Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 38
Filtrar
Más filtros

Banco de datos
Tipo del documento
País de afiliación
Intervalo de año de publicación
1.
Small ; 20(22): e2310036, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-38126916

RESUMEN

Strain effect in the structurally defective materials can contribute to the catalysis optimization. However, it is challenging to achieve the performance improvement by strain modulation with the help of geometrical structure because strain is spatially dependent. Here, a new class of compressively strained platinum-iridium-metal zigzag-like nanowires (PtIrM ZNWs, M = nickel (Ni), cobalt (Co), iron (Fe), zinc (Zn) and gallium (Ga)) is reported as the efficient alkaline hydrogen evolution reaction (HER) and hydrogen oxidation reaction (HOR) catalysts. Particularly, the optimized PtIrNi ZNWs with 3% compressive strain (cs-PtIrNi ZNWs) can achieve the highest HER/HOR performances among all the catalysts investigate. Their HOR mass and specific activities are 3.2/14.4 and 2.6/32.7 times larger than those of PtIrNi NWs and commercial Pt/C, respectively. Simultaneously, they can exhibit the superior stability and high CO resistance for HOR. Further, experimental and theoretical studies collectively reveal that the compressive strain in cs-PtIrNi ZNWs effectively weakens the adsorption of hydroxyl intermediate and modulates the electronic structure, resulting in the weakened hydrogen binding energy (HBE) and moderate hydroxide binding energy (OHBE), beneficial for the improvement of HOR performance. This work highlights the importance of strain tuning in enhancing Pt-based nanomaterials for hydrogen catalysis and beyond.

2.
J Neurosci Res ; 101(6): 916-929, 2023 06.
Artículo en Inglés | MEDLINE | ID: mdl-36696411

RESUMEN

Deep brain stimulation (DBS) of the anterior nucleus of the thalamus (ANT) appears to be effective against seizures in animals and humans however, its therapeutic mechanisms remain elusive. This study aimed to combine 9.4T multimodal magnetic resonance imaging (MRI) with histology to investigate the longitudinal effects of long-term ANT-DBS in pilocarpine-induced epileptic rats. Status epilepsy (SE) was induced by LiCl-pilocarpine injection in 11 adult male Sprague-Dawley rats. Four weeks after SE, chronic epileptic rats underwent either ANT-DBS (n = 6) or sham-DBS (n = 5) surgery. Electroencephalography (EEG) and spontaneous recurrent seizures (SRS) were recorded for 1 week. The T2-weighted image and images from resting-state functional MRI (rs-fMRI) were acquired at three states: before SE, at 4 weeks post-SE, and at 5 weeks post-DBS. Volumes of the hippocampal subregions and hippocampal-related functional connectivity (FC) were compared longitudinally. Finally, antibodies against neuronal nuclei (NeuN) and glial fibrillary acidic proteins were used to evaluate neuronal loss and astrogliosis in the hippocampus. Long-term ANT-DBS significantly reduced seizure generalization in pilocarpine-induced epileptic rats. By analyzing the gray matter volume using T2-weighted images, long-term ANT-DBS displayed morphometric restoration of the hippocampal subregions. Neuronal protection of the hippocampal subregions and inhibition of astrogliosis in the hippocampal subregions were observed in the ANT-DBS group. ANT-DBS caused reversible regulation of FC in the insula-hippocampus and subthalamic nucleus-hippocampus. Long-term ANT-DBS provides comprehensive protection of hippocampal histology, hippocampal morphometrics, and hippocampal-related functional networks.


Asunto(s)
Estimulación Encefálica Profunda , Epilepsia , Humanos , Adulto , Ratas , Masculino , Animales , Pilocarpina/toxicidad , Pilocarpina/metabolismo , Gliosis/inducido químicamente , Gliosis/diagnóstico por imagen , Gliosis/metabolismo , Ratas Sprague-Dawley , Estimulación Encefálica Profunda/métodos , Epilepsia/inducido químicamente , Epilepsia/diagnóstico por imagen , Epilepsia/terapia , Convulsiones/metabolismo , Imagen por Resonancia Magnética , Hipocampo/metabolismo
3.
Neuropathol Appl Neurobiol ; 49(4): e12926, 2023 08.
Artículo en Inglés | MEDLINE | ID: mdl-37483117

RESUMEN

AIMS: Mesial temporal lobe epilepsy without hippocampal sclerosis (no-HS MTLE) refers to those MTLE patients who have neither magnetic resonance imaging (MRI) lesions nor definite pathological evidence of hippocampal sclerosis. They usually have resistance to antiepileptic drugs, difficulties in precise seizure location and poor surgical outcomes. Adenosine is a neuroprotective neuromodulator that acts as a seizure terminator in the brain. The role of adenosine in no-HS MTLE is still unclear. Further research to explore the aetiology and pathogenesis of no-HS MTLE may help to find new therapeutic targets. METHODS: In surgically resected hippocampal specimens, we examined the maladaptive changes of the adenosine system of patients with no-HS MTLE. In order to better understand the dysregulation of the adenosine pathway in no-HS MTLE, we developed a rat model based on the induction of focal cortical lesions through a prenatal freeze injury. RESULTS: We first examined the adenosine system in no-HS MTLE patients who lack hippocampal neuronal loss and found ectopic expression of the astrocytic adenosine metabolising enzyme adenosine kinase (ADK) in hippocampal pyramidal neurons, as well as downregulation of neuronal A1 receptors (A1 Rs) in the hippocampus. In the no-HS MTLE model rats, the transition of ADK from neuronal expression to an adult pattern of glial expression in the hippocampus was significantly delayed. CONCLUSIONS: Ectopic expression of neuronal ADK might be a pathological hallmark of no-HS MTLE. Maladaptive changes in adenosine metabolism might be a novel target for therapeutic intervention in no-HS MTLE.


Asunto(s)
Epilepsia del Lóbulo Temporal , Esclerosis del Hipocampo , Animales , Ratas , Epilepsia del Lóbulo Temporal/patología , Adenosina Quinasa/metabolismo , Expresión Génica Ectópica , Convulsiones/patología , Imagen por Resonancia Magnética , Hipocampo/patología , Biomarcadores/metabolismo , Esclerosis/patología
4.
J Neuroinflammation ; 19(1): 70, 2022 Mar 26.
Artículo en Inglés | MEDLINE | ID: mdl-35337341

RESUMEN

BACKGROUND: The etiology of Rasmussen's encephalitis (RE), a rare chronic neurological disorder characterized by CD8+ T cell infiltration and unihemispheric brain atrophy, is still unknown. Various human herpes viruses (HHVs) have been detected in RE brain, but their contribution to RE pathogenesis is unclear. METHODS: HHVs infection and relevant immune response were compared among brain tissues from RE, temporal lobe epilepsy (TLE) and traumatic brain injury (TBI) patients. Viral antigen or genome, CD8+ T cells, microglia and innate immunity molecules were analyzed by immunohistochemical staining, DNA dot blot assay or immunofluorescence double staining. Cytokines were measured by multiplex flow cytometry. Cell apoptosis was visualized by TUNEL staining. Viral infection, immune response and the severity of unihemispheric atrophy were subjected to correlation analysis. RESULTS: Antigens of various HHVs were prevalent in RE and TLE brains, and the cumulative viral score of HHVs positively correlated with the unihemispheric atrophy in RE patients. CD8+ T cells infiltration were observed in both RE and TLE brains and showed co-localization with HHV antigens, but their activation, as revealed by Granzyme B (GZMB) release and apoptosis, was found only in RE. In comparison to TLE, RE brain tissues contained higher level of inflammatory cytokines, but the interferon-ß level, which was negatively correlated with cumulative viral score, was relatively lower. In line with this, the DNA sensor STING and IFI16, rather than other innate immunity signaling molecules, were insufficiently activated in RE. CONCLUSIONS: Compared with TBI, both RE and TLE had prevalently HHV infection and immune response in brain tissues. However, in comparison to TLE, RE showed insufficient activation of antiviral innate immunity but overactivation of cytotoxic T cells. Our results show the relatively lower level of antiviral innate immunity and overactivation of cytotoxic T cells in RE cases upon HHV infection, the overactivated T cells might be a compensate to the innate immunity but the causative evidence is lack in our study and need more investigation in the future.


Asunto(s)
Encefalitis , Epilepsia del Lóbulo Temporal , Virus , Encéfalo/metabolismo , Encefalitis/patología , Epilepsia del Lóbulo Temporal/patología , Humanos , Interferón beta , Virus/metabolismo
5.
Acta Neurol Scand ; 146(6): 761-766, 2022 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-36189924

RESUMEN

Rasmussen's encephalitis (RE) is a rare condition of unknown etiology that causes a severe chronically neurological disorder with mostly affecting children. The main clinical feature of RE includes frequent seizures with drug-resistant, unilateral hemispheric atrophy, and progressive neurological deficits. In this review, we summarized five pathogenesis on the basis of the current research including virus infection, antibody-mediated degeneration, cell-mediated immunity, microglia-induced degeneration, and genetic mutations. So far, no exact virus in RE brain tissue or definite antigen in humoral immune system was confirmed as the determined etiology. The importance of cytotoxic CD8+ T lymphocytes and activated microglial and the role of their immune mechanism in RE development are gradually emerging with the deep study. Genetic researches support the notion that the pathogenesis of RE is probably associated with single nucleotide polymorphisms on immune-related genes, which is driven by affecting inherent antiretroviral innate immunity. Recent advances in treatment suggest immunotherapy could partially slows down the progression of RE according to the histopathology and clinical presentation, which aimed at the initial damage to the brain by T cells and microglia in the early stage. However, the cerebral hemispherectomy is an effective means to controlling the intractable seizure, which is accompanied by neurological complications inevitably. So, the optimal timing for surgical intervention is still a challenge for RE patient. On the contrary, exploration on other aspects of pathogenesis such as dysfunction of adenosine system may offer a new therapeutic option for the treatment of RE in future.


Asunto(s)
Encefalitis , Hemisferectomía , Niño , Humanos , Encefalitis/etiología , Encefalitis/terapia , Encéfalo , Convulsiones , Atrofia/patología
6.
Angew Chem Int Ed Engl ; 61(44): e202212780, 2022 Nov 02.
Artículo en Inglés | MEDLINE | ID: mdl-36082987

RESUMEN

Designing water-deficient solvation sheath of Zn2+ by ligand substitution is a widely used strategy to protect Zn metal anode, yet the intrinsic tradeoff between Zn nucleation/dissolution kinetics and the side hydrogen evolution reaction (HER) remains a huge challenge. Herein, we find boric acid (BA) with moderate ligand field interaction can partially replace H2 O molecules in the solvation sheath of Zn2+ , forming a stable water-deficient solvation sheath. It enables fast Zn nucleation/dissolution kinetics and substantially suppressed HER. Crucially, by systematically comparing the ligand field strength and solvation energies between BA and the ever-reported electrolyte additives, we also find that the solvation energy has a strong correlation with Zn nucleation/dissolution kinetics and HER inhibition ability, displaying a classic volcano behavior. The modulation map could provide valuable insights for solvation sheath design of zinc batteries and beyond.

7.
Epilepsy Behav ; 121(Pt A): 108045, 2021 08.
Artículo en Inglés | MEDLINE | ID: mdl-34116339

RESUMEN

Epilepsy with comorbid depression has recently attracted increasing attention. Temporal lobe epilepsy (TLE) may represent an increased risk of developing depression, especially if the seizures do not generalize. The two-pore domain potassium channel-TWIK-related K+ channel (TREK-1) plays important roles in both epilepsy and depression. However, the changes in its expression in patients with epilepsy with comorbid depression remain unclear. In the present study, we analyzed depressive symptoms using neuropsychiatric scales in forty-two patients with drug-resistant TLE, who also underwent EEG in waking and sleeping states, as well as 3.0 T brain MRI. We tested for TREK-1 positive neurons and microglial cells in the anterior hippocampi of patients with drug-resistant TLE with and without comorbid depression (n=5/group). Approximately 31% of patients with TLE had comorbid depression (13/42). Meanwhile, the patients who had hippocampal sclerosis had much higher scores on the depression rating scale. The results indicated the contribution of hippocampal sclerosis to the development of depression. Immunostaining of TREK-1 channels was observed in neurons and glia in the anterior hippocampus. Increased immunoreactivity of TREK-1 neurons was observed in the hippocampi of patients with TLE with comorbid depression compared with nondepressed patients with TLE. TREK-1 was expressed in almost all microglia. Curiously, more activated TREK-1-positive microglia were observed in patients with TLE with depression than in those without depression. The results suggested that a change in TREK-1 immunoreactivity was involved, at least partly, in the development of depression as a comorbidity of TLE. Imbalance of the TREK-1 channel may be a potential target for the treatment of patients with epilepsy with comorbid depression.


Asunto(s)
Epilepsia Refractaria , Epilepsia del Lóbulo Temporal , Depresión/epidemiología , Epilepsia Refractaria/complicaciones , Epilepsia Refractaria/epidemiología , Epilepsia del Lóbulo Temporal/complicaciones , Epilepsia del Lóbulo Temporal/epidemiología , Hipocampo , Humanos , Neuronas
8.
Nano Lett ; 19(2): 1336-1342, 2019 02 13.
Artículo en Inglés | MEDLINE | ID: mdl-30629451

RESUMEN

While surface strain engineering in shaped and bimetallic nanostructures offers additional variables for manoeuvring the catalysis, manipulating isotropic strain distributions in nanostructures remains a great challenge to reach higher tiers of the catalyst's design. Herein, we report an efficient approach to construct a unique class of core/shell palladium-lead (Pd-Pb)/Pd nanosheets (NSs) and nanocubes (NCs) with homogeneous tensile strain along [001] on both the top-Pd and edge-Pd surfaces for boosting oxygen reduction reaction (ORR). These core/shell Pd-Pb/Pd NSs and Pd-Pb/Pd NCs exhibit over 160% and 140% increases in mass activity and over 114% and 98% increases in specific activity when compared with these unshelled counterparts, respectively. Especially, the Pd3Pb/Pd NSs show the ORR mass and specific activities of 0.57 A/mgPd and 1.31 mA/cm2 at 0.90 V versus reversible hydrogen electrode, which are 8.8 (6.5) and 9.4 (9.8) times higher than those of the commercial Pd/C (Pt/C), respectively. The valence band photoemission spectra and first-principles calculations collectively show that the tensile strained Pd shell results in an upshift of the d-band-center of Pd, weakening the chemisorption of oxygenated species due to the contribution of the antibonding orbital. In addition, the Pd3Pb/Pd NSs and NCs with intermetallic core and homogeneous few layers of Pd shell can sustain at least 20 000 potential cycles with negligible activity decay and composition changes. The present work provides a new direction for the design of highly active and stable catalysts for fuel cells and beyond.

9.
Angew Chem Int Ed Engl ; 59(17): 6929-6935, 2020 Apr 20.
Artículo en Inglés | MEDLINE | ID: mdl-32100367

RESUMEN

Despite the fact that many strategies have been developed to improve the efficiency of the oxygen evolution reaction (OER), the precise modulation of the surface electronic properties of catalysts to improve their catalytic activity is still challenging. Herein, we demonstrate that the surface active electron density of Co3 O4 can be effectively regulated by an argon-ion irradiation method. X-ray photoelectron and synchrotron x-ray absorption spectroscopy, UV photoelectron spectrometry, and DFT calculations show that the surface active electron density band center of Co3 O4 has been upshifted, leading to a significantly enhanced absorption capability of the oxo group. The optimized Co3 O4 -based catalysts exhibit an excellent overpotential of 260 mV at 10 mA cm-2 and Tafel slope of 54 mV dec-1 , superior to the capability of the benchmark RuO2 , representing one of the best Co-based OER catalysts. This approach could guide the future rational design and discovery of ideal electrocatalysts.

10.
Cell Mol Neurobiol ; 39(3): 461-470, 2019 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-30790096

RESUMEN

Temporal lobe epilepsy (TLE) is associated with neurodegeneration, often leading to hippocampal sclerosis (HS). Type 1 HS, which is characterized by severe neuronal loss and gliosis predominantly in regions CA1 and CA4, is the most common subtype and is associated with the best prognosis according to the ILAE classification system. MiRNAs participate in the biological processes underlying many nervous system diseases, including epilepsy. However, the miRNA expression profile of HS ILAE type 1 is not completely understood. A total of 14 patients were identified as having the ILAE subtype, as determined by NeuN immunohistochemistry (ILAE type 1 = 7; no-HS = 7). Next-generation sequencing and reverse transcription polymerase chain reaction technology were used to validate the dysregulated miRNAs. Bioinformatics analysis of the predicted target genes was conducted using Gene Ontology and Kyoto Encyclopedia of Genes and Genomes analyses. In total, 1643 mature miRNAs were detected in this study, along with 5 miRNAs that were upregulated and 2 miRNAs that were downregulated in the type 1 group. Bioinformatics analysis showed that 1545 target genes were predicted using the miRDB and Targetscan databases and that these predicted genes showed enrichment in pathways associated with nucleic acid binding, intracellular and cellular macromolecule metabolic processes, and the PI3K-Akt signaling pathway. This study is the first to report the miRNA expression profile of HS ILAE type 1 compared with those of no-HS. These results provide new insights into the neuronal loss pathology of type 1 HS.


Asunto(s)
Epilepsia del Lóbulo Temporal/genética , Perfilación de la Expresión Génica , Hipocampo/patología , MicroARNs/genética , Adolescente , Adulto , Estudios de Casos y Controles , Niño , Biología Computacional , Femenino , Humanos , Masculino , MicroARNs/metabolismo , Reproducibilidad de los Resultados , Esclerosis , Adulto Joven
11.
Angew Chem Int Ed Engl ; 58(46): 16660-16667, 2019 Nov 11.
Artículo en Inglés | MEDLINE | ID: mdl-31489768

RESUMEN

An N-doped TiO2 model reveals a conceptually different mechanism for activating the N dopant based on delocalized orbital hybridization through O vacancy incorporation. Synchrotron-based X-ray absorption spectroscopy, time-resolved fluorescence, and DFT studies revealed that O vacancy incorporation can effectively stimulate the delocalization of N impurity states through p-band orbital modulation, which leads to a significant enhancement in photocarrier lifetime. Consequently, this effect also results in a remarkable increase in the incident photon-to-electron conversion efficiency in the range of 400-550 nm compared to that of conventional N-incorporated TiO2 (15 % versus 1 % at 450 nm). This work reveals the fundamental necessity of orbital modulation in the band engineering of metal oxides for driving solar water splitting and beyond.

12.
Seizure ; 120: 124-134, 2024 Jun 29.
Artículo en Inglés | MEDLINE | ID: mdl-38959583

RESUMEN

OBJECTIVE: To summarize the surgical outcomes of genetically refractory epilepsy and identify prognostic factors for these outcomes. METHODS: A literature search of the PubMed, Web of Science, and Embase databases for relevant studies, published between January 1, 2002 and December 31, 2023, was performed using specific search terms. All studies addressing surgical outcomes and follow-up of genetically refractory epilepsy were included. All statistical analyses were performed using STATA software (StataCorp LLC, College Station, TX, USA). This review was performed in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses, 2020 (i.e., "PRISMA") reporting guidelines. RESULTS: Of the 3833 studies retrieved, 55 fulfilled the inclusion criteria. Eight studies were eligible for meta-analysis at the study level. Pooled outcomes revealed that 74 % of patients who underwent resective surgery (95 % confidence interval [CI] 0.55-0.89; z = 9.47, p < 0.05) achieved Engel I status at the last follow-up. In the study level analysis, pooled outcomes revealed that 9 % of patients who underwent vagus nerve stimulation achieved seizure-free status (95 % CI 0.00-0.31; z = 1.74, p < 0.05), and 61 % (95 % CI 0.55-0.89; z = 11.96, p < 0.05) achieved a 50 % reduction in seizure frequency at the last follow-up. Fifty-three studies comprising 249 patients were included in an individual-level analysis. Among patients who underwent lesion resection or lobectomy/multilobar resection, 65 % (100/153) achieved Engel I status at the last follow-up. Univariate analysis indicated that female sex, somatic mutations, and presenting with focal seizure symptoms were associated with better prognosis (p < 0.05). Additionally, 75 % (21/28) of patients who underwent hemispherectomy/hemispherotomy achieved Engel I status at the last follow-up. In the individual-level analysis, among patients treated with vagus nerve stimulation, 21 % (10/47) were seizure-free and 64 % (30/47) experienced >50 % reduction in seizure frequency compared with baseline. CONCLUSION: Meticulous presurgical evaluation and selection of appropriate surgical procedures can, to a certain extent, effectively control seizures. Therefore, various surgical procedures should be considered when treating patients with genetically refractory epilepsy.

13.
Nat Commun ; 15(1): 3233, 2024 Apr 15.
Artículo en Inglés | MEDLINE | ID: mdl-38622140

RESUMEN

Electrochemical hydrogenation of acetonitrile based on well-developed proton exchange membrane electrolyzers holds great promise for practical production of ethylamine. However, the local acidic condition of proton exchange membrane results in severe competitive proton reduction reaction and poor selection toward acetonitrile hydrogenation. Herein, we conduct a systematic study to screen various metallic catalysts and discover Pd/C exhibits a 43.8% ethylamine Faradaic efficiency at the current density of 200 mA cm-2 with a specific production rate of 2912.5 mmol g-1 h-1, which is about an order of magnitude higher than the other screened metal catalysts. Operando characterizations indicate the in-situ formed PdHx is the active centers for catalytic reaction and the adsorption strength of the *MeCH2NH2 intermediate dictates the catalytic selectivity. More importantly, the theoretical analysis reveals a classic d-band mediated volcano curve to describe the relation between the electronic structures of catalysts and activity, which could provide valuable insights for designing more effective catalysts for electrochemical hydrogenation reactions and beyond.

14.
Virol Sin ; 39(2): 251-263, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38219860

RESUMEN

Viral encephalitis continues to be a significant public health concern. In our previous study, we discovered a lower expression of antiviral factors, such as IFN-ß, STING and IFI16, in the brain tissues of patients with Rasmussen's encephalitis (RE), a rare chronic neurological disorder often occurred in children, characterized by unihemispheric brain atrophy. Furthermore, a higher cumulative viral score of human herpes viruses (HHVs) was also found to have a significant positive correlation with the unihemispheric atrophy in RE. Type I IFNs (IFN-I) signaling is essential for innate anti-infection response by binding to IFN-α/ß receptor (IFNAR). In this study, we infected WT mice and IFNAR-deficient A6 mice with herpes simplex virus 1 (HSV-1) via periocular injection to investigate the relationship between IFN-I signaling and HHVs-induced brain lesions. While all mice exhibited typical viral encephalitis lesions in their brains, HSV-induced epilepsy was only observed in A6 mice. The gene expression matrix, functional enrichment analysis and protein-protein interaction network revealed four gene models that were positively related with HSV-induced epilepsy. Additionally, ten key genes with the highest scores were identified. Taken together, these findings indicate that intact IFN-I signaling can effectively limit HHVs induced neural symptoms and brain lesions, thereby confirming the positive correlation between IFN-I signaling repression and brain atrophy in RE and other HHVs encephalitis.


Asunto(s)
Epilepsia , Herpes Simple , Herpesvirus Humano 1 , Interferón Tipo I , Transducción de Señal , Animales , Femenino , Ratones , Encéfalo/patología , Encéfalo/virología , Modelos Animales de Enfermedad , Encefalitis por Herpes Simple/virología , Encefalitis por Herpes Simple/inmunología , Encefalitis por Herpes Simple/patología , Epilepsia/virología , Epilepsia/patología , Herpes Simple/virología , Herpes Simple/patología , Herpes Simple/inmunología , Herpesvirus Humano 1/patogenicidad , Herpesvirus Humano 1/inmunología , Interferón Tipo I/metabolismo , Interferón Tipo I/inmunología , Ratones Endogámicos C57BL , Ratones Noqueados , Mapas de Interacción de Proteínas , Receptor de Interferón alfa y beta/genética , Receptor de Interferón alfa y beta/deficiencia
15.
Nat Commun ; 15(1): 1614, 2024 Feb 22.
Artículo en Inglés | MEDLINE | ID: mdl-38388525

RESUMEN

While Ru owns superior catalytic activity toward hydrogen oxidation reaction and cost advantages, the catalyst deactivation under high anodic potential range severely limits its potential to replace the Pt benchmark catalyst. Unveiling the deactivation mechanism of Ru and correspondingly developing protection strategies remain a great challenge. Herein, we develop atomic Pt-functioned Ru nanoparticles with excellent anti-deactivation feature and meanwhile employ advanced operando characterization tools to probe the underlying roles of Pt in the anti-deactivation. Our studies reveal the introduced Pt single atoms effectively prevent Ru from oxidative passivation and consequently preserve the interfacial water network for the critical H* oxidative release during catalysis. Clearly understanding the deactivation nature of Ru and Pt-induced anti-deactivation under atomic levels could provide valuable insights for rationally designing stable Ru-based catalysts for hydrogen oxidation reaction and beyond.

16.
ACS Nano ; 17(18): 17779-17789, 2023 Sep 26.
Artículo en Inglés | MEDLINE | ID: mdl-37708057

RESUMEN

The development of high-performance platinum (Pt)-based electrocatalysts for the hydrogen oxidation reaction (HOR) is highly desirable for hydrogen fuel cells, but it is limited by the sluggish kinetics and severe carbon monoxide (CO) poisoning in alkaline medium. Herein, we explore a class of facet-selected Pt-nickel-indium fishbone-like nanowires (PtNiIn FNWs) featuring high-index facets (HIFs) of Pt3In skin as efficient alkaline HOR catalysts. Impressively, the optimized Pt66Ni6In28 FNWs show the highest mass and specific activities of 4.02 A mgPt-1 and 6.56 mA cm-2, 2.0/2.1 and 13.9/15.6 times larger than those of commercial PtRu/C and commercial Pt/C, respectively, along with a competitive CO-tolerance ability. Specifically, they exhibit only 6.0% current density decay after 10000 s of operation and 25.7% activity loss after 2000 s in the presence of 1000 ppm of CO. Moreover, an isotope experiment and density functional theory (DFT) calculations further prove that the unique structure and synergy among Pt, Ni, and In endow these Pt66Ni6In28 FNWs with an optimized hydrogen binding energy (HBE) and an advantageous hydroxide binding energy (OHBE), giving them excellent alkaline HOR properties. The combined construction of surface-skin and HIFs in PtNiIn FNWs will offer an available method to realize the potential applications of advanced non-PtRu-based catalysts in fuel cells and beyond.

17.
Nat Commun ; 14(1): 3847, 2023 Jun 29.
Artículo en Inglés | MEDLINE | ID: mdl-37386000

RESUMEN

Copper is well-known to be selective to primary amines via electrocatalytic nitriles hydrogenation. However, the correlation between the local fine structure and catalytic selectivity is still illusive. Herein, we find that residual lattice oxygen in oxide-derived Cu nanowires (OD-Cu NWs) plays vital roles in boosting the acetonitrile electroreduction efficiency. Especially at high current densities of more than 1.0 A cm-2, OD-Cu NWs exhibit relatively high Faradic efficiency. Meanwhile, a series of advanced in situ characterizations and theoretical calculations uncover that oxygen residues, in the form of Cu4-O configuration, act as electron acceptors to confine the free electron flow on the Cu surface, consequently improving the kinetics of nitriles hydrogenation catalysis. This work could provide new opportunities to further improve the hydrogenation performance of nitriles and beyond, by employing lattice oxygen-mediated electron tuning engineering.


Asunto(s)
Cobre , Electrones , Hidrogenación , Acetonitrilos , Nitrilos , Catálisis , Óxidos , Oxígeno
18.
CNS Neurosci Ther ; 29(9): 2597-2607, 2023 09.
Artículo en Inglés | MEDLINE | ID: mdl-37017409

RESUMEN

AIMS: Deep brain stimulation (DBS) of the anterior nucleus of the thalamus, is an effective therapy for patients with drug-resistant epilepsy, yet, its mechanism of action remains elusive. Adenosine kinase (ADK), a key negative regulator of adenosine, is a potential modulator of epileptogenesis. DBS has been shown to increase adenosine levels, which may suppress seizures via A1 receptors (A1 Rs). We investigated whether DBS could halt disease progression and the potential involvement of adenosine mechanisms. METHODS: Control group, SE (status epilepticus) group, SE-DBS group, and SE-sham-DBS group were included in this study. One week after a pilocarpine-induced status epilepticus, rats in the SE-DBS group were treated with DBS for 4 weeks. The rats were monitored by video-EEG. ADK and A1 Rs were tested with histochemistry and western blot, respectively. RESULTS: Compared with the SE group and SE-sham-DBS group, DBS could reduce the frequency of spontaneous recurrent seizures (SRS) and the number of interictal epileptic discharges. The DPCPX, an A1 R antagonist, reversed the effect of DBS on interictal epileptic discharges. In addition, DBS inhibited the overexpression of ADK and the downregulation of A1 Rs. CONCLUSION: The findings indicate that DBS can reduce SRS in epileptic rats via inhibition of ADK and activation of A1 Rs. A1 Rs might be a potential target of DBS for the treatment of epilepsy.


Asunto(s)
Adenosina Quinasa , Epilepsia , Receptor de Adenosina A1 , Convulsiones , Estado Epiléptico , Animales , Ratas , Receptor de Adenosina A1/metabolismo , Adenosina Quinasa/metabolismo , Epilepsia/inducido químicamente , Epilepsia/terapia , Convulsiones/inducido químicamente , Convulsiones/terapia , Estado Epiléptico/inducido químicamente , Estado Epiléptico/terapia , Pilocarpina , Masculino , Ratas Sprague-Dawley , Progresión de la Enfermedad
19.
Mol Neurobiol ; 60(8): 4396-4417, 2023 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-37103687

RESUMEN

Focal cortical dysplasia (FCD), a common malformation of cortical development, is frequently associated with pharmacoresistant epilepsy in both children and adults. Adenosine is an inhibitory modulator of brain activity and a prospective anti-seizure agent with potential for clinical translation. Our previous results demonstrated that the major adenosine-metabolizing enzyme adenosine kinase (ADK) was upregulated in balloon cells (BCs) within FCD type IIB lesions, suggesting that dysfunction of the adenosine system is implicated in the pathophysiology of FCD. In our current study, we therefore performed a comprehensive analysis of adenosine signaling in surgically resected cortical specimens from patients with FCD type I and type II via immunohistochemistry and immunoblot analysis. Adenosine enzyme signaling was assessed by quantifying the levels of the key enzymes of adenosine metabolism, i.e., ADK, adenosine deaminase (ADA), and ecto-5'-nucleotidase (CD73). Adenosine receptor signaling was assessed by quantifying the levels of adenosine A2A receptor (A2AR) and putative downstream mediators of adenosine, namely, glutamate transporter-1 (GLT-1) and mammalian target of rapamycin (mTOR). Within lesions in FCD specimens, we found that the adenosine-metabolizing enzymes ADK and ADA, as well as the adenosine-producing enzyme CD73, were upregulated. We also observed an increase in A2AR density, as well as a decrease in GLT-1 levels and an increase in mTOR levels, in FCD specimens compared with control tissue. These results suggest that dysregulation of the adenosine system is a common pathologic feature of both FCD type I and type II. The adenosine system might therefore be a therapeutic target for the treatment of epilepsy associated with FCD.


Asunto(s)
Epilepsia , Displasia Cortical Focal , Malformaciones del Desarrollo Cortical de Grupo I , Malformaciones del Desarrollo Cortical , Niño , Adulto , Humanos , Epilepsia/patología , Malformaciones del Desarrollo Cortical de Grupo I/metabolismo , Malformaciones del Desarrollo Cortical de Grupo I/patología , Transducción de Señal , Serina-Treonina Quinasas TOR/metabolismo
20.
Neuroimage Clin ; 33: 102918, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-34952352

RESUMEN

Volumetric magnetic resonance imaging (MRI) atrophy is a hallmark of Rasmussen's encephalitis (RE). Here, we aim to investigate voxel-wise gray matter (GM) atrophy in RE, and its associations with glucose hypometabolism and neurotransmitter distribution utilizing MRI and PET data. In this study, fifteen RE patients and fourteen MRI normal subjects were included in this study. Voxel-wise GM volume and glucose metabolic uptake were evaluated using structural MRI and FDG-PET images, respectively. Spatial Spearman's correlation was performed between GM atrophy of RE with FDG uptake alterations, and neurotransmitter distributions provided in the JuSpace toolbox. Compared with the control group, RE patients displayed extensive GM volume loss not only in the ipsilateral hemisphere, but also in the frontal lobe, basal ganglia, and cerebellum in the contralateral hemisphere. Within the RE group, the insular and temporal cortices exhibited significantly more GM atrophy on the ipsilesional than the contralesional side. FDG-PET data revealed significant hypometabolism in areas surrounding the insular cortices in the ipsilesional hemisphere. RE-related GM volumetric atrophy was spatially correlated with hypomebolism in FDG uptake, and with spatial distribution of the dopaminergic and serotonergic neurotransmitter systems. The spatial concordance of morphological changes with metabolic abnormalities suggest FDG-PET offers potential value for RE diagnosis. The GM alterations associated with neurotransmitter distribution map could provide novel insight in understanding the neuropathological mechanisms and clinical feature of RE.


Asunto(s)
Encefalitis , Imagen por Resonancia Magnética , Atrofia/patología , Encefalitis/diagnóstico por imagen , Encefalitis/patología , Sustancia Gris/diagnóstico por imagen , Sustancia Gris/patología , Humanos , Imagen por Resonancia Magnética/métodos , Metaboloma
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA