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1.
Adv Mater ; : e2411248, 2024 Oct 03.
Artículo en Inglés | MEDLINE | ID: mdl-39363668

RESUMEN

The rapid development of wearable electronics, personal mobile equipment, and Internet of Things systems demands smart textiles that integrate multiple functions with enhanced durability. Herein, the study reports robust and multifunctional textiles with energy harvesting, electromagnetic interference (EMI) shielding, flame resistance, and Joule heating capabilities, fabricated by a facile yet effective integration method using the deposition of cross-linked MXene (Ti3C2Tx), poly(vinyl alcohol) (PVA), and poly(acrylic acid) (PAA) onto traditional Korean paper, Hanji via vacuum filtration. Comprehensive analyses confirm robust cross-linking, structural integrity, and interface stability in the MXene/PVA/PAA-Hanji (MPP-H) textiles, which synergistically boost their multifunctional performance. The MPP-H textiles exhibit remarkable power generation lasting over 60 min with a power density of 102.2 µW cm-3 and an energy density of 31.0 mWh cm-3 upon the application of 20 µL of NaCl solution. The EMI shielding effectiveness (SE) per unit thickness in the X-band (8.2-12.4 GHz) is up to 437.6 dB mm-1, with the ratio of absorption to reflection reaching 4.5, outperforming existing EMI shielding materials. Superior thermo-chemo-mechanical properties (flame resistance, rapid Joule heating, durability, and washability) further demonstrate their versatile usability. The MPP-H enables diverse functionalities within a single, robust textile through a scalable fabrication method, offering transformative potential for wearable and mobility platforms.

2.
Nat Commun ; 15(1): 7849, 2024 Sep 08.
Artículo en Inglés | MEDLINE | ID: mdl-39245666

RESUMEN

Reactive capture of carbon dioxide (CO2) offers an electrified pathway to produce renewable carbon monoxide (CO), which can then be upgraded into long-chain hydrocarbons and fuels. Previous reactive capture systems relied on hydroxide- or amine-based capture solutions. However, selectivity for CO remains low (<50%) for hydroxide-based systems and conventional amines are prone to oxygen (O2) degradation. Here, we develop a reactive capture strategy using potassium glycinate (K-GLY), an amino acid salt (AAS) capture solution applicable to O2-rich CO2-lean conditions. By employing a single-atom catalyst, engineering the capture solution, and elevating the operating temperature and pressure, we increase the availability of dissolved in-situ CO2 and achieve CO production with 64% Faradaic efficiency (FE) at 50 mA cm-2. We report a measured CO energy efficiency (EE) of 31% and an energy intensity of 40 GJ tCO-1, exceeding the best hydroxide- and amine-based reactive capture reports. The feasibility of the full reactive capture process is demonstrated with both simulated flue gas and direct air input.

3.
Medicina (Kaunas) ; 60(9)2024 Sep 05.
Artículo en Inglés | MEDLINE | ID: mdl-39336493

RESUMEN

Background and Objective: This randomized controlled trial investigated the influence of perioperative lidocaine administration on the postoperative inflammatory response in patients undergoing robot-assisted radical prostatectomy, with the results having potential implications for postoperative recovery and cancer recurrence via neutrophil extracellular trapping (NETosis). Materials and Methods: In total, 58 patients with localized prostate cancer were randomly assigned to receive an intravenous infusion of 2% lidocaine or a saline placebo intraoperatively. Serum levels of interleukin (IL)-6, IL-10, and IL-17, tumor necrosis factor(TNF)-α, interferon(IFN)-γ, neutrophil elastase (NE), citrullinated histone3 (CitH3), and myeloperoxidase (MPO) were determined preoperatively and at 24 h postoperatively. Biochemical recurrence (BCR) was assessed over a follow-up period of 2 years. Results: The lidocaine group showed a significant change in MPO, a greater reduction in IL-10 level, and a smaller increase in the NE level compared to the placebo group, suggesting a modulatory effect of lidocaine on certain anti-inflammatory and neuroendocrine pathways. No significant difference in the BCR rate was observed between the two groups. Conclusions: Perioperative lidocaine administration selectively modulates certain inflammatory and neuroendocrine responses after robot-assisted radical prostatectomy surgery, potentially influencing recovery outcomes. These findings highlight the need for further investigations of the role of lidocaine in Enhanced Recovery After Surgery protocols, particularly in oncologic surgeries.


Asunto(s)
Citocinas , Lidocaína , Prostatectomía , Neoplasias de la Próstata , Procedimientos Quirúrgicos Robotizados , Humanos , Lidocaína/uso terapéutico , Lidocaína/administración & dosificación , Prostatectomía/métodos , Masculino , Persona de Mediana Edad , Anciano , Citocinas/sangre , Neoplasias de la Próstata/cirugía , Neoplasias de la Próstata/sangre , Procedimientos Quirúrgicos Robotizados/métodos , Trampas Extracelulares/efectos de los fármacos , Neutrófilos/efectos de los fármacos , Anestésicos Locales/uso terapéutico , Anestésicos Locales/administración & dosificación
4.
J Am Chem Soc ; 146(40): 27701-27712, 2024 Oct 09.
Artículo en Inglés | MEDLINE | ID: mdl-39331404

RESUMEN

The electrochemical reduction of CO2 in acidic media offers the advantage of high carbon utilization, but achieving high selectivity to C2+ products at a low overpotential remains a challenge. We identified the chemical instability of oxide-derived Cu catalysts as a reason that advances in neutral/alkaline electrolysis do not translate to acidic conditions. In acid, Cu ions leach from Cu oxides, leading to the deactivation of the C2+-active sites of Cu nanoparticles. This prompted us to design acid-stable Cu cluster precatalysts that are reduced in situ to active Cu nanoparticles in strong acid. Operando Raman and X-ray spectroscopy indicated that the bonding between the Cu cluster precatalyst ligand and in situ formed Cu nanoparticles preserves a high density of undercoordinated Cu sites, resulting in a C2H4 Faradaic efficiency of 62% at a low overpotential. The result is a 1.4-fold increase in energy efficiency compared with previous acidic CO2-to-C2+ electrocatalytic systems.

5.
Psychiatry Investig ; 21(7): 746-754, 2024 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-39089700

RESUMEN

OBJECTIVE: The abuse of prescription drugs and over-the-counter medicines has been a major issue addressed as a serious public health problem worldwide. This study explored factors contributing to substance abuse in Korea by examining the status of substance abuse among Korean adults and evaluating their knowledge, attitudes, and intentions toward substance abuse. METHODS: Data were collected online from a sample of participants 19 years old or older from May 20 to June 1, 2020 (n=1,020). The survey consisted of questions on demographics, perceptions of drug risk, motives for drug use, and attitudes toward drug addiction treatment. Principal component and multiple logistic regression analyses were used to explore the factors contributing to the perception of drug abuse. RESULTS: In the multivariate regression analysis, overconfidence in handling drug usage, acceptance of addictive substances, and affirmation of public support for drug abuse were associated with opioid abuse (Nagelkerke R2=0.486), and additionally affirmation of legal cannabis usage and motivation to use diet pills were associated with diet pill abuse (Nagelkerke R2=0.569). CONCLUSION: The findings of this study suggest that the actual situation of substance abuse among Korean adults increases awareness of and attitudes toward drug use related to substance abuse.

6.
J Am Chem Soc ; 146(18): 12556-12564, 2024 May 08.
Artículo en Inglés | MEDLINE | ID: mdl-38660792

RESUMEN

Transition metal nitride (TMN)-based nanostructures have emerged as promising materials for diverse applications in electronics, photonics, energy storage, and catalysis due to their highly desirable physicochemical properties. However, synthesizing TMN-based nanostructures with designed compositions and morphologies poses challenges, especially in the solution phase. The cation exchange reaction (CER) stands out as a versatile postsynthetic strategy for preparing nanostructures that are otherwise inaccessible through direct synthesis. Nevertheless, exploration of the CER in TMNs lags behind that in metal chalcogenides and metal phosphides. Here, we demonstrate cation exchange in colloidal metal nitride nanocrystals, employing Cu3N nanocrystals as starting materials to synthesize Ni4N and CoN nanocrystals. By controlling the reaction conditions, Cu3N@Ni4N and Cu3N@CoN core@shell heterostructures with tunable compositions can also be obtained. The Ni4N and CoN nanocrystals are evaluated as catalysts for the electrochemical oxygen evolution reaction (OER). Remarkably, CoN nanocrystals demonstrate superior OER performance with a low overpotential of 286 mV at 10 mA·cm-2, a small Tafel slope of 89 mV·dec-1, and long-term stability. Our CER approach in colloidal TMNs offers a new strategy for preparing other metal nitride nanocrystals and their heterostructures, paving the way for prospective applications.

7.
J Integr Complement Med ; 30(9): 848-857, 2024 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-38530093

RESUMEN

Introduction: The therapeutic potential of phytoncide fragrances may be optimal for patients with mild cognitive impairment (MCI) that display complex symptomatology. This study aimed to explore the clinical value of phytoncide by evaluating its electrophysiological effects in patients with MCI. Materials and Methods: This was a double-blind, randomized controlled trial. A total of 24 community-dwelling patients were randomly assigned to either a phytoncide or no-odor group. Participants wore a dental mask, for 30 min at rest that had either the fragrance stimulus or water added to it. The quantitative electroencephalography (EEG) during the resting state was recorded before and after a single intervention. Results: There were significant interaction effects in absolute EEG-power values in the occipital (F = 6.52, p = 0.018) and parietal (F = 5.41, p = 0.030) left hemisphere at ß frequency. Phytoncide odor significantly decreased low and high ß activity in the occipital (corrected p = 0.009) and parietal (corrected p = 0.047) left hemisphere, respectively. In source localization, phytoncide odor significantly decreased deep source activation in the left inferior and middle frontal gyri at ß 2 frequency band compared with the no-odor group (threshold = 4.25, p < 0.05). Conclusions: Reductions in ß, indicative of anxiety, depression, and stress, suggest relief from emotion-related symptoms that are common in patients with MCI. Trial Registration: Clinical Trials Registry Korea (registration: KCT0007317).


Asunto(s)
Encéfalo , Disfunción Cognitiva , Electroencefalografía , Odorantes , Humanos , Disfunción Cognitiva/tratamiento farmacológico , Disfunción Cognitiva/fisiopatología , Método Doble Ciego , Masculino , Femenino , Anciano , Electroencefalografía/efectos de los fármacos , Encéfalo/efectos de los fármacos , Encéfalo/fisiopatología , Persona de Mediana Edad , Aromaterapia/métodos
8.
Clin Psychopharmacol Neurosci ; 22(1): 95-104, 2024 Feb 29.
Artículo en Inglés | MEDLINE | ID: mdl-38247416

RESUMEN

Objective: : Insomnia is associated with elevated high-frequency electroencephalogram power in the waking state. Although affective symptoms (e.g., depression and anxiety) are commonly comorbid with insomnia, few reports distinguished objective sleep disturbance from affective symptoms. In this study, we investigated whether daytime electroencephalographic activity explains insomnia, even after controlling for the effects of affective symptoms. Methods: : A total of 107 participants were divided into the insomnia disorder (n = 58) and healthy control (n = 49) groups using the Mini-International Neuropsychiatric Interview and diagnostic criteria for insomnia disorder. The participants underwent daytime resting-state electroencephalography sessions (64 channels, eye-closed). Results: : The insomnia group showed higher levels of anxiety, depression, and insomnia than the healthy group, as well as increased beta [t(105) = -2.56, p = 0.012] and gamma [t(105) = -2.44, p = 0.016] spectra. Among all participants, insomnia symptoms positively correlated with the intensity of beta (r = 0.28, p < 0.01) and gamma (r = 0.25, p < 0.05) spectra. Through hierarchical multiple regression, the beta power showed the additional ability to predict insomnia symptoms beyond the effect of anxiety (ΔR2 = 0.041, p = 0.018). Conclusion: : Our results showed a significant relationship between beta electroencephalographic activity and insomnia symptoms, after adjusting for other clinical correlates, and serve as further evidence for the hyperarousal theory of insomnia. Moreover, resting-state quantitative electroencephalography may be a supplementary tool to assess insomnia.

9.
Nat Mater ; 23(1): 108-115, 2024 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-37919351

RESUMEN

Multi-metal oxides in general and perovskite oxides in particular have attracted considerable attention as oxygen evolution electrocatalysts. Although numerous theoretical studies have been undertaken, the most promising perovskite-based catalysts continue to emerge from human-driven experimental campaigns rather than data-driven machine learning protocols, which are often limited by the scarcity of experimental data on which to train the models. This work promises to break this impasse by demonstrating that active learning on even small datasets-but supplemented by informative structural-characterization data and coupled with closed-loop experimentation-can yield materials of outstanding performance. The model we develop not only reproduces several non-obvious and actively studied experimental trends but also identifies a composition of a perovskite oxide electrocatalyst exhibiting an intrinsic overpotential at 10 mA cm-2oxide of 391 mV, which is among the lowest known of four-metal perovskite oxides.

10.
Clin EEG Neurosci ; 55(5): 531-542, 2024 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-38105601

RESUMEN

As depressive symptom is considered a prodrome, a risk factor for progression from mild cognitive impairment (MCI) to dementia, improving depressive symptoms should be considered a clinical priority in patients with MCI undergoing transcranial direct current stimulation (tDCS) intervention. We aimed to comprehensively evaluate the efficacy of the home-based and remotely monitored tDCS in patients with both MCI and depression, by integrating cognitive, psychological, and electrophysiological indicators. In a 6-week, randomized, double blind, and sham-controlled study, 37 community-dwelling patients were randomly assigned to either an active or a sham stimulation group, and received 30 home-based sessions of 2 mA tDCS for 30 min with the anode located over the left and cathode over the right dorsolateral prefrontal cortex. We measured depressive symptoms, neurocognitive function, and resting-state electroencephalography. In terms of effects of both depressive symptoms and cognitive functions, active tDCS was not significantly different from sham tDCS. However, compared to sham stimulation, active tDCS decreased and increased the activation of delta and beta frequencies, respectively. Moreover, the increase in beta activity was correlated with the cognitive enhancement only in the active group. It was not possible to reach a definitive conclusion regarding the efficacy of tDCS on depression and cognition in patients with both MCI and depression. Nevertheless, the relationship between the changes of electrophysiology and cognitive performance suggests potential neuroplasticity enhancement implicated in cognitive processes by tDCS.


Asunto(s)
Disfunción Cognitiva , Depresión , Electroencefalografía , Estimulación Transcraneal de Corriente Directa , Humanos , Estimulación Transcraneal de Corriente Directa/métodos , Disfunción Cognitiva/terapia , Disfunción Cognitiva/fisiopatología , Masculino , Femenino , Método Doble Ciego , Anciano , Depresión/terapia , Depresión/fisiopatología , Electroencefalografía/métodos , Persona de Mediana Edad , Resultado del Tratamiento , Cognición/fisiología
11.
Gland Surg ; 12(11): 1636-1641, 2023 Nov 24.
Artículo en Inglés | MEDLINE | ID: mdl-38107496

RESUMEN

Background: Pregnancy is associated with thyroid nodule formation and increased size. However, an acute increase in thyroid cysts during cesarean section is unusual. Case Description: We describe the case of a 23-year-old primiparous woman at 37 weeks of gestation, without a history of thyroid disease, who underwent a cesarean section under general anesthesia. When the baby was delivered after induction of general anesthesia, the patient's airway pressure increased by approximately 5-7 mmHg, and her blood pressure increased to 170/78 mmHg. After delivery of the baby, the mother's anterior region of the neck began to swell, and ultrasonography revealed a large cystic mass. Even after aspiration of approximately 120 mL of dark brown intra-cystic fluid, the neck swelled again. Airway and blood pressure decreased after delivery and remained within the normal range until the end of surgery. Computed tomography performed after recovery from anesthesia revealed an approximately 320 mL-sized hemorrhagic cyst in the left thyroid gland with right tracheal deviation. Despite repeated aspirations and two alcohol ablations, the cyst's size increased rapidly, and the patient underwent radiofrequency ablation. Conclusions: This case indicates that rapid increases in intrathoracic and blood pressure could precipitate a rapid increase in pre-existing thyroid cysts in a parturient during delivery.

12.
ACS Nano ; 17(21): 21470-21479, 2023 Nov 14.
Artículo en Inglés | MEDLINE | ID: mdl-37847158

RESUMEN

Single-atom photocatalysis has shown potential in various single-step organic transformations, but its use in multistep organic transformations in one reaction systems has rarely been achieved. Herein, we demonstrate atomic site orthogonality in the M1/C3N4 system (where M = Pd or Ni), enabling a cascade photoredox reaction involving oxidative and reductive reactions in a single system. The system utilizes visible-light-generated holes and electrons from C3N4, driving redox reactions (e.g., oxidation and fluorination) at the surface of C3N4 and facilitating cross-coupling reactions (e.g., C-C and C-O bond formation) at the metal site. The concept is generalized to different systems of Pd and Ni, thus making the catalytic site-orthogonal M1/C3N4 system an ideal photocatalyst for improving the efficiency and selectivity of multistep organic transformations.

13.
Alcohol ; 112: 1-7, 2023 11.
Artículo en Inglés | MEDLINE | ID: mdl-37225110

RESUMEN

BACKGROUND: Most findings on the pathophysiology of alcoholism are based on studies using resting-state electroencephalography (EEG). There are few studies on cue-induced craving and on its utility as an electrophysiological index. We examined quantitative EEG (qEEG) activities in alcoholics and social drinkers exposed to video cues and compared their association with subjective alcohol craving and other related psychiatric symptoms, including anxiety and depression. METHODS: This is a between-subjects design. Adult male alcoholics (n = 34) and healthy social drinkers (n = 33) participated. In a laboratory, EEGs were recorded while the participants were presented with craving-inducing video stimuli. Measures used were the Visual Analog Scale (VAS) for subjective alcohol craving, Alcohol Urge Questionnaire (AUQ), Michigan Alcoholism Screening Test (MAST), Beck Anxiety Inventory (BAI), and Beck Depression Inventory (BDI) scores. RESULTS: One-way analysis of covariance with age showed that alcoholics had significantly increased beta activity in the right DLPFC region (F4) (F = 4.029, p = 0.049), compared to social drinkers when craving-inducing stimuli were presented. Beta activity at the F4 electrode was positively correlated with AUQ (r = .284, p = 0.021), BAI (r = .398, p = 0.001), BDI (r = .291, p = 0.018), and changes in VAS (r = .292, p = 0.017) scores in both alcoholics and social drinkers. In alcoholics, beta activity was significantly correlated with BAI (r = .392, p = 0.024). CONCLUSIONS: These findings imply functional importance of hyperarousal and negative emotions upon exposure to craving-inducing cues. Frontal EEG indices with beta power could serve as an objective electrophysiological index of craving induced by individually tailored video cues in alcohol consumption behavior.


Asunto(s)
Alcoholismo , Adulto , Humanos , Masculino , Alcoholismo/psicología , Ansia , Consumo de Bebidas Alcohólicas/psicología , Señales (Psicología) , Etanol , Electroencefalografía
14.
Adv Mater ; 35(19): e2207666, 2023 May.
Artículo en Inglés | MEDLINE | ID: mdl-36854306

RESUMEN

Single-atom nanozymes (SAzymes) are considered promising alternatives to natural enzymes. The catalytic performance of SAzymes featuring homogeneous, well-defined active structures can be enhanced through elucidating structure-activity relationship and tailoring physicochemical properties. However, manipulating enzymatic properties through structural variation is an underdeveloped approach. Herein, the synthesis of edge-rich Fe single-atom nanozymes (FeNC-edge) via an H2 O2 -mediated edge generation is reported. By controlling the number of edge sites, the peroxidase (POD)- and oxidase (OXD)-like performance is significantly enhanced. The activity enhancement results from the presence of abundant edges, which provide new anchoring sites to mononuclear Fe. Experimental results combined with density functional theory (DFT) calculations reveal that FeN4 moieties in the edge sites display high electron density of Fe atoms and open N atoms. Finally, it is demonstrated that FeNC-edge nanozyme effectively inhibits tumor growth both in vitro and in vivo, suggesting that edge-tailoring is an efficient strategy for developing artificial enzymes as novel catalytic therapeutics.


Asunto(s)
Colorantes , Peroxidasa , Catálisis , Peroxidasas , Relación Estructura-Actividad
15.
ACS Nano ; 16(10): 16529-16538, 2022 Oct 25.
Artículo en Inglés | MEDLINE | ID: mdl-36153951

RESUMEN

Sustainable energy-conversion and chemical-production require catalysts with high activity, durability, and product-selectivity. Metal/oxide hybrid structure has been intensively investigated to achieve promising catalytic performance, especially in neutral or alkaline electrocatalysis where water dissociation is promoted near the oxide surface for (de)protonation of intermediates. Although catalytic promise of the hybrid structure is demonstrated, it is still challenging to precisely modulate metal/oxide interfacial interactions on the nanoscale. Herein, we report an effective strategy to construct rich metal/oxide nano-interfaces on conductive carbon supports in a surfactant-free and self-terminated way. When compared to the physically mixed Pd/CeO2 system, a much higher degree of interface formation was identified with largely improved hydrogen oxidation reaction (HOR) kinetics. The benefits of the rich metal-CeO2 interface were further generalized to Pd alloys for optimized adsorption energy, where the Pd3Ni/CeO2/C catalyst shows superior performance with HOR selectivity against CO poisoning and shows long-term stability. We believe this work highlights the importance of controlling the interfacial junctions of the electrocatalyst in simultaneously achieving enhanced activity, selectivity, and stability.

16.
Nano Lett ; 22(9): 3636-3644, 2022 May 11.
Artículo en Inglés | MEDLINE | ID: mdl-35357196

RESUMEN

Exposing facet and surface strain are critical factors affecting catalytic performance but unraveling the composition-dependent activity on specific facets under strain-controlled environment is still challenging due to the synthetic difficulties. Herein, we achieved a (001) facet-defined Co-Mn spinel oxide surface with different surface compositions using epitaxial growth on Co3O4 nanocube template. We adopted composition gradient synthesis to relieve the strain layer by layer, minimizing the surface strain effect on catalytic activity. In this system, experimental and calculational analyses of model oxygen reduction reaction (ORR) activity reveals a volcano-like trend with Mn/Co ratios because of an adequate charge transfer from octahedral-Mn to neighboring Co. Co0.5Mn0.5 as an optimized Mn/Co ratio exhibits both outstanding ORR activity (0.894 V vs RHE in 1 M KOH) and stability (2% activity loss against chronoamperometry). By controlling facet and strain, this study provides a well-defined platform for investigating composition-structure-activity relationships in electrocatalytic processes.

17.
Acta Crystallogr D Struct Biol ; 78(Pt 1): 104-112, 2022 Jan 01.
Artículo en Inglés | MEDLINE | ID: mdl-34981766

RESUMEN

The YxaL protein was isolated from the soil bacterium Bacillus velezensis and has been shown to promote the root growth of symbiotic plants. YxaL has further been suggested to act as an exogenous signaling protein to induce the growth and branching of plant roots. Amino acid sequence analysis predicted YxaL to exhibit an eight-bladed ß-propeller fold stabilized by six tryptophan-docking motifs and two modified motifs. Protein engineering to improve its structural stability is needed to increase the utility of YxaL as a plant growth-promoting factor. Here, the crystal structure of YxaL from B. velezensis was determined at 1.8 Šresolution to explore its structural features for structure-based protein engineering. The structure showed the typical eight-bladed ß-propeller fold with structural variations in the third and fourth blades, which may decrease the stability of the ß-propeller fold. Engineered proteins targeting the modified motifs were subsequently created. Crystal structures of the engineered YxaL proteins showed that the typical tryptophan-docking interaction was restored in the third and fourth blades, with increased structural stability, resulting in improved root growth-promoting activity in Arabidopsis seeds. The work is an example of structure-based protein engineering to improve the structural stability of ß-propellor fold proteins.


Asunto(s)
Bacillus/química , Reguladores del Crecimiento de las Plantas/química , Ingeniería de Proteínas/métodos , Bacillus/genética , Cristalografía por Rayos X , Modelos Moleculares , Estructura Molecular , Mutagénesis Sitio-Dirigida , Dominios y Motivos de Interacción de Proteínas , Triptófano/química
18.
Adv Mater ; 34(8): e2107868, 2022 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-34837257

RESUMEN

Multi-metal oxide (MMO) materials have significant potential to facilitate various demanding reactions by providing additional degrees of freedom in catalyst design. However, a fundamental understanding of the (electro)catalytic activity of MMOs is limited because of the intrinsic complexity of their multi-element nature. Additional complexities arise when MMO catalysts have crystalline structures with two different metal site occupancies, such as the spinel structure, which makes it more challenging to investigate the origin of the (electro)catalytic activity of MMOs. Here, uniform-sized multi-metal spinel oxide nanoparticles composed of Mn, Co, and Fe as model MMO electrocatalysts are synthesized and the contributions of each element to the structural flexibility of the spinel oxides are systematically studied, which boosts the electrocatalytic oxygen reduction reaction (ORR) activity. Detailed crystal and electronic structure characterizations combined with electrochemical and computational studies reveal that the incorporation of Co not only increases the preferential octahedral site occupancy, but also modifies the electronic state of the ORR-active Mn site to enhance the intrinsic ORR activity. As a result, nanoparticles of the optimized catalyst, Co0.25 Mn0.75 Fe2.0 -MMO, exhibit a half-wave potential of 0.904 V (versus RHE) and mass activity of 46.9 A goxide -1 (at 0.9 V versus RHE) with promising stability.

19.
J Affect Disord ; 295: 856-864, 2021 12 01.
Artículo en Inglés | MEDLINE | ID: mdl-34706456

RESUMEN

BACKGROUND: Cranial Electrotherapy Stimulation (CES) is a promising non-invasive brain stimulation technique with the potential to alleviate anxiety. We examined the effectiveness of home-based CES with novel, headphone-like, in-ear electrodes on anxiety-related symptoms and resting-state brain activity. METHODS: This study spanned 3-weeks, with randomized, double blind, and active-controlled design. Nonclinical volunteers experiencing daily anxiety were randomly assigned to either the active or the sham groups. CES provides an alternating current (10 Hz frequency, 500 µA intensity), connected to smartphone recording treatment logs. Participants treated themselves with 20 trials of CES at home. We evaluated the effectiveness using State-Trait Anxiety Inventory (STAI), Beck Depression Inventory (BDI), Wisconsin Card Sort Test (WCST), and resting-state electroencephalography (EEG). RESULTS: The active group showed a significant improvement in state-anxiety compared to sham, while there was a statistical trend in the WCST-Category Completed (p = .061) and no change in depression. In EEG analysis, the active group showed significantly increased relative power for theta in the left frontal region compared with the sham, and this significantly correlated with the changes in state-anxiety. The active group exhibited significantly increased high-beta source activity in cuneus and middle occipital gyrus after intervention compared with the baseline. LIMITATIONS: This study had a relatively short treatment period and small sample size. CONCLUSIONS: Our findings provide the first electrophysiological evidence for CES for novel in-ear electrodes to improve anxiety. The modulatory effects of CES on resting-state oscillations of EEG imply that CES could beneficially affect functional brain activity.


Asunto(s)
Terapia por Estimulación Eléctrica , Ansiedad/terapia , Trastornos de Ansiedad , Encéfalo , Método Doble Ciego , Electrodos , Humanos
20.
J Psychiatr Res ; 141: 248-256, 2021 09.
Artículo en Inglés | MEDLINE | ID: mdl-34256276

RESUMEN

Neuromodulation has gained attention as a potential non-pharmacological intervention for mild cognitive impairment (MCI). However, no studies have directly compared the effects of transcranial alternating current stimulation (tACS) with transcranial direct current stimulation (tDCS) on MCI patients. We aimed to identify the more promising and efficient therapeutic option between tACS and tDCS for cognitive enhancement in MCI patients. We compared the effects of gamma-tACS with tDCS on cognitive function and electroencephalography (EEG) in MCI patients. In this sham-controlled, double-blinded, repeated-measures study with the order of the stimulation counterbalanced across patients (n = 20), both gamma-tACS (40 H z) and tDCS were administered at the same intensity (2 mA) in the dorsolateral prefrontal cortex for 30 min. Cognitive tests (Stroop and Trail-Making-Test [TMT]) and EEG were performed before and after single-session stimulation. Gamma-tACS improved the Stroop-color in comparison with tDCS (p = .044) and sham (p = .010) and enhanced the TMT-B in comparison with sham (p = .021). However, tDCS was not significantly different from sham in changes of any cognitive test scores. In EEG analysis, gamma-tACS increased beta activity in comparison with sham and tDCS, whereas tDCS decreased delta and theta activity in comparison with sham. Gamma-tACS also increased beta 2 source activity in the anterior cingulate, compared to sham. The cognitive benefits of tACS in MCI patients appeared superior to those of tDCS. tACS facilitated cognitive function by increasing beta activity, while tDCS delayed the progression of MCI symptoms by decreasing slow-frequency activity. Thus, tACS could be used as a new therapeutic option for MCI.


Asunto(s)
Disfunción Cognitiva , Estimulación Transcraneal de Corriente Directa , Cognición , Disfunción Cognitiva/terapia , Humanos , Pruebas Neuropsicológicas , Corteza Prefrontal
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