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1.
Science ; 385(6710): 744-752, 2024 Aug 16.
Artigo em Inglês | MEDLINE | ID: mdl-39146426

RESUMO

Air sensitivity remains a substantial barrier to the commercialization of sodium (Na)-layered oxides (NLOs). This problem has puzzled the community for decades because of the complexity of interactions between air components and their impact on both bulk and surfaces of NLOs. We show here that water vapor plays a pivotal role in initiating destructive acid and oxidative degradations of NLOs only when coupled with carbon dioxide or oxygen, respectively. Quantification analysis revealed that reducing the defined cation competition coefficient (η), which integrates the effects of ionic potential and sodium content, and increasing the particle size can enhance the resistance to acid attack, whereas using high-potential redox couples can eliminate oxidative degradation. These findings elucidate the underlying air deterioration mechanisms and rationalize the design of air-stable NLOs.

2.
Am J Transl Res ; 16(7): 3385-3394, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-39114686

RESUMO

BACKGROUND: Surgery is an important treatment modality for patients with digestive system tumors, and perioperative management is crucial for the patients' recovery and quality of life. During the perioperative period, significant changes can occur in the oral environment of patients, such as dry mouth, mucosal ulceration, and oral infections. These issues not only cause discomfort to the patients but may also affect postoperative recovery and treatment outcomes. Therefore, it is essential to investigate and analyze the oral environment during the perioperative period in patients with digestive system tumors. AIM: This study aims to investigate the oral health status in patients with digestive system tumors during the perioperative period and analyze the influencing factors. METHODS: In this retrospective study, a total of 242 patients with digestive system tumors admitted to The Seventh Affiliated Hospital, Xinjiang Medical University from September 2021 to June 2023 were selected as the study population (patient group). During the same period, 245 healthy volunteers who received oral examinations were selected as the healthy group. The study compared the oral hygiene environment of the two groups, including the Dental Plaque Index (DI), Calculus Index (CI), and Periodontal Disease Index (PDI). Measurements were taken at admission (T0), 1 hour before surgery (T1), and 3 days after surgery (T2). Based on the PDI index, the patient group was divided into a periodontal disease group (PDI ≥ 3, n = 196) and a periodontal healthy group (PDI < 3, n = 46). The risk factors for the development of periodontal disease in digestive system tumor patients were analyzed, considering variables such as gender, age, BMI, smoking status, alcohol consumption frequency, monthly income, tumor type, oral self-care habits, low-grade inflammation, and nutritional status. RESULTS: The DI, CI and PDI indexes in patient group were higher than those in healthy group (3.23±0.64 vs 1.46±0.43, 1.92±0.46 vs 1.21±0.41, 3.83±0.79 vs 2.65±0.69, all P < 0.05). DI index, CI index and PDI index at T1 and T2 were significantly lower than those at T0 (P < 0.05), and these indices at T2 were slightly higher than T1, but the difference was not statistically significant (all P > 0.05). Multivariate analyses identified high levels of high-sensitivity C-Reactive Protein [OR: 15.070 (1.611-140.951)], low levels of hemoglobin [OR: 0.239 (0.058-0.981)], and presence of dental caries [OR: 246.737 (1.160-52464.597)] as risk factors associated with periodontal disease in patients with digestive system tumors. CONCLUSION: It is important to enhance the attention and management of the oral environment during the perioperative period for patients with digestive system tumors.

3.
J Am Chem Soc ; 146(32): 22220-22235, 2024 Aug 14.
Artigo em Inglês | MEDLINE | ID: mdl-39088252

RESUMO

High-voltage layered oxide cathodes attract great attention for sodium-ion batteries (SIBs) due to the potential high energy density, but high voltage usually leads to rapid capacity decay. Herein, a stable high-voltage NaLi0.1Ni0.35Mn0.3Ti0.25O2 cathode with a ribbon-ordered superlattice is reported, and the intrinsic coupling mechanism between structure evolution and the anion redox reaction (ARR) is revealed. Li introduction constructs a special Li-O-Na configuration activating reversible nonbonded O 2p (|O2p)-type ARR and regulates the structure evolution way, enabling the reversible Li ions out-of-layer migration instead of the irreversible transition metal ions out-of-layer migration. The reversible structure evolution enhances the reversibility of the bonded O 2p (O2p)-type ARR and inhibits the generation of oxygen dimers, thus suppressing the irreversible molecular oxygen (O2)-type ARR. After the structure regulation, the structure evolution becomes reversible, |O2p-type ARR is activated, O2p-type ARR becomes stable, and O2-type ARR is inhibited, which largely suppresses the capacity degradation and voltage decay. The discharge capacity is increased from 154 to 168 mA h g-1, the capacity retention after 200 cycles significantly increases from 35 to 84%, and the voltage retention increases from 78 to 93%. This study presents some guidance for the design of high-voltage, O3-type oxide cathodes for high-performance SIBs.

4.
J Am Chem Soc ; 146(34): 24167-24176, 2024 Aug 28.
Artigo em Inglês | MEDLINE | ID: mdl-39162130

RESUMO

Redox-active transition metal oxides (TMOs) play crucial roles in diverse energy storage and conversion technologies, such as batteries and pseudocapacitors. These materials show intricate electrochemical charge storage processes, encompassing both bulk ion-intercalation, typical of battery electrodes, and pseudocapacitive-like behavior localized near the surfaces. However, understanding the underlying mechanisms of charge storage in redox-active TMOs is challenging due to the coexistence of these behaviors. In this study, we propose an integrated approach that combines operando electrochemical and optical techniques to disentangle the contributions of bulk and surface phenomena. Using birnessite δ-MnO2-x as a model system, we account for surface pseudocapacitive-like layers and employ a refined model that incorporates both surface reactions and bulk chemical diffusion. This methodology allows us to extract essential kinetic parameters, establishing a fundamental framework for unraveling surface and bulk electrochemical processes. This advancement provides a valuable tool for the rational design of energy storage devices, enhancing our ability to tailor these materials for specific applications.

5.
Gene ; 931: 148891, 2024 Aug 24.
Artigo em Inglês | MEDLINE | ID: mdl-39187139

RESUMO

The Chubao black-head goat is a novel hybrid breed that combines the advantages of Macheng black goats, such as good reproductive performance, strong adaptability, and resistance to rough feeding, with the superior growth and meat characteristics of Boer goats. Given the substantial economic importance of growth (such as birth weight, body height, body length, and chest circumference across different growth stages) and reproductive traits (particularly average litter size after first parity), the aim of this study was to identify significant SNPs and candidate genes associated with these traits in Chubao black-head goats. Through whole-genome sequencing (with 34 goats at approximately 15× coverage and 466 goats at approximately 1× coverage), genotype imputation, and quality control, 22,665,331 SNPs were identified and subsequently used for genetic analyses. Heritability estimates indicated that growth traits exhibit moderate to high heritability (ranging from 0.297 ± 0.071 to 0.535 ± 0.118), while reproductive traits demonstrated low to moderate heritability (with a value of 0.220 ± 0.108). By performing FarmCPU-based genome-wide association studies, we identified 48 potentially significant SNPs associated with growth traits and 7 with reproductive traits. Additionally, 85 candidate genes (such as COL14A1, ZNF148, and TTC39C) linked to growth traits were identified and enriched in pathways associated with fundamental molecular biological activities such as protein deubiquitination, regulation of mRNA stability, and the MAPK signaling pathway. Furthermore, 10 candidate genes (such as SOHLH2, CCNA2, and SOX7) associated with reproductive traits were identified and enriched in pathways related to specific reproductive processes such as oocyte differentiation, endoderm formation, and progesterone-mediated oocyte maturation. Overall, these findings provide valuable preliminary insights into the molecular mechanisms underlying growth and reproductive traits in Chubao black-head goats. However, further functional validation is needed to effectively use these potential SNPs and candidate genes in improving the breeding of these traits in this breed.

6.
Front Cell Dev Biol ; 12: 1397954, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38915448

RESUMO

This comprehensive review inspects the therapeutic potential of mesenchymal stem cell-derived extracellular vesicles (MSC-EVs) across multiple organ systems. Examining their impact on the integumentary, respiratory, cardiovascular, urinary, and skeletal systems, the study highlights the versatility of MSC-EVs in addressing diverse medical conditions. Key pathways, such as Nrf2/HO-1, consistently emerge as central mediators of their antioxidative and anti-inflammatory effects. From expediting diabetic wound healing to mitigating oxidative stress-induced skin injuries, alleviating acute lung injuries, and even offering solutions for conditions like myocardial infarction and renal ischemia-reperfusion injury, MSC-EVs demonstrate promising therapeutic efficacy. Their adaptability to different administration routes and identifying specific factors opens avenues for innovative regenerative strategies. This review positions MSC-EVs as promising candidates for future clinical applications, providing a comprehensive overview of their potential impact on regenerative medicine.

7.
J Integr Med ; 22(4): 493-502, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38853116

RESUMO

OBJECTIVE: Hepatolenticular degeneration (HLD) is an autosomal recessive disorder that manifests as multiorgan damage due to impaired copper (Cu) metabolism. Female patients with HLD often experience reproductive impairments. This study investigated the protective effect of berberine against ovarian damage in toxic-milk (TX) mice, a murine model for HLD. METHODS: Mice were categorized into control group, HLD TX group (HLD group), penicillamine (Cu chelator)-treated TX group and berberine-treated TX group. Body weight, ovary weight and the number of ovulated eggs were recorded. Follicular morphology and cellular ultrastructure were examined. Total iron, ferrous iron (Fe2+) and trivalent iron (Fe3+) levels, as well as malondialdehyde (MDA), glutathione (GSH) and oxidized glutathione (GSSG), were measured in the ovaries. Western blot analysis was used to analyze the expression of proteins related to ferroptosis and endoplasmic reticulum (ER) stress. RESULTS: Ovarian tissue damage was evident in the HLD group, with a significant increase in ferroptosis and ER stress compared to the control group. This damage was inhibited by treatment with penicillamine, a Cu chelator. Compared with the HLD group, berberine increased the number of ovulations, and improved ovarian morphology and ultrastructure. Further, we found that berberine reduced total iron, Fe2+, MDA and GSSG levels, elevated GSH levels, decreased the expression of the ferroptosis marker protein prostaglandin-endoperoxide synthase 2 (PTGS2), and increased glutathione peroxidase 4 (GPX4) expression. Furthermore, berberine inhibited the expression of ER stress-associated proteins mediated by the protein kinase RNA-like ER kinase (PERK) pathway. CONCLUSION: Ferroptosis and ER stress are involved in Cu-induced ovarian damage in TX mice. Berberine ameliorates ovarian damage in HLD TX mice by inhibiting ferroptosis and ER stress. Please cite this article as: Liu QZ, Han H, Fang XR, Wang LY, Zhao D, Yin MZ, Zhang N, Jiang PY, Ji ZH, Wu LM. Berberine alleviates ovarian tissue damage in mice with hepatolenticular degeneration by suppressing ferroptosis and endoplasmic reticulum stress. J Integr Med. 2024; 22(4): 494-503.


Assuntos
Berberina , Estresse do Retículo Endoplasmático , Ferroptose , Degeneração Hepatolenticular , Ovário , Animais , Feminino , Ferroptose/efeitos dos fármacos , Estresse do Retículo Endoplasmático/efeitos dos fármacos , Camundongos , Berberina/farmacologia , Ovário/efeitos dos fármacos , Ovário/metabolismo , Degeneração Hepatolenticular/tratamento farmacológico , Degeneração Hepatolenticular/metabolismo , Degeneração Hepatolenticular/genética , Modelos Animais de Doenças , Cobre , Glutationa/metabolismo , Ferro/metabolismo , Malondialdeído/metabolismo
8.
Small ; : e2401497, 2024 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-38693067

RESUMO

Manganese-based lithium-rich layered oxides (Mn-LLOs) are promising candidate cathode materials for lithium-ion batteries, however, the severe voltage decay during cycling is the most concern for their practical applications. Herein, an Mn-based composite nanostructure constructed Li2MnO3 (LMO@Li2MnO3) is developed via an ultrathin amorphous functional oxide LixMnOy coating at the grain surface. Due to the thin and universal LMO amorphous surface layer etched from the lithiation process by the high-concentration alkaline solution, the structural and interfacial stability of Li2MnO3 are enhanced apparently, showing the significantly improved voltage maintenance, cycle stability, and energy density. In particular, the LMO@Li2MnO3 cathode exhibits zero voltage decay over 200 cycles. Combining with ex situ spectroscopic and microscopic techniques, the Mn2+/4+ coexisted behavior of the amorphous LMO is revealed, which enables the stable electrochemistry of Li2MnO3. This work provides new possible routes for suppressing the voltage decay of Mn-LLOs by modifying with the composite functional unit construction.

9.
ACS Nano ; 18(20): 13397-13405, 2024 May 21.
Artigo em Inglês | MEDLINE | ID: mdl-38728672

RESUMO

Integrating anion-redox capacity with orthodox cation-redox capacity is deemed as a promising solution for high-energy-density battery cathodes surmounting the present technical bottlenecks. However, the evolution of oxidized oxygen species during the electrochemical or chemical process easily jeopardizes the reversibility of oxygen redox and remains poorly understood. Herein, we showcase the gradual conversion of the π-interacting oxygen (localized hole states on O) to the σ-interacting oxygen upon resting at a high voltage for P3-type Na0.6Li0.2Mn0.8O2 with nominally stable ribbon-like superstructure, accompanied by the O-O dimerization and the local structural reorganization. We further pinpoint an abnormal Li+ migration process from the alkali-metal layer to the transition-metal layer for desodiated P3-Na0.6Li0.2Mn0.8O2, thereby leading to a partial reconstruction of the ribbon superstructure. The high-voltage plateau of oxygen-redox cathodes is concluded to be exclusively controlled by the oxygen stabilization mechanism rather than the superstructure ordering. In addition, there exists a kinetic competition between π and σ interaction during the uninterrupted electrochemical process.

10.
Adv Mater ; 36(32): e2405519, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38801117

RESUMO

Pushing intercalation-type cathode materials to their theoretical capacity often suffers from fragile Li-deficient frameworks and severe lattice strain, leading to mechanical failure issues within the crystal structure and fast capacity fading. This is particularly pronounced in layered oxide cathodes because the intrinsic nature of their structures is susceptible to structural degradation with excessive Li extraction, which remains unsolved yet despite attempts involving elemental doping and surface coating strategies. Herein, a mechanochemical strengthening strategy is developed through a gradient disordering structure to address these challenges and push the LiCoO2 (LCO) layered cathode approaching the capacity limit (256 mAh g-1, up to 93% of Li utilization). This innovative approach also demonstrates exceptional cyclability and rate capability, as validated in practical Ah-level pouch full cells, surpassing the current performance benchmarks. Comprehensive characterizations with multiscale X-ray, electron diffraction, and imaging techniques unveil that the gradient disordering structure notably diminishes the anisotropic lattice strain and exhibits high fatigue resistance, even under extreme delithiation states and harsh operating voltages. Consequently, this designed LCO cathode impedes the growth and propagation of particle cracks, and mitigates irreversible phase transitions. This work sheds light on promising directions toward next-generation high-energy-density battery materials through structural chemistry design.

11.
Small ; : e2401839, 2024 May 28.
Artigo em Inglês | MEDLINE | ID: mdl-38804822

RESUMO

Co-free Li-rich Mn-based cathode materials are garnering great interest because of high capacity and low cost. However, their practical application is seriously hampered by the irreversible oxygen escape and the poor cycling stability. Herein, a reversible lattice adjustment strategy is proposed by integrating O vacancies and B doping. B incorporation increases TM─O (TM: transition metal) bonding orbitals whereas decreases the antibonding orbitals. Moreover, B doping and O vacancies synergistically increase the crystal orbital bond index values enhancing the overall covalent bonding strength, which makes TM─O octahedron more resistant to damage and enables the lattice to better accommodate the deformation and reaction without irreversible fracture. Furthermore, Mott-Hubbard splitting energy is decreased due to O vacancies, facilitating electron leaps, and enhancing the lattice reactivity and capacity. Such a reversible lattice, more amenable to deformation and forestalling fracturing, markedly improves the reversibility of lattice reactions and mitigates TM migration and the irreversible oxygen redox which enables the high cycling stability and high rate capability. The modified cathode demonstrates a specific capacity of 200 mAh g-1 at 1C, amazingly sustaining the capacity for 200 cycles without capacity degradation. This finding presents a promising avenue for solving the long-term cycling issue of Li-rich cathode.

12.
Neural Netw ; 176: 106348, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38735099

RESUMO

Binary matrix factorization is an important tool for dimension reduction for high-dimensional datasets with binary attributes and has been successfully applied in numerous areas. This paper presents a collaborative neurodynamic optimization approach to binary matrix factorization based on the original combinatorial optimization problem formulation and quadratic unconstrained binary optimization problem reformulations. The proposed approach employs multiple discrete Hopfield networks operating concurrently in search of local optima. In addition, a particle swarm optimization rule is used to reinitialize neuronal states iteratively to escape from local minima toward better ones. Experimental results on eight benchmark datasets are elaborated to demonstrate the superior performance of the proposed approach against six baseline algorithms in terms of factorization error. Additionally, the viability of the proposed approach is demonstrated for pattern discovery on three datasets.


Assuntos
Algoritmos , Redes Neurais de Computação , Humanos , Reconhecimento Automatizado de Padrão/métodos , Neurônios/fisiologia
13.
Chem Biol Interact ; 396: 111060, 2024 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-38761876

RESUMO

Copper is a toxic heavy metal that causes various damage when it accumulates in the body beyond the physiological threshold. Wilson disease (WD) is an inherited disorder characterized by impaired copper metabolism. Reproductive damage in male patients with WD is gradually attracting attention. However, the underlying mechanisms of copper toxicity are unclear. In this study, we investigated the role of inflammation and PANoptosis in testicular damage and impaired spermatogenesis caused by copper deposition using the WD model toxic milk (TX) mice. Copper chelator-penicillamine and toll-like receptor 4 (TLR4) inhibitor-eritoran were used to intervene in TX mice in our animal experiment methods. Testis samples were collected from mice for further analysis. The results showed that the morphology and ultrastructure of the testis and epididymis in TX mice were damaged, and the sperm counts decreased significantly. The TLR4/nuclear factor kappa-B (NF-κB) signaling pathway was activated by copper deposition, which led to the upregulation of serum and testicular inflammatory factors in TX mice. Meanwhile, pyroptosis, apoptosis, and necroptosis were significant in the testis of TX mice. Both chelated copper or inhibited TLR4 expression markedly suppressed the TLR4/NF-κB signaling pathway, thereby reducing the expression of inflammatory factors. PANoptosis in the testis of TX mice was also reversed. Our study indicated that pathological copper exposure induces inflammation and PANoptosis through the TLR4/NF-κB signaling pathway, leading to toxic testicular damage and impaired spermatogenesis in WD.


Assuntos
Cobre , Degeneração Hepatolenticular , Inflamação , NF-kappa B , Transdução de Sinais , Espermatogênese , Testículo , Receptor 4 Toll-Like , Animais , Masculino , Receptor 4 Toll-Like/metabolismo , Cobre/toxicidade , Espermatogênese/efeitos dos fármacos , Testículo/efeitos dos fármacos , Testículo/metabolismo , Testículo/patologia , NF-kappa B/metabolismo , Transdução de Sinais/efeitos dos fármacos , Camundongos , Degeneração Hepatolenticular/patologia , Degeneração Hepatolenticular/metabolismo , Inflamação/induzido quimicamente , Inflamação/metabolismo , Inflamação/patologia , Apoptose/efeitos dos fármacos , Penicilamina/farmacologia
14.
Angew Chem Int Ed Engl ; 63(27): e202401373, 2024 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-38659181

RESUMO

Inorganic solid-state electrolytes (SSEs) play a vital role in high-energy all-solid-state batteries (ASSBs). However, the current method of SSE preparation usually involves high-energy mechanical ball milling and/or a high-temperature annealing process, which is not suitable for practical application. Here, a facile strategy is developed to realize the scalable synthesis of cost-effective aluminum-based oxyhalide SSEs, which involves a self-propagating method by the exothermic reaction of the raw materials. This strategy enables the synthesis of various aluminum-based oxyhalide SSEs with tunable components and high ionic conductivities (over 10-3 S cm-1 at 25 °C) for different cations (Li+, Na+, Ag+). It is elucidated that the amorphous matrix, which mainly consists of various oxidized chloroaluminate species that provide numerous sites for smooth ion migration, is actually the key factor for the achieved high conductivities. Benefit from their easy synthesis, low cost, and low weight, the aluminum-based oxyhalide SSEs synthesized by our approach could further promote practical application of high-energy-density ASSBs.

15.
Nat Commun ; 15(1): 3048, 2024 Apr 08.
Artigo em Inglês | MEDLINE | ID: mdl-38589497

RESUMO

Flexible pressure sensors can convert mechanical stimuli to electrical signals to interact with the surroundings, mimicking the functionality of the human skins. Piezocapacitive pressure sensors, a class of most widely used devices for artificial skins, however, often suffer from slow response-relaxation speed (tens of milliseconds) and thus fail to detect dynamic stimuli or high-frequency vibrations. Here, we show that the contact-separation behavior of the electrode-dielectric interface is an energy dissipation process that substantially determines the response-relaxation time of the sensors. We thus reduce the response and relaxation time to ~0.04 ms using a bonded microstructured interface that effectively diminishes interfacial friction and energy dissipation. The high response-relaxation speed allows the sensor to detect vibrations over 10 kHz, which enables not only dynamic force detection, but also acoustic applications. This sensor also shows negligible hysteresis to precisely track dynamic stimuli. Our work opens a path that can substantially promote the response-relaxation speed of piezocapacitive pressure sensors into submillisecond range and extend their applications in acoustic range.

16.
J Nanobiotechnology ; 22(1): 121, 2024 Mar 19.
Artigo em Inglês | MEDLINE | ID: mdl-38504264

RESUMO

BACKGROUND: Traditional pesticides are poorly water-soluble and suffer from low bioavailability. N-succinyl chitosan (NSCS) is a water-soluble chitosan derivative, has been recently used to encapsulate hydrophobic drugs to improve their bioavailability. However, it remains challenging to synthesize pesticides of a wide variety of water-soluble drugs and to scale up the production in a continuous manner. RESULTS: A synthetic method for preparing water-soluble nanopesticides with a polymer carrier was applied. The bioactive molecule BTL-11 was loaded into hollow NSCS to promote drug delivery, improve solubility and anti-fungal activity. The synthesized nanopesticides had well controlled sizes of 606 nm and the encapsulation rate was 80%. The release kinetics, drug toxicity and drug activity were further evaluated. The inhibitory activity of nanopesticides against Rhizoctonia solani (R. solani) was tested in vivo and in vitro. In vivo against R. solani trials revealed that BTL-11 has excellent control efficiency for cultivated rice leaf and sheath was 79.6 and 76.5%, respectively. By contrast, for BTL-11@NSCS NPs, the anti-fungal ability was strongly released and afforded significant control efficiencies of 85.9 and 81.1%. Those effects were significantly better than that of the agricultural fungicide azoxystrobin (51.5 and 66.5%). The proposed mechanism was validated by successfully predicting the synthesis outcomes. CONCLUSIONS: This study demonstrates that NSCS is a promising biocompatible carrier, which can enhance the efficacy of pesticides, synergistically improve plant disease resistance, protect crop growth, and can be used for the delivery of more insoluble pesticides.


Assuntos
Quitosana , Fungicidas Industriais , Micoses , Humanos , Quitosana/química , Preparações de Ação Retardada/farmacologia , Fungicidas Industriais/farmacologia , Interações Hidrofóbicas e Hidrofílicas , Água/química
17.
Angew Chem Int Ed Engl ; 63(20): e202402657, 2024 May 13.
Artigo em Inglês | MEDLINE | ID: mdl-38477874

RESUMO

The main group metals are commonly perceived as catalytically inert in the context of oxygen reduction reactions (ORR) due to the delocalized valence orbitals. Regulating the local environment and structure of metal center coordinated by nitrogen ligands (M-Nx) is a promising approach to accelerate catalytic dynamics. Herein, we, for the first time, report the atomically dispersed Al catalysts coordinated with N and C atoms for 4-electron ORR. The axial coordinated pyrrolyl N group (No) is constructed in the Al-N4-No moiety to regulate the p-band structure of Al center, effectively steering the local environment and structure of the square planar Al-N4 sites, which typically exhibit too strong interaction with ORR intermediates. The dynamic covalency competition of axial Al-No and Al-O bonding could endow the Al center with moderate hybridization between Al 3p orbital and O 2p orbital, alleviating the binding energy of ORR intermediates. The as-prepared Al-N4-No electrocatalyst exhibits excellent ORR activity, selectivity, and durability, along with the rapid kinetics as demonstrated by in situ Raman spectroscopy. This work offers a fundamental comprehension of the fine regulation on p-band and guides the rational design of main-group metal-based single atom catalysts.

18.
Nat Commun ; 15(1): 2777, 2024 Mar 30.
Artigo em Inglês | MEDLINE | ID: mdl-38555416

RESUMO

Garnet-type Li6.5La3Zr1.5Ta0.5O12 (LLZO) is considered a promising solid electrolyte, but the surface degradation in air hinders its application for all-solid-state battery. Recent studies have mainly focused on the final products of the LLZO surface reactions due to lacking of powerful in situ characterization methods. Here, we use ambient pressure X-ray spectroscopies to in situ investigate the dynamical evolution of LLZO surface in different gas environments. The newly developed ambient pressure mapping of resonant Auger spectroscopy clearly distinguishes the lithium containing species, including LiOH, Li2O, Li2CO3 and lattice oxygen. The reaction of CO2 with LLZO to form Li2CO3 is found to be a thermodynamically favored self-limiting reaction. On the contrary, the reaction of H2O with LLZO lags behind that of CO2, but intensifies at high pressure. More interestingly, the results provide direct spectroscopic evidence for the existence of Li+/H+ exchange and reveal the importance of the initial layer formed on clean electrolyte surface in determining their air stability. This work demonstrates that the newly developed in situ technologies pave a new way to investigate the oxygen evolution and surface degradation mechanism in energy materials.

19.
Adv Mater ; 36(24): e2312879, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38444241

RESUMO

Monodispersed microspheres play a major role in optical science and engineering, providing ideal building blocks for structural color materials. However, the method toward high solid content (HSC) monodispersed microspheres has remained a key hurdle. Herein, a facile access to harvest monodispersed microspheres based on the emulsion polymerization mechanism is demonstrated, where anionic and nonionic surfactants are employed to achieve the electrostatic and steric dual-stabilization balance in a synergistic manner. Monodispersed poly(styrene-butyl acrylate-methacrylic acid) colloidal latex with 55 wt% HSC is achieved, which shows an enhanced self-assembly efficiency of 280% compared with the low solid content (10 wt%) latex. In addition, Ag-coated colloidal photonic crystal (Ag@CPC) coating with near-zero refractive index is achieved, presenting the characteristics of metamaterials. And an 11-fold photoluminescence emission enhancement of CdSe@ZnS quantum dots is realized by the Ag@CPC metamaterial coating. Taking advantage of high assembly efficiency, easily large-scale film-forming of the 55 wt% HSC microspheres latex, robust Ag@CPC metamaterial coatings could be easily produced for passive cooling. The coating demonstrates excellent thermal insulation performance with theoretical cooling power of 30.4 W m-2, providing practical significance for scalable CPC architecture coatings in passive cooling.

20.
Nat Commun ; 15(1): 793, 2024 Jan 26.
Artigo em Inglês | MEDLINE | ID: mdl-38278808

RESUMO

Sexual development in Toxoplasma gondii is a multistep process that culminates in the production of oocysts, constituting approximately 50% of human infections. However, the molecular mechanisms governing sexual commitment in this parasite remain poorly understood. Here, we demonstrate that the transcription factors AP2XI-2 and AP2XII-1 act as negative regulators, suppressing merozoite-primed pre-sexual commitment during asexual development. Depletion of AP2XI-2 in type II Pru strain induces merogony and production of mature merozoites in an alkaline medium but not in a neutral medium. In contrast, AP2XII-1-depleted Pru strain undergoes several rounds of merogony and produces merozoites in a neutral medium, with more pronounced effects observed under alkaline conditions. Additionally, we identified two additional AP2XI-2-interacting proteins involved in repressing merozoite programming. These findings underscore the intricate regulation of pre-sexual commitment by a network of factors and suggest that AP2XI-2 or AP2XII-1-depleted Pru parasites can serve as a model for studying merogony in vitro.


Assuntos
Toxoplasma , Animais , Humanos , Toxoplasma/metabolismo , Merozoítos/metabolismo , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Proteínas de Protozoários/genética , Proteínas de Protozoários/metabolismo
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