Anatase Sol Prepared from Peroxotitanium Complex Aqueous Solution Containing Niobium or Vanadium

Niobium- or vanadium-doped anatase sols were prepared by hydrothermal treatment of 0.1 mol/dm³ peroxotitanium complex aqueous solutions dissolving 0–10 mol% niobium or vanadium at 100°C for 8 h. Niobium-doping caused the increase of lattice constants of anatase and the shape change of anatase crystal from spindle-like to cubic-like structure, but no change of the optical absorbance. Vanadium-doping caused the decrease of lattice constant of c -axis, the miniaturization of anatase crystal and the increase of optical absorbance at the wavelength from 350–700 nm.     

Preparation of Laminin-apatite-polymer Composites Using Metastable Calcium Phosphate Solutions

A synthetic polymer with a laminin-apatite composite layer on its surface would be useful as a percutaneous device. The preparation of such a composite was attempted in the present study using poly（ ethylene terephthalate ） （PET） and polyethylene （PE） as the synthetic polymer. PET and PE plates and those pretreated with an oxygen plasma were alternately dipped in calcium and phosphate ion solutions, and then immersed in a metastable calcium phosphate solution supplemented with laminin （ LCP solution ）. The PET and PE plates pretreated with an oxygen plasma formed a uniform and continuous layer of a laminin-apatite composite on their surfaces. In contrast, the PET and PE plates that had not been pretreated with an oxygen plasma did not form a continuous layer of a laminin-apatite composite on their surfaces. The hydrophilic functional groups on the PET and PE surfaces introduced by the plasma treatment were responsible for the successful laminin-apatite coruposite coating.     

Pulmonary complications in hematological diseases

A clinical study was conducted to compare the analgesic effect of clonidine with those of sumatriptan and their mixture and their effects on hemodynamics. 40 patients undergoing elective total hysterectomy were randomly divided into 4 groups in terms of the epidurally administered drugs with 10 patients in each group (group C1: clonidine 150 micrograms, group C2: clonidine 75 micrograms, group S: sumatriptan 6 mg and group S + C: clonidine 75 micrograms + sumatriptan 3 mg). MAP, HR, SpO2, VT VAS, VRS and ePDT were measured in the initial 4 h. The demographic data and the doses of intraoperative local anesthetics among the 4 groups were not statistically different. It was found that no significant difference in the pre- and postadministration values of HR, SpO2 and VT. A obvious reduction of MAP appeared in the groups of C1 and C2, but in the other groups the hemodynamical parameters were stable. The groups of C1, C2 and S + C showed significant increase in VAS and VRS, along with increase of ePDT when compared with the pre-drug level. There was no obvious alteration in group S after the drug administration. It was concluded that (1) single use of sumatriptan is ineffective in the dose given in this study; (2) small dose (150 micrograms and 75 micrograms) of clonidine has epidurally analgesic effects; (3) combined use of sumatriptan and clonidine is an acceptable way in epidural analgesia, in terms of its analgesic effect and hemodynamic changes.     

Hot carrier magnetophonon spectroscopy of semiconductors in high magnetic fields up to 40 T

Hot carrier magnetophonon resonances of n-type Si, short channel InP and p-type InSb were investigated in pulsed high magnetic fields up to 40 T. Using a recently developed high resolution technique in pulsed high fields, many new features of the hot carrier-phonon interactions in high magnetic fields were found.     

Electrophysiological elucidation of pathways of intrinsic horizontal connections in rat visual cortex

In single pass perfused rat liver, rapid osmotic water shifts across the plasma membrane in response to hyperosmolar urea were followed by monitoring liver mass and transient concentrating or diluting effects on Na+ concentration in effluent perfusate. Sudden addition or removal of hyperosmolar urea (200mM, resulting in a step change of the perfusate osmolarity from 305 to 505 mosmol/l) had little effect on liver mass or Na+ activity in the effluent perfusate, suggesting that urea equilibrated at a rate similar to that of water across the liver plasma membrane. When, however, phloretin (0.2mM) was present, sudden addition (removal) of urea (200mM) induced within seconds a marked and transient decrease (increase) of both liver mass and effluent Na+ concentration, suggestive of transient osmotic water shifts out of/into the cells. Although to a lesser extent, comparable effects were induced when urea was added/removed in the presence of the phloretin-related phenol compounds 2,4,6-trihydroxyacetophenone (5mM) and 2,4,5-trihydroxybutyrophenone (5mM). Phloretin-induced inhibition of urea export from livers preloaded with [14C]urea was reversible, and no saturation of urea transport was found at concentrations up to 200mM. In contrast to [14C]urea transport, [3H]water transport across the plasma membrane was not affected by phloretin. The data indicate that urea export across the hepatocyte plasma membrane is almost as fast as water export. The urea transport mechanism is sensitive to phloretin and other phenol compounds, works with high capacity and is distinct from the water-transporting system. The regulation of this putative transport mechanism and its relevance for hepatic nitrogen metabolism remain to be established.     

Fate of the chlorine and fluorine in a sub-bituminous coal during pyrolysis and gasification

The fate of the chlorine and fluorine present in a sub-bituminous coal from Indonesia during pyrolysis and gasification has been studied with fixed and entrained bed reactors. The rate profile for HCl evolved in the temperature programmed pyrolysis exhibits the main and shoulder peaks at 480 and 600 °C, respectively. Model experiments and subsequent Cl 2p XPS measurements show that HCl reacts with metal impurities and carbon active sites at 500 °C to be retained as inorganic and organic chlorine forms, from which HCl evolves again at elevated temperatures. It is suggested that the HCl observed in the coal pyrolysis may originate from the above-mentioned chlorine functionalities formed by secondary reactions involving the nascent char. In the CO₂ gasification of the 900 °C char at 1000 °C and 2.5 MPa, any measurable amounts of HCl and HF could not be detected even at a high conversion of 75 wt% (daf), suggesting the accumulation of these halogens in the residual char. When the coal is injected into an O₂-blown, entrained bed gasifier at 1200-1400 °C under 2.6 MPa, the partial oxidation proceeds to a larger extent at a higher O₂/coal ratio, whereas the chlorine and fluorine are enriched in the remaining char, and the extent of the enrichment at the latter stage of gasification is larger with the fluorine. The XPS measurements of the chars reveal the presence of the broad F 1 s peak, which can cover a wide range of binding energies attributable to inorganic and organic fluorine. The halogen enrichment during gasification is discussed in terms of secondary reactions of HCl and HF with char.     

Studies on miscibility in homopolymer/ random copolymer blends by equation of state theory

The miscibility of poly(methyl methacrylate) (PMMA) and styrene-acrylonitrile random copolymers (SAN) blends was investigated on the basis of the Flory—Orwoll—Vrij equation of state theory. To obtain the equation of state parameters (P*, V*_sp, T*: characteristic parameters), the pressure—volume—temperature (PVT) behaviour was measured for PMMA and a series of SANs with various acrylonitrile contents. The exchange energy parameter X_ij was also calculated by fitting the theory to some phase diagrams of PMMA/SAN blends. The Flory—Huggins interaction parameter χ was separated into two contributions based on the equation of state theory for mixtures: the exchange energy term χ_inter and the free volume term χ_free. Both the temperature and copolymer composition dependences of χ_inter and χ_free were estimated by calculations using the equation of state parameters. There exists a region in which χ_inter is negative, leading to a miscibility window in PMMA/SAN blends. However, the immiscibility at high temperatures in the blends cannot be explained only by χ_inter; it is caused by the free volume contribution, χ_free. The miscibility window behaviour in PMMA/SAN blends may be explained within the framework of the equation of state theory.     

Effect of polymer density on polyethylene hollow fiber membrane formation via thermally induced phase separation

Microporous high‐density polyethylene (HDPE) and low‐density polyethylene (LDPE) hollow fiber membranes were prepared from polyethylene–diisodecyl phthalate solution via thermally induced phase separation. Effect of the polyethylene density on the membrane structure and performance was investigated. The HDPE membrane showed about five times higher water permeability than the LDPE membrane because it had the larger pore and the higher porosity at the outer membrane surface. The formation of the larger pore was owing to both the initial larger structure formed by spinodal decomposition and the suppression of the diluent evaporation from the outer membrane surface due to the higher solution viscosity. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 93: 471–474, 2004