Abstract: A method for detecting the presence of a target nucleic acid sequence in a sample, the method comprising (a) amplifying the target nucleic acid so that the product of the amplification reaction includes a purine rich region, (b) contacting the sample during the amplification with a peptide nucleic acid able to bind to at least a portion of the target sequence; and (c) detecting the presence of triplex DNA structures. The detection is suitably effected directly, for example using a surface plasmon resonance detector.

Abstract: A method of enhancing expression of a desired protein at mucosal effector sites, the method including placing the protein to be expressed under the control of a promoter having SEQ ID NO: 2, SEQ ID NO: 3 or SEQ ID NO: 4, or a fragment or variant of any of these that has promoter activity, and causing expression in mucosal cells. Constructs used in the methods, as well as suitable recombinant gut-colonising microorganisms such as a Salmonella spp., are also described. Such organisms are useful in the preparation of vaccines.

Abstract: A ferroelectric liquid crystal display panel comprises an addressable matrix of pixels and an arrangement for selectively addressing each pixel within a series of addressing frames in order to vary the transmission level of the pixel relative to the transmission levels of the other pixels. The addressing arrangement utilizes a temporal dither (TD) addressing scheme for addressing each pixel within each frame with different combinations of temporal dither signals applied to separately addressable temporal bits within the frame to produce different overall transmission levels.

Abstract: Compounds of formula ##STR1## are provided which may be used in a variety of devices including liquid crystal devices, piezoelectric devices, pyroelectric devices and in optical recording media, wherein X.sub.1 and X.sub.2 are independently selected from H, CN, COCH.sub.3, CO.sub.2 CH.sub.3, m=at least 5; X.sub.3 and X.sub.4 are independently selected from formula (IA), ##STR2## wherein Y is selected from COO, OCO, O, S, CHOH, CHF, CH.sub.2 ; Q=(CH.sub.2).sub.n wherein one or more non-adjacent methylenes may be replaced by O and n=1-20; Z is selected from O, S, single covalent bond, COO, OCO; when Y is CH2 then n may also be O; formula (A) ##STR3## represents any mesogenic group; X3 and X.sub.4 are also independently selected from H, OH, OCOR.sup.1, COOH, CO.sub.2 R.sup.1 (CH.sub.2).sub.p OH, (CH.sub.2).sub.p CO.sub.2 H, --(CH.sub.2).sub.p OR.sup.1 or --(CH.sub.2).sub.p CO.sub.2 R.sup.1 and p=1-20, R.sup.1 =H or C.sub.1=16 alkyl, when R.sup.1 =C.sub.2-16 alkyl the terminal Ch.sub.