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Laccase is a multicopper oxidase enzyme that oxidizes a variety of substrates, including polyphenols and polycyclic aromatic hydrocarbons (PAHs). It catalyzes the four-electron reduction of molecular oxygen that results in the production of water as a by-product. Thus, laccase can play an important role in environmental care. Previously, we have successfully expressed Trametes trogii laccase (TtLcc1) in the yeast Saccharomyces cerevisiae. In this work, we have expressed in yeast another laccase, LacA from Trametes sp. AH28-2, and tested its function on PAHs. Yeast cells engineered to produce the two laccases performed efficient PAH degradation. Both TtLcc1 and LacA led to the construction of spatiotemporal fluorescence-pulse generators when combined with a benzoate/salicylate yeast biosensor in a two-population system. Moreover, laccases returned a visual output signal in yeast synthetic circuits—upon reacting with ABTS (2,2′-azino-bis (3-ethylbenzthiazoline-6-sulfonic acid)). Thus, in S. cerevisiae, laccases are a powerful alternative to fluorescent reporter proteins.

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]

This study entailed the development of a complementary metal–oxide–semiconductor (CMOS) ultra-wideband (UWB) pulse generator with an inherent binary phase-shift keying (BPSK) modulation technique. The BPSK modulation technique in a pulsed oscillator has been proposed by the author in previous studies on K-band application. In this study, a W-band CMOS UWB pulse generator was developed using this technique. The W-band UWB pulse generator was implemented on a 0.13-μm CMOS chip with an active area of 0.08 mm² . The output spectrum exhibited a −10 dB bandwidth of 2.8 GHz, ranging from 75.1 to 77.9 GHz. The energy consumption was 45 pJ per pulse with a peak output power of −2.6 dBm [ABSTRACT FROM AUTHOR]

With the advancements in power semiconductors and converters, power electronics based high-voltage pulse generators (HVPG) have emerged due to their advantages of high repetition rate, flexible control, long lifetime, and compact size. However, there is a lack of comprehensive literature review on recent advances in power electronics intensive HVPG technologies. To fill this gap, we present a systematic review on HVPGs. First, HVPGs are classified into different types based on their mechanisms. Each type along with its basic circuits and modifications are introduced. Then, the characteristics, advantages, and disadvantages of these topologies are summarized. Furthermore, the potential applications of HVPGs are explored. The performance of pulse generators mentioned in the literature and commercial products is listed. Finally, future trends and technical challenges in HVPG design and development are discussed. This paper provides a clear understanding of HVPGs and the inspiration of topologies developments to meet the specific requirements. Current state and potential future directions are discussed and summarized to facilitate evolvements in HVPG technology.

In solid-state high-voltage pulse generators, switches may be triggered on by fault due to electromagnetic interference, resulting in high through current and breakdown of switches. To generate rectangular high-voltage pulses, this paper proposes a solid-state Marx generator (SSMG) with fast recovery diodes to prevent through current. Only charging currents with the same direction flow through these fast recovery diodes breaks the short-circuit loops in and between stages. A 52-stage SSMG prototype based on the proposed circuit was developed. PSpice simulations and experiments were performed for comparison. It was found that the through current can rise to 250 A without any protection. With 10-μH protection inductors in each state, the through current amplitude drops to 50 A. Under the same condition, there is no continuous through current with the proposed fast recovery diodes. Furthermore, 22-kV repetitive rectangular pulses were also obtained in experiments. This proved that the proposed Marx generator can prevent the through current in power cells. [ABSTRACT FROM AUTHOR]

Objective: Temporary permanent pacing (TPP) remains an underutilized yet crucial procedure involving active fixation leads connected to a pulse generator affixed to the patient's skin surface. We aim to conduct a retrospective study to examine the indications, duration, procedural complications, and outcomes of TPP interventions conducted at our center over a 2-year period. Methods: This is a retrospective, single-centre observational study done in the Department of Cardiology & Electrophysiology, Sri Jayadeva Institute of Cardiovascular Sciences & Research (SJICSR), a tertiary care medical centre in Bengaluru, Karnataka. This retrospective study examines the indications, duration, procedural complications, and outcomes of TPP interventions conducted at our centre over a 2-year period from December 2021 to December 2023. Results: Seventeen patients underwent TPP, with 64.6% necessitating pacing during the postexplant/extraction period due to device-related infections. Additionally, 11.8% presented with complete heart block (CHB) and sepsis, while another 11.8% were post-aortic valve replacement patients experiencing sepsis with transient atrioventricular block. Singular cases comprised a CHB patient with stroke (5.9%) and a pre-operative CHB patient (5.9%). The mean TPP duration was 18.5±6.7 days (range: 10 to 30 days). Complications included superficial skin infection (11.9%) and lead dislodgment (5.8%), with no recorded mortalities. Conclusion: Our findings, in conjunction with existing literature, affirm TPP as a safe and reliable pacing method for up to a one-month period. Encouraging education and broader adoption of TPP among emergency care providers and cardiologists is imperative. [ABSTRACT FROM AUTHOR]

In “Evaluation of 50 Ω driver circuits for digital signals based on oscilloscope measurements” (Heliyon, Volume 7, Issue 7, July 2021) different 50 Ω driver circuits for digital signals were compared and evaluated. Notably, the BJT-based discrete push-pull driver circuit showed a rather modest performance. It is also questionable whether the fast-switching signals of the individual driver circuits were reproduced completely and correctly with the PicoScope 3206A oscilloscope used in that study, as its sampling rate is quite low.For these reasons, the experiments were continued, several improvements were made to the test board. A new driver circuit was implemented on the test board, too. New measurement data were recorded both with a Tektronix MDO3024 oscilloscope and for comparison with the previously used PicoScope 3206A.The following dataset is made available: The revised test board (PCB layout and schematic design files), oscilloscope measurement data in CSV format, Python scripts for graphical representation of the CSV data.

The theoretical possibilities of increasing the resolution and sensitivity of a time-of-flight mass spectrometer with orthogonal ion injection are considered. The effects are achieved by using inhomogeneous electrostatic fields of special configurations both in the accelerating and focusing parts of the device – a cylindrical immersion objective and a transaxial mirror, respectively. It is shown that the use of an inhomogeneous cylindrical field of a special configuration as an ion accelerator opens up the possibility of a multiple reduction in the energy spread of ions in injected ion packets, associated with the so-called "turnaround time" and, therefore, a significant (two or more times) increase in the limiting resolution of the mass spectrometer. The use of a transaxial electrostatic mirror as a time-of-flight mass analyzer makes it possible to significantly increase the sensitivity of the mass-spectrometer due to the implementation of triple spacetime-of-flight focusing of ion packets. Key features include reduced ion energy spread, increased maximum resolution, and improved sensitivity due to triple focusing in space and time of flight. This research lays the foundation for expanding the capabilities of time-of-flight mass spectrometry, providing a more efficient and powerful tool for a wide range of scientific and industrial applications. The effects are achieved by using inhomogeneous electrostatic fields of a special configuration in both the accelerating and focusing parts of the device – a cylindrical immersion lens and a transaxial mirror, respectively. Numerical calculations of the system – a four-electrode cylindrical immersion lens in combination with a three-electrode transaxial mirror – are presented, which confirm the conclusions of the theory [ABSTRACT FROM AUTHOR]

Copyright of Large Electric Machine & Hydraulic Turbine is the property of Large Electric Machine & Hydraulic Turbine Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The current model for the synchronization of GnRH neural activity driving GnRH and LH pulses proposes that a set of arcuate (ARC) neurons that contain kisspeptin, neurokinin B, and dynorphin (KNDy neurons) is the GnRH pulse generator. This study tested the functional role of ovine KNDy neurons in pulse generation and explored the roles of nearby Kiss1 receptor (Kiss1R)-containing cells using lesions produced with saporin (SAP) conjugates. Injection of NK3-SAP ablated over 90% of the KNDy cells, while Kiss-SAP (saporin conjugated to kisspeptin-54) lesioned about two-thirds of the Kiss1R population without affecting KNDy or GnRH cell number. Both lesions produced a dramatic decrease in LH pulse amplitude but had different effects on LH pulse patterns. NK3-SAP increased interpulse interval, but Kiss-SAP did not. In contrast, Kiss-SAP disrupted the regular hourly occurrence of LH pulses, but NK3-SAP did not. Because Kiss1R is not expressed in KNDy cells, HiPlex RNAScope was used to assess the colocalization of 8 neurotransmitters and 3 receptors in ARC Kiss1R -containing cells. Kiss1R cells primarily contained transcript markers for GABA (68%), glutamate (28%), ESR1 (estrogen receptor-α) mRNA, and OPRK1 (kappa opioid receptor) mRNA. These data support the conclusion that KNDy neurons are essential for GnRH pulses in ewes, whereas ARC Kiss1R cells are not but do maintain the amplitude and regularity of GnRH pulses. We thus propose that in sheep, ARC Kiss1R neurons form part of a positive feedback circuit that reinforces the activity of the KNDy neural network, with GABA or glutamate likely being involved. [ABSTRACT FROM AUTHOR]

To meet the application requirements of pulsed power technology in wastewater treatment and other aspects (for example, a scenario that requires a high-voltage pulse source that can output a pulse with a rising edge in the nanosecond range and a device that can stabilize the pulse under high-frequency conditions), this paper designed an inductively isolated bipolar high-voltage pulse source. It consists of three parts: the primary charging power supply, the isolated driver circuit, and the pulse-forming circuit. By using inductance instead of traditional resistance isolation, using the inductance for charging and isolation, the inductance can increase the charging voltage of the capacitor, so the circuit can achieve a higher voltage output. The dual-Marx generator parallel connection design of the pulsed power supply topology, using a primary charging power supply for positive and negative polarity charging, can simultaneously output the reverse polarity and size of high-voltage pulses to achieve a bipolar output, so the load has an effect on the pulse. The equipment was selected on the basis of the design of the isolated driver circuit, primary charging power supply circuit, and pulse-forming circuit for the corresponding simulation, and in the experiment to build a principle model, the tests showed that the pulse source output pulse amplitude range was 0~10 kV (the positive pulse voltage was 5 kV, and the negative pulse voltage was −5 kV), the pulse rising edge was approximately 200 ns, the pulse width was 1 μs, and the frequency range was 0~1 kHz for the pulse source frequency. The power supply was designed to be used in applications such as wastewater treatment. [ABSTRACT FROM AUTHOR]

The use of high-frequency input signals from room-temperature microwave sources makes it difficult to scale up the number of quantum bits in universal quantum computers. To address this issue, superconducting single flux quantum (SFQ) integrated circuits are being explored as suitable candidates for qubit manipulation in universal quantum computers. This paper deals with a scalable SFQ qubit control circuit (SQCC) structure that requires only low-frequency input. The circuit mainly consists of a pulse generator and a counter, that output the SFQ pulse train with adjustable frequency and a controllable number of pulses, which is applicable to control single-qubit Clifford operations. The design of low-voltage rapid single flux quantum (LV-RSFQ) and energy-efficient rapid single flux quantum (ERSFQ) for the SQCC achieves low power consumption and provides a basis for scaling up SQCC to control more qubits. The proposed circuits are fabricated under the SIMIT-Nb03 process and successfully pass test verification. The achieved test results reveal that the adjustable output frequency ranges of the SQCC based on the LV-RSFQ and ERSFQ designs in order are [2.40, 8.11] GHz and [4.81, 5.14] GHz. In the operating frequency range, the circuit is able to generate the correct number of SFQ pulses under control. The controllable number range is from 1 to 128. When the circuits operate at 5 GHz, the total power consumptions of the above circuits in order are 23.88 μ W and 6.2 μ W. All input signals are low-frequency signals, which frees the control of large-scale qubits from limitations caused by high-frequency inputs produced by room-temperature microwave sources. [ABSTRACT FROM AUTHOR]

Uncovering the central mechanism underlying mammalian reproduction is warranted to develop new therapeutic approaches for reproductive disorders in humans and domestic animals. The present study focused on the role of arcuate kisspeptin neurones (also known as KNDy neurones) as an intrinsic gonadotropin‐releasing hormone (GnRH) pulse generator, which plays a fundamental role in mammalian reproduction via the stimulation of pituitary gonadotropin synthesis and release and thereby in gametogenesis and steroidogenesis in the gonads of mammals. We also discuss the mechanism that inhibits pulsatile GnRH/gonadotropin release under a negative energy balance, considering that reproductive disorders often occur during malnutrition in humans and livestock. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Mechanical Strength / Jixie Qiangdu is the property of Zhengzhou Research Institute of Mechanical Engineering and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

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.

Due to the severe impacts of climatic change, many recent developments in air cleaning systems have received an increasing attention. The best solution for expelling pollutant particles, met in industrial and commercial applications, is the electrostatic precipitator (ESP). One of the key components in the ESP system is the high-voltage power supply. Many recent studies have proven that the sectionalization of industrial ESPs enhances their particle collection efficiency. Consequently, this paper proposes a new modular switched-capacitor voltage multiplier-based multi-module high-voltage pulse power supply. In the proposed configuration, the two different patterns of output pulse are adopted. The proposed scheme is characterized by its modular structure and its capability of providing two isolated high-voltage pulse generators for each two ESP bus sections from one low-voltage AC source with an adjustable repetition rate, a controllable pulse width, and the desired values of the base and pulse voltages. A detailed illustration and simulation results are presented for the proposed approach. A comparative study is presented to elucidate the advantages of the proposed topology in contrast with the existing topologies. Finally, a -1.2-kV, 0.36-kW experimental setup has been built to show the viability of the proposed concept.

The vertical well inclinometer is widely used in downhole data measurement, wherein the mud pulse generator used for data transmission has substantial significance to the accuracy and stability of data. For this instrument, the performance of its mud pulse generator valve head is the key to ensure the efficient, accurate and complete transmission of downhole data. Firstly, the structure of pulse generator in the vertical well inclinometer is described, followed by the presentation of the physical and theoretical model of pulse generator valve head. Based on the erosion theories and thin-wall hole throttling model, the main parameters that affect the performance of pulse generator valve head are determined, including the throttling hole slot angle α and the valve head angle β. Secondly, with using the discrete phase model（DPM）, the influences of throttle slot angle α and valve head angle β on the flow field characteristics near the valve head and the pressure distribution of the valve head are investigated. In terms of the simulation, an optimized parameter set of the valve head is α=25°and β=45°. Finally, valve heads with optimized parameters are tested in a certain well of Dixi, showing a good accuracy with the numerical simulation with comparing the results before optimization.

Due to the severe impacts of climatic change, many recent developments in air cleaning systems have received an increasing attention. The best solution for expelling pollutant particles, met in industrial and commercial applications, is the electrostatic precipitator (ESP). One of the key components in the ESP system is the high-voltage power supply. Many recent studies have proven that the sectionalization of industrial ESPs enhances their particle collection efficiency. Consequently, this paper proposes a new modular switched-capacitor voltage multiplier-based multi-module high-voltage pulse power supply. In the proposed configuration, the two different patterns of output pulse are adopted. The proposed scheme is characterized by its modular structure and its capability of providing two isolated high-voltage pulse generators for each two ESP bus sections from one low-voltage AC source with an adjustable repetition rate, a controllable pulse width, and the desired values of the base and pulse voltages. A detailed illustration and simulation results are presented for the proposed approach. A comparative study is presented to elucidate the advantages of the proposed topology in contrast with the existing topologies. Finally, a - 1.2 -kV, 0.36 -kW experimental setup has been built to show the viability of the proposed concept. [ABSTRACT FROM AUTHOR]

Ultra-wideband (UWB) technology has been applied in many fields, such as radar and indoor positioning, because of its advantages of having a high transmission rate, anti-multipath interference, and good concealment. In the UWB physical layer, the transmitting link, including an encoder and a pulse generator, is used to improve the anti-interference ability of the signal, while the receiving link, including a receiver and a decoder, can correct the error signal. Therefore, the performance of the UWB physical layer can obviously affect the speed and quality of UWB signal transmission. In this paper, the structure and performance of the codec and transceiver of the UWB physical layer are introduced and compared. In addition, some typical architectures and features are summarized and discussed, which provides a valuable reference and suggestions for the design of the UWB physical layer. Finally, the outlook of the UWB physical layer is presented: its development direction mainly includes high speed, low power consumption, and fewer hardware resources. [ABSTRACT FROM AUTHOR]

We present an alternative technique of monosex-male reversal for Nile tilapia using transient square pulse-electric field inductions to enhance sex reversal rate of tilapia eggs by methyltestosterone (Oreochromis niloticus L., Chitralada). Male tilapia is preferred for aquaculture because of better size and growth rate. The egg membrane was permeabilised by an electric field pulse allowing a minimalized androgen hormone dose of 17alpha-methyltestosterone (MT) (μg l−1 concentration) to achieve monosex sex-male reversal. The technique achieved large-scale inductions of 2000 eggs rather than for individual eggs and was aimed at commercialization (Thailand petty patent no. 13516). The eggs of O. niloticus obtained from our parent breeding stocks were carefully selected to be in the segmentation-pharyngula stage (2–3 dpf - day post fertilization) for electrical inductions in a pulsed-electric field generated between narrow parallel-plate electrodes. The electrodes were powered with an adjustable signal pulse-generator (SPG) developed for on-site operations. The induction medium was prepared using HEPES buffer mixed with a minimized concentration of MT. We experimentally optimized inductions by adjusting the number of square wave pulses, pulse amplitude, pulse durations (period) and a mark-space ratio (pulse width: negative half of period) for the optimum results. A dose of 350 V (electric field intensities of 87.50 kV m−1) of 3 square pulses with 100 μs pulse-period (50:50 mark space ratio) gave the maximum rate of male-sex reversal rate (MSR) of 89.42 ± 2.28 (SD)%, hatching rate (HR) of 93.33 ± 0.58% and survival rate (SR) of 87.49 ± 1.71%, respectively. The off-spring rate (OSR) or sex ratio of the controls were 59.71 ± 3.00% male and 46.33 ± 1.53% female from a hatching rate (HR) of 91.33 ± 1.53% and a survival rate (SR) of 85.08 ± 4.16%, respectively. • Tilapia eggs were permeabilised using electric field induction. • Methyltestosterone (MT) could then penetrate eggs for male sex reversal. • Very large minimalision of amounts of MT used compared to feeding fry with MT. • Male-sex reversal (MSR) 89.4%, hatching rate (HR) 93.3%, survival rate (SR) 87.5%. • A large scale device was developed to treat ≈ 2000 eggs/batch. [ABSTRACT FROM AUTHOR]

A principle diagram of a high-voltage low-power power supply for devices comprising a microchannel plate (MCP) has been developed. A mathematical model was built according to the developed scheme for a detailed study of the operation of the power supply and the selection of the optimal parameters of its components and obtaining the best output voltages. The power supply circuit comprises a control circuit, a pulse transformer, a voltage multiplier circuit, a feedback circuit, and an input stabilizer. The input stabilizer provides the maintenance of the voltage switched in the primary winding of the transformer at a given level regardless of the voltage drop of the power supply primary source. Moreover the stabilizer provides constant voltage maintenance when the load resistance changes. (with Rload changing from 100 to 200 MΩ, Uout did not exceed 3 V).

A generator designed for pulse-frequency power supply of high-voltage technological installations is considered. The generator is connected to an external source with a relatively low constant voltage and power. The generator contains a switch constructed on an IGBT transistor and a transformer as an energy-storage device with a diode "back" connected to the secondary winding and an output capacitor. The operability of the generator model has been experimentally tested, a significant reduction in switching overvoltages and unwanted surges of currents has been obtained, which reduces the likelihood of generator equipment failure. A calculation method has been developed for single-pulse charging of the output capacitor, which makes it possible to determine the resistances, inductances, and capacitances of the generator elements and its voltages, currents, power and efficiency with the active-inductive nature of the load. The calculation method can be used in the design of generators with a power of up to 5 kW and a pulse repetition rate of up to 100 Hz with a pulse energy of up to 50 J. The reliability of the calculation method has been confirmed experimentally. [ABSTRACT FROM AUTHOR]

Gene electrotransfer (GET) is considered one of the most efficient, safe, reproducible, and cost-effective methods of gene therapy, in which a gene is delivered to the cells in the form of a plasmid DNA vector by a method known as electroporation. To achieve successful electroporation, cells must be exposed to sufficiently high electric fields generated by short-duration, high-voltage electrical pulses that result in a temporary increase in plasma membrane permeability. The electrical pulses are generated by pulse generators (electroporators) and delivered to the cells via electrodes (applicators). However, there is a lack of standardized pulse delivery protocols as well as certified clinical pulse generators and applicators for gene delivery. In this paper, the development of a new pulse generator, applicator, and pulse delivery protocol for GET to skin cells is presented. A numerical model of electroporated skin developed and tested for two electrode configurations and two different pulse delivery protocols is also presented. An alternative pulse delivery protocol was proposed. The developed pulse generator, applicator, and the proposed pulse delivery protocol were then used in vivo for GET to skin cells in mice. The results showed high efficiency of the proposed pulse delivery protocol for the purpose of GET in mouse skin cells. Specifically, electroporation with the developed pulse generator, applicator, and proposed pulse delivery protocol resulted in higher gene expression in skin cells compared to the currently used pulse generator, applicator, and pulse delivery protocol. [ABSTRACT FROM AUTHOR]

A 3D electromagnetic circuit design and analysis of a MOSFET-based absorber active integrated antenna has been performed. It integrates a transmitting dual-band double material substrate (DMS) cylindrical surrounding patch antenna (CSPA) with a MOSFET-based absorber of reflected radio frequency power. It is a solution to the problem of performance degradation in the power amplifier (PA) resulting from antenna and PA impedance mismatch. This fully integrated MOSFET-based absorber antenna can absorb reflected RF power with a diode-based quasi-circulator as part of the integrated design circuitry. The antenna used for the proposed integrated design will operate at frequencies ranging from 2 GHz to 3 GHz and from 4.6 GHz to 6.1 GHz, thus providing a bandwidth of 1 GHz and 1.5 GHz at a resonance frequency of 2.5 GHz and 5.3 GHz, respectively. This makes it suitable for use in lower and upper bands of WLAN/WiMAX medium RF front-end applications. Furthermore, the condition for MOSFET connected to the absorber (IS ≤ ID and VDS = 0) has been satisfied at both instances of resonance. In this proposed design, an antenna radiation efficiency of 84% has been observed. [ABSTRACT FROM AUTHOR]

A pulse generator using an avalanche transistor operating in current-mode second breakdown driving a 780 nm laser diode is reported. The laser diode is mounted on the skull of a mouse and used in transcranial infrared light stimulation (TILS) experiments. The output current pulse width is approximately 2 ns in an attempt to generate a true impulse-like optical pulse excitation for the TILS experiments. [ABSTRACT FROM AUTHOR]

BackgroundCell electroporation technology under pulsed electric field has been widely used in water treatment, food sterilization, tissue ablation and other applications. Different electroporation applications have different requirements for the pulse waveform.PurposeThis study aims to propose a new pulse generator structure consisting of a special full bridge (FB) module and multiple half bridge (HB) modules to generate bipolar pulse voltages, stepped waves and combination of narrow and wide pulses can also be realized by only changing the switching sequence.MethodsFirst of all, the structure and working principle of novel circuit were elaborated. Then, a main circuit structure composed of 1 full-bridge module and 4 half-bridge modules composed of 12 switches were designed and implemented. Bipolar pulse voltages, stepped waves and combination of narrow and wide pulses were realized by only changing the switching sequence. Finally, verification of the power supply for cell electroporation experiments was carried out in the potato tuber treatment experiment. [ResultsandConclusions] When each level of capacitor is charged at 220 V, bipolar pulse voltage output with ±2 kV and adjustable pulse width of 1~10 μs is realized. Furthermore, the output of a unipolar 9-level step voltage and a combination of wide and narrow pulses are achieved by controlling the switching sequence. Experiment of potato tuber treatment verified the feasibility of this pulse generator.

Feedforward loops (FFLs) are relatively simple network motifs, made of three interacting genes, that have been found in a large number in E. coli and S. cerevisiae. More recently, they have also been discovered in multicellular eukaryotes. FFLs are evolutionary favored motifs because they enable cells to survive critical environmental conditions. Among the eight types of possible FFLs, the so-called coherent 1 and incoherent 1 FFL are the most abundant. The former carries out a sign-sensitive delay in gene expression; the latter is a pulse generator and a response time accelerator. So far, only few synthetic FFLs have been engineered, either in cell-free systems or in vivo. In this work, we review the main experimental works published on FFLs, with particular focus on novel designs for synthetic FFLs. They are, indeed, quite different from the natural ones that arose during the course of evolution. [ABSTRACT FROM AUTHOR]

In recent years, all-solid-state high-voltage pulse generators have been widely used in irreversible electroporation for tumor ablation technology. However, high voltage may cause the breakdown of loads that leads to short circuits. The short circuit of loads will generate high short-circuit currents that will affect the performance of semiconductor switches. To improve the reliability and lifetime of solid-state pulse generators, a passive synchronous isolated gate drive circuit with short-circuit protection based on decreasing the gate–source voltage is proposed in this article. To verify the overcurrent protection during the breakdown of loads, a solid-state Marx generator prototype using the drive circuit was built and tests were carried out. The experimental results show that the 205-A short-circuit current was clamped with 90 A in less than 500 ns, while the transient voltage can be neglected. Besides, the response time, the maximum transient voltage, and the maximum current amplitude can all be adjusted. [ABSTRACT FROM AUTHOR]

Micro-electrochemical machining (µ-ECM) is a non-conventional machining process used for machining various micro-features on any conducting engineering materials with the required size and shape irrespective of the material's hardness. The present study focused on the machining and characterization of micro-holes machined on a copper plate of 300 µm thickness with a hollow stainless steel tool of outer diameter 250 µm, aqueous sodium nitrate (NaNO3) electrolyte, using the tailor-made µ-ECM experimental setup. The unique feature of the experimental setup is an indigenously made pulse generator circuit and closed-loop tool feed circuit made from a current-based sensor to maintain a constant inter-electrode gap between the tool electrode and the workpiece electrode during the machining process. The input process parameters selected for machining are voltage (V), electrolyte concentration (wt% C), and duty factor (% DF). The effects of these input parameters are studied on output responses like material removal rate, circularity, radial overcut, and taper angle using the grey relational analysis technique. The statistical significance of the input parameters and their interactions on the output responses are also analyzed using the analysis of variance technique. The topography of the machined holes at various experimental conditions is also studied. [ABSTRACT FROM AUTHOR]

Electroporation is a next generation bioelectronics device. The emerging application of electroporation requires high voltage pulses having a pulse-width in the nanosecond range. The essential use of a capacitor results in an increase in the size of the electroporator circuit. This paper discusses the modification of a conventional Marx generator circuit to achieve the high voltage electroporation pulses with a minimal chip size of the circuit. The reduced capacitors are attributed to a reduction in the number of stages used to achieve the required voltage boost. The paper proposes the improved isolation between two capacitors with the usage of optocouplers. Parametric analysis is presented to define the tuneable range of the electroporator circuit. The output voltage of 49.4 V is achieved using the proposed 5-stage MOSFET circuit with an input voltage of 12 V. [ABSTRACT FROM AUTHOR]

Electroporation is an effective technique for genetic manipulation of cells, both in vitro and in vivo. In utero electroporation (IUE) is a special case, which represents a fine application of this technique to genetically modify specific tissues of embryos during prenatal development. Commercially available electroporators are expensive and not fully customizable. We have designed and produced an inexpensive, open-design, and customizable electroporator optimized for safe IUE. We introduce NeuroPorator. We used off-the-shelf electrical parts, a single-board microcontroller, and a cheap data logger to build an open-design electroporator. We included a safety circuit to limit the applied electrical current to protect the embryos. We added full documentation, design files, and assembly instructions. NeuroPorator output is on par with commercially available devices. Furthermore, the adjustable current limiter protects both the embryos and the uterus from overcurrent damage. A built-in data acquisition module provides real-time visualization and recordings of the actual voltage/current pulses applied to each embryo. Function of NeuroPorator has been demonstrated by inducing focal cortical dysplasia in mice. The simple and fully open design enables quick and cheap construction of the device and facilitates further customization. The features of NeuroPorator can accelerate the IUE technique implementation in any laboratory and speed up its learning curve. • NeuroPorator – an open-design electroporator developed for in utero electroporation. • Electroporator with a current-limiting safety circuit to protect the embryos. • Publication with openly shared success rates of in utero electroporation. [ABSTRACT FROM AUTHOR]

We study the possibilities of reducing the location error of acoustic emission (AE) sources for cases where AE sources are located near AE receiving transducers (AET). Artificial neural networks (ANN) were used to reduce the location error and increase the probability of detecting such sources when processing AE diagnostic data. The training of the ANN was carried out according to the parameters of location pulses recorded using a pulse generator on the surface of a steel strip. A broadband transducer installed at various distances from the receiving AET was used to generate pulses. After training, the ANN was used to process the results of locating AE sources recorded during rupture tests of a steel strip with stress raisers in the form of holes with a diameter of 5 mm located at a distance of 40 mm from the receiving AET. The probability of detecting AE sources using the ANN according to the parameters of location pulses in the areas of the stress raisers was , i.e., almost 12 times higher than the probability obtained in the case of using the standard algorithm. [ABSTRACT FROM AUTHOR]

This article presents a comprehensive study on the machining and characterization of the holes machined on a biomaterial Ti-6Al-4V ELI of 350 µm thickness with hollow stainless steel tool electrode of outside diameter 250 µm using the tailor-made µ-ECM experimental setup. The distinct feature of the experimental unit is an indigenously made pulse generator circuit and a closed-loop tool feed circuit made from a current-based sensor to retain a constant inter-electrode gap (IEG) between the tool electrode and the workpiece electrode during the machining operation. The machining process parameters are electrolyte concentration (wt % C), voltage (V) and duty factor (% DF). The output responses of interest are Circularity (C), Material Removal Rate (MRR), Taper Angle (TA), Stray Corrosion Zone (SCZ) Width and Radial Over Cut (ROC) of the hole machined. The maximum MRR obtained is 7.2 µg/s at the parametric combination of 12 V, 15 wt % C and 50% DF. The maximum circularity of 0.989 and minimum SCZ width of 309.796 µm is produced by the combination of 8 V, 15 wt % C and 30% DF. The minimum ROC of 181.091 µm is generated by the combination of 10 V, 20 wt % C and 50% DF. The combination of 12 V, 25 wt % C and 40% DF resulted a minimum TA of 0.235 degrees. The machined hole topography study based on the High Resolution Scanning Electron Microscope (HRSEM) images of all the machined holes revealed that the parametric combination of 8 V, 15 wt % C and 30% DF yielded uniform microstructure in the SCZ no pitting corrosion, smooth and precise hole edge. The presence of sodium and bromine is found in Energy Dispersive Spectroscopy (EDS) analysis of the machined hole surface. In addition to these elements, titanium and vanadium are found in the used tool electrode. [ABSTRACT FROM AUTHOR]

In pulsed electromagnetic field tumor ablation, a bipolar nanosecond pulsed electric field has obvious therapeutic advantages. This article proposes a bipolar linear transformer drive (LTD) source circuit topology with a self-triggering H-bridge for this application. In this topology, in the absence of a magnetic core reset circuit, high-frequency bipolar pulse output is realized by introducing an H-bridge while keeping the circuit structure simple. A self-triggered H-bridge is formed by cleverly introducing a self-triggered circuit in the H-bridge, which reduces the difficulty of circuit control. There are only two main control signals, and the sources of all the main control switches share the same ground. The self-triggered switches are self-triggered through the energy-taking capacitor, which improves the stability of the switch control. Theoretical analysis and simulation results demonstrated the theoretical feasibility of the above-mentioned topology; thus, an experimental prototype was built to test the key parameters. The entire prototype adopts a modular design, and each module consists of only four self-triggering H-bridges and one nanocrystalline magnetic core. The key parameters of the final designed prototype are as follows: voltage amplitude of ±4 kV, pulse width of 60–260 ns, pulse rising edge of approximately 11 ns, continuous operation at a maximum frequency of 10 kHz, and output of 500 kHz high-frequency nanosecond pulse. [ABSTRACT FROM AUTHOR]

This article presents a 200-Gb/s pulse amplitude-modulation four-level (PAM-4) and 100-Gb/s non-return-to-zero (NRZ) transmitter (TX) in 28-nm CMOS technology. To achieve the target data rate, the output bandwidth and swing of the proposed TX are optimized by minimizing the output capacitance of the 4:1 multiplexer (MUX) and driver stage with pull-up current sources and adopting a fully reconfigurable 5-tap feed-forward equalizer (FFE). The key circuit includes a segmented 8:4 MUX and 4:1 MUX/driver, a thermal encoder and retimer, and a flexible clock distribution network. Using the layout generated with Berkeley Analog Generator (BAG), the proposed TX achieves an eye opening with >52.9-mV eye height, 0.36 UI eye width, >98% RLM, and 4.63 pJ/b at 200-Gb/s PAM-4 signaling under >6-dB channel loss at 50 GHz, demonstrating the highest data rate achieved using a planar process. [ABSTRACT FROM AUTHOR]

Ultra-wideband (UWB) technology has been applied in many fields, such as radar and indoor positioning, because of its advantages of having a high transmission rate, anti-multipath interference, and good concealment. In the UWB physical layer, the transmitting link, including an encoder and a pulse generator, is used to improve the anti-interference ability of the signal, while the receiving link, including a receiver and a decoder, can correct the error signal. Therefore, the performance of the UWB physical layer can obviously affect the speed and quality of UWB signal transmission. In this paper, the structure and performance of the codec and transceiver of the UWB physical layer are introduced and compared. In addition, some typical architectures and features are summarized and discussed, which provides a valuable reference and suggestions for the design of the UWB physical layer. Finally, the outlook of the UWB physical layer is presented: its development direction mainly includes high speed, low power consumption, and fewer hardware resources.

A principle diagram of a high-voltage low-power power supply for devices comprising a microchannel plate (MCP) has been developed. A mathematical model was built according to the developed scheme for a detailed study of the operation of the power supply and the selection of the optimal parameters of its components and obtaining the best output voltages. The power supply circuit comprises a control circuit, a pulse transformer, a voltage multiplier circuit, a feedback circuit, and an input stabilizer. The input stabilizer provides the maintenance of the voltage switched in the primary winding of the transformer at a given level regardless of the voltage drop of the power supply primary source. Moreover the stabilizer provides constant voltage maintenance when the load resistance changes. (with Rload changing from 100 to 200 MO, Uout did not exceed 3 V). [ABSTRACT FROM AUTHOR]

The initiation of a shock wave in the gas space of a pulse generator, the exit of this wave from the generator nozzle, and the formation of a nonstationary gas-jet flow downstream of the nozzle exit section were experimentally investigated and numerically simulated as applied to the installations for the gas-pulse cleaning of heat transfer surfaces. An experimental investigation of the structure of a nonstationary underexpanded supersonic gas jet discharging from the generator nozzle into an immersed space and propagating along a side screen modeling a heat transfer surface cleaned was performed on an air stand. The shock-wave and vortex structures of such a jet were numerically investigated in detail by the method used for the simulation of large vortices. [ABSTRACT FROM AUTHOR]