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Partial discharge (PD) is one of the key factors leading to premature insulation failure of film capacitors used in pulse power devices. To study the effect of frequency on the PD characteristics of biaxially oriented polypropylene (BOPP) film, a sphere-plate electrode was used to simulate defects of the air gap between the film layers. PD experiments of the BOPP film were carried out under 1, 10, 100, 500 Hz, and 1 kHz with a rising edge of 65 ns and a pulse width of 300 ns. The results show that the repetitive partial discharge inception voltage (RPDIV), the number of discharges, the rising stage discharge (RSD) amplitude, and the falling stage discharge (FSD) time-lag, all show an increase and then decrease with increasing pulse frequencies and reach a maximum value at a pulse frequency of 100 Hz. Moreover, the FSD discharge amplitude and the RSD discharge time-lag increase with an increasing pulse frequency. From the perspective of initial electron generation, the quantitative mathematical relationship between PD characteristics (RPDIV, PD amplitude, PD number, and PD time-lag) and frequency was established based on the Fowler–Nordheim field emission effect for the first time, which can reflect the influence of frequency on the memory effect and the development process of PD. The results can provide an experimental basis and a mechanistic explanation for the evaluation of PD characteristics for film capacitors under nanosecond pulse voltage. [ABSTRACT FROM AUTHOR]

Pulsed electric field-induced electroporation has been widely used, but its specific perforation theory has not been fully elucidated. Therefore, this Perspective paper takes as a clue the dynamic development relationship between the pore energy and the pore state in cell membranes. First, based on the contribution of line tension, surface tension, steric repulsion, and applied electric field to pore energy, the theoretical models of reversible electroporation of a microsecond pulsed electric field and irreversible electroporation of a high-frequency nanosecond pulsed electric field are reviewed. Then, the contribution of elastic strain energy to pore energy is increased, and the theoretical model of pulsed electric field electroporation considering the mechanical properties of cell membranes is further reviewed. Based on the contribution of magnetic stress generated by the magnetic field and the gradient magnetic field to pore energy, a theoretical model of cell membrane magnetoporation under the action of a pulsed magnetic field is proposed, which lays a theoretical foundation for the popularization and application of non-contact cell membrane perforation technology. [ABSTRACT FROM AUTHOR]

Conductive polymer composites require high conductive filler loadings to achieve relatively ideal electromagnetic interference (EMI) shielding performance, which brings problems such as heavy weight and poor processability and ultimately limits their application in the aerospace field. To solve the above problems and realize the preparation of excellent EMI shielding composites with low filler loadings, a bipolar pulsed electric field-induced graphene nanoplatelets (GNPs) alignment method is proposed in this paper to improve the electrical conductivity and EMI shielding performance. The orientation and alignment of GNPs in the matrix were characterized by x-ray diffraction and scanning electron microscopy, and the results showed that GNPs formed a conductive network. The electrical conductivity of the composite material in the X-band was measured, and the results showed that the bipolar pulsed electric field could significantly improve the electrical conductivity of the composite material; the improvement percentage reached 100%–300% under the five filler loadings. In addition, the EMI shielding effectiveness of the composite material in the X-band was tested. The results showed that the EMI shielding effectiveness of the composite material with a mass fraction of 14% increased from 16.48–15.86 dB to 21.37–20.99 dB with the action of the bipolar pulsed electric field, and the improvement percentage was 32%. This is the first study on improving the EMI shielding performance of composite materials by applying a bipolar pulsed electric field, and it provides an effective method to prepare EMI shielding composites with low filler loadings. [ABSTRACT FROM AUTHOR]

The combination of magnetic fields and magnetic nanoparticles (MNPs) to kill cancer cells by magneto-mechanical force represents a novel therapy, offering advantages such as non-invasiveness, among others. Pulsed magnetic fields (PMFs) hold promise for application in this therapy due to advantages such as easily adjustable parameters; however, they suffer from the drawback of narrow pulse width. In order to fully exploit the potential of PMFs and MNPs in this therapy, while maximizing therapeutic efficacy within the constraints of the narrow pulse width, a feature-matching theory is proposed, encompassing the matching of three aspects: (1) MNP volume and critical volume of Brownian relaxation, (2) relaxation time and pulse width, and (3) MNP shape and the intermittence of PMF. In the theory, a microsecond-PMF generator was developed, and four kinds of MNPs were selected for in vitro cell experiments. The results demonstrate that the killing rate of the experimental group meeting the requirements of the theory is at least 18% higher than the control group. This validates the accuracy of our theory and provides valuable guidance for the further application of PMFs in this therapy. [ABSTRACT FROM AUTHOR]

The mechanical properties of the cell membrane play an important role in electroporation. This paper studied the influence of the mechanical properties of the cell membrane on the transition energy of electroporation through both modeling and experiments. An electromechanical coupling model of a single pore on the cell membrane was established in COMSOL, and the effect of elastic strain energy on the formation of pores was analyzed. Additionally, to compare the transition energy barrier of pores for different elastic properties of the cell membrane, electroporation experiments were carried out at different temperatures. The simulation showed that the elastic strain energy of the cell membrane increased the transition energy barrier of the pores. The experiments also showed that the transition energy barrier was larger when the elasticity of the cell membrane is intact, which was in good agreement quantitatively with the simulation results. We demonstrated that the mechanical properties of the cell membrane hinder the pore formation, which may be due to the increase of the transition energy barrier. We analyzed the possible mechanism of the effect of cell membrane mechanical properties on electroporation and found the contribution of cell membrane mechanical properties to electroporation during the delivery of exogenous substances, which can provide guidance for improving therapies in electrochemotherapy. [ABSTRACT FROM AUTHOR]

Single-domain magnetic particles have unique and excellent magnetic properties and are widely used in biomedical applications, but there are many mechanisms for their response to external magnetic fields. Different models apply under various conditions, which challenges researchers who want to choose a suitable model for their studies. Based on this situation, this paper comprehensively summarizes the mechanisms and models of magnetic loss of single-domain magnetic particles in an external magnetic field. Notably, this paper comprehensively summarizes the non-equilibrium kinetic model of the response of single-domain superparamagnetic particles to external magnetic fields. In this paper, the mechanism for hysteresis loss of single-domain ferromagnetic particles and a model for its calculation are presented, the Stoner–Wohlfarth (SW) model based on equilibrium state and the statistical mechanics model based on non-equilibrium state are introduced; then, the mechanism for the relaxation loss of single-domain superparamagnetic particles and a model for its calculation are introduced, and the linear response model based on equilibrium state and the statistical mechanics model based on non-equilibrium state are introduced in a general way. Lastly, the development of single-domain superparamagnetic particles is briefly prospected. This review provides a convenient reference for researchers to explore the magnetic properties of single-domain magnetic particles and promotes their application and development in the field of biomedicine. [ABSTRACT FROM AUTHOR]

Nanosecond pulsed electric fields over 200 kV/mm have been used for filler alignment in polymer-based thin film (120–250 μm) composites to improve their thermal conductivity, but little research has been performed on bulk composites because of the requirement of an extremely high nanosecond pulsed voltage. In this paper, a microsecond pulsed voltage with a pulse width of 1 μs and an electric field of only 11.76 kV/mm was adopted for the first time to prepare bulk composites of 1.7 mm. The effects of frequency on nanosheets' orientation and the thermal conductivity of epoxy composites were studied. The orientation degree of BN nanosheets was determined based on cross-sectional scanning electron microscopy images and X-ray diffraction peaks. The orientation degree and thermal conductivity of epoxy composites increased with the increase of the frequency, but the increase rate was lower under higher frequencies. The thermal conductivity of composites containing 10 wt. % BN nanosheets prepared under 100 Hz was 0.588 W/mK, which was more than twice that of composites without an applied electric field. Additionally, an effective medium theory model was adopted for thermal conductivity modeling. In addition, thermogravimetric and differential scanning calorimetry analyses were performed to evaluate the thermal properties of the composites. The results showed that after BN orientation in epoxy resin, the composites had higher glass transition temperature and better thermal stability. Microsecond pulsed electric fields are promising for preparing bulk insulation composites with higher thermal conductivity. [ABSTRACT FROM AUTHOR]

RV01 ameliorated MCAO/R-induced neurological dysfunction in mice and OGD/R-induced neuronal damage in SH-SY5Y cells as well as primary neurons. Mechanically, RV01 alleviates acute ischemic stroke injury by promoting mitophagy via targeting CK2α'. [Display omitted] • RV01 ameliorates neurological dysfunction and apoptosis by promoting mitophagy in MCAO/R-induced mice as well as OGD/R-induced SH-SY5Y cells and primary neurons. • Improvement of ischemic stroke by RV01 is blocked by addition of a mitophagy inhibitor. • RV01 alleviates acute ischemic stroke injury by promoting mitophagy via targeting CK2α'. • RV01 targets CK2α' and promotes mitophagy to prevent mitochondrial-dependent release of cytochrome C into the cytoplasm, ROS production, and a decrease in mitochondrial membrane potential as well as ATP, thus attenuating neuronal apoptosis after IS. Ischemic stroke (IS) is a serious threat to human health. The naturally derived small molecule (E)-5-(2-(quinolin-4-yl) ethenyl) benzene-1,3-diol (RV01) is a quinolinyl analog of resveratrol with great potential in the treatment of IS. The aim of this study was to investigate the potential mechanisms and targets for the protective effect of the RV01 on IS. The mouse middle cerebral artery occlusion and reperfusion (MCAO/R) and oxygen-glucose deprivation and reperfusion (OGD/R) models were employed to evaluate the effects of RV01 on ischemic injury and neuroprotection. RV01 was found to significantly increase the survival of SH-SY5Y cells and prevent OGD/R-induced apoptosis in SH-SY5Y cells. Furthermore, RV01 reduced oxidative stress and mitochondrial damage by promoting mitophagy in OGD/R-exposed SH-SY5Y cells. Knockdown of CK2α' abolished the RV01-mediated promotion on mitophagy and alleviation on mitochondrial damage as well as neuronal injury after OGD/R. These results were further confirmed by molecular docking, drug affinity responsive target stability and cellular thermal shift assay analysis. Importantly, in vivo study showed that treatment with the CK2α' inhibitor CX-4945 abolished the RV01-mediated alleviation of cerebral infarct volume, brain edema, cerebral blood flow and neurological deficit in MCAO/R mice. These data suggest that RV01 effectively reduces damage caused by acute ischemic stroke by promoting mitophagy through its interaction with CK2α'. These findings offer valuable insights into the underlying mechanisms through which RV01 exerts its therapeutic effects on IS. [ABSTRACT FROM AUTHOR]

Photocatalysis is one of the most promising green technologies to utilize solar energy for clean energy achievement and environmental governance, such as artificial photosynthesis, water splitting, pollutants degradation, etc. Despite decades of research, the performance of photocatalysis still falls far short of the requirement of 5% solar energy conversion efficiency. Combining photocatalysis with the other physical fields has been proven to be an efficient way around this barrier which can improve the performance of photocatalysis remarkably. This review will focus on the recent advances in photocatalysis coupling by external physical fields, including Thermal-coupled photocatalysis (TCP), Mechanical-coupled photocatalysis (MCP), and Electromagnetism-coupled photocatalysis (ECP). In this paper, coupling mechanisms, materials, and applications of external physical fields are reviewed. Specifically, the promotive effect on photocatalytic activity by the external fields is highlighted. This review will provide a detailed and specific reference for photocatalysis coupling by external physical fields in a deep-going way. [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]

Jinhua Qinggan granules (JHQG), the traditional Chinese formula come into the market in 2016, has been proved clinically effective against coronavirus disease. Acute lung injury (ALI) is a major complication of respiratory infection such as coronavirus and influenza virus, with a high clinical fatality rate. Macrophage activation-induced inflammatory response plays a crucial role in the pathogenesis of ALI. However, the participation of inflammatory response in the efficacy of JHQG and its material basis against ALI is still unknown. The research aims to investigate the inflammatory response-involved efficacy of JHQG on ALI, explore the "ingredient-target-pathway" mechanisms, and searching for key material basis of JHQG by integrated network pharmacology and experimental validation-based approach. Lipopolysaccharide (LPS)-induced ALI mice was established to assess the protective impact of JHQG. Network pharmacology was utilized to identify potential targets of JHQG and investigate its action mechanisms related to inflammatory response in treating ALI. The therapeutic effect and mechanism of the primary active ingredient in JHQG was verified through high performance liquid chromatography (HPLC) and a combination of wet experiments. JHQG remarkably alleviated lung damage in mice model via suppressing macrophage activation, and inhibiting pro-inflammatory mediator level, p-ERK and p-STAT3 expression, TLR4/NF-κB activation. Network pharmacology combined with HPLC found luteolin is the main effective component of JHQG, and it could interact with TLR4/MD2 complex, further exerting the anti-inflammatory property and the protective role against ALI. In summary, our finding clarified the underlying mechanisms and material basis of JHQG therapy for ALI by integrated network pharmacology and experimental validation-based strategy. [Display omitted] [ABSTRACT FROM AUTHOR]

Poor efficacy and low electrical safety are issues in the treatment of tumours with pulsed magnetic fields (PMFs). Based on the cumulative effect of high-frequency pulses and the enhanced perforation effect of targeted nanoparticles, this article proposes for the first time a new method that combines high-frequency nanosecond-pulsed magnetic fields (nsPMFs) with folic acid-superparamagnetic iron oxide nanoparticles (SPIONs-FA) to kill tumour cells. After determining the safe concentration of the targeted iron oxide nanoparticles, CCK-8 reagent was used to detect the changes in cell viability after utilising the combined method. After that, PI macromolecular dyes were used to stain the cells. Then, the state of the cell membrane was observed by scanning electron microscopy, and other methods were applied to study the cell membrane permeability changes after the combined treatment of the cells. It was finally confirmed that the high-frequency PMF can significantly reduce cell viability through the cumulative effect. In addition, the targeted iron oxide nanoparticles can reduce the magnetic field amplitude and the number of pulses required for the high-frequency PMF to kill tumour cells in vitro through magnetoporation. The objective of this research is to improve the electrical safety of the PMF with the use of nsPMFs for the safe, efficient and low-intensity treatment of tumours. [ABSTRACT FROM AUTHOR]

INTRODUCTION Non-combustible nicotine products (NCNPs), such as heated tobacco products (HTPs) and nicotine vaping products (NVPs) have gained a significant nicotine market share in South Korea. This descriptive study examined patterns of regular cigarette and NCNP use among South Korean adults. METHODS Data were from the 2020 International Tobacco Control Korea Survey and included 4016 adults (aged ≥19 years) in the Republic of Korea who were regularly (at least weekly) using at least one NCNP (NVP/HTP, n=2117) and/or smoked cigarettes (n=3763) at the time of the survey. Weighted descriptive estimates were computed to assess respondents' nicotine product use among all respondents (exclusive, dual, or triple use). Thereafter, we identified sociodemographic characteristics associated with NCNP use (n=2117). RESULTS Among Korean adults who were smoking cigarettes, 83.1% (95% CI: 81.6- 84.6) did so exclusively, and 16.9% (95% CI: 15.4-18.4) smoked cigarettes and used NCNPs. Among those who used HTPs (n=1877), 14.9% (95% CI: 11.5-18.4) did so exclusively, 59.6% used HTPs and smoked cigarettes (95% CI: 55.4-63.1), 4.2% used HTPs and vaped (95% CI: 11.5-18.4), and 21.6 % (95% CI: 18.9-24.2) used all three products. Of adults who used HTPs and smoked cigarettes, 86.6% smoked daily. Among those who vaped (n=865), 13.3% did so exclusively (95% CI: 9.4-17.1), 55.6% (95% CI: 49.6-61.5) vaped and smoked cigarettes, 5.1% (95% CI: 1.7-8.6) used HTPs and vaped, and 26.1% (95% CI: 22.1-30.1) used all three products. Of adults who vaped and smoked cigarettes, 82.4% (95% CI: 77.1-87.7) smoked daily. CONCLUSIONS Cigarettes remain the most commonly used nicotine product in South Korea, and among adults using heated tobacco and/or vaping products, the majority were also smoking. Research is urgently needed to assess whether adults who are using an NCNP are doing so to quit, or rather to complement their cigarette smoking. [ABSTRACT FROM AUTHOR]

Tumor-targeted magnetic hyperthermia has recently attracted much attention. Magnetic nanoparticles (NPs) are heat mediator nanoprobes in magnetic hyperthermia for cancer treatment. In this paper, single cubic spinel structural Zn0.3Fe2.7O4 magnetic NPs with sizes of 14 nm–20 nm were synthesized, followed by coating with SiO2 shell. The SLP value of Zn0.3Fe2.7O4/SiO2 NPs below 20 nm changes non-monotonically with the concentration of solution under the alternating current (AC) magnetic field of 430 kHz and 27 kA/m. SLP values of all Zn0.3Fe2.7O4/SiO2 NPs appear a peak value with change of solution concentration. The solution concentrations with optimal SLP value decrease with increasing magnetic core size. This work can give guidance to the better prediction and control of the magnetic hyperthermia performance of materials in clinical applications. [ABSTRACT FROM AUTHOR]

High-intensity nanosecond pulsed electric fields (nsPEFs) are a novel treatment with promising applications for cell stimulation and tissue ablation, and many research studies have shown that gold nanorods (GNRs) are high-conductivity nanomaterials that can enhance electroporation for biomedical applications. In addition, the folic acid (FA) receptor has been demonstrated as a valuable therapeutic target that is highly expressed in a variety of cancers. To reduce the electric field strength required to treat tumors by nsPEFs, for the first time, gold nanorods with folic acid were proposed to achieve higher antimelanoma efficacy at lower electric field intensity in this study. The surface of polyethylene glycol-gold nanorods with good biocompatibility was further modified by folic acid (FA) to provide modified gold nanorods (GNR-PEG-FA) with specific targeted recognition of A375 melanoma cells. The binding of GNRs to A375 melanoma cells was observed by dark field microscopy. After combined treatment with nsPEFs and GNRs, cell viability was evaluated by a CCK-8 assay. Flow cytometry was performed to evaluate apoptosis and the cell cycle. And active caspase 3 was also detected after treatment. The antimelanoma efficacy was enhanced in a pulsed electric field-dependent manner. More importantly, compared with the group of nsPEFs alone and gold nanorods without FA, treating cells with nsPEFs combined with GNR-PEG-FA resulted in a lower percentage of viable cells, higher percentages of necrosis and apoptosis and higher concentration of active caspase 3 and induced cell cycle arrest in S phase, effectively inhibiting the proliferation of A375 melanoma cells. nsPEFs combined with GNR-PEG-FA showed the best antimelanoma efficacy in vitro and effectively killed melanoma cells with low-intensity nsPEFs. The combined treatment of cells with nsPEFs and GNR-PEG-FA is expected to become a safer and more efficient physical treatment of melanomas. [ABSTRACT FROM AUTHOR]

Pharmacokinetic parameters of vitamin K1 have a large range of values in different literature. The aim of this study was to determine the pharmacokinetic parameters of vitamin K1 following post‐constant speed intravenous infusion (PCSII) to provide rational pharmacokinetic parameters of vitamin K1 and compare these with results of noncompartmental analysis following intravenous injection (IV). After 15 hours intravenous infusion of vitamin K1 in rats, the logarithmic concentration–time curve of vitamin K1 was fit to a linear equation following PCSII (R2 = 0.9599 ± 0.0096). Then, half‐time (T1/2), apparent volume of distribution (Vd), and clearance rate (CL) were estimated successively. T1/2 of vitamin K1 was 4.07 ± 0.41 hour, CL was 89.47 ± 3.60 mL/h, and Vd was 525.38 ± 54.45 mL in rats following PCSII. There was no significant difference in pharmacokinetic parameters of vitamin K1 among different sampling times. For noncompartmental analysis, T1/2 and mean residence time (MRTINF) for a sampling duration of 6h were shorter than those of 12 hours or 24 hours sampling duration following IV (P <.05, P <.01). In addition, T1/2 of vitamin K1 was obviously different from MRT‐equated half‐time (T1/2, MRT)(P <.05). Vd and CL of vitamin K1 following PCSII were larger than those following IV based on noncompartmental analysis (P <.01). The results demonstrated that drug distribution in the body was balanced and the Napierian logarithmic concentration–time curve of vitamin K1 fit to a linear equation following PCSII. Vitamin K1 has a long T1/2 and a relatively large Vd following PCSII. [ABSTRACT FROM AUTHOR]

• A new method of estimating the instant case fatality rate of COVID-19 was established. • The average case fatality rate in China was 6.1 ± 2.9%, and it finally stabilized at 5.7% in April, while it was 1% in China except Hubei Province. • The fatality rate of COVID-19 in China was underestimated. The outbreak of coronavirus disease 2019 (COVID-19) in China has been basically controlled. However, the global epidemic of COVID-19 is worsening. We established a method to estimate the instant case fatality rate (CFR) and cure rate of COVID-19 in China. A total of 82 735 confirmed cases released officially by the Chinese authorities from December 8, 2019 to April 18, 2020 were collected. The estimated diagnosis dates of deaths and cured cases were calculated based on the median cure time or median death time of individual cases. Following this, the instant CFR was calculated according to the number of deaths and cured cases on the same estimated diagnosis date. In China, the instant CFR of COVID-19 was 3.8–14.6% from January 1 to January 17; it then declined gradually and stabilized at 5.7% in April. The average CFR in China was 6.1 ± 2.9%, while the CFR was 1.0 ± 0.4% in China except Hubei Province. The cure rate of COVID-19 was 93.9 ± 2.9% in China, and stabilized at 94.3%, while it was 99.0 ± 0.4% in China except Hubei Province. The instant CFR of COVID-19 in China overall was much higher than that in China except Hubei Province. The CFR of COVID-19 in China was underestimated. [ABSTRACT FROM AUTHOR]

Carbon nanotubes (CNTs) with large aspect ratios and excellent electrical properties can enhance the killing effect of nanosecond pulsed electric fields (nsPEFs) on tumor cells, which can improve the electrical safety of nsPEF during tumor treatment. To study the mechanism of the CNT-enhanced killing effect of a nsPEF on tumor cells, a spherical, single-cell, five-layer dielectric model containing randomly distributed CNTs was established using COMSOL and MATLAB, and then, the effects of the addition of CNTs on the electric field and the electroporation effect on the inner and outer membranes were analyzed. The results showed that CNTs can enhance the local electric field strength due to a lightning rod effect, and the closer the CNT tip was to the cell, the greater the electric field strength was around the cell. This increase in the local electric field strength near the cells enhanced the electroporation effects, including pore density, pore area, and pore flux. The simulation results presented in this paper provide theoretical guidance for subsequent development of nsPEF combined with CNTs for use in both cell and tissue experiments. [ABSTRACT FROM AUTHOR]

The saturable reactor insulation epoxy resin is subjected to exponential decay pulse voltage under normal operating conditions. It is of great importance to study the partial discharge (PD) mechanism of epoxy resin under exponential decay pulse and sinusoidal voltages for optimal insulation design. Thus, the difference in the PD behaviours under the exponential decay pulse and sinusoidal voltages is revealed in this study for the first time, and the PD characteristics of the two types of voltages are compared and analysed at 25 and 110°C. Compared to the results for sinusoidal voltage, a higher amplitude, lower repetitive PD inception voltage peak (RPDIV) and fewer PDs are obtained under an exponential decay pulse voltage. Additionally, for the same type of voltage, the RPDIV is lower, the PD magnitude is higher and the number of PDs is smaller at 110°C than those at 25°C. The experimental results can provide a new reference for the insulation redesign of a saturable reactor under an exponential decay pulse voltage. [ABSTRACT FROM AUTHOR]

One of the main challenges in small molecule drug discovery is finding novel chemical compounds with desirable activity. Traditional drug development typically begins with target selection, but the correlation between targets and disease remains to be further investigated, and drugs designed based on targets may not always have the desired drug efficacy. The emergence of machine learning provides a powerful tool to overcome the challenge. Herein, a machine learning‐based strategy is developed for de novo generation of novel compounds with drug efficacy termed DTLS (Deep Transfer Learning‐based Strategy) by using dataset of disease‐direct‐related activity as input. DTLS is applied in two kinds of disease: colorectal cancer (CRC) and Alzheimer's disease (AD). In each case, novel compound is discovered and identified in in vitro and in vivo disease models. Their mechanism of actionis further explored. The experimental results reveal that DTLS can not only realize the generation and identification of novel compounds with drug efficacy but also has the advantage of identifying compounds by focusing on protein targets to facilitate the mechanism study. This work highlights the significant impact of machine learning on the design of novel compounds with drug efficacy, which provides a powerful new approach to drug discovery. [ABSTRACT FROM AUTHOR]

With the change of people's dietary structures, obesity, diabetes, and other related chronic metabolic diseases characterized by energy metabolism disorders have become a public health problem worldwide. Stable isotope-resolved metabolomics (SIRM) as a novel technology to explore energy metabolism will certainly contribute to the development of functional foods to improve energy metabolism disorders. The purpose of this review is to elaborate on the technology processes of SIRM in the research of functional foods with improved energy metabolism disorders, and to promote the applications of this technology in functional food. The research strategies for functional foods for improving energy metabolism disorders were summarized. The progress of the application of SIRM on functional foods was elaborated and policy recommendations were also provided. In conclusion, the precise property of SIRM in revealing metabolic pathways will inevitably facilitate the development of functional foods in improving energy metabolism disorders. [ABSTRACT FROM AUTHOR]

AbstractAn anti-neuroinflammatory activities-guided phytochemical research of Wikstroemia lungtzeensis was performed for the first time. Three undescribed carotane-type sesquiterpenes, excoecafolinols C-E (1–3), and nine known sesquiterpene derivatives were isolated from the effective ethyl acetate extract of W. lungtzeensis. Their structures were determined based on multiple spectroscopic techniques and electronic circular dichroism (ECD) spectra. Furthermore, the anti-neuroinflammatory activities of the identified compounds were evaluated in lipopolysaccharide-stimulated BV-2 cells. Among them, six components (1, 2, 4, 7, 11, 12) exhibited significant inhibitory effects on nitric oxide (NO) production, with IC50 values ranging from 10.48 to 49.41 μM (positive control minocycline, IC50 53.20 μM). Carotane-type sesquiterpenes (1, 2, 4) with high content and significant inhibitory effects, are considered to be major active ingredients of W. lungtzeensis, which might serve as potential therapeutic agents for neurodegenerative diseases. [ABSTRACT FROM AUTHOR]

Objective: To explore role of nucleotide-binding oligomerization domain-like receptor protein 3 (NLRP3) inflammasome in idiopathic membranous nephropathy (IMN) and its possible mechanism of activation. Methods: A total of 135 patients with no adrenal corticosteroid and immunosuppressive therapy who were diagnosed with IMN by renal biopsy were collected, and 10 patients with renal tuberculosis and renal tumors who underwent nephrectomy were selected as control group. Immunohistochemical was used to detect NLRP3, tumor necrosis factor receptor-related factor 6 (TRAF6), Caspase-1, NF-κB p65, MAPK signaling pathway-related proteins, including phosphorylated ERK1/2 (p-ERK1/2), phosphorylated p38 (p-p38), phosphorylated JNK (p-JNK) expressions. Blood and 24-hour urine of IMN patients were collected, and 24-hour urine protein quantification, serum creatinine, creatinine clearance rate, blood urea nitrogen and other general clinical data were were analyzed, correlation between urine protein and NLRP3, Caspase-1, IL-1β, TNF- α, NLRP3 and TRAF6 were analyzed, respectively. Results: Compared with control group, 24-hour urine protein and serum creatinine of IMN patients were significantly increased (both P<0.05), and protein expressions of NLRP3 and Caspase-1 in kidney tissues of IMN patients were significantly increased (both P<0.05), among which renal tissue of stage II IMN patients had the highest protein expressions of NLRP3 and Caspase-1, IL-1β and TNF- α expressions were enhanced (both P<0.05), and IL-1β and TNF-α protein expressions in renal tissue of stage II IMN patients were the strongest, protein expressions of NF-κB p65, p-ERK1/2, p-p38 and p-JNK were significantly increased (all P<0.05) . 24-hour urinary protein of IMN patients was positively correlated with expression of NLRP3 protein in kidney tissues (r=0.689, P<0.01), positively correlated with Caspase-1 protein (r=0.614, P<0.000 1), positively correlated with IL-1β (r=0.708, P<0.000 1), positively correlated with TNF-α (r=0.594, P<0.01) . Conclusion: TRAF6 induces ERK1/2, p38 and JNK signaling pathways to stimulate activation of NLRP3 inflammasome through activation of NF-κB, which promotes occurrence of IMN and production of large amounts of urine protein. [ABSTRACT FROM AUTHOR]

Multivitamins have been widely used for years. Adverse reactions, especially hypersensitivity, to multivitamins are becoming noteworthy. However, the classification of hypersensitivity is confusing, and the trigger is unknown. Multivitamins consist of two vials labelled vial 1 containing Tween‐80 and vial 2. Multivitamins without Tween‐80 were used as a contrast. Behaviouristics, histamine, IgE, and blood pressure of beagle dogs and guinea‐pigs were investigated by observation, ELISA and sphygmomanometer, and degranulation and apoptotic of RBL‐2H3 cells were assayed by spectrophotometry and flow cytometry. The results showed that dogs suffered from multiorgan anaphylactoid symptoms, and dramatically decreased blood pressure, and high plasma concentrations of histamine after the first administration of multivitamins and multivitamins vial 1, which contains Tween‐80, compared to the control, multivitamins vial 2 or multivitamins without Tween‐80. In anaphylaxis assay, guinea‐pigs did not display any anaphylaxis symptoms and there were no changes in plasma histamine and IgE concentrations in the multivitamins and multivitamins vial 1 groups or in the multivitamins vial 2 and multivitamins without Tween‐80 groups except ovalbumin. Compared to the control, the release of β‐hexosaminidase and histamine, and the apoptosis of non‐antigen‐sensitized RBL‐2H3 cells significantly increased in the Tween‐80 and multivitamins and multivitamins vial 1 groups in a concentration‐dependent manner. However, there was no alteration in multivitamins vial 2 and multivitamins without Tween‐80 groups. The results indicate that the hypersensitivity induced by multivitamins may be anaphylactoid reaction, but not anaphylaxis. Multivitamin‐induced release of inflammatory factors is triggered by Tween‐80 through a non‐IgE‐mediated pathway. [ABSTRACT FROM AUTHOR]

The epoxy resin insulation in saturable reactors in a HVDC transmission converter valve is subjected to a bipolar exponential decay pulse voltages under normal operating conditions and its aging mechanism is still unclear. In this paper, an electrothermal aging experiment of epoxy resin was carried out under bipolar exponential decay pulse voltages at high temperature. The dielectric properties of epoxy resin before and after aging were measured using frequency-domain spectroscopy. To quantitatively study the aging characteristics, the double-relaxation Cole-Cole model was used to fit the dielectric spectra. As a result, an exponential function relationship between the relaxation time constant and the aging time of epoxy resin under various aging conditions was obtained. This relationship can be used as an empirical formula to evaluate the degree of aging. Furthermore, a comparison of the aging life characteristics of epoxy resin under pulse and sinusoidal voltages with the same peak value was performed. The results show that the electrothermal aging rate of epoxy resin under a pulse voltage is lower than under a sinusoidal voltage. The effect of the measurement temperature on the insulation life evaluation of epoxy resin was also analyzed. [ABSTRACT FROM AUTHOR]

Aim: Urine cytokeratin 20 (CK20) has been reported as a novel diagnostic biomarker for bladder cancer (BC). This meta‐analysis aims to evaluate the diagnostic value of urine CK20 for BC. Methods: A systematic search for literatures was performed till March 31, 2018. Sensitivity, specificity, positive likelihood ratio (PLR), negative likelihood ratio (NLR), diagnostic odds ratio (DOR) and the area under the summary receiver operator characteristic curve (AUC) were analyzed. Results: Twenty‐seven studies from 22 articles met the eligible criteria. The pooled estimates were as follows: sensitivity, 0.79; specificity, 0.90; PLR, 8.17; NLR, 0.23; DOR, 35.29 and; AUC, 0.90. CK20 was more sensitive for the diagnosis of bladder urothelial carcinoma (BUC) than all types of BC (0.83 vs 0.75). For Tis/Ta tumors, the values were inferior to T1 and ≥T2 stage tumors, that is, the sensitivity (0.74 vs 0.81 vs 0.86), PLR (7.95 vs 9.97 vs 10.75) and DOR (27.81 vs 47.09 vs 69.63). For grade 1 tumors, the values were inferior to grade 2 and ≥grade 3 tumors, that is, the sensitivity (0.70 vs 0.82 vs 0.87), PLR (11.86 vs 13.63 vs 14.26) and DOR (36.63 vs 72.00 vs 101.71). RT‐PCR or PCR showed superior sensitivity and specificity (0.80 vs 0.76, 0.91 vs 0.89) than immunostaining in detection of urine CK20 for BC. Conclusion: Urine CK20 might be a potential noninvasive biomarker for BC, especially for BUC. The diagnostic accuracy of urine CK20 is improved with the progression of tumor stage and grade. In addition, RT‐PCR or PCR shows better diagnostic performance in detecting urine CK20 than immunostaining. [ABSTRACT FROM AUTHOR]

The rise/fall time of a high-voltage nanosecond pulse affects the application effect of the pulse; therefore, it is of great significance to study the adjustment of the rise/fall time. In this paper, a new type of generator topology based on a half-bridge modular multilevel converter (HB-MMC) is proposed that uses MOSFETs as solid-state switches to produce a unipolar/bipolar high-voltage nanosecond pulse with an adjustable rise/fall time. The proposed topology consists of 2 arms, each of which contains several HB-MMC submodules. The capacitors of each arm are charged with a positive voltage and negative voltage in parallel. By controlling the discharging sequence of the two arms, a unipolar or bipolar pulse can be generated. For each arm, by setting the switching sequence of the MOSFETs, the number of capacitors inserted into the discharging circuit can be controlled to allow a multilevel pulse to be generated. The rise/fall time of the output pulse can be adjusted by changing the number of levels and the duration of each level. Detailed illustrations of the proposed configuration and its operational concept are presented. Experimental results for a scaled-down prototype are presented to validate the concept. [ABSTRACT FROM AUTHOR]

This paper considers the electroporation characteristics of a cell under high-frequency nanosecond pulse bursts. A typical two-dimensional cell system, including an organelle membrane, was discretized into nodes using MATLAB, and the mesh transport network method model was established after the bidirectional coupling properties of electrical transport and pore transport were assigned to the nodes within this model. The dynamic process in single-cell electroporation under the application of 10 unipolar high-frequency nanosecond pulse bursts at 1 Hz to the target system was simulated and analyzed. The electroporation characteristics of a single pulse burst and multiple pulse bursts were evaluated. Particularly, the effect of intra-burst frequency on the average pore radius was examined. For the plasma membrane, when multiple pulses were applied, the pore number remained unchanged while the pore radius at the transition region exhibited a more obvious cumulative effect at higher intra-burst frequencies. For the organelle membrane, the number of pores significantly increased when the intra-burst frequency was high (1 MHz). Repetitive pulse bursts expanded the pore radius but do not change the pore number. The results of the present study further enrich our understanding of the electroporation mechanism of a pulsed electric field acting on biological cells. [ABSTRACT FROM AUTHOR]

This paper introduces unipolar high-frequency nanosecond pulse bursts, which combine the advantages of microsecond pulsed electric fields and nanosecond pulsed electric fields, for the treatment of tumors. To take full advantage of this nonthermal pulsed electric field treatment, it is necessary to study the thermal effects of the high-electric-field nanosecond pulse bursts inside tumor tissue. A multiparametric analysis is performed based on a finite-element model of skin with a melanoma tumor that is nipped using the Tweezertrodes. The electric field ranges from 1 to 10 kV/cm, the pulsewidth ranges from 50 to 500 ns, and the frequency in the pulse bursts ranges between 100 kHz and 1 MHz. The total pulselength is $100~\mu \text{s}$ , and the frequency of the pulse bursts is 1 Hz. The Pennes bioheat transfer equation and the Arrhenius equation are used to calculate the temperature and the thermal damage. For pulse parameters of 5 kV/cm, 500 ns, and 1 MHz, the simulated temperature of the skin tumor is only 37.48 °C after 1 s, and the thermal damage is negligible. The temperature and thermal damage to the melanoma tumor in the skin are simulated and calculated for various electric fields, pulse widths, and frequencies. The relationship between the thermal effects on the tumor and the pulse parameters is researched, and pulse parameters for a tumor without thermal damage are ascertained. Temperature measurements of melanoma tumors in nude mice in vivo show that the change in experimental temperature in the tumors is consistent with the simulated average tumor temperature. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Abstract: Regioselective photodimerization of trans‐4‐styrylpyridine (4‐spy) derivatives is performed using pseudorotaxane‐like Zn‐based metal organic frameworks MOFs as templates. The formation of rctt‐HT (head‐to‐tail) dimers is achieved by confining pairs of coordinated 4‐spy derivative ligands within hexagonal windows and then irradiating them with UV light. It is also possible to achieve a photodimerization reaction where two different substituted 4‐spy ligands are included in such a MOF material. The ether bond formation is employed to protect the sensitive ‐OH group of HO‐spy and the methyl group of CH3O‐spy is subsequently removed after the formation of cyclobutane derivative in the CH3O‐spy‐based MOF. Introducing substituents at the 2‐ or 3‐position of the phenyl group of 4‐spy does not significantly affect the rate of the dimerization process except in the case of the strongly electron‐withdrawing nitro group where the rate is significantly decreased. These results are in striking contrast to the mixtures of photoproducts and low yields obtained by untemplated photodimerization in organic solvents. [ABSTRACT FROM AUTHOR]

Regioselective photodimerization of trans‐4‐styrylpyridine (4‐spy) derivatives is performed using pseudorotaxane‐like Zn‐based metal organic frameworks MOFs as templates. The formation of rctt‐HT (head‐to‐tail) dimers is achieved by confining pairs of coordinated 4‐spy derivative ligands within hexagonal windows and then irradiating them with UV light. It is also possible to achieve a photodimerization reaction where two different substituted 4‐spy ligands are included in such a MOF material. The ether bond formation is employed to protect the sensitive ‐OH group of HO‐spy and the methyl group of CH3O‐spy is subsequently removed after the formation of cyclobutane derivative in the CH3O‐spy‐based MOF. Introducing substituents at the 2‐ or 3‐position of the phenyl group of 4‐spy does not significantly affect the rate of the dimerization process except in the case of the strongly electron‐withdrawing nitro group where the rate is significantly decreased. These results are in striking contrast to the mixtures of photoproducts and low yields obtained by untemplated photodimerization in organic solvents. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Five new formyl phloroglucinol meroterpenoids (FPMs), eucalteretials A−E ( 1 – 5 ), along with eight known analogues ( 6 − 13 ), were isolated from the twigs and leaves of Eucalyptus tereticornis . Their structures were established mainly by analysis of comprehensive spectroscopic data, and their absolute configurations were determined by electron circular dichroism (ECD) calculation. Within FPMs, both 1 and 2 are rare adducts of formyl phloroglucinol moiety and germacrene unit with different coupling patterns, respectively. Compound 3 exhibited significant cytotoxicity against HCT116 cell line with an IC 50 value of 4.76 μM. In addition, 5 and 9 were proved to be rare topoisomerase I (Top1) inhibitors. [ABSTRACT FROM AUTHOR]

Nanosecond pulsed electric fields (nsPEFs) with higher repetition frequency presents potential better clinic applicability for tumor treatment. However, the biophysical mechanisms of high-frequency multi-pulse protocols are currently unclear. In this study, a multicellular model with scale of 131 × 121 μm was used to evaluate the accumulation of pore number and pore radius with increasing numbers of pulses. This multicellular system was established based on the transport lattice model combined with the Smoluchowski equation (SE) electroporation model and solved using Pspice and Matlab. The transient and spatial responses of the system under 10 unipolar high-frequency 500 ns pulses with different field intensities (3 kV/cm, 5 kV/cm and 10 kV/cm) and different frequencies (100 kHz, 500 kHz and 1 MHz) were then analyzed. The results show that with increasing numbers of pulses, the pore number remained basically the same but its value was larger when a higher intensity field was applied. The pore evolutions were similar at different field intensities. However, pulse frequency had a significant influence on the changes of pore radius. Pore radius growth effects were more obvious with higher frequency because of its shorter pulse intervals. The results presented here provide theoretical support for mechanism of tumor treatment with high-frequency nanosecond pulses. [ABSTRACT FROM AUTHOR]

Vitamin K1 injection induces severe dose-related anaphylactoid reactions and overdose for the treatment of vitamin K deficiency. We aimed to find an optimal and small dose of vitamin K1 injection to treat vitamin K deficiency and avoid anaphylactoid reactions in animal. Rats were administered a vitamin K-deficient diet and gentamicin to establish vitamin K deficiency model. Behaviour tests were performed in beagle dogs to observe anaphylactoid reactions. The results showed an increased protein induced by vitamin K absence or antagonist II ( PIVKA- II) levels, a prolonging of prothrombin time ( PT) and activated partial thromboplastin time ( APTT) and a decrease in vitamin K-dependent coagulation factor (F) II, VII, IX and X activities in the model group. In vitamin K1 0.01 mg/kg group, the liver vitamin K1 levels increased fivefold and the liver vitamin K2 levels increased to the normal amount. Coagulation markers PT, APTT, FVII and FIX activities returned to normal. Both in the 0.1 and 1.0 mg/kg vitamin K1 groups, coagulation functions completely returned to normal. Moreover, the amount of liver vitamin K1 was 40 (0.1 mg/kg) or 100 (1.0 mg/kg) times as in normal. Vitamin K2 was about 4 (0.1 mg/kg) or 5 (1.0 mg/kg) times as the normal amount. There was no obvious anaphylactoid symptom in dogs with the dose of 0.03 mg/kg, which is equivalent to the dose of 0.01 mg/kg in rats. These results demonstrated that a small dose of vitamin K1 is effective to improve vitamin K deficiency and to prevent anaphylactoid reactions, simultaneously. [ABSTRACT FROM AUTHOR]

The two main components of commercial soybean-based adhesives (SA), polyamidoamine-epichlorohydrin (PAE) resin and soybean protein, are extremely ion-sensitive. When SA is used to bond dyed wood substance and/or mix with anion dyes for labelling wood composites during commercial manufacturing, the regularly used anion dyes in the wood industry may produce significant differences in the bonding capabilities of SA. In the current study, three common tricolor anion dyes in the wood industry were chosen to evaluate their impacts on the structures and properties of soybean protein, PAE resin, and PAE-modified SA, respectively. Analytical data from FTIR, XRD, TGA, NMR, sol-gel test, and plywood evaluation indicated that dye ions had varying effects on the bonding properties of SAs. The addition of chosen red and yellow dyes to SAs enhanced plywood cycling wet strengths by 41.7–42.8%, whereas the blue dye had little impact. The promoter interactions of red- and yellow-dye ions on the unfolding of globular structures of soybean protein, the self-crosslinking of PAE resin, and the sufficient co-crosslinking of soybean protein by PAE resin all contributed to the formation of compact three-dimensional networks of cured SAs. As a result, this work illuminates a novel method for conveniently improving the bonding capabilities of SAs by adding appropriate dyes. • Bonding properties of soybean-based adhesive (SA) affected by dyes were evaluated. • Cycled wet strength of plywood bonded by dye-added SAs improved by 41.7–42.8%. • Effects of dye ions on structures of soybean protein and PAE resin were revealed. • Interactions of dye ions on structures and properties of SA were elucidated. [ABSTRACT FROM AUTHOR]

Ammonia decomposition has attracted significant attention in recent years due to its ability to produce hydrogen without emitting carbon dioxide and the ease of ammonia storage. This paper reviews the recent developments in ammonia decomposition technologies for hydrogen production, focusing on the latest advances in catalytic materials and catalyst design, as well as the research progress in the catalytic reaction mechanism. Additionally, the paper discusses the advantages and disadvantages of each method and the importance of finding non-precious metals to reduce costs and improve efficiency. Overall, this paper provides a valuable reference for further research on ammonia decomposition for hydrogen production. [ABSTRACT FROM AUTHOR]

A high pulse repetition frequency (PRF) nanosecond pulse generator based on Blumlein pulse forming line (BPFL) and transmission line transformer (TLT) is proposed in this paper. The generator combines the BPFL characteristic, which is used to generate a narrow, high PRF pulse, with the excellent performance at high frequency of a transmission line transformer. A modular structure was adopted for this design. The primary pulse produced by the BPFL in each module will output to the load through the TLT amplifier; further, the output of multiple modules can be cascaded to improve the load voltage and output power. Moreover, this reduces the ratio of the output impedance and the input impedance of the TLT, making the generator more suitable for light loads. A microstrip line was used for the transmission line, which makes it possible to match random loads. Additionally, the size of generator was greatly reduced to realize a compact design. MOSFETs were used in the generator to facilitate the control of both the amplitude and PRF of the output. A two-stage laboratory prototype was fabricated to verify the performance of the proposed topology. As a result, the generator produced pulses for matched loads with amplitudes of 0?2.5 kV, pulse width of 20 ns, and repetition frequencies of 0?10 kHz. The generator can be used as a hardware foundation for research on the biomedical effects of exposure to high PRF nanosecond pulse electric fields. [ABSTRACT FROM AUTHOR]

High-frequency nanosecond-pulsed electric fields were recently introduced for tumor or abnormal tissue ablation to solve some problems of conventional electroporation. However, it is necessary to study the thermal effects of high-field-intensity nanosecond pulses inside tissues. The multi-parametric analysis performed here is based on a finite element model of liver tissue with a tumor that has been punctured by a pair of needle electrodes. The pulse voltage used in this study ranges from 1 to 4 kV, the pulse width ranges from 50 to 500 ns, and the repetition frequency is between 100 kHz and 1 MHz. The total pulse length is 100 μs, and the pulse burst repetition frequency is 1 Hz. Blood flow and metabolic heat generation have also been considered. Results indicate that the maximum instantaneous temperature at 100 µs can reach 49 °C, with a maximum instantaneous temperature at 1 s of 40 °C, and will not cause thermal damage during single pulse bursts. By parameter fitting, we can obtain maximum instantaneous temperature at 100 µs and 1 s for any parameter values. However, higher temperatures will be achieved and may cause thermal damage when multiple pulse bursts are applied. These results provide theoretical basis of pulse parameter selection for future experimental researches. [ABSTRACT FROM AUTHOR]

A reconstructed land use/land cover change (LUCC) dataset was used with the Community Earth System Model (CESM) to conduct a climate sensitivity analysis over the past two millennia. Compared to a controlled experiment conducted with the CESM, the LUCC showed significant biogeophysical effects on global climate on multi-decadal to centennial time scales. The global annual mean temperature and precipitation show clear decadal and multi-centennial scale oscillations when the LUCC effect was considered in the CESM simulation. With increased crop acreage and decreased natural vegetation over the past two millennia, the reflected terrestrial solar radiation has increased and the net terrestrial radiation has decreased, leading to a decrease in the global annual mean temperature. Global annual mean precipitation has also decreased along with decreased evaporation and atmospheric humidity. Our simulation suggests that LUCC mainly influences convective precipitation and has little influence on large-scale precipitation. The impact of LUCC has latitudinal and seasonal differences. The largest response of temperature to LUCC has occurred in the middle latitudes of the Northern Hemisphere (NH), while the largest precipitation response occurred at lower latitudes of the NH. The responses of temperature and precipitation to LUCC is stronger in winter and spring than in summer and autumn. [ABSTRACT FROM AUTHOR]

The substitution of environmentally friendly, renewable soybean-based adhesives (SBAs) for formaldehyde-based synthetic resins to produce formaldehyde-free wood composites is of great significance for resource recycling and environmental protection. However, SBA-bonded wood composites often exhibit great variations in bonding properties, due to the diverse interactions of the extractive components in wood. In this study, the extracts of four typical commercial fast-growing timbers were isolated, and their effects on the structures and properties of the SBAs were systematically investigated using FTIR, NMR, TGA, contact angle, buffer capacity, sol–gel test, and plywood evaluation. The analytical data indicated that some of the wood extracts could cause important effects on the bonding properties of the SBAs by impacting the PAE cross-linking capacity and unfolding degree of the globular soybean proteins. Fast-growing hardwood extracts from poplar and eucalyptus timbers containing active groups resulted in increased cross-linking density and improved water resistance of the SBAs. Meanwhile, fast-growing softwood extracts from Chinese fir and Scotch pine containing inert hydrophobic components had slight impacts on PAE cross-linking, but resulted in the agglomeration of unfolded soybean proteins. This formed a weak boundary layer on the wood surface, causing a significant decrease in the water resistance of the SBAs by >35%. These findings presented available analytic approaches of wood extract–SBA interactions and useful guidance for the proper applications of SBAs in the commercial production of wood composites. • The adhesion of soybean adhesive impacted by wood extracts was investigated. • The interactions of the wood extracts with the crosslinker PAE were characterized. • The interactions of wood extracts with soybean proteins were evaluated. • The structure–property changes of the soybean adhesives caused by the wood extracts were revealed. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

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/ \textm^2 . The coil can be used to deliver pulsed magnetic field and induced electric field to biological objects. [ABSTRACT FROM AUTHOR]

Four fluorescent coordination polymers (CPs) [Zn 2 (CH 3 -bpeb) (oba) 2 ] (CP 1), [Zn(2,5-dimethyl-bpeb) 0.5 (oba)] (CP 2), [Zn 4 (F-bpeb) 2 (oba) 4 ] (H 2 O) (CP 3) and [Zn 2 (NH 2 -bpeb) (oba) 2 ] (CP 4) (H 2 oba = 4,4′-oxydibenzoic acid; bpeb = 1,4-bis[(2-(pyridine-4-yl)vinyl)benzene]) were synthesized under solvothermal conditions. The "V" shaped H 2 oba ligand was used for constructing of a ring motif and the linear N-donor ligands (CH 3 -bpeb, 2,5-dimethyl-bpeb, F-bpeb, NH 2 -bpeb) served as interpenetrating columns. CP 1 -CP 4 fluoresced strongly in the solid state and stable suspensions of micron-level particles could be obtained by ultrasound. The fluorescences of these aqueous suspensions of CP 1 -CP 4 were quenched by folic acid (FA) in a concentration-dependent manner. CP test papers could effectively detect FA at micromolar concentrations. The micron-sized CPs suspension was obtained by liquid ultrasonic method and the characteristic fluorescence emission can be quenched by FA in a concentration-dependent manner. [Display omitted] 1. Four fluorescent CPs based on different N-donor ligands were synthesized under solvothermal conditions. 2. The micron-level CPs suspensions were obtained by the liquid ultrasonic method, which showed excellent performance in the detection of FA. 3. CPs can be used as fluorescent test paper, which can be effectively used to visual detection of FA by the naked eye. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM PUBLISHER]

The ultra-low loading amount of Pt nanoparticles on three-dimensional bacterial cellulose derived carbon nanofibers (BCF) was achieved by using a modified atomic layer deposition (ALD) process for hydrogen evolution reaction (HER). The only 5 cycles of ALD led to a high dispersion of Pt nanoparticles on BCF surfaces with an average size of 2 nm, possessing an as low as 0.87 wt% of mass loading. The HER catalytic performance revealed that the as-prepared Pt/BCF have good catalytic activity and stability. The present work provides a general strategy for minimizing the demand of precious-metal catalysts while maintaining their high catalytic efficiency. [ABSTRACT FROM AUTHOR]

Constructing core/shell nanostructures with optimal structure and composition could maximize the solar light utilization. Here, using an Al nanocone array as a substrate, a well-defined regular array of AZO/TiO2 core/shell nanocones with uniformly dispersed Au nanoparticles (AZO/TiO2/Au NCA) is successfully realized through three sequential steps of atomic layer deposition, physical vapor deposition, and annealing processes. By tuning the structural and compositional parameters, the advantages of light trapping and short carrier diffusion from the core/shell nanocone array, as well as the surface plasmon resonance and catalytic effects from the Au nanoparticles can be maximally utilized. Accordingly, a remarkable photoelectrochemical (PEC) performance can be acquired and the photocurrent density of the AZO/TiO2/Au NCA electrode reaches up to 1.1 mA cm−2 at 1.23 V, versus reversible hydrogen electrode (RHE) under simulated sunlight illumination, which is five times that of a flat AZO/TiO2 electrode (0.22 mA cm−2). Moreover, the photoconversion of the AZO/TiO2/Au NCA electrode approaches 0.73% at 0.21 V versus RHE, which is one of the highest values with the lowest applied bias ever reported in Au/TiO2 PEC composites. These results demonstrate a feasible route toward the scalable fabrication of well-modulated core/shell nanostructures and can be easily applied to other metal/semiconductor composites for high-performance PEC. [ABSTRACT FROM AUTHOR]

A characteristic anti-restack 3D BiOCl hierarchitecture constructed by ultrathin BiOCl nanosheets assembled substructures has been designed and synthesized via a facile hydrothermal route. The graphene-like ultrathin BiOCl nanosheets with thickness of about 3.7 nm expose the renowned energetically active (0 0 1) facet, enabling the fast separation and transport of photogenerated electron–hole pairs. Meanwhile, the multi-reflection of light and large surface area of the formed 3D nano-velvet substructures enhance the light harvest and molecule adsorption capability. Consequently, the resultants show a superior photocatalytic performance of 99% photodegradation and corresponding 74% mineralization for rhodamine B within 10 min, and an outstanding photocurrent response under solar light illumination. What is more, the unique microstructure efficiently overcomes the restack of ultrathin nanosheets. This work develops a feasible strategy that utilizes ultrathin nanosheets to design and synthesize anti-restack hierarchitectures for establishing efficacious photocatalytic and water splitting systems. [ABSTRACT FROM AUTHOR]

• The formation of Ni 2 P/MnP 4 heterojunction successfully modulates the local electronic structure of Ni 2 P and enhances the ionization of H and Ni by increasing the electron transfer rate. • The special nanovilli structure and superhydropholic/superaerophobic surface of Ni 2 P/MnP 4 heterojunction accelerates the transference of electrolyte and gaseous products. • A new type Ni 2 P/MnP 4 heterojunction composite material was designed and prepared as bifunctional electrocatalyst at large current density. Producing hydrogen through electrocatalytic overall water splitting with ampere-level current density is still limited by the high cost and poor stability of electrocatalysts. In this work, a new type Ni 2 P/MnP 4 heterojunction composite material was designed and prepared as bifunctional electrocatalyst. Based on XPS spectra and theoretical calculation, the formation of Ni 2 P/MnP 4 heterojunction successfully modulates the local electronic structure of Ni 2 P and enhances the ionization of H and Ni by increasing the electron transfer rate. Moreover, the special nanovilli structure and superhydropholic/superaerophobic surface of Ni 2 P/MnP 4 heterojunction accelerates the transfer of electrolyte and gaseous products. Benefiting from these advantages, the as-prepared Ni 2 P/MnP 4 /CF not only exhibits superior electrocatalytic performance, which can release 10 mA/cm2 current density with a low overpotential of 69 mV and 247 mV for HER and OER respectively, but also shows admirable stability of continuous overall water splitting to drive 1000 mA/cm2 for 180 h without notable activity degradation. We believe this material possesses outstanding potential for industrial applications, and our strategy may provide a new pathway to design relative materials. [ABSTRACT FROM AUTHOR]