mV. Multielectrode fast automated mapping in AFL and/or AF seems to be reliable and reproducible when classifying LVAs. These observations have clinical implications for left atrial voltage distribution and in procedures in which scar distribution is used to guide pulmonary vein isolation and/or re-isolation.

Flexible, Low-Voltage, and n-Type Infrared Organic Phototransistors with Enhanced Photosensitivity via Interface Trapping Effect

Flexible and low-voltage near-infrared organic phototransistors (NIR OPTs) were prepared with a low-band gap donor-acceptor conjugated polymer as the semiconductor layer and n-octadecyl phosphonic acid modified anodic alumina (AlO _x/ODPA) as the insulating layer. The phototransistors exhibit the typical n-type transistor characteristics at a voltage below 5 V. The photosensitivity of phototransistors can be enhanced by regulating the packing densities of the ODPA self-assembled monolayers and forming different trap states. The enhanced OPTs exhibit good photosensitivity to 808-980 nm NIR with the photocurrent/dark current ratio and photoresponsivity as high as 5 × 10³ and 20 mA W^-1, respectively, benefiting from the charge-trapping effect at the AlO _x/ODPA interface. The OPTs also present a fast optical switching speed of 20/30 ms and an excellent mechanical flexibility. The outstanding performance of the NIR OPTs indicates that the development of wearable electronics is, indeed, possible.

Room-Temperature Solution-Synthesized p-Type Copper(I) Iodide Semiconductors for Transparent Thin-Film Transistors and Complementary Electronics

Here, room-temperature solution-processed inorganic p-type copper iodide (CuI) thin-film transistors (TFTs) are reported for the first time. The spin-coated 5 nm thick CuI film has average hole mobility (µFE ) of 0.44 cm2 V-1 s-1 and on/off current ratio of 5 × 102 . Furthermore, µFE increases to 1.93 cm2 V-1 s-1 and operating voltage significantly reduces from 60 to 5 V by using a high permittivity ZrO2 dielectric layer replacing traditional SiO2 . Transparent complementary inverters composed of p-type CuI and n-type indium gallium zinc oxide TFTs are demonstrated with clear inverting characteristics and voltage gain over 4. These outcomes provide effective approaches for solution-processed inorganic p-type semiconductor inks and related electronics.

Quantification of Olivine Using Fe Lα in Electron Probe Microanalysis (EPMA)

Quantification of first series transition metal Lα X-rays is hampered by absorption and in some cases transition probabilities (fluorescence yields) varying with chemical bonding. Compound mass absorption coefficients for Fe Lα were measured in the olivine solid solution series [Forsterite (Mg2SiO4) to Fayalite (Fe2SiO4)] and the mass absorption coefficients for Fe Lα absorbed by Fe were calculated. The mass absorption coefficients vary systematically between Fo83 and Fo0. Using the measured mass absorption coefficients for both standard and unknown and by correcting for a systematic discrepancy, consistent with varying partial fluorescence yields, a good agreement between calculated k-ratios and measured k-ratios is achieved. The systematic variations allow quantification of unknown k-ratios. The described method of quantification requires modification of matrix correction routines to allow standards and unknowns to have different mass absorption coefficients, and to incorporate solid solution mass absorption coefficients and partial fluorescence yield corrections derived from regression of experimental data.

Versatile Indolocarbazole-Isomer Derivatives as Highly Emissive Emitters and Ideal Hosts for Thermally Activated Delayed Fluorescent OLEDs with Alleviated Efficiency Roll-Off

Maintaining high efficiency at high brightness levels is an exigent challenge for real-world applications of thermally activated delayed fluorescent organic light-emitting diodes (TADF-OLEDs). Here, versatile indolocarbazole-isomer derivatives are developed as highly emissive emitters and ideal hosts for TADF-OLEDs to alleviate efficiency roll-off. It is observed that photophysical and electronic properties of these compounds can be well modulated by varying the indolocarbazole isomers. A photoluminescence quantum yield (η_PL ) approaching unity and a maximum external quantum efficiency (EQE_max ) of 25.1% are obtained for the emitter with indolo[3,2-a]carbazolyl subunit. Remarkably, record-high EQE/power efficiency of 26.2%/69.7 lm W^-1 at the brightness level of 5000 cd m^-2 with a voltage of only 3.74 V are also obtained using the same isomer as the host in a green TADF-OLED. It is evident that TADF hosts with high η_PL values, fast reverse intersystem crossing processes, and balanced charge transport properties may open the path toward roll-off-free TADF-OLEDs.

Coronary sinus signal amplitude predicts left atrial scarring

BACKGROUND

Left atrial scarring is recognised as a critical component in the maintenance of atrial fibrillation and is associated with the failure of interventional treatment. Diminished bipolar voltage (LV) has been proposed as a useful tool for left atrial scar quantification. We hypothesised that, due to its anatomic location, signals on the coronary sinus catheter might be used to predict the amount of left atrial low voltage.

METHODS AND RESULTS

A total of 124 patients (42% women, average age 66 ± 9 years) were included. Forty-one with paroxysmal and 83 with persistent atrial fibrillation. Left atrial low-voltage (<0.5 mV, measured during sinus rhythm) area size and distribution varied considerably among the included patients (mean: 34.9%; maximum: 94.6%; minimum: 0.4%). Spearman correlation revealed a strong negative correlation between bipolar voltage of the signals on the coronary sinus catheter and the amount of left atrial scarring (R = -0.778, p < .0001). The optimal CS voltage cut off for prediction of left atrial low-voltage size of ≥50% was 1.9 mV with an area-under-the receiver-operating-characteristic (ROC) curve of 0.982, a sensitivity of 97% and a specificity of 98%.

CONCLUSIONS

There is a strong negative correlation between the size of left atrial low-voltage areas (LVA) and coronary sinus signal amplitude. With increasing left atrial LVA size, CS signal amplitudes decrease, and vice versa. On the basis of these findings, average CS signal amplitudes of ≤1.9 mV can be used as a predictor for a left atrial low-voltage size of ≥50%.

Ultrathin Layered SnSe Nanoplates for Low Voltage, High-Rate, and Long-Life Alkali-Ion Batteries

2D electrode materials with layered structures have shown huge potential in the fields of lithium- and sodium-ion batteries. However, their poor conductivity limits the rate performance and cycle stability of batteries. Herein a new colloid chemistry strategy is reported for making 2D ultrathin layered SnSe nanoplates (SnSe NPs) for achieving more efficient alkali-ion batteries. Due to the effect of weak Van der Waals forces, each semiconductive SnSe nanoplate stacks on top of each other, which can facilitate the ion transfer and accommodate volume expansion during the charge and discharge process. This unique structure as well as the narrow-bandgap semiconductor property of SnSe simultaneously meets the requirements of achieving fast ionic and electronic conductivities for alkali-ion batteries. They exhibit high capacity of 463.6 mAh g^-1 at 0.05 A g^-1 for Na-ion batteries and 787.9 mAh g^-1 at 0.2 A g^-1 for Li-ion batteries over 300 cycles, and also high stability for alkali-ion batteries.

Right Ventricle Outflow Obstruction in Biventricular Hypertrophic Cardiomyopathy in Amyloidosis

Light-chain (AL) amyloidosis is the most common type of amyloidosis; cardiac involvement is rare but has a poor prognosis. Biventricular hypertrophic cardiomyopathy is an exceptional finding in amyloidosis and its association with obstructive right ventricular gradient is even rarer. We report the case of a male patient with biventricular hypertrophy suggesting amyloidosis, with an obstructive gradient in the right ventricle.