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PubMed2001

[Preliminary studies on process and ultramicro-pulverization on pharmacodynamics of Leech].

OBJECTIVE: To compare pharmacodynamics of decoction and powder of Leech; To identify effect of pharmacodynamics of Leech with new methods of process and ultrmicro-pulverization. METHOD: The size of ultramicor-powder of Leech and new method processed Leech is determined by BT-1500 size distributive instrument. It is compared that the pharmacodynamics of Leech decoction and powder as well as ultramicro-powder with new method processed of 1/2 decoction dose by anticoagulation and antithrombus action of mice. The safety of different samples is identified. RESULT: The pharmacodynamics of samples is as ultramicro-powder of Leech with new method processed > ultrmicro-powder of Leech > powder of Leech > decoction of Leech. CONCLUSION: The ultramicro-powder of Leech with new method processed has better pharmacodynamic effect and the smell of Leech is improved.

Animals↗
PubMed2004

Occurrence and volatility of several trace elements in pulverized coal boiler.

The contents of eight trace elements(Mn, Cr, Pb, As, Se, Zn, Cd, Hg) in raw coal, bottom ash and fly ash were measured in a 220 t/h pulverized coal boiler. Factors affecting distribution of trace elements were investigated, including fly ash diameter, furnace temperature, oxygen content and trace elements' characters. One coefficient of Meij was also improved to more directly show element enrichment in combustion products. These elements may be classified into three groups according to their distribution: Group 1: Hg, which is very volatile. Group 2: Pb, Zn, Cd, which are partially volatile. Group 3: Mn, which is hardly volatile. Se may be located between groups 1 and 2. Cr has properties of both group 1 and 3. In addition, the smaller diameter of fly ash, the more relative enrichment of trace elements (except Mn). The fly ash showed different adsorption mechanisms of trace elements and the volatilization of trace elements rises with furnace temperature. Relative enrichments of trace elements(except Mn and Cr) in fly ash are larger than that in bottom ash. Low oxygen content can not always improve the volatilization of trace elements. Pb is easier to form chloride than Cd during coal combustion. Trace elements should be classified in accordance with factors.

Adsorption↗
PubMed1978

Preliminary results of phage typing of coagulase-negative staphylococci with the set of typing phages of Pulverer and co-workers.

120 strains of Staphylococcus epidermidis isolated from clinical material were typed with the set of 16 test phages described by Pulverer et al. (1975). 58 (48%) strains were typable with RTD and additionally 12 strains with 100 times RTD. The pattern Ph10/U14/U16 was observed most common (36 strains), followed by the pattern U14/U16 (11 strains). One strain showed lysis reactions with all typing phages. With 61 strains phage U14 gave a lysis whereas phage U20 reacted only with 4 strains. The S. epidermidis phages were not specific for this species, at least some of these showed lysis reactions with S. aureus strains. The lysis pattern most often observed was Ph10/U14/U16. There was no correlation between the patterns given by the S. aureus test phages and those by the S. epidermidis phages.

Bacteriophage Typing↗
PubMed1984

Some biological properties of preserved bovine fascia enriched with pulverized calf cartilage.

The immunogenicity of trypsinized and radiation-sterilized bovine fascia enriched with pulverized calf cartilage was tested by the regional lymph node blastic cell reaction. The influence of these grafts on the adjacent tissue and on regeneration processes was examined histologically. After transplantation into mice the grafts stimulated growth of new connective tissue and did not evoke an increase of the blastic cell reaction in the regional lymph nodes.

Animals↗
PubMed1992

Electron spin resonance studies of dental composites: effects of irradiation time, decay over time, pulverization, and temperature variations.

Polymerization induced by UV-VIS light of composite dental materials produces a solid matrix within which terminal radicals of non-polymerized monomers remain trapped. Electron Spin Resonance (ESR) allowed three different types of radicals to be identified. The analysis of ten normally available commercial products gave information on: (1) the propagation of the conversion reaction as a result of exposure to light; (2) the time necessary for the decay of each type of radical; and (3) the variations with temperature and the effects of shattering on the materials under study. The presence of inorganic filling material slowed the process of polymerization, while it accelerated the decay of radicals. It was suggested that the nature of these processes depended on the composition of the base resin materials, whereas it did not depend on the sizes of the filler particles. Moreover, the complete propagation of the conversion reaction needed a period of light exposure greater than that currently suggested by the manufacturers. The structural stability and the resistance of the composites were confirmed by both the long period of decay and the high temperatures needed to overcome the potential barrier for starting the radical decay process. Finally, the composite shattering investigation indicated that particles removed by surface abrasion experience rapid radical decay, thus reducing the possibility of harmful effects on internal organs.

Composite Resins↗
PubMed2005

Chemical component mapping of pulverized toner by scanning transmission X-ray microscopy.

Toners are micron scale polymer particles constructed of several kinds of resin, pigment, wax, etc. Transmission electron microscopy (TEM) is used for observation of the dispersion of the component materials in toners, but TEM images cannot identify simultaneously all components. Scanning transmission X-ray microscopy (STXM) not only provides simultaneous observation of spatial distributions of wax, resin and carbon black in toners, but it also provides detailed, quantitative, chemical information about the wax and resin environments through chemical component maps derived from multiple energy image sequences. The capabilities of STXM for toner analysis are illustrated by results of a study of a toner for black/white copy/print applications.

Journal Article↗
PubMed2001

Monitoring the species of arsenic, chromium and nickel in milled coal, bottom ash and fly ash from a pulverized coal-fired power plant in western Canada.

The concentration of As, Cr and Ni and their speciation (As3+;5+, Cr3+;6+ and Ni0;2+) in milled coal, bottom ash and ash collected by electrostatic precipitator (ESP) from a coal fired-power plant in western Canada were determined using HGAAS, ICP-AES and XANES. The chemical fractionation of these elements was also determined by a sequential leaching procedure, using deionized water, NH4OAC and HCI as extracting agents. The leachate was analyzed by ICP-AES. Arsenic in the milled coal is mostly associated with organic matter, and 67% of this arsenic is removed by ammonium acetate. This element is totally removed from milled coal after extraction with HCI. Arsenic occurs in both the As3+ and the As5+ oxidation states in the milled coal, while virtually all (>90%) of the arsenic in bottom ash and fly ash appears to be in the less toxic arsenate (As5+) form. Both Ni and Cr in the milled coal are extracted by HCI, indicating that water can mobilize Ni and Cr in an acidic environment. The chromium is leached by water from fly ash as a result of the high pH of the water, which is induced during the leaching. Ammonium acetate removes Ni from bottom ash through an ion exchange process. Chromium in milled coal is present entirely as Cr3+, which is an essential human trace nutrient. The Cr speciation in bottom ash is a more accentuated version of the milled coal and consists mostly of the Cr3+ species. Chromium in fly ash is mostly Cr3+, with significant contamination by stainless-steel from the installation itself.

Air Pollution↗
PubMed2003

Behavior of fluorine and chlorine in Spanish coal fired power plants with pulverized coal boilers and fluidized bed boiler.

Behavior and contents of fluorine and chlorine in coal feedstock, combustion wastes (slag and fly ash) and emissions were studied in five conventional coal fired power plants and in a fluidized bed coal power plant. The halide levels found in the used coal were quite low. Mass balances and emission factors were calculated. The volatility of these elements makes the gaseous emission the main target between the residues. The influence of combustion parameters is not clearly established. Several analytical techniques (ion selective electrodes, capillary electrophoresis and ion chromatography) are employed to determinate the halide concentration in the different samples taken in the power plants studied (coal, slag, fly ash and flue gases).

Chlorine↗
PubMed2000

Comparison of particle size distributions and elemental partitioning from the combustion of pulverized coal and residual fuel oil.

U.S. Environmental Protection Agency (EPA) research examining the characteristics of primary PM generated by the combustion of fossil fuels is being conducted in efforts to help determine mechanisms controlling associated adverse health effects. Transition metals are of particular interest, due to the results of studies that have shown cardiopulmonary damage associated with exposure to these elements and their presence in coal and residual fuel oils. Further, elemental speciation may influence this toxicity, as some species are significantly more water-soluble, and potentially more bio-available, than others. This paper presents results of experimental efforts in which three coals and a residual fuel oil were combusted in three different systems simulating process and utility boilers. Particle size distributions (PSDs) were determined using atmospheric and low-pressure impaction as well as electrical mobility, time-of-flight, and light-scattering techniques. Size-classified PM samples from this study are also being utilized by colleagues for animal instillation experiments. Experimental results on the mass and compositions of particles between 0.03 and > 20 microns in aerodynamic diameter show that PM from the combustion of these fuels produces distinctive bimodal and trimodal PSDs, with a fine mode dominated by vaporization, nucleation, and growth processes. Depending on the fuel and combustion equipment, the coarse mode is composed primarily of unburned carbon char and associated inherent trace elements (fuel oil) and fragments of inorganic (largely calcium-alumino-silicate) fly ash including trace elements (coal). The three coals also produced a central mode between 0.8- and 2.0-micron aerodynamic diameter. However, the origins of these particles are less clear because vapor-to-particle growth processes are unlikely to produce particles this large. Possible mechanisms include the liberation of micron-scale mineral inclusions during char fragmentation and burnout and indicates that refractory transition metals can contribute to PM < 2.5 microns without passing through a vapor phase. When burned most efficiently, the residual fuel oil produces a PSD composed almost exclusively of an ultrafine mode (approximately 0.1 micron). The transition metals associated with these emissions are composed of water-soluble metal sulfates. In contrast, the transition metals associated with coal combustion are not significantly enriched in PM < 2.5 microns and are significantly less soluble, likely because of their association with the mineral constituents. These results may have implications regarding health effects associated with exposure to these particles.

Air Pollution↗
PubMed2004

Differential pulmonary inflammation and in vitro cytotoxicity of size-fractionated fly ash particles from pulverized coal combustion.

Exposure to airborne particulate matter (PM) has been associated with adverse health effects in humans. Pulmonary inflammatory responses were examined in CD1 mice after intratracheal instillation of 25 or 100 microg of ultrafine (< 0.2 microm), fine (< 2.5 microm), and coarse (> 2.5 microm) coal fly ash from a combusted Montana subbituminous coal, and of fine and coarse fractions from a combusted western Kentucky bituminous coal. After 18 hr, the lungs were lavaged and the bronchoalveolar fluid was assessed for cellular influx, biochemical markers, and pro-inflammatory cytokines. The responses were compared with saline and endotoxin as negative and positive controls, respectively. On an equal-mass basis, the ultrafine particles from combusted Montana coal induced a higher degree of neutrophil inflammation and cytokine levels than did the fine or coarse PM. The western Kentucky fine PM caused a moderate degree of inflammation and protein levels in bronchoalveolar fluid that were higher than the Montana fine PM. Coarse PM did not produce any significant effects. In vitro experiments with rat alveolar macrophages showed that of the particles tested, only the Montana ultrafine displayed significant cytotoxicity. It is concluded that fly ash toxicity is inversely related with particle size and is associated with increased sulfur and trace element content.

Animals↗