scholarly journals Unit of Volumetric Electrical Charge Density

2020 ◽  
Author(s):  
Nature ◽  
1963 ◽  
Vol 200 (4907) ◽  
pp. 691-692 ◽  
Author(s):  
P. S. VASSAR ◽  
H. E. TAYLOR ◽  
C. F. A. CULLING

2019 ◽  
Vol 25 (S2) ◽  
pp. 44-45
Author(s):  
E. Voelkl ◽  
F. Zheng ◽  
V. Migunov ◽  
M. Beleggia ◽  
R.E. Dunin-Borkowski

2013 ◽  
Vol 304 (6) ◽  
pp. F781-F787 ◽  
Author(s):  
Carl M. Öberg ◽  
Bengt Rippe

In the current study we explore the electrostatic interactions on the transport of anionic Ficoll (aFicoll) vs. neutral Ficoll (nFicoll) over the glomerular filtration barrier (GFB) modeled as a charged fiber matrix. We first analyze experimental sieving data for the rat glomerulus, and second, we explore some of the basic implications of a theoretical model for the electrostatic interactions between a charged solute and a charged fiber-matrix barrier. To explain the measured difference in glomerular transport between nFicoll and aFicoll (Axelsson J, Sverrisson K, Rippe A, Fissell W, Rippe B. Am J Physiol 301: F708–F712, 2011), the present simulations demonstrate that the surface charge density needed on a charged fiber matrix must lie between −0.005 C/m2 and −0.019 C/m2, depending on the surface charge density of the solute. This is in good agreement with known surface charge densities for many proteins in the body. In conclusion, the current results suggest that electrical charge makes a moderate contribution to glomerular permeability, while molecular size and conformation seem to be more important. Yet, the weak electrical charge obtained in this study can be predicted to nearly totally exclude albumin from permeating through “high-selectivity” pathways in a charged-fiber matrix of the GFB.


2008 ◽  
Vol 2 (2) ◽  
Author(s):  
Mahrokh Dadsetan ◽  
Andrew M. Knight ◽  
Catalina Vallejo ◽  
Lichun Lu ◽  
Anthony J. Windebank ◽  
...  

Natural and synthetic hydrogels have attracted much attention for nerve regeneration. Previous studies have shown that electrical charge has significant effect on stimulation of neurite outgrowth. In this work, incorporation of a positively charged monomer into the photocrosslinkable oligo(polyethylene glycol) fumarate (OPF) hydrogel has been investigated. We have evaluated the effect of localized positive charge on neurite outgrowth in culture with an objective that positively charged hydrogels ultimately can be used for stimulating in vivo nerve regeneration. The effect of charged modification has been also studied on mechanical properties and swelling ratio of these hydrogels. Our data indicated that with increasing charge density hydrogels swelling ratio increased in water, however it remained constant in PBS. We also demonstrated that compressive modulus and tensile strength of the hydrogels improved with incorporation of electrical charge into the hydrogels. Biodegradation of modified hydrogels was investigated in a series of biomimetic solutions. OPF hydrogels appeared to be more susceptible to oxidative degradation as opposed to the hydrolytic degradation in enzymes and acidic solution, and the degradation rate was correlated to the PEG molecular weight and charge density of the hydrogels. To investigate the effect of charge modification on nerve cell attachment and differentiation, dissociated dorsal root ganglion (DRG) cells were plated onto the modified and unmodified hydrogels surfaces. DRG cells attached and extended their neurites more readily on the surface of positively charged hydrogels as opposed to the unmodified hydrogels.


Author(s):  
S. Ritchie ◽  
J. C. Bennett ◽  
A. Prodan ◽  
F.W. Boswell ◽  
J.M. Corbett

A continuous sequence of compounds having composition NbxTa1-xTe4; 0 ≤ x ≤ 1 have been studied by electron diffraction and microscopy. Previous studies have shown that the end members of the series, TaTε4 and NbTε4 possess a quasi-one-dimensional character and exhibit charge density wave (CDW) distortions. In these compounds, the subcell structure is tetragonal with axes (a × a × c) and consists of the metal atoms (Nb or Ta) centered within an extended antiprismatic cage of Te atoms. At room temperature, TaTε4 has a commensurate modulation structure with a 2a × 2a × 3c unit cell. In NbTε4, an incommensurate modulation with × ∼ 16c axes is observed. Preliminary studies of the mixed compounds NbxTα1-xTε4 showed a discontinuous jump of the modulation wave vector commensurate to incommensurate when the Nb dopant concentration x, exceeded x ≃ 0.3, In this paper, the nature of the compositional dependence of is studied in greater detail and evidence is presented for a stepwise variation of . This constitutes the first direct evidence for a Devil's staircase in CDW materials.


1995 ◽  
Vol 5 (5) ◽  
pp. 539-545 ◽  
Author(s):  
J. Dumas ◽  
N. Thirion ◽  
M. Almeida ◽  
E. B. Lopes ◽  
M. J. Matos ◽  
...  

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