Novel columnar liquid crystalline compounds N,N'-bis(3,4,5-trialkoxylphenyl)ureas 1a-c (R = n-C(8)H(17), n-C(12)H(25), and n-C(16)H(33)) were synthesized, and their phase transitions were measured by differential scanning calorimetery. The superstructures were investigated by X-ray diffraction, polarized light optical microscopy, and IR spectroscopy. The compounds exhibited both rectangular and hexagonal columnar phases in which the urea molecules in each column were stacked in one direction with strong hydrogen bonds. To confirm the ferroelectric switching, optoelectronic experiments were carried out, and the hexagonal columnar phases of 1b and 1c gave a sharp peak of spontaneous polarization in response to an applied triangular wave electric field (0.1-18 Hz). This is the first example of ferroelectrically switchable columnar liquid crystal phases generated by achiral molecules.

The strain-promoted "double-click" (SPDC) reaction using Sondheimer diyne, a novel convergent method conjugating three molecules spontaneously, has enabled us to readily modify an azido-biomolecule with a small reporter azido-molecule.

The agravitropic nature of root growth of an auxin-resistant mutant of Arabidopsis, auxl, was restored when the synthetic auxin 1-naphthaleneacetic acid (NAA) was added to the growth medium; auxl roots were not resistant to NAA. Neither indole-3-acetic acid nor 2,4-dichlorophenoxyacetic acid had the same effects as NAA. These differential effects of the three auxins on auxl defects suggest that A UX1 may encode the auxin influx carrier according to the model proposed by Delbarre et al. [(1996) Key words: Arabidopsis thaliana -A UX1 -Auxin influx carrier -Auxin-resistant mutant -Gravitropism of rootGrowth of root.auxl is an auxin-resistant mutant of Arabidopsis that can grow in the presence of natural and synthetic auxins, IAA and 2,4-D (Maher and Martindale 1980, Mirza et al. 1984). It is also resistant to ethylene (Pickett et al. 1990, Roman et al. 1995 and inhibitors of the auxin efflux carrier (Fujita and Syono 1996). Morphological defects of auxl are confined to roots; in particular the gravitropic response of auxl roots is severely impaired (Maher and Martindale 1980, Mirza et al. 1984, Mirza 1987, Okada and Shimura 1992, Roman et al. 1995, Timpte et al. 1995. Recently the A UX1 gene has been cloned by T-DNA tagging, and shown to encode a protein similar to amino-acid permeases. The structural similarity of IAA to tryptophan suggests that AUX1 protein could be an auxin influx carrier (Bennett et al. 1996). In fact, it has been suggested that auxl is defective in auxin uptake since the latent period for inhibition of root growth by auxin was longer for roots of auxl than for other auxin-resistant mutants (Evans et al. 1994).If the auxl phenotype results from lower intracellular concentrations of auxin due to the lack of a functional auxin influx carrier, exogenously added auxin may rescue defects in auxl. We therefore determined the effects of Abbreviations: NAA, 1-naphthaleneacetic acid; SD, standard deviation. 1 To whom correspondence should be addressed. Fax: +81-11-706-2253. e-mail: kty@ees.hokudai.ac.jp IAA, NAA and 2,4-D on the gravitropic responses and growth of auxl roots. To our surprise, we found that only NAA corrected the aberrant gravitropic response to the normal level, and that auxl was not resistant to NAA at all. Discussion of these results with reference to differential uptake of auxins by tobacco suspension-cultured cells reported by Delbarre et al. (1996) strongly suggests that the AUX1 product is the auxin influx carrier.Seeds of auxl, derived from Arabidopsis thaliana Columbia ecotype, were surface-sterilized, as described by Watahiki et al. (1995), and were plated on nutrient agar that contained half-strength MS salts (Murashige and Skoog 1962), l%(w/v) sucrose, half-strength B5 vitamin (Gamborg et al. 1968), and l%(w/v) agar. They were kept at 4°C for two d, and then at 22°C for 24 h under continuous white light (76 W m~2) to induce germination. They were further grown at 22°C in darkness for 4 d on vertically-held plates. Photographs of the seedlings were taken from the back of th...

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Both GERD prevalence and the prevalence of hernia were significantly higher in obese subjects, and the prevalence of GERD in subjects who had gained weight was also significantly higher. From these results, it was concluded that obesity is a risk factor for GERD in Japan.