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Feature extraction and fusion are two critical issues for the task of multisource classification. In this article, we propose an enhanced multisource fusion network (EMFNet) to address them in an end-to-end framework. Specifically, two convolutional neural networks are employed to extract features from two different sources. Each network is mainly comprised of three convolutional layers. For each convolutional layer, feature tuning modules are designed to enhance the extracted feature of one source by taking advantage of the other source. After getting the features of two sources, a weighted summation method is used to fuse them. Considering that fusion weights should vary for different inputs, a feature fusion module is designed to achieve this goal. In order to test the performance of our proposed EMFNet, we compare it with state-of-the-art fusion models, including the traditional models and the deep-learning-based models, on two real datasets. Experimental results show that the EMFNet can achieve competitive classification results in comparison with them.

Limited by the current capacity of the discharge switch, the amplitude of the circuit discharge pulse current of electromagnetic pulse welding (EMPW) system is at a relatively low level, which greatly limits the application range of the EMPW technology. In this paper, the trigger vacuum switch (TVS) was selected as the discharge switch, and the double-switch synchronous conduction scheme was proposed. Based on two 20 kV/28 kJ single-switch electromagnetic pulse generation modular, a 20 kV/56 kJ double-switch electromagnetic pulse system was designed, which could generate a pulse current with the amplitude peak value of 360 kA when the charging voltage was 16 kV. Finally, the effective welding of 1 mm Mg/Al alloy plates was realized.

Objective: Unipolar pulses have been used in cell electrofusion over the last decades. However, the problem of high mortality with unipolar pulses has not been solved effectively. The cell fusion rate is restricted by cell mortality. By using the advantages of bipolar pulses which cause less cell damage, this paper attempts to use bipolar pulses to increase the cell fusion rate. Methods : the transmembrane voltage and pore density of cells subjected to unipolar/bipolar pulses were simulated in COMSOL software. In an experiment, two 40 μs unipolar and two 20–20 μs bipolar pulses with electric fields of 2, 2.5, and 3 kV/cm were applied to SP2/0 murine myeloma cells. To determine the cell fusion rate and cell mortality, cells were stained with Hoechst 33342 and propidium iodide. Results: the simulation in this paper showed that a high transmembrane voltage and a high pores density were concentrated only at the contact area of cells when bipolar pulses were used. The results of the cell staining experiment verified the simulation analysis. When bipolar pulses were applied, the cell mortality was significantly reduced. In addition, the cell fusion rate with bipolar pulses was almost two times higher than that with unipolar pulses. Conclusion: for cell electrofusion, compared with unipolar pulses, bipolar pulses can not only reduce the cell mortality remarkably but also improve the cell fusion rate obviously. Significance: this paper introduces a novel way to increase the fusion rate of cells.

Frequency response analysis (FRA) has been widely accepted as a diagnostic tool for power transformer winding deformation faults. Typically, both amplitude-frequency and phase-frequency signatures are obtained by an FRA analyzer. However, most existing FRA analyzers use only the information on amplitude-frequency signature, while phase-frequency information is neglected. It is also found that in some cases, the diagnostic results obtained by FRA amplitude-frequency signatures do not comply with some hard evidence. This paper introduces a winding deformation diagnostic method based on the analysis of binary images obtained from FRA signatures to improve FRA outcomes. The digital image processing technique is used to process the binary image and obtain a diagnostic indicator, to arrive at an outcome for interpreting winding faults with improved accuracy.

High-repetition-rate nanosecond pulses are used widely in many fields, and pulses of different polarities have different effects. A new pulse-generator structure is proposed based on an improved Blumlein pulse-forming line (BPFL) and a transmission-line transformer (TLT). The proposed structure generates pulses with polarity that can be adjusted among positive, negative, and bipolar. A modular design is used for the generator. In each module, three groups of solid-state switches are used to control the BPFL. By adjusting the timing of the control signal, the BPFL can generate high-repetition-rate nanosecond primary pulses with adjustable polarity. These primary pulses are then transmitted to the load through the TLT with amplification and superposition. The pulse-forming process is analyzed theoretically for matched impedance. The strategy for controlling the switches is also illustrated. In addition, the feasibility of the proposed generator is verified by simulations and experiments. Finally, a four-stage prototype is developed that can produce pulses with amplitudes of 0–10 kV, a width of 30 ns, repetition rates up to 200 kHz and adjustable polarity.

Background: There are relatively few studies on the treatment of symptomatic adjacent segment disease(ASD) after anterior cervical discectomy and fusion(ACDF). The purpose of this study to compare the clinical efficacy of zero-profile(zero-p) intervertebral fusion and titanium plate combined with cage fusion for treating ASD after ACDF. Methods: Retrospective analysis was performed on patients who underwent ACDF and readmission due to concurrent symptomatic ASD from October 2014 to June 2019. Among them, 12 cases underwent anterior cervical decompression with zero-p intervertebral fusion (zero-p group), and 14 cases underwent anterior cervical decompression with titanium plate combined with cage fusion (titanium plate group). Operative time, intraoperative blood loss, postoperative Japanese 0rthopaedic Association (JOA) score, visual analogue scale (VAS) scores, neck disability index (NDI), dysphagia Bazaz grade, bone graft fusion Eck grade, C2-C7 Cobb Angle, and related complications were compared between the two groups. Results: The intraoperative blood loss difference between the two groups was not statistically significant (P>0.05). The operation time of the zero-p group was shorter than that of the titanium plate group, with significant differences(P0.05). At the last follow-up, the JOA score, VAS score, NDI index, C2-C7 Cobb Angle were significantly different between the zero-P group and the titanium plate group (P0.05). During the follow-up period, all the patients did not have a rupture of the settler screw and esophageal injury and other related diseases.Conclusions: Both methods can achieve good clinical efficacy in the treatment of symptomatic ASD, and can restore and maintain the physiological curvature of the cervical spine to a certain extent. However, the advantages of zero-p intervertebral fusion including shorter operation time, reducing soft tissue injury, and less postoperative dysphagia.

Background Poor engraftment of intramyocardial stem cells limits their therapeutic efficiency against myocardial infarction ( MI )‐induced cardiac injury. Transglutaminase cross‐linked Gelatin (Col‐Tgel) is a tailorable collagen‐based hydrogel that is becoming an excellent biomaterial scaffold for cellular delivery in vivo. Here, we tested the hypothesis that Col‐Tgel increases retention of intramyocardially‐injected stem cells, and thereby reduces post‐ MI cardiac injury. Methods and Results Adipose‐derived mesenchymal stem cells ( ADSC s) were co‐cultured with Col‐Tgel in a 3‐dimensional system in vitro, and Col‐Tgel encapsulated ADSC s were observed using scanning electron microscopy and confocal microscopy. Vitality, proliferation, and migration of co‐cultured ADSC s were evaluated. In addition, mice were subjected to MI and were intramyocardially injected with ADSC s, Col‐Tgel, or a combination thereof. ADSC s engraftment, survival, cardiac function, and fibrosis were assessed. In vitro MTT and Cell Counting Kit‐8 assays demonstrated that ADSC s survive and proliferate up to 4 weeks in the Col‐Tgel. In addition, MTT and transwell assays showed that ADSC s migrate outside the edge of the Col‐Tgel sphere. Furthermore, when compared with ADSC s alone, Col‐Tgel‐encapsulated ADSC s significantly enhanced the long‐term retention and cardioprotective effect of ADSC s against MI ‐induced cardiac injury. Conclusions In the current study, we successfully established a 3‐dimensional co‐culture system using ADSC s and Col‐Tgel. The Col‐Tgel creates a suitable microenvironment for long‐term retention of ADSC s in an ischemic area, and thereby enhances their cardioprotective effects. Taken together, this study may provide an alternative biomaterial for stem cell‐based therapy to treat ischemic heart diseases.

The Marx circuit structure based on fast high-power semiconductor devices is the classical way of generating picosecond pulses. However, most reported studies suggest that as the number of stages in the Marx circuit increases, the output pulse amplitude tends to saturate. This has of late made high-voltage picosecond-pulse generation a challenge. In this paper, as the number of stages increases, the internal resistance of the avalanche transistor tends to decrease with increasing current flowing through the avalanche transistor. A step-by-step wiring and debugging of the avalanche transistor-based Marx circuit demonstrates this experimentally. That is, for a certain range in the number of stages, saturation of the output pulse amplitude for the Marx circuit of avalanche transistors is not apparent. Introducing a parallel structure for the transistors not only increases the current level of the entire circuit but also further reduces the equivalent resistance of the avalanche transistors, thereby improving the output efficiency. Drawing on microstrip transmission theory, and combining the Marx circuit and avalanche transistor parallel structure, component parameters and circuit topology of the picosecond-pulse generator were redesigned, and a 30-level Marx circuit with a parallel structure of two avalanche transistors was developed. The picosecond-pulse generator outputs a pulse with adjustable voltage amplitude of 0.9–3.1 kV, a 350-ps full-width at half-maximum, a 150-ps rise time, and an adjustable high-stability repetition rate of up to 10 kHz. The number of pulses is precisely controlled. The generator is an all-solid-state compact device with high frequency suitable for research needs.

A picosecond-pulse electric field, matching ultra-wideband antenna, can be applied to biomedical noninvasive therapy. Its effect depends largely on the electric field intensity on the target. Because the amplitude enhancement of a picosecond-pulse source is restricted by many factors, ultra-wideband time-domain antenna research has become important. Here, the intensity of the electromagnetic radiation propagated by the antenna was greatly improved by arraying the antenna feed structure. For targeted focusing, an ellipsoidal reflective surface is commonly utilized, but this structure limits the formation feasibility of the feed structure. Here, the feed structure and the reflector were arrayed at the same time, while satisfying the time and spatial consistency of the electromagnetic waves at the target, the intensity of the electric field at the target was greatly improved, and the size of the focal spot was reduced simultaneously. A Gaussian pulse with a 1-V amplitude and a 200-ps width was used as the excitation source. Using this antenna array, a focal spot less than $1\times 1\times 1$ cm was formed at the target. Also, with the increased number of elements in the antenna array, the electric field intensity of the target increased. The relationship between the field intensity at the target and the number of combined antennas is discussed. The increased field strength eventually levels off, which is also consistent with the theory.

Magnetic pulse compression (MPC) systems are suitable for generating dielectric barrier discharges (DBDs) owing to their capability of producing high-amplitude, short pulse voltage waves. This paper proposes a high-frequency, bipolar magnetic compression system to study DBD plasma characteristics. First, the principle of bipolar MPC is explained [a bipolar MPC system comprises a full bridge inverter circuit, pulse transformer (PT), and magnetic switch (MS)]. Additionally, the design of the PT and MS is described. Then, the waveform of the resistive load is tested and compared with PSpice simulation results. It was found that the nanosecond pulse generator produces a pulse on a resistor with an amplitude of 0–13 kV, a rise time of approximately 100 ns, and a repetition frequency of 0 to several kHz. Finally, this paper studies the plasma characteristics under the application of a high-frequency bipolar pulse, and the charge–voltage Lissajous figure of the discharge waveform is analyzed. Combining discharge photographs and theoretical calculation results yields the relationship between the discharge characteristics and the frequency, which enriches the theoretical study of high-frequency bipolar discharges.

Frequency response analysis (FRA) has recently been developed as a widely accepted tool for power transformer winding mechanical deformation diagnosis, and has proven to be effective and powerful in many cases. However, there still exist problems regarding the application of FRA. FRA is a comparative method in which the measured FRA signature should be compared with its fingerprint. Small differences of FRA signatures in certain frequency bands might be produced by external disturbance, which hinders fault diagnosis. Additionally, the existing correlation coefficient indicator recommended by power industry standards cannot reflect key information of signatures, namely the extreme points. This paper proposes an improved FRA based on binary morphology and extreme point variation. Binary morphology is first introduced to extract the certain frequency bands of signatures with significant difference. A composite indicator of extreme point variation is adopted to realize the diagnosis of fault level. A ternary diagram is constructed by the area proportions of the binary image to identify winding faults, which has a potential to realize cluster analysis of fault types.

For non-invasive treatments in the biomedical field, sub-nanosecond pulse electric field matching ultra-wideband antennas have aroused great interest for their excellent directivity and targeted treatment. Sub-nanosecond pulse generators have proved difficult to control in pulsed power technologies despite many studies of pulse generators based on avalanche transistor theory and the Marx circuit. However, no solution exists to the problems of non-ideal waveform of the output sub-nanosecond pulse and the relatively low effectiveness of the Marx circuit. To resolve these problems, the paper describes a sub-nanosecond pulse generator simulation model based on gradient transmission line theory in PSPICE simulation software and the development of a compact solid-state sub-nanosecond pulse generator (18 cm×18 cm×4 cm). From experimental tests, trigger signals of 5-V amplitude, 5-ns rise and fall times (pulse-width 10 ns-50 ns) were generated by Field-Programmable Gate Array (FPGA). A pulse with 1600-V voltage amplitude, 300-ps full width at half maximum, 150-ps rise time, and 10-kHz high-stability repetition rate was generated in an attenuator load with high-bandwidth (8 GHz, 50 Ω). The effectiveness (Output pulse voltage amplitude / Charge voltage × Stages) of this Marx circuit reached to 41.7%, improving considerably on previous efforts.

Applying high-frequency pulses to animals for tissue ablation can reduce the number and intensity of muscle contractions. Hence, developing a composite pulse generator is necessary to investigate the mechanism of tumor ablation under high-frequency composite pulses. In this study, a high-frequency and high-voltage composite pulse generator is proposed for such application. This generator combines the technology of full-bridge soft-switching circuit, MOSFET series, and RCD equalization circuit. This generator has the capability of producing composite pulses, in which the center frequencies of the bursts are up to 2 MHz, the inter-burst delay is 0.1–10 s, the pulse width is from 100 ns to 100 μs, the pulse amplitude is ±3 kV, and the rise time is around 30 ns. The parameters satisfy the requirements of the experiments for studying muscle contraction under high-frequency pulses and tumor ablation. The details of the generator’s production of high-frequency composite pulses are provided. An all-solid-state modular design makes the generator compact and reliable. Initial experiments are then conducted to verify the performances of the proposed generator.

A bipolar pulse has been proved to be more advanced in the treatment of tumor because of the elimination of muscle contractions and the effect for ablating nonuniform tissue. In this paper, a new type of modular bipolar pulsed-power generator based on Marx generator with double power charging is proposed. The concept of this generator is charging the two series of capacitors in parallel by two power sources, respectively, and then connecting the capacitors in series through solid-state switches with different control strategies. Utilizing a number of fast solid-state switches, the capacitors can be connected in series with different polarities, so that a positive or negative polarity pulse will be delivered to the load. The simulated models of this generator have been investigated in a PSPICE platform, and a laboratory prototype has been implemented in a laboratory. The simulation and test results verify the operation of the proposed topology in different switching modes. The development of this pulse generator can provide the hardware foundation for the research on biological effect without muscle contraction when the tumors are applied with bipolar pulse electric field.

To carry out cell experiments for the pulsed magnetic field treatment of tumor cells, a high $dB/dt$ pulsed magnetic field generator based on a printed circuit board (PCB) Archimedes spiral coil and a self-breakdown air switch is developed. The magnetic field and the induced electric field around the Archimedes spiral coil are calculated. Using COMSOL Multiphysics software, the magnetic field distribution characteristics of the coil are optimally designed. Then, the performance of the generator is measured. Ultimately, the PCB Archimedean spiral coil has seven turns, and it has a diameter of 21 mm. The coil can produce the following pulse magnetic field parameters in a cell culture liquid: an amplitude of 0.92 T, a rise time of 78 ns, a pulsewidth of 1.8 $\mu \text{s}$ , a rate of magnetic field change that reaches $1.1\times 10^{7}$ T/s, a maximum-induced electric field of 55.9 kV/m, a degree of electric field uniformity of 84%, and a maximum-induced current density of $1.7 \times 10^{4}$ A/ $\text{m}^{2}$ . The coil can be used to deliver pulsed magnetic field and induced electric field to biological objects.

The new biological effect of picosecond pulsed electric fields (psPEFs) has elicited the interest of researchers. A pulse generator based on an avalanche transistorized Marx circuit has been proposed. However, the problem of reflection in the transmission of the generated picosecond pulse based on this circuit has not received much attention and remains unresolved. In this paper, a compact picosecond pulse generator based on microstrip transmission theory was developed. A partial matching model based on microstrip transmission line theory was also proposed to eliminate reflection, and a series inductor was utilized to optimize pulse waveform. Through simulation studies and preliminary experimental tests, a pulse optimized with 1015 V amplitude, 620-ps width, and 10-kHz high stability repetition rate was generated. This pulse generator can be used with microelectrodes in cell experiments to explore the biological effect mechanism of psPEF.

Several series and parallel Blumlein-type striplines designed on multilayered printed circuit board (PCB) are connected to match different impedance loads with different pulsewidths to develop a high-voltage nanosecond pulse generator for investigating the biological effects of a nanosecond pulsed electric field. First, the principle of a multistage series–parallel Blumlein stripline system is described. In particular, the multilayered strip transmission line is designed on the five-layered PCB to minimize the volume of the system whose maximum size is 300 mm (length) $\times \,\, 260$ mm (width) $\times \,\, 154$ mm (height), and the gate resistor capacitor and diode active equalizing circuit is used as the dynamic/static balancing tactic. Then, a single-stage Blumlein-type stripline and some multistage series–parallel Blumlein-type stripline are established to test their performance. As a result, the nanosecond pulse generator produces a rectangular pulse on a matched resistor load, with an amplitude of 0–1.7 kV, a pulsewidth of integer multiples of 100 ns, a rise time of $\sim 20$ ns or less, and a repetition frequency of 0 to several kHz. A variety of biomedical loads can be matched by parallel stacking mode, which will facilitate the analysis of the biological effects of the nanosecond pulsed electric field.

This paper combines an unbalanced Blumlein-type multilayered microstrip transmission line with solid-state switches to develop a high-voltage nanosecond pulse generator. This study was performed to emphasize the importance of a compact nanosecond pulse generator for biomedical applications. The unbalanced Blumlein-type transmission line reduces current flow through the solid-state switches. A multilayered microstrip transmission line is stacked onto the four-layered printed circuit board to minimize the system volume. Voltage wave propagation analysis is used to explain the principle of the system, which produced a rectangular pulse. The strategy to produce different pulse widths and the controlled timing of the related solid-state switches is interpreted according to this analysis, highlighting the approach needed to achieve a 50–100 ns pulsewidth. Also, the relevant principle of the variable load impedance of the unbalanced Blumlein-type multilayered microstrip transmission line system is also analyzed. To demonstrate the performance of the generator, a miniaturized system is established. Eventually, the nanosecond pulse generator produces a rectangular pulse on a resistor load of 50 $\Omega $ , with amplitude of 0–2 kV, pulsewidth of 50–100 ns, rise time of approximately 20 ns, and repetition frequency of 0 to several kilohertz. Also, when a 500 $\Omega $ resistor is used instead of a 50 $\Omega $ resistor, the output of the nanosecond pulse voltage is approximately two times that of the applied charging voltage.

National Synchrotron Radiation Laboratory (NSRL) owns the first dedicated synchrotron radiation facility in China, Hefei Light Source (HLS). The HLS was fully upgraded to HLS II in 2016. Following the machine upgrade, the infrared beamline was reconstructed to match the new storage ring and improved its performance. The infrared radiation is extracted from a bending magnet (1 degree port) with an acceptance angle of 65(H) × 55(V) mrad2, which including edge radiation and constant field radiaton. Two endstations were reconstructed. One is for spectroscopy experiment covering from far to near infrared, the other one is for mid-infrared microspectroscopy and imaging experiment. In this paper, we introduce the new infrared beamline and endstations in detail, including optics, experimental techniques developed at two endstations.

Diabetic patients are sensitive to myocardial ischemia-reperfusion (MI/R) injury. During diabetes, branched-chain amino acid (BCAA) catabolism is defective and mitochondrial phosphatase 2C (PP2Cm) expression is reduced. This study aims to elucidate the relationship between PP2Cm downregulation and BCAA catabolism defect in diabetic mice against MI/R injury. PP2Cm was significantly downregulated in hearts of diabetic mice. The cardiac function was improved and the myocardial infarct size and apoptosis were decreased in diabetic mice overexpressing PP2Cm after MI/R. In diabetic mice, the cardiac BCAA and its metabolites branched-chain keto-acids (BCKA) levels, and p-BCKDE1α (E1 subunit of BCKA dehydrogenase)/BCKDE1α ratio were increased while the BCKD activity was decreased. Treatment of diabetic mice subjected to MI/R injury with BT2, a BCKD kinase (BDK) inhibitor, alleviated the BCAA catabolism defect, and improved the cardiac function alongside reduced apoptosis. PP2Cm overexpression alleviated the BCAA catabolism defect and MI/R injury. Similarly, MnTBAP ameliorated the oxidative stress and MI/R injury. BCKA treatment of H9C2 cells under simulated ischemia/reperfusion (SI/R) injury significantly decreased cell viability and increased LDH release and apoptosis. These effects were alleviated by BT2 and MnTBAP treatments. These results suggested that PP2Cm directly mediates the BCAA catabolism defect and oxidative stress observed after MI/R in diabetes. Overexpression of PP2Cm alleviates MI/R injury by reducing the catabolism of BCAA and oxidative stress.

Network Function Virtualization (NFV) is a promising approach for providing efficient and flexible network functions deployment, which also reduces the cost in the network operations compared to traditional method using dedicated hardware. Multiple virtual network functions can be chained together working as service chain to provide a specific service. When multiple network functions share computing resources, how to efficiently schedule them dynamically is a great challenge. In this paper, we first investigate the issue that a single packet drop occurs at different positions of a service chain may have different impact on the performance. In light of this, a packets dropping cost model is carefully defined based on the NF positions in a service chain. Then, according to linear programming, a Minimizing Dropping Cost (MDC) approach is proposed to optimally schedule vNFs. Simulation results show that the proposed algorithm can reduce the total incurred cost by up to 60% compared to the existing common schedule approach.

To reduce the muscle contraction in the treatment process effectively, a bipolar pulse generator needs to be made. A high voltage bipolar nano/microsecond pulse generator combining with Marx and full bridge circuits is proposed in this paper. We choose the solid-state switching devices instead of spark gap switches. The Marx circuits are the core structure to realize energy compression, and the output of nano/microsecond pulse wave can be realized by MOSFET switching. Finally, the bipolar compound pulse can be realized by full bridge circuit structure. In this paper, the structure of main circuit, working process, control strategy of the bipolar nano/microsecond pulse circuit are analyzed. Based on solid-state MOSFET, main circuit of pulse generator is developed. Signal transmission and isolation between high voltage and low voltage are realized through optical fiber and isolated power supply module. Compared with the traditional high-voltage pulse source, our design has more concise circuit structure and better load adaptability. It can achieve the advantages of fast falling edge, higher pulse frequency, pulse width and adjustable voltage amplitude. The generator can operate with load in a larger range with the use of tail-cut switch. In addition, the discharge circuit is added, and the residual charge on the capacitor can be released effectively after the machine has finished working, which can prolong the life length of the instrument. The experimental results show that the system can generate high voltage pulse source amplitude range of 0~6 kV, frequency 0 ~ 1 kHz , pulse width 200 ns ~ 1 μs square wave pulse, low voltage can generate the amplitude range of 0~2 kV, frequency 0 ~ 1 kHz , pulse width 1 μs~ 100 μs square wave pulse.

Background Steep pulse therapy can irreversible electrically brackdown of tumor membrance and cause cell death. In previous studies, we investigated the effect of steep pulsed electroporation on the killing of large cell lung cancer cell line L981- in vitro, and determined the best parameters for killing lung cancer cells by steep pulse technology. But the optimal parameters and the mechanisms of steep pulse irreversible electroporation technology on nude mouse tumor model are unclear. Methods Three settings of steep pulse therapy parameters were applied to the nude mouse model. An in vivo imaging system was employed to observe the effect of different parameters on the mouse model. The pathological changes of the tumor tissue and immunofluorescence data on Caspase-3 protein expression were recorded. Results Under the in vivo imaging system, the steep pulse had an obvious inhibitory effect on the transplanted tumor in the nude mouse model. Pathological tests showed that occurrence of necrosis and apoptosis and expression of Caspase-3 protein in the tumor tissue were increased compared to those in the normal tissue. Conclusions Steep pulse irreversible electroporation technology showed a promising antitumor effect in the nude mouse tumor model. With splint-type electrode, the best treatment parameters determined for the nude mouse tumor model were voltage amplitude 2000 V/cm, pulse width 100 μs, pulse frequency 1 Hz, pulse number 60, and repeat time 3. Moreover, steep pulse induced coagulative necrosis of tumor tissue by cell apoptosis.

Objectives To examine the safety and efficacy of immediate rotational atherectomy (RA) in nondilatable calcified coronary lesions complicated by coronary dissection during percutaneous coronary intervention (PCI). Background In the presence of coronary dissection in nondilatable calcified coronary lesions, conservative management is suggested to permit the dissection to heal prior to treatment with RA. However, many patients have frequent angina attacks and some patients develop serious complications during this period. Methods One hundred and nighty-eight patients with severe coronary calcification underwent PCI, and were randomized into immediate (n = 105) or delayed RA group (n = 93) when coronary dissections occur. The primary endpoint of the present study was all-cause death including cardiac and non-cardiac death in 4 years follow-up. Non-fatal myocardial infarction, stent thrombosis, cardiac tamponade, stroke, target lesion revascularization, New York Heart Association (NYHA) class IV heart failure were analyzed as secondary end points. Results At a follow-up of 4 years, event-free survival rates were not statistically different between the immediate and delayed RA group (81.9% vs 80.6%, P = 0.820). Rates of PCI- and RA-related major adverse cardiac events (MACE) and severe RA-related complications were not statistically different between groups. Luminal loss was not significantly different between the immediate and delayed RA group as evaluated by Intravascular ultrasound (IVUS). Two cases in the delayed RA group experienced myocardial infarction during the 4-week waiting. Conclusion This study indicates that immediate RA during PCI is safe and effective in patients with coronary artery dissection. (J Interven Cardiol 2015;28:456–463)

Seven hundred fifty kilovolt extra-high voltage (EHV) shunt reactors are important power equipment that stabilize the normal operation of an entire 750 kV power grid. Internal winding faults of a reactor could be a difficult issue when the reactor is in service, and result in sudden equipment failure and significant economic losses. To prevent sudden catastrophic failure of equipment, online detection should be implemented to evaluate the state of the reactor properties when requested. In this paper, a noninvasive method based on online impulse frequency analysis was proposed and developed to detect internal winding faults of a 750 kV EHV shunt reactor. Initially, the safe implementation of the online detecting device was verified before field installation. Unlike in previous work, the online detecting device was modified and improved according to the specific situation of shunt reactors. Original fingerprints of 750 kV EHV shunt reactors were obtained and analyzed after site installation and normal operation of the detecting device. A fault simulation test was implemented to validate the method. This paper provides guidance on actual implementation of online impulse frequency response analysis on power equipment.

Power transformers have important roles as voltage converters in substations, which directly affect the safe operation of power grids. Online monitoring of winding deformation, which is one of the most common transformer faults, is crucial in protecting transformers from damage, particularly those induced by short-circuit current failures, and ensuring their safe operation. This study proposes an improved online monitoring method for winding deformations based on the Lissajous graphical analysis of voltage and current. A practical measurement system is also presented and discussed in this paper. A load normalization method is proposed to solve the problem of Lissajous diagrams changing as load varies. Finally, transformer and winding experiments are performed to verify the validity of the proposed load normalization method and the feasibility of the proposed monitoring method in distinguishing winding deformations with different degrees and locations.

Traditionally, microsecond pulsed electric field was widely used in cell electrofusion technology. However, it was difficult to fuse the cells with different sizes. Because the effect of electroporation based on microsecond pulses was greatly influenced by cell sizes. It had been reported that the differences between cell sizes can be ignored when cells were exposed to nanosecond pulses. However, pores induced by those short nanosecond pulses tended to be very small (0.9 nm) and the pores were more easy to recover. In this work, a finite element method was used to simulate the distribution, radius and density of the pores. The innovative idea of "cell electrofusion based on nanosecond/microsecond pulses" was proposed in order to combine the advantages of nanosecond pulses and microsecond pulses. The model consisted of two contact cells with different sizes. Three kinds of pulsed electric fields were made up of two 100-ns, 10-kV/cm pulses; two 10-μs, 1-kV/cm pulses; and a sequence of a 100-ns, 10-kV/cm pulse, followed by a 10-μs, 1-kV/cm pulse. Some obvious advantageous can be found when nanosecond/microsecond pulses were considered. The pore radius was large enough (70nm) and density was high (5×1013m-2) in the cell junction area. Moreover, pores in the non-contact area of the cell membrane were small (1-10 nm) and sparse (109-1012m-2). Areas where the transmembrane voltage was higher than 1V were only concentrated in the cell junction. The transmembrane voltage of other areas were at most 0.6V when we tested the rest of the cell membrane. Cell fusion efficiency can be improved remarkably because electroporation was concentrated in the cell contact area.

This paper analytically investigates the performance of a wireless powered communication system, where a wireless sensor powered by multiple dedicated power beacons (PBs) communicates with a destination. Specifically, we consider a harvest-then-transmit multiple-input and multiple-output (MIMO) communication system, where the locations of the PBs and the interferers are characterized by stochastic geometry tools. In the considered network, both the energy transfer and the information transmission are achieved by adopting MIMO beamforming, and the effect of co-channel interference is taken into account. Under this architecture, we analytically derive the expected energy harvesting rate and an upper bound of the expected transmission rate. Numerical results have shown the impacts of the antenna number, the density of PB and the transmit power of PB on the expected energy harvesting rate and the expected transmission rate.

The design of a spherical coil system for pulsed magnetic field (PMF) exposure is presented for in vivo experiments with tumor-bearing animals. The system has greater focusing capability than conventional systems and has advantages in terms of effectiveness and safety. In the simulation part of the study, the magnetic field distribution of two spherical coil systems were studied using a finite element code, where the influences of coil radius and wire diameter were analyzed to optimize the final design. The simulation results indicate that the coil radius has significant effects on the magnetic field distribution, while the effect of wire diameter is negligible. Based on the designed parameters, a coil system was then developed and the magnetic field focusing ability of the system was measured and evaluated. The coil system has a better focusing performance with the central magnetic induction Bm of 1.3×10-4 T and S80% of 2.8×10-3 m2. The spherical coil system contributes to the system's focusing ability, which is expected to help in experiments for tumor treatment in the near future.

Background To investigate the efficacy and proposed mechanism of bone marrow mononuclear cells (BMMNCs) transplantation for diabetic and non-diabetic patients with ST-segment elevation myocardial infarction (STEMI). Methods One hundred and sixteen patients with STEMI who had successfully undergone percutaneous coronary intervention (PCI) were divided into a diabetic group (n=51) and non-diabetic group (n=65). All of the patients received intracoronary injection of BMMNCs. Results Diabetes down-regulated IGF-1, IGFBP-5, VEGF, SDF-1, IL-6, IL-1α and TNF-α expression and affected the expression of Bmi-1, Gfi1, Tel and Hox-B4 which could prevent premature senescence and maintain the self-renewal capacity of stem cells. Event-free survival rates were not statistically different between the diabetic and non-diabetic group (80% vs. 72.5%, p=0.382). LV ejection fraction (LVEF) and wall motion score index (WMSI) were evaluated by echocardiography and found to be significantly improved in the non-diabetic group compared to the diabetic group over the 4-year follow-up period. Improved myocardial perfusion and reduced infarct size in the non-diabetic group compared to the diabetic group was verified using single-photon emission computed tomographic (SPECT) imaging. The non-diabetic group also had reduced anginal symptoms as assessed by changes in their Seattle Angina Questionnaire scores and Canadian Cardiovascular Society (CCS) Functional Angina classification. An improvement of 6-minute walk distance (6MWD) was also noted to be higher in the non-diabetic group during the follow-up period. Conclusion This study indicates that the beneficial effect of BMMNCs transplantation for STEMI is less pronounced in diabetic patients. The mechanism is associated with decreased BMMNCs function in diabetic patients.

Summary Aims: Angiotensin receptor blockers (ARBs) exert favorable effects on the vascular system, which are not directly related to hypertension lowering function. The no-reflow phenomenon determines the prognosis in patients after acute myocardial infarction (AMI). Early ARB treatment has many beneficial effects on the prognosis after AMI. In this study, we tested the hypothesis that ARB treatment before admission would have beneficial effects on the development of the no-reflow phenomenon after infarction. Methods: We investigated 276 consecutive patients with AMI undergoing successful primary percutaneous coronary intervention (PCI). No-reflow was defined as thrombolysis in myocardial infarction (TIMI) flow grade

In order to keep the original connection of transformer, a novel method and apparatus is proposed for condition monitoring of transformer winding based on the detection of transient overvoltage signals. Firstly, a lumped parameter model of transformer winding is established to verify the equivalence in frequency response analysis between the overvoltage and sweep frequency voltage. Then experimental study is conducted on different types of winding faults, to conform the capability to identify the winding fault types. And the investigation of condition monitoring of 110 kV transformer is conducted. The over-voltage frequency response method is verified and can be applied to online monitoring of field windings.

Pulsed power technology has been used for the ablation tumor. Considerable research shows that a high-strength unipolar pulse electric field can induce irreversible electroporation (IRE) on the cell membrane, which can effectively kill cells. But some scholars and doctors have found that muscle contractions occur during treatment, which are associated with the delivery of electric pulses. Confirmed by further studies that bipolar pulses have been proven more advanced in the treatment of tumor because of the elimination of muscle contractions and the effect for ablating non-uniform tissue. So the bipolar pulse generator is needed for the research on the tumor ablation with bipolar pulses. In this paper, a new type of modular bipolar pulsed-power generator base on Marx generator with double power is proposed. The concept of this generator is charging two series of capacitors in parallel by two power sources respectively, and then connecting the capacitors in series through solid-state switches with different control strategy. Utilizing a number of fast solid-state switches, the capacitors can be connected in series with different polarities, so that a positive or negative polarity pulse will be delivered to the load. A laboratory prototype has been implemented in laboratory. The development of this pulse generator can provide the hardware foundation for the research on biological effect without muscle contraction when the tumors are applied with bipolar pulse electric field.

Magnetic pulse compression (MPC) systems are suitable for generating (Dielectric Barrier Discharges) DBD owing to their capability for producing high amplitude, short pulse voltage waves. Because of the frequency limit caused by magnetic core reset, and by the high DBD discharge voltage, which is often up to several tens kV under the low-frequency unipolar voltage wave, this paper proposes a high frequency, bipolar magnetic compression system to study MPC discharge characteristics. First, the principle of bipolar MPC is explained, which is based on full bridge inverter circuit, pulse transformer, and magnetic switch. Additionally, the design of the pulse transformer and magnetic switch are described. Then, the waveform of the resistive load is tested and compared with PSpice simulation results. It was found that the nanosecond pulse generator produces a pulse on a resistor with an amplitude of 0–13 kV, a rise time of approximately 100ns, a repetition frequency of 0 to several kHz. The preliminary experimental data show the effects of repetition frequency on discharge characteristics. The successful development of the system will facilitate deeply study on bipolar high frequency DBD discharge.

Aims: To determine the effects of percutaneous coronary intervention (PCI) on cardiac perfusion, cardiac function, and quality of life in patients with chronic total occlusion (CTO) lesion in left anterior descending (LAD) coronary artery. Methods and Results: Patients (n=99) with CTO lesion in the LAD coronary artery who had successfully undergone PCI were divided into three groups based on the SPECT/CTCA fusion imaging: (a) no severe cardiac perfusion defects (n=9); (b) reversible cardiac perfusion defects (n=40); or (c) fixed cardiac perfusion defects (n=50). No statistical difference of perfusion abnormality was observed at 6 months and 1 year after PCI in group (a). In group (b), SPECT/CTCA fusion imaging demonstrated that cardiac perfusion abnormality was significantly decreased 6 month and 1 year after PCI. Left ventricular ejection fraction (LVEF) increased significantly at 6 months and 1 year follow up. Quality of life improved at 6 months and 1 year after PCI procedure. Moreover, patients in group (c) also benefited from PCI therapy: a decrease in cardiac perfusion abnormality, an increase in LVEF, and an improvement in quality of life. PCI of coronary arteries in addition to LAD did not significantly affect cardiac function and quality of life improvement in each group. Conclusions: PCI exerts functional and clinical benefits in patients with CTO lesion in LAD coronary artery, particularly in patients with reversible cardiac perfusion defects. SPECT/CTCA fusion imaging may serve as a useful tool to evaluate the outcomes of patients with CTO lesion in LAD coronary artery.

The infrared phonon modes and dielectric constants of bulk and thin film of La2Zr2O7 are studies by infrared spectroscopy. The infrared response of the La2Zr2O7 bulk sample is determined by seven infrared phonon modes. The obtained static dielectric constant is 22.8 and the largest contribution is from the phonon modes at 213.7 and 352.7 cm−1. Compared to the bulk sample, the obtained dielectric constant of the La2Zr2O7 thin film shows an obvious decrease. The loss of the dielectric constant is due to the absence and weakness of some phonon modes in the thin film, even though it still preserves two important modes, mentioned above. The result indicates that the disorder in the La2Zr2O7 thin film has an important influence on the dielectric property.

For the current analytical method of the leakage current on the insulator, the online monitoring system could not be used to accurately judge the contamination severity on the surface of insulators, and a novel method, syntactical pattern recognition, was proposed in this paper. The geometric primitives were extracted by piecewise linearization from the leakage current signals. In accordance with the given grammar, these primitives are constituted into a language recognition unit with the name of finite automaton, where after the finite automaton, the leakage current signals were judged to be the corresponding pattern. The syntactical pattern-recognition module was embed into the “Acqs” software, and a series of experiments for validating this method's performance were made under the following three different conditions: 1) the leakage current of polluted insulators under the different humidity degrees; 2) the leakage current under the different voltage values with moderate humidity; and 3) the polarity effect. The results showed that the structure information of the leakage current could be roundly obtained by the syntactical pattern-recognition method. Consequently, the surface discharge characteristics of insulators could be deeply grasped and the polarity effect of the leakage current of insulators could be accurately and fully recognized.

With the dramatic development of computational science and technology, computer simulation is playing an increasingly important role in scientific research and engineering practice, and is believed to bring about a profound revolution to the mode and means of these activities. For chemical engineering, it will promote the transition from an experience-and-experiment-based research and development mode to the one based on virtual process engineering (VPE). However, such a revolutions till requires tremendous improvements in the Accuracy of physical modeling and numerical methods, the Capability of the computing hardware and software, and the Efficiency of the simulation activities, or in short, ACE. This article will systematically review the 3-decade endeavors at IPE, CAS(Institute of Process Engineering, Chinese Academy of Sciences) on upgrading ACE by establishing a multi-scale computing paradigm focusing on meso-scale structures. We also report recent developments in this direction with projections on future work.

In order to research a new tumor treatment method using exponential decay pulsed magnetic fields (EDPMF), we developed a EDPMF generator by means of the integration of pulsed power technology and modern power electronics technology. After charging a capacitor with a high voltage dc power supply, EDPMF was generated inside the Helmholtz coils by means of discharging the capacitor through a switch to the discharge resistor. After a brief introduction of basic principle of EDPMF generator, steep pulse formation circuit and Helmholtz coils, two main parts of EDPMF generator, were discussed in detail, especially on design techniques. A height-adjustable platform was designed inside the Helmholtz coils. Cell solution and little animals could be treated on this platform. The peak value, width and repeat rate of the output EDPMF waveform could be adjusted independently in the range of 0 - 1 mT, 160 ns-55 μs and 1 Hz-1 kHz, respectively. The rise time of the output EDPMF waveform was shortened to 70-220 ns by means of choosing quickly operating switch and reducing circuit stray inductance. Magnetic field distribution uniformity was improved via designing better geometrical structure of Helmholtz coils. This was proved by finite element simulation and measurement. Cell experiment in vitro was performed by exposing human liver cancer cells (Hep-G2) to pulsed magnetic field (0.8 mT, 55 μs, 15 Hz) using this generator and the result showed that proliferation of cancer cells in treated group was significantly (P

Lightning is a form of pulse power in nature. It is a serious threat to the safe operation of power grid. However, in high voltage power systems, it is almost impossible to directly measure the lightning currents accurately and safely. This paper presents a contactless lightning current sensor for transmission tower based on B-dot probe. This sensor consists of a multi-turn loop, a self-integrating resistance and a shielding. In the laboratory, the typical lightning current (8/20 μs) was simulated by a high impulse current generator. The experiment results show that: the sensor can accurately reproduce the waveform and amplitude of the current generated by the high impulse current generator, based on a specific measuring distance under reasonable design. And this sensor has the advantages of safety, strong anti-interference ability, and good linearity and accuracy.

Objective : The objective is to apply synchrotron-based FTIR microspectroscopy and imaging to human hair tissue and investigate the possibility of the method in gastric cancer research and diagnosis. Methods : Human hair from gastric cancer patients' scalp and normal persons' scalp were studied by synchrotron-based FTIR microspectroscopy and imaging. Results : The micro-spectra and imaging show the difference between the normal and malignant hair tissues. Obvious peak shift of symmetric phosphate band is observed in micro-spectra of medulla region for the hair tissue of gastric cancer patients. Chemical imaging shows the distributions of lipid and amide II/v s PO 2 − have changed in the gastric cancer cases. Conclusions : The study indicates that the hair tissue's infrared microspectroscopy and imaging using synchrotron will be a potentially useful method for rapid early gastric cancer diagnosis.

Aims To evaluate the safety profile and efficacy of bone marrow mononuclear cells (BMMNC) transplantation for ST-segment elevation myocardial infarction (STEMI) by assessing patients and their left ventricular function at up to 4 years follow-up. Methods and results Eighty-six patients with STEMI who had successfully undergone percutaneous coronary intervention (PCI) were randomized to receive intracoronary injection of BMMNC ( n = 41) or saline ( n = 45). Left ventricular ejection fraction, as evaluated by UCG, was markedly improved at 6 months (0.484 ± 0.5 vs. 0.457 ± 0.6, P = 0.001), 1 year (0.482 ± 0.7 vs. 0.446 ± 0.6, P < 0.001), and 4 years (0.505 ± 0.8 vs. 0.464 ± 0.8, P < 0.001) after BMMNC transplant when compared with control group. However, the current cell therapy did not improve the myocardial viability of the infarcted area as assessed by single-photon emission computed tomography analysis at 4 years post-transplant (0.263 ± 0.007 in BMMNC group vs . 0.281 ± 0.008 in control group, P = 0.10). During the follow-up period, one control group case (2.2%) of in-stent restenosis was confirmed by coronary angiography and underwent repeat PCI. Also during follow-up, one death (2.2%) occurred in the control group, and one patient (2.4%) in the BMMNC group had transient acute heart failure. Conclusion This study indicates that intracoronary delivery of autologous BMMNC is safe and feasible for STEMI patients who have undergone PCI, and can lead to long-term improvement in myocardial function.

Compared with the traditional thin film techniques, the matrix-assisted pulsed laser evaporation (MAPLE) technique has many advantages in the deposition of polymer and organic thin films. It has a wide range of applications in many fields, such as non-linear optics, luminescent devices, electronics, various sensors. We have successfully deposited polyimide thin films by using the MAPLE technique. These films were characterized with XPS. The XPS spectra showed that the single-photon effect is obvious at low laser fluence and the chemical bonds will be broken, resulting in decomposition of the films. Contrarily, the single-photon effect will decrease and the multi-photon effect and the photothermal effect will increase at high laser fluence, resulting in the protection of the structure of the polyimide thin films and the obvious decrease in decomposition. High laser fluence is more suitable for the deposition of polymer and organic thin films than low laser fluence.

Primary cultured rat aortic vascular smooth muscle cells (VSMCs) were exposed to different intensities of low-frequency electromagnetic fields (LFEMFs) at 20, 40, and 60 mT for different time periods (10, 20, and 30 minutes). Furthermore, osteopontin (OPN) mRNA and protein expressions were determined by reverse transcription-polymerase chain reaction (RT-PCR) and Western blotting, respectively. Matrix metalloproteinase-2 (MMP-2) activity was measured using gelatin zymography. The results showed that the OPN mRNA and protein expressions and MMP-2 activity of VSMCs were inhibited by exposure to LFEMFs of different intensities in a dose-dependent manner (P < 0.05) but not in a time-dependent manner. In conclusion, exposure to LFEMFs of appropriate intensity for a suitable time period can result in the inhibition of the OPN expression and MMP-2 activity of VSMCs, indicating the potential prophylactic and therapeutic effects of LFEMFs on restenosis (RS) following percutaneous coronary intervention (PCI).