bluuebunny/crossref_metadata_2025_split huggingface dataset:
Management of insecticide resistance in Oriental fruit moth (Grapholita molesta; Lepidoptera: Tortricidae) populations from Ontario
Authors: Kanga Lambert HB , Pree David J , van Lier Jennifer L , Walker Gerald M 
Published: July 2003

AbstractThe development of resistance in the Oriental fruit moth, Grapholita molesta (Busck) to organophosphorus (OP) insecticides (azinphos‐methyl and phosmet) is a serious threat to the tender fruit industry in Ontario (50% crop losses in 1994). Resistance to carbamate insecticides and increased survival of field‐collected moths at diagnostic concentrations of pyrethroids were widespread. As a result, four different treatment regimes were tested to manage resistance in G molesta, and the changes in resistance frequencies under each treatment regime were monitored from 1996 to 1999. The data indicated that the levels of resistance were significantly influenced by the various treatment regimes. The seasonal pattern of resistance was similar for all treatment regimes, in that resistance peaked in mid‐season and declined in the late season. Levels of resistance in G molesta to OPs decreased from 55% to 14% and that to pyrethroids declined from 30% to 10% from 1996 to 1999 under a treatment regime consisting of endosulfan–organophosphate–pyrethroid rotation. Similarly, under a treatment regime implemented in commercial orchards (organophosphate–pyrethroid rotation), resistance to OP insecticides declined from 50% to 12% and resistance to pyrethroids evolved to around 16%. The overall data indicated that resistance was unstable; a strategy based on rotation of insecticides by class for each generation of G molesta was successful in managing resistance to both OP and pyrethroid insecticides. The rotational strategy has been widely adopted by growers and is applied to ca 85% of the acreage. For the Department of Agriculture and Agri‐Food, Government of Canada, © Minister of Public Works and Government Services Canada 2003. Published for SCI by John Wiley & Sons, Ltd.
Vitamin K requirement in Danish anticoagulant‐resistant Norway rats (Rattus norvegicus)
Authors: Markussen Mette DK , Heiberg Ann‐Charlotte , Nielsen Robert , Leirs Herwig 
Published: July 2003

AbstractResistance to warfarin has been connected to an increase in dietary requirement for vitamin K in British strains of the Norway rat, Rattus norvegicus (Berk). This study examines vitamin K requirement of Danish anticoagulant‐resistant Norway rats using a vitamin K deficient feeding test. Wild bromadiolone‐resistant rats sampled from different localities in Denmark and rats from bromadiolone‐resistant and susceptible laboratory strains were fed on a vitamin K deficient diet over a maximum period of 15 days. Development of vitamin K deficiency, measured as reduced blood‐clotting capacity, took place in 43% of the Danish resistant rats and was independent of sex, treatment with supplementary vitamin K3 and sampling locality. Development of deficiency was slower for resistant rats that were supplemented with vitamin K3 prior to the feeding test, suggesting storage of the vitamin K in a vitamin body pool. Intraperitoneal administration of vitamin K1 revealed that 80 µg vitamin K1 kg−1 bodyweight was sufficient to restore normal blood clotting activity in deficient rats, while 60 µg vitamin K1 kg−1 bodyweight was insufficient. We conclude that vitamin K requirement is moderately increased in Danish homozygous resistant rats whereas heterozygous resistant rats only have a minor increase in vitamin K requirement compared with susceptible rats. We found no indication of different resistance types being present in our test material since vitamin K requirement was not different between rats from separate sampling localities. Copyright © 2003 Society of Chemical Industry
The toxic and anti‐feedant activity of 2H‐pyridazin‐3‐one‐substituted 1,3,4‐oxadiazoles against the armyworm Pseudaletia separata (Walker) and other insects and mites
Authors: Huang Qingchun , Qian Xuhong , Song Gonghua , Cao Song 
Published: July 2003

AbstractThe toxicities and anti‐feedant activities of thirteen asymmetrical 1,3,4‐oxadiazoles containing a 2H‐pyridazin‐3‐one group were investigated. The compounds were shown to possess considerable activity in retarding the development of larvae of a number of Lepidoptera, but they were all inactive against Homoptera, Diptera and Acarina. The compounds had powerful anti‐feedant activity comparable with that of azadirachtin. The toxic symptoms of the poisoned larvae indicated that the compounds were novel insect growth regulators with a mode of action that might be similar to the chitin‐synthesis inhibition of oxadiazole compounds and/or the juvenile hormone effect of pyridazinone compounds. Copyright © 2003 Society of Chemical Industry
Flufenacet herbicide treatment phenocopies the fiddlehead mutant in Arabidopsis thaliana
Authors: Lechelt‐Kunze Christa , Meissner Ruth C , Drewes Mark , Tietjen Klaus 
Published: July 2003

AbstractIn order to study the mode of action of herbicides we conducted a pilot study analysing phenotype and gene expression of flufenacet‐ and benfuresate‐treated Arabidopsis thaliana (L) Heynhoe plants. Treatments with either herbicide caused phenocopies of the known Arabidopsis mutant fiddlehead, displaying fused organs and the typical fiddlehead‐like inflorescence. Herbicide treatments of other plant species, including monocots, also gave rise to analogous organ fusions, indicating the presence of the target in a broad range of plants. Furthermore, many other herbicides with a proposed similar mode of action, eg chloroacetanilides, produced comparable fusion phenotypes in plants. The fiddlehead gene encodes a putative very‐long‐chain fatty acid elongase (VLCFAE), which corroborates earlier biochemical results pointing to the inhibition of VLCFA synthesis as mode of action of flufenacet. Gene expression profiles of herbicide‐treated plants using the first 8247 gene Arabidopsis gene array of Affymetrix provided additional clues in support of inhibition of VLCFA synthesis. We discuss fiddlehead‐like elongases as plant specific targets for flufenacet and many other herbicides. Copyright © 2003 Society of Chemical Industry
Contact activity of difenzoquat differs from that of paraquat
Authors: Li Zhaohu , Nandula Vijay K , Messersmith Calvin G 
Published: July 2003

AbstractDifenzoquat herbicide is used for post‐emergence control of wild oat (Avena fatua L) in small grain crops. Its mechanism of action is not known, but appears to have both paraquat‐like contact activity and systemic growth‐inhibition activity. Experiments were conducted in vitro to compare the contact activity of difenzoquat and paraquat, to examine the contact activity of difenzoquat in difenzoquat‐resistant (accession LCS) and ‐susceptible (accession SB 18) A fatua biotypes and ‐tolerant ‘Ernest’ and ‐susceptible ‘Verde’ hard red spring wheat (Triticum aestivum L) cultivars, and to investigate the role of differential DNA synthesis as a mechanism for difenzoquat resistance. Difenzoquat at 1 mM induced significant electrolyte leakage from resistant and susceptible A fatua leaf tissue in both light and dark, but paraquat at 1 mM induced electrolyte leakage only in light and not in dark. Difenzoquat at 1 mM under light induced more electrolyte leakage from resistant and susceptible A fatua than from tolerant ‘Ernest’ and susceptible ‘Verde’ wheat. Paraquat under light conditions induced more electrolyte leakage than difenzoquat, but no significant differences among A fatua accessions and wheat cultivars were detected. Difenzoquat under light did not decrease chlorophyll levels for either A fatua accessions or wheat cultivars, whereas paraquat decreased chlorophyll content of all four plant types. Inhibition of DNA synthesis was not significantly different between susceptible and resistant A fatua, but was significantly greater in susceptible ‘Verde’ than tolerant ‘Ernest’ wheat. These data suggest that difenzoquat and paraquat, have different modes of contact activity. Copyright © 2003 Society of Chemical Industry
Diagnosis of dehydratase inhibitors in melanin biosynthesis inhibitor (MBI‐D) resistance by primer‐introduced restriction enzyme analysis in scytalone dehydratase gene of Magnaporthe grisea
Authors: Kaku Koichiro , Takagaki Makiichi , Shimizu Tsutomu , Nagayama Kozo 
Published: July 2003

AbstractWe have established a simple diagnosis method for rice blast fungus resistant to MBI‐D. This involves the preparation of PCR templates directly from the lesions in combination with primer‐introduced restriction enzyme analysis PCR (PIRA‐PCR). Copyright © 2003 Society of Chemical Industry
Comparative evaluation of four trityl‐type amidomethyl polystyrene resins in Fmoc solid phase peptide synthesis
Authors: Zikos Christos , Livaniou Evangelia , Leondiadis Leondios , Ferderigos Nikolas , Ithakissios Dionyssis S. , Evangelatos Gregory P. 
Published: July 2003

AbstractFour trityl‐type (i.e. non‐substituted trityl‐, o‐Cl‐trityl‐, o‐F‐trityl‐ and p‐CN‐trityl‐) amidomethyl polystyrene resins were evaluated comparatively, in terms of the stability of the trityl‐ester bond in slightly acidic dichloromethane solutions, and the p‐CN‐trityl‐amidomethyl polystyrene resin was found to be the most stable of them. The above resins were applied, in parallel with Wang benzyl‐type resin, well known for its stability in mild acidic conditions, to the Fmoc solid phase synthesis of the 43‐amino acid residue long bioactive peptide thymosin beta‐4. Independent of their differences in acid sensitivity, the resins seemed to function equally well under the conditions used, since pure thymosin beta‐4 was obtained with a final yield of approximately 30% from each resin. The trityl‐type amidomethyl polystyrene resins were also applied, in parallel with the Wang resin, to the Fmoc solid phase synthesis of a bioactive peptide containing proline at its C‐terminus, i.e. the N‐terminal tetrapeptide of thymosin beta‐4, AcSDKP. In this case, the best yield (87%) was obtained with the o‐Cl‐trityl‐amidomethyl polystyrene resin, which may be the resin of choice, of those studied, for the Fmoc solid phase peptide synthesis. Copyright © 2003 European Peptide Society and John Wiley & Sons, Ltd.
Synthesis of the C‐terminal domain of the tissue inhibitor of metalloproteinases‐1(TIMP‐1)
Authors: Bódi József , Mihala Nikolett , Hajnal Andrea , Medzihradszky Katalin F. , Süli‐Vargha Helga 
Published: July 2003

AbstractAccording to recent investigations, the C‐terminal domain of the tissue inhibitor of matrix metalloproteinases‐1 (TIMP‐1) is responsible for some biological effects that are independent of the enzyme‐inhibiting effect of the N‐terminal domain of the molecule. The C‐terminal domain has been prepared for structure–biological activity investigations. After the chemical synthesis and the folding of the linear peptide, LC‐MS and MALDI‐MS analysis revealed that two isomers with different disulphide bond arrangements were formed. Since more than 30 folding experiments resulted in products with a very similar HPLC‐profile, it was concluded that in the absence of the TIMP‐1 N‐terminal domain no entirely correct folding of the C‐terminal domain occurred. Furthermore, it was observed that, in spite of several purification steps, mercury(II) ions were bound to the 6SH‐linear peptide; it was demonstrated—using disulphide bonded TIMP‐1(Cys145‐Cys166) as a model—that mercury(II) ions can cause peptide degradation at pH 7.8 as well as in 0.1% trifluoroacetic acid. Copyright © 2003 European Peptide Society and John Wiley & Sons, Ltd.
Isolation of a napin‐like polypeptide with potent translation‐inhibitory activity from chinese cabbage (Brassica parachinensis cv green‐stalked) seeds
Authors: Ngai Patrick H. K. , Ng T. B. 
Published: July 2003

AbstractA heterodimeric napin‐like polypeptide was isolated from Brassica parachinensis seeds with a procedure involving ion exchange chromatography on DEAE‐cellulose, affinity chromatography on Affi‐gel blue gel, FPLC‐ion exchange chromatography on Mono S and FPLC‐gel filtration on Superdex 75. The N‐terminal sequence of the 5 kDa subunit of the polypeptide (PAGPFRIPKKRKKEE) showed high homology with other 2S storage proteins like napins and albumins. The polypeptide potently inhibited translation in a cell free system with an IC50 of 6.2 nM. The translation‐inhibiting activity of the polypeptide was relatively stable in the pH range 6–11 and in the temperature range 10–50°C. Copyright © 2003 European Peptide Society and John Wiley & Sons, Ltd.
The use of NMR chemical shifts to analyse the MD trajectories: simulation of bovine pancreatic trypsin inhibitor dynamics in water as a test case for solvent influences
Authors: Busetta Bernard , Picard Philippe , Precigoux Gilles 
Published: July 2003

AbstractIn this paper the NMR secondary chemical shifts, that are estimated from a set of 3D‐structures, are compared with the observed ones to appraise the behaviour of a known x‐ray diffraction structure (of the bovine pancreatic trypsin inhibitor protein) when various molecular dynamics are applied. The results of a 200 ps molecular dynamics under various conditions are analysed and different ways to modify the molecular dynamics are considered. With the purpose of avoiding the time‐consuming explicit representation of the solvent (water) molecules, an attempt was made to understand the role of the solvent and to develop an implicit representation, which may be refined. A simulation of hydrophobic effects in an aqueous environment is also proposed which seems to provide a better approximation of the observed solution structure of the protein. Copyright © 2003 European Peptide Society and John Wiley & Sons, Ltd.
Lipid and carbohydrate based adjuvant/carriers in immunology
Authors: McGeary Ross P. , Olive Colleen , Toth Istvan 
Published: July 2003

AbstractThis review discusses various issues regarding vaccines; what are they and how they work, safety aspects, the role of adjuvants and carriers in vaccination, synthetic peptides as immunogens, and new technologies for vaccine development and delivery including the identification of novel adjuvants for mucosal vaccine delivery. There has been a recent increase of interest in the use of lipids and carbohydrates as adjuvants, and so a particular emphasis is placed on adjuvants derived from lipids or carbohydrates, or from both. Copyright © 2003 European Peptide Society and John Wiley & Sons, Ltd.
Disruption of the β‐sheet structure of a protected pentapeptide, related to the β‐amyloid sequence 17–21, induced by a single, helicogenic Cα‐tetrasubstituted α‐amino acid
Authors: Formaggio Fernando , Bettio Andrea , Moretto Vittorio , Crisma Marco , Toniolo Claudio , Broxterman Quirinus B. 
Published: July 2003

AbstractFifteen years ago it was shown that an α‐aminoisobutyric acid (Aib) residue is significantly more effective than an L‐Pro or a D‐amino acid residue in inducing β‐sheet disruption in short model peptides. As this secondary structure element is known to play a crucial role in the neuropathology of Alzheimer's disease, it was decided to check the effect of Aib (and other selected, helix inducer, Cα‐tetrasubstituted α‐amino acids) on the β‐sheet conformation adopted by a protected pentapeptide related to the sequence 17–21 of the β‐amyloid peptide. By use of FT‐IR absorption and 1H NMR techniques it was found that the strong self‐association characterizing the pentapeptide molecules in weakly polar organic solvents is completely abolished by replacing a single residue with Aib or one of its congeners. Copyright © 2003 European Peptide Society and John Wiley & Sons, Ltd.
Electronic density from structure factor determination in small deformed crystals
Authors: Putz Mihai V. 
Published: July 2003

AbstractStarting from the integrated reflectivity expression, in the framework of dynamical X‐ray diffraction in small deformed crystals, there are derived the analytical formulae of Pendellösung and the associated structure factor, within symmetrical Laue diffraction geometry without absorption. The current approach provides the electronic density Fourier expansion. A movie for the electronic maps counting different elastic deformations is computed for the case of Si (fcc) structure. © 2003 Wiley Periodicals, Inc. Int J Quantum Chem 94: 222–231, 2003
Algebraic derivation of the iterative‐perturbative method as a global squeezing and displacement transformation
Authors: Urdaneta I. , Paz J. L. 
Published: July 2003

AbstractWe make use of iterative Bogoliubov transformations (IBT) and employ a procedure derived by Mundarain et al. to derive an approximate analytic expression for the evolution operator of a system consisting of a quartic oscillator coupled to a time‐dependent electric field. As a result, this expression resumes the whole iterative process as a global squeezing and displacement transformation in which the compression coefficients and translation parameters are obtained explicitly, thus giving a complete analytic structure to the process that supports and complements the conventional IBT and the bilinear approximation Echave, J., et al. J Chem Phys 1990, 92, 1188, which are mainly numerical and semiclassic approaches respectively. © 2003 Wiley Periodicals, Inc. Int J Quantum Chem 94: 179–188, 2003
Intramolecular proton transfer induced by divalent alkali earth metal cation in the gas state
Authors: Ai Hongqi , Bu Yuxiang , Li Ping 
Published: July 2003

AbstractInteractions between divalent alkali earth metal (DAEM) ions M (MBe, Mg, Ca, Sr, Ba) and the second stable glycine conformer in the gas phase, which can transfer into the ground‐state glycine‐M2+ (except the glycine–Be2+) among each corresponding isomers when these divalent metal ions are bound, are studied at the hybrid three‐parameter B3LYP level with three different basis sets. Proton transfers from the hydroxyl to the amino nitrogen of the glycine without energy barriers have been first observed in the gas phase in these glycine–M2+ systems. The interaction between the glycine and these DAEM ions except beryllium and magnesium ion only create an amino hydrogen pointing to the original hydroxyl due to their weaker interaction relative to those divalent transition metal (DTM) ion‐bound glycine derivatives, being obviously different from that between the glycine and DTM ions, in which two amino hydrogens point to the original hydroxyl oxygen when these metal‐chelated glycine derivatives are produced. The interaction energy between the glycine and divalent magnesium would be the boundary of one or two amino hydrogens pointing to the hydrogyl oxygen, i.e., the −170.3 kcal/mol of binding energy is a critical point. Similar intramolecular proton transfer has also been predicted for those DTM ion‐chelated glycine systems; however, that in the gas state has not been observed in the monovalent metal ion‐coordinated glycine systems. The binding energy between some monovalent TM ion and the glycine is similar to that of the glycine–Ba2+, which has the lowest binding strength among these DAEM–ion chelated glycine complexes. The difference among them only lies in the larger electrostatic and polarized effects in the latter, which favor the stability of the zwitterionic glycine form in the gas phase. According to these observations, we predict that the zwitterionic glycine would exist in the field of two positive charges in the gas phase. © 2003 Wiley Periodicals, Inc. Int J Quantum Chem 94: 205–214, 2003
Zirconia‐based column high‐performance liquid chromatography/atmospheric pressure photoionization tandem mass spectrometric analyses of drug molecules in rat plasma
Authors: Hsieh Yunsheng , Merkle Kara , Wang Ganfeng 
Published: July 2003

AbstractA method using zirconia‐based column high‐performance liquid chromatography (HPLC) interfaced with an atmospheric pressure photoionization (APPI) source and a tandem mass spectrometer (MS/MS) was developed for the quantitative determination of new chemical entities in rat plasma in support of pharmacokinetics studies. The ionization suppression resulting from endogenous components of the biological matrices on the quantitative zirconia‐based column HPLC/APPI‐MS/MS method was investigated using the post‐column infusion technique. The analytical results for ‘rapid rat pharmacokinetics’ for 12 drug discovery compounds, obtained by both silica‐based phase (S‐phase) and zirconia‐based phase (Z‐phase) chromatographic separation, are in good agreement in terms of accuracy. The application of a Z‐phase column for high‐temperature fast HPLC/MS/MS methods was explored to reduce the analysis time from 3 min to 30 s for column temperatures of 25–110°C, respectively. The chromatographic retention times and peak responses of all analytes were found to be reproducible under high‐temperature conditions following 100 continuous injections, with %CV less than 0.4 and 5, respectively. Copyright © 2003 John Wiley & Sons, Ltd.
Intact protein analysis by matrix‐assisted laser desorption/ionization tandem time‐of‐flight mass spectrometry
Authors: Lin Melanie , Campbell Jennifer M. , Mueller Dieter R. , Wirth Urs 
Published: July 2003

AbstractDirect tandem mass spectrometric (MS/MS) analysis of small, singly charged protein ions by tandem time‐of‐flight mass spectrometry (TOFMS) is demonstrated for proteins up to a molecular mass of 12 kDa. The MALDI‐generated singly charged precursor ions predominantly yield product ions resulting from metastable fragmentation at aspartyl and prolyl residues. Additional series of C‐terminal sequence ions provide in some cases sufficient information for protein identification. The amount of sample required to obtain good quality spectra is in the high femtomolar to low picomolar range. Within this range, MALDI‐MS/MS using TOF/TOF™ ion optics now provides the opportunity for direct protein identification and partial characterization without prior enzymatic hydrolysis. Copyright © 2003 John Wiley & Sons, Ltd.
Investigation of apparent mass deviations in electrospray ionization tandem mass spectrometry of a benzophenone‐labeled peptide
Authors: Leite John F. , Dougherty Dennis A. , Lester Henry A. , Shahgholi Mona 
Published: July 2003

AbstractIn a previous study utilizing benzophenone‐based topological probes to study conformationally dependent changes in mouse muscle nicotinic acetylcholine receptor (nAChR) topology, electrospray ionization tandem mass spectrometric (ESI‐MS/MS) analysis led to a consistent −2.0 Da mass deviation from expected values. In the present study a synthetic peptide, corresponding to nAChR α1 subunit residues 130–139, was photolabeled. MS/MS analysis of this peptide using an ion trap confirmed the previously observed mass deviation, associated only with fragment ions that contain the incorporated benzophenone moiety. Analysis of peak profiles for the photolabeled ions does not indicate the typical ‘peak fronting’ that produces a mass shift when labile ions are prematurely ejected from the ion trap. Rather, hydrogen/deuterium (H/D) exchange experiments support the hypothesis that a chemical rearrangement involving phenyl migration and ketone formation has formed an unexpected oxidized peptide, with molecular mass 2 Da less than that expected, that is isolated for collision‐induced dissociation in the ion trap together with the predicted precursor due to the broad ion isolation window specified. Copyright © 2003 John Wiley & Sons, Ltd.