On the Interplay Between Force, Temperature, and Electric Fields in the Rupture Process of Mechanophores.

The use of oriented external electric fields (OEEFs) shows promise as an alternative approach to chemical catalysis. The ability to target a specific bond by aligning it with a bond-weakening electric field may be beneficial in mechanochemical reactions, which use mechanical force to selectively rupture bonds. Previous computational studies have focused on a static description of molecules in OEEFs, neglecting to test the influence of thermal oscillations on molecular stability. Here, we performed ab initio molecular dynamics (AIMD) simulations based on density functional theory (DFT) to investigate the behaviour of a model mechanophore under the simultaneous influence of thermal and electric field effects. We show that the change in bond length caused by a strong electric field is largely independent of the temperature, both without and with mechanical stretching forces applied to the molecule. The amplitude of thermal oscillations increases with increasing field strength and temperature, but at low temperatures, the application of mechanical force leads to an additional increase in amplitude. Our research shows that methods for applying mechanical force and OEEFs can be safely combined and included in an AIMD simulation at both low and high temperatures, allowing researchers to computationally investigate mechanochemical reactions in realistic application scenarios.

Electric fields reverse the differentiation of keratinocyte monolayer by down-regulating E-cadherin through PI3K/AKT/Snail pathway.

Re-epithelialization is an important step in skin wound healing, referring to the migration, proliferation, and differentiation of keratinocytes around the wound. During this process, the edges of the wound begin to form new epithelial cells, which migrate from the periphery of the wound towards the center, gradually covering the entire wound area. These newly formed epithelial cells proliferate and differentiate, ultimately forming a protective layer over the exposed dermal surface. Wound endogenous electric fields (EFs) are known as the dominant factor to facilitate the epidermal migration to wound center. However, the precise mechanisms by which EFs promote epidermal migration remains elusive. Here, we found that in a model of cultured keratinocyte monolayer in vitro, EFs application reversed the differentiation of cells, as indicated by the reduction of the early differentiation markers K1 and K10. Genetic manipulation confirmed that EFs reversed keratinocyte differentiation through down-regulating the E-cadherin-mediated adhesion. By RNA-sequencing analysis, we screened out Snail as the transcription suppressor of E-cadherin. Snail knockdown abolished the down-regulation of E-cadherin and the reversal of differentiation induced by EFs. KEGG analysis identified PI3K/AKT signaling for Snail induction under EFs. Inhibition of PI3K by LY294002 diminished the EFs-induced AKT activation and Snail augmentation, largely restoring the level of E-cadherin reduced by EFs. Finally, in model of full-thickness skin wounds in pigs, we found that weakening of the wound endogenous EFs by the direction-reversed exogenous EFs resulted in an up-regulation of E-cadherin and earlier differentiation in newly formed epidermis in vivo. Our research suggests that electric fields (EFs) decrease E-cadherin expression by suppressing the PI3K/AKT/Snail pathway, thereby reversing the differentiation of keratinocytes. This discovery provides us with new insights into the role of electric fields in wound healing. EFs intervene in intracellular signaling pathways, inhibiting the expression of E-cadherin, which results in a lower differentiation state of keratinocytes. In this state, keratinocytes exhibit increased migratory capacity, facilitating the migration of epidermal cells and wound reepithelialization.

Enhancing protein extraction from heterotrophic Auxenochlorella protothecoides microalgae through emerging cell disruption technologies combined with incubation.

This study evaluated pulsed electric fields (PEF) and ultrasonication (US) combined with incubation to enhance cell disruption and protein extraction from Auxenochlorella protothecoides, comparing them to conventional high-pressure homogenization (HPH). A 5 h incubation enhanced protein yield by 79.4 % for PEF- and 27.2 % for US-treated samples. Extending the incubation to 24 h resulted in a total yield increase of 122 % for PEF (0.25 ± 0.03 kgEP kgTP-1) and 51.9 % for US (0.20 ± 0.02 kgEP-1 kgTP-1). Autofermentation in untreated cells after 24 h resulted in protein release with lower yields than all other treated and incubated samples. While HPH had the highest protein yield (0.58 ± 0.04 kgEP kgTP-1), PEF-incubation after 5 h (56.6 ± 5.3 MJ kgEP-1) and 24 h (49.5 ± 3.7 MJ kgEP-1) were 1.5 and 1.7-times more energy-efficient than HPH (82.9 ± 7.8 MJ kgEP-1). PEF combined incubation is an energy-efficient and targeted protein extraction method in heterotrophic A. protothecoides biorefinery.

Enhancing the Electrochemical Activity of 2D Materials Edges through Oriented Electric Fields.

The edges of 2D materials have emerged as promising electrochemical catalyst systems, yet their performance still lags behind that of noble metals. Here, we demonstrate the potential of oriented electric fields (OEFs) to enhance the electrochemical activity of 2D materials edges. By atomically engineering the edge of a fluorographene/graphene/MoS2 heterojunction nanoribbon, strong and localized OEFs were realized as confirmed by simulations and spatially resolved spectroscopy. The observed fringing OEF results in an enhancement of the heterogeneous charge transfer rate between the edge and the electrolyte by 2 orders of magnitude according to impedance spectroscopy. Ab initio calculations indicate a field-induced decrease in the reactant adsorption energy as the origin of this improvement. We apply the OEF-enhanced edge reactivity to hydrogen evolution reactions (HER) and observe a significantly enhanced electrochemical performance, as evidenced by a 30% decrease in Tafel slope and a 3-fold enhanced turnover frequency. Our findings demonstrate the potential of OEFs for tailoring the catalytic properties of 2D material edges toward future complex reactions.

Bronchial Rheoplasty for Chronic Bronchitis: Results from a Canadian Feasibility Study with RheOx®.

Purpose: Chronic bronchitis (CB), a chronic obstructive pulmonary disease (COPD) phenotype defined by persistent mucus hypersecretion and cough, is associated with poor quality of life, exacerbations, and lung function impairment. Bronchial Rheoplasty (BR) delivers non-thermal pulsed electric fields to airway epithelium and submucosa. Preliminary studies demonstrated reduced airway goblet cell hyperplasia and symptom improvement in response to BR. This study aimed to further assess the safety and clinical feasibility of BR in the setting of CB. Patients and Methods: This 3-center, single-arm study evaluated the safety and feasibility of BR in Canadian patients. The major inclusion criteria were the sum of CAT first 2 questions (cough and mucus) ≥ 7 out of 10 and FEV1 ≥ 30% predicted. Right-sided airways were treated first; left, 1 month later. Serious adverse events (SAEs) were tabulated through 12 months. Outcomes were evaluated using the SGRQ and CAT. Results: Ten patients with CB were enrolled and followed for 12 months. The BR procedure was successful in all patients (mean age 69 ± 5.8 years, post-BD FEV1 77.1 ± 28.3, SGRQ 56.2 ± 8.8, CAT 25.4 ± 4.7). Only one SAE, a COPD exacerbation 13 days following the BR procedure, was considered device related. No additional SAEs occurred through 12 months, and 90% of the patients were CAT responders (≥ 2-point improvement) at 3 and 6 months. Similar results were observed in SGRQ. Conclusion: BR was safe and well-tolerated. Meaningful symptom improvement was observed through 12 months, suggesting BR may be a viable treatment option for patients with CB.

Electrostatic pollination by butterflies and moths.

Animals, most notably insects, generally seem to accumulate electrostatic charge in nature. These electrostatic charges will exert forces on other charges in these animals' environments and therefore have the potential to attract or repel other objects, for example, pollen from flowers. Here, we show that butterflies and moths (Lepidoptera) accumulate electrostatic charge while in flight. Then, using finite element analysis, we demonstrate that when within millimetres of a flower, the electrostatic charge of a lepidopteran generates an electric field in excess of 5 kV m-1, and that an electric field of this magnitude is sufficient to elicit contactless pollen transfer from flowers across air gaps onto the body of a butterfly or moth. Furthermore, we see that phylogenetic variations exist in the magnitude and polarity of net charge between different species and families and Lepidoptera. These phylogenetic variations in electrostatic charging correlate with morphological, biogeographical and ecological differences between different clades. Such correlations with biogeographical and ecological differences may reflect evolutionary adaptations towards maximizing or minimizing charge accumulation, in relation to pollination, predation and parasitism, and thus we introduce the idea that electrostatic charging may be a trait upon which evolution can act.

Boosting electrocatalytic ammonia synthesis from nitrate by asymmetric chemical potential activated interfacial electric fields.

The electrocatalytic nitrate reduction reaction (NO3- RR) has immense potential to alleviate the problem of groundwater pollution and may also become a key route for the environmentally benign production of ammonia (NH3) products. Here, the unique effects of interfacial electric fields arising from asymmetric chemical potentials and local defects were integrated into the binary Bi2S3-Bi2O3 sublattices for enhancing electrocatalytic nitrate reduction reactions. The obtained binary system showed a superior Faraday efficiency (FE) for ammonia production of 94 % and an NH3 yield rate of 89.83 mg gcat-1h-1 at -0.4 V vs. RHE. Systematic experimental and computational results confirmed that the concerted interplay between interfacial electric fields and local defects not only promoted the accumulation and adsorption of NO3-, but also contributed to the destabilization of *NO and the subsequent deoxygenation hydrogenation reaction. This work will stimulate future designs of heterostructured catalysts for efficient electrocatalytic nitrate reduction reactions.

Tumor-treating fields in cancer therapy: advances of cellular and molecular mechanisms.

Tumor-Treating Fields (TTFields) use intermediate-frequency and low-intensity electric fields to inhibit tumor cells. However, their mechanisms are still not well understood. This article reviews their key antitumor mechanisms at the cellular and molecular levels, including inhibition of proliferation, induction of death, disturbance of migration, and activation of the immune system. The multifaceted biological effects in combination with other cancer treatments are also summarized. The deep insight into their mechanism will help develop more potential antitumor treatments.

Design and fabrication of 3D-printed in situ crystallization plates for probing microcrystals in an external electric field.

X-ray crystallography is an established tool to probe the structure of macromolecules with atomic resolution. Compared with alternative techniques such as single-particle cryo-electron microscopy and micro-electron diffraction, X-ray crystallography is uniquely suited to room-temperature studies and for obtaining a detailed picture of macromolecules subjected to an external electric field (EEF). The impact of an EEF on proteins has been extensively explored through single-crystal X-ray crystallography, which works well with larger high-quality protein crystals. This article introduces a novel design for a 3D-printed in situ crystallization plate that serves a dual purpose: fostering crystal growth and allowing the concurrent examination of the effects of an EEF on crystals of varying sizes. The plate's compatibility with established X-ray crystallography techniques is evaluated.

Preparation of PANI/CuPc/PDMS Composite Elastomer with High Dielectric Constant and Low Modulus Assisted by Electric Fields.

Dielectric elastomer is a kind of electronic electroactive polymer, which plays an important role in the application of soft robots and flexible electronics. In this study, an all-organic polyaniline/copper phthalocyanine/silicone rubber (PANI/CuPc/PDMS) dielectric composite with superior comprehensive properties was prepared by manipulating the arrangement of filler in a polymer matrix assisted by electric fields. Both CuPc particles and PANI particles can form network structures in the PDMS matrix by self-assembly under electric fields, which can enhance the dielectric properties of the composites at low filler content. The dielectric constant of the assembled PANI/CuPc/PDMS composites can reach up to 140 at 100 Hz when the content of CuPc and PANI particles is 4 wt% and 2.5 wt%, respectively. Moreover, the elastic modulus of the composites remains below 2 MPa, which is important for electro-deforming. The strain of assembled PANI/CuPc/PDMS three-phase composites at low electric field strength (2 kV/mm) can increase up to five times the composites with randomly dispersed particles, which makes this composite have potential application in the field of soft robots and flexible electronics.

Comparative analysis of non-invasive and invasive alternating electric fields therapy for malignant gliomas: a simulation study.

Alternating electric fields (AEFs) at intermediate frequencies (100-300 kHz) and low intensities (1-3 V/cm) have shown promise as an effective approach for inhibiting cancer cell proliferation. However, a noticeable research gap exists in comparing the biophysical properties of invasive and non-invasive AEFs methods, and AEFs delivery strategies require further improvement. In this study, we constructed a realistic head model to simulate the effects of non-invasive and invasive AEFs on malignant gliomas. Additionally, a novel method was proposed involving the placement of a return electrode under the scalp. We simulated the electric field and temperature distributions in the brain tissue for each method. Our results underscore the advantages of invasive AEFs, showcasing their superior tumor-targeting abilities and reduced energy requirements. The analysis of brain tissue temperature changes reveals that non-invasive AEFs primarily generate heat at the scalp level, whereas invasive methods localize heat production within the tumor itself, thereby preserving surrounding healthy brain tissue. Our proposed invasive AEFs method also shows potential for selective electric field intervention. In conclusion, invasive AEFs demonstrate potential for precise and effective tumor treatment. Its enhanced targeting capabilities and limited impact on healthy tissue make it a promising avenue for further research in the realm of cancer treatment.

Tuning Charge-Transfer States by Interface Electric Fields.

Intermolecular charge-transfer (CT) states are extended excitons with a charge separation on the nanometer scale. Through absorption and emission processes, they couple to the ground state. This property is employed both in light-emitting and light-absorbing devices. Their conception often relies on donor-acceptor (D-A) interfaces, so-called type-II heterojunctions, which usually generate significant electric fields. Several recent studies claim that these fields alter the energetic configuration of the CT states at the interface, an idea holding prospects like multicolor emission from a single emissive interface or shifting the absorption characteristics of a photodetector. Here, we test this hypothesis and contribute to the discussion by presenting a new model system. Through the fabrication of planar organic p-(i-)n junctions, we generate an ensemble of oriented CT states that allows the systematic assessment of electric field impacts. By increasing the thickness of the intrinsic layer at the D-A interface from 0 to 20 nm and by applying external voltages up to 6 V, we realize two different scenarios that controllably tune the intrinsic and extrinsic electric interface fields. By this, we obtain significant shifts of the CT-state peak emission of about 0.5 eV (170 nm from red to green color) from the same D-A material combination. This effect can be explained in a classical electrostatic picture, as the interface electric field alters the potential energy of the electric CT-state dipole. This study illustrates that CT-state energies can be tuned significantly if their electric dipoles are aligned to the interface electric field.

Pulsed Electric Field Technology for the Extraction of Glutathione from Saccharomyces cerevisiae.

Glutathione is a potent antioxidant that has shown promise in enhancing the processing of various foods and drinks such as bread and wine. Saccharomyces cerevisiae stands as a primary microorganism for glutathione production. This study sought to assess the potential of pulsed electric fields (PEFs) in extracting glutathione from S. cerevisiae cells. Yeast cells were subjected to PEF treatment (12 kV/cm, 150 µs) followed by incubation at varying pH values (4.0, 6.0, and 8.0) and temperatures (4 °C and 25 °C). Glutathione and protein extraction were assessed at different incubation times. Within one hour of incubation, PEF-treated yeast cells released over 60% of their total glutathione content, irrespective of pH and temperature. Notably, the antioxidant activity of the resulting extract surpassed that obtained through complete mechanical cell destruction and hot water, which form the conventional industrial extraction method in the glutathione industry. These results suggest that PEF could offer a rapid and more selective procedure, improving the extraction of this bioactive compound.

Effects of Weak Electric Fields on the Denitrification Performance of Pseudomonas stutzeri: Insights into Enzymes and Metabolic Pathways.

Enhanced denitrification has been reported under weak electric fields. However, it is difficult to investigate the mechanism of enhanced denitrification due to the complex interspecific interactions of mixed-culture systems. In this study, Pseudomonas stutzeri, capable of denitrification under anaerobic conditions, was selected for treating low COD/N (2.0, ratio between concentration of chemical oxygen demand and NO3--N) artificial wastewater under constant external voltages of 0.2, 0.4, and 0.6 V. The results revealed that P. stutzeri exhibited the highest efficiency in nitrate reduction at 0.2 V. Moreover, the maximum nitrate removal rate was 15.96 mg/(L·h) among the closed-circuit groups, 19.39% higher than that under the open-circuit group. Additionally, a notable reduction in nitrite accumulation was observed under weak electric fields. Enzyme activity analysis showed that the nitrate reductase activities were significantly increased among the closed-circuit groups, while nitrite reductase activities were inhibited. Transcriptomic analysis indicated that amino acid metabolism, carbohydrate metabolism, and energy metabolism were increased, enhancing the resistance of P. stutzeri to environmental stress and the efficiency of carbon source utilization for denitrification. The current study examined the impacts of weak electric fields on enzyme activities and microbial metabolic pathways and offers valuable insights into the mechanism by which denitrification is enhanced by weak electric fields.

Dry Reforming of Methane on Ni/LaZrO2 Catalyst under External Electric Fields: A Combined First-Principles and Microkinetic Modeling Study.

Dry reforming of methane (DRM) reaction has great potential in reducing the greenhouse effect and solving energy problems. Herein, the DRM reaction mechanism and activity on Ni16/LaZrO2 catalyst under electric fields were comprehensively investigated by combining density functional theory calculations with microkinetic modeling. The results showed that La doping increases the interaction between Ni and ZrO2 by Ni cluster transfer of more electrons. The adsorption strength of species followed the order Ni16/ZrO2 > Ni16/LaZrO2, which is consistent with the results for the d-band center but opposite to the metal-support interaction. The best DRM reaction path on Ni16/LaZrO2 was the CH2-O pathway, which is different from the CH-O pathway on Ni(111) and Ni16/ZrO2. Both positive and negative electric fields of strong and weak metal-support interactions reduced the energy barrier of DRM reaction. Importantly, our results showed that the more dispersed and smaller Ni12/LaZrO2 model by considering the dispersing effect induced by La doping, which displayed very different results from that of Ni16/LaZrO2: reduced the energy barrier for methane decomposition, thereby promoting DRM reaction activity. Microkinetic results showed that the carbon deposition behavior of DRM becomes weaker on Ni16/LaZrO2 due to the suppression of methane decomposition in the presence of La doping compared to Ni16/ZrO2, but the opposite result is obtained on Ni12/LaZrO2. The order of DRM reactivity was Ni16/LaZrO2 < Ni16/ZrO2 < Ni12/LaZrO2, which is consistent with the experiment observations. The conversion of methane and CO2 was higher in positive electric fields than in negative electric fields at low temperatures, but the results were opposite at high temperature. Negative electric fields can improve the carbon deposition resistance of Ni-based catalysts compared to positive electric fields. The degree of rate control analysis showed that CHx* oxidation also plays an important role in the DRM reaction. We envision that this study could provide a deeper understanding for guiding the widespread application of electric field catalysis.

Effect of Pulsed Electric Fields on the Shelf Stability and Sensory Acceptability of Osmotically Dehydrated Spinach: A Mathematical Modeling Approach.

This study focused on the osmotic dehydration (OD) of ready-to-eat spinach leaves combined with the pulsed electric field (PEF) pre-treatment. Untreated and PEF-treated (0.6 kV/cm, 0-200 pulses) spinach leaves were osmotically dehydrated at room temperature for up to 120 min. The application of PEF (0.6 kV/20 pulses) prior to OD (60% glycerol, 25 °C, 60 min) lowered water activity (aw = 0.891) while achieving satisfactory product acceptability (total sensory hedonic scoring of 8). During the storage of the product (at 4, 8, 12, and 20 °C for up to 30 d), a significant reduction in total microbial count evolution was observed (9.7 logCFU/g for the untreated samples vs. 5.1 logCFU/g for the PEF-OD-treated samples after 13 d of storage at 4 °C). The selection of these PEF and OD treatment conditions enabled the extension of the product shelf life by up to 33 d under chilled storage. Osmotically treated spinach could find application in ready-to-eat salad products with an extended shelf life, which is currently not possible due to the high perishability of the specific plant tissue.

Advanced tumor electric fields therapy: A review of innovative research and development and prospect of application in glioblastoma.

BACKGROUND: Glioblastoma multiforme (GBM) is an aggressive malignant tumor with a high mortality rate and is the most prevalent primary intracranial tumor that remains incurable. The current standard treatment, which involves surgery along with concurrent radiotherapy and chemotherapy, only yields a survival time of 14-16 months. However, the introduction of tumor electric fields therapy (TEFT) has provided a glimmer of hope for patients with newly diagnosed and recurrent GBM, as it has been shown to extend the median survival time to 20 months. The combination of TEFT and other advanced therapies is a promising trend in the field of GBM, facilitated by advancements in medical technology. AIMS: In this review, we provide a concise overview of the mechanism and efficacy of TEFT. In addition, we mainly discussed the innovation of TEFT and our proposed blueprint for TEFT implementation. CONCLUSION: Tumor electric fields therapy is an effective and highly promising treatment modality for GBM. The full therapeutic potential of TEFT can be exploited by combined with other innovative technologies and treatments.

Efficient Charge Separation in Ag/PCN/UPDI Ternary Heterojunction for Optimized Photothermal-Photocatalytic Performance via Tandem Electric Fields.

Charge separation driven by the internal electric field is a research hotspot in photocatalysis. However, it remains challenging to accurately control the electric field to continuously accelerate the charge transfer. Herein, a strategy of constructing a tandem electric field to continuously accelerate charge transfer in photocatalysts is proposed. The plasma electric field, interface electric field, and intramolecular electric field are integrated into the Ag/g-C3N4/urea perylene imide (Ag/PCN/UPDI) ternary heterojunction to achieve faster charge separation and longer carrier lifetime. The triple electric fields function as three accelerators on the charge transport path, promoting the separation of electron-hole pairs, accelerating charge transfer, enhancing light absorption, and increasing the concentration of energetic electrons on the catalyst. The H2 evolution rate of Ag/PCN/UPDI is 16.8 times higher than that of pristine PDI, while the degradation rate of oxytetracycline is increased by 4.5 times. This new strategy will provide a groundbreaking idea for the development of high-efficiency photocatalysts.

Exciton Delocalization and Polarizability in Perylenetetracarboxylic Diimide Probed Using Electroabsorption and Fluorescence Spectroscopies.

Perylenetetracarboxylic diimide (PTCDI) is an n-type organic semiconductor molecule that has been widely utilized in numerous applications such as photocatalysis and field-effect transistors. Polarizability and dipole moment, which are inherent properties of molecules, are important parameters that determine their responses to external electric and optical fields, physical properties, and reactivity. These parameters are fundamentally important for the design of innovative materials. In this study, the effects of external electric fields on absorption and fluorescence spectra were investigated to obtain the PTCDI parameters. The PTCDI substituted by an octyl group (N,N'-Dioctyl-3,4,9,10-perylenedicarboximide) dispersed in a polymethyl methacrylate (PMMA) matrix was studied in this work. The features of vibronic progression in the absorption spectrum were analogous to those observed in solution. The red shift of the absorption band caused by the Stark effect was mainly observed in the presence of an external electric field. Changes in parameters such as the dipole moment and polarizability between the ground and the Franck-Condon excited states of the PTCDI monomer were determined. The fluorescence spectrum shows a contribution from a broad fluorescence band at wavelengths longer than the monomer fluorescence band. This broad fluorescence is ascribed to the excimer-like fluorescence of PTCDI. The effects of the electric field on the fluorescence spectrum, known as the Stark fluorescence or electrofluorescence spectrum, were measured. Fluorescence quenching is observed in the presence of an external electric field. The change in the polarizability of the monomer fluorescence band is in good agreement with that of the electroabsorption spectrum. A larger change in the polarizability was observed for the excimer-like fluorescence band than that for the monomer band. This result is consistent with exciton delocalization between PTCDI molecules in the excimer-like state.

Comparative Study of Microwave, Pulsed Electric Fields, and High Pressure Processing on the Extraction of Antioxidants from Olive Pomace.

Olive oil production is characterized by large amounts of waste, and yet is considerably highly valued. Olive pomace can serve as a cheap source of bioactive compounds (BACs) with important antioxidant activity. Novel technologies like Pulsed Electric Fields (PEF) and High Pressure (HP) and microwave (MW) processing are considered green alternatives for the recovery of BACs. Different microwave (150-600 W), PEF (1-5 kV/cm field strength, 100-1500 pulses/15 µs width), and HP (250-650 MPa) conditions, in various product/solvent ratios, methanol concentrations, extraction temperatures, and processing times were investigated. Results indicated that the optimal MW extraction conditions were 300 W at 50 °C for 5 min using 60% v/v methanol with a product/solvent ratio of 1:10 g/mL. Similarly, the mix of 40% v/v methanol with olive pomace, treated at 650 MPa for the time needed for pressure build-up (1 min) were considered as optimal extraction conditions in the case of HP, while for PEF the optimal conditions were 60% v/v methanol with a product/solvent ratio of 1:10 g/mL, treated at 5000 pulses, followed by 1 h extraction under stirring conditions. Therefore, these alternative extraction technologies could assist the conventional practice in minimizing waste production and simultaneously align with the requirements of the circular bioeconomy concept.