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1.
Nature ; 619(7968): 73-77, 2023 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-37316660

RESUMEN

High-entropy alloy nanoparticles (HEA-NPs) show great potential as functional materials1-3. However, thus far, the realized high-entropy alloys have been restricted to palettes of similar elements, which greatly hinders the material design, property optimization and mechanistic exploration for different applications4,5. Herein, we discovered that liquid metal endowing negative mixing enthalpy with other elements could provide a stable thermodynamic condition and act as a desirable dynamic mixing reservoir, thus realizing the synthesis of HEA-NPs with a diverse range of metal elements in mild reaction conditions. The involved elements have a wide range of atomic radii (1.24-1.97 Å) and melting points (303-3,683 K). We also realized the precisely fabricated structures of nanoparticles via mixing enthalpy tuning. Moreover, the real-time conversion process (that is, from liquid metal to crystalline HEA-NPs) is captured in situ, which confirmed a dynamic fission-fusion behaviour during the alloying process.

2.
FASEB J ; 38(13): e23767, 2024 Jul 15.
Artículo en Inglés | MEDLINE | ID: mdl-38924166

RESUMEN

Macrophages possess a diverse range of well-defined capabilities and roles as phagocytes, encompassing the regulation of inflammation, facilitation of wound healing, maintenance of tissue homeostasis, and serving as a crucial element in the innate immune response against microbial pathogens. The emergence of extracellular traps is a novel strategy of defense that has been observed in several types of innate immune cells. In response to infection, macrophages are stimulated and produce macrophage extracellular traps (METs), which take the form of net-like structures, filled with strands of DNA and adorned with histones and other cellular proteins. METs not only capture and eliminate microorganisms but also play a role in the development of certain diseases such as inflammation and autoimmune disorders. The primary objective of this study is to examine the latest advancements in METs for tackling bacterial infections. We also delve into the current knowledge and tactics utilized by bacteria to elude or endure the effects of METs. Through this investigation, we hope to shed light on the intricate interactions between bacteria and the host's immune system, particularly in the context of microbicidal effector mechanisms of METs. The continued exploration of METs and their impact on host defense against various pathogens opens up new avenues for understanding and potentially manipulating the immune system's response to infections.


Asunto(s)
Infecciones Bacterianas , Trampas Extracelulares , Macrófagos , Trampas Extracelulares/inmunología , Trampas Extracelulares/metabolismo , Humanos , Macrófagos/inmunología , Macrófagos/microbiología , Infecciones Bacterianas/inmunología , Infecciones Bacterianas/microbiología , Animales , Inmunidad Innata
3.
Clin Immunol ; 265: 110291, 2024 Jun 20.
Artículo en Inglés | MEDLINE | ID: mdl-38908771

RESUMEN

Linear IgA bullous dermatosis (LABD) and dermatitis herpetiformis (DH) represent the major subtypes of IgA mediated autoimmune bullous disorders. We sought to understand the disease etiology by using serum proteomics. We assessed 92 organ damage biomarkers in LAB, DH, and healthy controls using the Olink high-throughput proteomics. The positive proteomic serum biomarkers were used to correlate with clinical features and HLA type. Targeted proteomic analysis of IgA deposition bullous disorders vs. controls showed elevated biomarkers. Further clustering and enrichment analyses identified distinct clusters between LABD and DH, highlighting the involvement of nicotinamide adenine dinucleotide phosphate (NADPH) oxidase. Comparative analysis revealed biomarkers with distinction between LABD and DH and validated in the skin lesion. Finally, qualitative correlation analysis with DEPs suggested six biomarkers (NBN, NCF2, CAPG, FES, BID, and PXN) have better prognosis in DH patients. These findings provide potential biomarkers to differentiate the disease subtype of IgA deposition bullous disease.

4.
Radiology ; 311(3): e232274, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38888481

RESUMEN

Background The role of perivascular space (PVS) dysfunction in obstructive sleep apnea (OSA) requires further study. Purpose To compare MRI indexes of PVS across patients with differing severities of OSA and relate them with disease characteristics and treatment. Materials and Methods This single-center prospective study included healthy controls (HCs) and patients with complaints of snoring who underwent MRI and cognitive evaluation between June 2021 and December 2022. Participants with complaints of snoring were classified into four groups (snoring, mild OSA, moderate OSA, and severe OSA). PVS networks were assessed at MRI using PVS volume fraction, extracellular free water (FW), and diffusion tensor imaging analysis along the PVS (DTI-ALPS). One-way analysis of variance and Pearson correlation were used for analysis. Alterations in PVS indexes and cognitive performance after treatment were assessed in 15 participants with moderate OSA. Results A total of 105 participants (mean age, 33.4 years ± 8.9 [SD]; 80 males) and 50 HCs (mean age, 37.0 years ± 8.6; 33 males) were included. Higher mean PVS volume fraction was observed in participants with severe OSA (n = 23) than in patients with mild OSA (n = 36) (0.11 vs 0.10; P = .03). Participants with severe OSA exhibited higher mean FW index (0.11) than both HCs (0.10; P < .001) and patients with mild OSA (0.10; P = .003). All patient groups had lower DTI-ALPS than HCs (range, 1.5-1.9 vs 2.1; all P < .001). DTI-ALPS correlated with cognitive performance on the Stroop Color and Word Test (r range, -0.23 to -0.24; P value range, .003-.005). After treatment, PVS indexes changed (P value range, <.001 to .01) and cognitive performance improved (P value range, <.001 to .03). Conclusion Differences in PVS indexes were observed among participants with differing severities of OSA and HCs. Indexes correlated with measures of cognitive function, and changes in indexes and improvement in cognitive performance were observed after treatment in participants with moderate OSA. © RSNA, 2024 Supplemental material is available for this article. See also the editorial by Port in this issue.


Asunto(s)
Disfunción Cognitiva , Imagen por Resonancia Magnética , Apnea Obstructiva del Sueño , Humanos , Apnea Obstructiva del Sueño/diagnóstico por imagen , Apnea Obstructiva del Sueño/complicaciones , Masculino , Femenino , Estudios Prospectivos , Adulto , Imagen por Resonancia Magnética/métodos , Disfunción Cognitiva/diagnóstico por imagen , Disfunción Cognitiva/etiología , Sistema Glinfático/diagnóstico por imagen , Imagen de Difusión Tensora/métodos , Persona de Mediana Edad
5.
J Magn Reson Imaging ; 59(2): 648-658, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-37249021

RESUMEN

BACKGROUND: The promoter variant rs17111237 in the CEP128 closely relates to radiotherapy (RT)-related brain necrosis in nasopharyngeal carcinoma (NPC) patients. PURPOSE: To explore RT-related dynamic alterations in brain morphology and their potential genetic mechanism, and to explore the modulatory effects of CEP128 genetic variants on RT-related brain morphological alterations in NPC patients. STUDY TYPE: Prospective, longitudinal. POPULATION: One hundred one patients with histopathologic ally-proven NPC (age 41.64 ± 9.63, 46 male), analyzed at baseline (pre-RT), 3-months post-RT and 6 months post-RT, and 19 sex-, age- and education-matched healthy controls. FIELD STRENGTH/SEQUENCE: 3D gradient echo brain volume (3D-BRAVO) and diffusion-weighted single-shot spin-echo echo-planar sequences at 3.0 T. ASSESSMENT: rs17111237 in CEP128 was detected by Sanger sequencing. Structural and diffusion images were processed with FreeSurfer and FSL. Morphometric similarity network (MSN) was constructed with nine cortical indices derived from structural and diffusion images. STATISTICAL TESTS: One-way ANOVA, chi-square test. Pearson's correlation analysis was conducted to measure the relationship between CEP128 gene-expression level in human brain and MSN alterations. Repeated analysis of variance performed to assess group differences in MSN and the modulatory effects of the CEP128 gene within patients. Significance level: P < 0.05, false-discovery rate correction. RESULTS: RT-related significant widespread MSN alterations were observed in the cortices of NPC patients. Notably, regional MSN alterations had a weak but significant negative correlation with the cortical pattern of CEP128 gene expression (r = -0.152). Furthermore, rs17111237 in the CEP128 had significant modulatory effects on the observed MSN alterations in NPC patients, with the modulatory effects being most obvious at 3 months post-RT. CONCLUSIONS: MSN has potential to serve as a sensitive biomarker to detect RT-related brain injury. Inter-brain regional and inter-patient variability of RT-related brain injuries may be attributed to the cortical expression of the CEP128 gene and the modulatory effects of the promoter variant rs17111237 in CEP128. EVIDENCE LEVEL: 2 TECHNICAL EFFICACY: Stage 2.


Asunto(s)
Lesiones Encefálicas , Neoplasias Nasofaríngeas , Humanos , Masculino , Encéfalo/diagnóstico por imagen , Encéfalo/patología , Lesiones Encefálicas/patología , Imagen por Resonancia Magnética/métodos , Carcinoma Nasofaríngeo , Neoplasias Nasofaríngeas/patología , Estudios Prospectivos
6.
FASEB J ; 37(10): e23176, 2023 10.
Artículo en Inglés | MEDLINE | ID: mdl-37665592

RESUMEN

Mycoplasma spp., the smallest self-replicating and genome-reduced organisms, have raised a great concern in both the medical and veterinary fields due to their pathogenicity. The molecular determinants of these wall-less bacterium efficiently use their limited genes to ensure successful infection of the host remain unclear. In the present study, we used the ruminant pathogen Mycoplasma bovis as a model to identify the key factors for colonization and invasion into host cells. We constructed a nonredundant fluorescent transposon mutant library of M. bovis using a modified transposon plasmid, and identified 34 novel adhesion-related genes based on a high-throughput screening approach. Among them, the ΔLppB mutant exhibited the most apparent decrease in adhesion to embryonic bovine lung (EBL) cells. The surface-localized lipoprotein LppB, which is highly conserved in Mycoplasma species, was then confirmed as a key factor for M. bovis adhesion with great immunogenicity. LppB interacted with various components (fibronectin, vitronectin, collagen IV, and laminin) of host extracellular matrix (ECM) and promoted plasminogen activation through tPA to degrade ECM. The 439-502 amino acid region of LppB is a critical domain, and F465 and Y493 are important residues for the plasminogen activation activity. We further revealed LppB as a key factor facilitating internalization through clathrin- and lipid raft-mediated endocytosis, which helps the Mycoplasma invade the host cells. Our study indicates that LppB plays a key role in Mycoplasma infection and is a potential new therapeutic and vaccine target for Mycoplasma species.


Asunto(s)
Mycoplasma bovis , Animales , Bovinos , Mycoplasma bovis/genética , Clatrina , Colágeno Tipo IV , Mutagénesis , Plasminógeno
7.
Int J Mol Sci ; 25(2)2024 Jan 09.
Artículo en Inglés | MEDLINE | ID: mdl-38255898

RESUMEN

Transcription factors are pivotal regulators in the cellular life process. Activating transcription factor 3 (ATF3), a member of the ATF/CREB (cAMP response element-binding protein) family, plays a crucial role as cells respond to various stresses and damage. As a transcription factor, ATF3 significantly influences signal transduction regulation, orchestrating a variety of signaling pathways, including apoptosis, ferroptosis, and cellular differentiation. In addition, ATF3 serves as an essential link between inflammation, oxidative stress, and immune responses. This review summarizes the recent advances in research on ATF3 activation and its role in regulating inflammatory responses, cell apoptosis, and ferroptosis while exploring the dual functions of ATF3 in these processes. Additionally, this article discusses the role of ATF3 in diseases related to pathogenic microbial infections. Our review may be helpful to better understand the role of ATF3 in cellular responses and disease progression, thus promoting advancements in clinical treatments for inflammation and oxidative stress-related diseases.


Asunto(s)
Factor de Transcripción Activador 3 , Apoptosis , Proteína de Unión a Elemento de Respuesta al AMP Cíclico , Ferroptosis , Humanos , Factor de Transcripción Activador 3/genética , Inflamación
8.
J Am Chem Soc ; 145(22): 12051-12058, 2023 Jun 07.
Artículo en Inglés | MEDLINE | ID: mdl-37218973

RESUMEN

The mechanism of the kinetic pH effect in hydrogen electrocatalysis, that is, the order-of-magnitude kinetic gap between the hydrogen oxidation and evolution reactions (HOR/HER) in acidic and alkaline electrolytes, has been drastically explored but still intractable to reach a consensus, which severely limits the catalyst advance for alkaline-based hydrogen energy technologies. Herein, the HOR/HER kinetics on a number of precious metal-based electrocatalysts are evaluated in electrolytes with pHs spanning a wide range from 1 to 13. Instead of a monotonous decrease with pH as generally believed, we surprisingly find a universal inflection-point behavior in the pH dependence of HOR/HER kinetics on these catalysts, with both the inflection-point pH and the acid-alkaline activity gap depending on the hydroxide binding energy of the catalyst. Based on a triple-path microkinetic model, in which hydronium (H3O+) and water (H2O) with and without formation of adsorbed hydroxide (OHad), respectively, act as hydrogen donors participating in HOR/HER in various pHs, we reveal that the formation of OHad should promote the HOR/HER kinetics mainly by improving the hydrogen-bond network in the electric double layer (EDL), rather than merely through modulating the energetics of surface reaction steps such as disassociation/formation of water. The present results and conclusions indicate that it is the interfacial EDL that dominates the substantial kinetic pH effects of hydrogen electrocatalysis.

9.
Lancet ; 400(10363): 1585-1596, 2022 11 05.
Artículo en Inglés | MEDLINE | ID: mdl-36341753

RESUMEN

BACKGROUND: The optimum systolic blood pressure after endovascular thrombectomy for acute ischaemic stroke is uncertain. We aimed to compare the safety and efficacy of blood pressure lowering treatment according to more intensive versus less intensive treatment targets in patients with elevated blood pressure after reperfusion with endovascular treatment. METHODS: We conducted an open-label, blinded-endpoint, randomised controlled trial at 44 tertiary-level hospitals in China. Eligible patients (aged ≥18 years) had persistently elevated systolic blood pressure (≥140 mm Hg for >10 min) following successful reperfusion with endovascular thrombectomy for acute ischaemic stroke from any intracranial large-vessel occlusion. Patients were randomly assigned (1:1, by a central, web-based program with a minimisation algorithm) to more intensive treatment (systolic blood pressure target <120 mm Hg) or less intensive treatment (target 140-180 mm Hg) to be achieved within 1 h and sustained for 72 h. The primary efficacy outcome was functional recovery, assessed according to the distribution in scores on the modified Rankin scale (range 0 [no symptoms] to 6 [death]) at 90 days. Analyses were done according to the modified intention-to-treat principle. Efficacy analyses were performed with proportional odds logistic regression with adjustment for treatment allocation as a fixed effect, site as a random effect, and baseline prognostic factors, and included all randomly assigned patients who provided consent and had available data for the primary outcome. The safety analysis included all randomly assigned patients. The treatment effects were expressed as odds ratios (ORs). This trial is registered at ClinicalTrials.gov, NCT04140110, and the Chinese Clinical Trial Registry, 1900027785; recruitment has stopped at all participating centres. FINDINGS: Between July 20, 2020, and March 7, 2022, 821 patients were randomly assigned. The trial was stopped after review of the outcome data on June 22, 2022, due to persistent efficacy and safety concerns. 407 participants were assigned to the more intensive treatment group and 409 to the less intensive treatment group, of whom 404 patients in the more intensive treatment group and 406 patients in the less intensive treatment group had primary outcome data available. The likelihood of poor functional outcome was greater in the more intensive treatment group than the less intensive treatment group (common OR 1·37 [95% CI 1·07-1·76]). Compared with the less intensive treatment group, the more intensive treatment group had more early neurological deterioration (common OR 1·53 [95% 1·18-1·97]) and major disability at 90 days (OR 2·07 [95% CI 1·47-2·93]) but there were no significant differences in symptomatic intracerebral haemorrhage. There were no significant differences in serious adverse events or mortality between groups. INTERPRETATION: Intensive control of systolic blood pressure to lower than 120 mm Hg should be avoided to prevent compromising the functional recovery of patients who have received endovascular thrombectomy for acute ischaemic stroke due to intracranial large-vessel occlusion. FUNDING: The Shanghai Hospital Development Center; National Health and Medical Research Council of Australia; Medical Research Futures Fund of Australia; China Stroke Prevention; Shanghai Changhai Hospital, Science and Technology Commission of Shanghai Municipality; Takeda China; Hasten Biopharmaceutic; Genesis Medtech; Penumbra.


Asunto(s)
Isquemia Encefálica , Accidente Cerebrovascular Isquémico , Accidente Cerebrovascular , Humanos , Adolescente , Adulto , Isquemia Encefálica/tratamiento farmacológico , Accidente Cerebrovascular/terapia , Presión Sanguínea/fisiología , Resultado del Tratamiento , China/epidemiología , Trombectomía/efectos adversos , Accidente Cerebrovascular Isquémico/tratamiento farmacológico , Accidente Cerebrovascular Isquémico/cirugía
10.
Exp Dermatol ; 32(6): 766-776, 2023 06.
Artículo en Inglés | MEDLINE | ID: mdl-36772997

RESUMEN

Serine protease inhibitor B7 (SERPINB7) mutations have been reported to cause Nagashima-type palmoplantar keratosis (NPPK), but their biological effects are largely unknown. We conducted whole-exome sequencing and identified a c.796C>T (p.Arg266Ter) mutation in SERPINB7 in a Chinese pedigree, which presented as an autosomal recessive inheritance pattern. We assessed the function of SERPINB7 in homozygous and heterozygous mutation carriers, and the results suggested that the single c.796C>T mutation may alter the subcellular localization of SERPINB7. One of the homozygous mutation patients (II-3) was treated with ixekizumab and showed moderate improvement in keratinization. In addition, we analysed the spatiotemporal expression of serpinb1l1 and serpinb1l3, the zebrafish homologue of human SERPINB7, which is expressed in larvae and adults. In larvae, both serpinb1l1 and serpinb1l3 were expressed in the digestive tract. Then, we performed RT-PCR on adult fins based on similarity to the site of NPPK expression in humans and found that the genes were expressed in five fins (pectoral, pelvic, dorsal, anal and caudal) of the zebrafish distal extremity. Taken together, our results demonstrated that the single c.796C>T (p.Arg266Ter) mutation may alter the location of SERPINB7-encoded protein in the skin, while zebrafish SERPINB7 homologue was expressed in adult fins. These findings will enable us to construct knock-out models to explore the pathogenesis of palmoplantar keratosis.


Asunto(s)
Queratodermia Palmoplantar , Serpinas , Adulto , Animales , Humanos , Inhibidores de Serina Proteinasa , Pez Cebra/genética , Mutación , Serpinas/genética , Linaje , Queratodermia Palmoplantar/genética , Queratodermia Palmoplantar/patología
11.
J Magn Reson Imaging ; 58(6): 1863-1874, 2023 12.
Artículo en Inglés | MEDLINE | ID: mdl-37022091

RESUMEN

BACKGROUND: Patients with hepatitis B virus-related cirrhosis (HBV-RC) exhibit progressive neurologic dysfunction from primary sensorimotor to high-order cognition, as their disease advances. However, the exact neurobiologic mechanisms and the potential association with gene-expression profiles are not fully understood. PURPOSE: To explore the hierarchical disorganization in the large-scale functional connectomes in HBV-RC patients and to investigate its potential underlying molecular basis. STUDY TYPE: Prospective. POPULATION: Fifty HBV-RC patients and 40 controls (Cohort 1) and 30 HBV-RC patients and 38 controls (Cohort 2). FIELD STRENGTH/SEQUENCE: Gradient-echo echo-planar and fast field echo sequences at 3.0 T (Cohort 1) and 1.5 T (Cohort 2). ASSESSMENT: Data were processed with Dpabi and the BrainSpace package. Gradient scores were evaluated from global to voxel level. Cognitive measurement and patients grouping were based on psychometric hepatic encephalopathy scores. The whole-brain microarray-based gene-expression data were obtained from the AIBS website. STATISTICAL TESTS: One-way ANOVA, chi-square test, two-sample t-test, Kruskal-Wallis test, Spearman's correlation coefficient (r), the gaussian random field correction, false discovery rate (FDR) correction and the Bonferroni correction. Significance level: P < 0.05. RESULTS: HBV-RC patients exhibited a robust and replicable connectome gradient dysfunction, which was significantly associated with the gene-expression profiles in both cohorts (r = 0.52 and r = 0.56, respectively). The most correlated genes were enriched in γ-aminobutyric acid (GABA) and GABA-related receptor genes (FDR q value <0.05). Moreover, the connectome gradient dysfunction at network level observed in HBV-RC patients correlated with their poor cognitive performance (Cohort 2: visual network, r = -0.56; subcortical network, r = 0.66; frontoparietal network, r = 0.51). DATA CONCLUSION: HBV-RC patients had hierarchical disorganization in the large-scale functional connectomes, which may underly their cognitive impairment. In addition, we showed the potential molecular mechanism of the connectome gradient dysfunction, which suggested the importance of GABA and GABA-related receptor genes. EVIDENCE LEVEL: 2 TECHNICAL EFFICACY: Stage 2.


Asunto(s)
Conectoma , Virus de la Hepatitis B , Humanos , Virus de la Hepatitis B/fisiología , Estudios Prospectivos , Imagen por Resonancia Magnética , Encéfalo/diagnóstico por imagen , Cirrosis Hepática/diagnóstico por imagen , Cirrosis Hepática/genética , Ácido gamma-Aminobutírico
12.
Vet Res ; 54(1): 107, 2023 Nov 17.
Artículo en Inglés | MEDLINE | ID: mdl-37978536

RESUMEN

Mycoplasma bovis is responsible for various inflammatory diseases in cattle. The prevention and control of M. bovis are complicated by the absence of effective vaccines and the emergence of multidrug-resistant strains, resulting in substantial economic losses worldwide in the cattle industry. Lipoproteins, vital components of the Mycoplasmas cell membrane, are deemed potent antigens for eliciting immune responses in the host upon infection. However, the functions of lipoproteins in M. bovis remain underexplored due to their low sequence similarity with those of other bacteria and the scarcity of genetic manipulation tools for M. bovis. In this study, the lipoprotein LppA was identified in all examined M. bovis strains. Utilizing immunoelectron microscopy and Western blotting, it was observed that LppA localizes to the surface membrane. Recombinant LppA demonstrated dose-dependent adherence to the membrane of embryonic bovine lung (EBL) cells, and this adhesion was inhibited by anti-LppA serum. In vitro binding assays confirmed LppA's ability to associate with fibronectin, collagen IV, laminin, vitronectin, plasminogen, and tPA, thereby facilitating the conversion of plasminogen to plasmin. Moreover, LppA was found to bind and enhance the accumulation of Annexin A2 (ANXA2) on the cell membrane. Disrupting LppA in M. bovis significantly diminished the bacterium's capacity to adhere to EBL cells, underscoring LppA's function as a bacterial adhesin. In conclusion, LppA emerges as a novel adhesion protein that interacts with multiple host extracellular matrix proteins and ANXA2, playing a crucial role in M. bovis's adherence to host cells and dissemination. These insights substantially deepen our comprehension of the molecular pathogenesis of M. bovis.


Asunto(s)
Anexina A2 , Enfermedades de los Bovinos , Infecciones por Mycoplasma , Mycoplasma bovis , Animales , Bovinos , Mycoplasma bovis/fisiología , Adhesión Bacteriana/fisiología , Plasminógeno/metabolismo , Anexina A2/metabolismo , Lipoproteínas/genética , Matriz Extracelular , Infecciones por Mycoplasma/veterinaria , Infecciones por Mycoplasma/microbiología , Enfermedades de los Bovinos/microbiología
13.
Chem Soc Rev ; 51(4): 1529-1546, 2022 Feb 21.
Artículo en Inglés | MEDLINE | ID: mdl-35138316

RESUMEN

It is essential to realize an expected low usage of platinum (Pt) in proton exchange membrane fuel cells (PEMFCs) for the large-scale market penetration of PEMFC-powered vehicles. As well as seeking Pt-based catalysts with a high specific activity, improving Pt utilization through structure optimization of the catalyst layer (CL) has been the main route and apparently a more practical way so far to develop high-performance low-Pt PEMFCs. Despite the significant progress achieved in the past 2-3 decades, a visible gap remains between the current Pt demand of automobile PEMFCs and the target value. To further increase Pt utilization, insights from previous studies are necessary. This review analyzes the structural factors that impact the current-generation efficiency of Pt in PEMFC electrodes in great detail, with emphasis particularly put on the mechanistic and molecule-level insights into the structural effects. The contents include the so-called local transport resistance associated with the permeation and diffusion of oxygen molecules in the ionomer film covering the Pt surface, regulation of ionomer aggregation through molecular interactions between ink components, modulation of ionomer distribution through pore size exclusion and surface electrostatic interaction of the carbon support, optimization of the coupling between the reaction and transport processes through graded composition, and the formation of highways of protons, electrons, and gas molecules through component alignment. We provide a critical analysis of the measurement methods and theoretical models assessing the local transport resistance, which is considered as a crucial issue in the current-generation efficiency of Pt in ultralow-Pt CL. Finally, new opportunities toward the further promotion of Pt utilization are proposed. These subjects and discussions should be of great significance in the rational design and precise fabrication of PEMFC electrodes, and may also inspire similar subjects in other electrochemical energy technologies such as water electrolysis, CO2 reduction, and batteries.


Asunto(s)
Platino (Metal) , Protones , Catálisis , Suministros de Energía Eléctrica , Electrodos , Humanos , Platino (Metal)/química
14.
Angew Chem Int Ed Engl ; 62(27): e202217976, 2023 Jul 03.
Artículo en Inglés | MEDLINE | ID: mdl-37129537

RESUMEN

High-entropy alloy (HEA) catalysts have been widely studied in electrocatalysis. However, identifying atomic structure of HEA with complex atomic arrangement is challenging, which seriously hinders the fundamental understanding of catalytic mechanism. Here, we report a HEA-PdNiRuIrRh catalyst with remarkable mass activity of 3.25 mA µg-1 for alkaline hydrogen oxidation reaction (HOR), which is 8-fold enhancement compared to that of commercial Pt/C. Through machine learning potential-based Monte Carlo simulation, we reveal that the dominant Pd-Pd-Ni/Pd-Pd-Pd bonding environments and Ni/Ru oxophilic sites on HEA surface are beneficial to the optimized adsorption/desorption of *H and enhanced *OH adsorption, contributing to the excellent HOR activity and stability. This work provides significant insights into atomic structure and catalytic mechanism for HEA and offers novel prospects for developing advanced HOR electrocatalysts.

15.
J Am Chem Soc ; 144(28): 12661-12672, 2022 Jul 20.
Artículo en Inglés | MEDLINE | ID: mdl-35732007

RESUMEN

Precisely tailoring the electronic structures of electrocatalysts to achieve an optimum hydroxide binding energy (OHBE) is vital to the alkaline hydrogen oxidation reaction (HOR). As a promising alternative to the Pt-group metals, considerable efforts have been devoted to exploring highly efficient Ni-based catalysts for alkaline HOR. However, their performances still lack practical competitiveness. Herein, based on insights from the molecular orbital theory and the Hammer-Nørskov d-band model, we propose an ingenious surface oxygen insertion strategy to precisely tailor the electronic structures of Ni electrocatalysts, simultaneously increasing the degree of energy-level alignment between the adsorbed hydroxide (*OH) states and surface Ni d-band and decreasing the degree of anti-bonding filling, which leads to an optimal OHBE. Through the pyrolysis procedure mediated by a metal-organic framework at a low temperature under a reducing atmosphere, the obtained oxygen-inserted two atomic-layer Ni shell-modified Ni metal core nanoparticle (Ni@Oi-Ni) exhibits a remarkable alkaline HOR performance with a record mass activity of 85.63 mA mg-1, which is 40-fold higher than that of the freshly synthesized Ni catalyst. Combining CO stripping experiments with ab initio calculations, we further reveal a linear relationship between the OHBE and the content of inserted oxygen, which thus results in a volcano-type correlation between the OH binding strength and alkaline HOR activity. This work indicates that the oxygen insertion into the top-surface layers is an efficient strategy to regulate the coordination environment and electronic structure of Ni catalysts and identifies the dominate role of OH binding strength in alkaline HOR.

16.
Epilepsia ; 63(1): 244-251, 2022 01.
Artículo en Inglés | MEDLINE | ID: mdl-34806164

RESUMEN

OBJECTIVE: This study was undertaken to investigate the COVID-19 vaccine uptake rate and possible postvaccination effects in adults with epilepsy. METHODS: We invited adults with epilepsy attending three centers in China from July 24 to August 31, 2021 to participate in this study. We also asked age- and sex-matched controls among people attending for other chronic neuropsychiatric conditions and healthy controls accompanying people with illness attending the hospitals to participate. We excluded people who, under the national guidelines, had evident contradictions to vaccination. Participants were interviewed face-to-face using questionnaires. Vaccine uptake and postvaccine adverse events among the people with epilepsy were compared with those with neuropsychiatric conditions and controls. We also compared the willingness and reasons for hesitancy among unvaccinated participants. RESULTS: We enrolled 981 people, of whom 491 had epilepsy, 217 had other neuropsychiatric conditions, and 273 were controls. Forty-two percent of those with epilepsy had had the first dose of a vaccine, compared with 93% of controls and 84% of the people with neuropsychiatric conditions (p < .0001). The majority (93.8%) of those immunized had inactivated vaccines. Among the unvaccinated people with epilepsy, 59.6% were willing to have the vaccine. Their main reasons for hesitation were potential adverse effects (53.3%) and concerns about losing seizure control (47.0%). The incidence of adverse events in the epilepsy group was similar to controls. Nineteen people with epilepsy reported an increase in seizure frequency. No episode of status epilepticus or prolonged seizures was reported. Two controls had their first-ever seizure, which was unlikely related to the vaccine. SIGNIFICANCE: The vaccine uptake rate in people with epilepsy was lower than in their same-age controls. The postvaccination effect was no higher than in controls. We found no evidence suggesting worsening seizures after vaccination. Measurement and education focused on increasing the vaccination rate in epilepsy are warranted.


Asunto(s)
Vacunas contra la COVID-19/administración & dosificación , COVID-19/prevención & control , Epilepsia , Convulsiones , Vacunación/estadística & datos numéricos , Adulto , Vacunas contra la COVID-19/efectos adversos , Estudios de Casos y Controles , China , Epilepsia/diagnóstico , Femenino , Humanos , Masculino , SARS-CoV-2 , Convulsiones/diagnóstico , Vacunas
17.
Eur Radiol ; 32(10): 7036-7047, 2022 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-35687134

RESUMEN

OBJECTIVES: To investigate the effects of standard radiotherapy on temporal white matter (WM) and its relationship with radiation necrosis (RN) in patients with nasopharyngeal carcinoma (NPC), and to determine the predictive value of WM volume alterations at the early stage for RN occurrence at the late-delay stage. METHODS: Seventy-four treatment-naive NPC patients treated with standard radiotherapy were longitudinally followed up for 36 months. Structural MRIs were collected at multiple time points during the first year post-radiotherapy. Longitudinal structural images were processed using FreeSurfer. Linear mixed models were used to delineate divergent trajectories of temporal WM changes between patients who developed RN and who did not. Four machine learning methods were used to construct predictive models for RN with temporal WM volume alterations at early-stage. RESULTS: The superior temporal gyrus (STG) had divergent atrophy trajectories in NPC patients with different outcomes (RN vs. NRN) post-radiotherapy. Patients with RN showed more rapid atrophy than those with NRN. A predictive model constructed with temporal WM volume alterations at early-stage post-radiotherapy had good performance for RN; the areas under the curve (AUC) were 0.879 and 0.806 at 1-3 months and 6 months post-radiotherapy, respectively. Moreover, the predictive model constructed with absolute temporal volume at 1-3 months post-radiotherapy also presented good performance; the AUC was 0.842, which was verified by another independent dataset (AUC = 0.773). CONCLUSIONS: NPC patients with RN had more sharp atrophy in the STG than those with NRN. Temporal WM volume at early-stage post-radiotherapy may serve as an in vivo biomarker to identify and predict RN occurrence. KEY POINTS: • The STG had divergent atrophy trajectories in NPC patients with different outcomes (RN vs. NRN) post-radiotherapy. • Although both groups exhibited time-dependent atrophy in the STG, the patients with RN showed a more rapid volume decrease than those with NRN. • Temporal WM volume alteration (or absolute volume) at the early stage could predict RN occurrence at the late-delay stage after radiotherapy.


Asunto(s)
Neoplasias Nasofaríngeas , Traumatismos por Radiación , Sustancia Blanca , Atrofia/patología , Biomarcadores , Humanos , Carcinoma Nasofaríngeo/patología , Carcinoma Nasofaríngeo/radioterapia , Neoplasias Nasofaríngeas/patología , Neoplasias Nasofaríngeas/radioterapia , Necrosis/patología , Traumatismos por Radiación/etiología , Sustancia Blanca/diagnóstico por imagen , Sustancia Blanca/patología
18.
BMC Infect Dis ; 22(1): 579, 2022 Jun 28.
Artículo en Inglés | MEDLINE | ID: mdl-35764948

RESUMEN

BACKGROUND: The G8 rotavirus genotype has been detected frequently in children in many countries and even became the predominant strain in sub-Saharan African countries, while there are currently no reports from China. In this study we described the genetic characteristics and evolutionary relationship between rotavirus strains from Guangzhou in China and the epidemic rotavirus strains derived from GenBank, 2020-2021. METHODS: Virus isolation and subsequent next-generation sequencing were performed for confirmed G8P[8] specimens. The genetic characteristics and evolutionary relationship were analyzed in comparison with epidemic rotavirus sequences obtained from GenBank. RESULTS: The two Guangzhou G8 strains were DS-1-like with the closest genetic distance to strains circulating in Southeast Asia. The VP7 genes of the two strains were derived from a human, not an animal G8 rotavirus. Large genetic distances in several genes suggested that the Guangzhou strains may not have been transmitted directly from Southeast Asian countries, but have emerged following reassortment events. CONCLUSIONS: We report the whole genome sequence information of G8P[8] rotaviruses recently detected in China; their clinical and epidemiological significance remains to be explored further.


Asunto(s)
Infecciones por Rotavirus , Rotavirus , Animales , Genoma Viral , Genotipo , Filogenia , Rotavirus/genética , Infecciones por Rotavirus/epidemiología
19.
J Chem Phys ; 156(10): 104701, 2022 Mar 14.
Artículo en Inglés | MEDLINE | ID: mdl-35291796

RESUMEN

The microstructural features and charge-potential relation of an electric double layer (EDL) at a stepped Pt(553)/water interface are investigated using ab initio molecular dynamics simulation. The results indicate that the chemisorbed O-down water molecules gather at the (110) step sites, while the (111) terrace sites are covered by the H-down water molecules, which greatly weakens the push-back effect of interface water on the spillover electrons of the stepped surface and, therefore, results in a much more positive potential of zero charge (PZC) than the extended low-index Pt surfaces. It is further revealed that around the PZC, the change in the surface charge density is dominated by the change in the coverage of chemisorbed water molecules, while EDL charging is the main cause of the change in the surface charge density at potential away from the PZC, thus leading to an S-shaped charge-potential relation and a maximum interface capacitance around PZC. Our results make up for the current lack of the atomic-scale understanding of the EDL microstructures and charge-potential relation on the real electrode surfaces with plentiful step and defect sites.

20.
Angew Chem Int Ed Engl ; 61(28): e202117178, 2022 Jul 11.
Artículo en Inglés | MEDLINE | ID: mdl-35037704

RESUMEN

Transition metal-based electrocatalysts will undergo surface reconstruction to form active oxyhydroxide-based hybrids, which are regarded as the "true-catalysts" for the oxygen evolution reaction (OER). Much effort has been devoted to understanding the surface reconstruction, but little on identifying the origin of the enhanced performance derived from the substrate effect. Herein, we report the electrochemical synthesis of amorphous CoOOH layers on the surface of various cobalt sulfides (CoSα ), and identify that the reduced intermolecular energy gap (Δinter ) between the valence band maximum (VBM) of CoOOH and the conduction band minimum (CBM) of CoSα can accelerate the formation of OER-active high-valent Co4+ species. The combination of electrochemical and in situ spectroscopic approaches, including cyclic voltammetry (CV), operando electron paramagnetic resonance (EPR) and Raman, reveals that Co species in the CoOOH/Co9 S8 are more readily oxidized to CoO2 /Co9 S8 than in CoOOH and other CoOOH/CoSα . This work provides a new design principle for transition metal-based OER electrocatalysts.

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