Finite cells

This derivation makes a number of assumptions. Firstly, we assume that there is no disruption to the laminar flow pattern due to a finite disc surface, finite cell size, or eccentricity in disc rotation. To what extent design factors affect measured currents will be discussed further in the section on electrode construction. It is sufficient at this point to say that the criteria for negligible disruption can be met. 

To obtain the radial distribution of fluorescence intensity, Schwartz and Johnston [82] integrated eqn. (17) from v = 0 to v = This function, /(p), is important for the interpretation of quantum yield experiments in a finite cell. Sackett and Yardley [83] found it more instructive in interpreting time resolved experiments to transform from velocity dependence to time dependence [v = p/t, dv = (— p/t2 )df]. Their expression for photons emitted per unit radius is... 

Let us divide the T-space somehow into very small, but finite cells Q Gi, Q , , Qx, , which might be, for instance, cubes of equal size. The average value which the fine-grained density p(q, p, <) has at time t over the cell Six we will call coarse-grained density P (t) (read capital p) of this cell. Because of Eq. (54) we have... 

The influx Rs of cells from the pluripotent stem cell population to the committed stem cell fines is assumed mainly regulated by long-range humoral mechanisms 4>(e), implicating the cytokine G-CSF, c (/,). An intrinsic property of the hemopoietic chain is the presence of a time delay t° that arises because of finite cell maturation times and cell replication times for the neutrophil myelocytes, s (t). In fact, it is important to remember that once a cell from the pluripotent stem cell population is committed to the neutrophil lineage, it undergoes a series of nuclear divisions and enters a maturational phase for a period of time (t° 5-7 d) before release into circulation. The production function Rs has not only to be amplified, but... 

The size of a cell bank is dependent upon the scale of operation, frequency of use and replicative capacity of the cell line in question. Typically, an MCB might contain 20-50 ampoules and a WCB 100-200 ampoules. Larger banks may be prepared for stable continuous cell lines and this is a major advantage of this type of cell line in comparison with finite cell lines of limited replicative capacity. 

Finite cell culture A culture that is capable of only a limited number of population doublings after which the culture ceases proliferation. See also In vitro senescence . 

Immortalization The attainment by a finite cell culture, whether by perturbation or intrinsically, of the attributes of a continuous cell line. An immortalized cell is not necessarily one that is neoplastically or malignantly transformed. 

In vitro senescencei In vertebrate cell cultures, the property attributable to finite cell cultures namely, their inability to grow beyond a finite number of population doublings. Neither invertebrate nor plant cell cultures exhibit this property. 

Ci3 and K24 should be taken into account. In such cases, boundary conditions may become non-local in the sense that, for a finite cell thickness d and potential W, a situation at a boundary zj influences the conditions at the opposite boundary zz-... 

Let there exist exactly one critical point of index A in a fibre / [a, 6] = Qb Qa-Then the manifold Qt is homotopy equivalent to the finite cell complex obtained from the manifold Qa by gluing one cell cr of dimension to the boundary fa = dQa-The direct product of two indices x is called a handle of dimension... 

In cases 1-3 a conventional Warburg impedance cannot arise, as discussed earlier. However, there are certain situations where the equivalent circuit of figure 11 (except for the effects of finite cell thickness) would be appropriate. These include ... 

Immortalization The attainment by a finite cell culture of the attributes of a continuous cell line. 

Finite cell lines Cells derived from normal tissue via a primary culture which can replicate and undergo limited subculture until they become senescent (e.g., Wl-38, MRC-5) or immortalized (by chemical carcinogens, transforming viruses, hybridization, or genetic engineering). 

Finite cell lines have been extensively used in vaccine production but they are limited in cell type (usually... 

Generally, impedance measurements in low-temperature fuel cells are performed at finite cell current. This provides information on electrode performance at practically relevant currents. At high currents, the concentration polarization and the potential loss resulting from proton transport in the electrode could be significant and, hence, the realistic impedance model of the CCL should take these processes into account. 

Capillary method Unsteady out of finite cell Small Easy Average Concentration vs. time usually requires radioactive counter Good, but commonly used only with radioactive tracers... 

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