RESUMO
The capability of noble metal nanoparticles (NPs) as efficient charge transfer mediators to stimulate Schottky-junction-triggered charge flow in multifarious photocatalysis has garnered enormous attention in the past decade. Nevertheless, fine-tuning and controllable fabrication of a directional charge transport channel in metal/semiconductor heterostructures via suitable interface engineering is poorly investigated. Here, we report the progressive fabrication of a tailor-made directional charge transfer channel in Pt nanoparticles (NPs)-inlaid WO3 (Pt-WO3) nanocomposites via an efficient electrostatic layer-by-layer (LbL) self-assembly integrated with a thermal reduction treatment, by which oppositely charged metal precursor ions and polyelectrolyte building blocks were intimately and alternately assembled on the WO3 nanorods (NRs) by substantial electrostatic interaction. LbL self-assembly buildup and in situ self-etching-induced structural variation of WO3 NRs to a microsized superstructure occur simultaneously. We found that such exquisitely crafted Pt-WO3 nanocomposites exhibit conspicuously enhanced and versatile photoactivities for nonselective mineralizing of organic dye pollution and reduction of heavy metal ions at ambient conditions under both visible and simulated sunlight irradiation, demonstrating a synergistic effect. This is attributed to the imperative contribution of Pt NPs as electron traps to accelerate the directional high-efficiency electron transport from WO3 to Pt NPs, surpassing the confinement of electron transfer kinetics of WO3 owing to low conduction level. More intriguingly, photoredox catalysis can also be triggered simultaneously in the same reaction system. The primary in situ produced active species in the photocatalytic reactions were specifically analyzed, and underlying photocatalytic mechanisms were determined. Our work would provide a universal synthesis strategy for constructing various metal-decorated semiconductor nanocomposites for widespread photocatalytic utilizations.
RESUMO
OBJECTIVE: To compare the clinical efficacy between scalp acupuncture electrical stimulation and routine scalp acupuncture for motor aphasia in subacute stage of cerebral infarction. METHODS: A total of 54 patients with motor aphasia in subacute stage of cerebral infarction were randomly divided into an observation group (27 cases, 1 case dropped off) and a control group (27 cases, 2 cases dropped off ). Both groups were treated with routine medication and language training. In the observation group, scalp acupuncture was given at bilateral lower 2/5 of the parietal and temporal anterior oblique line and temporal frontline; after the arrival of qi, the electrical stimulation with disperse-dense wave was given at the affected side and continuous wave was given at healthy side. The control group was treated with routine scalp acupuncture at lower 2/5 of the parietal and temporal anterior oblique line and temporal frontline of the affected side, once a day, five times as a course, totaling two courses of treatment. The aphasia battery of Chinese (ABC) score and Boston diagnostic aphasia examination (BDAE) grade were observed before and after treatment. The levels of oxygenated hemoglobin (HbO2), deoxyhemoglobin (D-Hb) and total hemoglobin (T-Hb) in local cerebral cortex of the two groups were measured in real time using functional near-infrared spectroscopy (fNIRS) before and after treatment. The clinical efficacy of the two groups was compared. RESULTS: After treatment, the scores of listening comprehension, retelling, naming, spontaneous conversation and BDAE grade in the two groups were improved compared with those before treatment (P<0.01, P<0.05), and those in the observation group were better than the control group (P<0.05). Compared before treatment, the levels of HbO2 and T-Hb were increased (P<0.01), and the levels of D-Hb were decreased (P<0.01) after treatment in the two groups. The levels of HbO2 and T-Hb in the observation group were higher than those in the control group (P<0.05), and the level of D-Hb was lower than that in the control group (P<0.05). The total effective rate was 92.3% (24/26) in the observation group, which was higher than 84.0% (21/25) in the control group (P<0.05). CONCLUSION: The scalp acupuncture electrical stimulation could improve cerebral circulation, activate specific functional areas of cerebral cortex, and promote the reconstruction and recovery of brain language function. Its curative effect is better than conventional scalp acupuncture.