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1.
Cell ; 184(4): 912-930.e20, 2021 02 18.
Artículo en Inglés | MEDLINE | ID: mdl-33571430

RESUMEN

Electrical stimulation is a promising tool for modulating brain networks. However, it is unclear how stimulation interacts with neural patterns underlying behavior. Specifically, how might external stimulation that is not sensitive to the state of ongoing neural dynamics reliably augment neural processing and improve function? Here, we tested how low-frequency epidural alternating current stimulation (ACS) in non-human primates recovering from stroke interacted with task-related activity in perilesional cortex and affected grasping. We found that ACS increased co-firing within task-related ensembles and improved dexterity. Using a neural network model, we found that simulated ACS drove ensemble co-firing and enhanced propagation of neural activity through parts of the network with impaired connectivity, suggesting a mechanism to link increased co-firing to enhanced dexterity. Together, our results demonstrate that ACS restores neural processing in impaired networks and improves dexterity following stroke. More broadly, these results demonstrate approaches to optimize stimulation to target neural dynamics.


Asunto(s)
Potenciales de Acción/fisiología , Accidente Cerebrovascular/fisiopatología , Animales , Conducta Animal/fisiología , Fenómenos Biomecánicos/fisiología , Estimulación Eléctrica , Haplorrinos , Corteza Motora/fisiopatología , Redes Neurales de la Computación , Neuronas/fisiología , Análisis y Desempeño de Tareas , Factores de Tiempo
2.
Annu Rev Biochem ; 86: 387-415, 2017 06 20.
Artículo en Inglés | MEDLINE | ID: mdl-28375745

RESUMEN

What happens inside an enzyme's active site to allow slow and difficult chemical reactions to occur so rapidly? This question has occupied biochemists' attention for a long time. Computer models of increasing sophistication have predicted an important role for electrostatic interactions in enzymatic reactions, yet this hypothesis has proved vexingly difficult to test experimentally. Recent experiments utilizing the vibrational Stark effect make it possible to measure the electric field a substrate molecule experiences when bound inside its enzyme's active site. These experiments have provided compelling evidence supporting a major electrostatic contribution to enzymatic catalysis. Here, we review these results and develop a simple model for electrostatic catalysis that enables us to incorporate disparate concepts introduced by many investigators to describe how enzymes work into a more unified framework stressing the importance of electric fields at the active site.


Asunto(s)
Proteínas Bacterianas/química , Hidrolasas/química , Cetosteroides/química , Pseudomonas/enzimología , Esteroide Isomerasas/química , Proteínas Bacterianas/genética , Proteínas Bacterianas/metabolismo , Biocatálisis , Dominio Catalítico , Expresión Génica , Hidrolasas/genética , Hidrolasas/metabolismo , Cetosteroides/metabolismo , Cinética , Modelos Químicos , Simulación de Dinámica Molecular , Mutación , Pseudomonas/química , Pseudomonas/genética , Espectrofotometría Infrarroja/métodos , Electricidad Estática , Esteroide Isomerasas/genética , Esteroide Isomerasas/metabolismo , Termodinámica
3.
Annu Rev Cell Dev Biol ; 30: 317-36, 2014.
Artículo en Inglés | MEDLINE | ID: mdl-25062359

RESUMEN

Localized ion fluxes at the plasma membrane provide electrochemical gradients at the cell surface that contribute to cell polarization, migration, and division. Ion transporters, local pH gradients, membrane potential, and organization are emerging as important factors in cell polarization mechanisms. The power of electrochemical effects is illustrated by the ability of exogenous electric fields to redirect polarization in cells ranging from bacteria, fungi, and amoebas to keratocytes and neurons. Electric fields normally surround cells and tissues and thus have been proposed to guide cell polarity in development, cancer, and wound healing. Recent studies on electric field responses in model systems and development of new biosensors provide new avenues to dissect molecular mechanisms. Here, we review recent advances that bring molecular understanding of how electrochemistry contributes to cell polarity in various contexts.


Asunto(s)
Polaridad Celular/fisiología , Animales , Aniones/metabolismo , Cationes/metabolismo , División Celular , Movimiento Celular , Forma de la Célula , Dictyostelium/citología , Electroquímica , Campos Electromagnéticos , Peces , Hongos/citología , Concentración de Iones de Hidrógeno , Líquido Intracelular/química , Transporte Iónico/fisiología , Potenciales de la Membrana/fisiología , Regeneración , Electricidad Estática , Cicatrización de Heridas
4.
Small ; 20(6): e2306354, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-37775306

RESUMEN

Achieving superior photomineralization of pollutants relies on a rational design of a dual S-scheme with a robust internal electric field (IEF). In this study, to tackle the low mineralization rate in type-II In2 O3 /In2 S3 (IO/IS) systems, an organic-inorganic dual S-scheme In2 O3 /PDI/In2 S3 (IO/PDI/IS) nanostructured photocatalyst is synthesized via a method combining solvent-induced self-assembly and electrostatic forces. Due to the unique energy band position and strong IEF, the photoinduced defect-transit dual S-scheme IO/PDI/IS facilitates the degradation of lignin and antibiotics. Notably, a promising mineralization rate of 80.9% for sodium lignosulfonate (SL) is achieved. The charge transport pathway of IO/PDI/IS are further validated through the analysis of in situ X-ray photoelectron spectroscopy (in situ XPS), density functional theory calculations, and radical trapping experiments. In-depth, two possible pathways for the photocatalytic degradation of lignin are proposed based on the intermediates monitored by liquid chromatography-mass spectrometry (LC-MS). This study presents a new strategy for the design of organic-inorganic dual S-scheme photocatalysts with a robust IEF for pollutant degradation.

5.
Small ; 20(11): e2306569, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-38095443

RESUMEN

The use of 2D materials to produce hydrogen (H2 ) fuel via photocatalytic water splitting has been intensively studied. However, the simultaneous fulfillment of the three essential requirements-high photon utilization, rapid carrier transfer, and low-barrier redox reactions-for wide-pH-range production of H2 still poses a significant challenge with no additional modulation. By employing the first-principles calculations, it has been observed that the Janus ZnXY2 structures (X = Si/Ge/Sn, Y = S/Se/Te) exhibit significantly enhanced built-in electric fields (0.20-0.36 eV Å-1 ), which address the limitations intrinsically. Compared to conventional Janus membranes, the ductile ZnSnSe2 and ZnSnTe2 monolayers have stronger regulation of electric fields, resulting in improved electron mobility and excitonic nature (Ebinding = 0.50/0.35 eV). Both monolayers exhibit lower energy barriers of hydrogen evolution reaction (HER, 0.98/0.86 eV, pH = 7) and resistance to photocorrosion across pH 0-7. Furthermore, the 1% tensile strain can further boost visible light utilization and intermediate absorption. The optimal AC-type bilayer stacking configuration is conducive to enhancing electric fields for photocatalysis. Overall, Janus ZnXY2 membranes overcome the major challenges faced by conventional 2D photocatalysts via intrinsic polarization and external amelioration, enabling efficient and controllable photocatalysis without the need for doping or heterojunctions.

6.
Small ; 20(28): e2306692, 2024 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-38773907

RESUMEN

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.

7.
Chemphyschem ; : e202400648, 2024 Jul 24.
Artículo en Inglés | MEDLINE | ID: mdl-39044653

RESUMEN

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.

8.
J Microsc ; 295(2): 140-146, 2024 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-38372408

RESUMEN

Atomic electric fields in a thin GaN sample are measured with the centre-of-mass approach in 4D-scanning transmission electron microscopy (4D-STEM) using a 12-segmented STEM detector in a Spectra 300 microscope. The electric fields, charge density and potential are compared to simulations and an experimental measurement using a pixelated 4D-STEM detector. The segmented detector benefits from a high recording speed, which enables measurements at low radiation doses. However, there is measurement uncertainty due to the limited number of segments analysed in this study.

9.
Mol Biol Rep ; 51(1): 115, 2024 Jan 16.
Artículo en Inglés | MEDLINE | ID: mdl-38227267

RESUMEN

BACKGROUND: Recent studies have shown that the expression of bHLH transcription factors Hes1, Ascl1, and Oligo2 has an oscillating balance in neural stem cells (NSCs) to maintain their self-proliferation and multi-directional differentiation potential. This balance can be disrupted by exogenous stimulation. Our previous work has identified that electrical stimulation could induce neuronal differentiation of mouse NSCs. METHODS: To further evaluate if physiological electric fields (EFs)-induced neuronal differentiation is related to the expression patterns of bHLH transcription factors Hes1, Ascl1, and Oligo2, mouse embryonic brain NSCs were used to investigate the expression changes of Ascl1, Hes1 and Oligo2 in mRNA and protein levels during EF-induced neuronal differentiation. RESULTS: Our results showed that NSCs expressed high level of Hes1, while expression of Ascl1 and Oligo2 stayed at very low levels. When NSCs exited proliferation, the expression of Hes1 in differentiated cells began to decrease and oscillated at the low expression level. Oligo2 showed irregular changes in low expression level. EF-stimulation significantly increased the expression of Ascl1 at mRNA and protein levels accompanied by an increased percentage of neuronal differentiation. What's more, over-expression of Hes1 inhibited the neuronal differentiation induced by EFs. CONCLUSION: EF-stimulation directed neuronal differentiation of NSCs by promoting the continuous accumulation of Ascl1 expression and decreasing the expression of Hes1.


Asunto(s)
Factores de Transcripción con Motivo Hélice-Asa-Hélice Básico , Encéfalo , Factor de Transcripción 2 de los Oligodendrocitos , Factor de Transcripción HES-1 , Animales , Ratones , Factores de Transcripción con Motivo Hélice-Asa-Hélice Básico/genética , Diferenciación Celular , Estimulación Eléctrica , ARN Mensajero/genética , Factor de Transcripción HES-1/genética , Factor de Transcripción 2 de los Oligodendrocitos/genética
10.
Bioelectromagnetics ; 2024 Sep 16.
Artículo en Inglés | MEDLINE | ID: mdl-39279429

RESUMEN

This computational simulation study investigates the strength of transcranial magnetic stimulation (TMS)-induced electric fields (EF) in primary motor cortex (M1) and secondary motor areas. Our results reveal high interindividual variability in the strength of TMS-induced EF responses in secondary motor areas, relative to the stimulation threshold in M1. Notably, the activation of the supplementary motor area requires high-intensity stimulation, which could be attributed to the greater scalp-to-cortex distance observed over this area. These findings emphasize the importance of individualized planning using computational simulation for optimizing neuromodulation strategies targeting the cortical motor system.

11.
Sensors (Basel) ; 24(17)2024 Aug 24.
Artículo en Inglés | MEDLINE | ID: mdl-39275394

RESUMEN

When using transformer insulation oil as a liquid dielectric, the oil is easily polluted by the solid particles generated in the operation of the transformer, and these metallic impurity particles have a significant impact on the insulation performance inside the power transformer. The force of the metal particles suspended in the flow insulation oil is multidimensional, which will lead to a change in the movement characteristics of the metal particles. Based on this, this study explored the motion rules of suspended metallic impurity particles in mobile insulating oil in different electric field environments and the influencing factors. A multiphysical field model of the solid-liquid two-phase flow of single-particle metallic impurity particles in mobile insulating oil was constructed using the dynamic analysis method, and the particles' motion characteristics in the oil in different electric field environments were simulated. The motion characteristics of metallic impurity particles under conditions of different particle sizes, oil flow velocities, and insulation oil qualities and influencing factors were analyzed to provide theoretical support for the detection of impurity particles in transformer insulation oil and enable accurate estimations of the location of equipment faults. Our results show that there are obvious differences in the trajectory of metallic impurity particles under different electric field distributions. The particles will move towards the region of high field intensity under an electric field, and the metallic impurity particles will not collide with the electrode under an AC field. When the electric field intensity and particle size increase, the trajectory of the metallic impurity particles between electrodes becomes denser, and the number of collisions between particles and electrodes and the motion speed both increase. Under the condition of a higher oil flow velocity, the number of collisions between metal particles and electrodes is reduced, which reduces the possibility of particle agglomeration. When the temperature of the insulation oil changes and the quality deteriorates, its dynamic viscosity changes. With a decrease in the dynamic viscosity of the insulation oil, the movement of the metallic impurity particles between the electrodes becomes denser, the collision times between the particles and electrodes increase, and the maximum motion speed of the particles increases.

12.
Molecules ; 29(7)2024 Apr 03.
Artículo en Inglés | MEDLINE | ID: mdl-38611882

RESUMEN

This study evaluated the impact of pulsed electric fields (PEFs) combined with three-phase partitioning (TPP) extraction methods on the physicochemical properties, functional properties, and structural characterization of the soluble dietary fiber (SDF) derived from peanut shells (PS). The findings of this study indicated that the application of a PEF-TPP treatment leads to a notable improvement in both the extraction yield and purity of SDF. Consequently, the PEF-TPP treatment resulted in the formation of more intricate and permeable structures, a decrease in molecular weight, and an increase in thermal stability compared to SDFs without TPP treatment. An analysis revealed that the PEF-TPP method resulted in an increase in the levels of arabinose and galacturonic acid, leading to enhanced antioxidant capacities. Specifically, the IC50 values were lower in SDFs which underwent PEF-TPP (4.42 for DPPH and 5.07 mg/mL for ABTS) compared to those precipitated with 40% alcohol (5.54 mg/mL for DPPH, 5.56 mg/mL for ABTS) and PEF75 (6.60 mg/mL for DPPH, 7.61 mg/mL for ABTS), respectively. Notably, the SDFs which underwent PEF-TPP demonstrated the highest water- and oil-holding capacity, swelling capacity, emulsifying activity, emulsion stability, glucose adsorption, pancreatic lipase inhibition, cholesterol adsorption, nitric ion adsorption capacity, and the least gelation concentration. Based on the synthesis scores obtained through PCA (0.536 > -0.030 > -0.33), which indicated that SDFs which underwent PEF-TPP exhibited the highest level of quality, the findings indicate that PEF-TPP exhibits potential and promise as a method for preparing SDFs.


Asunto(s)
Antioxidantes , Arachis , Benzotiazoles , Ácidos Sulfónicos , Adsorción , Fibras de la Dieta
13.
Molecules ; 29(10)2024 May 08.
Artículo en Inglés | MEDLINE | ID: mdl-38792068

RESUMEN

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.

14.
Molecules ; 29(10)2024 May 14.
Artículo en Inglés | MEDLINE | ID: mdl-38792161

RESUMEN

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.


Asunto(s)
Antioxidantes , Electricidad , Microondas , Olea , Presión , Olea/química , Antioxidantes/química , Antioxidantes/aislamiento & purificación , Extractos Vegetales/química , Solventes/química , Aceite de Oliva/química , Metanol/química
15.
Molecules ; 29(16)2024 Aug 20.
Artículo en Inglés | MEDLINE | ID: mdl-39203004

RESUMEN

By increasing the permeability of the cell membrane of the treated material, pulsed electric fields (PEF) enhance the internal transport of various chemical substances. Changing the distribution of these components can modify the chemical and thermal properties of the given material. This study aimed to analyze the impact of PEF (1 kV/cm; 1 and 4 kJ/kg) applied to strawberries prior to drying by various methods (convective, infrared-convective, microwave-convective, and vacuum) on the chemical and thermal properties of the obtained dried materials (sugars content, total phenolic content, and antioxidant capacity (ABTS and DPPH assays); thermal properties (TGA and DSC); and molecular composition (FTIR)). PEF could have induced and/or enhanced sucrose inversion because, compared to untreated samples, PEF-pretreated samples were characterized by a lower share of sucrose in the total sugar content but a higher share of glucose and fructose. Reduced exposure to oxygen and decreased drying temperature during vacuum drying led to obtaining dried strawberries with the highest content of antioxidant compounds, which are sensitive to these factors. All PEF-pretreated dried strawberries exhibited a lower glass transition temperature (Tg) than the untreated samples, which confirms the increased mobility of the system after the application of an electric field.


Asunto(s)
Antioxidantes , Fragaria , Fragaria/química , Antioxidantes/química , Antioxidantes/análisis , Electricidad , Desecación/métodos , Sacarosa/química , Fenoles/análisis , Fenoles/química , Espectroscopía Infrarroja por Transformada de Fourier
16.
Angew Chem Int Ed Engl ; 63(29): e202406113, 2024 Jul 15.
Artículo en Inglés | MEDLINE | ID: mdl-38687257

RESUMEN

Separation membranes with homogeneous charge channels are the mainstream to reject charged mass by forming electrical double layer (EDL). However, the EDL often compresses effective solvent transport space and weakens channel-ion interaction. Here, built-in electric fields (BIEFs) are constructed in lamellar membranes by assembling the heterostructured nanosheets, which contain alternate positively-charged nanodomains and negatively-charged nanodomains. We demonstrate that the BIEFs are perpendicular to horizontal channel and the direction switches alternately, significantly weakening the EDL effect and forces ions to repeatedly collide with channel walls. Thus, highly efficient rejection for charged mass (salts, dyes, and organic acids/bases) and ultrafast water transport are achieved. Moreover, for desalination on four-stage filtration option, salt rejection reaches 99.9 % and water permeance reaches 19.2 L m-2 h-1 bar-1. Such mass transport behavior is quite different from that in homogeneous charge channels. Furthermore, the ion transport behavior in nanochannels is elucidated by validating horizontal projectile motion model.

17.
J Orthop Traumatol ; 25(1): 17, 2024 Apr 15.
Artículo en Inglés | MEDLINE | ID: mdl-38622334

RESUMEN

BACKGROUND: Capacitively coupling electric fields (CCEF) is a method of non-invasive biophysical stimulation that enhances fracture repair and spinal fusion. This multicentre randomized controlled trial aimed to further examine the roles of CCEF in (1) the resolution of vertebral bone marrow oedema (VBME) using a follow-up MRI study and (2) pain relief, analgesic drug consumption and quality of life improvement in stimulated patients who were referred with acute vertebral fragility fractures (VFFs) compared to non-stimulated patients. METHODS: Between September 2016 and December 2019, patients who were referred to the spine centres that participated in this multicentre randomized clinical study with acute VFFs of type OF1 or OF2 were included in the present study. All the VFFs were conservatively managed according to Good Clinical Practice. Moreover, the patients were randomized into two groups: the CCEF group received, as an adjunct to the clinical study protocol, biophysical stimulation with a CCEF device (Osteospine, IGEA) for 8 h per day for 60 days, whereas the control group was treated according to the clinical study protocol. At baseline (T0), the 30-day follow-up (T1), the 60-day follow-up (T2), and the 6-month follow-up (T3), each patient underwent clinical evaluation using the Visual Analogue Scale (VAS) for Pain and the Oswestry Disability Index (ODI). Analgesic therapy with paracetamol 1000 mg tablets for 7 days-or longer, depending on the pain intensity-was performed; patients were required to report their paracetamol consumption on a specific sheet between study day 8 to 180 days of follow-up. MRI studies of the thoracolumbar spine were performed at 0 (T0), 30 (T1) and 60 days of follow-up (T2) using a 1.5-T MRI system in all of the centres that took part in the study. For each VBME area examined via MRI, the vertebral body geometry (i.e. anterior wall height/posterior wall height and vertebral kyphosis) were assessed. RESULTS: A total of 66 patients (male: 9, 13.63%; mean age: 73.15 years old) with 69 VFFs were included in the present study and randomized as follows: 33 patients were included in the control group and the remaining 33 patients were randomized into the CCEF group. In the CCEF group, good compliance with CCEF therapy was observed (adherence = 94%), and no adverse effects were recorded. In the stimulated patients, faster VBME resolution and significantly less vertebral body collapse during follow-up were observed compared to the control patients. Moreover, in the active group, faster pain reduction and improvement in the ODI mean score were observed. Stimulated patients also reported a significantly lower paracetamol consumption rate from the third follow-up after treatment until the 6-month follow-up. In terms of sex-related differences, in the CCEF group, VBME showed a faster resolution in male patients compared with females. CONCLUSION: Biophysical stimulation with CCEF, as an adjunct to traditional conservative treatment, is a useful tool to hasten the VBME resolution process and prevent vertebral body deformation. These MRI findings also correlate with faster back pain resolution and quality of life improvement. From the third follow-up after treatment until the 6-month follow-up, stimulated patients reported a significantly lower paracetamol consumption than control patients, even though back pain and quality of life showed no significant differences between the two groups. LEVEL OF EVIDENCE: II. Trial Registration Register: ClinicalTrials.gov, number: NCT05803681.


Asunto(s)
Fracturas por Compresión , Fracturas de la Columna Vertebral , Femenino , Humanos , Masculino , Anciano , Acetaminofén , Calidad de Vida , Estudios Prospectivos , Dolor de Espalda , Fracturas de la Columna Vertebral/diagnóstico por imagen , Fracturas de la Columna Vertebral/terapia , Analgésicos , Fracturas por Compresión/terapia , Resultado del Tratamiento
18.
Small ; 19(32): e2301189, 2023 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-37069774

RESUMEN

In situ electrochemical activation brings unexpected electrochemical performance improvements to electrode materials, while the mechanism behind is still needed to study deeply. Herein, an in situ electrochemically approach is developed for the activation of heterointerface MnOx /Co3 O4 by inducing Mn-defect, wherein the Mn defects are formed through a charge process that converts the MnOx with poor electrochemical activities toward Zn2+ into high electrochemically active cathode for aqueous zinc-ion batteries (ZIBs). Guided by the coupling engineering strategy, the heterointerface cathode exhibits an intercalation/conversion dual-mechanism without structural collapse during storage/release of Zn2+ . The heterointerfaces between different phases can generate built-in electric fields, reducing the energy barrier for ion migration and facilitating electron/ion diffusion. As a consequence, the dual-mechanism MnOx /Co3 O4 shows an outstanding fast charging performance and maintains a capacity of 401.03 mAh g-1 at 0.1 A g-1 . More importantly, a ZIB based on MnOx /Co3 O4 delivered an energy density of 166.09 Wh kg-1 at an ultrahigh power density of 694.64 W kg-1 , which outperforms those of fast charging supercapacitors. This work provides insights for using defect chemistry to introduce novel properties in active materials for highly for high-performance aqueous ZIBs.

19.
Cancer Cell Int ; 23(1): 110, 2023 Jun 07.
Artículo en Inglés | MEDLINE | ID: mdl-37287008

RESUMEN

PURPOSE: Currently, tumor-treating field (TTField) therapy utilizes a single "optimal" frequency of electric fields to achieve maximal cell death in a targeted population of cells. However, because of differences in cell size, shape, and ploidy during mitosis, optimal electric field characteristics for universal maximal cell death may not exist. This study investigated the anti-mitotic effects of modulating electric field frequency as opposed to utilizing uniform electric fields. METHODS: We developed and validated a custom device that delivers a wide variety of electric field and treatment parameters including frequency modulation. We investigated the efficacy of frequency modulating tumor-treating fields on triple-negative breast cancer cells compared to human breast epithelial cells. RESULTS: We show that frequency-modulated (FM) TTFields are as selective at treating triple-negative breast cancer (TNBC) as uniform TTFields while having a greater efficacy for combating TNBC cell growth. TTField treatment at a mean frequency of 150 kHz with a frequency range of ± 10 kHz induced apoptosis in a greater number of TNBC cells after 24 h as compared to unmodulated treatment which led to further decreased cell viability after 48 h. Furthermore, all TNBC cells died after 72 h of FM treatment while cells that received unmodulated treatment were able to recover to cell number equivalent to the control. CONCLUSION: TTFields were highly efficacious against TNBC growth, FM TTFields showed minimal effects on epithelial cells similar to unmodulated treatment.

20.
Nanotechnology ; 34(46)2023 Aug 31.
Artículo en Inglés | MEDLINE | ID: mdl-37582342

RESUMEN

The continuum theory has been used to analyze the polarization, ion crowding, and electrostatic forces of the electric double layer in the electrode materials having simple cubic (SC), body-centered cubic (BCC), and face-centered cubic (FCC) morphologies. The study manifests the effect of thickness of electrodes, electrode's particle size, and porosity on electric double-layer specific capacitance (EDLC). Electrochemical interference and the specific capacitance depend on the packing factor. The larger particle size decreases the specific capacitance, but porosity increases due to more surface area. Due to symmetry, SC, BCC, and FCC morphologies have 1, 3, and 5 spheres in a unit cell. The number of unit cells is varied from 1 to 100 in model 1 to analyze the effect of electrode thickness. Model 2 has three unit cells to understand the effect of porosity, and only pore lengths are varied. The critical thickness of the electrodes is the integer multiples of 1.71µm in all the morphologies. The Stern layer-specific capacitance is 167.6µF cm-2in all cases. The EDLC in BCC is around 5.6-7.6µF cm-2in the steady state that is intermediate between SC and FCC morphologies. The more dense packing of carbon particles in a unit cell increases the energy storage capabilities of electrodes. The average electrode permittivity slightly decreases due to the combined effect of the high electric field, status of polarization, and electrode particle size. The least optical transmission of electrodes is 98.35%.

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