Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 11 de 11
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Small ; 20(7): e2306757, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-37803928

RESUMO

Achieving highly performant photoanodes for oxygen evolution is key to developing photoelectrochemical devices for solar water splitting. In this work, BiVO4 photoanodes are enhanced with a series of core-shell structured bimetallic nickel-cobalt phosphides (MPs), and key insights into the role of co-catalysts are provided. The best BiVO4 /Ni1.5 Co0.5 P and BiVO4 /Ni0.5 Co1.5 P photoanodes achieve a 3.5-fold increase in photocurrent compared with bare BiVO4 . It is discovered that this enhanced performance arises from a synergy between work function, catalytic activity, and capacitive ability of the MPs. Distribution of relaxation times analysis reveals that the contact between the MPs, BiVO4 , and the electrolyte gives rise to three routes for hole injection into the electrolyte, all of which are significantly improved by the presence of a second metal cation in the co-catalyst. Kinetic studies demonstrate that the significantly improved interfacial charge injection is due to a lower charge-transfer resistance, enhanced oxygen-evolution reaction kinetics, and larger surface hole concentrations, providing deeper insights into the carrier dynamics in these photoanode/co-catalyst systems for their rational design.

2.
Small ; 20(6): e2305902, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-37775329

RESUMO

Rechargeable aqueous zinc-ion batteries are regarded as promising energy storage devices due to their attractive economic benefits and extraordinary electrochemical performance. However, the sluggish Zn2+ mass transfer behavior and water-induced parasitic reactions that occurred on the anode-electrode interface inevitably restrain their applications. Herein, inspired by the selective permeability and superior stability of plasma membrane, a thin UiO-66 metal-organic framework layer with smart aperture size is ex-situ decorated onto the Zn anode. Experimental characterizations in conjunction with theoretical calculations demonstrate that this bio-inspired layer promotes the de-solvation process of hydrated Zn2+ and reduces the effective contact between the anode and H2 O molecules, thereby boosting Zn2+ deposition kinetics and restraining interfacial parasitic reactions. Hence, the Zn||Zn cells could sustain a long lifespan of 1680 h and the Zn||Cu cells yielded a stable coulombic efficiency of over 99.3% throughout 600 cycles under the assistance of the bio-inspired layer. Moreover, pairing with δ-MnO2 cathode, the full cells also demonstrate prominent cycling stability and rate performance. From the bio-inspired design philosophy, this work provides a novel insight into the development of aqueous batteries.

3.
Chem Mater ; 35(20): 8607-8620, 2023 Oct 24.
Artigo em Inglês | MEDLINE | ID: mdl-37901142

RESUMO

Lead-free halide perovskite derivative Cs3Bi2Br9 has recently been found to possess optoelectronic properties suitable for photocatalytic CO2 reduction reactions to CO. However, further work needs to be performed to boost charge separation for improving the overall efficiency of the photocatalyst. This report demonstrates the synthesis of a hybrid inorganic/organic heterojunction between Cs3Bi2Br9 and g-C3N4 at different ratios, achieved by growing Cs3Bi2Br9 crystals on the surface of g-C3N4 using a straightforward antisolvent crystallization method. The synthesized powders showed enhanced gas-phase photocatalytic CO2 reduction in the absence of hole scavengers of 14.22 (±1.24) µmol CO g-1 h-1 with 40 wt % Cs3Bi2Br9 compared with 1.89 (±0.72) and 5.58 (±0.14) µmol CO g-1 h-1 for pure g-C3N4 and Cs3Bi2Br9, respectively. Photoelectrochemical measurements also showed enhanced photocurrent in the 40 wt % Cs3Bi2Br9 composite, demonstrating enhanced charge separation. In addition, stability tests demonstrated structural stability upon the formation of a heterojunction, even after 15 h of illumination. Band structure alignment and selective metal deposition studies indicated the formation of a direct Z-scheme heterojunction between the two semiconductors, which boosted charge separation. These findings support the potential of hybrid organic/inorganic g-C3N4/Cs3Bi2Br9 Z-scheme photocatalyst for enhanced CO2 photocatalytic activity and improved stability.

4.
ACS Appl Energy Mater ; 6(20): 10193-10204, 2023 Oct 23.
Artigo em Inglês | MEDLINE | ID: mdl-37886225

RESUMO

CO2 photocatalytic conversion into value-added fuels through solar energy is a promising way of storing renewable energy while simultaneously reducing the concentration of CO2 in the atmosphere. Lead-based halide perovskites have recently shown great potential in various applications such as solar cells, optoelectronics, and photocatalysis. Even though they show high performance, the high toxicity of Pb2+ along with poor stability under ambient conditions restrains the application of these materials in photocatalysis. In this respect, we developed an in situ assembly strategy to fabricate the lead-free double perovskite Cs2AgBiBr6 on a 2D bismuthene nanosheet prepared by a ligand-assisted reprecipitation method for a liquid-phase CO2 photocatalytic reduction reaction. The composite improved the production and selectivity of the eight-electron CH4 pathway compared with the two-electron CO pathway, storing more of the light energy harvested by the photocatalyst. The Cs2AgBiBr6/bismuthene composite shows a photocatalytic activity of 1.49(±0.16) µmol g-1 h-1 CH4, 0.67(±0.14) µmol g-1 h-1 CO, and 0.75(±0.20) µmol g-1 h-1 H2, with a CH4 selectivity of 81(±1)% on an electron basis with 1 sun. The improved performance is attributed to the enhanced charge separation and suppressed electron-hole recombination due to good interfacial contact between the perovskite and bismuthene promoted by the synthesis method.

5.
J Phys Chem Lett ; 14(41): 9150-9158, 2023 Oct 19.
Artigo em Inglês | MEDLINE | ID: mdl-37796231

RESUMO

Aqueous zinc-ion batteries are considered promising energy storage devices due to their superior electrochemical performance. Nevertheless, the uncontrolled dendrites and parasitic side reactions adversely affect the stability and durability of the Zn anode. To cope with these issues, inspired by the chelation behavior between metal ions and amino acids in the biological system, glutamic acid and aspartic acid are selected as electrolyte additives to stabilize the Zn anode. Experimental characterizations in conjunction with theoretical calculation results indicate that these additives can simultaneously modify the solvation structure of hydrated Zn2+ and preferentially adsorb onto the Zn anode, thereby restricting the occurrence of interfacial side reactions and enhancing the performance of the Zn anode. Benefiting from these synergistic effects, the as-assembled Zn-based batteries containing additive electrolytes achieved admirable electrochemical performance. From the viewpoint of electrolyte regulation, this work provides a bright direction toward the development of aqueous batteries.

6.
Adv Mater ; 35(45): e2304350, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37667871

RESUMO

The application of halide perovskites in the photoelectrochemical generation of solar fuels and feedstocks is hindered by the instability of perovskites in aqueous electrolytes and the use of expensive electrode and catalyst materials, particularly in photoanodes driving kinetically slow water oxidation. Here, solely earth-abundant materials are incorporated to fabricate a CsPbBr3 -based photoanode that reaches a low onset potential of +0.4 VRHE and 8 mA cm-2 photocurrent density at +1.23 VRHE for water oxidation, close to the radiative efficiency limit of CsPbBr3 . This photoanode retains 100% of its stabilized photocurrent density for more than 100 h of operation by replacing once the inexpensive graphite sheet upon signs of deterioration. The improved performance is due to an efficiently electrodeposited NiFeOOH catalyst on a protective self-adhesive graphite sheet, and enhanced charge transfer achieved by phase engineering of CsPbBr3 . Devices with >1 cm2 area, and low-temperature processing demonstrate the potential for low capital cost, stable, and scalable perovskite photoanodes.

7.
Molecules ; 28(16)2023 Aug 18.
Artigo em Inglês | MEDLINE | ID: mdl-37630380

RESUMO

A new skincare application scenario for dark tea, a unique and post-fermented tea popular in the health food industry, was developed in this paper. The effects of dark tea polysaccharide (DTP) on stress-induced skin problems and its mechanism of action were investigated by modeling cortisone-induced stress injury in human HaCaT keratinocytes and SZ95 sebaceous gland cells. The results showed a reduced cortisol conversion induced by cortisone under the action of DTP with a concentration of 200 µg/mL, probably by inhibiting the expression of the HSD11B1 enzyme. DTP was also able to suppress the cortisone-induced elevation of lipid levels in SZ95 sebocytes at this concentration. In addition, the composition and structure of DTP were verified by ultrafiltration, ultraviolet-visible spectrophotometry (UV-VIS), high-performance anion-exchange chromatography with pulsed amperometric detection (HPAEC-PAD) and infrared spectroscopy. In brief, DTP has a unique and significant stress-relieving effect, which provides new ideas for the development of new ingredients for the skin care industry.


Assuntos
Cortisona , Humanos , Células Epiteliais , Queratinócitos , Polissacarídeos/farmacologia , Chá
8.
Curr Neurovasc Res ; 20(1): 23-34, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36537606

RESUMO

OBJECTIVE: Thrombectomy greatly improves the clinical prognosis of patients with acute ischemic stroke (AIS). The aim of this study is to develop a nomogram model that can predict the prognosis of patients with acute ischemic stroke undergoing thrombectomy. METHODS: We retrospectively collected information of patients with acute ischemic stroke who were admitted to the stroke Green Channel of the First Affiliated Hospital of Soochow University from September 2018 to May 2022. The main outcome was defined as a three-month unfavorable outcome (modified Rankin Scale 3-6). Based on the results of multivariate regression analysis, a nomogram was established. We tested the accuracy and discrimination of our nomogram by calculating the consistency index (C-index) and plotting the calibration curve. RESULTS: National Institutes of Health Stroke Scale (NIHSS) score (OR, 1.418; 95% CI, 1.177-1.707; P<0.001), low density lipoprotein cholesterol (LDL-C) (OR, 2.705; 95% CI, 1.203-6.080; P = 0.016), Alberta Stroke Program Early Computed Tomography Score (ASPECTS) (OR, 0.633; 95% CI, 0.421-0.952; P = 0.028), infarct core volume (OR, 1.115; 95% CI, 1.043-1.192; P = 0.001) and ischemic penumbra volume (OR, 1.028; 95% CI, 1.006-1.050; P = 0.012) were independent risk factors for poor clinical prognosis of AIS patients treated with thrombectomy. The C-index of our nomogram was 0.967 and the calibration plot revealed a generally fit in predicting three-month unfavorable outcomes. Based on this nomogram, we stratified the risk of thrombectomy population. We found that low-risk population is less than or equal to 65 points, and patients of more than 65 points tend to have a poor clinical prognosis. CONCLUSION: The nomogram, composed of NIHSS, LDL-C, ASPECTS, infarct core volume and ischemic penumbra volume, may predict the clinical prognosis of cerebral infarction patients treated with thrombectomy.


Assuntos
Isquemia Encefálica , AVC Isquêmico , Acidente Vascular Cerebral , Humanos , Nomogramas , AVC Isquêmico/diagnóstico por imagem , AVC Isquêmico/cirurgia , Isquemia Encefálica/diagnóstico por imagem , Isquemia Encefálica/cirurgia , Estudos Retrospectivos , LDL-Colesterol , Prognóstico , Acidente Vascular Cerebral/diagnóstico por imagem , Acidente Vascular Cerebral/cirurgia , Trombectomia , Infarto Cerebral/complicações , Resultado do Tratamento
9.
Artigo em Inglês | MEDLINE | ID: mdl-36062178

RESUMO

Objective: The aim of this study is to explore the therapeutic effect of Xingnao kaiqiao acupuncture combined with butylphthalide sodium chloride injection on acute cerebral infarction and its effect on the levels of serum malondialdehyde (MDA), superoxide dismutase (SOD), and glutathione peroxidase (GSH). Methods: 120 patients with acute cerebral infarction who were treated in our hospital from March 2020 to March 2022 and met the inclusion and exclusion criteria were divided into two groups. The control group was treated with sodium butylphthalide chloride injection, and the study group was treated with Xingnao kaiqiao acupuncture combined with sodium butylphthalide chloride injection. Results: After treatment, the levels of neurotransmitters, the TTP and RI and MDA in both groups decreased, and the Qmean, CBV values, and the levels of SOD and GSH increased, and the changes of index in the study group were more significant than those in the control group (P < 0.05). After treatment, the NIHSS score and syndrome score of the two groups decreased, the MMSE score increased, the NIHSS score and syndrome score of the study group decreased more significantly than that of the control group, and MMSE score increased more significantly than that of the control group (P < 0.05). In terms of clinical efficacy, the total effective rate of the study group was higher than that of the control group (P < 0.05). Conclusion: Xingnao kaiqiao acupuncture combined with butylphthalide sodium chloride injection is effective in patients with acute cerebral infarction. It can improve the level of neurotransmitters and cerebral blood flow perfusion and inhibit the abnormal expression of MDA, SOD, and GSH.

10.
Neurol Sci ; 42(9): 3605-3613, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34236554

RESUMO

BACKGROUND: Atherosclerosis is the most common cause of ischemia stroke. Computed tomographic angiography (CTA) and digital subtraction angiography (DSA) are used to evaluate the degree of lumen stenosis. However, these examinations are invasive and can only reveal mild to moderate stenosis. High-resolution magnetic resonance imaging (HRMRI) seems a more intuitive way to show the pathological changes of vascular wall. Hence, we conducted a systematic retrospective study to determine the characteristics of symptomatic plaques in patients with intracranial atherosclerosis on HRMRI and their association with the occurrence and recurrence of ischemic stroke events. METHODS: The PubMed database was searched for relevant studies reported from January 31, 2010, to October 31, 2020. RESULTS: We selected 14 clinical outcome studies. We found that plaque enhancement and positive remodeling on HRMRI indicate symptomatic plaques. Besides, intraplaque hemorrhage and positive remodeling index are closely related to the occurrence of stroke. However, it is still controversial whether the initial enhancement of plaque and the occurrence and recurrence of stroke are related. There is also no significant correlation between vascular stenosis and symptomatic plaque or the occurrence and recurrence of ischemic stroke. CONCLUSION: High-resolution magnetic resonance imaging can be used as an assessment tool to predict the risk of stroke onset and recurrence in patients with atherosclerosis, but further research is also needed.


Assuntos
Isquemia Encefálica , Arteriosclerose Intracraniana , AVC Isquêmico , Placa Aterosclerótica , Acidente Vascular Cerebral , Isquemia Encefálica/complicações , Isquemia Encefálica/diagnóstico por imagem , Isquemia Encefálica/epidemiologia , Humanos , Arteriosclerose Intracraniana/complicações , Arteriosclerose Intracraniana/diagnóstico por imagem , Angiografia por Ressonância Magnética , Imageamento por Ressonância Magnética , Placa Aterosclerótica/diagnóstico por imagem , Estudos Retrospectivos , Acidente Vascular Cerebral/diagnóstico por imagem , Acidente Vascular Cerebral/epidemiologia
11.
Huan Jing Ke Xue ; 42(1): 368-377, 2021 Jan 08.
Artigo em Chinês | MEDLINE | ID: mdl-33372489

RESUMO

Wetting-drying alternation irrigation (WDI) can harvest high grain yield under effective irrigation water saving conditions. However, the kernel cadmium (Cd) content usually exceeds the national standard of 0.20 mg Cd per kg kernel in WDI. Applying a passivating agent with high-efficient repairing capabilities could be a feasible approach to reduce Cd content lower than 0.20 mg·kg-1 in WDI. Therefore, a field experiment was conducted with different irrigation regimes and passivating agents in a mildly Cd-polluted paddy field, of which the irrigation regimes were WDI and traditional flooded irrigation (FI) and the six passivating agents treatments were CK (no passivating agent; T1), slaked lime with 1125 kg·hm-2(T2), 1125 kg slaked lime and 3000 kg biochar per hectare (T3), 1125 kg slaked lime and 3000 kg organic fertilizer per hectare (T4), 1500 kg porous Nano stupalith per hectare (T5), and 1125 kg slaked lime combined with 1500 kg porous Nano stupalith per hectare (T6). Two typical Indica hybrid rice varieties with a high accumulated capacity named cultivar Shenliangyou 1813 and a low accumulated trait named cultivar Liangyou 6206 were utilized. The main reason that Indica hybrid rice cultivars were selected was their higher absorbed and accumulated characteristics than that of Japonica rice. The results indicated that available Cd content of the soil significantly declined with 17.13%-61.01% decreasing amplitude at maturity when compared with pre-transplanting in WDI; however, the reduction was in the range of -43.45%-21.07% for the FI treatment across cultivars and passivating agents treatments. The available Cd content at maturity was significantly greater in FI than in WDI (P<0.05). In contrast, WDI had higher Cd content on stem, leaf, and kernel organs at maturity than with FI treatment of both cultivars and all of the passivating agents (P<0.05). Generally, the T1 treatment had the maximum available Cd content in the soil layer and highest accumulated Cd content on different aboveground organs, followed by the T2, T3, T4, T5, and T6 treatments considering both cultivars and irrigation regimes. The Cd kernel contents were 0.23-0.24 mg·kg-1 and 0.16-0.21 mg·kg-1 for cultivars Shenliangyou 1813 and Liangyou 6206, respectively, in the T6 treatment. The higher Cd kernel content was generally related to a larger Cd content in the stem organ. For the grain yield, no significant differences were observed among cultivars, irrigation regimes, or passivating agents treatments (P>0.05). Under WDI, the kernel Cd content was still slightly higher than 0.20 mg·kg-1 in the T6 treatment (0.24 mg·kg-1 for cultivar Shenliangyou 1813 and 0.21 mg·kg-1 for cultivar Liangyou 6206); however, there is a predictability potential to produce lower than 0.20 mg·kg-1 kernel content in the T6 treatment if a cultivar with low accumulated capacity is used. Thus, the combined mode of the WDI+T6+cultivar with accumulated low Cd content could be considered an optimized cultivation scheme to obtain no Cd contaminated kernels with high grain yield and water-use efficiency in mildly polluted paddy fields.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...