Ethanol production from raw starch by a recombinant yeast having saccharification and fermentation activities

In order to develop a method for converting raw starch into ethanol efficiently, direct fermentation of ozonized raw starch using a recombinant yeast was investigated. Ozonolysis was carried out as a pretreatment to convert raw starch into ethanol rapidly and efficiently, and then the effect of the ozone degradation conditions on the degree of polymerization and the amount of amylose in a raw starch was determined. Since the degree of polymerization was low and the amount of amylose was high, raw starch treated with an ozone concentration of 40 gm^?3 and an ozonation time of 30 min was the material chosen for alcohol fermentation. Though the recombinant yeast could not convert the untreated raw starch, it converted the soluble starch and the ozonized raw starch at a comparatively high yield into ethanol. About 56% of the ozonized raw starch decomposed, and the ethanol concentration obtained from the ozonized raw starch was markedly greater than that obtained from untreated raw starch. The dynamic behavior of cell growth, substrate degradation, and ethanol production was examined in a continuous culture under various dilution rates, and the optimal dilution rate, ie 0.15 h^?1, was determined for maximizing the ethanol productivity (amount of ethanol produced per unit time). © 2002 Society of Chemical Industry     

Microfluidic Spinning of Cell‐Responsive Grooved Microfibers

Engineering living tissues that simulate their natural counterparts is a dynamic area of research. Among the various models of biological tissues being developed, fiber‐shaped cellular architectures, which can be used as artificial blood vessels or muscle fibers, have drawn particular attention. However, the fabrication of continuous microfiber substrates for culturing cells is still limited to a restricted number of polymers (e.g., alginate) having easy processability but poor cell–material interaction properties. Moreover, the typical smooth surface of a synthetic fiber does not replicate the micro‐ and nanofeatures observed in vivo, which guide and regulate cell behavior. In this study, a method to fabricate photocrosslinkable cell‐responsive methacrylamide‐modified gelatin (GelMA) fibers with exquisite microstructured surfaces by using a microfluidic device is developed. These hydrogel fibers with microgrooved surfaces efficiently promote cell encapsulation and adhesion. GelMA fibers significantly promote the viability of cells encapsulated in/or grown on the fibers compared with similar grooved alginate fibers used as controls. Importantly, the grooves engraved on the GelMA fibers induce cell alignment. Furthermore, the GelMA fibers exhibit excellent processability and could be wound into various shapes. These microstructured GelMA fibers have great potential as templates for the creation of fiber‐shaped tissues or tissue microstructures.     

Determination of sucralose in foods by HPLC using pre-column derivatization

The development of a sensitive pre-column derivatization high-performance liquid chromatography (HPLC) method for determination of sucralose is reported. Sucralose is converted into a strongly ultraviolet (UV)-absorbing derivative, possessing strong absorption at 260 nm, by treatment with p-nitrobenzoyl chloride (PNBCl). Homogenized samples were dialyzed and washed with a Bond Elut ENV cartridge, then the eluate was evaporated to dryness and the residue was derivatized. Subsequently, the sucralose derivative was purified with hexane-ethyl actate (9:1) in a silica cartridge, and then the sucralose derivative was eluted with acetone. HPLC was performed on a phenyl column, using acetonitrile-water (73:27) as a mobile phase with UV detection (260 nm). The calibration curve was linear in the range of 1 microgram/mL to 50 micrograms/mL of sucralose. The recoveries of sucralose from eight kinds of foods spiked at the levels of 0.20 and 0.05 g/kg of sucralose were more than 76.2% with SD values in the range from 0.90% to 4.31%. The quantitative limit of the developed method was 0.005 g/kg for sucralose in samples.     

Prophylactic effect of papaverine prolonged-release pellets on cerebral vasospasm in dogs

OBJECTIVE: A drug delivery system using copoly(lactic/glycolic acid) was developed for the intracranial administration of papaverine. A rod-shaped implant prepared by a heat compression method was tested to determine its efficacy in preventing cerebral vasospasm in dogs. METHODS: Sixteen dogs were randomly assigned to one of two groups, i.e., placebo or papaverine. Control angiography was performed, followed by right craniectomy and the induction of subarachnoid hemorrhage by the placement of a clot in the Sylvian fissure. Two pellets, containing either 25 mg of papaverine or no papaverine, were placed in the cistern. In in vitro studies, 56% of the actual papaverine loading was released in the first 4 days and 78% within 8 days. On Day 7, angiography was repeated and the animals were killed. A similar experiment using low-dose pellets containing 5 mg of papaverine, half of which was released within 7 days, was performed with 16 mongrel dogs. RESULTS: There were significant differences between the papaverine- and placebo-treated groups in the reductions of vessel diameters of the internal carotid, middle cerebral, and anterior cerebral arteries on the clot side. The mean concentration of papaverine in the clot was 4.5 x 10(-4) mol/L. The low-dose pellet failed to prevent cerebral vasospasm, although the mean concentration of papaverine in the clot was 2.3 x 10(-5) mol/L. CONCLUSION: A prolonged-release preparation of papaverine that could be implanted intracranially at the time of surgery prevented vasospasm significantly while maintaining an appropriate concentration of papaverine in the cistern.     

Reference values for bisphosphoglycerate mutase protein content and specific activity in human erythrocytes

Cytomegalovirus (CMV) gastritis has been reported in transplant patients. Symptoms are considered nonspecific, and gastroscopy with biopsy is usually performed to establish the diagnosis. Three patients are described here 1 to 3 months after solid organ transplantation, with primary CMV gastritis, confirmed by gastroscopy, histopathologic examination and cultures. The clinical presentation in all three cases was sharp epigastric pain that decreased in a supine position, increased while sitting and further increased when standing or walking. The epigastric pain completely resolved after treatment with ganciclovir. To the best of our knowledge, such postural epigastric pain has not been described as a specific symptom in any other clinical entity and may be a unique sign of primary CMV gastritis.     

Fe-sapphire and C-Fe-sapphire interactions and their effect on the growth of single-walled carbon nanotubes by chemical vapor deposition

We previously reported that the quantity of single-walled carbon nanotubes grown on Fe-coated sapphire by chemical vapor deposition depended on the crystallographic faces of sapphires. In this report, we show that the interaction of Fe, sapphire, and carbon depended on the sapphire faces. We deduce that the quantity of Fe available to catalyze the growth of single-walled carbon nanotubes was suppressed by the formation of Fe-Al alloys and whether the Fe-Al alloys were formed on Fe-coated sapphire or not depended on the sapphire-surface structure.     

Oxygen-Deficient Anatase Precipitated from High-Temperature Plasma

Feeding atomized aqueous solutions containing TiCl₄ into an argon high-temperature inductively coupled plasma (ICP) resulted in the formation of mixtures of white and blue particles. The mixtures consisted of anatase and an extra phase of rutile. Adding oxygen to the ICP led to the production of a single phase of white anatase. The blue particles could be characterized as oxygen-deficient anatase. Electrophoretic mobility measurements indicated that Na+ participated in determining the surface potential of the mixtures. The oxygen defects may provide the adsorption sites to Na+.