Uptake efficiency

Increased biomagnification of higher chlorinated congeners because increasing hydrophobicity decreased elimination rates but not uptake efficiency... 

In crustaceans, Corg/Csed ratios decreased with decreasing hydrophobicity the opposite occurred in eels and is attributed to differences in uptake efficiencies and low elimination rates of lower-chlorinated congeners in crustaceans (van der Oost et al. 1988). 

Fed diets containing 6-150 mg PCB 133 or PCB 197/kg diet for 191-247 days, or 550-1400 mg/kg diet for 65 days At 6-150 mg/kg diet, uptake efficiency was near 50% at higher dietary loadings, uptake efficiency decreased to 25%. No deaths in controls or at low dietary dosages 13-25% mortality at 550-1400 mg/kg diet. Prior to death, guppies were sluggish, uncoordinated, and darkly colored fish that died during exposure contained >0.7 pmol PCB/g FW 7... 

Fed PCB 133 at 550 mg/kg diet FW or PCB 197 at 530 mg/kg diet FW for 65 days, followed by a clean diet for 89 days, then reexposure to the contaminated diet for another 37 days No PCB clearance during initial exposure significant elimination of both PCBs when fed a clean diet. During reexposure, uptake efficiency for both PCBs was significantly higher than during the initial exposure 8... 

Opperhuizen, A. and S.M. Schrap. 1988. Uptake efficiencies of two polychlorobiphenyls in fish after dietary exposure to five different concentrations. Chemosphere 17 253-262. 

Trehan, S. R, Sharma, R. C. (2003). External phosphorus requirement of different potato Solanum tuberosum) cultivars resulting from different internal requirements and uptake efficiencies. Indian J. Agric. Set, 73, 54-56. 

The net uptake efficiency is measured in terms of the difference of the adsorption and desorption rate ... 

The brain uptake efficiency and distribution of the above compounds as well as D2 receptor affinities of derivatives of spiperone containing aliphatic halogens have been studied also330. 

Matsumoto T, Numata M, Anada T et al (2004) Chemically modified polysaccharide schizophyllan for antisense oligonucleotides delivery to enhance the cellular uptake efficiency. Biochem Biophys Acta 1670 91-104... 

A summary and discussion of empirical data on relationships between cationic lipid molecular structure and transfection activity are provided by Koynova and Tenchov Structural features of cationic lipids are related to their interaction with biomembranes and the uptake efficiency of transfection complexes. 

Dietary Uptake Efficiency or Chemical Assimilation Efficiency... 

A high molecular weight or large molecular size often is offered as an explanation for the apparently low bioavailability or uptake efficiency of extremely hydrophobic organic chemicals (McKim et al., 1985 Anliker and Moser, 1987 Bruggeman et al., 1984 Niimi and Oliver, 1987). The rationale is that membrane diffusion coefficients drop with increasing weight. 

Gill uptake efficiencies. Gill uptake efficiencies of a range of hydrophobic organic chemicals in rainbow trout (data from McKim et al. (1985)) as a function of the chemical s Kow. The solid line represents the fish gill ventilation model predictions of Gobas and Mackay (1987). 

While both individual exposure to lead and the uptake efficiencies of individuals are very variable, it is evident that exposure arises from a number of sources and control or human lead intake, if deemed to be desirable, requires attention to all of those sources. An additional pathway of exposure, not easily quantified, and not included above is ingestion of lead-rich surface dust by hand-to-mouth activity in young children. 

Jones, M. D., Durall, D. M. Tinker, P. B. (1998). A comparison of arbuscular and ectomycorrhizal Eucalyptus coccifera growth response, phosphorus uptake efficiency and external hyphal production. New Phytologist, 140, 125-34. 

Either, in reducing soils with mobile Mn, the uptake efficiencies (BCF values) must be identical, corresponding to a certain Ej (L) jj of about -0.07 V (V.vitis-idaea, various limnetic plants) or... 

Knax is the maximum uptake rate, is the half-saturaion constant, and a is the uptake efficiency at low nutrient levels... 

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