Dear Sir: In a recent article, Finkelstein (1976) has shown that the measured water permeabil i ty th rough a leci thin-decane planar bilayer m em b ran e is similar to the calculated permeabili ty t h rou g h a sheet o f n h e x a d e c a n e 50 ,~ thick. Th a t is, the measured water permeabil i ty, Pa, was found equal to DKhc/AX, where D is the diffusion constant o f water in water, Khe is t...

Recent evidence indicates that ionic selectivity in voltage-gated Na 1 channels is mediated by a small number of residues in P-region segments that link transmembrane elements S5 and S6 in each of four homologous domains denoted I, II, III, and IV. Important determinants for this function appear to be a set of conserved charged residues in the first three homologous domains, Asp(I), Glu(II), an...

The aquaporins (AQPs) are a family of intrinsic membrane proteins that function as water-selective channels in the plasma membranes of the cells of many watertransporting tissues (1, 2). The first AQP to be identified, CHIP28 (later called AQP-CHIP), was purified by Agre and his colleagues from human erythrocytes in the late 1980s and its cDNA sequence was reported in 1991 (reviewed in ref. 2)....

A passive diffusion model has been developed which simultaneously accounts for the dependence of phloem mobility on permeability and acid dissociation. The model is consistent with the observation that the addition of an acid moiety to an otherwise phloem immobile compound may enhance that compound's ability to move in the phloem. However, acid trapping in the basic phloem is not the only enhan...

•Consensus machine learning models perform better than singular models•Quality-oriented data selection yields results using all data•The uncertainty of test determines the theoretical limit a model's performance•The concepts actual and observed performances solubility are introduced Accurate prediction chemical substances in solvents remains challenge. The sparsity high-quality is recognized as...