Synthesis and characterization of regiorandom and regioregular poly(3-octylfuran).

Poly(3-octylfuran) has been synthesized with three regioregularities: P3OF-95, P3OF-75, and P3OF-50, where the number signifies the percentage HT content. The 95% HT material is highly crystalline with a structure similar to that of HT-poly(3-octylthiophene), P3OT. The lamellar spacing is 22.1 A and the pi-stacking distance is 3.81 A. UV-vis spectroscopy reveals that P3OF-95 is aggregated in CHCl(3) solution, and solid films of P3OF-95, but not P3OF-75 or -50, show Davydov and exciton band splitting due to the interactions of the pi-systems in the stacked morphology. An estimate of the Davydov splitting is 0.15 eV (1200 cm(-1)). P3OF is reversibly oxidized at 0.32 V vs ferrocene/ferrocenium, but increasing the potential to 1.15 V leads to irreversible oxidation. Films of P3OF may be p-doped with iodine vapor. Doped P3OF-95 and -75 films have electrical conductivities of 10(-2) and 10(-7) S/cm, respectively. The UV-vis-NIR spectra of the iodine-doped films are interpreted in terms of molecular-like transitions involving the LUMO, HOMO, HOMO-1, and transitions across a Peierls distortion-induced gap in the intermolecular conduction band that is formed by the overlap of the pi-systems of the stacked partially oxidized chains. The conduction band gap estimated for P3OF-95 is 0.34 eV, and that for P3OF-75 is 0.9 eV. The P3OF samples are thermally stable in N(2) atmosphere to between 275 degrees C (P3OF-50) and 380 degrees C (P3OF-95), but suffer thermal oxidation above 150 degrees C or light-induced oxidation at room temperature.

Asymmetric syntheses of fused bicyclic compounds by conjugate additions of allylic organolithium species to activated olefins and subsequent cyclizations.

[reaction: see text]. Addition of the configurationally stable organolithium species produced by enantioselective deprotonation of N-Boc-N-(p-methoxyphenyl) allylamines to alpha,beta-unsaturated carbonyl compounds affords 1,4-addition products in good yields with high diastereomeric and enantiomeric ratios. Further transformations of these compounds provide [3.3.0]-, [4.3.0]-, [5.3.0]-, and [5.4.0]-carbocycles and heterocycles with high stereoselectivities.

Dynamic thermodynamic resolution: control of enantioselectivity through diastereomeric equilibration.

A theoretical foundation, tools for recognition and control, and recent examples of a class of asymmetric transformation termed dynamic thermodynamic resolution are presented. Enantioselective reaction pathways that involve an induced diastereomeric equilibration to intermediates, which are configurationally stable on the time scale of a subsequent reaction, are illustrated. Dynamic thermodynamic resolution differs from the classic, well-documented pathways of kinetic resolution and dynamic kinetic resolution in that equilibration and resolution can be operative on one system in separate controllable steps. This approach offers a high level of flexibility and provides multiple opportunities for optimization of enantioselectivity.

The promoter of the plant defensin gene PDF1.2 from Arabidopsis is systemically activated by fungal pathogens and responds to methyl jasmonate but not to salicylic acid.

The plant defensin PDF1.2 has previously been shown to accumulate systemically via a salicylic acid-independent pathway in leaves of Arabidopsis upon challenge by fungal pathogens. To further investigate the signalling and transcriptional processes underlying plant defensin induction, a DNA fragment containing 1184 bp and 1232 bp upstream of the transcriptional and translational start sites, respectively, was cloned by inverse PCR. To test for promoter activity this DNA fragment was linked to the beta-glucuronidase (GUS)-encoding region of the UidA gene as a translational fusion and introduced into Arabidopsis ecotype C-24. Challenge of the transgenic plants with the fungal pathogens Alternaria brassicicola and Botrytis cinerea resulted in both local and systemic induction of the reporter gene. Wounding of the transgenic plants had no effect on GUS activity. Treatment of the transgenic plants with either jasmonates or the active oxygen generating compound paraquat strongly induced the reporter gene. In contrast, neither salicylate nor its functional analogues 2,6-dichloroisonicotinic acid and 1,2,3-benzothiodiazole-7-carbothioic acid S-methyl ester resulted in reporter gene induction. These results are consistent with the existence of a salicylic acid-independent signalling pathway, possibly involving jasmonates as regulators, that is triggered by pathogen challenge but not by wounding. The transgenic plants containing the PDF1.2-based promoter-reporter construct will provide useful tools for future genetic dissection of this novel systemic signalling pathway.

A peroxidase gene promoter induced by phytopathogens and methyl jasmonate in transgenic plants.

The expression of two closely related peroxidase isogenes, Shpx6a and Shpx6b, of the legume Stylosanthes humilis was studied using isogene-specific reverse transcriptase PCR techniques. Results indicated that transcripts of both genes were rapidly induced following inoculation with the fungal pathogen Colletotrichum gloeosporioides, wounding and treatment with the defense regulator methyl jasmonate (MeJA). In contrast treatment of leaves of S. humilis with abscisic acid (ABA) and salicylic acid (SA) did not induce transcripts of either isogene. A genomic clone containing the Shpx6b gene was isolated and 594 bp of 5' sequence upstream of the translation start was fused in frame to the coding region of the uidA reporter gene and introduced into tobacco. Expression from the Shpx6b promoter in transgenic plants was determined by histochemical staining and quantitative assays of beta-glucuronidase (GUS). In transgenic tobacco, GUS expression was detected in cotyledons, vascular cells of young leaves, anthers, pollen, and the stigma and style. Wounding of the tobacco plants produced very localized GUS staining. Much more extensive staining for GUS was observed following inoculation of tobacco leaves with conidia of the fungal pathogen Cercospora nicotianae and the inoculation of wound sites with mycelium of the Oomycete pathogen Phytophthora parasitica var. nicotianae. Treatment of mature leaves with methyl jasmonate induced GUS activity while treatment with ABA, SA, and H2O2 had no effect. A similar strong induction of GUS activity was measured in young transgenic seedlings germinated on MeJA while some, but much weaker, induction of GUS activity was observed in seedlings treated with SA. The sequence of the promoter contained motifs homologous to putative cis elements in other plant genes responsive to MeJA. The Shpx6b gene is the first plant peroxidase gene shown to be induced by both microbial pathogens and MeJA and its promoter will be useful for investigations of signaling processes during fungal infection and for the expression of foreign gene products at infection sites.

Gypsy-class retrotransposon sequences in organisms related to the leaf mould fungus, Cladosporium fulvum.

Gypsy retrotransposons are a major branch of retroid elements and have been found in a wide diversity of eukaryotic organisms including CfT-1 in the tomato leaf mould pathogen, the fungus Cladosporium fulvum (syn. Fulvia fulva). We have examined organisms that are either ecologically or phylogenetically related to C. fulvum, for elements related to CfT-1. Using PCR and Southern hybridisation, similar sequences were found only in the co-genic fungus Cladosporium cladosporioides. This finding confirms the apparent ubiquity of retroelements, suggests that the phylogeny of retrotransposons is consistent with the phylogeny of their hosts and argues against frequent horizontal gene transfer.

Differential expression of peroxidase isogenes during the early stages of infection of the tropical forage legume Stylosanthes humilis by Colletotrichum gloeosporioides.

Infection of Stylosanthes humilis by the fungal phytopathogen Colletotrichum gloeosporioides is associated with an increase in peroxidase enzyme activity within 24 h postinoculation. Peroxidase gene expression was investigated as a first step towards understanding the regulation and functional importance of this host response to fungal attack. Four distinct cDNAs Shpx 2, 5, 6, and 12, isolated from a cDNA library of S. humilis contained deduced amino acid (aa) sequence motifs characteristic of peroxidases. Three of these (Shpx 2, 5, and 6) were full-length and their deduced proteins each fell into a different homology group based on comparisons with other plant peroxidases. Each cDNA appeared to hybridize to only one or two genes in S. humilis. mRNAs corresponding to Shpx2, Shpx6, and Shpx12 were expressed relatively abundantly in young leaves, with lesser expression of Shpx2 and Shpx6 and no expression of Shpx12 detected in roots. No expression of these genes was detected in stems or old leaves. The mRNA of Shpx5 was relatively abundant in stems and to a lesser extent in young leaves. However, infection of young leaves with C. gloeosporioides greatly increased expression of the mRNAs of Shpx2 and Shpx6 but not Shpx5 nor Shpx12 compared to mock-inoculated controls. The mRNA of Shpx6 was strongly induced by the pathogen 4 h postinoculation, a time which precedes fungal penetration, while Shpx2 was induced to higher levels than controls at 24 h after inoculation. The mRNAs of both Shpx2 and Shpx6 but not Shpx5 and Shpx12 were also induced by wounding.(ABSTRACT TRUNCATED AT 250 WORDS)

Molecular evidence that diploid Stylosanthes humilis and diploid Stylosanthes hamata are progenitors of allotetraploid Stylosanthes hamata cv. Verano.

Restriction fragment length polymorphism analysis, using peroxidase, O-methyltransferase, phenylalanine ammonia-lyase, and coniferyl alcohol dehydrogenase cDNAs isolated from Stylosanthes humilis, as probes, provided molecular evidence for the genetic origin of the naturally occuring allotetraploid genotype Stylosanthes hamata cv. Verano (2n = 4x = 40). Hybridization patterns strongly suggest that the likely progenitors of S. hamata cv. Verano were a diploid S. humilis (2n = 2x = 20) and a diploid S. hamata (2n = 2x = 20) species.

The phylogeny of the tomato leaf mould fungus Cladosporium fulvum syn. Fulvia fulva by analysis of rDNA sequences.

The nucleotide sequence of part of the ribosomal DNA from races of the fungal tomato pathogen Cladosporium fulvum and other Cladosporium species have been determined. Comparisons of the internal transcribed spacer regions (ITS1 and ITS2) of several C. fulvum races showed complete sequence homology suggesting a recent evolutionary divergence. Comparisons of these nucleotide sequences in the ITS region with those of other Cladosporium species showed the close relationship within the Cladosporium genus. Using the nucleotide sequence of part of the 18s ribosomal subunit from these isolates and comparing them with sequences of some Ascomycetes, Basidiomycetes and Chytridiomycetes, obtained from GenBank, we infer the phylogeny of the Cladosporium species studied here. Our analysis shows that the Cladosporia form a monophyletic group which falls within the order Ascomycotina.

Investigation of the specificity of the interaction between colicin E9 and its immunity protein by site-directed mutagenesis.

Comparison of the amino acid sequences of the C-terminal domain of three DNAase type E colicins has identified six candidate specificity determinants for the interaction of these E colicins with their homologous immunity proteins. We have changed these candidate specificity determinants of colicin E9, using site-directed mutagenesis, to the corresponding amino-acids of colicin E8. A 'mutant' colicin E9, in which four of the six candidate specificity determinants have been changed, demonstrated colicin activity against Escherichia coli indicator strains which carried either the E8imm or the E9imm genes, indicative of a 'novel' E. colicin. After changing all six of the candidate specificity determinants, the resulting colicin E9 'mutant' exhibited a phenotype very similar to that of colicin E8.

An evolutionary relationship between the ColE5-099 and the ColE9-J plasmids revealed by nucleotide sequencing.

The nucleotide sequence of a 1124 bp fragment of the ColE5-099 plasmid which encodes colicin E5 immunity, a lys gene involved in colicin release from the host cell, and the 3' end of the colicin E5 structural gene has been determined. Open reading frames corresponding to the three genes have been located by analogy with similar sequences from other E colicin plasmids. The location of these open reading frames corresponds with the position of the genes as determined by subcloning and transposon mutagenesis. The amino acid sequence of the carboxy-terminal 107 amino acid residues of the colicin E5 gene shows no homology with any other E colicin, suggesting a different mode of action in killing sensitive cells. A comparison of the nucleotide sequence of this region of the ColE5-099 plasmid with that of the equivalent region of the ColE9-J plasmid suggests a close evolutionary relationship between these two plasmids.

Automated nursing documentation: a design perspective.

The concept of an automated nursing documentation system has been subject to casual debate for a number of years. During this time, Hewlett-Packard developed a system that is both adequate and workable from many perspectives (i.e. the Staff Notes Subsystem of the Patient Data Management System-PDMS). This package has been used as the primary method to document patient care for six years in the Critical Care Units of Phoenix Baptist Hospital. With the aid of Baptist Hospitals and Health Systems (BHHS) Design Engineers, it continues to evolve predicated on a singular intent: To provide the type of documentation required by the medical staff. The objective of this paper is multifold. Foremost, generalized criteria are established to provide a vehicle for standardizing the design or evolution of a staff notes package. The generic structure of the PDMS notes subsystem is discussed in regard to its parity with these criteria. Finally, custom modifications and additions to this package will be presented, and recommendations for future enhancements will be outlined.