Lucas cells

Airborne Rn collected in a scintillator-coated Lucas cell is placed on a photomultiplier tube in the laboratory and counted (see discussion for Ra analysis by radon measurement in Section 6.4.1). Radon collected on a charcoal cartridge or other sorbent is measured by gamma-ray spectral analysis. In both cases, a 4-h period of ingrowth is needed to accumulate the radon progeny that contribute to the count rate. 

Lucas cell A cylindrical container for measuring radon gas that has a quartz window for transmitting scintillations at one end, has all other internal walls coated with ZnS(Ag) powder that responds with scintillations to alpha particles, and has a stopcock for connection to a pump to create a vacuum and then admitting a gas sample. 

This method involves filling a container with an air sample of radon and transferring it to a laboratory for analysis. One of the most useful devices is the scintillation flask, known as the Lucas cell. This consists of a chamber whose walls are coated with a scintillating material such as silver-activated zinc sulfide. The cell is optically coupled to a photomultiplier tube to count the light pulses (scintillation) induced by the a-particles interacting with the zinc sulfide coating. The scintillation flask can be filled either by evacuation or by airflow using a... 

The measurement of the radon content of water is based on extraction processes that exploit the high partition coefficient of radon either between gas and water or between organic liquid scintillators and water. In particular, by introducing fine gas bubbles to water, it is possible to extract radon very efficiently. Radon is thus bubbled out from water and collected in a Lucas cell. The detection limit for this method is very low, 50Bqm . ... 

The scintillation or Lucas cell (Lucas, 1957) is made by coating the inside of a Plexiglass, quartz or metal cell with silver-activated zinc sulphide (ZnS[Ag]). After transferring the Rn to the cell, it is stored for 1-2 h to allow Rn daughters, Po, Pb, and Po to equilibrate partially. Alpha decays from Rn, Po and Po cause emissions of photons from the ZnS[Ag]. These are converted into electrical signals using a photomultiplier tube (PMT) attached to the cell and routed to a counter. 

R. J. Ring and D. Roysten, A Review of Fluorine Cells and Fluorine Production Facilities AAEC/E281, Australian Atomic Energy Commission Research Establishment, Lucas Heights, Australia, 1973. 

Lucas AD, Bursill C, Guzik TJ, Sadowski J, Channon KM, Greaves DR. Smooth muscle cells in human atherosclerotic plaques express the fractalkine receptor CX3CR1 and undergo chemotaxis to the CX3C chemokine fractalkine (CX3CL1). Circulation 2003 108(20) 2498-2504. 

Lucas AD, Chadwick N, Warren BF, et al. The transmembrane form of the CX3CL1 chemokine fractalkine is expressed predominantly by epithelial cells in vivo. Am J Pathol 2001 158 855-866. 

Draetta, G., Luca, F., Westendorf, J., Brizuela, L., Ruderman, J., and Beach, D. (1989). cdc2 protein kinase is complexed with both cyclin A and B evidence for proteolytic inactivation of MPF. Cell 56 829-836. 

Mezzit LA, Lucas WJ 1996 Plasmodesmatal cell transport of proteins and nucleic acids. Plant Mol Biol 32 251-273... 

Blonder, J., Rodriguez-Galan, M.C., Chan, K.C., Lucas, D.A., Yu, L.R., Conrads, T.P, Issaq, H. J., Young, H.A., Veenstra, T.D. (2004). Analysis of murine natural killer cell microsomal proteins using two-dimensional liquid chromatography coupled to tandem electrospray ionization mass spectrometry. J. Proteome Res. 3, 862-870. 

We see some similarities between the major life processes in plants (growth and differentiation) and the major life processes in animals and humans (proliferation and differentiation). We expect in future to relate this concept to animal production and to human health, to be able to cross the bridge from soil to plant to animal and finally human health. For example, the development in medicine of differentiation therapy in which vitamin A-derivates are used to treat human cancer cells in vitro (De Luca el al., 1995). Cancer is defined by too much uncontrolled growth of cells without enough differentiation. Using treatment with vitamin A-derivatives - a product of differentiation processes in the plant - undifferentiated cancer cells change into differentiated more healthy ones. 

Lucas WJ, Wolf, S. Plasmodesmata the intracellular organelles of green plants. Trends Cell Biol 1993 3 308-315. 

Pesacreta TC, Lucas WJ. Plasma membrane coat and a coated vesicle-associated reticulum of membranes Their structure and possible interrelationship in Chara corallina. J Cell Biol 1984 98 1537-1545. 

Byrd, J., Kitada, S., Flinn, L, Aron, J., Pearson, M., Lucas, D., and Reed, J.C., The mechanism of tumor cell clearance by rituximab leukemia evidence of caspase activation and apoptosis induction. Blood, 99, 1038-1043, 2002. 

Koller-Lucae SM, Schott H, Schwendener RA. Low density lipoprotein and liposome mediated uptake and cytotoxic effect of N -octadecyl-l-P-o-arabino-furanosylcytosine (NOAC) in Daudi lymphoma cells. Br J Cancer 1999 80 1542. 

Kajaste-Rudnitski, A., Mashimo, T., ErenMel, M. P., Guenet, J. L., Lucas, M., and Despres, P. (2006) The 2, 5"-oligoadenylate synthetase lb is a potent inhibitor of West Nile virus replication inside infected cells. J. Biol.Chem. 281, 4624-4637. 

Sudakin, V., Ganoth, D., Dahan, A., Heller, H., Hershko, J., Luca, F.C., Ruderman, J.V. and Hershko, A. (1995). The cyclosome, a large complex containing cyclin-selective ubiquitin ligase activity, targets cyclins for destruction at the end of mitosis. Mol. Biol. Cell 6, 185-198. 

Sanchez V, Lucas M, Sanz A, Goberna R (1992) Decreased protein kinase C activity is associated with programmed cell death (apoptosis) in freshly isolated rat hepato-cytes. Biosci Rep 12 199-206... 

Sandiez-Margalet V, Lucas M, Solano F, Goberna R (1993) Sensitivity of insulin-secreting RIN m5F cells to undergoing apoptosis by the protein kinase C inhibitor staurosporine. Exp Cell Res 209 160-163... 

Rodriguez-Jimenez FJ, Moreno-Manzano V, Lucas-Dominguez R et al (2008) Hypoxia causes downregulation of mismatch repair system and genomic instabUity in stem cells. Stem CeUs 26 2052-2062... 

McDowell, E. M., Ben, T., Coleman, B., Chang, S., Newkirk, C., and De Luca, L. M. (1987a). Effects of retinoic acid on the growth and morphology of hamster tracheal epithelial cells in primary culture. Virchows Arch. B Cell Pathol. Inch Mol. Pathol. 54,38-51. 

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