Hierarchical, titania-coated, nanofibrous, carbon hybrid materials were fabricated by employing natural cellulosic substances (commercial filter paper) as a scaffold and carbon precursor. Ultrathin titania films were firstly deposited by means of a surface sol-gel process to coat each nanofiber in the filter paper, and successive calcination treatment under nitrogen atmosphere yielded the titania-carbon composite possessing the hierarchical morphologies and structures of the initial paper. The ultrathin titania coating hindered the coalescence effect of the carbon species that formed during the carbonization process of cellulose, and the original cellulose nanofibers were converted into porous carbon nanofibers (diameters from tens to hundreds of nanometers, with 3-6 nm pores) that were coated with uniform anatase titania thin films (thickness approximately 12 nm, composed of anatase nanocrystals with sizes of approximately 4.5 nm). This titania-coated, nanofibrous, carbon material possesses a specific surface area of 404 m(2) g(-1), which is two orders of magnitude higher than the titania-cellulose hybrid prepared by atomic layer deposition of titania on the cellulose fibers of filter paper. The photocatalytic activity of the titania-carbon composite was evaluated by the improved photodegradation efficiency of different dyes in aqueous solutions under high-pressure, fluorescent mercury-lamp irradiation, as well as the effective photoreduction performance of silver cations to silver nanoparticles with ultraviolet irradiation.

An epizootic in pond cultured sea bass, Lateolabrax japonicus, was caused by Nocardia sp. in Taiwan, in September and October 1997. The cumulative mortality within 1 month was 17.5% (3500 out of 20 000 fish) and diseased fish were 7 months old with total lengths from 25 to 30 cm. Multiple, yellowish white nodules, 0.1–0.2 cm in diameter, were scattered in the gill, heart, liver, spleen and kidney. Histopathologically, typical granulomatous lesions appeared in those organs. The morphology of isolated bacteria from brain heart infusion (BHI) medium or Lowenstein–Jensen medium (LJM) were bead‐like filaments, as shown by Ziehl‐Neelsen's (ZN) staining method. The gross lesion and histopathological changes found in experimentally infected fish were similar to those in naturally infected fish. Based on the growth characteristics, morphological and biochemical properties of the bacterium, and histopathological changes, the isolated bacteria were identified as Nocardiaseriolae. This is the first report of N. seriolae‐infected sea bass in aquaculture.

Creating actuators capable of mechanical motion in response to external stimuli is a key for design and preparation of smart materials. The lifetime of such materials is limited by their eventual wear. Here, self‐healable and adhesive actuating materials are demonstrated by taking advantage of the solvent responsive of weak polyelectrolyte multilayers consisting of branched poly(ethylenimine)/poly(acrylic acid) (BPEI/PAA). BPEI/PAA multilayers are dehydrated and contract upon contact with organic solvent and become sticky when wetted with water. By constructing an asymmetric heterostructure consisting of a responsive BPEI/PAA multilayer block and a nonresponsive component through either layer‐by‐layer assembly or the paste‐to‐curl process, smart films that actuate upon exposure to alcohol are realized. The curl degree, defined as degrees from horizontal that the actuated material reaches, can be as high as ≈228.9°. With evaporation of the ethanol, the curled film returns to its initial state, and water triggers fast self‐healing extends the actuator's lifetime. Meanwhile, the adhesive nature of the wet material allows it to be attached to various substrates for possible combination with hydrophobic functional surfaces and/or applications in biological environments. This self‐healable adhesive for controlled fast actuation represents a considerable advance in polyelectrolyte multilayers for design and fabrication of robust smart advanced materials.

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Polyelectrolyte multilayers (PEMs), assembled from weak polyelectrolytes, have often been proposed for use as smart or responsive materials. However, such response to chemical stimuli has been limited to aqueous environments with variations in ionic strength or pH. In this work, a large in magnitude and reversible transition in both the swelling/shrinking and the viscoelastic behavior of branched polyethylenimine/poly(acrylic acid) multilayers was realized in response to exposure with various polar organic solvents (e.g., ethanol, dimethyl sulfoxide, and tetrahydrofuran). The swelling of the PEM decreases with an addition of organic content in the organic solvent/water mixture, and the film contracts without dissolution in pure organic solvent. This large response is due to both the change in dielectric constant of the medium surrounding the film as well as an increase in hydrophobic interactions within the film. The deswelling and shrinking behavior in organic solvent significantly enhances its elasticity, resulting in a stepwise transition from an initially liquid-like film swollen in pure water to a rigid solid in pure organic solvents. This unique and recoverable transition in the swelling/shrinking behaviors and the rheological performances of weak polyelectrolyte multilayer film in organic solvents is much larger than changes due to ionic strength or pH, and it enables large scale actuation of a freestanding PEM. The current study opens a critical pathway toward the development of smart artificial materials.