物件導向軟體之架構(Object-Oriented Software Construction)探討

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American Society for Testing and Materials

Biogeochemistry of the Human Environment.- The Biosphere.- Soils.- Waters.- Air.- Plants.- Humans.- Biogeochemistry of Trace Elements.- Trace Elements of Group 1 (Previously Group Ia).- Trace Elements of Group 2 (Previously Group IIa).- Trace Elements of Group 3 (Previously Group IIIb).- Trace Elements of Group 4 (Previously Group IVb).- Trace Elements of Group 5 (Previously Group Vb).- Trace Elements of Group 6 (Previously Group VIb).- Trace Elements of Group 7 (Previously Group VIIb).- Trace Elements of Group 8 (Previously Part of Group VIII).- Trace Elements of Group 9 (Previously Part of Group VIII).- Trace Elements of Group 10 (Previously Part of Group VIII).- Trace Elements of Group 11 (Previously Group Ib).- Trace Elements of Group 12 (Previously Group IIb).- Trace Elements of Group 13 (Previously Group IIIa).- Trace Elements of Group 14 (Previously Group IVa).- Trace Elements of Group 15 (Previously Group Va).- Trace Elements of Group 16 (Previously Group VIa).- Trace Elements of Group 17 (Previously Group VIIa).

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Trace Elements From Soil to Human

Polycyclic Hydrocarbons Vol. 1. Pp. xxvi + 487. 126S. (With a chapter on carcinogenesis by Regina Schoental.) Vol. 2. Pp. lvii + 487. 140s. By E. Clar. (London and New York: Academic Press; Berlin: Springer-Verlag, 1964.)

Polycyclic Aromatic Hydrocarbons

Summary: The discovery of novel small-molecule antibacterial drugs has been stalled for many years. The purpose of this review is to underscore and illustrate those scientific problems unique to the discovery and optimization of novel antibacterial agents that have adversely affected the output of the effort. The major challenges fall into two areas: (i) proper target selection, particularly the necessity of pursuing molecular targets that are not prone to rapid resistance development, and (ii) improvement of chemical libraries to overcome limitations of diversity, especially that which is necessary to overcome barriers to bacterial entry and proclivity to be effluxed, especially in Gram-negative organisms. Failure to address these problems has led to a great deal of misdirected effort.

Challenges of Antibacterial Discovery

A differential mass-balance equation for the uptake of organic chemicals into the aerial plant compartment from soil and air is derived. Processes considered are uptake from soil, gaseous deposition, volatilization from leaves, transformation and degradation, and growth. An analytical solution is developed. Chemical data needed are K Ow , K AW , and reaction rate constants. Constant average values for environmental parameters are assumed. Plant properties are typical for grass and green fodder. Calculations for 2,3,7,8-TCDD, and the comparison to a recently tested numerical four-compartment model shows the applicability of the mass-balance approach. The equation could be incorporated into existing multimedia and soil transport models and may be useful for the hazard assessment of contaminated soils.

Generic one-compartment model for uptake of organic chemicals by foliar vegetation.

Background. Models for predicting uptake and transport of chemicals in plants are applied in pesticide design, risk assessment, and environmental biotechnology. Objective. This review considers the theoretical basics of the most popular models, and discusses what they have in common. The line is drawn between models for neutral compounds, and models for weak and strong electrolytes. Main Features: Neutral Compounds. Neutral compounds undergo only very few processes inside plants (lipophilic interactions, metabolism), in contrast to weak electrolytes. The models developed for neutral compounds are widely applied in the risk assessment of environmental contaminants, but are not of much use for weak electrolytes, such as pesticides. Weak electrolytes. A very important process for weak electrolytes is the 'ion trap', which traps chemicals that dissociate inside plant cells. This is considered in the popular models of Kleier, Satchivi and Briggs. Other relevant processes for electrolytes are electrophilic interactions, speciation and complex formation. None of the currently used models considers these processes. Conclusions. The accuracy of models for neutral compounds is satisfactory, but the prediction of electrolyte behavior inside plants is still quite difficult due to gaps in knowledge.

Plant uptake and transport models for neutral and ionic chemicals

A study on uptake of neutral and dissociating organic compounds from soil solution into roots, and their subsequent translocation, was undertaken using model simulations. The model approach combines the processes of lipophilic sorption, electrochemical interactions, ion trap, advection in xylem and dilution by growth. It needs as input data, apart from plant properties, log KOW, pKa and the valency number of the compound, and pH and chemical concentration in the soil solution. Equilibrium and dynamic (steady-state) models were tested against measured data from several authors, including non-electrolytes as well as weakly acidic and weakly basic compounds. Deviations from the measured values led to further development of the model approach: sorption in the central cylinder may explain the small transpiration stream concentration factor of lipophilic compounds. For non-electrolytes, the model predicted uptake and translocation with high accuracy. For acids and bases, the tendency of the results was satisfactory. The dynamic model and the equilibrium approach gave similar results for the root concentration factor. The calculation of the transpiration stream concentration factor was more accurate with the dynamic model, but still gave deviations up to factor of ten or more. The dominating process for monovalent weak electrolytes was found to be the ion trap effect.



© 2000 Society of Chemical Industry

Modelling uptake into roots and subsequent translocation of neutral and ionisable organic compounds

Introduction / Stefan Trapp and J. Craig Mc Farlane --Anatomy and physiology of plant conductive systems / J. Craig Mc Farlane -- Principles governing uptake and transport of chemicals / Richard H. Bromilow and Keith Chamberlain -- Metabolic processes for organic chemicals in plants / Dieter Komossa, Christian Langebartels, and Heinrich Sandermann, Jr. -- Model for uptake of xenobiotics into plants / Stefan Trapp -- Partitioning and transport of organic chemicals between the atmopsheric environment and leaves / Markus Riederer -- Interpreting chemical partitioning in soil-plant-air systems with a fugacity model / Sally Paterson and Donald Mackay -- Dynamics of leaching, uptake, and translocation : the Simulation Model Network Atmosphere-Plant-Soil (SNAPS) / Michael Matthies and Herwart Behrendt.

Stefan Trapp

Papers

Generic one-compartment model for uptake of organic chemicals by foliar vegetation.

Plant uptake and transport models for neutral and ionic chemicals

Modelling uptake into roots and subsequent translocation of neutral and ionisable organic compounds

Plant contamination: modeling and simulation of organic chemical processes.

Modeling the bioconcentration of organic chemicals in plants.