Regenerative cells

Larson et al. (1996) investigated the ability of intermediate exposure to chloroform vapors to produce toxicity and regenerative cell proliferation in the nasal passage of male and female B6C3Fi mice. Groups of 8 animals of each sex were exposed to 0, 0.3, 2, 10, 30, or 90 ppm chloroform via inhalation for 6 hours a day, 7 days a week for 3, 6, or 13 weeks additional groups of 8 animals of each sex were exposed for... 

Larson and coworkers (1996) investigated the ability of intermediate-duration chloroform vapor exposure to produce toxicity and regenerative cell proliferation in the liver of male and female B6C3F, mice. 

In an earlier study, Larson et al. (1994c) examined the ability of chloroform vapors to produce toxicity and regenerative cell proliferation in the liver and kidneys of female B6C3F, mice and male Fischer 344 rats, respectively. Groups of 5 animals were exposed to 0, 1, 3, 10, 30, 100, or 300 ppm chloroform via inhalation for 6 hours a day for 7 consecutive days. Actual exposure concentrations measured for mice were 0, 1.2, 3, 10, 29.5, 101, and 288 ppm and for rats were 0, 1.5, 3.1, 10.4, 29.3, 100, and 271 ppm. Necropsies were performed on day 8. The kidneys of mice were affected only at the 300 ppm exposure, with approximately half of the proximal tubules lined by regenerating epithelium and an increased LI of tubule cells of 8-fold over controls. In the kidneys of male rats exposed to 300 ppm, about 25-50% of the proximal tubules were lined by regenerating epithelium. The LI for tubule cells in the cortex was increased at 30 ppm and above. 

In another study by Larson et al. (1994d) the possible relationships among chloroform-induced cytolethality, regenerative cell proliferation, and tumor induction were identified in male B6C3Fi mice dosed with chloroform by gavage in com oil. Mice received chloroform at doses of 0, 34, 90, 138, or 277 mg/kg/day for 5 days a week for 3 weeks. To monitor cell proliferation, mice were administered BrdU... 

Larson JE, Wolf DC, Butterworth BE. 1995a. Induced regenerative cell proliferation in livers and kidneys of male F-344 rats given chloroform in com oil by gavage or ad libitum in drinking water. Toxicology 95 73-86. 

The maximum open-circuit photo voltage, attainable in a dye-sensitized solar cell, is the difference between the Fermi level of the solid under illumination and the Nemst potential of the redox mediator. However, for these devices this limitation has not been achieved and Voc is in general much smaller. It appears that Voc is kinetically limited and the diode Equation 17.12 can be applied for an n-type semiconductor in a regenerative cell.23... 

In principle, photoelectrochemical cells can be used for the conversion of solar energy into electrical energy or for the production of a storable fuel. The first type (regenerative cells) consists of a semiconductor and inert counter electrode and a redox system in the electrolyte. The current-voltage behaviour is described by the diode equation, which is also valid for pure solid state devices (pn-junction, Schottky diode) i.e. 

Figure 1. Schematic representation of regenerative and photo-electrosynthetic cells. S is the sensitizer excited state, D is an electron donor, and D is the oxidized electron donor. Regenerative cells convert light into electricity while photoelectrosynthetic cells convert light into electricity and also produce chemical products.

Maximum energy conversion efficiencies of (/ lax = 0.1086 have recently been measured and verified for dye-sensitized regenerative cells illuminated with air mass 1.5 simulated solar irradiation [27]. The efficiency of photoelectrosynthetic cells must also include contributions from the free energy stored in the chemical products of the reduction and oxidation reactions. 

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