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2.
Shock ; 61(3): 454-464, 2024 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-38412105

RESUMO

ABSTRACT: Immunosuppression, commonly accompanied by persistent inflammation, is a key feature in the later phase of sepsis. However, the pathophysiological mechanisms underlying this phenomenon remain unclear. Dendritic cells (DCs), specifically tolerogenic DCs (tolDCs), play a crucial role in this process by regulating immune responses through inducing T cell anergy and releasing anti-inflammatory cytokines. Nevertheless, the existing cell models are inadequate for investigating tolDCs during the immunosuppressive phase of sepsis. Therefore, this study aimed to develop a novel in vitro model to generate tolDCs under chronic inflammatory conditions. We have successfully generated tolDCs by exposing them to sublethal lipopolysaccharide (LPS) for 72 h while preserving cell viability. Considering that IL-10-induced tolDCs (IL-10-tolDCs) are well-established models, we compared the immunological tolerance between LPS-tolDCs and IL-10-tolDCs. Our findings indicated that both LPS-tolDCs and IL-10-tolDCs exhibited reduced expression of maturation markers, whereas their levels of inhibitory markers were elevated. Furthermore, the immunoregulatory activities of LPS-tolDCs and IL-10-tolDCs were found to be comparable. These dysfunctions include impaired antigen presenting capacity and suppression of T cell activation, proliferation, and differentiation. Notably, compared with IL-10-tolDCs, LPS-tolDCs showed a reduced response in maturation and cytokine production upon stimulation, indicating their potential as a better model for research. Overall, in comparison with IL-10-tolDCs, our data suggest that the immunological dysfunctions shown in LPS-tolDCs could more effectively elucidate the increased susceptibility to secondary infections during sepsis. Consequently, LPS-tolDCs have emerged as promising therapeutic targets for ameliorating the immunosuppressed state in septic patients.


Assuntos
Interleucina-10 , Sepse , Humanos , Interleucina-10/metabolismo , Células Dendríticas/metabolismo , Lipopolissacarídeos/farmacologia , Tolerância Imunológica , Sepse/metabolismo , Inflamação/metabolismo
4.
J Med Chem ; 67(5): 3400-3418, 2024 Mar 14.
Artigo em Inglês | MEDLINE | ID: mdl-38387069

RESUMO

The use of ß-lactam (BL) and ß-lactamase inhibitor combination to overcome BL antibiotic resistance has been validated through clinically approved drug products. However, unmet medical needs still exist for the treatment of infections caused by Gram-negative (GN) bacteria expressing metallo-ß-lactamases. Previously, we reported our effort to discover pan inhibitors of three main families in this class: IMP, VIM, and NDM. Herein, we describe our work to improve the GN coverage spectrum in combination with imipenem and relebactam. This was achieved through structure- and property-based optimization to tackle the GN cell penetration and efflux challenges. A significant discovery was made that inhibition of both VIM alleles, VIM-1 and VIM-2, is essential for broad GN coverage, especially against VIM-producing P. aeruginosa. In addition, pharmacokinetics and nonclinical safety profiles were investigated for select compounds. Key findings from this drug discovery campaign laid the foundation for further lead optimization toward identification of preclinical candidates.


Assuntos
Antibacterianos , Inibidores de beta-Lactamases , Humanos , Inibidores de beta-Lactamases/farmacologia , Inibidores de beta-Lactamases/uso terapêutico , Inibidores de beta-Lactamases/química , Antibacterianos/química , Imipenem/farmacologia , beta-Lactamases , Bactérias Gram-Negativas , Testes de Sensibilidade Microbiana
5.
Top Curr Chem (Cham) ; 381(6): 34, 2023 Nov 08.
Artigo em Inglês | MEDLINE | ID: mdl-37938363

RESUMO

Metal nanoparticles (NPs) are widely used in biomedicine, catalysis, environment, electronics, and other fields, which is closely related to its structural form. For this purpose, researchers have been looking for a simple, green, and controllable way to mass produce metal nanomaterials with desired characteristics (shape, size, stability, etc.). Due to the surface plasmon resonance (SPR) effect of metal nanoparticles, photoreduction method can control the morphology of metal nanoparticles well, which is also simple, large-scalable, and energy-saving. This review provides an overview of the photoreduction method for the synthesis of metal nanoparticles and discusses the factors such as the light source, pH value, reagents, and temperature on the morphology of the nanoparticles. Finally, the challenges and development trends in the controlled preparation of nanomaterials are proposed.


Assuntos
Nanopartículas Metálicas , Nanoestruturas , Catálise , Eletrônica , Metais
6.
Dis Model Mech ; 16(10)2023 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-37728477

RESUMO

Tissue injury-induced neutrophil recruitment is a prerequisite for the initiation and amplification of inflammatory responses. Although multiple proteases and enzymes involved in post-translational modification (PTM) of proteins regulate leukocyte recruitment, an unbiased functional screen of enzymes regulating inflammatory leukocyte recruitment has yet to be undertaken. Here, using a zebrafish tail fin amputation (TFA) model to screen a chemical library consisting of 295 compounds that target proteases and PTM enzymes, we identified multiple histone deacetylase (HDAC) inhibitors that modulate inflammatory neutrophil recruitment. AR-42, a pan-HDAC inhibitor, was shown to inhibit neutrophil recruitment in three different zebrafish sterile tissue injury models: a TFA model, a copper-induced neuromast damage and mechanical otic vesicle injury (MOVI) model, and a sterile murine peritonitis model. RNA sequencing analysis of AR-42-treated fish embryos revealed downregulation of neutrophil-associated cytokines/chemokines, and exogenous supplementation with recombinant human IL-1ß and CXCL8 partially restored the defective neutrophil recruitment in AR-42-treated MOVI model fish embryos. We thus demonstrate that AR-42 non-cell-autonomously modulates neutrophil recruitment by suppressing transcriptional expression of cytokines/chemokines, thereby identifying AR-42 as a promising anti-inflammatory drug for treating sterile tissue injury-associated diseases.


Assuntos
Inibidores de Histona Desacetilases , Peixe-Zebra , Humanos , Animais , Camundongos , Inibidores de Histona Desacetilases/farmacologia , Infiltração de Neutrófilos , Neutrófilos , Quimiocinas , Peptídeo Hidrolases
7.
Polymers (Basel) ; 15(15)2023 Aug 07.
Artigo em Inglês | MEDLINE | ID: mdl-37571221

RESUMO

The joint form plays a vital role in the rapid assembly of precast bridge decks for steel-concrete composite bridges. Existing research primarily focuses on studying the shear performance of joints through direct shear tests, which is insufficient to fully reflect the mechanical behavior of joints under the constraint of prefabricated bridge deck panels during actual vehicular traffic. Considering situations such as vehicle loads and external forces acting on precast bridge decks, this study investigates the shear performance of epoxy joints under constraint through an improved shear test. The influence of constraint force, shear key details and interface defects on the shear performance of epoxy joints is investigated. The results reveal that the shear test method employed in this study can realistically reflect the shear performance of epoxy joints in precast bridge decks. Both active and passive constrained epoxy joint specimens exhibited no interface cracks, and their failure modes were identified as shear failure between mid-span supports. Compared with passive constraint, the shear-bearing capacity of epoxy joint specimens under active constraint was increased by 86.1~130.6%. Among the epoxy joint specimens with depth-height ratios of 15/110, 25/110, 35/110 and 45/110, the joint with a depth of 35 mm demonstrated the highest shear strength. Furthermore, the shear performance of epoxy joints significantly deteriorated when the interface defects exceeded 30%, resulting in the failure mode transforming from shear failure to interface failure.

8.
J Immunol ; 211(3): 462-473, 2023 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-37326485

RESUMO

Cell spreading is an initial and critical step in neutrophil adhesion and migration, leading to neutrophil recruitment to inflammatory tissues. Sideroflexin (Sfxn) family proteins are metabolite transporters located in the mitochondrial membrane. Recombinant SFXN5 protein is a citrate transporter in vitro; however, whether Sfxn5 regulates any cellular behavior or function remains unknown. In this study, we found that small interfering RNA transfection or morpholino injection achieving Sfxn5 deficiency in neutrophils significantly decreased neutrophil recruitment in mice and zebrafish, respectively. Sfxn5 deficiency impaired neutrophil spreading and spreading-associated cellular phenotypes, such as cell adhesion, chemotaxis, and ROS production. Actin polymerization is critical for neutrophil spreading, and we found that actin polymerization in spreading neutrophils was partially inhibited by Sfxn5 deficiency. Mechanistically, we observed that the levels of cytosolic citrate and its downstream metabolic products, acetyl-CoA and cholesterol, were decreased in Sfxn5-deficient neutrophils. The levels of phosphatidylinositol 4,5-bisphosphate (PI(4,5)P2), a mediator for the regulation of actin polymerization by cholesterol, were reduced in the plasma membrane of Sfxn5-deficient neutrophils. Exogenous supplementation with citrate or cholesterol partially reversed the reduction in PI(4,5)P2 levels, defective neutrophil actin polymerization, and cell spreading. Altogether, we demonstrated that Sfxn5 maintains cytosolic citrate levels and ensures the synthesis of sufficient cholesterol to promote actin polymerization in a PI(4,5)P2-dependent manner during neutrophil spreading, which is essential for the eventual inflammatory recruitment of neutrophils. Our study revealed the importance of Sfxn5 in neutrophil spreading and migration, thus identifying, to our knowledge, for the first time, the physiological cellular functions of the Sfxn5 gene.


Assuntos
Actinas , Neutrófilos , Animais , Camundongos , Actinas/metabolismo , Neutrófilos/metabolismo , Ácido Cítrico/metabolismo , Peixe-Zebra/metabolismo , Polimerização , Colesterol/metabolismo
9.
Hematology ; 28(1): 2225341, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37335206

RESUMO

OBJECTIVE: The lives and safety of humans are significantly threatened by acute myeloid leukemia (AML), which is proven to be the most prevalent acute leukemia. This work is therefore intended to investigate and analyze the expressions of miR-361-3p and Histone Lysine Methyltransferase 2A (KMT2A) in tissues and cell lines of AML and identify an advanced and novel target for the therapy of AML. METHODS: The qRT-PCR and western blot assays were conducted to find expressions of miR-361-3p/KMT2A in AML PB and cell lines. After then, tests using CCK-8 and EdU were run to see how KMT2A affected the growth of AML cells. Transwell migration and invasion assay was conducted to evaluate KMT2A's contribution to the migration and invasion of AML cells. ENCORI and miRWalk predicted the association between KMT2A and miR-361-3p, and the dual-luciferase reporter experiment verified it. Furthermore, rescue studies were used to ascertain how KMT2A affected the miR-361-3p-regulated AML cells' abilities to proliferate, migrate, and invade. RESULTS: miR-361-3p was poorly expressed while KMT2A was abundantly expressed. Additionally, KMT2A downregulation prevented AML cells from proliferating. PCNA and Ki-67 protein levels fell when KMT2A was silent. Furthermore, AML cells' motility, invasion, and metastasis were inhibited by low KMT2A expression. KMT2A was also identified as a direct target of miR-361-3p and negatively correlated with miR-361-3p. Finally, the over-expression of KMT2A partially reversed the inhibitory effects of up-regulation of miR-361-3p. CONCLUSION: A potential therapeutic candidate target for the treatment of AML may be miR-361-3p/KMT2A.


Assuntos
Leucemia Mieloide Aguda , MicroRNAs , Humanos , MicroRNAs/genética , MicroRNAs/metabolismo , Linhagem Celular Tumoral , Proliferação de Células , Leucemia Mieloide Aguda/tratamento farmacológico , Regulação para Cima , Apoptose
10.
Small ; 19(29): e2300411, 2023 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-37029576

RESUMO

The introduction of electrolyte additives is one of the most potential strategies to improve the performance of potassium metal batteries (PMBs). However, designing an additive that can alter the K+ solvation shell and essentially inhibit K dendrite remains a challenge. Herein, the amyl-triphenyl-phosphonium bromide was introduced as an additive to build a stable solid electrolyte interphase layer. The amyl-TPP cations can form a cation shielding layer on the metal surface during the nucleation stage, preventing K+ from gathering at the tip to form K dendrites. Besides, the cations can be preferentially reduced to form Kx Py with fast K+ transport kinetics. The Br- anions, as Lewis bases with strong electronegativity, can not only coordinate the Lewis acid pentafluoride to inhibit the formation of HF, but also change the K+ solvation structure to reduce solvent molecules in the first solvation structure. Therefore, the symmetrical battery exhibits a low deposition overpotential of 123 mV at 0.1 mA cm-2 over 4200 h cycle life. The full battery, paried with a perylene-tetracarboxylic dianhydride (PTCDA) cathode, possesses a cycle life of 250 cycles at 2 C and 81.9% capacity retention. This work offers a reasonable electrolyte design to obtain PMBs with long-term stablity and safety.

11.
Small ; 19(32): e2300854, 2023 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-37060230

RESUMO

The construction of conductive scaffolds is demonstrated to be an ideal strategy to alleviate the volume expansion and dendrite growth of K metal anodes. Nevertheless, the heterogeneous top-bottom deposition behavior caused by incompatible electronic/ionic conductivity of three-dimensional (3D) skeleton severely hinders its application. Here, a K2 Se/Cu conducting layer is fabricated on the Cu foam so as to enhance ionic transport and weaken electronic conductivity of the skeleton. Then, an excellent simultaneous deposition behavior of K metal inside the host is obtained for the first time via tuning fast ionic transport and low electronic conductivity. The simultaneous deposition mode can not only utilize the entire 3D structure to accommodate the volume expansion during K deposition but also avoid the formation of K dendrites at high current and ultra-low temperature. Consequently, the symmetric cells present a long cycle lifespan over 1000 h with a low deposition overpotential of 80 mV at 1 mA cm-2 . Furthermore, the full cell matching with the perylene-tetracarboxylic dianhydride (PTCDA) cathode presents an outstanding cycle lifespan over 600 cycles at 5 C at -20°C. The proposed simultaneous deposition strategy provides a new design direction for the construction of dendrite-free K metal anodes.

12.
Bioengineering (Basel) ; 10(3)2023 Mar 14.
Artigo em Inglês | MEDLINE | ID: mdl-36978748

RESUMO

Currently, the assessment of process robustness is often time-consuming, labor-intensive, and material-intensive using process characterization studies. Therefore, a simple and time-saving method is highly needed for the biopharmaceutical industry. Apoptosis is responsible for 80% of Chinese hamster ovary (CHO) cell deaths and affects the robustness of the cell culture process. This study's results showed that a more robust process can support cells to tolerate apoptosis for a longer time, suggesting that the robustness of the process could be judged by the ability of cells to resist apoptosis. Therefore, it is necessary to establish a rapid method to detect the apoptosis of CHO cells. In trying to establish a new method for detecting apoptosis in large-scale cell cultures, glucose withdrawal was studied, and the results showed that CHO cells began to apoptose after glucose was consumed. Then, the concentration of extracellular potassium increased, and a prolongation of apoptosis time was observed. Further study results showed that the process with poor robustness was associated with a higher proportion of apoptosis and extracellular potassium concentration, so potassium could be used as a biochemical index of apoptosis. The strategy we present may be used to expedite the assessment of process robustness to obtain a robust cell culture process for other biologics.

13.
Plant Dis ; 107(9): 2784-2791, 2023 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-36802296

RESUMO

Seeds play a critical role in the production of American ginseng. Seeds are also one of the most important media for the long-distant dissemination and the crucial way for pathogen survival. Figuring out the pathogens carried by seeds is the basis for effective management of seedborne diseases. In this paper, we tested the fungi carried by the seeds of American ginseng from the main production areas of China using incubation and highly throughput sequencing methods. The seed-carried rates of fungi in Liuba, Fusong, Rongcheng, and Wendeng were 100, 93.8, 75.2, and 45.7%, respectively. Sixty-seven fungal species, which belonged to 28 genera, were isolated from the seeds. Eleven pathogens were identified from the seed samples. Among the pathogens, Fusarium spp. were found in all of the seed samples. The relative abundance of Fusarium spp. in the kernel was higher than that in the shell. Alpha index showed that the fungal diversity between seed shell and kernel differed significantly. Nonmetric multidimensional scaling analysis revealed that the samples from different provinces and between seed shell and kernel were distinctly separated. The inhibition rates of four fungicides to seed-carried fungi of American ginseng were 71.83% for Tebuconazole SC, 46.67% for Azoxystrobin SC, 46.08% for Fludioxonil WP, and 11.11% for Phenamacril SC. Fludioxonil, a conventional seed treatment agent, showed a low inhibitory effect on seed-carried fungi of American ginseng.


Assuntos
Fungicidas Industriais , Fusarium , Panax , Endófitos/genética , Fusarium/genética , Fungicidas Industriais/farmacologia , Sementes/microbiologia , Panax/microbiologia
14.
Front Med (Lausanne) ; 10: 1337403, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-38264034

RESUMO

Background: Myoglobin is an important biomarker for monitoring critically ill patients. However, the relationship between its dynamic changes and prognosis remains unclear. Methods: We retrospectively enrolled 11,218 critically ill patients from a general and surgical intensive care unit (ICU) of a tertiary hospital between June 2016 and May 2020. Patients with acute cardiovascular events, cardiac and major vascular surgeries, and rhabdomyolysis were excluded. To investigate the early myoglobin distribution, the critically ill patients were stratified according to the highest myoglobin level within 48 h after ICU admission. Based on this, the critically ill patients with more than three measurements within 1 week after ICU admission were included, and latent class trajectory modeling was used to classify the patients. The characteristics and outcomes were compared among groups. Sensitivity analysis was performed to exclude patients who had died within 72 h after ICU admission. Restricted mean survival time regression model based on pseudo values was used to determine the 28-day relative changes in survival time among latent classes. The primary outcome was evaluated with comparison of in-hospital mortality among each Trajectory group, and the secondary outcome was 28-day mortality. Results: Of 6,872 critically ill patients, 3,886 (56.5%) had an elevated myoglobin level (≥150 ng/mL) at admission to ICU, and the in-hospital mortality significantly increased when myoglobin level exceeded 1,000 µg/mL. In LCTM, 2,448 patients were unsupervisedly divided into four groups, including the steady group (n = 1,606, 65.6%), the gradually decreasing group (n = 523, 21.4%), the slowly rising group (n = 272, 11.1%), and the rapidly rising group (n = 47, 1.9%). The rapidly rising group had the largest proportion of sepsis (59.6%), the highest median Sequential Organ Failure Assessment (SOFA) score (10), and the highest in-hospital mortality (74.5%). Sensitivity analysis confirmed that 98.2% of the patients were classified into the same group as in the original model. Compared with the steady group, the rapidly rising group and the slowly rising group were significantly related to the reduction in 28-day survival time (ß = -12.08; 95% CI -15.30 to -8.86; ß = -4.25, 95% CI -5.54 to -2.97, respectively). Conclusion: Elevated myoglobin level is common in critically ill patients admitted to the ICU. Dynamic monitoring of myoglobin levels offers benefit for the prognosis assessment of critically ill patients.

15.
Polymers (Basel) ; 14(7)2022 Mar 28.
Artigo em Inglês | MEDLINE | ID: mdl-35406238

RESUMO

Application of ultra-high-performance concrete (UHPC) in joints can improve the impact resistance, crack resistance, and durability of structures. In this paper, the direct shear performance of ultra-high-performance concrete (UHPC) adhesive joints was experimentally studied. Twenty-four direct shear loading tests of UHPC adhesive joints were carried out considering different interface types and constraint states. The failure modes and load-slip curves of different interfaces were studied. Results indicated that passive confinement could enhance the strength and ductility of the interface; the average ultimate bearing capacity of the smooth, rough, grooved, and keyway specimens with passive restraint were, respectively, increased by 11.92%, 8.91%, 11.93%, and 17.766% compared with the unrestrained ones. The passive constraint force changes with the loading and finally tends to be stable. The epoxy adhesive has high reliability as a coating for the UHPC interface. The adhesive layer is not cracked before the failure of the specimen, which is also different from the common failure mode of adhesive joints. Failure of all specimens occurred in the UHPC layer, and the convex part of the groove interface shows the UHPC matrix peeling failure; the keyway interface is the shear damage of the key-tooth root, and the rest of the keyway showed UHPC surface peeling failure. According to the failure mode, the shear capacity of UHPC keyway adhesive joints under passive restraint is mainly provided by the shear resistance of key teeth, the friction force of the joint surface, and the bonding force of the UHPC surface. The friction coefficient was determined based on the test results, and the high-precision fitting formula between the shear strength of the UHPC surface and the passive constraint force was established. According to the Mohr stress circle theory, the proposed formula for direct shear strength of UHPC bonded joints under passive constraint was established. The average ratio of the proposed UHPC adhesive joint calculation formula to the test results was 0.99, and the standard deviation was 0.027.

16.
J Colloid Interface Sci ; 615: 1-9, 2022 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-35124497

RESUMO

High-energy-density lithium-rich Li1.2Ni0.13Co0.13Mn0.54O2 is regarded as one of the most promising cathode materials for lithium-ion batteries. However, its practical application is restricted by critical kinetics drawbacks and poor low-temperature electrochemical performances. In this research, Li1.2Ni0.13Co0.13Mn0.54O2 submicron particles coated by a Li7La3Zr2O12 (LLZO) layer and co-doped by La/Zr cations has been fabricated via a facile one-pot sol-gel technique and subsequent heat treatment. The coating LLZO layer with a few nanometers is able to build a rapid lithium-ion transport channel for adjacent particles and suppress severe side reactions between active material and the electrolyte. Moreover, large-radius La/Zr cations co-doping can broaden the diffusion paths of lithium ions, hinder the detrimental structural transformation, and improve the electrochemical structure stability of the cathode during repeated cycles. Owing to numerous merits from this multifunctional surface modification strategy, the modified Li1.2Ni0.13Co0.13Mn0.54O2 composite exhibits the significantly decreased interface impedance, enhanced Li+ diffusion kinetics and mitigated phase transformation, as well as excellent low-temperature electrochemical performance. It can contribute ultrahigh capacities of 173.8 mAh g-1 at -10 ℃ and 134.1 mAh g-1 at -20 ℃, respectively, displaying great application prospects of Li-rich cathode materials.

17.
Environ Sci Pollut Res Int ; 29(26): 40041-40052, 2022 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-35112246

RESUMO

The photocatalytic properties of Zn/Co zeolite imidazolate frameworks (ZIF-ZnCo) prepared by various Zn/Co ratio are of significantly diversity due to the morphology structure of the ZIF-ZnCo. Thereinto, the prepared ZIF-ZnCO-8:1 is excellent capability by virtue of its 3D cross-shaped structure. Spectral test results show that as-prepared novel 3D cross-shaped ZIF-ZnCo has a lower recombination rate of electron and hole pairs than the lamellar and dodecahedral, thus improving the photocatalytic ability. The photocatalytic ability of 3D cross-shaped ZIF-ZnCo was carefully investigated for removing mixed solution of Congo Red (CR) and Cr(VI). The photocatalytic reduction ability of 3D cross-shaped ZIF-ZnCo was 22% higher than ZIF-8 for Cr(VI). Meanwhile, CR was altogether removed at dark processing and Cr(VI) was removed 70% after dark processing 120 min and photocatalytic 240 min. Therefore, the high adsorption and photocatalytic capacity denote the potential application of 3D cross-shaped ZIF-ZnCo.


Assuntos
Zeolitas , Cromo/química , Vermelho Congo , Zeolitas/química , Zinco
18.
ACS Appl Mater Interfaces ; 14(2): 2930-2938, 2022 Jan 19.
Artigo em Inglês | MEDLINE | ID: mdl-34995450

RESUMO

The construction of three-dimensional lithiophilic hosts is one of the most effective approaches for achieving the uniform nucleation and alleviating the volume changes of the Li metal. Unfortunately, some lithiophilic materials suffer from severe mechanical degradation resulting from the large volume expansion during lithiation, which causes a heterogeneous Li deposition. Herein, a low-nucleation-barrier Cu3Sn alloy layer on a carbon paper (Cu3Sn/CP) is constructed by a facile co-electrodeposition method for the Li anode framework. Density functional theory calculations show that the Cu3Sn alloy has a higher binding energy (-2.31 eV) than pure Sn (-1.97 eV) due to the electron-deficient state of Sn in the alloy phase, which enables the lithiophilic Sn to have increased affinity for Li. Additionally, the uniformly distributed Cu particles can evenly disperse the electric field on the surface of the carbon fiber and act as a "metal barrier" to inhibit the volume expansion of the Sn particles during lithiation, thereby enhancing the electrochemical stability of the alloy modification layer. As a result, the Cu3Sn/CP anode framework exhibits an exceptionally low nucleation overpotential (∼10 mV), a high and steady Coulombic efficiency (>98.5% for more than 200 cycles), and a long lifespan up to 1150 h. The full cells with LiFePO4 as a cathode show favorable cycling performance at 1 C with a capacity retention rate of 95.2%. The construction of the Cu3Sn alloy layer in this work sheds light on the design of a high-stability lithiophilic host for the dendrite-free Li metal anode.

19.
ACS Appl Mater Interfaces ; 14(1): 900-909, 2022 Jan 12.
Artigo em Inglês | MEDLINE | ID: mdl-34958195

RESUMO

The inevitable problem of dendrites growth has hampered the further development of K metal anodes. Constructing a three-dimensional anode framework and potassiophilic nanocoating is an effective way to enlarge the specific surface area, reduce the local current density, and inhibit the formation of K dendrites. However, the effects of the electrochemically active surface area (ECSA) of the framework on deposition behavior have not been clarified. Hence, SnS2 nanosheets with different sizes are loaded on the surface of carbon paper (SnS2@CP) to improve the potassiophilicity and realize dendrite-free K-metal anodes. Experiments reveal that the size of SnS2 nanosheets would determine the ECSA of the framework, while the ECSA reveals the relative sizes of specific surface areas of frameworks. Excessive or limited specific surface areas will cause morphological collapse or weak potassiophilicity during potassiation, respectively, thus leading to high nucleation overpotential. The moderate specific surface area and abundant and stable potassiophilic sites prompt the SnS2@CP framework to achieve uniform electrodeposition of K. A low nucleation overpotential of 11.2 mV and a cycle life of more than 800 h are exhibited at a current density of 0.25 mA cm-2, indicating the directional strategy for stable and safe K metal anodes.

20.
J Colloid Interface Sci ; 611: 215-223, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-34952274

RESUMO

As a kind of negative electrode material for sodium-ion batteries (SIBs), tin-based active compounds have attracted numerous research efforts in recent years due to relatively high theoretical capacity. However, sluggish reaction kinetics for large-radius sodium ions hinders the practical application of layered tin-based anodes such as tin disulfide (SnS2) in SIBs. In this study, polyethylene glycol (PEG) is introduced as an intercalant and reduced graphene oxide (rGO) is utilized as the substrate to prepare a novel PEG-SnS2/rGO composite with expanded layer spacing (0.921 nm) through a facile hydrothermal process. SnS2 flakes in a size range of 50-100 nm are uniformly grown on the graphene sheet, the CS covalent bonding demonstrates a tight connection between the active SnS2 particles and the graphene skeleton, which is conductive to convenient charge transfer during the electrochemical process. Owing to the significantly improved sodium ions transport kinetics and fast electronic conductive network, the PEG-SnS2/rGO composite presents a high capacitance contribution of 90.69% at a scan rate of 0.6 mV s-1. It delivers a high reversible capacity of 960.6 mAh g-1 at 0.1 A g-1, good cycling performance with 770 mAh g-1 remained after 100 charge/discharge cycles, and excellent rate capability with an ultrahigh capacity of 720 mAh g-1 at 5 A g-1. This work provides new insights into the design of a kinetically favorable anode material for SIBs.

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