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1.
J Colloid Interface Sci ; 662: 183-191, 2024 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-38341941

RESUMO

Modulating the electronic structure of platinum (Pt) through a support is an important strategy for enhancing its electrocatalytic properties. In this work, to explore the impact of support electronegativity on Pt's catalytic activity for hydrogen evolution, we chose diverse metals with varying electronegativities that are stable in acidic solutions, such as titanium (Ti), molybdenum (Mo), and tungsten (W), as supports. Ti is the optimal support according to density functional theory (DFT) calculations. As expected, the Pt@Ti catalyst demonstrated remarkable efficiency in the hydrogen evolution reaction (HER), displaying a minimal overpotential of 13 mV at -10 mA cm-2, a Tafel slope of 34.5 mV dec-1, and sustained durability over 110 h in a 0.5 M H2SO4 solution. To unravel the metal-support interaction (MSI) between Pt and Ti, a comprehensive exploration encompassing both experimental investigations and DFT calculations was undertaken. The results elucidate that the outstanding HER performance of Pt@Ti stems from robust synergies forged between Pt and Ti atoms within the Ti support. This work not only furnishes a technique for producing electrocatalysts with superior efficiency and stability but also streamlines the process of choosing the most appropriate metal support. Moreover, it enhances comprehension of the interaction between Pt and the metal support.

2.
Fish Shellfish Immunol ; 147: 109443, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38354964

RESUMO

The tumor necrosis factor (TNF) receptor-associated factor (TRAF) family has been reported to be involved in many immune pathways. In a previous study, we identified 5 TRAF genes, including TRAF2, 3, 4, 6, and 7, in the bay scallop (Argopecten irradians, Air) and the Peruvian scallop (Argopecten purpuratus, Apu). Since TRAF6 is a key molecular link in the TNF superfamily, we conducted a series of studies targeting the TRAF6 gene in the Air and Apu scallops as well as their hybrid progeny, Aip (Air ♀ × Apu ♂) and Api (Apu ♀ × Air ♂). Subcellular localization assay showed that the Air-, Aip-, and Api-TRAF6 were widely distributed in the cytoplasm of the human embryonic kidney cell line (HEK293T). Additionally, dual-luciferase reporter assay revealed that among TRAF3, TRAF4, and TRAF6, only the overexpression of TRAF6 significantly activated NF-κB activity in the HEK293T cells in a dose-dependent manner. These results suggest a crucial role of TRAF6 in the immune response in Argopecten scallops. To investigate the specific immune mechanism of TRAF6 in Argopecten scallops, we conducted TRAF6 knockdown using RNA interference. Transcriptomic analyses of the TRAF6 RNAi and control groups identified 1194, 2403, and 1099 differentially expressed genes (DEGs) in the Air, Aip, and Api scallops, respectively. KEGG enrichment analyses revealed that these DEGs were primarily enriched in transport and catabolism, amino acid metabolism, peroxisome, lysosome, and phagosome pathways. Expression profiles of 28 key DEGs were confirmed by qRT-PCR assays. The results of this study may provide insights into the immune mechanisms of TRAF in Argopecten scallops and ultimately benefit scallop breeding.


Assuntos
Pectinidae , Fator 6 Associado a Receptor de TNF , Humanos , Animais , Fator 6 Associado a Receptor de TNF/metabolismo , Células HEK293 , Fator 2 Associado a Receptor de TNF/metabolismo , Receptores do Fator de Necrose Tumoral , Pectinidae/genética , Fator 4 Associado a Receptor de TNF/metabolismo
3.
Nanomaterials (Basel) ; 13(23)2023 Nov 22.
Artigo em Inglês | MEDLINE | ID: mdl-38063698

RESUMO

Hard carbon is regarded as one of the greatest potential anode materials for sodium-ion batteries (SIBs) because of its affordable price and large layer spacing. However, its poor initial coulombic efficiency (ICE) and low specific capacity severely restrict its practical commercialization in SIBs. In this work, we successfully constructed abundant oxygen-containing functional groups in hard carbon by using pre-oxidation anthracite as the precursor combined with controlling the carbonization temperature. The oxygen-containing functional groups in hard carbon can increase the reversible Na+ adsorption in the slope region, and the closed micropores can be conducive to Na+ storage in the low-voltage platform region. As a result, the optimal sample exhibits a high initial reversible sodium storage capacity of 304 mAh g-1 at 0.03 A g-1, with an ICE of 67.29% and high capacitance retention of 95.17% after 100 cycles. This synergistic strategy can provide ideas for the design of high-performance SIB anode materials with the intent to regulate the oxygen content in the precursor.

4.
Nanomicro Lett ; 15(1): 227, 2023 Oct 13.
Artigo em Inglês | MEDLINE | ID: mdl-37831203

RESUMO

Efficient electrocatalysts are crucial for hydrogen generation from electrolyzing water. Nevertheless, the conventional "trial and error" method for producing advanced electrocatalysts is not only cost-ineffective but also time-consuming and labor-intensive. Fortunately, the advancement of machine learning brings new opportunities for electrocatalysts discovery and design. By analyzing experimental and theoretical data, machine learning can effectively predict their hydrogen evolution reaction (HER) performance. This review summarizes recent developments in machine learning for low-dimensional electrocatalysts, including zero-dimension nanoparticles and nanoclusters, one-dimensional nanotubes and nanowires, two-dimensional nanosheets, as well as other electrocatalysts. In particular, the effects of descriptors and algorithms on screening low-dimensional electrocatalysts and investigating their HER performance are highlighted. Finally, the future directions and perspectives for machine learning in electrocatalysis are discussed, emphasizing the potential for machine learning to accelerate electrocatalyst discovery, optimize their performance, and provide new insights into electrocatalytic mechanisms. Overall, this work offers an in-depth understanding of the current state of machine learning in electrocatalysis and its potential for future research.

5.
Sci Rep ; 13(1): 13931, 2023 08 25.
Artigo em Inglês | MEDLINE | ID: mdl-37626167

RESUMO

Plant-derived nanovesicles (NVs) and extracellular vesicles (EVs) are the next generation of nanocarrier platforms for biotherapeutics and drug delivery. EVs exist not only in the extracellular space, but also within the cell wall. Due to the limitations of existing isolation methods, the EVs extraction efficiency is low, and a large amount of plant material is wasted, which is of concern for rare and expensive medicinal plants. We proposed and validated a novel method for isolation of plant EVs by enzyme degradation of the plant cell wall to release the EVs. The released EVs can easily be collected. The new method was used for extraction of EVs from the roots of Morinda officinalis (MOEVs). For comparison, nanoparticles from the roots (MONVs) were extracted using the grinding method. The new method yielded a greater amount of MOEVs, and the vesicles had a smaller diameter compared to MONVs. Both MOEVs and MONVs were readily absorbed by endothelial cells without cytotoxic effect and promoted the expression of miR-155. The promotion of miR-155 by MOEVs was dose-dependent. More importantly, we found that MOEVs and MONVs were enriched toward bone tissue. These results support our hypothesis that EVs in plants could be efficiently extracted by enzymatic cell wall digestion and confirm the potential of MOEVs as therapeutic agents and drug carriers.


Assuntos
Vesículas Extracelulares , MicroRNAs , Células Endoteliais , Espaço Extracelular , Osso e Ossos
6.
Mar Biotechnol (NY) ; 25(6): 891-906, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37632589

RESUMO

The interspecific hybrid scallops generated from the hermaphroditic bay scallops (Argopecten irradians) and Peruvian scallops (Argopecten purpuratus) showed significant heterosis in growth. However, its sterility limits large-scale hybridization and hinders the development of the scallop breeding industry. Hybrid sterility is regulated by plenty of genes and involves a range of biochemical and physiological transformations. In this study, whole-genome re-sequencing and transcriptomic analysis were performed in sterile and fertile hybrid scallops. The potential genetic variations and abnormally expressed genes were detected to explore the mechanism underlying hybrid sterility in hermaphroditic Argopecten scallops. Compared with fertile hybrids, 24 differentially expressed genes (DEGs) with 246 variations were identified to be related to fertility regulation, which were mainly enriched in germarium-derived egg chamber formation, spermatogenesis, spermatid development, mismatch repair, mitotic and meiotic cell cycles, Wnt signaling pathway, MAPK signaling pathway, calcium modulating pathway, and notch signaling pathway. Specifically, variation and abnormal expression of these genes might inhibit the progress of mitosis and meiosis, promote cell apoptosis, and impede the genesis and maturation of gametes in sterile hybrid scallops. Eleven DEGs (XIAP, KAZN, CDC42, MEIS1, SETD1B, NOTCH2, TRPV5, M- EXO1, GGT1, SBDS, and TBCEL) were confirmed by qRT-PCR validation. Our findings may enrich the determination mechanism of hybrid sterility and provide new insights into the use of interspecific hybrids for extensive breeding.


Assuntos
Infertilidade , Pectinidae , Masculino , Animais , Transcriptoma , Perfilação da Expressão Gênica , Hibridização Genética , Pectinidae/genética , Pectinidae/metabolismo
7.
Mar Biotechnol (NY) ; 25(5): 701-717, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37548862

RESUMO

DNA methylation is an important epigenetic modification factor in regulating fertility. Corresponding process remains poorly investigated in hermaphroditic scallops. The interspecific F1 hybrids between the hermaphroditic bay scallops (Argopecten irradians) and Peruvian scallops (Argopecten purpuratus) exhibited significant heterosis in yield, but sterility in hybrids obstructs the utilization of the genetic resources. However, the determination mechanism of hybrid sterility in the hermaphroditic Argopecten scallops is still unclear. In this study, the effect of DNA methylation in the hybrid sterility of hermaphroditic Argopecten scallops was explored. The results showed that the mean methylation level was higher in sterile hybrids than fertile hybrids, especially on chromosome 11 of the paternal parent. A total of 61,062 differentially methylated regions (DMRs) were identified, containing 3619 differentially methylated genes (DMGs) and 1165 differentially methylated promoters that are located in the DMRs of CG sequence context. The hyper-methylated genes were enriched into five KEGG pathways, including ubiquitin-mediated proteolysis, ECM-receptor interaction, non-homologous end-joining, notch signaling, and the mismatch repair pathways. The DMGs might induce hybrid sterility by inhibition of oogenesis and egg maturation, induction of apoptosis, increased ROS, and insufficient ATP supply. Our results would enrich the determination mechanism of hybrid sterility and provide new insights into the utilization of the genetic resources of the interspecific hybrids.


Assuntos
Infertilidade , Pectinidae , Animais , Metilação de DNA , Fertilidade/genética , Vigor Híbrido , Pectinidae/genética
8.
Molecules ; 28(11)2023 May 23.
Artigo em Inglês | MEDLINE | ID: mdl-37298762

RESUMO

Despite having ultra-high theoretical specific capacity and theoretical energy density, lithium-sulfur (Li-S) batteries suffer from their low Coulombic efficiency and poor lifespan, and the commercial application of Li-S batteries is seriously hampered by the severe "shuttle effect" of lithium polysulfides (LiPSs) and the large volume expansion ratio of the sulfur electrode during cycling. Designing functional hosts for sulfur cathodes is one of the most effective ways to immobilize the LiPSs and improve the electrochemical performance of a Li-S battery. In this work, a polypyrrole (PPy)-coated anatase/bronze TiO2 (TAB) heterostructure was successfully prepared and used as a sulfur host. Results showed that the porous TAB could physically adsorb and chemically interact with LiPSs during charging and discharging processes, inhibiting the LiPSs' shuttle effect, and the TAB's heterostructure and PPy conductive layer are conducive to the rapid transport of Li+ and improve the conductivity of the electrode. By benefitting from these merits, Li-S batteries with TAB@S/PPy electrodes could deliver a high initial capacity of 1250.4 mAh g-1 at 0.1 C and show an excellent cycling stability (the average capacity decay rate was 0.042% per cycle after 1000 cycles at 1 C). This work brings a new idea for the design of functional sulfur cathodes for high-performance Li-S battery.


Assuntos
Lítio , Polímeros , Pirróis , Enxofre
9.
Molecules ; 28(9)2023 Apr 27.
Artigo em Inglês | MEDLINE | ID: mdl-37175167

RESUMO

Fe-based sulfides are a promising type of anode material for sodium-ion batteries (SIBs) due to their high theoretical capacities and affordability. However, these materials often suffer from issues such as capacity deterioration and poor conductivity during practical application. To address these challenges, an N-doped Fe7S8 anode with an N, S co-doped porous carbon framework (PPF-800) was synthesized using a template-assisted method. When serving as an anode for SIBs, it delivers a robust and ultrafast sodium storage performance, with a discharge capacity of 489 mAh g-1 after 500 cycles at 5 A g-1 and 371 mAh g-1 after 1000 cycles at 30 A g-1 in the ether-based electrolyte. This impressive performance is attributed to the combined influence of heteroatomic doping and adjustable interface engineering. The N, S co-doped carbon framework embedded with Fe7S8 nanoparticles effectively addresses the issues of volumetric expansion, reduces the impact of sodium polysulfides, improves intrinsic conductivity, and stimulates the dominant pseudocapacitive contribution (90.3% at 2 mV s-1). Moreover, the formation of a stable solid electrolyte interface (SEI) film by the effect of uniform pore structure in ether-based electrolyte produces a lower transfer resistance during the charge-discharge process, thereby boosting the rate performance of the electrode material. This work expands a facile strategy to optimize the electrochemical performance of other metal sulfides.

10.
Fish Shellfish Immunol ; 135: 108702, 2023 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-36948367

RESUMO

Vibrio bacteria are often fatal to aquatic organisms and selection of Vibrio-resistant strains is warranted for aquaculture animals. In this study, we found that hybrids between bay scallops and Peruvian scallops exhibited significantly higher resistance to Vibrio challenge, but little is available on its mechanism. Interferon induced protein 44 (IFI44), a member of the type I interferon (IFN) family, plays an important role in the IFN immune response in invertebrates, which may also participate in the resistance to Vibrio in scallops. To explore the roles of IFI44 genes in the resistance to Vibrio, they were identified and characterized in the bay scallop (designated as AiIFI44), the Peruvian scallop (designated as ApIFI44), and their reciprocal hybrids (designated as AipIFI44 and ApiIFI44, respectively). Their open reading frame (ORF) sequences were all 1434 bp, encoding 477 amino acids, but with large variations among the four genes. The AipIFI44 and ApiIFI44 exhibited higher similarity with ApIFI44 than with AiIFI44. All four genes have a TLDc structural domain with significant variations in sequences among them. Predicted differences in conformation and posttranslational modifications may lead to altered protein activity. We further demonstrated that the AiIFI44, AipIFI44 and ApiIFI44 expressed in all the tested tissues, with the highest expression in the gills and hepatopancreas. In response to Vibrio anguillarum challenge, the profile of mRNA expression of IFI44 gene differed among the bay scallops and the two hybrids. In the bay scallops, it increased at 6 h but dramatically decreased after 12-48 h. However, the mRNA expression of both AipIFI44 and ApiIFI44 decreased at 6 h but continuously increased thereafter and reached the highest value at 48 h. The results in the present study suggest the immune responds of IFI44 in scallops and it may be related to the higher resistance to Vibrio bacterial in hybrids.


Assuntos
Pectinidae , Vibrio , Animais , Interferons/genética , Vibrio/fisiologia , RNA Mensageiro , Filogenia
11.
Fish Shellfish Immunol ; 135: 108675, 2023 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-36906048

RESUMO

The tumor necrosis factor receptor-related factor (TRAF) family has been reported to be involved in many immune pathways, such as TNFR, TLR, NLR, and RLR in animals. However, little is known about the roles of TRAF genes in the innate immune of Argopecten scallops. In this study, we first identified five TRAF genes, including TRAF2, TRAF3, TRAF4, TRAF6 and TRAF7, but not TRAF1 and TRAF5, from both the bay scallop A. irradians (Air) and the Peruvian scallop A. purpuratus (Apu). The phylogenetic analysis showed that the TRAF genes in Argopecten scallops (AiTRAF) belong to the branch of molluscan TRAF family, which lacks TRAF1 and TRAF5. Since TRAF6 is a key bridge factor in the tumor necrosis factor superfamily and plays an important role in innate and adaptive immunity, we cloned the ORFs of the TRAF6 gene in both A. irradians and A. purpuratus, as well as in two reciprocal hybrids (Aip for the hybrid Air × Apu and Api for the hybrid Apu × Air). Differences in conformational and post-translational modification resulted from the variation in amino acid sequences may cause differences in activity among them. Analysis of conserved motifs and protein structural domains revealed that AiTRAF contains typical structural domains similar to those of other mollusks and has the same conserved motifs. Tissue expression of TRAF in Argopecten scallops challenged by Vibrio anguillarum was examined by qRT-PCR. The results showed that AiTRAF were higher in gill and hepatopancreas. When challenged by Vibrio anguillarum, the expression of AiTRAF was significantly increased compared with the control group, indicating that AiTRAF may play an important role in the immunity of scallops. In addition, the expression of TRAF was higher in Api and Aip than in Air when challenged by Vibrio anguillarum, suggesting that TRAF may have contributed to the high resistance of Api and Aip to Vibrio anguillarum. The results of this study may provide new insights into the evolution and function of TRAF genes in bivalves and ultimately benefit scallop breeding.


Assuntos
Pectinidae , Vibrio , Animais , Filogenia , Vibrio/fisiologia , Sequência de Aminoácidos , Pectinidae/genética
12.
Adv Sci (Weinh) ; 10(9): e2206574, 2023 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-36683228

RESUMO

Transition metal oxides with high capacity still confront the challenges of low initial coulombic efficiency (ICE, generally <70%) and inferior cyclic stability for practical lithium-storage. Herein, a hollow slender carambola-like Li0.43 FeO1.51 with Fe vacancies is proposed by a facile reaction of Fe3+ -containing metal-organic frameworks with Li2 CO3 . Synthesis experiments combined with synchrotron-radiation X-ray measurements identify that the hollow structure is caused by Li2 CO3 erosion, while the formation of Fe vacancies is resulted from insufficient lithiation process with reduced Li2 CO3 dosage. The optimized lithium iron oxides exhibit remarkably improved ICE (from 68.24% to 86.78%), high-rate performance (357 mAh g-1 at 5 A g-1 ), and superior cycling stability (884 mAh g-1 after 500 cycles at 0.5 A g-1 ). Paring with LiFePO4 cathodes, the full-cells achieve extraordinary cyclic stability with 99.3% retention after 100 cycles. The improved electrochemical performances can be attributed to the synergy of structural characteristics and Fe vacancy engineering. The unique hollow structure alleviates the volume expansion of Li0.43 FeO1.51 , while the in situ generated Fe vacancies are powerful for modulating electronic structure with boosted Li+ transport rate and catalyze more Li2 O decomposition to react with Fe in the first charge process, hence enhancing the ICE of lithium iron oxide anode materials.

13.
ACS Omega ; 8(1): 1375-1388, 2023 Jan 10.
Artigo em Inglês | MEDLINE | ID: mdl-36643466

RESUMO

To investigate the effect of concentration of N2 and CO2 (0, 10, 20, 30, 40, and 50%) on the flame propagation characteristics of CH4/air premixed gases with stoichiometric ratios in variable cross-section ducts, experiments were conducted in four combinations of ducts at initial conditions of 298 K and 1 atm. The results show that the flame propagation velocity, propagation time, and overpressure are greater in the suddenly contracted duct than in the suddenly expanded duct if the dimensions of the ducts are kept constant. However, an increase in inert gas concentration leads to a decrease in flame propagation speed, an increase in flame propagation time, and changes in flame structure and pressure. "Tulip" flames appeared when a duct with a cross section of 100 mm × 100 mm was combined with a duct with a cross section of 70 mm × 70 mm, whether N2 or CO2 was added or what its concentration was. However, when a duct with a cross section of 140 mm × 140 mm was combined with a 70 mm × 70 mm duct, a "tulip" flame is formed only at a CO2 concentration of 50%. As the concentration of inert gas increases, the explosion pressure first decreases and then stabilizes, while the rate of pressure increase showed a monotonically decreasing trend. The explosion pressure is minimized when the concentration of CO2 and N2 is 30 and 40%, respectively.

14.
Nanoscale ; 14(39): 14575-14584, 2022 Oct 13.
Artigo em Inglês | MEDLINE | ID: mdl-36149683

RESUMO

Regulating the electronic structure plays a positive role in improving the ion/electron kinetics of electrode materials for lithium ion batteries (LIBs). Herein, an effective approach is demonstrated to achieve Ni/Mo2C hybrid nanoparticles embedded in porous nitrogen-doped carbon nanofibers (Ni/Mo2C/NC). Density functional theory calculations indicate that Ni can activate the interface of Ni/Mo2C by regulating the electronic structure, and accordingly improve the electron/Li-ion diffusion kinetics. The charge at the interface transfers from Ni atoms to Mo atoms on the surface of Mo2C, illustrating the formation of an interfacial electric field in Ni/Mo2C. The formed interfacial electric field in Ni/Mo2C can improve the intrinsic electronic conductivity, and reduce the Li adsorption energy and the Li+ diffusion barrier. Thus, the obtained Ni/Mo2C/NC shows an excellent high-rate capability of 344.1 mA h g-1 at 10 A g-1, and also displays a superior cyclic performance (remaining at 412.7 mA h g-1 after 1800 cycles at 2 A g-1). This work demonstrates the important role of electronic structure regulation by assembling hybrid materials and provides new guidance for future work on designing novel electrode materials for LIBs.

15.
Dalton Trans ; 51(33): 12620-12629, 2022 Aug 23.
Artigo em Inglês | MEDLINE | ID: mdl-35925026

RESUMO

The electronic structure regulation of electrode materials can improve the ion/electron kinetics, which is beneficial to the cyclic performance and rate capability for lithium ion batteries (LIBs). Herein, we propose a facile strategy to achieve a MoO2/Mo2C/C heterostructure with abundant oxygen vacancies. Density functional theory calculations indicate that the heterostructure of MoO2/Mo2C/C can significantly promote the Li+/charge transfer and reduce the Li adsorption energy, and the abundant oxygen vacancies in MoO2/Mo2C/C can improve the intrinsic electronic conductivity and reduce the Li+ diffusion barrier. Benefiting from the multiscale coordinated regulation, the obtained MoO2/Mo2C/C film exhibits outstanding high rate capability (454.7 mA h g-1 at 5 A g-1) and remarkable cyclic performance (retaining 569 mA h g-1 over 1000 cycles at 2 A g-1). The insightful findings in this study can shed light on the behavior of the electron/ion structure regulation by the heterostructure and oxygen vacancies, which can guide future studies on designing other electrode materials with high-performance lithium-ion storage.

16.
Chem Commun (Camb) ; 58(71): 9918-9921, 2022 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-35979752

RESUMO

Strong electronic metal-support interaction (EMSI) can tailor the electronic structure of electrocatalysts. Herein, Pt nanoparticles anchored on stainless mesh (SM) via EMSI engineering are reported, exhibiting excellent hydrogen production activity. Theoretical calculations demonstrate that the superior performance stems from the strong EMSI between Pt atoms and Fe atoms in SM.

17.
J Colloid Interface Sci ; 627: 862-871, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-35901565

RESUMO

Heterostructure engineering is an efficient strategy to synergisticallyimprove electrocatalytic activity. In this work, Ni/MoO2 heterojunction nanorods with porous structure self-supported on nickel foam (NF) are elaborately designed through a facile solution-evaporationmethod followed by a thermal reduction process. Prominently, the optimal electrocatalyst Ni/MoO2@NF-E delivers an exceptionally low overpotential of 19 mV at the current density of 10 mA cm-2 and a small Tafel slope of 52.3 mV dec-1 toward the hydrogen evolution reaction (HER) in alkaline solution. Concurrently, Ni/MoO2@NF-E also maintains excellent stability after 120 h of electrolysis or 5000 cyclic voltammetry cycles. The experimental and density functional theory (DFT) results indicate that the enhanced HER performance of Ni/MoO2@NF-E should be ascribed to the porous structure in the Ni/MoO2 nanorods providing more active catalytic site, the moderate Gibbs free energy of hydrogen adsorption (ΔGH*), as well as strong synergistic effect between Ni and MoO2. This work provides an efficient route for developing HER electrocatalysts in alkaline media.

18.
ACS Omega ; 6(44): 29609-29617, 2021 Nov 09.
Artigo em Inglês | MEDLINE | ID: mdl-34778632

RESUMO

Rational construction of anode material architecture to afford excellent cycling stability, fast rate capacity, and large specific capacity is essential to promote further development of lithium-ion batteries in commercial applications. In this work, we propose a facile strategy to anchor ultrafine ß-Mo2C nanoparticles in N-doped porous carbon skeleton (ß-Mo2C@NC) using a scalable salt-template method. The well-defined and abundant hierarchical porous structure of ß-Mo2C@NC can not only significantly enhance the electron/ion transfer but also markedly increase the specific surface area to effectively expose the electrochemically accessible active sites. Besides, the N-doped carbon matrix can turn the d-orbital electrons of the Mo to boost the electron transportation as well as distribute active sites to buffer the volume change of Mo2C and provide conductive pathways during discharge/charge cycles. As a result, the as-prepared ß-Mo2C@NC displays excellent lithium storage performance in terms of 1701.6 mA h g-1 at 0.1 A g-1 after 100 cycles and a large capacity of 816.47 mA h g-1 at 2.0 A g-1 after 500 cycles. The above results distinctly demonstrate that the ß-Mo2C@NC composite has potential application as anode materials in high-performance energy storage devices.

19.
Nanomaterials (Basel) ; 11(9)2021 Sep 11.
Artigo em Inglês | MEDLINE | ID: mdl-34578681

RESUMO

SiOx is considered as a promising anode for next-generation Li-ions batteries (LIBs) due to its high theoretical capacity; however, mechanical damage originated from volumetric variation during cycles, low intrinsic conductivity, and the complicated or toxic fabrication approaches critically hampered its practical application. Herein, a green, inexpensive, and scalable strategy was employed to fabricate NG/SiOx/NG (N-doped reduced graphene oxide) homogenous hybrids via a freeze-drying combined thermal decomposition method. The stable sandwich structure provided open channels for ion diffusion and relieved the mechanical stress originated from volumetric variation. The homogenous hybrids guaranteed the uniform and agglomeration-free distribution of SiOx into conductive substrate, which efficiently improved the electric conductivity of the electrodes, favoring the fast electrochemical kinetics and further relieving the volumetric variation during lithiation/delithiation. N doping modulated the disproportionation reaction of SiOx into Si and created more defects for ion storage, resulting in a high specific capacity. Deservedly, the prepared electrode exhibited a high specific capacity of 545 mAh g-1 at 2 A g-1, a high areal capacity of 2.06 mAh cm-2 after 450 cycles at 1.5 mA cm-2 in half-cell and tolerable lithium storage performance in full-cell. The green, scalable synthesis strategy and prominent electrochemical performance made the NG/SiOx/NG electrode one of the most promising practicable anodes for LIBs.

20.
Cell Rep ; 35(3): 109003, 2021 04 20.
Artigo em Inglês | MEDLINE | ID: mdl-33882311

RESUMO

It has been proposed that sound information is separately streamed into onset and offset pathways for parallel processing. However, how offset responses contribute to auditory perception remains unclear. Here, loose-patch and whole-cell recordings in awake mouse primary auditory cortex (A1) reveal that a subset of pyramidal neurons exhibit a transient "Off" response, with its onset tightly time-locked to the sound termination and its frequency tuning similar to that of the transient "On" response. Both responses are characterized by excitation briefly followed by inhibition, with the latter mediated by parvalbumin (PV) inhibitory neurons. Optogenetically manipulating sound-evoked A1 responses at different temporal phases or artificially creating phantom sounds in A1 further reveals that the A1 phasic On and Off responses are critical for perceptual discrimination of sound duration. Our results suggest that perception of sound duration is dependent on precisely encoding its onset and offset timings by phasic On and Off responses.


Assuntos
Potenciais de Ação/fisiologia , Percepção Auditiva/fisiologia , Potenciais Evocados Auditivos/fisiologia , Optogenética/métodos , Reconhecimento Fisiológico de Modelo/fisiologia , Células Piramidais/fisiologia , Estimulação Acústica/métodos , Animais , Córtex Auditivo/anatomia & histologia , Córtex Auditivo/fisiologia , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Eletrodos Implantados , Feminino , Expressão Gênica , Genes Reporter , Proteínas Luminescentes/genética , Proteínas Luminescentes/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Técnicas de Patch-Clamp , Som , Vigília/fisiologia
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