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1.
Chem Commun (Camb) ; 60(22): 3067-3070, 2024 Mar 12.
Artigo em Inglês | MEDLINE | ID: mdl-38386357

RESUMO

MnO2-Mn3O4 heterostructure materials are applied in aqueous magnesium ion energy storage for the first time. The heterostructure yields an exceptionally high pseudocapacitance contribution, resulting in a specific capacitance of 313.5 F g-1 at 1 A g-1, which contrasts with that of MnO2 (108.8 F g-1) and Mn3O4 (123.5 F g-1). Additionally, it shows potential for practical applications as a cathode for magnesium ion hybrid supercapacitors (MHS).

2.
Dalton Trans ; 53(4): 1640-1647, 2024 Jan 23.
Artigo em Inglês | MEDLINE | ID: mdl-38167672

RESUMO

Manganese oxides are commonly employed as a cathode for magnesium ion storage in aqueous magnesium ion hybrid supercapacitors (MHS). However, sluggish reaction kinetics still hinders their practical application. Herein, we designed K-birnessite-MnO2 and electrostatically spun mulberry-like carbon composites (K-MnO2/HMCs) via an in situ growth technique. Benefiting from the 3D conductive carbon network substrate, the in situ fabricated K-MnO2 exhibits more active sites and provides more interfacial contact area between the electrode material and the electrolyte. This improvement enhances its conductivity, facilitating the rapid transfer of electrons, diffusion of ions, and redox reactions. As a result, K-MnO2/HMC-based MHS achieves a specific capacity of 168 mA h g-1 at 0.5 A g-1, simultaneously exhibiting a superior energy density of 111.1 W h kg-1 at a power density of 505 W kg-1. Furthermore, it demonstrates excellent high rate performance and a long cycling life for aqueous magnesium ion storage, offering new insights for MHS applications.

3.
ACS Nano ; 17(21): 20804-20824, 2023 Nov 14.
Artigo em Inglês | MEDLINE | ID: mdl-37922197

RESUMO

The splitting of water through electrocatalysis offers a sustainable method for the production of hydrogen. In alkaline electrolytes, the lack of protons forces water dissociation to occur before the hydrogen evolution reaction (HER). While pure Pt is the gold standard electrocatalyst in acidic electrolytes, since the 5d orbital in Pt is nearly fully occupied, when it overlaps with the molecular orbital of water, it generates a Pauli repulsion. As a result, the formation of a Pt-H* bond in an alkaline environment is difficult, which slows the HER and negates the benefits of using a pure Pt catalyst. To overcome this limitation, Pt can be alloyed with transition metals, such as Fe, Co, and Ni. This approach has the potential not only to enhance the performance but also to increase the Pt dispersion and decrease its usage, thus overall improving the catalyst's cost-effectiveness. The excellent water adsorption and dissociation ability of transition metals contributes to the generation of a proton-rich local environment near the Pt-based alloy that promotes HER. Significant progress has been achieved in comprehending the alkaline HER mechanism through the manipulation of the structure and composition of electrocatalysts based on the Pt alloy. The objective of this review is to analyze and condense the latest developments in the production of Pt-based alloy electrocatalysts for alkaline HER. It focuses on the modified performance of Pt-based alloys and clarifies the design principles and catalytic mechanism of the catalysts from both an experimental and theoretical perspective. This review also highlights some of the difficulties encountered during the HER and the opportunities for increasing the HER performance. Finally, guidance for the development of more efficient Pt-based alloy electrocatalysts is provided.

4.
Front Biosci (Landmark Ed) ; 28(12): 365, 2023 12 29.
Artigo em Inglês | MEDLINE | ID: mdl-38179756

RESUMO

BACKGROUND: Diabetic liver disease is one of the main complications that leads to the aggravation of diabetes, but it has not received sufficient attention. This study aimed to provide a better understanding of the altered molecular networks in in diabetic rats with liver damage after stem cell therapy. To a certain extent, our research would be instructive, since almost no studies of this kind have been performed on patients with diabetic liver disease after stem cell therapy. METHODS: Streptozotocin-induced diabetic rats were treated with adipose-derived stem cells. RNA-Seq analysis was performed on the liver tissues of these animals, and key pathway factors were further identified and validated. RESULTS: RNA-Seq analysis revealed numerous affected signaling pathways and functional categories. The results showed that the network of dual specificity phosphatase 1 (DUSP1), an oxidative stress-related gene, was prominently activated in the liver after stem cell therapy, and the enrichment of genes associated with liver damage, steatosis and fibrosis was also detected. The extracellular regulated protein kinase (ERK)/signal transducer and activator of transcription 3 (STAT3) signaling pathway may be involved in this process by regulating the nucleotide-binding and oligomerization domain-like receptor family pyrin domain-containing 3 (NLRP3) inflammasome. CONCLUSIONS: These data provide novel insights into liver biology, suggest common alterations in the molecular networks during diabetic liver damage, and show the advantages of stem cell therapy, indicating its further application potential for early treatment of diabetic liver damage and delaying the progression of liver fibrosis in the later stage.


Assuntos
Complicações do Diabetes , Diabetes Mellitus Experimental , Humanos , Ratos , Animais , Diabetes Mellitus Experimental/complicações , Diabetes Mellitus Experimental/genética , Diabetes Mellitus Experimental/metabolismo , Transcriptoma , Transdução de Sinais/genética , Proteína 3 que Contém Domínio de Pirina da Família NLR/metabolismo , Inflamassomos/metabolismo , Células-Tronco/metabolismo
5.
J Oleo Sci ; 69(6): 627-634, 2020 Jun 04.
Artigo em Inglês | MEDLINE | ID: mdl-32404552

RESUMO

Present study has successfully synthesized melamine-based covalent organic polymers (MCOPs) and applied it as lipase carrier for recyclable esters hydrolysis and transesterification. The synthesized MCOPs are composed of dense nanosheet structures having a thickness of 3.5 nm. Three immobilization methods namely physical adsorption, cross-linking and carrier activation were employed to prepare the MCOPs-immobilized CRL. Cross-linked MCOPs-immobilized CRL (41.30 mg protein/g MCOPs) and carrier activated MCOPs-immobilized CRL (33.20 mg protein/g MCOPs) had higher enzyme loading as compared to physical absorb MCOPs-immobilized CRL (29.30 mg protein/g MCOPs). Nevertheless, physical absorb MCOPs-immobilized CRL demonstrated the highest esters hydrolysis (49.85 U) and transesterification (1.04 U) activities. Despite having the highest enzymatic activity, physical absorb MCOPs-immobilized CRL were not able to maintain its catalytic stability with more than 30% decreased in enzymatic activity during consecutive hydrolysis and transesterification activities. Meanwhile, cross-linked MCOPs-immobilized CRL demonstrated highest catalytic stability with highest enzymatic activities at the end of consecutive reactions. All the MCOPs-immobilized CRL can be easily recovered and reused through centrifugation with more than 85% of recovery rate.


Assuntos
Polímeros/química , Polímeros/síntese química , Triazinas/química , Triazinas/síntese química , Catálise , Enzimas Imobilizadas , Esterificação , Ésteres , Hidrólise , Lipase
6.
J Colloid Interface Sci ; 565: 513-522, 2020 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-31982718

RESUMO

Cobalt phosphides, as low cost and abundant non-noble materials for hydrogen evolution reaction (HER), are always constrained by their inferior charge transfer and sluggish intrinsic electrocatalytic kinetics. In this work, carbon-incorporated Co/Co2P microspheres (Co/Co2P@C) as a novel Mott-Schottky catalyst were synthesized successfully via carbonization and gradual phosphorization of Co based metal-organic frameworks. The unique merits, including Mott-Schottky effect at the interface formed between metal Co and semiconductor Co2P, the incorporated carbon-layer on the surface and the spherical structure endow Co/Co2P@C with favorable electrical conductivity, preferable kinetics and long-term stability when it was evaluated as electrocatalyst for HER in wide-pH range. As a result, the Co/Co2P@C with the optimized phosphorization degree delivers a benchmark current density of 10 mA cm-2 at the low overpotential of 192 and 158 mV in acidic and alkaline electrolytes, respectively, with a remarkable stability (CV cycling for 3000 cycles and continuous electrolysis at the overpotential of 200 mV for 48 h). Therefore, the as-designed Co/Co2P@C should be one of the most promising catalysts for HER application.

7.
Beilstein J Nanotechnol ; 8: 649-656, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28462066

RESUMO

Metall oxides have been proven to be potential candidates for the anode material of lithium-ion batteries (LIBs) because they offer high theoretical capacities, and are environmentally friendly and widely available. However, the low electronic conductivity and severe irreversible lithium storage have hindered a practical application. Herein, we employed ethanolamine as precursor to prepare Fe2O3/COOH-MWCNT composites through a simple hydrothermal synthesis. When these composites were used as electrode material in lithium-ion batteries, a reversible capacity of 711.2 mAh·g-1 at a current density of 500 mA·g-1 after 400 cycles was obtained. The result indicated that Fe2O3/COOH-MWCNT composite is a potential anode material for lithium-ion batteries.

8.
ACS Nano ; 11(4): 3841-3850, 2017 04 25.
Artigo em Inglês | MEDLINE | ID: mdl-28375599

RESUMO

We demonstrate fabrication of a two-dimensional Hf-containing MXene, Hf3C2Tz, by selective etching of a layered parent Hf3[Al(Si)]4C6 compound. A substitutional solution of Si on Al sites effectively weakened the interfacial adhesion between Hf-C and Al(Si)-C sublayers within the unit cell of the parent compound, facilitating the subsequent selective etching. The underlying mechanism of the Si-alloying-facilitated etching process is thoroughly studied by first-principles density functional calculations. The result showed that more valence electrons of Si than Al weaken the adhesive energy of the etching interface. The MXenes were determined to be flexible and conductive. Moreover, this 2D Hf-containing MXene material showed reversible volumetric capacities of 1567 and 504 mAh cm-3 for lithium and sodium ions batteries, respectively, at a current density of 200 mAg-1 after 200 cycles. Thus, Hf3C2Tz MXenes with a 2D structure are candidate anode materials for metal-ion intercalation, especially for applications where size matters.

9.
Org Lett ; 18(16): 4088-91, 2016 08 19.
Artigo em Inglês | MEDLINE | ID: mdl-27499149

RESUMO

A mild, transition metal-free, diborane-mediated deoxygenation of nitro groups was discovered that in situ generates nitrosoarene reactive intermediates. This new reactivity mode of B2pin2 was leveraged to construct indoles from o-nitrostyrenes through a reductive-cyclization reaction that exhibits a Hammett ρ-value of +0.97 relative to σpara values. Our new deoxygenation reaction is efficient, practical, and scaleable, enabling access to a broad range of indoles.

10.
Clin Chim Acta ; 452: 124-8, 2016 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-26569346

RESUMO

BACKGROUND: Caspase-cleaved Cytokeratin-18 (CCCK-18) is released during apoptosis. Serum CCCK-18 concentrations are associated with prognosis of some critical illness. We investigated the potential relationships between serum CCCK-18 concentrations and disease severity and long-term clinical outcomes after intracerebral hemorrhage. METHODS: Serum CCCK-18 concentrations were determined in a total of 102 patients and 102 controls. Multivariate models were used to predict high concentration of CCCK-18 and 6-month clinical outcomes. The predictive values were evaluated based on areas under receiver operating curve. RESULTS: Compared with controls, serum CCCK-18 concentrations were increased in patients (245.8±108.3U/l vs. 23.6±18.1U/l, P<0.001). National Institute of Health Stroke Scale scores [odds ratio (OR), 1.164; 95% confidence interval (CI), 1.027-1.320; P=0.003] and hematoma volumes (OR, 1.079; 95% CI, 1.018-1.205; P=0.008) were independent predictors of high concentration of CCCK-18. CCCK-18 was identified as an independent predictor of 6-month mortality (OR, 1.019; 95% CI, 1.010-1.038; P=0.013) and 6-month unfavorable outcome (OR, 1.017; 95% CI, 1.008-1.029; P=0.032) and possessed high predictive values. CONCLUSION: Increased serum CCCK-18 concentrations are associated with disease severity and clinical outcomes, suggesting that CCCK represent a novel prognostic predictive biomarker after intracerebral hemorrhage.


Assuntos
Caspases/metabolismo , Hemorragia Cerebral/sangue , Hemorragia Cerebral/diagnóstico , Queratina-18/sangue , Queratina-18/metabolismo , Doença Aguda , Idoso , Análise Química do Sangue , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Prognóstico
11.
Clin Chim Acta ; 425: 85-9, 2013 Oct 21.
Artigo em Inglês | MEDLINE | ID: mdl-23916712

RESUMO

BACKGROUND: Visfatin, a proinflammatory mediator, has been associated with poor clinical outcomes after acute brain injury. The present study is designed to investigate the potential association between plasma visfatin levels and the risk of hematoma growth (HG) and early neurologic deterioration (END) after intracerebral hemorrhage. METHODS: There were 85 patients as cases who presented with first-time hemorrhagic stroke that were assessed within 6h after the incident. The control group consisted of 85 healthy volunteers. HG was defined as hematoma enlargement >33% at 24h. END was defined as an increase of ≥ 4 points in National Institute of Health Stroke Scale score at 24h from symptoms onset. Plasma visfatin levels were determined using enzyme immunoassay. RESULTS: Plasma visfatin levels were significantly higher in patients compared to controls. Plasma visfatin level emerged as an independent predictor of HG [odds ratio (OR), 1.154; 95% confidence interval (CI), 1.046-3.108; P=0.009] and END (OR, 1.195; 95% CI, 1.073-3.516; P=0.005). For predicting HG, area under curve (AUC) of plasma visfatin level (0.814; 95% CI: 0.715-0.890) was similar to that of hematoma volume (0.839; 95% CI, 0.743-0.909) (P=0.703). For predicting END, AUC of plasma visfatin level (0.828; 95% CI: 0.730-0.901) was similar to that of hematoma volume (0.863; 95% CI, 0.771-0.928) (P=0.605). Visfatin did not improve AUC of hematoma volume for predicting HG and END (both P>0.05). CONCLUSION: Plasma visfatin level represents a novel biomarker for predicting HG and END.


Assuntos
Hemorragia dos Gânglios da Base/sangue , Biomarcadores/sangue , Disfunção Cognitiva/sangue , Citocinas/sangue , Hematoma/sangue , Nicotinamida Fosforribosiltransferase/sangue , Idoso , Área Sob a Curva , Hemorragia dos Gânglios da Base/diagnóstico , Hemorragia dos Gânglios da Base/fisiopatologia , Estudos de Casos e Controles , Disfunção Cognitiva/diagnóstico , Disfunção Cognitiva/fisiopatologia , Citocinas/genética , Feminino , Expressão Gênica , Hematoma/diagnóstico , Hematoma/fisiopatologia , Hospitalização , Humanos , Masculino , Pessoa de Meia-Idade , Nicotinamida Fosforribosiltransferase/genética , Prognóstico , Curva ROC , Fatores de Tempo
13.
Zhonghua Er Bi Yan Hou Ke Za Zhi ; 37(5): 370-2, 2002 Oct.
Artigo em Chinês | MEDLINE | ID: mdl-12772460

RESUMO

OBJECTIVE: To evaluate the effect of one stage reconstruction for anterior skull base defect by pedicled frontal muscle compound flap after craniofacial combined approach operation. METHODS: Twelve patients with frontal skull base tumor and fracture (rudimentary cancer 5, malignant melanoma 1, neurogliocytoma 1, ethmoid sinus rhabdomyosarcoma 1, malignant papilloma 1, osteofibroma 2, underwent surgery 1) were included. The compound flap with pedicled frontal muscle galea aponeuroses pericranium was adopted which brought single blood vessel or double, and splinter skull bone. The compound flaps covered 8 cm -12 cm x 10 cm -15 cm. RESULTS: All 12 patients were successfully treated with no complication during follow-up from 1 to 48 months. CONCLUSION: The compound flaps with pedicled frontal muscle galea aponeuroses pericranium, had ample blood supply and thin pliable and strong tissue which was a good reconstruction material for frontal skull base defect.


Assuntos
Neoplasias da Base do Crânio/cirurgia , Base do Crânio/cirurgia , Retalhos Cirúrgicos , Adolescente , Adulto , Idoso , Criança , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Procedimentos de Cirurgia Plástica/métodos
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