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1.
J Colloid Interface Sci ; 679(Pt A): 234-242, 2024 Sep 28.
Artículo en Inglés | MEDLINE | ID: mdl-39362148

RESUMEN

Rechargeable non-aqueous lithium-oxygen batteries (LOBs) have garnered increasing attention owing to their high theoretical energy density. However, their slow cathodic kinetics hinder efficient battery reactions. Nanoscale catalysts can effectively enhance electrocatalytic activity and atomic utilization efficiency. However, the agglomeration of nanoscale catalysts (such as cluster and single atoms) during continuous discharge/charge cycles leads to decreased electrochemical performance and poor cyclic stability. Herein, the ruthenium (Ru) atomic sites anchored on an O-doped molybdenum disulfide (O-MoS2) catalyst (designated as Ru/O-MoS2) was fabricated using a facile impregnation and calcination method. Strong Ru-O coupling between Ru atoms and the O-MoS2 substrate optimizes the localized electronic structure, resulting in improved electrochemical performance and enhanced resistance to Ostwald ripening. When employed as a cathode catalyst for LOBs, Ru/O-MoS2 catalyst exhibits a high reversible specific capacity (18700.5 (±59.8) mAh g-1), good rate capability, and enhanced long-term stability (115 cycles, 1200 h). This study encourages facile and efficient strategies for the development of effective and stable electrocatalysts for use in LOBs.

2.
Mar Pollut Bull ; 201: 116199, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38422826

RESUMEN

Understanding PAH and OCP distributions and sources in lakes is necessary for developing pollutant control policies. Here, we assessed the occurrence, risk, and sources of PAHs and OCPs in the sediment of Caohai Lake. The PAHs were predominantly high-molecular-weight compounds (mean 57.5 %), and the diagnostic ratios revealed that coal, biomass burning, and traffic were the sources of PAHs. HCHs (6.53 ± 7.22 ng g-1) and DDTs (10.86 ± 12.16 ng g-1) were the dominant OCPs and were primarily sourced from fresh exogenous inputs. RDA showed that sediment properties explained 74.12 % and 65.44 % of the variation in PAH and OCP concentrations, respectively. Incremental lifetime cancer risk (ILCR) assessment indicated that hazardous PAHs in Caohai Lake sediment posed moderate risks to children and adults (ILCR>1.0 × 10-4), while the risk from OCPs was low; however, the recent influx of HCHs and DDTs requires additional attention.


Asunto(s)
Hidrocarburos Clorados , Plaguicidas , Hidrocarburos Policíclicos Aromáticos , Contaminantes Químicos del Agua , Niño , Humanos , Lagos , Humedales , Hidrocarburos Policíclicos Aromáticos/análisis , Contaminantes Químicos del Agua/análisis , Monitoreo del Ambiente , Plaguicidas/análisis , Hidrocarburos Clorados/análisis , China , Sedimentos Geológicos
3.
J Colloid Interface Sci ; 628(Pt B): 922-930, 2022 Dec 15.
Artículo en Inglés | MEDLINE | ID: mdl-36030717

RESUMEN

Efficient nonprecious bifunctional electrocatalysts toward oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) are essential for improving the electrochemical performance of Zinc-air (Zn-air) batteries. Herein, we report a cobalt-doped Mn2(OH)3VO3 catalyst prepared by facile hydrothermal method, and the ratios of cationic redox couples of catalysts were tuned with different Co doping amounts. The as-prepared Mn1.8Co0.2(OH)3VO3 (MnCoVO-1) catalyst achieves the highest ratio of (Mn3+Mn4+)/Mn2+ and Co3+/Co2+ redox couples which serve as ORR and OER active sites respectively, and exhibits the enhanced electrocatalytic performance. Furthermore, when employed as air-cathode catalyst for rechargeable Zn-air batteries, the MnCoVO-1 catalyst reveals a high power density (278 mW cm-2), enhanced rate performance and outstanding long-term stability of over 270 h. This work demonstrates the Co-doped Mn2(OH)3VO3 with optimized electronic structure by rational doping engineering can serve as a promising bifunctional catalyst for oxygen electrocatalysis and rechargeable Zn-air batteries.

4.
Small ; 17(4): e2006183, 2021 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-33377268

RESUMEN

Development of highly active, robust electrocatalysts to accelerate the sluggish oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) is crucial and challenging for the practical application of metal-air batteries. In this effort, a novel and facile self-jet vapor-phase growth approach is developed, from which highly dispersive FeNi alloy nanoparticles (NPs) encapsulated in N-doped carbon nanotubes (NCNT) grown on a cotton pad (FeNi@NCNT-CP) can be fabricated. The as-prepared FeNi@NCNT-CP clusters exhibit superior bifunctional catalytic activity, with a high half-wave potential of 0.85 V toward ORR and a low potential of 1.59 V at 10 mA cm-2 toward OER. Specifically, owing to the synergistic effects of FeNi alloy NPs and NCNT, FeNi@NCNT-CP clusters deliver excellent stability, demonstrating a small potential gap of 0.73 V between ORR and OER after operation for 10 000 cycles. Furthermore, FeNi@NCNT-CP serves as a cost-effective, superior catalyst for the cathode of a rechargeable Zn-air battery, outperforming a catalyst mixture of expensive Pt/C and IrO2 . FeNi@NCNT-CP provides a maximum power density of 200 mW cm-2 and a cycling stability of up to 250 h. This contribution provides new prospects to prepare non-noble electrocatalysts for metal-air battery cathodes.

5.
J Chem Inf Model ; 58(8): 1587-1595, 2018 08 27.
Artículo en Inglés | MEDLINE | ID: mdl-30067339

RESUMEN

Amyloid aggregation initiates from a slow nucleation process, where the association of monomers is unfavorable in energetics. In principle, the enthalpy change for aggregation should compensate the entropy loss as new monomers attach to formed oligomers. However, the classical force fields with fixed point charges failed to yield the correct enthalpy change due to the lack of electrostatic polarization effect on amyloid aggregation. In this work, we performed molecular dynamics simulation for the full-length human islet amyloid using the polarized protein-specific charges and calculated the electrostatic interaction energy for amyloid oligomers. The results of molecular dynamics simulation show that the aggregates simulated with polarized charges have larger enthalpy change than that with fixed charges. The large enthalpy change mainly originates from the electrostatic polarization, which makes a significant contribution to the cooperative effect of aggregation and facilitates the nucleation process of amyloids.


Asunto(s)
Polipéptido Amiloide de los Islotes Pancreáticos/química , Agregado de Proteínas , Amiloide/química , Humanos , Enlace de Hidrógeno , Simulación de Dinámica Molecular , Conformación Proteica , Electricidad Estática , Termodinámica
6.
Med Sci Monit ; 24: 4832-4840, 2018 Jul 12.
Artículo en Inglés | MEDLINE | ID: mdl-30001299

RESUMEN

BACKGROUND Brachial plexus injury (BPI), a severe nervous system injury, is a leading cause of functional damages of the affected upper limb. Patients with BPI manifested with motor weakness or paralysis, sensory deficits, and pain. We established a BPI rat model to explore the in vivo effect of end-to-side screw anastomosis (ETSSA) of phrenic nerve on the recovery of limb function after BPI. MATERIAL AND METHODS After modeling, rats were treated with end-to-side anastomosis (ETSA) and ETSSA respectively. After 1 and 3 months, the behavioral changes of rats were observed using the Terzis grooming test, and the compound muscle action potential (CMAP) and muscle tension of biceps brachii were detected. The muscle weight recovery rate (MWRR) and cross-sectional area recovery rate (CARR) were calculated. Toluidine blue staining was used to observe the myelinated nerve fibers in the proximal phrenic nerve and distal musculocutaneous nerve of suture. The ratio of regenerated nerve traversing rate (NTR) was counted and motor endplate area of biceps brachii was measured. RESULTS The rats treated with ETSA and ETSSA exhibited elevated grading of Terzis grooming test with time. Although both the ETSSA and ETSA can reduce the MWRR, CARR and motor endplate area in BPI rats, ETSSA showed a better influence on the latency delayed rate (LDR) and amplitude recovery rate (ARR) of CMAP, muscular tension recovery rate (MTRR), MWRR, number of regenerated myelinated nerve fibers, NTR, and motor endplate area in BPI rats. CONCLUSIONS Our study provided evidence that ETSSA can restore the limb function recovery to a greater extent, and accelerate the regeneration of nerve fibers in rats with BPI; the effect of ETSSA was better than that of ETSA.


Asunto(s)
Anastomosis Quirúrgica/métodos , Plexo Braquial/cirugía , Nervio Frénico/cirugía , Animales , Tornillos Óseos , Masculino , Neuronas Motoras , Músculo Esquelético/inervación , Regeneración Nerviosa/fisiología , Transferencia de Nervios/métodos , Procedimientos Neuroquirúrgicos , Ratas , Ratas Sprague-Dawley
7.
PLoS One ; 13(5): e0197392, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-29768506

RESUMEN

The protein kinase (PK, kinome) family is one of the largest families in plants and regulates almost all aspects of plant processes, including plant development and stress responses. Despite their important functions, comprehensive functional classification, evolutionary analysis and expression patterns of the cotton PK gene family has yet to be performed on PK genes. In this study, we identified the cotton kinomes in the Gossypium raimondii, Gossypium arboretum, Gossypium hirsutum and Gossypium barbadense genomes and classified them into 7 groups and 122-24 subfamilies using software HMMER v3.0 scanning and neighbor-joining (NJ) phylogenetic analysis. Some conserved exon-intron structures were identified not only in cotton species but also in primitive plants, ferns and moss, suggesting the significant function and ancient origination of these PK genes. Collinearity analysis revealed that 16.6 million years ago (Mya) cotton-specific whole genome duplication (WGD) events may have played a partial role in the expansion of the cotton kinomes, whereas tandem duplication (TD) events mainly contributed to the expansion of the cotton RLK group. Synteny analysis revealed that tetraploidization of G. hirsutum and G. barbadense contributed to the expansion of G. hirsutum and G. barbadense PKs. Global expression analysis of cotton PKs revealed stress-specific and fiber development-related expression patterns, suggesting that many cotton PKs might be involved in the regulation of the stress response and fiber development processes. This study provides foundational information for further studies on the evolution and molecular function of cotton PKs.


Asunto(s)
Genoma de Planta/genética , Gossypium/genética , Cromosomas de las Plantas/genética , Evolución Molecular , Duplicación de Gen/genética , Perfilación de la Expresión Génica , Regulación de la Expresión Génica de las Plantas/genética , Familia de Multigenes , Filogenia , Sintenía
8.
J Med Case Rep ; 12(1): 74, 2018 Mar 21.
Artículo en Inglés | MEDLINE | ID: mdl-29558996

RESUMEN

BACKGROUND: Skeletal and soft tissue damage are often associated with unilateral facet dislocations, which undoubtedly lead to instability of the spine and further increase difficulties in cervical reduction. This type of irreducible facet dislocation is usually accompanied with potential catastrophic consequences including neurological deficit and severe disability. Therefore, a consistent and evidence-based treatment plan is imperative. CASE PRESENTATION: The literature regarding the management of traumatic unilateral locked cervical facet dislocations was reviewed. Two patient cases (a 30-year-old Asian man and a 25-year-old Asian woman) who suffered irreducible cervical facet dislocations were presented. These two patients received surgical treatments including posterior reduction by poking facet joints, adjacent spinous process fixation by wire rope banding, anterior plate fixation, and intervertebral fusion after the failure of skull traction and closed reduction. At the postoperative 24-month follow-up, intervertebral fusion was achieved and our patients' neurological status improved based on the American Spinal Injury Association scale, compared with their preoperative status. CONCLUSIONS: Unilateral facet joint dislocations of subaxial cervical spine are difficult to reduce when complicated with posterior facet fractures or ligamentous injury. Magnetic resonance imaging can be beneficial for identifying ventral and dorsal compressive lesions, as well as ligamentous or capsule rupture. The combination of posterior reduction and anterior fixation with fusion has advantages in terms of clinical safety, ease of operation, and less iatrogenic damage.


Asunto(s)
Vértebras Cervicales/lesiones , Descompresión Quirúrgica , Luxaciones Articulares/cirugía , Paraplejía/cirugía , Compresión de la Médula Espinal/cirugía , Fusión Vertebral , Traumatismos Vertebrales/cirugía , Articulación Cigapofisaria/diagnóstico por imagen , Adulto , Hilos Ortopédicos , Vértebras Cervicales/diagnóstico por imagen , Femenino , Estudios de Seguimiento , Humanos , Disco Intervertebral/lesiones , Luxaciones Articulares/diagnóstico por imagen , Luxaciones Articulares/fisiopatología , Imagen por Resonancia Magnética , Masculino , Paraplejía/etiología , Paraplejía/fisiopatología , Recuperación de la Función/fisiología , Compresión de la Médula Espinal/diagnóstico por imagen , Compresión de la Médula Espinal/fisiopatología , Fusión Vertebral/métodos , Traumatismos Vertebrales/diagnóstico por imagen , Traumatismos Vertebrales/fisiopatología , Resultado del Tratamiento , Articulación Cigapofisaria/fisiopatología , Articulación Cigapofisaria/cirugía
9.
ChemSusChem ; 11(3): 574-579, 2018 02 09.
Artículo en Inglés | MEDLINE | ID: mdl-29235727

RESUMEN

Carbon is usually used as cathode material for Li-O2 batteries. However, the discharge product, such as Li2 O2 and LiO2 , could react with carbon to form an insulating lithium carbonate layer, resulting in cathode passivation and capacity fading. To solve this problem, the development of non-carbon cathodes is highly desirable. Herein, we successfully synthesized MnCo2 O4 (MCO) nanoparticles anchored on porous MoO2 nanosheets that are grown on Ni foam (current collector) (MCO/MoO2 @Ni), acting as a carbon- and binder-free cathode for Li-O2 batteries, in an attempt to improve the electrical conductivity, electrocatalytic activity, and durability. This MCO/MoO2 @Ni electrode delivers excellent cyclability (more than 400 cycles) and rate performance (voltage gap of 0.75 V at 5000 mA g-1 ). Notably, the battery with this electrode exhibits a high energy efficiency (higher than 85 %). The advanced electrochemical performance of MCO/MoO2 @Ni can be attributed to its high electrical conductivity, excellent stability, and outstanding electrocatalytic activity. This work offers a new strategy to fabricate high-performance Li-O2 batteries with non-carbon cathode materials.


Asunto(s)
Carbono/química , Cobalto/química , Suministros de Energía Eléctrica , Electrodos , Litio/química , Manganeso/química , Molibdeno/química , Nanoestructuras , Níquel/química , Óxidos/química , Oxígeno/química , Catálisis , Conductividad Eléctrica , Técnicas Electroquímicas , Porosidad
10.
Acta cir. bras ; 32(12): 1064-1074, Dec. 2017. tab, graf
Artículo en Inglés | LILACS | ID: biblio-886190

RESUMEN

Abstract Purpose: To investigate tibial tunnel widening and knee instability after ACL reconstruction with hamstring autograft or irradiated soft tissue allograft. Methods: Eight-two patients were divided into two groups: autograft group and allograft group. Radiographic and clinical evaluations were performed. Results: Seventy patients were followed up with median of 36.3 months (range 36-38 months). Tibial tunnel widening was at or greater than 30% for nine patients in the autograft group and 15 patients in the allograft group (P = 0.0417). The average percentage of tibial tunnel widening was 26.7 ± 4.0 % and 29.7 ± 5.3 % in autograft and allograft groups, respectively (P = 0.0090). Knee range of motion was not affected by the reconstruction operation or different grafts. Thigh atrophy improved significantly within 24 months after ACL reconstructions in both groups. ACL reconstruction with the allograft leaded to less knee stability than that with the autograft from one year after operation (P = 0.0023). There was no significant difference between two groups with respect to Lysholm score (P = 0.1925) and Tegner score (P =0 .0918) at the final follow-up. Conclusion: The allograft group reported significantly more tibial tunnel widening and knee instability compared with the autograft group.


Asunto(s)
Humanos , Masculino , Femenino , Adolescente , Adulto , Adulto Joven , Tibia/cirugía , Reconstrucción del Ligamento Cruzado Anterior/métodos , Lesiones del Ligamento Cruzado Anterior/cirugía , Inestabilidad de la Articulación/cirugía , Osteotomía/métodos , Periodo Posoperatorio , Muslo/patología , Estudios Prospectivos , Estudios de Seguimiento , Resultado del Tratamiento , Periodo Preoperatorio , Reconstrucción del Ligamento Cruzado Anterior/efectos adversos , Reconstrucción del Ligamento Cruzado Anterior/rehabilitación , Tempo Operativo , Aloinjertos/trasplante , Autoinjertos/trasplante , Tendones Isquiotibiales/trasplante
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