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We demonstrate a non-contact trapping of a yeast cell by an optical fiber probe with a micron-size concave cavity both theoretically and experimentally. We fabricate the optical fiber tip with a micron-size concave cavity by the improved tube etching method. The size of the concave cavity can be controlled by the etching parameters, such as the etching time, the etching solution, and so on. The output fields from the fiber tips with concave cavities of two geometrical sizes (microns and tens of microns) are computed and analyzed. Then the optical forces on a yeast cell by these concave fiber tips (CFTs) are calculated and discussed. The theoretical results predicate that a micron-size CFT can be used for non-contact trapping of a yeast cell. We observe the non-contact trapping of a yeast cell by a micron-size CFT in the experiments and measure the trapping forces. The optical trapping and manipulation based on these micron-size CFTs may provide versatile applications in bio-science and medical research. • A non-contact trapping of a yeast cell has been observed by a micron-size CFT. • A micron-size CFT can be fabricated by the improved tube etching method. • The impacts of the cavity size on the optical trapping have been investigated. [ABSTRACT FROM AUTHOR]

Abstract: Silver niobate (AgNbO3) with different morphologies is obtained by annealing the precursors prepared at different temperatures by solvothermal method at 800°C. Scanning electron microscope images of the samples show the formation process of the morphologies. The weakest photovoltaic and the highest photocatalytic properties of the sample obtained from the precursors prepared at 190°C are possibly caused by the synergetic effects between several kinds of particles, and between AgNbO3 and Nb2O5. Both the temperature and the amount of Nb2O5 are crucial for the morphologies, the photoelectric and photocatalytic properties of the samples. [Copyright &y& Elsevier]

Abstract: Silver antimonite samples with different Ag/Sb ratios were prepared via ion exchange method through the mediator of silver proton-exchanged compounds. With the rise in the ratio of Ag to Sb in the samples, the optical band gap decreases due to the increasing contribution of Ag4d to the valence band; the surface photovoltage decreases and photocatalytic activity increases due to surface states related to the Sb3+ in the samples. The present results indicate that appropriate amount of Sb3+ is favorable for improving the photocatalytic activity under visible light irradiation. [Copyright &y& Elsevier]

Abstract: N-doped TiO2/C3N4 composite samples were synthesized by heating the mixture of the hydrolysis product of TiCl4 and C3N4 at different weight ratios. The samples were characterized by X-ray diffraction (XRD), Raman spectrum, UV–vis absorption spectrum, photoluminescence spectrum, X-ray photon electron spectrum (XPS) and surface photovoltage spectrum (SPS). The XRD and Raman results indicate that the introduction of C3N4 could inhibit the formation of rutile TiO2. The composite samples show slight visible light absorption due to the introduction of C3N4. The XPS result reveals that some amount of nitrogen is doped into TiO2, and C3N4 exists in the composite sample. The intensities of the SPS signal in the composite samples decrease with the rise in the amount of C3N4 in the samples. The photocatalytic activity was evaluated from the Rhodamine B (RhB) degradation under fluorescence light irradiation. The composite samples show significantly enhanced photocatalytic activities and the RhB self-sensitized photodegradation in this system was observed by measuring the photocurrent in the dye sensitized solar cell using the composite as the working electrode. [Copyright &y& Elsevier]

Abstract: NaNbO3, (AgNbO3)0.5(NaNbO3)0.5 and AgNbO3 films on FTO conducting glass substrates were fabricated by pulsed laser deposition at 973K for 1h under 10Pa oxygen pressure with the laser energy of 400mJ. The energy band structure and photoelectrochemical behavior were investigated by measuring the flatband potential (V fb) and photocurrent. The optical band gaps for NaNbO3, (AgNbO3)0.5(NaNbO3)0.5 and AgNbO3 are 3.50, 3.25 and 2.93eV, respectively. And the V fb for the NaNbO3, (AgNbO3)0.5(NaNbO3)0.5 and AgNbO3 films are −0.91, −0.76 and −0.88V (vs. Ag/AgCl), respectively, indicating that the conduction band bottom of (AgNbO3)0.5(NaNbO3)0.5 is more positive than those of NaNbO3 and AgNbO3, and the valence band top becomes more positive in order of AgNbO3, (AgNbO3)0.5(NaNbO3)0.5 and NaNbO3. The AgNbO3 film shows the largest photocurrent density due to the more light harvesting, the relative higher donor density and large contact surface area between the electrode and the electrolyte solution. The (AgNbO3)0.5(NaNbO3)0.5 film shows lowest photocurrent due to lower donor density. [Copyright &y& Elsevier]

A procedure is suggested to separating a minimum-boiling azeotrope of toluene and ethanol via heat integration pressure swing distillation (PSD), and an optimized separation configuration is obtained via taking the minimization of the total annual cost (TAC) as an objective function. The result demonstrates that PSD with heat integration is more economical than conventional PSD without heat integration. Based on steady-state simulation results, several control structures were explored using Aspen Dynamics. The results indicate that the composition/temperature cascade control structure and the pressure-compensated temperature control of a PSD process with partial heat integration with stage 21 selected as the control stage in the low pressure column can handle disturbances well. As for the PSD with full heat integration, stage 20 of the low pressure column can act as the control stage because of its more efficient controllability under feed flow rate and feed composition disturbances. [ABSTRACT FROM AUTHOR]

Perioperative neurocognitive disorder (PND) is a common complication of elderly patients after surgery and lacks effective prevention and treatment measures. We investigated the effect and mechanism of gastrodin (GAS), a natural plant ingredient, on postoperative cognition induced by laparotomy in aged mice. Male aged (18 months) mice were subjected to laparotomy and orally treated with GAS (25, 50, and 100 mg/kg) 3 weeks before surgery and 1 week after surgery. In addition, some male aged (18 months) mice were subjected to viral vector or GSK-3β expression virus injection followed by laparotomy with or without 100 mg/kg GAS treatment. GAS improved learning and memory in aged mice after surgery. Surgery increased the levels of pro-inflammatory factors (TNF-α, IL-1β and IL-6) and decreased the level of an anti-inflammatory factor (IL-10) in the mouse hippocampus, and these changes were reversed by GAS treatment. GAS also suppressed the activation of microglia. GAS inhibited the phosphorylation of GSK-3β and Tau. Furthermore, surgery induced more serious cognitive dysfunction, inflammatory factors, activation of microglia, and phosphorylation of GSK-3β and Tau in GSK-3β overexpressing aged mice. The improvement of learning and memory, the reduction of inflammation and microglia activation, and the suppression of GSK-3β and Tau phosphorylation by GAS were prevented when GSK-3β was overexpressed in aged mice subjected to surgery. Our finding suggested that GAS exerts neuroprotective effects in aged mice subjected to laparotomy by suppressing neuroinflammation and GSK-3β and Tau phosphorylation. Thus, these findings suggest that GAS may be a promising agent for PND. [ABSTRACT FROM AUTHOR]