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. 2007 Aug 29;4:7. doi: 10.1186/1743-8977-4-7

Table 2.

Analysis of TiO2-nanoparticle distribution 24 h after exposure.

Compartment NO P NE RDI Χ2 Fraction of total Χ2
Air 348 2052 363 0.96 0.59 0.039
Epi/Endo 17 131 23 0.73 1.63 0.109
CT 11 54 10 1.15 0.22 0.015
Caplum 49 168 30 1.65 12.56 0.837
Total 425 2405 425 15.01

Note. The calculation of the data is described in the Methods section and an illustrating example is provided in the note to table 1. With three degrees of freedom (2-1 groups × 4-1 compartments) and a total chi-squared value of 15.01, the null-hypothesis of random distribution has to be rejected (p < 0.01). The capillary lumen has an RDI of 1.65 and a partial chi-squared value that contributes about 84% of the total chi-squared. It is the only compartment that meets both criteria for a preferential deposition. Abbreviations: Air: Air space; Epi/Endo: Epithelial/endothelial cells; CT: Connective tissue; Caplum: Capillary lumen. Χ2: Chi-squared test values. NO: Observed number of particles. NE: Expected number of particles. RDI: Relative deposition index.