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The paper presents the results of experimental studies of the operation of hybrid X-pinches on a modified high-current KING generator. The KING generator is a portable pulse current generator based on four low-inductive pulse capacitors. The output assembly of the generator was modified for greater diagnostic access to the load, which led to an increase in the inductance of the entire circuit and an increase in the duration of the current rise. A series of experiments with hybrid X-pinches with Al, Cu, and Mo wires with a diameter of 25 μm was carried out on the modified KING generator (200–260 kA, 220–280 ns, 45 kV). In experiments, it was shown that such a modification of the generator led to the stable formation of bright soft x-ray sources in X-pinches, suitable for use in point-projection radiography with a spatial resolution of about 10–15 μm. [ABSTRACT FROM AUTHOR]

We present results exploring various methods of aluminum flyer acceleration. One method uses the shock wave generated by underwater electrical explosions of thin foils supplied by a pulse generator with stored energy of ∼4.7 kJ. Utilizing the shock created by an exploding foil, a maximal free flyer velocity of ∼2000 m/s is obtained. This acceleration method is compared to results exploiting only magnetic pushing to accelerate flyers using a common strip-line configuration, resulting in much lower velocities of ∼300 m/s. We also present a modified strip-line configuration, for which a significant increase in the flyer velocity to ∼1200 m/s is measured. Finally, a hybrid strip configuration, incorporating both the effects of magnetic pushing and acceleration by exploding foil and its subsequent shock wave, results in ∼1400 m/s flyer velocity. These experimental results are analyzed by numerical simulations and analytical modeling of the conservation equations of mass and momentum. [ABSTRACT FROM AUTHOR]

High-power pulse generators are widely used in civil and military fields. The main switch directly determines the output characteristics of the high-power pulse generators, such as the voltage front time (t f). Pseudospark switches (PSS) show a promising future for middle voltage, high repetitive frequency pulse power applications. However, how to further improve the breakdown behavior without reducing its advantages is a challenging task. In this paper, the influence of operating parameters (anode voltage U A and gas pressure p) and structural parameter (number of cathode holes) on the breakdown behavior are investigated, the related mechanism are explained, and specific improvement schemes are proposed. It is found that the t f of the single channel PSS (SCPSS) decreased significantly with increasing p, but hardly varied with U A under moderate p. However, it is not a sound solution to increase the p excessively to reduce t f. Besides, increasing the number of cathode holes can obtain a shorter t f at low pressures (which implies superior repetition frequency performance). However, at 25 Pa, the jitter (which is defined as the standard deviation of t f in multiple tests) of the 2-channel PSS is larger than that of the SCPSS. And the jitter of the 4-channel and 8-channel PSS is also greater than 6 ns and 2 ns, respectively. Through experimental and simulation analyses, it can be explained as the stepwise penetration of the virtual anode and the non-simultaneous ignition of the channels. A scheme to increase the trigger energy (ϵ) has been adopted to improve the simultaneous ignition probability, while shortening t f and reducing jitter. After optimization, the good ignition probability of the 4-channel PSS has been improved to 82% and the jitter has been reduced to less than 1 ns at 25 Pa and 14.7 mJ. [ABSTRACT FROM AUTHOR]

Memristors (MRs) have been used in integrated circuit design due to their nanoscale size and low power consumption. In this study, a flux-controlled binary MR emulator is designed by using off-the-shelf circuit components. Then, two MR-based multi-vibrators are constructed and applied to pulse train (PT) controlled Buck converters. Compared with traditional PT controlled Buck converters requiring two pulse train generators, only one single memristive pulse generator with controllable duty cycle is used to regulate the output voltage. To suppress the low-frequency oscillations of the PT-controlled Buck converter in continuous conduction mode (CCM), an inductor current based PT (IC-PT) control method is devised with the proposed MR-based pulse generator. Simulation and experimental results both show that the IC-PT-controlled Buck converter with the MR-based pulse generator can achieve fast transient response and minimum low-frequency voltage oscillations in the CCM. [ABSTRACT FROM AUTHOR]

Traditional high-voltage pulse generators, like Marx generators often face challenges related to efficiency and complexity. In this paper, a solid-state multi-module high-voltage pulse generator that integrates capacitor-diode voltage multipliers (CDVM) with DC-DC boost converters and closed-loop voltage control is proposed to overcome these challenges. The system achieves high output voltage by coupling the pulsed output voltages of individual low-voltage DC sources in series across each module. The proposed design was modeled using MATLAB, and experimental testing was conducted on a single stage. Comparative analyses between timedomain parameters, proportional-integral (PI), and fractional order proportional integral derivative (FOPID) controllers were performed. Both MATLAB simulations and experimental validations demonstrate the effectiveness of this approach. The rise time, peak time, settling time, and steady-state error are all improved using an FOPID controller, decreasing from 0.32 to 0.31 seconds, 0.42 to 0.35 seconds, and 3.15 to 2.20 seconds, respectively. These findings indicate that a closed-loop FOPID controller enhances time-domain performance parameters more effectively than a PI controller for a two-stage DC-DC voltage multiplier. [ABSTRACT FROM AUTHOR]

Objective Methods Results Conclusions Occipital Nerve Stimulation (ONS) is increasingly used to treat a range of chronic, refractory headache conditions, most notably chronic cluster headache (CCH).Despite this, there is still no consensus on the optimal implantation technique. Clinical reports and reviews in the field have reported remarkably high complication rates of which several can be directly related to the surgical approach.We here describe a comprehensive and detailed surgical approach used at Aarhus University Hospital, Denmark, aiming to improve paresthesia coverage and minimize complications.The implantation procedure described here is performed with a sleep‐awake anesthetic regimen in a lateral position using anatomical landmarks and perioperative testing based on patient feedback. A single lead is subcutaneously implanted from behind the ear and across the back of the head, and the implantable pulse generator (IPG) is placed below the right clavicle.From March 2018 to June 2024, 45 CCH patients were implanted using this approach and followed up for a total of 86.3 patient years. A total of 22 adverse events (AEs) occurred in 17 patients, with nine AEs requiring revision surgery. Notably, no instances of lead migration, lead breakage, or muscle/neck stiffness were observed. Temporary occipital dysesthesia was the most frequent non‐surgical AE, resolving spontaneously within weeks. The rate of serious adverse events (SAEs) was one per 9.6 patient years. Six patients had the ONS system explanted due to lack of efficacy.The surgical approach described here in detail offers several advantages, with a favorable complication profile, satisfactory paresthesia coverage, and good perioperative patient comfort. Advances in the surgical technique are vital to both patients and healthcare providers, and we believe this approach is a valuable contribution toward improved patient outcomes and procedural efficiency. [ABSTRACT FROM AUTHOR]

Controlling electron density in two-dimensional semiconductors is crucial for both comprehensive understanding of fundamental material properties and their technological applications. However, conventional electrostatic doping methods exhibit limitations, particularly in addressing electric field-induced drift and subsequent diffusion of electrons, which restrict nanoscale doping. Here, we present a tip-induced nanospectroscopic electric pulse modulator to dynamically control nanoscale electron density, thereby facilitating precise measurement of nano-optoelectronic behaviors within a MoS2 monolayer. The tip-induced electric pulse enables nanoscale modulation of electron distribution as a function of electric pulse width. We simultaneously investigate spatially altering photoluminescence quantum yield at the nanoscale region. We model the extent of electron depletion region, confirming a minimum doping region with a radius of ~265 nanometers for a 30-nanosecond pulse width. Our approach paves the way for engineering local electron density and in situ nano-optical characterization in two-dimensional materials, enabling an in-depth understanding of doping-dependent nano-optoelectronic phenomena. [ABSTRACT FROM AUTHOR]

Background Cardiac implantable electronic devices (CIEDs) are prone to electromagnetic interference. Common sources include household electronics and industrial machinery. However, medical equipment can also trigger interferences and cause CIED malfunction. Case summary We report on a 79-year-old male with sudden onset of presyncope. He has a long history of device therapy, including an active VVI leadless pacemaker and an abandoned abdominal pacemaker with epicardial leads. Automatic reactivation of the abandoned pacemaker due to reaching end-of-life mode led to interaction with the active pacemaker, inhibiting it in its function. Due to elevated capture threshold and insufficient output, pacing by the reactivated pacemaker was accompanied by intermittent loss of myocardial capture and patient symptoms. By changing the mode to VOO and increasing the pacing rate of the active pacemaker, the interaction was prevented as an intermittent solution. The final therapy consisted of explanting the pulse generator of the abdominal pacemaker. Discussion We present a patient with a deactivated abandoned cardiac pacemaker, which self-activated after reaching end-of-life mode and triggered an interaction with his active pacemaker. This case emphasizes the importance of explanting old devices to avoid potential interaction. [ABSTRACT FROM AUTHOR]

Importance: Many women report inadequate symptom control after sacral neuromodulation (SNM), despite 50% reduction in urgency incontinence episodes (UUIE) after test stimulation. Objective: To determine the ideal percent UUIE reduction after test stimulation that predicts 24‐month success. Study Design: Using data from a multicenter SNM trial, we constructed receiver operating characteristic curves to identify an ideal threshold of percent UUIE reduction after test stimulation. We defined 24‐month success as Patient Global Impression of Improvement of "very much better" to "better." We compared predictive accuracy of two models predicting success: (1) percent UUIE reduction alone and (2) with baseline characteristics. Results: Of 149 women (median [IQR] baseline daily UUIE 4.7 [3.7, 6.0]), the ideal threshold for 24‐month success was 72% (95% confidence interval 64,76%) UUIE reduction with accuracy 0.54 (0.42, 0.66), sensitivity 0.71 (0.56, 0.86) and specificity 0.27 (0.05, 0.55). The accuracy of the 50% reduction threshold was 0.60 (0.49, 0.71), sensitivity 0.95 (0.88, 1.0) and specificity 0.04 (0.0, 0.12). Percent reduction in UUIE was not better than chance in predicting 24‐month success (concordance index [c‐index] 0.47 [0.46, 0.62]); adding age, body mass index, diabetes mellitus and visual or hearing impairment the c‐index was 0.68 (0.61, 0.78). Conclusions: Among women who received an internal pulse generator (IPG) due to ≥50% UUIE reduction after test stimulation, we found no ideal threshold that better predicted 24‐month success. Percent reduction in UUIE after test stimulation poorly predicts 24‐month success with or without clinical factors. Given this, re‐evaluating how we determine who should receive an IPG is needed. [ABSTRACT FROM AUTHOR]

High-voltage discharge applications have seen a widespread adoption of solid-state Marx generators (SSMGs) in recent years. In this paper, we propose a new hybrid solid-state Marx generator (HSSMG) with a single inductor. Through the application of a three-phase Fibonacci scheme, the HSSMG is capable of achieving a substantial increase in voltage output. Furthermore, the proposed HSSMG is able to generate high voltage efficiently with fewer components. The integration of the Fibonacci and boost modules is a crucial idea in the proposed technique, where the boost module increases the output voltage of the Fibonacci module to achieve higher output voltage. Regarding the proposed two-stage HSSMG, the theoretical feasibility of the proposed topology is confirmed by theoretical analysis and Simulation Program with Integrated Circuit Emphasis (SPICE) simulations. As a result of comparative analysis, it was found that the number of circuit components of the proposed two-stage HSSMG is approximately half that of the traditional SSMG. Moreover, the newly suggested two-stage HSSMG accomplishes more than 86% power efficiency at 5 W. [ABSTRACT FROM AUTHOR]

Neutron production driven by intense lasers utilizing inverse kinematic reactions is explored self-consistently by a combination of particle-in-cell simulations for laser-driven ion acceleration and Monte Carlo nuclear reaction simulations for neutron production. It is proposed that laser-driven light-sail acceleration from ultrathin lithium foils can provide an energetic lithium-ion beam as the projectile bombarding a light hydrocarbon target with sufficiently high flux for the inverse p ( L i 7 , n) reaction to be efficiently achieved. Three-dimensional self-consistent simulations show that a forward-directed pulsed neutron source with ultrashort pulse duration 3 ns, small divergence angle 26°, and extremely high peak flux 3 × 1014n/(cm2⋅s) can be produced by petawatt lasers at intensities of 1021 W/cm2. These results indicate that a laser-driven neutron source based on inverse kinematics has promise as a novel compact pulsed neutron generator for practical applications, since the it can operate in a safe and repetitive way with almost no undesirable radiation. [ABSTRACT FROM AUTHOR]

Background: The safety of new‐generation mobile phones using 5G networks in patients with modern‐generation pacemakers has not been studied. Objectives: This study aimed to compare the risk of electromagnetic interference (EMI) generated by a new‐generation mobile phone with 5G networks when positioned at the pacemaker pocket or the contralateral ear and assess the incidence of EMI with telemetry interrogation in patients with permanent pacemakers. Methods: We enrolled 489 patients with pacemakers from three different manufacturers. The pacemaker mode was programmed for overdrive pacing and sensing mode if an intrinsic rhythm was present. A smartphone (Samsung S21 + 5G) was placed directly over the pulse generator and right ear. The phone was tested under standby mode, 5G internet connection, and incoming and outgoing calls for each location. Real‐time electrocardiography (ECG) monitoring and patient symptoms were recorded to determine the occurrence of EMI. The possibility of EMI with interrogation telemetry was also investigated. Results: A total of 4824 tests were performed on 489 patients. Most pacemakers were dual‐chamber (82%) or magnetic resonance imaging (MRI)‐compatible systems (83%). EMI was not detected with both mobile phone positions. Interference with telemetry was demonstrated in 11.5% of patients. Almost all incidences of interference (98.2%) occurred during incoming calls. Single‐chamber pacemakers, non‐MRI‐compatible systems, older pulse generators, older leads, and unipolar settings were significantly related to a higher incidence of interference with interrogation telemetry. Conclusions: The risk of EMI between modern smartphones with 5G networks and pacemakers is low. Nevertheless, interference with the interrogation telemetry may still occur. [ABSTRACT FROM AUTHOR]

Introduction Case Report Conclusion This case report presents an instance of an S‐Series™ slim paddle lead fracturing during extraction, highlighting potential risks associated with the removal of this lead.A 47‐year‐old male with complex regional pain syndrome type 2, unresponsive to pharmacotherapy, had undergone the implantation of two spinal cord stimulator (SCS) leads, an Octrode™ cylindrical and an S‐series™ slim paddle, using the Epiducer™ system (St Jude Medical) 9 years earlier, with a subsequent intrathecal baclofen pump installed 1 year after SCS. Initially, these interventions stabilized the patient's pain symptoms. However, the diminishing effectiveness of SCS, coupled with a decrease in battery life and increased opioid consumption, necessitated recent surgical procedures. These included the removal and replacement of the implantable pulse generator (IPG) and leads to improve pain management and ensure MRI compatibility. During the removal of the S‐series™ slim paddle type lead, complications arose, leading to the retention of an electrode fragment, which necessitated abandoning the replacement of both the IPG and lead. Post‐surgical assessments revealed no new neurological impairments, and imaging studies confirmed the stable position of the retained fragment. The patient was discharged with a continued comprehensive pain management plan.This case highlights the challenges and risks of percutaneous removal of slim paddle type leads, emphasizing the need for careful procedural planning and consideration of surgical options to avoid complications. Further research is needed to evaluate the long‐term durability and removal risks of various SCS lead types. [ABSTRACT FROM AUTHOR]

Background Methods Results Conclusions Spinal Cord Stimulation (SCS) is an established therapy for chronic pain, employing screening trials to identify suitable candidates before implantation. However, complications arising from both technique and medical factors present challenges to this practice. This study introduces the Dural Substitute Confetti technique, which addresses technique‐related complications during SCS implantation by preventing scar‐induced lead migration or breakage and reducing operating times.We conducted a retrospective analysis on 174 patients treated with SCS trials from 2017 to 2022 at our institution. Of these, 85.1% proceeded to permanent implantation. During trial surgery, synthetic dural substitutes (DS) were used to protect leads, which remained connected to an external pulse generator (EPG) for 20–28 days (mean 21.4 days). Utilizing the DS Confetti technique, leads were easily dissected from the DS during the second surgery and connected to an internal pulse generator (IPG). We compared complications and surgical times before and after the introduction of this technique in 2017.Following the complete SCS trial, patients experienced over 50% pain relief, with an implant‐to‐trial ratio of 85.1% and a mean follow‐up of 52 months. No technique‐related complications occurred during the trial period post‐2017, while the pre‐2017 group had a 3.9% lead migration rate due to scarring, necessitating re‐implantation. The average surgery duration decreased from 54 min pre‐2017 to 32 min post‐2017. Medical‐related complications included infections (2.1%) and wound dehiscence (1.3%).The DS Confetti technique prevents scar adhesion formation during screening trials, thereby facilitating and expediting the definitive SCS implantation. Additionally, it may also reduce the risk of lead migration and iatrogenic damage, potentially lowering technique‐related complications. [ABSTRACT FROM AUTHOR]

AbstractTraditional electrical discharge machining (EDM) electrodes have several limitations such as long machining time, low material removal rate MRR, hazard emissions and high energy consumption. To overcome these limitations, new electrodes (plane and frame U-shaped) were manufactured considering the electrode manufacturing classifications, such as electrode flushing mechanism, electrode cross-sectional area and electrode bottom machining area. Experiments were performed on a die-sinking EDM machine using copper electrodes and aluminum alloy workpieces. The results were compared with those obtained using the conventional electrode. The newly manufactured electrodes significantly improved the EDM process performance, reducing the machining time by more than 50%, which implies a higher MRR. The reduced machining time also led to lower costs, emissions and energy consumption for efficient EDM processes. Additionally, surface roughness measurements were performed to compare the surface quality of the machined areas using different pulse-code generator systems and electrodes. The results showed an improvement in the machined surface quality when using the new electrodes in comparison with the conventional electrode when using a roughing pulse code generator system. [ABSTRACT FROM AUTHOR]

A methodology for the design calculation of a new design of a hydraulic pulse vibrator with a valve pressure pulse generator of a parametric type has been developed, which allows determining its energy, power and geometric parameters. [ABSTRACT FROM AUTHOR]

Functional hypothalamic amenorrhea (FHA) is one of the most common causes of secondary amenorrhea, resulting in anovulation and infertility, and is a low estrogen state that increases the risk of cardiovascular disease and impairs bone health. FHA is characterized by acquired suppression of physiological pulsatile gonadotropin‐releasing hormone (GnRH) release by the hypothalamus in the absence of an identifiable structural cause, resulting in a functional hypogonadotropic hypogonadism. FHA results from either decreased energy intake and/or excessive exercise, leading to low energy availability and weight loss—often in combination with psychological stress on top of a background of genetic susceptibility. The hypothalamic neuropeptide kisspeptin is a key component of the GnRH pulse generator, tightly regulating pulsatile GnRH secretion and the downstream reproductive axis. Here, we review the physiological regulation of pulsatile GnRH secretion by hypothalamic kisspeptin neurons and how their activity is modulated by signals of energy status to affect reproductive function. We explore endocrine factors contributing to the suppression of GnRH pulsatility in the pathophysiology of FHA and how hypothalamic kisspeptin neurons likely represent a final common pathway through which these factors affect GnRH pulse generation. Finally, we discuss the therapeutic potential of kisspeptin as a novel treatment for women with FHA. [ABSTRACT FROM AUTHOR]

The planar solid-state pulse-forming line (planar solid-state PFL) is an important solid-state device used in compact pulse power systems. Moreover, pulsed power systems constitute a crucial element within electroporation systems. In this paper, we present theoretical and simulation analyses of the influence of the ground electrode structure of the planar solid-state PFL on the edge electric field and thermal distribution of high-voltage electrodes and the design of a novel improved solid-state PFL (opposite-electrode PFL) that differs from the classic planar solid-state PFL (full-electrode PFL) in which the ground electrode covers the entire plane. The ground electrode of the opposite-electrode PFL is structured to be consistent with the high-voltage electrode and positioned directly opposite to enhance the withstand voltage capacity of the planar solid-state PFL. The simulation results show that when the ground electrode width is the same as the high-voltage electrode, the electric field strength at the edge of the electrodes is smaller. In the electrostatic field simulation, the edge electric field strength of the high-voltage electrode in the opposite-electrode PFL is smaller than that of the full-electrode PFL, which indicates that the opposite-electrode PFL may have a higher withstand voltage. The experimental results show that the opposite-electrode PFL has a higher withstand voltage than the full-electrode PFL, which verifies the correctness of the theoretical and simulation analyses. Furthermore, the opposite-electrode PFL surface temperature rise showed a better performance after running the same test repeatedly. The findings of this study are conducive to enhancing the maximum output voltage or compactness of pulsed power systems and highlight the additional potential for the utilization of solid-state pulse generators in electroporation systems. [ABSTRACT FROM AUTHOR]

Reproductive function in mammals depends on the ability of progesterone (P4) to suppress pulsatile gonadotrophin-releasing hormone (GnRH) and luteinizing hormone (LH) secretion in a homeostatic-negative feedback loop. Previous research identified that cells upstream from GnRH neurons expressing the nuclear progesterone receptor (PGR) are required for P4-negative feedback. However, the identity of these cells and the mechanism by which they reduce GnRH/LH pulsatile secretion is unknown. We aimed to address the hypothesis that PGR expressed by a neural population in the arcuate nucleus recently identified as the GnRH pulse generator, cells expressing kisspeptin, neurokinin B, and dynorphin (KNDy cells), mediate P4-negative feedback. To achieve this, we used female mice with the PGR gene conditionally deleted from kisspeptin cells (KPRKO mice) and observed a substantial decrease in the percentage of KNDy neurons coexpressing PGR messenger RNA (mRNA) (11% in KPRKO mice vs 86% in wild-type [WT] mice). However, KPRKO mice did not display changes in the frequency or amplitude of LH pulses in diestrus or estrus, nor in the ability of exogenous P4 to blunt a postcastration increase in LH. Further, mRNA expression of arcuate kisspeptin and dynorphin, which are excitatory and inhibitory to GnRH secretion, respectively, remained unaltered in KPRKO mice compared to WT controls. Together, these findings show that the near-complete loss of PGR signaling from KNDy cells does not affect negative feedback regulation of GnRH pulse generation in mice, suggesting that feedback through this receptor can occur via a small number of KNDy cells or a yet unidentified cell population. [ABSTRACT FROM AUTHOR]

This research introduces the design, implementation, and rigorous evaluation of a novel 2-channel, multi-functional therapeutic electrical stimulator, meticulously engineered to meet the stringent demands of contemporary clinical applications. The device integrates a high-speed R-2R ladder DAC and a sophisticated pulse generator unit, capable of producing twelve essential current waveforms with fully adjustable parameters, including pulse amplitude, pulse duration, and pulse repetitive frequency. The proposed driving stage unit ensures precise voltage-to-current conversion, delivering stable and accurate output currents even under varying load conditions, which effectively simulate the diverse impedance characteristics of human tissue. Extensive testing confirmed the compliance with international medical standards, notably IEC 60601-1, IEC 60601-1-2, and IEC 60601-2-10. The experimental results underscore the device's consistent operation within prescribed safety and performance thresholds, with all deviations in pulse parameters remaining well below the permissible limits. Furthermore, the proposed electrical stimulator demonstrated exceptional stability across variable load conditions, as evidenced by minimal amplitude errors and high correlation between waveform characteristics. These findings highlight the proposed device's robustness and its potential as a versatile tool for a wide range of therapeutic applications, including pain management, muscle stimulation, and nerve rehabilitation, thus marking a significant advancement in the field of therapeutic electrical stimulation. [ABSTRACT FROM AUTHOR]

Vector inversion generators or spiral generators are compact, high voltage pulse generators consisting of a pair of conducting foils wound in a spiral and a switch. We developed an improved analytical model predicting the time evolution of the output voltage of such spiral generators. Our model (i) takes into account that the current in the switch results from the current on active and passive waveguides and (ii) takes into account the losses of the conductor in equations describing the propagation of voltage and current pulses in both waveguides. The model is compared to experimental results involving different input switches and at different temperatures to investigate the influence of resistive losses on the output voltage. The model is further developed to obtain the time evolution of the current in the switch. Our model is then used to predict the amplitude of the first two peaks of the oscillatory response of spiral generators as a function of a set of dimensionless parameters. [ABSTRACT FROM AUTHOR]

The results of the study of radiation produced by the electrical explosion of Al foil with a thickness of 4 μm with an artificial periodic structure of periodic holes with 50–400 μm steps created by laser engraving are presented. The experiments were carried out on a KING pulse high-current generator (220 kA, 40 kV, 300 ns). Images of exploded foils were recorded using pinhole cameras with a 20 μm aperture on a four-frame microchannel plate camera with 5 ns temporal resolution. In experiments on the electrical explosion of thin foils, it was shown that the application of an artificial periodic structure to the foil leads to a much more uniform radiation in the UV spectrum range along the entire length and width of the foil. Uniform radiation was observed from 20 to 70 ns. It is shown that such radiation can be used for the imaging of test objects or plasma objects like exploded wires. [ABSTRACT FROM AUTHOR]

The aim of the study was to test the performance of a silver wire modified version of the coded telemetric heart rate monitor Polar Vantage NV™ (PVNV) and to measure heart rate (HR) in a group of captive reindeer calves during different behaviour. The technical performance of PVNV HR monitors was tested in cold conditions (-30°C) using a pulse generator and the correlation between generated pulse and PVNV values was high (r = 0.9957). The accuracy was tested by comparing the HR obtained with the PVNV monitor with the standard ECG, and the correlation was significant (r = 0.9965). Both circadian HR and HR related to behavioural pattern were recorded. A circadian rhythm was observed in the HR in reindeer with a minimum during night and early morning hours and maximum at noon and during the afternoon, the average HR of the reindeer calves studied being 42.5 beats/min in February. The behaviour was recorded by focal individual observations and the data was synchronized with the output of the HR monitors. Running differed from all other behavioural categories in HR. Inter-individual differences were seen expressing individual responses to external and internal stimuli. The silver wire modified Polar Vantage NV™ provides a suitable and reliable tool for measuring heart rate in reindeer, also in natural conditions. [ABSTRACT FROM AUTHOR]

This paper presents a non-return-to-zero (NRZ)/4-level pulse amplitude modulation (PAM-4) dual-mode wireline transmitter with an eye-opening enhancement technique to improve horizontal eye-opening. With the eye-enhancement pulse generator and the auxiliary pull-up device in the tail-less current-mode driver, the worst-case horizontal eye-opening increased by 30% in the PAM-4 eye diagram. The power efficiency of the NRZ mode was also improved by completely turning off the LSB path in the differential data path, resulting in only a 31% power efficiency degradation, which is far lower than that of the prior dual-mode transmitters. Fabricated in 28 nm CMOS, the transmitter achieves power efficiency of 1.4 pJ/bit at 56 Gb/s in PAM-4 mode and 1.84 pJ/bit at 28 Gb/s in NRZ mode, respectively. [ABSTRACT FROM AUTHOR]

Pulse generators with high voltage and several nanoseconds of rise time are typically used to carry out the equivalent assessment of the protection performance of typical power equipment in the high-altitude electromagnetic pulse environment. In this paper, a pulse generator with high voltage and fast rise time has been designed, and the diagnostic system with high temporal resolution has been integrated to measure the output pulse voltage of the generator. The experimental results showed that the output pulse voltage of the generator on the output load can reach 645 kV when the charged voltage of Marx generator capacitors is 40 kV. The rise time of the generator is 8.2–9.9 ns when the charged voltage of Marx generator capacitors is in the range of 20–40 kV. [ABSTRACT FROM AUTHOR]

Single-photon avalanche diodes (SPADs) belong to a family of avalanche photodiodes (APDs) with single-photon detection capability that operate above the breakdown voltage (i.e., Geiger mode). Design and technology constraints, such as dark current, photon detection probability, and power dissipation, impose inherent device limitations on avalanche photodiodes. Moreover, after the detection of a photon, SPADs require dead time for avalanche quenching and recharge before they can detect another photon. The reduction in dead time results in higher efficiency for photon detection in high-frequency applications. In this work, an electronic interface, based on the pole-zero compensation technique for reducing dead time, was investigated. A nanosecond pulse generator was designed and fabricated to generate pulses of comparable voltage to an avalanche transistor. The quenching time constant (τq) is not affected by the compensation capacitance variation, while an increase of about 30% in the τq is related to the properties of the specific op-amp used in the design. Conversely, the recovery time was observed to be strongly influenced by the compensation capacitance. Reductions in the recovery time, from 927.3 ns down to 57.6 ns and 9.8 ns, were observed when varying the compensation capacitance in the range of 5–0.1 pF. The experimental results from an SPAD combined with an electronic interface based on an avalanche transistor are in strong accordance, providing similar output pulses to those of an illuminated SPAD. [ABSTRACT FROM AUTHOR]

Background: Peripheral Nerve Stimulation (PNS) is an established therapy for chronic neuropathic pain of peripheral origin, typically following nerve injury. However, there is a paucity of Randomized Controlled Trials (RCTs) demonstrating the therapeutic benefits of PNS. The goals of the current study (COMFORT Study) are to document the safety and efficacy of the Nalu Neurostimulation in a PNS RCT, compared to conventional medical management (CMM). Methods/Design: This is a prospective, multicenter, RCT evaluating the treatment of neuropathic pain with PNS therapy. One of the following four regions will be targeted for treatment: low back, shoulder, knee or foot/ankle. Consented subjects will undergo a baseline evaluation, after which they are randomized 2:1 (PNS+CMM arm to CMM arm). Subjects randomized to PNS+CMM arm will undergo a trial implant period using best clinical practices. Subjects who pass the trial phase, by showing a ≥ 50% reduction in pain relative to baseline, will receive the permanent implant. All subjects receiving a permanent implant will be followed for a total of 36 months. At the 3-month primary end point, subjects in CMM arm will be given the option to crossover into PNS+CMM arm, beginning with a trial implant. The study duration is expected to be 5.5 years from first enrollment to last follow-up of last subject and subsequent study closure. Adverse events will be captured throughout the study. Discussion: The COMFORT study, described here, has the potential to demonstrate the efficacy and safety of the Nalu Neurostimulation System in the treatment of peripheral neuropathy. Results of this study will be the first Level-I evidence, out to 36 months, validating the use of this PNS system in the treatment of chronic pain. This study is designed to enroll the largest cohort, to date, of subjects comparing PNS+CMM vs CMM alone. Plain Language Summary: Peripheral nerve stimulation (PNS) has been used for decades to treat neuropathic pain of peripheral origin. This therapy typically involves the placement small (~1 mm diameter) cylindrical electrodes (leads) near the nerve(s) in question, which is then followed by the delivery mild electrical pulses to the target, thereby blocking the pain signal from reaching the central nervous system. Despite the clinical success of this approach, there are few randomized controlled trials (RCTs) demonstrating PNS efficacy in the treatment of peripheral neuralgia/neuropathy. This may be, in large part, due to a paucity of PNS devices that are small enough to deliver this therapy at multiple locations in the extremities and the torso. For example, most implantable pulse generators (IPGs) range in size from 14 to 40 cm3 in volume. The purpose of this RCT is to demonstrate the safety and efficacy of an externally powered micro-IPG (< 1.5 cm3 in volume), in the delivery of PNS to treat peripheral neuropathic pain. Active Arm subjects will receive therapy with the micro-IPG and continue to use conventional medical management (CMM); Control Arm subjects will be treated with CMM only. The primary endpoint is the responder rate at 3-months, in both arms, defined as the percentage of subjects with ≥ 50% pain reduction from baseline following implantation of the micro-IPG. Control Arm subjects will be given the option to crossover to the Active Arm at 3-months. Study subjects in both arms are followed out to 36 months. [ABSTRACT FROM AUTHOR]

Psychological stress is linked to infertility by suppressing the hypothalamic GnRH pulse generator. The posterodorsal subnucleus of the medial amygdala (MePD) is an upstream regulator of GnRH pulse generator activity and displays increased neuronal activation during psychological stress. The MePD is primarily a GABAergic nucleus with a strong GABAergic projection to hypothalamic reproductive centers; however, their functional significance has not been determined. We hypothesize that MePD GABAergic signalling mediates psychological stress–induced suppression of pulsatile LH secretion. We selectively inhibited MePD GABA neurons during psychological stress in ovariectomized (OVX) Vgat-cre-tdTomato mice to determine the effect on stress-induced suppression of pulsatile LH secretion. MePD GABA neurons were virally infected with inhibitory hM4DGi-designer receptor exclusively activated by designer drugs (DREADDs) to selectively inhibit MePD GABA neurons. Furthermore, we optogenetically stimulated potential MePD GABAergic projection terminals in the hypothalamic arcuate nucleus (ARC) and determined the effect on pulsatile LH secretion. MePD GABA neurons in OVX female Vgat-cre-tdTomato mice were virally infected to express channelrhodopsin-2 and MePD GABAergic terminals in the ARC were selectively stimulated by blue light via an optic fiber implanted in the ARC. DREADD-mediated inhibition of MePD GABA neurons blocked predator odor and restraint stress-induced suppression of LH pulse frequency. Furthermore, sustained optogenetic stimulation at 10 and 20 Hz of MePD GABAergic terminals in the ARC suppressed pulsatile LH secretion. These results show for the first time that GABAergic signalling in the MePD mediates psychological stress–induced suppression of pulsatile LH secretion and suggest a functionally significant MePD GABAergic projection to the hypothalamic GnRH pulse generator. [ABSTRACT FROM AUTHOR]

The amino acid transmitter γ-aminobutyric acid (GABA) is suspected to play an important role in regulating the activity of the gonadotropin-releasing hormone (GnRH) neurons controlling fertility. Rodent GnRH neurons have a novel dendritic compartment termed the " distal dendron " through which action potentials pass to the axon terminals and where inputs from the kisspeptin pulse generator drive pulsatile GnRH secretion. Combining Gnrh1- Cre mice with the Cre-dependent calcium sensor GCaMP6 and confocal imaging of acute brain slices, we examined whether GABA regulated intracellular calcium concentrations ([Ca2+]) in the GnRH neuron distal dendron. Short puffs of GABA on the dendron evoked either a monophasic sustained suppression of [Ca2+] or a biphasic acute elevation in [Ca2+] followed by the sustained suppression. Application of muscimol to the dendron replicated the acute elevation in [Ca2+] while baclofen generated the sustained suppression. Robust GABAB receptor-mediated inhibition was observed in 80% to 100% of dendrons recorded from females across the estrous cycle and from approximately 70% of dendrons in males. In contrast, the GABAA receptor–mediated excitation was rare in males and varied across the estrous cycle, being most prominent at proestrus. The activation of GABAB receptors potently suppressed the stimulatory effect of kisspeptin on the dendron. These observations demonstrate that the great majority of GnRH neuron distal dendrons are regulated by GABAergic inputs in a sex- and estrous cycle–dependent manner, with robust GABAB receptor-mediated inhibition being the primary mode of signaling. This provides a new, kisspeptin-independent, pathway for the regulation of pulsatile and surge modes of GnRH secretion in the rodent. [ABSTRACT FROM AUTHOR]

To achieve fast and precise position servo control in a continuous-wave pulse generator and address issues such as internal and external disturbances and significant overshoot, this paper proposes an improved linear active disturbance rejection control strategy. First, a mathematical model of the permanent magnet synchronous motor is established, and a second-order linear active disturbance rejection controller is designed based on this model. To address the issue of large errors in disturbance estimation by the traditional extended state observer, a cascaded extended state observer is introduced. By designing an additional state observer to estimate the system's residual disturbances, the impact of disturbances on system performance is further reduced. Through an in-depth analysis of the motion characteristics of the continuous-wave pulse generator, the trade-off between system overshoot and response speed is revealed. To address this, a new adaptive law is proposed. This law, based on the system's periodic wave response and tracking error, adjusts the parameters of the linear state error feedback control law in real time, reducing system overshoot while improving response speed. To validate the effectiveness of the proposed control strategy, a simulation model of the position servo control system for the continuous-wave pulse generator was developed. The comparative analysis of the simulation results for the different control strategies shows that the improved linear active disturbance rejection control strategy significantly enhances the system's dynamic response performance. [ABSTRACT FROM AUTHOR]

This paper presents a high-frequency (HF) magnetic pulse generator designed for low-intensity transcranial magnetic stimulation (LI-TMS) applications. HF pulse stimulation can induce a strong electric field with minimal current and enhance the penetration depth of the electric field in human tissue. The HF magnetic pulse generator was designed and fabricated using a microcontroller unit, gate driver, full-bridge coil driver, and stimulation coil. Measurements with a full-bridge circuit supply voltage of 10 V demonstrated an electric field intensity of 6.8 Vpp/m at a frequency of 1 MHz with a power dissipation of 2.45 W. Achieving a similar electric field intensity at a frequency of 100 kHz required approximately ten times the coil current. Additionally, a quasi-resonant LC load was introduced by connecting a capacitor in series with the stimulation coil, which set the resonant frequency to approximately 10% higher than the frequency of 1 MHz. This approach reduced the coil impedance, achieving higher current with the same bias supply voltage. Experimental results showed an enhanced electric field intensity of 19.1 Vpp/m with a supply voltage of only 1.8 V and reduced power dissipation of 1.11 W. The proposed HF pulse train with quasi-resonant coil system is expected to enable a low-power LI-TMS system. [ABSTRACT FROM AUTHOR]

We investigated a time-delayed optoelectronic oscillator (OEO) that displays a wide range of complex dynamic behavior under small time delay. The phase-space trajectory distributions in different dynamic regimes were compared which brings a new perspective on the underlying mechanism of the transition process. It was found that bifurcation is always possible no matter how small the time delay is even if the universal adiabatic approximation model is invalid. Hereby we proposed a versatile simple oscillator which has a potential capacity as memory carrier and high-dimensional state spatial mapping ability that brings 1000 times computing-efficiency improvements of reservoir computing over the large time delay one. Furthermore, we demonstrated a new approach for a tunable optoelectronic pulse generator (repetition rate at 0.2 MHz and 0.25 GHz) which depends critically on time-delayed input electrical pulse. The proposed oscillator is also a promising system for the applications of fast chaos-based communication. [ABSTRACT FROM AUTHOR]

Electrospray thrusters exhibit diverse operational modes based on the nature of ejected particles. Time-of-flight mass spectrometry is frequently employed to analyze the composition of the plume. This study introduces a novel converter-based bipolar high-voltage pulse generator aimed at producing synchronized bipolar high-voltage pulses with controllable voltage levels and frequencies, specifically tailored for the study of electrospray thrusters. The proposed topology generates bipolar high-voltage rails from a low-voltage power source through the forward–flyback with Cockcroft–Walton voltage multiplier topology. Subsequently, fast high-voltage MOSFETs are employed to generate high-voltage pulses. This paper outlines the operational principles and design methodologies of the pulse generator. Experimental verification corroborates its operational principles and functionalities, revealing that the pulse rise and fall times consistently remain below 30 ns, while the voltage can be tuned within the range of 300–1000 V. An electrospray thruster was employed to conduct a thorough and practical validation of the high-voltage pulse generator. This included generating time-of-flight curves and mass spectra of the plume, resulting in precise differentiation of all particles present. [ABSTRACT FROM AUTHOR]

Background and purpose: Deep brain stimulation (DBS) is a surgical procedure that has been used to treat a variety of neurological disorders including Parkinson's disease, essential tremor, and dystonia. While DBS is generally considered safe and effective, surgical site infections (SSIs) are a potential complication that can lead to significant morbidity and mortality. Our objective was to investigate the use of antibiotic-impregnated envelopes (AIEs) encasing implantable pulse generators (IPGs) to reduce the rate of infection at IPG sites and the costs. Methods: We conducted a retrospective analysis at a single center encompassing all procedures involving the placement of Implantable Pulse Generators (IPG), including both initial insertions and replacement surgeries. The study period spanned from January 2017 to May 2024. Starting in 2020, the routine utilization of AIE became standard practice at our institute for both primary DBS implantation and IPG replacements. Surgical techniques remained consistent, pre- and post-operative antibiotic protocols were standardized throughout the study period and all cases were undertaken by a single surgeon. Results: 178 patients were included and the overall incidence of IPG SSIs was found to be 1.7% (1 infection in 58 patients; 20 primary IPG/38 IPG replacements) among those who received an AIE compared to 5% (6 infections in 120 patients; 36 primary IPG/84 replacement IPG) in patients where no AIE was utilized. This resulted in an odds ratio for infection that was 2.9 times higher in the absence of AIE. The decrease in infection rates was observed in both primary and replacement IPG implants. Notably, over 80% of patients with IPG infection required surgical intervention. The use of AIE further resulted in significant cost savings. Conclusion: To our knowledge, this is the largest series reporting the efficacy of Antibiotic impregnated envelope (AIE) in modifying infection rates associated with both initial and replacement Deep Brain Stimulation (DBS) Implantable Pulse Generators (IPGs). The implementation of AIEs led to a decrease in the occurrence of IPG-related infections, observed across both primary implantations and replacement surgeries, with associated economic benefits. [ABSTRACT FROM AUTHOR]

It was studied how the geometrical parameters of an X-pinch (the angle of inclination of the wires to the X-pinch vertical axis and the length of the electrode gap) affected the number of hot spots, formed in the region of the X-pinch neck, and the x-ray yield. The experiment was performed on the XPG-3 compact current pulse generator (180 kA, 180 ns). The highest values of the x-ray energy per pulse were observed when the angle of inclination of the wires to the X-pinch load vertical axis (z-axis) was 40°–45° at an electrode gap length of 6–7 mm. In these cases, the energy of the x-ray pulse in the spectral range hν = 1.5–5 keV was 1.1 ± 0.4 J. The angle of inclination of the X-pinch wires to the z-axis equal to 45° was a threshold above which the conditions for the formation of a hot spot changed significantly. It was observed that, regardless of the wire inclination angle, two hot spots formed with a high degree of probability in the neck region at the final stage of implosion. [ABSTRACT FROM AUTHOR]

The radial pulse is a critical health marker with expanding applications in wearable technology. To improve these applications, developing a pulse generator that consistently produces realistic pulses is crucial for validation and training. The goal of this study was to design and test a cost-effective pulse simulator that can accurately replicate a wide range of age-dependent radial pulses with simplicity and precision. To this end, this study incorporated a magneto-rheological (MR) fluid device into a cam-based pulse simulator. The MR device, as a key component, enables pulse shaping without the need for additional cams, substantially reducing the cost and complexity of control compared with existing pulse simulators. To evaluate the performance of the MR pulse simulator, the root-mean-square (RMS) error criterion (less than 5%) was used to compare the experimentally obtained pulse waveform with the in vivo pulse waveform for specific age groups. After demonstrating that the MR simulator could produce three representative in vivo pulses, a parametric study was conducted to show the feasibility of the slope-based pulse-shaping method for the MR pulse simulator to continuously generate a range of age-related pulses. [ABSTRACT FROM AUTHOR]

In this study, the on‐chip generation of microwave signals are proposed for controlling nearby quantum bits in a low‐temperature environment, utilizing superconducting logical and RF components. To achieve enhanced amplitude of the microwave, superconducting single flux quantum (SFQ) pulse pairs are employed, which can have either the same or reversal polarity, serving as the basic elements of the generator. The SFQ pulse pairs are then combined and wave‐shaped by using a microwave combining filter, which finally outputs desired microwave signals with narrow line‐width. The amplitude of the microwave signal correlates with the interval between two SFQ pulses in a pair and can be adjusted accordingly. To validate the proposal, test chips are fabricated and performed experiments. The experimental results confirm that the method using a reverse‐polarity pulse can maximize the output microwave amplitude and provide control of the initial phase of the output microwave. This improvement offers a superior alternative for generating microwaves using superconducting circuits to control quantum bits. [ABSTRACT FROM AUTHOR]

Substance use disorders are prevalent, causing extensive morbidity and mortality worldwide. Evidence-based treatments are of low to moderate effect size. Growth in the neurobiological understanding of addiction (e.g., craving) along with technological advancements in neuromodulation have enabled an evaluation of neurosurgical treatments for substance use disorders. Deep brain stimulation (DBS) involves surgical implantation of leads into brain targets and subcutaneous tunneling to connect the leads to a programmable implanted pulse generator (IPG) under the skin of the chest. DBS allows direct testing of neurobiologically-guided hypotheses regarding the etiology of substance use disorders in service of developing more effective treatments. Early studies, although with multiple limitations, have been promising. Still the authors express caution regarding implementation of DBS studies in this population and emphasize the importance of safeguards to ensure patient safety and meaningful study results. In this perspectives article, we review lessons learned through the years of planning an ongoing trial of DBS for methamphetamine use disorder. [ABSTRACT FROM AUTHOR]

In this scientific paper, we have considered a method for determining the complex reflection coefficient based on spectral analysis of the output voltage of a parametric microwave converter. [ABSTRACT FROM AUTHOR]

Electric fields are used in biology to address a broad range of questions and through a variety of techniques, including electroporation, gene electrotransfer (GET), electrostimulation (ES), and electrochemotherapy. Each of these modalities requires specific conditions and has drastically different target outcomes on the cell. ES has demonstrated that non-pore forming electric fields alter cell cycle progression. However, pore forming electric fields such as with GET have not been as widely explored despite major clinical advancements. Additionally, the real-time visual analysis of electrical field effects on mammalian cell culture is currently lacking among most commercial systems. To facilitate investigations into these research areas, an electroporation cytometry system was developed including a custom chamber compatible with live cell imaging and exponential decay pulse generator for live cell analysis. The functionality of the system was demonstrated using a recombinant cell line using U-2 OS cells and FUCCI(CA)5 cell cycle reporter. The exposure of the cells to a 180 V pulse in both unsynchronized and synchronized populations revealed an effect on the cell cycle. [ABSTRACT FROM AUTHOR]

Background: Remote programming (RP) is an emerging technology that enables the adjustment of implantable pulse generators (IPGs) via the Internet for people with Parkinson's disease (PwPD) who have undergone deep brain stimulation (DBS). Previous studies have not comprehensively explored the effectiveness of RP in managing motor symptoms, often omitting assessments such as the rigidity and retropulsion tests during the follow-up. This study evaluates the comprehensive improvements in motor performance and the potential cost benefits of RP for PwPD with DBS. Methods: A retrospective analysis was conducted on two groups of patients--those who received RP and those who received standard programming (SP). Clinical outcomes including motor improvement, quality of life, and daily levodopa dosage were compared between the groups during a 12 (± 3)-month in-clinic follow-up. Results: A total of 44 patients were included in the study, with 18 in the RP group and 26 in the SP group. No significant differences were observed in the frequency of programming sessions or clinical outcomes between the groups (p > 0.05). However, the RP group experienced significantly lower costs per programming session than the SP group (p < 0.05), despite patients in the former group living further from our center (p < 0.05). Conclusions: Our findings suggest that RP could significantly reduce the costs of programming for PwPD with DBS, especially without compromising the effectiveness of treatment across all motor symptoms in the short term. [ABSTRACT FROM AUTHOR]

Background When cardiac implantable electronic device infection occurs, standard therapy is usually total system extraction. Transvenous lead extraction is preferable to open heart surgical extraction, unless contraindicated because of the presence of very large vegetations on the intravenous leads according to the European Society of Cardiology guidelines. Extraction of transvenous leads with vegetations risks distal embolism resulting in obstruction and/or infection in the pulmonary arteries. Catheter aspiration of vegetations or thrombi has been performed prior to transvenous lead extraction using a partial veno-venous extracorporeal bypass circuit. We report the use of a single-access aspiration system using the Inari FlowTriever 24 French system to debulk a defibrillator lead before percutaneous extraction. Case summary A 79-year-old male presented with fever 18 years after his first implantable cardioverter defibrillator implant and 9 years after his most recent pulse generator change. Two large vegetations were identified on his transvenous defibrillator lead on the atrial aspect, near the tricuspid annulus, which were aspirated using the Inari Medical 24Fr FlowTriever aspiration catheter. We describe anatomical considerations during the approach and a technique to localize the vegetations based on a combination of fluoroscopy and transoesophageal echocardiogram guidance. Discussion This case demonstrates the safe and effective use of the Inari Medical 24Fr FlowTriever aspiration catheter in debulking a defibrillator lead before transvenous lead extraction. This method uses a single venous puncture and is not dependent on extracorporeal bypass. Apart from reducing complexity, this technique may be advantageous in patients where anticoagulation needs to be minimised. [ABSTRACT FROM AUTHOR]

The physiology of reproduction has been of interest to researchers for centuries. The purpose of this work is to review the development of our knowledge on the neuroendocrine background of the regulation of ovulation. We first describe the development of the pituitary gland, the structure of the median eminence (ME), the connection between the hypothalamus and the pituitary gland, the ovarian and pituitary hormones involved in ovulation, and the pituitary cell composition. We recall the pioneer physiological and morphological investigations that drove development forward. The description of the supraoptic–paraventricular magnocellular and tuberoinfundibular parvocellular systems and recognizing the role of the hypophysiotropic area were major milestones in understanding the anatomical and physiological basis of reproduction. The discovery of releasing and inhibiting hormones, the significance of pulse and surge generators, the pulsatile secretion of the gonadotropin-releasing hormone (GnRH), and the subsequent pulsatility of luteinizing (LH) and follicle-stimulating hormones (FSH) in the human reproductive physiology were truly transformative. The roles of three critical neuropeptides, kisspeptin (KP), neurokinin B (NKB), and dynorphin (Dy), were also identified. This review also touches on the endocrine background of human infertility and assisted fertilization. [ABSTRACT FROM AUTHOR]

Nonlinear transmission lines with ferrite have been actively developed and studied for about two decades. At the same time, the first works on this topic date back to the middle of the last century. Nonlinear transmission lines with ferrite find their application in various problems of electrophysics, with the greatest application being found in the problems of pulse sharpening, as delay lines and generators of highpower pulses of microwave radiation. The main scientific and technical results of the development of technologies of nonlinear transmission lines with ferrite are presented in chronological order, starting from lines for sharpening the fronts of voltage pulses, ending with multichannel microwave sources based on them. [ABSTRACT FROM AUTHOR]

Summary: In the case of future access networks, such as 6G‐based applications, the free‐space optical communication (FSO) technology is an efficient solution. FSO in 6G is extremely popular because of its unique properties, which include ease of installation, high bandwidth, high security, license‐free long range, and interference resistance. However, environmental disturbances have a negative impact on the FSO system's functioning. Because of these atmospheric turbulences, the optical information gets restricted, which in turn reduces the link reliability, power density, and distance. This paper proposes a hybrid FSO strategy for improving system efficiency to address these problems. Signal creation is fundamental to every successful communication system. The FSO system consists of three components: the transmitter, the channel medium, and the receiver. The transmitter section includes a continuous wave laser, a Mach–Zehnder modulator, a nonreturn to zero transpose Walsh code generator, and a nonreturn to zero pulse generator. Wavelength division multiplexing‐optical code division multiple access‐spectrum slicing (WDM‐OCDMA‐SS) is used to facilitate efficient data transfer after signals have been generated by alternate mark inversion (AMI). In order to boost a weak signal, fused Raman erbium amplifiers (Fuse‐RE) are used. Q factor and log bit error rate (BER) are used to assess the performance of the suggested approach. The proposed model has obtained a log BER of −15.3291 for clear air and a Q factor of 8.2922, whereas the performances are implemented using Python. The proposed approach achieves better performance when compared to the existing methodologies. [ABSTRACT FROM AUTHOR]

Despite the extensively researched physical principles, numerous published simulations on SiC drift step recovery diodes (SiC DSRD) and the practical implementation of SiC DSRD-based pulses, there are few kinds of research focusing on collaborative design between a SiC DSRD and its driving circuit. In this paper, a collaborative design method of a SiC DSRD and its driving circuit are presented. In addition, a detailed simulation is conducted to verify design considerations and to analyze the impact of driving parameter changes on the output pulse waveform. A pulse generator prototype with a self-developed SiC DSRD is implemented. The experimental results show that the circuit can output a peak voltage of 790 V on a matching load of 50 Ω, with a rise time of 520 ps (20%~80%), and can work at a 1 MHz repetition frequency rate with good stability. [ABSTRACT FROM AUTHOR]

High voltage (HV) generators are used in multiple industrial and scientific facilities. Recent publications have demonstrated that triggering industrial thyristors (relatively slow switching devices) in overvoltage mode, also called impact ionization mode, significantly enhances their dU/dt and dI/dt characteristics. This novel triggering methodology necessitates the application of substantial overvoltage between the thyristor's anode and cathode, delivered with a swift slew rate exceeding 1 kV/ns. The adoption of compact pulse generators constructed from commercially available off-the-shelf components (COTS) opens up avenues for deploying this technology across various domains, including the implementation of high-speed kicker generators in particle accelerators. In our methodology, we employed commercially available high-voltage SiC MOSFETs along with a custom-designed fast gate driver. This driver was conceptualized based on the recent development of gate boosting techniques, featuring a driving voltage exceeding 600 V. The gate driver for these MOSFETs comprises three key components: a level-shifter with NMOS and PMOS transistors, a compact Marx generator with two avalanche transistors, and a GaN HEMT in a high input and low output impedance configuration. The proposed gate-boosting driver achieves a slew rate exceeding 1 kV/ns for the driving pulse. Furthermore, we demonstrate that with this driver, a  1.7  kV rated SiC MOSFET can produce an output pulse of  1.45  kV and a maximum slew rate of ≈ 2.5  kV/ns. This gate-boosting driver aims to minimize commutation times, achieves a slew rate of over 1 kV/ns, and handle higher loads, making it ideal for impact ionization triggering of industrial thyristors. [ABSTRACT FROM AUTHOR]

Resonator-based optical frequency comb generation is an enabling technology for a myriad of applications ranging from communications to precision spectroscopy. These frequency combs can be generated in nonlinear resonators driven using either continuous-wave (CW) light, which requires alignment of the pump frequency with the cavity resonance, or pulsed light, which also mandates that the pulse repetition rate and cavity free spectral range (FSR) are carefully matched. Advancements in nanophotonics have ignited interest in chip-scale optical frequency combs. However, realizing pulse-driven on-chip Kerr combs remains challenging, as microresonator cavities have limited tuning range in their FSR and resonance frequency. Here, we take steps to overcome this limitation and demonstrate broadband frequency comb generation using a χ(3) resonator synchronously pumped by a tunable femtosecond pulse generator with on-chip amplitude and phase modulators. Notably, employing pulsed pumping overcomes limitations in Kerr comb generation typically seen in crystalline resonators from stimulated Raman scattering. Here the authors use on-chip amplitude and phase modulation to synchronously pump a resonator on thin-film lithium niobate for frequency comb generation. They find that pulsed pumping significantly mitigates stimulated Raman scattering and improves the overall efficiency of the device. [ABSTRACT FROM AUTHOR]

The article presents a new experimental portable pulsed neutron generator based on a laser-plasma ion diode with magnetic insulation and the results of the first experiments. The laser-plasma diode makes it possible to obtain large ion current pulses that generate high-intensity neutron radiation. The source of optical radiation was a pulsed neodymium-doped yttrium aluminum garnet laser with a wavelength of 1064 nm, a pulse energy of up to 0.7 J, and a duration of ~10 ns. The ion beam is accelerated by an Arkadiev–Marx pulsed voltage generator with a voltage amplitude of up to 250 kV, a duration of up to 1.5 μs, and an energy of up to 160 J. Neutrons were generated using the reaction d(d, n) 3He. A neutron yield of 2 × 106 neutron/pulse was obtained. [ABSTRACT FROM AUTHOR]