bluuebunny/crossref_metadata_2025_split huggingface dataset:
Prenatal diagnosis of interstitially satellited 6p
Authors: Chen Chih‐Ping , Chern Schu‐Rern , Lee Chen‐Chi , Chen Wen‐Lin , Wang Wayseen 
Published: June 2004

AbstractObjectivesTo present the prenatal diagnosis of de novo interstitially satellited 6p and a review of the literature.CaseAn amniocentesis was performed at 18 weeks' gestation because of paternal balanced translocation, t(6;14)(p22;p12). Family history of the father showed the derivative chromosomes to be transmitted through at least two generations with three members affected with partial trisomy 6p (6p22 → 6pter).ResultsCytogenetic analysis of the cultured amniocytes revealed an interstitial insertion of a nucleolar organizer region (NOR) in 6p22 and a karyotype of 46,XX, rec(6)ins(6;14)t(6;14)(6pter → 6p22::14p12 →14p12::6p22 → 6qter). Level II ultrasound examinations revealed normal findings. The parents opted to terminate the pregnancy. A 650‐g fetus was delivered at 23 weeks' gestation without any gross abnormalities. Cytogenetic analysis of the cord blood lymphocytes confirmed the prenatal diagnosis.ConclusionsThe present case provides evidence that a de novo interstitial insertion of a NOR into a nonacrocentric chromosome can be derived from a parental balanced reciprocal translocation involving the satellite stalk region of an acrocentric chromosome. The NOR‐inserted chromosome seems to be a harmless variant. However, a de novo interstitial NOR translocation can be pathogenic if there is genomic disruption at the site of translocation, which should be included in genetic counseling and perinatal investigation. Copyright © 2004 John Wiley & Sons, Ltd.
Azo initiator selection to control the curing order in dimethacrylate/epoxy interpenetrating polymer networks
Authors: Dean Katherine M , Cook Wayne D 
Published: June 2004

AbstractDifferential Scanning calorimetry (DSC) and Fourier‐transform infrared (FT‐IR) spectroscopic studies have been undertaken of the cure of interpenetrating polymer networks (IPNs) formed with imidazole‐cured diglycidyl ether bisphenol‐A (DGEBA) and with either diethoxylated bisphenol‐A dimethacrylate (DEBPADM) or bisphenol‐A diglycidyl dimethacrylate (bisGMA), polymerized by a range of azo initiators (AIBN64, VAZ088, VR110 and AZO168). Due to the differing decomposition rates of the azo initiators, the neat dimethacrylate resin either cured faster than (with AIBN64 and VAZO88), or similar to (VR110), or slower than (AZO168), the neat epoxy resin. In the neat DGEBA/1‐methyl imidazole (1‐MeI), DEBPADM/AIBN64, DEBPADM/VAZO88 and DEBPADM/VR110 resins, close to full cure was achieved. For the neat, high‐temperature DEBPADM/AZO168 resin, full cure was not attained, possibly due to the compromise between using a high enough temperature for azo decomposition while avoiding depolymerization or decomposition of the methacrylate polymer. IPN cure studies showed that, by appropriate initiator selection, it was possible to interchange the order of cure of the components within the IPN so that either the dimethacrylate or epoxy cured first. In the isothermal cure of the 50:50 DEBPADM/AIBN64:DGEBA/1‐Mel IPN system, the cure rate of both species was less than in the parent resins, due to a dilution effect. For this system, the dimethacrylate cured first and to high conversion, due to plasticization by the unreacted epoxy, but the subsequent cure of the more slowly polymerizing epoxy component was restricted by the high crosslink density developed in the IPN. After post‐curing, however, high conversion of both reactive groups was observed and the fully cured IPN exhibited a single high‐temperature Tg, close to the Tg values of the parent resins. In the higher‐temperature, isothermal cure of the 50:50 DEBPADM/VR110:DGEBA/1‐Mel IPN system, the reactive groups cured at a similar rate and so the final conversions of both groups were restricted, while in the 50:50 DEBPADM/AZO168:DGEBA/1‐Mel system it was the epoxy which cured first. Both of these higher‐temperature azo‐initiated IPN systems exhibited single Tgs, indicating a single‐phase structure; however, the Tgs are significantly lower than expected, due to plasticization by residual methacrylate monomer and/or degradation products resulting from the high cure temperature. Copyright © 2004 Society of Chemical Industry
Effect of moisture content on mechanical properties, thermal and structural stability and extrudate texture of poly(vinyl chloride)/wood sawdust composites
Authors: Sombatsompop N , Chaochanchaikul K 
Published: June 2004

AbstractMechanical properties and thermal and structural changes of poly(vinyl chloride) (PVC)/wood sawdust composites were assessed with respect to the effect of moisture content, varying from 0.33 to 3.00 % by weight in the composite, for three different wood sawdust contents. The swell ratio and texture characteristics of the composite extrudates were also evaluated. Unique explanations were given to describe changes in the composite properties in terms of molecular interactions between PVC, cellulosic sawdust and moisture, such as dipole–dipole interactions, interfacial defects and bonding, fibre swelling, and moisture evaporation. The results suggest that at low moisture content the tensile modulus decreased and elongation at break of the composites increased with moisture content, the effect being reversed for high moisture content. Tensile strength decreased with increasing moisture content up to 1–2 %, and then unexpectedly increased at higher moisture contents. The effect of moisture content on flexural properties of the composite was similar to that on tensile properties. Impact strength of the composites was considerably improved with moisture content at low sawdust contents (16.7 wt%), and was independent of the moisture content at higher sawdust contents (28.6 and 37.5 wt%). A decrease in decomposition temperature with an increase in polyene content was evidenced with increasing moisture content, while the glass transition temperature did not change with varying moisture content. The extrudate swell ratio increased with the shear rate but remained unaffected by moisture content. The bubbling and peeling‐off in the composite extrudate occurred as a result of the evaporation of water molecules and the application of a high shear rate. Copyright © 2004 Society of Chemical Industry
Predicting mortality of phosphine‐resistant adults of Sitophilus oryzae (L) (Coleoptera: Curculionidae) in relation to changing phosphine concentration
Authors: Daglish Gregory J , Kopittke Rosemary A , Cameron Megan C , Pavic Hervoika 
Published: June 2004

AbstractAdults of a phosphine‐resistant strain of Sitophilus oryzae (L) were exposed to constant phosphine concentrations of 0.0035–0.9 mg litre−1 for periods of between 20 and 168 h at 25 °C, and the effects of time and concentration on mortality were quantified. Adults were also exposed to a series of treatments lasting 48, 72 or 168 h at 25 °C, during which the concentration of phosphine was varied. The aim of this study was to determine whether equations from experiments using constant concentrations could be used to predict the efficacy of changing phosphine concentrations against adults of S oryzae. A probit plane without interaction, in which the logarithms of time (t) and concentration (C) were variables, described the effects of concentration and time on mortality in experiments with constant concentrations. A derived equation of the form Cnt = k gave excellent predictions of toxicity when applied to data from changing concentration experiments. The results suggest that for resistant S oryzae adults there is nothing inherently different between constant and changing concentration regimes, and that data collected from fixed concentrations can be used to develop equations for predicting mortality in fumigations in which phosphine concentration changes. This approach could simplify the prediction of efficacy of typical fumigations in which concentrations tend to rise and then fall over a period of days. Copyright © 2004 Society of Chemical Industry
Degradation and leaching potential of pesticides in biobed systems
Authors: Fogg Paul , Boxall Alistair BA , Walker Allan , Jukes Andrew 
Published: June 2004

AbstractBiobeds provide a potential solution to pesticide contamination of surface waters arising from the farmyard. Previous work has shown that biobeds can effectively treat spills and splashes of pesticide. This study investigated the potential for biobeds to treat much larger volumes and amounts of pesticide waste not only arising from spills but also from washing processes. Two systems were assessed using a range of pesticides at the semi‐field scale, ie a lined biobed system and an unlined system. Studies using the lined biobeds demonstrated that water management was crucial, with biobeds needing to be covered to exclude rain‐water. Once covered, the top of the biobed became hydrophobic, restricting moisture loss and resulting in saturated conditions at depth. The drying out of the top layer coincided with a measured decrease in microbial biomass in the treated biobeds. Applied pesticides were effectively retained within the 0–5 cm layer. Whilst all pesticides tested degraded, low moisture content and microbial activity meant degradation rates were low. Studies using unlined biobeds showed that only the most mobile pesticides leached, and for these >99% was removed by the system, with a significant proportion degraded within 9 months. Peak concentrations of the two most mobile pesticides did however exceeded the limits that are likely to be required by regulatory bodies. However, it is thought that these limits could be reached by optimisation of the system. Copyright © 2004 Society of Chemical Industry
Comparative activity of Choristoneura fumiferana nucleopolyhedrovirus propagated in different hosts
Authors: Ebling Peter M 
Published: June 2004

AbstractThe biological activity of the Ireland strain of Choristoneura fumiferana (Clem) nucleopolyhedrovirus (CfMNPV) propagated in different hosts was determined to provide the basis upon which genetically modified CfMNPV, or other naturally occurring isolates, should be compared. Occlusion bodies (OB) derived from CF‐203 cells were significantly larger and more pathogenic than those propagated in vivo when tested against the fifth larval instar of C fumiferana (Clem) and C occidentalis Freeman. The dose‐responses (LD50 and LD95, expressed as occlusion bodies per larva) of C fumiferana larvae to in vitro‐propagated OBs were 274 and 5785, respectively. The values of LD50 and LD95 to C occidentalis larvae were 19 and 118, respectively. There were no significant differences in pathogenicity or size when OBs propagated in C fumiferana larvae were tested against either insect species, nor were there significant differences for OBs propagated in C occidentalis larvae. The LD50 and LD95 of in vivo‐produced OBs to C fumiferana were 925 and 61 988, respectively. The LD50 and LD95 to C occidentalis were 50 and 453, respectively. OBs propagated in vitro had a mean volume of 13.13 µm3, whereas those propagated in vivo ranged from 0.84 to 1.41 µm3. The median survival time‐responses (ST50) of fifth‐instar C fumiferana or C occidentalis larvae to OBs propagated in vivo were not significantly different from those propagated in vitro at the dosage levels tested. Values of ST50 of C fumiferana larvae to in vitro‐ and in vivo‐produced OBs at dosages causing less than 50% mortality ranged from 9.6 to 9.8 days post‐inoculation (dpi), whereas a LD95 dose resulted in ST50 values ranging from 7.3 to 7.7 days. ST50 values of C occidentalis larvae at dosages causing less than 50% mortality ranged from 9.8 to 10.2 dpi, whereas a LD95 dose resulted in ST50 values ranging from 9.5 to 9.8 dpi. The median feeding cessation time‐response (FT50) of fifth‐instar C fumiferana larvae to OBs propagated in vitro (5.7 days) was not significantly different from the FT50 of those propagated in vivo in either insect species (5.3 and 5.7 days) at the dosage level tested (LD95). No significant differences in FT50 values were observed between OBs propagated in either larval host. The FT50 of C occidentalis larvae to OBs propagated in vitro (7.7 days) was not significantly different from that to those propagated in vivo in C occidentalis larvae (7.6 days), but somewhat different (7.2 days) from that to those propagated in C fumiferana larvae. Results indicate that CfMNPV can be propagated in vivo in either C fumiferana or C occidentalis larvae (or sequentially through both) without alteration in infectivity, although the use of the CF‐203 cell line yields the most biologically active OBs. Copyright © 2004 Society of Chemical Industry
Development of biodegradable aluminium carboxymethylcellulose matrices for mosquito larvicides
Authors: Mathew Nisha , Kalyanasundaram Muthuswami 
Published: June 2004

AbstractThe use of ecofriendly biodegradable controlled‐release formulations of mosquito larvicides could reduce the frequency of application and losses due to degradation of the insecticide compared with conventional formulations. Among the 20 matrices developed by entrapping the organophosphorus mosquito larvicide, fenthion, in carboxymethylcellulose ionotropically cross‐linked with aluminium ions which were studied for release profiles, two matrices, CRF3b and CRF5b, were found to be stable for 16 and 14 weeks under simulated field conditions. The average concentration of fenthion released per week ranged from 0.06 to 3.5 mg litre−1 for CRF3b and 0.09 to 2.72 mg litre−1 for CRF5b. Of these two formulations, CRF3b was the more stable, maintaining the concentration of the active ingredient at the level required to effect mosquito control. The cumulative release of fenthion per pellet was 80% from CRF3b and 72% from CRF5b. Based on the study with fenthion, two similar matrices for triflumuron, a benzoylphenylurea insect growth regulator, STAR3b and STAR5b were developed. These matrices were stable up to 16 weeks with the average concentration of triflumuron released per week ranging from 0.05 to 3.44 mg litre−1 for STAR3b and 0.07 to 2.71 mg litre−1 for STAR5b. The cumulative release of triflumuron per pellet was 75% from STAR3b and 76% from STAR5b. From the results of this study under simulated conditions, it is estimated that the application of four pellets of either fenthion or triflumuron per square metre of the breeding surface may play a useful role in controlling Culex quinquefasciatus Say in larval habitats for about 4 months. Copyright © 2004 Society of Chemical Industry
Distribution and metabolism of D/L‐, L‐ and D‐glufosinate in transgenic, glufosinate‐tolerant crops of maize (Zea mays L ssp mays) and oilseed rape (Brassica napus L var napus)
Authors: Ruhland Monika , Engelhardt Gabriele , Pawlizki Karlheinz 
Published: June 2004

AbstractThe aim of the present study was to determine whether post‐emergence application of glufosinate to transgenic crops could lead to an increase in residues or to the formation of new, hitherto unknown metabolites. Transgenic oilseed rape and maize plants were treated separately with L‐glufosinate, D‐glufosinate or the racemic mixture. Whereas about 90% of the applied D‐glufosinate was washed off by rain and only 5–6% was metabolised, 13–35% of the applied L‐glufosinate remained in the form of metabolites and unchanged herbicide in both transgenic maize and oilseed rape. The main metabolite was N‐acetyl‐L‐glufosinate with total residues of 91% in oilseed rape and 67% in maize, together with small amounts, of 5% in oilseed rape and 28% in maize, of different methylphosphinyl fatty acids. These metabolites were probably formed from L‐glufosinate by deamination and subsequent decarboxylation. The residues were distributed in all fractions of the plants, with the highest contents in treated leaves and the lowest in the grains (0.07–0.3% in maize and 0.4–0.6% in oilseed rape). There was no indication of an accumulation of total residues or of residue levels above the official tolerances for glufosinate. Copyright © 2004 Society of Chemical Industry
Bound and unextractable pesticidal plant residues: chemical characterization and consumer exposure
Authors: Sandermann Heinrich 
Published: June 2004

AbstractPlants are well known to incorporate pesticides into bound and unextractable residues that resist solubilization in common laboratory solvents and are therefore not accessible to standard residue analysis. A characterization of such residues has been proposed for incorporation rates above trigger values of 0.05 mg kg−1 parent pesticide equivalents, or percentage values of 10% (United States Environmental Protection Agency, 1995) or 25% (Commission of the European Communities, 1997) of the total radioactive residue. These trigger values are often exceeded. The present review describes the current status of the chemical characterization and animal bioavailability of bound and unextractable residues that may be xenobiotic in nature or result from natural recycling of simple degradation products. The latter case represents a mechanism of detoxification. Bound residues have been shown to be covalent or non‐covalent in nature. With regard to the plant matrix molecules involved, incorporation into proteins, lignins, pectins, hemicelluloses and cutins has been demonstrated, and four covalent linkage types are known. Animal feeding experiments have revealed cases of low as well as high bioavailability. Many of the studies are limited by experimental uncertainties and by results only being reported as relative percentage values rather than absolute exposure. A preliminary value of absolute exposure from bound and unextractable residues is derived here for the first time from eight case studies. The mean exposure (ca 1.5 mg kg−1 pesticidal equivalents) exceeds some of the existing maximum residue levels (MRLs) of residual free pesticides that are typically in the range of 0.05–1 mg kg−1. A mathematical framework for the correction of current maximum residue levels is presented for cases of highly bioavailable bound residues. As bound pesticidal residues in food plants could represent a source of significant consumer exposure, an experimental test scheme is proposed here. It consists of basic chemical characterization, model digestibility tests and, in exceptional cases, animal bioavailability and additional toxicological studies. Copyright © 2004 Society of Chemical Industry
Preparation of cyclic peptide libraries using intramolecular oxime formation
Authors: Roberts Kade D. , Lambert John N. , Ede Nicholas J. , Bray Andrew M. 
Published: June 2004

AbstractA new method for the synthesis of cyclic head‐to‐side chain peptide libraries has been developed in which the key cyclization step involves reaction between a C‐terminal ketone and an N‐terminal hydroxylamine to form a macrocyclic oxime. This methodology efficiently delivers cyclic products that consist of mixtures of syn and anti isomers. Copyright © 2004 European Peptide Society and John Wiley & Sons, Ltd.
Solution conformational study of nociceptin and its 1–13 and 1–11 fragments using circular dichroism and two‐dimensional NMR in conjunction with theoretical conformational analysis
Authors: Klaudel Lidia , Łȩgowska Anna , Brzozowski Krzysztof , Silberring Jerzy , Wójcik Jacek , Rolka Krzysztof 
Published: June 2004

AbstractConformational studies of nociceptin (NC‐NH2), its fully active fragment, NC(1–13)‐NH2, and two significantly less potent fragments, NC(1–13)‐OH and NC(1–11)‐OH, were conducted in water and TFE solutions by the employment of circular dichroism, and in DMSO‐d6 by 2D NMR spectroscopy in conjunction with theoretical conformational analysis. The conformations of all the peptides studied were calculated taking two approaches. The first assumes multiconformational equilibrium of the peptide studied, which is characterized by a set of conformations (and their statistical weight values) obtained from a global conformational analysis using three methods: the electrostatically driven Monte‐Carlo (EDMC) with the ECEPP/3 force field, the simulated annealing (SA) protocols in the AMBER and CHARMM force fields. The second approach incorporates the interproton distance and dihedral angle constraints into the starting conformation. Calculations were performed using the distance geometry and SA protocol in the CHARMM force field implemented in the X‐PLOR program. The CD experiments indicated that for the active peptides, hydrophobic solvents induced a significantly higher (compared with those remaining) content order, probably a helical structure. Unfortunately, as a result of the conformational flexibility of the peptides, the analysis of conformations obtained with both approaches and different force fields did not allow the selection of any structural elements of the NC peptides that might be connected with their bioactivity. The only common element found in most conformations of the active peptides was a helical character of fragment 8–13, which allowed the side chains of basic amino acid residues to be exposed to the outside of the molecule and probably to interact with the ORL1 receptor. Copyright © 2004 European Peptide Society and John Wiley & Sons, Ltd.
On the mechanisms of oligopeptide reactions in solution and clay dispersion
Authors: Bujdák Juraj , Rode Bernd Michael 
Published: June 2004

AbstractMechanisms of the reactions of representative dipeptides (Gly2, Gly‐Ala), oligopeptides (Gly3, Gly4) and the polypeptide (poly‐Gly)n) in solution and clay suspensions at 85 °C were investigated. The reaction products and their yields were analysed and determined by means of HPLC. Interestingly, hydrolysis, where water molecules act as the reactant, was not the main reaction, even for oligopeptides. Formation of cyclic dipeptides prevailed in the reactions of dimers as well as oligopeptides. The breakdown of oligopeptide molecules proceeded via an intramolecular cyclization reaction. For example, the reaction of Gly3 led to the formation of equal amounts of cyclic dipeptide, c(Gly)2 and Gly. The presence of clay (montmorillonite) significantly increased yields in the reactions of dipeptides but it did not have much effect on the reactions of oligopeptides. However, an opposite effect of clay, protection of poly(Gly)n against decomposition, was proven. Copyright © 2004 European Peptide Society and John Wiley & Sons, Ltd.
Polymer‐bound alkyltriazenes for mild racemization‐free esterification of amino acid and peptide derivatives
Authors: Smerdka Joachim , Rademann Jörg , Jung Günther 
Published: June 2004

AbstractA novel tool for polymer‐assisted solution phase (PASP) esterification of amino acid and peptide derivatives has been developed. When treated with carboxylic acids, polymer‐bound alkyltriazenes react with a loss of nitrogen and transfer of the alkyl moiety to the carboxylate anion to form the corresponding alkyl esters. There are no limitations with regard to either the protecting groups or the nature of the amino acid. Furthermore no racemization occurs at the chiral centers of the amino acids as demonstrated by chiral GC‐MS analyses. Alkyltriazene‐resins were also applied successfully to the esterification of peptide acids and other peptidic structures, such as tripalmitoyl‐S‐glyceryl‐cysteine (Pam3Cys). The triazene‐mediated esterification reaction is exceptionally mild, and there is no need for prior activation of the carboxy groups. This method is therefore particularly suitable for the alkylation of complex peptidomimetic structures prone to racemization and for acid‐sensitive structures. Copyright © 2004 European Peptide Society and John Wiley & Sons, Ltd.