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  • 1
    Electronic Resource
    Electronic Resource
    Water-air transfer resistance for ammonia from flooded rice (1988)
    Springer
    Journal of atmospheric chemistry 6 (1988), S. 133-147 
    Details
    ISSN: 1573-0662
    Keywords: Ammonia loss ; energy balance ; micrometeorology ; water-air transfer
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Geosciences
    Notes: Abstract Vertical flux densities of ammonia, water vapour and sensible heat were measured over a flooded rice field in China following the application of ammonium bicarbonate fertilizer. Aqueous and gaseous phase transfer resistances for ammonia were deduced from these measurements. The aqueous phase resistance was maximal in the morning and least in the afternoon. Stable stratification of the floodwater immediately adjacent to the air-water interface was observed during the morning when evaporation rates were low, and may be responsible for inhibiting the transfer of ammonia to the atmosphere.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00048336
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  • 2
    Electronic Resource
    Electronic Resource
    Processes of nitrogen loss from fertilizers applied to flooded rice fields on a calcareous soil in north-central China (1988)
    Springer
    Nutrient cycling in agroecosystems 18 (1988), S. 101-115 
    Details
    ISSN: 1573-0867
    Keywords: Ammonia loss ; denitrification ; nitrogen balance ; algal growth ; transfer processes
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Losses of nitrogen were investigated after applications of ammonium bicarbonate and urea to flooded rice at transplanting. Ammonia (NH3) volatilization was determined by direct micrometeorological methods, and total loss of fertilizer nitrogen (N) was measured by15N balance. All the loss appeared to be in gaseous forms, since there was no evidence of leaching and runoff was prevented. The difference between N loss and NH3 loss was thus assumed to be denitrification loss. Both NH3 volatilization and denitrification losses were large, being 39% and 33%, respectively, of the ammonium bicarbonate N, and 30% and 33%, respectively, of the urea N applied by farmers' methods. Ammonia fluxes from the field fertilized with ammonium bicarbonate were very high for two days, and then declined rapidly as the NH3 source in the floodwater diminished. Moderate fluxes from the field fertilized with urea continued over 6 days, but calculations showed that NH3 transfer from floodwater to atmosphere was retarded during the middle period of the experiment, particularly on day 2 when a thick algal scum appeared on the water surface. The results indicate that this algal mass obstructed the transport of NH3 across the water-air interface until the scum was dispersed by wind action. Nevertheless, the prolonged NH3 losses on the urea treatment were due primarily to high floodwater pH values promoted by the strong algal growth during the daylight hours. Nitrogen-15 balance studies showed that incorporation of fertilizer into drained soil substantially increased recoveries of fertilizer N in rice plants and soil compared with incorporation of fertilizer in the presence of standing floodwater. Ammonia loss measurements on these treatments when urea was applied suggested that the improvement in fertilizer N efficiency was due mainly to reductions in NH3 loss.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01049507
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  • 3
    Electronic Resource
    Electronic Resource
    Mineral nutrition of slash pine in subtropical australia. I. stand growth response to fertilization (1995)
    Springer
    Nutrient cycling in agroecosystems 41 (1995), S. 93-100 
    Details
    ISSN: 1573-0867
    Keywords: fertilization ; P application method ; P rate ; slash pine ; stand growth response
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Fertilization at plantation establishment and later age is often required to maximize stand growth of slash pine (Pinus elliottii) in subtropical Australia. A field experiment was conducted to examine stand growth response of slash pine in the first 11.5 years of plantation following (1) initial fertilization at plantation establishment with phosphorus (P) at 11, 22, 45 and 90 kg P ha−1 which were either banded or broadcast in the presence or absence of basal fertilizers containing 50 kg nitrogen (N) ha−1, 50 kg potassium (K) ha−1 and 5 kg copper (Cu) ha−1 and (2) additional application of 40 kg P ha−1 at age 10 years. The initial P fertilization significantly increased the stand growth in the first 9.6 years. The P banded application was more effective in improving the stand growth than the P broadcast application. Application of the N, K and Cu basal fertilizers did not affect the stand growth. Overall, 53–73% of the variation in basal area and volume growth in the first 9.6 years was explained by the initial P fertilization, indicating that P deficiency was the major factor limiting the stand growth under the experimental conditions. Optimum plantation age, at which the maximum periodical annual increment (PAI) of basal area was obtained, increased from age 10.9 to 12 years when the initial P rate increased from 11 to 90 kg P ha−1. Application of additional 40 kg P ha−1 at age 10 years resulted in a further improvement in the stand growth at age 11.5 years. With 66% of the variation in basal area PAI between ages 9.6 and 11.5 years, 50% was explained by the initial P fertilization and 16% by the additional P applied at age 10 years. Similarly, 51% and 12% of the variation in volume PAI were attributed to the initial P fertilization and the additional P application, respectively. This highlights the need of refertilization with P on some established stands of slash pine at later ages.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00750750
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  • 4
    Electronic Resource
    Electronic Resource
    Mineral nutrition of slash pine in subtropical Australia. II. foliar nutrient response to fertilization (1995)
    Springer
    Nutrient cycling in agroecosystems 41 (1995), S. 101-107 
    Details
    ISSN: 1573-0867
    Keywords: fertilization ; foliar nutrient concentration ; method of P application ; mineral nutrition ; P rate ; slash pine
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract In the previous paper, we reported the stand growth of slash pine (Pinus elliottii) during the first 11.5 years of plantation in response to (1) initial fertilization at plantation establishment with P rates of 11, 22, 45 and 90 kg P ha−1 which were either banded or broadcast in the presence or absence of basal fertilizers containing 50 kg N ha−1, 50 kg K ha−1 and 5 kg Cu ha−1 and (2) application of additional 40 kg P ha−1 at age 10 years. Here we present the responses in foliar nutrient concentrations of slash pine in the first 11.5 years to the initial fertilization and the additional P applied at age 10 years. Foliar N and K concentrations in the first 9.6 years of plantation decreased with the initial P rate. Application of the basal fertilizers improved foliar Cu concentration. Foliar Ca and Mg concentrations increased linearly with the initial P rate. The initial fertilization did not affect foliar Mn concentration in the first 9.6 years. Foliar P concentration increased quadratically with the initial P rate, which accounted for 77–86% of the variation in foliar P concentration. Most of the explained variation in foliar nutrient concentrations was attributable to the plantation age except for foliar P concentration. In the case of foliar P concentration, 53% was explained by the initial P rate, 31% by the plantation age and 2% by the positive interaction between the initial P rate and the plantation age. Foliar P concentration of slash pine at age 11.5 years increased quadratically with the initial P rate and linearly with the additional 40 kg P ha−1 applied at age 10 years, accounting for 81% of the variation in the foliar P concentration. Foliar nutrient analysis indicated that P was the major limiting nutrient affecting the stand growth of slash pine in the first 11.5 years.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00750751
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  • 5
    Electronic Resource
    Electronic Resource
    Mineral nutrition of slash pine in subtropical Australia. III. Relationships between foliar P concentration and stand growth (1995)
    Springer
    Nutrient cycling in agroecosystems 41 (1995), S. 109-115 
    Details
    ISSN: 1573-0867
    Keywords: foliar phosphorus ; plantation age ; slash pine ; stand growth
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Foliar P concentration of slash pine was significantly related to the stand growth in the first 11.5 years. The relationship between foliar P concentration and total stand growth at foliar sampling improved as the plantation aged with coefficient of determination (R2) increasing from 0.14–0.15 at age 3.3 years to 0.56–0.65 at age 9.6 years. However, only 12–18% of the variation in total stand growth was explained by foliar P concentration at age 11.5 years when additional 40 kg P ha−1 was applied to the stands at age 10 years. This suggests that caution should be exercised in interpreting the foliar P concentrations of the established stands which had received application of P fertilizer just prior to foliar sampling. Periodic stand growth was more closely related to the foliar P concentration than total stand growth. Basal area and volume periodic annual increment (PAI) was better related to the foliar P concentration than height PAI. Optimum foliar P concentration, at which the maximum stand growth was obtained, was between 0.093% and 0.110%. The optimum foliar P concentration for height PAI immediately prior to foliar sampling decreased from 0.097% at age 3.3 years to 0.070% at age 9.6 years. Critical foliar P concentration at age 9.6 years, at which 90% of the maximum basal area growth was obtained, was between 0.066% and 0.070%. Both optimum and critical foliar P concentration might decrease as the plantation aged.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00750752
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  • 6
    Electronic Resource
    Electronic Resource
    Quantification of L-tryptophan and L-kynurenine by liquid chromatography/electron capture negative ion chemical ionization mass spectrometry (1994)
    Chichester : Wiley-Blackwell
    Biological Mass Spectrometry 23 (1994), S. 27-32 
    Details
    ISSN: 1052-9306
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: In a number of infectious and inflammatory diseases, stimulation of the immune system can lead to increased accumulation of tryptophan metabolites via induction of kynurenine pathway enzymes in extrahepatic tissues. We developed a liquid chromatographic/mass spectrometric (LC/MS) method suitable for tracing the disposition of 13C isotopomers of L-tryptophan and L-kynurenine in various cultured cell, tissue slice, and whole animal model systems used to investigate tryptophan flux through the kynurenine pathway. The method employs extractive derivatization of the analytes and their 2H internal standards with pentafluorobenzyl bromide in order to enhance the negative ion chemical ionization (NICI) mass spectrometric response. Normal-phase liquid chromatographic separation of derivatized analytes was optimized using a silica column with organic solvents, followed by particle beam transfer and NICI-MS. Standard curves were linear over the range 1-250 ng per sample. Particle beam and mass spectrometric operating parameters were optimized with direct flow injections of 1-(methylamino) anthra-quinone, which is an ideal test compound for the evaluation of LC/NICI-MS. The developed method was used to quantify the conversion of (13C6)L-tryptophan to (13C6)L-kynurenine by human monocytes (THP-1) stimulated with interferon-γ, lung and brain tissue slices obtained from gerbils immune-stimulated with pokeweed mitogen. The effect of whole body immune stimulation on the plasma levels of engogenous L-kynurenine in mice stimulated with interferon-γ was also quantified.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bms.1200230106
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  • 7
    Electronic Resource
    Electronic Resource
    Novel fused silica capillary columns: Surface modification through controlled doping of the preform-tube (1988)
    Weinheim : Wiley-Blackwell
    Journal of High Resolution Chromatography 11 (1988), S. 395-400 
    Details
    ISSN: 0935-6304
    Keywords: Gas chromatography (GC) ; Fused silica ; Column technology ; Surface modification ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A method has been developed for fabricating fused silica capillary columns which have specific surface properties but still retain the excellent strength, flexibility, and resilience of pure fused silica. By using the Modified Chemical Vapor Deposition process (MCVD), typically used for the production of optical fiber lightguides, inorganic dopants such as Al, Nd, Ge, and P can be introduced into the preform-tube by MCVD. Doped columns have a wide range of specific surface properties, and columns with undoped fused silica prepared by MCVD are more chemically inert and less acidic than columns prepared by conventional methods. This paper describes the method for fabricating capillaries and the initial studies to characterize them.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jhrc.1240110507
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  • 8
    Electronic Resource
    Electronic Resource
    Electrochemical dissolution of metallic implants prior to histologic sectioning (1979)
    Hoboken, NJ : Wiley-Blackwell
    Journal of Biomedical Materials Research 13 (1979), S. 337-338 
    Details
    ISSN: 0021-9304
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine , Technology
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jbm.820130212
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  • 9
    Electronic Resource
    Electronic Resource
    Surface roughness modulates the local production of growth factors and cytokines by osteoblast-like MG-63 cells (1996)
    Hoboken, NJ : Wiley-Blackwell
    Journal of Biomedical Materials Research 32 (1996), S. 55-63 
    Details
    ISSN: 0021-9304
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine , Technology
    Notes: Titanium (Ti) surface roughness affects proliferation, differentiation, and matrix production of MG-63 osteoblast-like cells. Cytokines and growth factors produced in the milieu surrounding an implant may also be influenced by its surface, thereby modulating the healing process. This study examined the effect of surface roughness on the production of two factors known to have potent effects on bone, prostaglandin E2 (PGE2) and transforming growth factor β1 (TGF-β1). MG-63 cells were cultured on Ti disks of varying roughness. The surfaces were ranked from smoothest to roughest: electropolished (EP), pretreated with hydrofluoric acid-nitric acid (PT), fine sand-blasted, etched with HCl and H2SO4, and washed (EA), coarse sand-blasted, etched with HCl and H2SO4, and washed (CA), and Ti plasma-sprayed (TPS). Cells were cultured in 24-well polystyrene (plastic) dishes as controls and to determine when confluence was achieved. Media were collected and cell number determined 24 h postconfluence. PGE2 and TGF-β1 levels in the conditioned media were determined using commercial radioimmunoassay and enzyme-linked immunosorbent assay kits, respectively. There was an inverse relationship between cell number and Ti surface roughness. Total PGE2 content in the media of cultures grown on the three roughest surfaces (FA, CA, and TPS) was significantly increased 1.5-4.0 times over that found in media of cultures grown on plastic or smooth surfaces. When PGE2 production was expressed per cell number, CA and TPS cultures exhibited six- to eightfold increases compared to cultures on plastic and smooth surfaces. There was a direct relationship between TGF-β1 production and surface roughness, both in terms of total TGF-β1 per culture and when normalized for cell number. TGF-β1 production on rough surfaces (CA and TPS) was three to five times higher than on plastic. These studies indicate that substrate surface roughness affects cytokine and growth factor production by MG-63 cells, suggesting that surface roughness may modulate the activity of cells interacting with an implant, and thereby affect tissue healing and implant success. © 1996 John Wiley & Sons, Inc.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
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  • 10
    Electronic Resource
    Electronic Resource
    Effect of titanium surface roughness on chondrocyte proliferation, matrix production, and differentiation depends on the state of cell maturation (1996)
    Hoboken, NJ : Wiley-Blackwell
    Journal of Biomedical Materials Research 30 (1996), S. 145-155 
    Details
    ISSN: 0021-9304
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine , Technology
    Notes: Although it is well accepted that implant success is dependent on various surface properties, little is known about the effect of surface roughness on cell metabolism or differentiation, or whether the effects vary with the maturational state of the cells interacting with the implant. In the current study, we examined the effect of titanium (Ti) surface roughness on chondrocyte proliferation, differentiation, and matrix synthesis using cells derived from known stages of endochondral development. Chondrocytes derived from the resting zone (RCs) and growth zone (GCs) of rat costochondral cartilage were cultured on Ti disks that were prepared as follows: HF-HNO3-treated and washed (PT); PT-treated and electropolished (EP); fine sand-blasted, HCl-H2SO4-etched, and washed (FA); coarse sand-blasted, HCl-H2SO4-etched, and washed (CA); or Ti plasma-sprayed (TPS). Based on surface analysis, the Ti surfaces were ranked from smoothest to roughest: EP, PT, FA, CA, and TPS. Cell proliferation was assessed by cell number and [3H]-thymidine incorporation, and RNA synthesis was assessed by [3H]-uridine incorporation. Differentiation was determined by alkaline phosphatase specific activity (AL-Pase). Matrix production was measured by [3H]-proline incorporation into collagenase-digestible (CDP) and noncollagenase-digestible (NCP) protein and by [35S]-sulfate incorporation into proteoglycan. GCs required two trypsinizations for complete removal from the culture disks; the number of cells released by the first trypsinization was generally decreased with increasing surface roughness while that released by the second trypsinization was increased. In RC cultures, cell number was similarly decreased on the rougher surfaces; only minimal numbers of RCs were released by a second trypsinization. [3H]-thymidine incorporation by RCs decreased with increasing surface roughness while that by GCs was increased. [3H]-Uridine incorporation by both GCs and RCs was greater on rough surfaces. Conversely, ALPase in the cell layer and isolated cells of both cell types was significantly decreased. GC CDP and NCP production was significantly decreased on rough surfaces while CDP production by RC cells was significantly decreased on smooth surfaces. [35S]-sulfate incorporation by RCs and GCs was decreased on all surfaces compared to tissue culture plastic. The results of this study indicate that surface roughness affects chondrocyte proliferation, differentiation, and matrix synthesis, and that this regulation is cell maturation dependent. © 1996 John Wiley & Sons, Inc.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
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