Peptide Self-Assembled Biofilm with Unique Electron Transfer Flexibility for Highly Efficient Visible-Light-Driven Photocatalysis.

Inspired by natural photosynthesis, biomaterial-based catalysts are being confirmed to be excellent for visible-light-driven photocatalysis, but are far less well explored. Herein, an ultrathin and uniform biofilm fabricated from cold-plasma-assisted peptide self-assembly was employed to support Eosin Y (EY) and Pt nanoparticles to form an EY/Pt/Film catalyst for photocatalytic water splitting to H2 and photocatalytic CO2 reduction with water to CO, under irradiation of visible light. The H2 evolution rate on EY/Pt/Film is 62.1 µmol h(-1), which is about 5 times higher than that on Pt/EY and 1.5 times higher than that on the EY/Pt/TiO2 catalyst. EY/Pt/Film exhibits an enhanced CO evolution rate (19.4 µmol h(-1)), as compared with Pt/EY (2.8 µmol h(-1)) and EY/Pt/TiO2 (6.1 µmol h(-1)). The outstanding activity of EY/Pt/Film results from the unique flexibility of the biofilm for an efficient transfer of the photoinduced electrons. The present work is helpful for designing efficient biomaterial-based catalysts for visible-light-driven photocatalysis and for imitating natural photosynthesis.

[Efficacy of continuous propofol infusion via the common carotid artery for general anesthesia].

OBJECTIVE: To investigate the efficacy of continuous propofol infusion via the common carotid artery for general anesthesia. METHODS: Forty adult patients scheduled for abdominal surgery were randomly assigned into 2 groups to receive propopol via the common carotid artery (IC group, n=20) or via the median cubital vein (IV group, n=20). Anesthesia was induced with intravenous administration of drugs and maintained with continuous propofol infusion via the common carotid artery or the median cubital vein, with the CSI stabilized at 40-/+5 till the end of the operation. During the anesthesia, intravenous injection of fentanyl (3 microg.kg(-1).h(-1)) and vecuronium (50 microg.kg(-1).h(-1)) were given intermittently to maintain the analgesia and muscular relaxation. The dose of propofol used, hemodynamics and recovery of the patients were observed. RESULTS: The dose of propofol used during the surgery to maintain a CSI of 40-/+5 was significantly lower in group IC and than in group IV (2.57-/+0.67 vs 5.72-/+1.37 mg.kg(-1).h(-1), P<0.01). In group IC, the blood pressure was elevated in more than half of the patients and in some cases, the elevation exceeded one third of baseline value and needed intervention with hypotensive drugs. In the IV group, the patients' blood pressure remained stable and varied within the amplitude of 15% of the baseline level. Recovery of spontaneous breathing and consciousness was more quickly in group IC than in group IV (P<0.05). CONCLUSION: Loss of consciousness and nervous reflex can be achieved with propofol infusion via the common carotid artery, which reduces propofol dose by about 50% in comparison with intravenous infusion and allows more rapid recovery of spontaneous breath and consciousness.

[Effects of carotid arterial and intravenous propofol administration for electrocerebral silence on circulation and respiration in dogs].

OBJECTIVE: To compare the effects of common carotid artery and femoral vein administration of propofol for electrocerebral silence (ES) on circulatory and respiratory function and the dosage of propofol required during ES in dogs. METHODS: Eight dogs were anesthetized by common carotid arterial and femoral vein administration of propofol for ES for 1 h. The time of consciousness loss and recovery, dose of propofol during ES, mean arterial pressure, heart rate, respiration rate, end-tidal carbon dioxide, SpO2, cerebral state index (CSI) and anal temperature were continuously monitored. Changes in the outcome variables were analyzed at 7 time points, namely the baseline, upon loss of consciousness, at 10 s, 30 min and 1 h of CSI=0, and recovery of CSI and consciousness. RESULTS: Carotid artery propofol administration produced ES with only half of the dose for intravenous administration. Compared with the baseline values, the mean artery pressure and respiration rate remained unchanged or decreased transiently during ES with carotid artery propofol administration. In contrast, intravenous propofol administration resulted in systemic hypotension and severe respiratory depression. CONCLUSION: Carotid artery propofol administration produces ES with a much smaller dose than intravenous propofol administration without causing systemic hypotension or respiratory depression.