Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 359
Filtrar
Más filtros

País/Región como asunto
Tipo del documento
Intervalo de año de publicación
1.
Mol Cell ; 67(4): 566-578.e10, 2017 Aug 17.
Artículo en Inglés | MEDLINE | ID: mdl-28803781

RESUMEN

50 years ago, Vincent Allfrey and colleagues discovered that lymphocyte activation triggers massive acetylation of chromatin. However, the molecular mechanisms driving epigenetic accessibility are still unknown. We here show that stimulated lymphocytes decondense chromatin by three differentially regulated steps. First, chromatin is repositioned away from the nuclear periphery in response to global acetylation. Second, histone nanodomain clusters decompact into mononucleosome fibers through a mechanism that requires Myc and continual energy input. Single-molecule imaging shows that this step lowers transcription factor residence time and non-specific collisions during sampling for DNA targets. Third, chromatin interactions shift from long range to predominantly short range, and CTCF-mediated loops and contact domains double in numbers. This architectural change facilitates cognate promoter-enhancer contacts and also requires Myc and continual ATP production. Our results thus define the nature and transcriptional impact of chromatin decondensation and reveal an unexpected role for Myc in the establishment of nuclear topology in mammalian cells.


Asunto(s)
Linfocitos B/metabolismo , Ciclo Celular , Núcleo Celular/metabolismo , Ensamble y Desensamble de Cromatina , Cromatina/metabolismo , Histonas/metabolismo , Activación de Linfocitos , Proteínas Proto-Oncogénicas c-myc/metabolismo , Acetilcoenzima A/metabolismo , Acetilación , Adenosina Trifosfato/metabolismo , Animales , Linfocitos B/inmunología , Línea Celular , Cromatina/química , Cromatina/genética , Metilación de ADN , Epigénesis Genética , Genotipo , Histonas/química , Inmunidad Humoral , Metilación , Ratones Endogámicos C57BL , Ratones Noqueados , Conformación de Ácido Nucleico , Fenotipo , Dominios y Motivos de Interacción de Proteínas , Procesamiento Proteico-Postraduccional , Proteínas Proto-Oncogénicas c-myc/química , Proteínas Proto-Oncogénicas c-myc/genética , Imagen Individual de Molécula , Relación Estructura-Actividad , Factores de Tiempo , Transcripción Genética
2.
Genes Dev ; 31(17): 1795-1808, 2017 09 01.
Artículo en Inglés | MEDLINE | ID: mdl-28982762

RESUMEN

Transcription factor (TF)-directed enhanceosome assembly constitutes a fundamental regulatory mechanism driving spatiotemporal gene expression programs during animal development. Despite decades of study, we know little about the dynamics or order of events animating TF assembly at cis-regulatory elements in living cells and the long-range molecular "dialog" between enhancers and promoters. Here, combining genetic, genomic, and imaging approaches, we characterize a complex long-range enhancer cluster governing Krüppel-like factor 4 (Klf4) expression in naïve pluripotency. Genome editing by CRISPR/Cas9 revealed that OCT4 and SOX2 safeguard an accessible chromatin neighborhood to assist the binding of other TFs/cofactors to the enhancer. Single-molecule live-cell imaging uncovered that two naïve pluripotency TFs, STAT3 and ESRRB, interrogate chromatin in a highly dynamic manner, in which SOX2 promotes ESRRB target search and chromatin-binding dynamics through a direct protein-tethering mechanism. Together, our results support a highly dynamic yet intrinsically ordered enhanceosome assembly to maintain the finely balanced transcription program underlying naïve pluripotency.


Asunto(s)
Elementos de Facilitación Genéticos/genética , Regulación de la Expresión Génica/genética , Factores de Transcripción de Tipo Kruppel/genética , Células Madre Pluripotentes/fisiología , Animales , Sitios de Unión , Cromatina/metabolismo , Células Madre Embrionarias , Factor 4 Similar a Kruppel , Ratones , Factor 3 de Transcripción de Unión a Octámeros/metabolismo , Unión Proteica , Receptores de Estrógenos/metabolismo , Factores de Transcripción SOXB1/metabolismo , Factor de Transcripción STAT3/metabolismo , Factores de Transcripción/metabolismo
3.
Small ; : e2311782, 2024 Mar 18.
Artículo en Inglés | MEDLINE | ID: mdl-38497813

RESUMEN

With the development of electric vehicles, exploiting anode materials with high capacity and fast charging capability is an urgent requirement for lithium-ion batteries (LIBs). Borophene, with the merits of high capacity, high electronic conductivity and fast diffusion kinetics, holds great potential as anode for LIBs. However, it is difficult to fabricate for the intrinsic electron-deficiency of boron atom. Herein, heterogeneous-structured MoB2 (h-MoB2 ) with amorphous shell and crystalline core, is prepared by solid phase molten salt method. As demonstrated, crystalline core can encapsulate the honeycomb borophene within two adjacent Mo atoms, and amorphous shell can accommodate more lithium ions to strengthen the lithium storage capacity and diffusion kinetics. According to theoretical calculations, the lithium adsorption energy in MoB2 is about -2.7 eV, and the lithium diffusion energy barrier in MoB2 is calculated to be 0.199 eV, guaranteeing the enhanced adsorption capability and fast diffusion kinetic behavior of Li+ ions. As a result, h-MoB2 anode presents high capacity of 798 mAh g-1 at 0.1 A g-1 , excellent rate performance of 183 mAh g-1 at 5 A g-1 and long-term cyclic stability for 1200 cycles. This work may inspire ideas for the fabrication of borophene analogs and two-dimensional metal borides.

4.
Opt Lett ; 49(11): 2873-2876, 2024 Jun 01.
Artículo en Inglés | MEDLINE | ID: mdl-38824280

RESUMEN

In the space gravitational wave detection, numerous laser interferometer strategies have been proposed to reduce the complexity of traditional heterodyne interferometers. Previously, we proposed a novel interferometric strategy and simulated its effectiveness, called CAM (constant amplitude modulation) heterodyne interferometry. Compared with other methods, the CAM can introduce the OPT (optical pilot tone) for the common-mode noise rejection. In this paper, we present the first, to our knowledge, experimental verification of this technique. The experimental results indicate that OPT can successfully eliminate sampling jitter, enabling the corrected noise to meet the requirements of space gravitational wave detection. This provides a new approach for further optical optimization and noise elimination in the future.

5.
Chemistry ; 30(13): e202303424, 2024 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-38116816

RESUMEN

High-efficacy recycling of spent lithium cobalt oxide (LiCoO2 ) batteries is one of the key tasks in realizing a global resource security strategy due to the rareness of lithium (Li) and cobalt (Co) resources. However, it is of great significance to develop the innovative recycle methods for spent LiCoO2 , simultaneously realizing the efficient recovery of valuable elements and the regeneration of high-performance LiCoO2 . Herein, a novel strategy of regenerating LiCoO2 cathode is proposed, which involves the preparation of micro-spherical aluminum (Al)-doped lithium-lacked precursor (Li2x Co1-x-y Al2/3y CO3, remarked as "PLCAC") via ammonium bicarbonate coprecipitation. The comprehensive conditions affecting particle growth kinetics, morphology and particle size the has been investigated in detail by physical characterizations and electrochemical measurements. And the optimized Al-doped LiCoO2 materials with high-density sphericity (LiCo1-z Alz O2 , remarked as "LCAO") shows a high initial specific capacity of 161 mAh g-1 at 0.1 C and excellent capacity retention of 99.5 % within 100 cycles at 1 C in the voltage range of 2.8 to 4.3 V. Our work provides valuable insights into the featured design of LiCoO2 precursors and cathode materials from spent LiCoO2 batteries, potentially guaranteeing the high-efficacy recycling and utilization of strategic resources.

6.
Chemistry ; 30(25): e202304296, 2024 May 02.
Artículo en Inglés | MEDLINE | ID: mdl-38380537

RESUMEN

Sodium/potassium-ion batteries (NIBs and KIBs) are considered the most promising candidates for lithium-ion batteries in energy storage fields. Tin sulfide (SnS2) is regarded as an attractive negative candidate for NIBs and KIBs thanks to its superior power density, high-rate performance and natural richness. Nevertheless, the slow dynamics, the enormous volume change and the decomposition of polysulfide intermediates limit its practical application. Herein, microcubes SnS2 were prepared through sacrificial MnCO3 template-assisted and a facile solvothermal reaction strategy and their performance was investigated in Na and K-based cells. The unique hollow cubic structure and well-confined SnS2 nanosheets play an important role in Na+/K+ rapid kinetic and alleviating volume change. The effect of the carbon additives (Super P/C65) on the electrochemical properties were investigated thoroughly. The in operando and ex-situ characterization provide a piece of direct evidence to clarify the storage mechanism of such conversion-alloying type negative electrode materials.

7.
Eur Radiol ; 34(1): 715-723, 2024 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-37581653

RESUMEN

OBJECTIVES: Microwave ablation (MWA) has achieved excellent long-term efficacy in treating unifocal papillary thyroid microcarcinoma (UPTMC). The therapeutic effect of this treatment on multifocal papillary thyroid microcarcinoma (MPTMC) is unknown. Therefore, we evaluated the long-term efficacy of MWA for low-risk MPTMC and to provide evidence-based medicine for the revision of clinical guidelines. METHODS: This study included 66 MPTMC patients with a total of 158 lesions, all of whom received MWA. We collected and retrospectively analyzed the patients' follow-up data before MWA, at 1, 3, 6, and 12 months posttreatment and every 6 months thereafter until 5 years posttreatment. We evaluated the MWA complication rate, technical success rate (TSR), lesion volume reduction rate (VRR), and complete disappearance rate (CDR) during follow-up and in those patients with tumor progression and delayed surgery. RESULTS: After 60 months of follow-up, all 158 lesions disappeared in 66 patients, and the volume was reduced from 43.82 mm3 to 0.00 mm3. The TSR and VRR were both 100%. The CDRs at 1 year, 2 years, and 3 years were 57.59%, 93.67%, and 100%, respectively. The complication rate was 3.03% (2/66), and the incidence of tumor progression was 3.03% (2/66), including one new intrathyroidal lesion and one cervical lymph node metastasis (LNM). These lesions were retreated with MWA, and the lesions disappeared during the follow-up period. CONCLUSIONS: Ultrasound-guided MWA for low-risk MPTMC is safe and effective and may serve as an alternative option for patients who refuse surgery or active surveillance (AS). CLINICAL RELEVANCE STATEMENT: This study concludes that ultrasound-guided microwave ablation for low-risk multifocal papillary thyroid microcarcinoma is safe and effective and may serve as an alternative option for patients who refuse surgery or active surveillance. KEY POINTS: • Ultrasound-guided microwave ablation for low-risk multifocal papillary thyroid microcarcinoma is safe and effective. • During 5 years of follow-up, multifocal papillary thyroid microcarcinoma patients treated with microwave ablation had a favorable prognosis. • To provide evidence-based medicine for the revision of clinical guidelines.


Asunto(s)
Carcinoma Papilar , Microondas , Neoplasias de la Tiroides , Humanos , Estudios de Seguimiento , Microondas/uso terapéutico , Estudios Retrospectivos , Neoplasias de la Tiroides/diagnóstico por imagen , Neoplasias de la Tiroides/cirugía , Neoplasias de la Tiroides/patología , Resultado del Tratamiento , Ultrasonografía Intervencional
8.
Environ Res ; 251(Pt 2): 118721, 2024 Jun 15.
Artículo en Inglés | MEDLINE | ID: mdl-38490624

RESUMEN

The gradual increase in cattle farming has led to a huge production of cattle manure (CM), but the conventional treatment methods are less efficient. In this study, the treatment method of anaerobic digestion (AD) of high-solids CM by combining nanobubble water (NBW) with different gases was proposed to present a new idea for the reduction, harmlessness, and resourcefulness of CM. It was found that the performance of the digester with added NBW was better than the control. Among them, the cumulative methane yield T-Air: 227.09 mL g-1 VSadded and T-CO2: 226.12 mL g-1 VSadded increased by 17.72 % and 17.22 %, respectively, compared with the control T: 192.90 mL g-1 VSadded under thermophilic conditions. Under mesophilic conditions, M-Air: 162.39 mL g-1 VSadded increased by 9.68 % compared with control M: 148.05 mL g-1 VSadded. Microbial communities analyzed at the genus level revealed that the relative abundance of bacteria favorable to hydrolysis and acid-producing processes, such as Defluviitalea, Haloplasma, and Bacillus, increased to varying degrees. Moreover, the relative abundance of archaea favorable for methanogenesis, such as Methanoculleus, Methanobrevibacter, and Methanosarcina, also increased to varying degrees. Therefore, the addition of NBW promoted the hydrolysis of high-solids CM, enhanced the stability of the reaction, improved the methanogenic performance, and increased the RA of favorable genera, which ultimately led to a better performance of the AD of high-solids CM.


Asunto(s)
Estiércol , Metano , Estiércol/microbiología , Animales , Bovinos , Anaerobiosis , Metano/metabolismo , Metano/análisis , Agua/química , Reactores Biológicos , Bacterias/metabolismo
9.
J Am Chem Soc ; 145(42): 23000-23013, 2023 10 25.
Artículo en Inglés | MEDLINE | ID: mdl-37842926

RESUMEN

Rhodamine dyes are excellent scaffolds for developing a broad range of fluorescent probes. A key property of rhodamines is their equilibrium between a colorless lactone and fluorescent zwitterion. Tuning the lactone-zwitterion equilibrium constant (KL-Z) can optimize dye properties for specific biological applications. Here, we use known and novel organic chemistry to prepare a comprehensive collection of rhodamine dyes to elucidate the structure-activity relationships that govern KL-Z. We discovered that the auxochrome substituent strongly affects the lactone-zwitterion equilibrium, providing a roadmap for the rational design of improved rhodamine dyes. Electron-donating auxochromes, such as julolidine, work in tandem with fluorinated pendant phenyl rings to yield bright, red-shifted fluorophores for live-cell single-particle tracking (SPT) and multicolor imaging. The N-aryl auxochrome combined with fluorination yields red-shifted Förster resonance energy transfer (FRET) quencher dyes useful for creating a new semisynthetic indicator to sense cAMP using fluorescence lifetime imaging microscopy (FLIM). Together, this work expands the synthetic methods available for rhodamine synthesis, generates new reagents for advanced fluorescence imaging experiments, and describes structure-activity relationships that will guide the design of future probes.


Asunto(s)
Transferencia Resonante de Energía de Fluorescencia , Colorantes Fluorescentes , Colorantes Fluorescentes/química , Rodaminas/química , Microscopía Fluorescente/métodos , Lactonas
10.
Small ; 19(38): e2302386, 2023 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-37196415

RESUMEN

Sluggish redox kinetics and shuttle effect of polysulfides hinder the extensive application of the lithium-sulfur batteries (LSBs). Herein a functional heterostructure of boron nitride (BN) and MXene with an alternately layered structure (BN@MXene) is designed as separator interlayer. High efficiency Li+ transmission, uniform lithium deposition, strong adsorption, and efficient catalytic conversion activities of lithium polysulfides (LiPSs) realized by this heterostructure are confirmed by experiments and theoretical calculations. The alternately layered structure provides unblocked ion transmission channels and abundant active sites to accelerate the polysulfides redox kinetics with reduced energy barriers of oxidation and reduction reactions. As a result, the LSBs deliver an initial discharge capacity of up to 1273.9 mAh g-1 at 0.2 °C and a low decay of 0.058% per cycle in long-term cycling up to 700 cycles at 1 °C. This work provides an effective designing strategy to accelerate the polysulfides redox kinetics for advanced Li-S electrochemical system.

11.
Nat Methods ; 17(4): 430-436, 2020 04.
Artículo en Inglés | MEDLINE | ID: mdl-32203384

RESUMEN

To image the accessible genome at nanometer scale in situ, we developed three-dimensional assay for transposase-accessible chromatin-photoactivated localization microscopy (3D ATAC-PALM) that integrates an assay for transposase-accessible chromatin with visualization, PALM super-resolution imaging and lattice light-sheet microscopy. Multiplexed with oligopaint DNA-fluorescence in situ hybridization (FISH), RNA-FISH and protein fluorescence, 3D ATAC-PALM connected microscopy and genomic data, revealing spatially segregated accessible chromatin domains (ACDs) that enclose active chromatin and transcribed genes. Using these methods to analyze genetically perturbed cells, we demonstrated that genome architectural protein CTCF prevents excessive clustering of accessible chromatin and decompacts ACDs. These results highlight 3D ATAC-PALM as a useful tool to probe the structure and organizing mechanism of the genome.


Asunto(s)
ADN/metabolismo , Genómica/métodos , Hibridación Fluorescente in Situ/métodos , Microscopía/métodos , Pintura Cromosómica , Genoma Humano , Secuenciación de Nucleótidos de Alto Rendimiento , Humanos , Procesamiento de Imagen Asistido por Computador , Análisis de Secuencia de ADN/métodos
12.
Opt Express ; 31(24): 40658-40674, 2023 Nov 20.
Artículo en Inglés | MEDLINE | ID: mdl-38041360

RESUMEN

Metasurfaces have enabled precise electromagnetic (EM) wave manipulation with strong potential to obtain unprecedented functionalities and multifunctional behavior in flat optical devices. One promising aspect to achieve multifunction is polarization-dependent metadevices enabled by simultaneous phase control over orthogonally polarized waves. Among these, metasurfaces with geometric phase shows their natural and robust phase control ability over different circularly polarized waves. However, the phase responses under the circularly polarized incidence are locked to be opposite with each other, resulting in limited multifunctionality. In this study, we propose what we believe to be a novel transmission-type microwave metadevice constructed by linear-to-circular metasurface and spin-decoupled metasurface. By endowing independent phase adjustment capability to each unit structure in a spin-decoupled metasurface, the metadevice can reconfigure arbitrary phase wavefronts under orthogonal polarization state incidence, thereby achieving flexible multifunctionality. As a proof-of-concept, the feasibility and reliability of proposed metasurfaces were verified by simulating multifunctional directional deflection, off-axis focusing, and focused vortex beam generation. Finally, the multifunctional manipulation capability of the metadevice is successfully demonstrated by actually measuring the generation of orbital angular momentum modes. This work is expected to drive the application development of metasurface devices in wireless communication.

13.
Eur Radiol ; 33(4): 2407-2414, 2023 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-36472698

RESUMEN

OBJECTIVES: To investigate the value of contrast-enhanced ultrasound (CEUS) combined with feeding artery ablation in the microwave ablation (MWA) of large solid benign thyroid nodules (LSBTNs) with a diameter ≥ 4 cm. METHODS: We retrospectively analyzed 122 patients with LSBTN ≥ 4 cm in diameter treated with MWA. During evaluations before and after MWA, 53 patients who underwent conventional ultrasound examination were classified as the routine group, and 69 patients who underwent CEUS combined with feeding artery ablation were classified as the union group. The differences in ablation energy required per milliliter (AERPM), complication rate, regrowth rate, and volume reduction rate (VRR) were compared between the two groups. RESULTS: The AERPM of the union group was significantly less than that of the routine group (956.3 ± 38.5 J/mL vs. 1025.9 ± 121.5 J/mL, p < 0.001). The complication rate of the routine group was significantly higher than that of the union group (13.2% vs. 2.9%, p = 0.031). The regrowth rate of the routine group (22.6%, 12/53) was significantly higher than that of the union group (7.2%, 5/69) (p = 0.015). At the 1st, 3rd, 6th, 12th, 18th, and 24th month after ablation, the mean VRRs of the routine group were significantly less than those of the union group, with p values of < 0.001, < 0.001, 0.002, 0.007, 0.013, and < 0.001, respectively. CONCLUSIONS: The application of CEUS combined with feeding artery ablation in the MWA of LSBTNs is helpful to reduce the regrowth rate, improve the ablation efficiency, and reduce bleeding. KEY POINTS: • CEUS combined with feeding artery ablation in MWA of LSBTNs is helpful to reduce regrowth rate. • CEUS combined with feeding artery ablation can help improve ablation efficiency than conventional ultrasound in LSBTNs. • CEUS combined with feeding artery ablation helps reduce the incidence of bleeding during MWA.


Asunto(s)
Ablación por Catéter , Nódulo Tiroideo , Humanos , Nódulo Tiroideo/diagnóstico por imagen , Nódulo Tiroideo/cirugía , Microondas/uso terapéutico , Estudios Retrospectivos , Resultado del Tratamiento , Arterias
14.
Environ Res ; 229: 115751, 2023 07 15.
Artículo en Inglés | MEDLINE | ID: mdl-36966997

RESUMEN

Mining and smelting are the main sources of soil heavy metal pollution. Leaching and release of heavy metals in soils has been extensively studied. However, there are few researches on the release behavior of heavy metals from the Angle of mineralogy of smelting slag. This study focuses on the pollution of arsenic and chromium by traditional pyrometallurgical lead-zinc smelting slag in southwest China. Based on the mineralogy of smelting slag, the release behavior of heavy metals in smelting slag was studied. As and Cr deposit minerals were identified by MLA analysis, and the weathering degree and bioavailability of As and Cr deposit minerals were analyzed. The results showed that the weathering degree of slag was positively correlated with the bioavailability of heavy metals. The leaching experiment results showed that the higher pH was beneficial to the release of As and Cr. It was found that the chemical forms of As and Cr changed from relatively stable forms to easily released forms (As5+ to As3+ and Cr3+ to Cr6+) by characterizing the metallurgical slag during leaching. In the transformation process, the S in the pyrite as the enclosing layer is eventually oxidized to SO42-, which will accelerate the dissolution of the enclosing mineral. SO42- will occupy the adsorption site of As on the mineral surface, thus reducing the adsorption amount of As on the mineral surface. Fe is finally oxidized to Fe2O3, and the increase of Fe2O3 content in the waste residue will produce strong adsorption effect on Cr6+ and slow down the release of Cr6+. The results show that the release of As and Cr is controlled by the pyrite coating.


Asunto(s)
Metales Pesados , Contaminantes del Suelo , Zinc/análisis , Disponibilidad Biológica , Compuestos Férricos , Plomo/análisis , Metales Pesados/análisis , Minerales/análisis , Contaminantes del Suelo/análisis , Monitoreo del Ambiente
15.
Appl Opt ; 62(30): 8184-8189, 2023 Oct 20.
Artículo en Inglés | MEDLINE | ID: mdl-38038116

RESUMEN

By inserting the monolayer graphene between the balanced gain and loss layers, the graphene-incorporated quasi-parity-time (PT) symmetric structure is established. In this contribution, the introduction of graphene provides a new degree of freedom to manipulate the optical performance as well as the photonic spin Hall effect (SHE). The coherent perfect absorption (CPA)-laser mode still remains in the graphene-incorporated quasi-PT symmetric system, and the spin shift of transmitted light can be significantly enhanced (i.e., up to its upper limitation) in the vicinity of CPA-laser mode, which is 18 times larger than the value of a simple PT symmetric structure. In addition, the excitation of the CPA-laser mode and the huge spin shift of transmitted light can be achieved with the thin gain/loss layers, which will be conducive to the miniaturization of nanophotonic devices based on the photonic SHE in the future.

16.
Sensors (Basel) ; 23(11)2023 May 27.
Artículo en Inglés | MEDLINE | ID: mdl-37299855

RESUMEN

A tunable and narrow-bandwidth Q-switched ytterbium-doped fiber (YDF) laser is investigated in this paper. The non-pumped YDF acts as a saturable absorber and, together with a Sagnac loop mirror, provides a dynamic spectral-filtering grating to achieve a narrow-linewidth Q-switched output. By adjusting an etalon-based tunable fiber filter, a tunable wavelength from 1027 nm to 1033 nm is obtained. When the pump power is 1.75 W, the Q-switched laser pulses with a pulse energy of 10.45 nJ, and a repetition frequency of 11.98 kHz and spectral linewidth of 112 MHz are obtained. This work paves the way for the generation narrow-linewidth Q-switched lasers with tunable wavelengths in conventional ytterbium, erbium, and thulium fiber bands to address critical applications such as coherent detection, biomedicine, and nonlinear frequency conversion.


Asunto(s)
Rayos Láser , Iterbio , Diseño de Equipo , Luz , Erbio
17.
J Environ Manage ; 348: 119384, 2023 Dec 15.
Artículo en Inglés | MEDLINE | ID: mdl-37925982

RESUMEN

The rapid development of electronic devices, electric vehicles and mobile energy storage devices, has increasingly emphasized the shortage of lithium resources for us in lithium-ion batteries are developing rapidly. The key to the disposal of spent lithium-ion batteries is to carry out green and efficient regeneration. Herein, we propose a one-step hydrothermal process for the direct regeneration of spent LiFePO4. To reduce the Fe3+ in the spent LiFePO4, the hydroxyl group was oxidized to an aldehyde group via a decarburization reaction, with DL-malic acid utilized as a low-cost and environmentally friendly reducing agent. The effects of various different Li concentrations, hydrothermal times and hydrothermal temperatures on the performance of regenerated LiFePO4 were investigated. The results revealed optimal electrochemical performance under a Li concentration of 1.2 mol L-1, a hydrothermal time of 6 h, and a hydrothermal temperature of 100 °C. The cycling stability of LiFePO4 regenerated under these conditions considerably improved. The initial discharge specific capacity and the discharge specific capacity of the regenerated LFP after 200 cycles were 138.4 mAh g-1 and 136.6 mAh g-1. All coulomb efficiencies of the regenerated LFP were above 97.2 %, and the capacity retention rate was 98.7%. This developed method can therefore be considered a green and feasible means for regeneration of LiFePO4.


Asunto(s)
Suministros de Energía Eléctrica , Litio , Electrodos , Iones , Electricidad
18.
J Environ Manage ; 326(Pt A): 116661, 2023 Jan 15.
Artículo en Inglés | MEDLINE | ID: mdl-36372038

RESUMEN

Recycling spent lithium-ion batteries is an important means for promoting sustainability within the energy industry. In this study, the effects of residual sodium on the regeneration process and the performance of spent LiNi0.5Co0.2Mn0.3O2 were explored. An appropriate amount of residual sodium was found to improve the properties of the regenerated material, with the best cycle performance and rate performance at a residual sodium of 3 mol %. The first-cycle and 100-cycle discharge capacities were 136.4 mA h g-1 and 120 mA h g-1, respectively, with a capacity retention rate of 87.98% after 100 cycles at a rate of 1 C. The electrochemical performance of the regenerated cathode materials was improved because sodium occupied the lithium sites in the crystal structure, providing a channel for lithium deintercalation. These results indicate that the residual sodium ions should be monitored in appropriate quantities to improve the efficiency of recycling spent lithium-ion batteries.

19.
J Sci Food Agric ; 103(8): 3907-3914, 2023 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-36329649

RESUMEN

BACKGROUND: The pasting properties of rice change markedly after aging, although the mechanism for this still remains unknown. Aged and fresh rice grains were ground and the flours were fractionated by particle size, and then the pasting properties, particle size distribution and microscopic morphology of the heated flour fractions were evaluated. RESULTS: Compared to the corresponding fresh flour fractions with the same particle size, a lower peak viscosity for those aged flour fractions from 80 µm to 450 µm and a higher peak viscosity for those aged flour fractions from 20 µm to 60 µm were observed. The amounts of smaller particles disaggregated from the aged flour fractions were significantly less and the separated entities were always larger than the corresponding fresh rice fractions. CONCLUSION: Disaggregation difficulty of starch granules was the reason for the changes in the pasting properties of rice after aging. This finding is helpful for understanding rice aging mechanisms and regulating eating quality of rice flour as an ingredient. © 2022 Society of Chemical Industry.


Asunto(s)
Oryza , Almidón , Almidón/química , Oryza/química , Viscosidad , Tamaño de la Partícula , Calor , Harina/análisis
20.
Chin J Traumatol ; 26(6): 344-350, 2023 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-37925272

RESUMEN

Bosworth fracture and dislocation is relatively rare, accounting for about 1% of ankle fractures. It is characterized by the proximal fibula fracture embedded in the posterolateral distal tibia. Due to an insufficient understanding of this fracture, it is easy to cause missed diagnosis and misdiagnosis in clinical practice. Due to the insertion of the fracture, it is challenging to perform closed reduction, and improper treatment is easy to cause complications. Surgical treatment is recommended for this type of fracture. In order to improve the understanding of orthopedic surgeons about Bosworth fracture and dislocation, this paper reports the diagnosis and treatment of 2 cases of Bosworth fracture and dislocation, and reviews the literature on Bosworth fracture's mechanism, diagnosis, classification, complications, and treatment options in recent years.


Asunto(s)
Fracturas de Tobillo , Luxaciones Articulares , Humanos , Fracturas de Tobillo/diagnóstico por imagen , Fracturas de Tobillo/cirugía , Luxaciones Articulares/diagnóstico por imagen , Luxaciones Articulares/cirugía , Fijación Interna de Fracturas , Peroné , Tibia
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA