Nutritional genomics has reached the public through applications of the Human Genome Project offered direct to consumers (DTC). The ability to pursue nutrigenetic testing without the involvement of a health care professional has received considerable attention from academic and policy commentators. To better understand the knowledge and attitudes of Canadian health care professionals regarding nutritional genomics and nutrigenetic testing, qualitative research in the form of focus group discussions was undertaken. Four key themes emerged: (1) concerns over DTC testing; (2) lack of health care professional competency; (3) genetic scepticism and inevitability; (4) expectation of regulation. Together, they indicate that health care professionals have little knowledge about nutritional genomics and hold contradictory attitudes towards genomics in general, and to nutritional genomics in particular. Respondents argue in favour of a delivery model where health care professionals act as intermediaries. They are also aware of their lack of competency to provide such services. To ensure greater public protection, respondents cite the importance of more stringent regulatory oversight of DTC genetic testing. Whether such an approach is necessary to address the various ethical and social issues raised by nutrigenetic testing remains an open debate.

We have synthesized a series of [Mg 2+ (1-x) M 3+ x (OH) 2 ][TA 2-(x/2) ]‚zH 2 O (M 3+) Ga 3+ or Al 3+ and TA ) C 6 H 4 (COO -) 2 ) from mixed-metal chloride solutions with initial M 3+ mole fractions of 0.20, 0.25, and 0.33, at constant pH values of 6.8, 7.7, 8.6, and 10.0. Terephthalatecontaining products were obtained only under conditions that resulted in a Mg:M 3+ ratio of 2:1 in the mixed metal hydroxide layers, indicating that a high layer charge density is necessary to incorporate terephthalate anions between the inorganic layers. Anion-exchange reactions were subsequently performed to produce LDHs intercalated with PW 11 O 39 7and H 2 W 12 O 40 6anions, yielding products that displayed sharp powder diffraction patterns. In each case, the surface area of the POM-intercalated product was found to be approximately 40-45 m 2 /g, indicating that the micropore system is totally blocked and that the materials are virtually nonporous; this may result from the high layer charge density of the LDHterephthalate precursors.

The assignment of the 29Si CP/MAS-NMR spectrum of naturally-occurring sepiolite clay was re-examined using 29Si COSY and 1H-29Si HETCOR pulse sequences. Each of the three main resonances at −92.1, −94.6 and −98.4 ppm has been attributed to one of the three pairs of equivalent Si nuclei in the basal plane, and the resonance at −85 ppm to Q2(Si-OH) Si nuclei. On the basis of the COSY experiment, the resonance at −92.1 ppm is unambiguously assigned to the intermediate, near-edge Si sites. The HETCOR experiment revealed that the resonance at −94.6 ppm cross-polarizes almost entirely from the Mg-OH protons, and therefore is assigned to the central Si position. The remaining resonance at −98.4 ppm correlates strongly to the protons of the structural water molecules and therefore is assigned to the edge Si sites. Nearly complete rehydration was achieved at room temperature by exposing sepiolite samples that had been partially dehydrated at 120°C to water vapor or to D2O vapor. The rehydration results support the 29Si NMR peak assignments that were made on the basis of the COSY and HETCOR experiments.The 29Si CP/MAS-NMR spectrum corresponding to the folded sepiolite structure in which approximately one half of the structural water has been removed by heating to 350°C is reported for the first time. The chemical shift values and relative intensities are significantly different compared to the resonances that are observed in the corresponding spectrum of the true sepiolite anhydride. These observations support the earlier claim that sepiolite heated to ∼350°C exists as a distinct phase to be differentiated from that of the completely dehydrated state.

We report the synthesis of acidic (Zn/Al-POM) and basic (Mg/Al-POM and Mg/Ga-POM) materials by a general route previously demonstrated only for basic LDH materials. In each case, H(2)W(12)O(40)(6)(-) or PW(11)O(39)(7)(-) pillared materials with significant BET surface areas were obtained. Stringent control over the M(2+):M(3+) ratio in the layers of the POM-pillared products was not possible, and loss of M(2+) was found to be the most severe for the Mg/Ga and Zn/Al materials. Infrared analysis indicated that complete exchange of adipate anions in the precursor material by POM anions was achieved except for the Zn/Al analogues. Removal of the residual adipate anions after washing the product with a dilute base solution was possible, but a concomitant decrease in surface area could not be avoided.

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