bluuebunny/crossref_metadata_2025 huggingface dataset:
Misuse of corticosteroids in some of the drugs dispensed as preparations from alternative systems of medicine in India
Authors: Gupta S. K. , Kaleekal T. , Joshi S.
Published: September 2002

Screening for corticosteroids carried out on 120 samples of alternative medicines which were dispensed to patients suffering mainly from asthma, arthritis, etc., showed that 38.32% of them were adulterated with steroids. Most of these samples were submitted for screening by either a medical practitioner or the patients themselves, who suspected effects of steroids from these drugs. The percentage of steroid positivity was determined in ayurvedic drugs, homeopathic drugs, and unknown or other category of drugs. The presence of steroids in these drugs given for different ailments such as asthma, arthritis, and unknown/other ailments was also tabulated. The results show that a high percentage of these samples contained corticosteroids, however, the distribution of positivity amongst groups was not statistically significant. The lack of proper quality control mechanisms to verify ingredients or efficacy of ‘alternative medicines’ has led to the proliferation of the practice of dispensing spurious drugs containing corticosteroids as alternative medicines. This study aims to highlight the existence of ‘quick fix’ remedies dispensed as ‘alternative medicines’ which not only cause extensive adverse health effects to the patients but also bring alternative systems of medicines into disrepute. The deliberate contamination of corticosteroids with alternative systems of medicine by some practitioners is a cause of great concern. Such practices may not only disgrace alternative systems of medicine but may also lead to adverse side‐effects on chronic exposure. Copyright © 2000 John Wiley & Sons, Ltd.
Interactions between poly(acrylamide)–poly(itaconic acid) and cerium(IV)–nitrilotriacetic acid redox pair in the synthesis of acrylamide and itaconic acid homo‐ and copolymers
Authors: Erbil Candan , Uyanık Nurseli
Published: September 2002

Homopolymers of itaconic acid (PIA) and its copolymers with acrylamide (P(IA‐AAm) were synthesized using ceric ammonium nitrate (NH4)2Ce(NO3)6 in combination with nitrilotriacetic acid (NTA) as redox initiator, and potassium persulphate at pH 1. The chain structures of the resulting products have been studied by FTIR spectroscopy. It is concluded from a comparison of spectroscopic results with gravimetric and viscometric data that the depressions in the yields and viscosity numbers in the case of Ce(IV)–NTA redox pair result from interactions between the constituents of the redox initiator and IA. Spectra of the insoluble and pale yellow precipitates, which are formed during the first 4 h of the reaction, after addition of Ce(IV) solution to the NTA and NTA–IA homogeneous solutions, also indicate the presence of various oxidation products.

Furthermore, it is observed that H‐bonded homopolymer complex obtained from PAAm–PIA blends, prepared from aqueous solutions containing equal unit moles of each polymer, contain both ordered and defective structures.

© 2001 Society of Chemical Industry
Modelling of resol resin polymerization with various formaldehyde/phenol molar ratios
Authors: Manfredi Liliana B , Riccardi Carmen C , Osa Orlando de la , Vázquez Analía
Published: September 2002

The kinetics of polymerization of phenol and formaldehyde are modelled to account for the formation of resol resin with various initial formaldehyde/phenol molar ratios. The conversion of phenol and formaldehyde is used to determine the equilibrium constants for phenolate ion and methylene glycol. The relative concentration of each compound is obtained as a function of time. The molecular weight is also determined for each resol resin at the end of the reaction. The evaluation of substituted phenols, hydroxymethylol phenols and methylene bridges was carried out by infrared spectroscopy. The experimental tendencies are in agreement with the results of the model.

© 2001 Society of Chemical Industry
Effects of radiation pretreatments on the rubber adsorption power and reinforcing properties of fillers in rubber compounds
Authors: Cataldo Franco
Published: September 2002

Radiation damage to fillers such as carbon black, graphite and silica induced by high doses of γ‐radiation or neutrons dramatically increases their ability to adsorb rubber irreversibly. In fact, the ‘bound rubber’, ie the amount of non‐extractable rubber which remains irreversibly linked to the filler matrix, increases dramatically in radiation‐treated fillers. The increased adsorption power of radiation‐damaged fillers has been attributed to the formation of a higher concentration of surface defects in the form of trapped free radicals, fullerene‐like structures and other kinds of defects.

The mechanical properties of rubber compounds filled with radiation‐treated carbon blacks show a significant increase in their reinforcing effects, in line with the increased ability to form ‘bound rubber’.

© 2001 Society of Chemical Industry
Photovoltaics literature survey (no. 6)
Authors: Keevers Mark J.
Published: September 2002

In order to help keep readers up‐to‐date in the field each issue of Progress in Photovoltaics will contain a list of recently published journal articles most relevant to its aims and scope. This list is drawn primarily from recent issues of IEEE Transactions on Electron Devices, Journal of Applied Physics, Progress in Photovoltaics, Solar Energy and Solar Energy Materials and Solar Cells, with additional journals surveyed if space permits. To assist the reader, the list is separated into broad categories, but please note that these classifications are by no means strict. Also note that inclusion in the list is not an endorsement of a paper's quality. If you have any suggestions please email Mark Keevers at m.keevers@unsw.edu.au Copyright © 2001 John Wiley & Sons, Ltd.
Optimisation of an asymmetric static concentrator: the PEC‐44D
Authors: Zanesco I. , Lorenzo E.
Published: September 2002

In this paper, the optimisation of the PV static concentrator module PEC‐44D for constant demand during the year is presented. The method used is based on simulation of the system performance during 10 years and the set of concentrator parameters that produces the lowest cost of the PV array is determined. We find that the optimised PEC‐44D module can be 38% cheaper than a standard module. Experimental results were obtained for a prototype of the optimised PEC‐44D to validate the theoretical analysis of the behaviour of the concentrator. We conclude that the daily irradiation measured on the cells correlates well with calculated values, and that the operating temperature of the bifacial cells in this static concentrator is slightly lower than that of the monofacial cells in a standard module. Copyright © 2002 John Wiley & Sons, Ltd.
The impurity photovoltaic (IPV) effect in wide‐bandgap semiconductors: an opportunity for very‐high‐efficiency solar cells?
Authors: Beaucarne G. , Brown A. S. , Keevers M. J. , Corkish R. , Green M. A.
Published: September 2002

Following recent progress in the study of limiting efficiencies of photovoltaic devices with multiple energy levels, we suggest using the impurity photovoltaic (IPV) effect in wide‐bandgap semiconductors as a means to achieve very‐high‐efficiency solar cells. We discuss the requirements for a high‐efficiency IPV device and review some of the material systems that could be used. As a case study, we investigate theoretically β‐SiC IPV solar cells with a model based on a modified Shockley–Read–Hall theory. The high‐efficiency potential is confirmed and the important issues for implementation are presented and discussed. Copyright © 2002 John Wiley &; Sons, Ltd.
Role of grafting in the emulsion polymerization of vinyl acetate with poly(vinyl alcohol) as an emulsifier. I. Effect of the degree of blockiness on the kinetics and mechanism of grafting
Authors: Budhlall B. M. , Sudol E. D. , Dimonie V. L. , Klein A. , El‐Aasser M. S.
Published: September 2002

The role of grafting in particle nucleation during the emulsion polymerization of vinyl acetate with partially hydrolyzed poly(vinyl alcohol) (PVA) as an emulsifier and potassium persulfate as an initiator was investigated. The polymerizations were carried out in batch with a low solids (10%) recipe. An automated reaction calorimeter (Mettler RC1) was used for the direct monitoring of the kinetics of emulsion polymerizations with three medium molecular weight PVAs differing in their degrees of blockiness (Poval 217EE > 217E > 217). Smith–Ewart case 1 kinetics (average number of free radicals per particle < 0.5) were followed in all cases, and no constant rate in interval II was observed. Contrary to what was expected, a nonlinear relationship was observed between the rate of polymerization (Rp) and the number of particles (Np). At Rp max, Np (217E) > Np (217EE) > Np (217), and the final Np was independent of the degree of blockiness of PVA. The particle size distributions were broad (particle diameter = 20–100 nm) and bimodal. On the basis of these data, we concluded that particle nucleation was continuous and was accompanied by extensive limited aggregation during the particle growth stages. The evolution of the amounts of grafted PVA and poly(vinyl acetate) (PVAc) were determined in polymerizations employing the two PVAs differing the most in blockiness (Poval 217EE and 217). The grafted PVAc followed similar profiles, increasing with conversion, particularly near the end of the two reactions. The amounts of grafted PVAc were about the same in the final latexes (37–39%). In contrast, the grafting of PVA was nearly complete by the time monomer droplets had disappeared in each reaction (25% conversion). However, the extent of grafting differed significantly, with the blockier PVA having about one‐third the grafting of the more random PVA (∼10% vs ∼30%). In these low solids recipes, grafting appeared to be primarily a solution event, occurring predominantly in the aqueous phase and not at the particle/water interface, as was previously speculated. The PVAc grafts grew until the molecules became water‐insoluble and precipitated, forming polymer particles. © 2001 John Wiley & Sons, Inc. J Polym Sci Part A: Polym Chem 39: 3633–3654, 2001
Synthesis and characterization of water‐soluble barbiturate‐ and thiobarbiturate‐functionalized polystyrene
Authors: Raja S. , Dhamodharan R.
Published: September 2002

The synthesis and characterization of barbiturate‐ and thiobarbiturate‐functionalized polystyrene from polystyrene homopolymer by polymer‐modification reactions is discussed. Polystyrene homopolymer quantitatively functionalized at the para postion with diethyl oxomalonate functionality was subjected to a condensation reaction with urea and thiourea in the presence of sodium methoxide in methanol. This reaction proceeded essentially to quantitative conversion to the barbiturate‐ (BAPS) and thiobarbiturate‐functionalized polystyrenes (TBAPS) as estimated by 1H NMR, UV, and IR spectroscopies. Thus, several copolymers of styrene with barbiturate‐ and thiobarbiturate‐functionalized styrene were synthesized. The detailed characterizations of quantitatively functionalized polystyrene using gel permeation chromatographic, IR, UV, and 1H NMR spectroscopic techniques as well as thermogravimetric analysis are discussed. An application of the newly synthesized polymer in removing Cu(II) ions from aqueous solution is demonstrated. This is the first report on the synthesis of BAPS and TBAPS by the polymer‐modification route or otherwise. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 40: 731–737, 2002; DOI 10.1002/pola.10154
Poly(3,4‐ethylenedioxythiophene)‐based copolymers for biosensor applications
Authors: Kros Alexander , Nolte Roeland J. M. , Sommerdijk Nico A. J. M.
Published: September 2002

The synthesis of 3,4‐ethylenedioxythiophene (EDOT) derivatives bearing functional groups is described. Their electrochemical characteristics were investigated with cyclic voltammetry and ultraviolet–visible spectroscopy. Various copolymers of EDOT and modified EDOT containing hydroxyl groups were electrochemically prepared. The ability to bind proteins to the surface of these copolymers was investigated through the covalent coupling of glucose oxidase. The obtained materials were used as working electrodes and were shown to be able to amperometrically detect glucose under aerobic and anaerobic conditions. Possible applications of these materials as biosensors are discussed. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 40: 738–747, 2002; DOI 10.1002/pola.10159
Modeling of photobleaching for the photoinitiation of thick polymerization systems
Authors: Miller G. A. , Gou L. , Narayanan V. , Scranton A. B.
Published: September 2002

We present a mathematical description of the spatial and temporal evolution of the light intensity gradient, initiator concentration gradient, and initiation rate profiles for photobleaching initiator systems. This article builds on the foundation provided by previous researchers' contributions by generalizing the governing differential equations to include the effects of absorption by the initiator fragments, absorption by the monomer, and diffusion of the initiator. Simulation results have confirmed that, at any given time, the initiation rate profile resembles a wave front that propagates through the sample. The simulation results suggest that there is an optimum initiator concentration for efficient photopolymerization of thick samples. As either the initiator concentration or molar absorptivity is increased, the initiation rate at the peak of the wave front increases, the breadth of the propagating front decreases, and the rate of spatial propagation through the sample decreases. In contrast, the maximum photoinitiation rate and rate of spatial propagation of the initiation front can be simultaneously increased with an increasing initiator quantum yield or a decreasing absorptivity of the monomer or photolysis products. Finally, on the basis of these studies, diffusion is expected to have negligible effects in most photobleaching systems. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 40: 793–808, 2002; DOI 10.1002/pola.10162
Synthesis and reaction of β‐hydroxyaspartic acid‐based polymethacrylate
Authors: Sanda Fumio , Yokoi Makiko , Kudo Hiroto , Endo Takeshi
Published: September 2002

O‐Methacryloyl‐N‐(tert‐butoxycarbonyl)‐β‐hydroxyaspartic acid dimethyl ester was synthesized by methyl esterification of β‐hydroxyaspartic acid, followed by protection of the amino group with the tert‐butoxycarbonyl group and then the reaction of the hydroxyl group with methacryloyl chloride. The monomer efficiently underwent radical polymerization to afford the corresponding polymer with a number‐average molecular weight of 42,000 in good yields. The alkaline hydrolysis of the polymer occurred not only at the methyl ester but also at the ester moiety between the main and side chains of the polymer. The methyl ester‐free polymer gradually released β‐hydroxyaspartic acid moiety in a phosphate buffer solution with pH = 7.3 and 7.8. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 40: 2782–2788, 2002
Homopolymerizations and random copolymerizations of olefins with amino‐substituted cyclopentadienylchromium complexes
Authors: Ogata Keiji , Nakayama Yuushou , Yasuda Hajime
Published: September 2002

1‐(2‐N,N‐Dimethylaminoethyl)‐2,3,4,5‐tetramethylcyclopentadienyl‐chromium dichloride (1), (2‐N,N‐dimethylaminoethyl)cyclopentadienylchromium dichloride (6), and (2‐N,N‐dimethylaminoethyl)indenylchromium dichloride (7) in the presence of modified methylaluminoxane exhibit high catalytic activities for the polymerization of ethylene with random copolymerizations of ethylene with propylene, ethylene with 1‐hexene, and propylene with 1‐hexene. These initiators conduct polymerizations to give high molecular weight polymers with low polydispersities. However, the stereoregularities are very poor in these reactions. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 40: 2759–2771, 2002
Emulsion polymerization of styrene using polystyrene‐block‐poly(ethylene oxide) macromonomers as stabilizers
Authors: Gibanel Sébastien , Heroguez Valérie , Forcada Jacqueline
Published: September 2002

New diblock macromonomers were used as reactive emulsifiers in the emulsion polymerization of styrene. The nature of the reactive group, the molecular weight, the length of the poly(ethylene oxide) (PEO) block, and the molecular structure of the macromonomer were systematically investigated during this process by analyzing the evolution of the conversion and particle diameters. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 40: 2819–2827, 2002
Structure and morphology of the aliphatic polyester poly(δ‐valerolactone) in solution‐grown, chain‐folded lamellar crystals
Authors: Furuhashi Yukiko , Sikorski Pawel , Atkins Edward , Iwata Tadahisa , Doi Yoshiharu
Published: September 2002

Poly(δ‐valerolactone) (PVL) crystals in the form of chain‐folded lamellae were prepared by isothermal crystallization from a 2‐methylbutane‐2‐ol solution. Wide‐angle and small‐angle X‐ray diffraction data, obtained from PVL lamellae sedimented to form oriented mats, were supplemented with morphological and structural data from electron microscopy, both imaging and diffraction. The diffraction signals index on an orthorhombic unit cell with the parameters a = 0.747 ± 0.002 nm, b = 0.502 ± 0.002 nm, and c (chain axis) = 0.742 ± 0.002 nm. Similar unit cell parameters were obtained from crystals grown from 1‐octanol and also from drawn melt‐pressed films. The evidence supports a model containing two antiparallel chain segments in the unit cell. The c value of 0.742 nm is appropriate for an all‐trans or onefold helical backbone conformation for the straight stems. Possible slight perturbations at the ester units from the all‐trans backbone conformation are discussed. Computerized modeling was used to optimize the adjacent‐reentry folded structure. The setting angles, with respect to the a axis, are ±58° for the corner and center chains. The lamellae are 7.26 ± 0.05 nm thick, and the chains run orthogonal to the lamellar surface. The chains fold in the diagonal (110) and (11¯0) planes in an alternating fashion. The X‐ray diffraction data suggest that a proportion of adjacent paired antiparallel entities, or hairpin units, are c‐axis‐sheared, and a relationship to the results obtained from drawn films is discussed. A brief comparison is also made with related polymer structures. © 2001 John Wiley & Sons, Inc. J Polym Sci Part B: Polym Phys 39: 2622–2634, 2001
Free‐energy model of asymmetry in side‐chain liquid‐crystalline diblock copolymers
Authors: Anthamatten Mitchell , Hammond Paula T.
Published: September 2002

Side‐chain liquid‐crystalline‐b‐amorphous copolymers combine the thermotropic ordering of liquid crystals (LCs) with the physics of block copolymer phase segregation. In our earlier experiments, we observed that block copolymer order–order and order–disorder transitions could be induced by LC transitions. Here we report the development of a free‐energy model to understand the interplay between LC ordering and block copolymer morphology in an incompressible melt. The model considers the interaction between LC moieties, the stretching of amorphous chains from curved interfaces, interfacial surface contributions, and elastic deformation of the nematic phase. The LC block is modeled with Wang and Warner's theory, in which nematogens interact through mean‐field potentials, and the LC backbone is modeled as a wormlike chain. Free energy is estimated for various morphologies: homogeneous, lamellar, cylinder micelle, and spherical micelle. Phase diagrams were constructed by iteration over temperature and composition ranges. The resulting composition diagrams are highly asymmetric, and a variety of first‐order transitions are predicted to occur at the LC clearing temperature. Qualitatively, nematic deformation energies destabilize curved morphologies, especially when the LC block is in the center of the block copolymer micelle. The thermodynamics of diblocks with laterally attached, side‐on mesogens are also explored. Discussion focuses on how well the model captures experimental phenomena and how the predicted phase boundaries are affected by changes in polymer architecture. © 2001 John Wiley & Sons, Inc. J Polym Sci Part B: Polym Phys 39: 2671–2691, 2001
From structure to function: YrbI from Haemophilus influenzae (HI1679) is a phosphatase
Authors: Parsons James F. , Lim Kap , Tempczyk Aleksandra , Krajewski Wojiech , Eisenstein Edward , Herzberg Osnat
Published: September 2002

The crystal structure of the YrbI protein from Haemophilus influenzae (HI1679) was determined at a 1.67‐Å resolution. The function of the protein had not been assigned previously, and it is annotated as hypothetical in sequence databases. The protein exhibits the α/β‐hydrolase fold (also termed the Rossmann fold) and resembles most closely the fold of the L‐2‐haloacid dehalogenase (HAD) superfamily. Following this observation, a detailed sequence analysis revealed remote homology to two members of the HAD superfamily, the P‐domain of Ca2+ ATPase and phosphoserine phosphatase. The 19‐kDa chains of HI1679 form a tetramer both in solution and in the crystalline form. The four monomers are arranged in a ring such that four β‐hairpin loops, each inserted after the first β‐strand of the core α/β‐fold, form an eight‐stranded barrel at the center of the assembly. Four active sites are located at the subunit interfaces. Each active site is occupied by a cobalt ion, a metal used for crystallization. The cobalt is octahedrally coordinated to two aspartate side‐chains, a backbone oxygen, and three solvent molecules, indicating that the physiological metal may be magnesium. HI1679 hydrolyzes a number of phosphates, including 6‐phosphogluconate and phosphotyrosine, suggesting that it functions as a phosphatase in vivo. The physiological substrate is yet to be identified; however the location of the gene on the yrb operon suggests involvement in sugar metabolism. Proteins 2002;46:393–404. © 2002 Wiley‐Liss, Inc.
Structure of bovine α‐1,3‐galactosyltransferase and its complexes with UDP and DPGal inferred from molecular modeling
Authors: Rao Mohan , Tvaroska Igor
Published: September 2002

A homology model of α‐1,3‐galactosyltransferase (α‐1,3‐GalT), the retaining enzyme responsible for the formation of α‐galactosyl epitopes, has been developed by means of molecular modeling using the SpsA glycosyltransferase structure. A protein‐ligand docking approach was used to model α‐1,3‐GalT complexed with UDP and UDP‐Gal. The comparison of structural features found in the α‐1,3‐GalT homology model with available structural data on this class of enzymes revealed similarities in the UDP‐binding pocket. In the predicted structure of the complexes, the pyrophosphate interacts with the DVD motif (Asp‐225, Val‐226, and Asp‐227) of α‐1,3‐GalT through the Mn2+ cation. The uridine part of the UDP binds into the well‐defined cavity that consists of Phe‐134, Tyr‐139, Ile‐140, Val‐136, Arg‐194, Arg‐202, Lys‐209, Asp‐173, His‐218, and Thr‐137 in a conformation that is generally observed in the crystal structures of other glycosyltransferase complexes. Proteins 2001;44:428–434. © 2001 Wiley‐Liss, Inc.
Quantum mechanics simulation of protein dynamics on long timescale
Authors: Liu Haiyan , Elstner Marcus , Kaxiras Efthimios , Frauenheim Thomas , Hermans Jan , Yang Weitao
Published: September 2002

Protein structure and dynamics are the keys to a wide range of problems in biology. In principle, both can be fully understood by using quantum mechanics as the ultimate tool to unveil the molecular interactions involved. Indeed, quantum mechanics of atoms and molecules have come to play a central role in chemistry and physics. In practice, however, direct application of quantum mechanics to protein systems has been prohibited by the large molecular size of proteins. As a consequence, there is no general quantum mechanical treatment that not only exceeds the accuracy of state‐of‐the‐art empirical models for proteins but also maintains the efficiency needed for extensive sampling in the conformational space, a requirement mandated by the complexity of protein systems. Here we show that, given recent developments in methods, a general quantum mechanical‐based treatment can be constructed. We report a molecular dynamics simulation of a protein, crambin, in solution for 350 ps in which we combine a semiempirical quantum‐mechanical description of the entire protein with a description of the surrounding solvent, and solvent‐protein interactions based on a molecular mechanics force field. Comparison with a recent very high‐resolution crystal structure of crambin (Jelsch et al., Proc Natl Acad Sci USA 2000;102:2246–2251) shows that geometrical detail is better reproduced in this simulation than when several alternate molecular mechanics force fields are used to describe the entire system of protein and solvent, even though the structure is no less flexible. Individual atomic charges deviate in both directions from “canonical” values, and some charge transfer is found between the N and C‐termini. The capability of simulating protein dynamics on and beyond the few hundred ps timescale with a demonstrably accurate quantum mechanical model will bring new opportunities to extend our understanding of a range of basic processes in biology such as molecular recognition and enzyme catalysis. Proteins 2001;44:484–489. © 2001 Wiley‐Liss, Inc.
Folding and stability of the three‐stranded β‐sheet peptide Betanova: Insights from molecular dynamics simulations
Authors: Colombo Giorgio , Roccatano Danilo , Mark Alan E.
Published: September 2002

The dynamics of the three‐stranded β‐sheet peptide Betanova has been studied at four different temperatures (280, 300, 350, and 450 K by molecular dynamics simulation techniques, in explicit water. Two 20‐ns simulations at 280 K indicate that the peptide remains very flexible under “folding” conditions sampling a range of conformations that together satisfy the nuclear magnetic resonance (NMR)‐derived experimental constraints. Two simulations at 300 K (above the experimental folding temperature) of 20 ns each show partial formation of “native”‐like structure, which also satisfies most of the NOE constraints at 280 K. At higher temperature, the presence of compact states, in which a series of hydrophobic contacts remain present, are observed. This is consistent with experimental observations regarding the role of hydrophobic contacts in determining the peptide's stability and in initiating the formation of turns and loops. A set of different structures is shown to satisfy NMR‐derived distance restraints and a possible mechanism for the folding of the peptide into the NMR‐determined structure is proposed. Proteins 2002;46:380–392. © 2002 Wiley‐Liss, Inc.
Bound xenobiotic residues in food commodities of plant and animal origin
Authors: Skidmore M W , Paulson G D , Kuiper H A , Ohlin B , Reynolds S
Published: September 2002

The following are extended summaries of Technical Reports which are produced at intervals by the International Union of Pure and Applied Chemistry (IUPAC). They are entirely the responsibility of IUPAC/the authors and do not necessarily reflect the views of the Editorial Board of Pest Management Science.

Copyright © 2002 Society of Chemical Industry
The effects of phytochemical pesticides on the growth of cultured invertebrate and vertebrate cells
Authors: Salehzadeh Areaf , Jabbar Abdul , Jennens Lynn , Ley Steven V , Annadurai Ramasamy S , Adams Roger , Strang Robin H C
Published: September 2002

A range of cultured cells of invertebrate and vertebrate origin was grown in the presence of a number of phytochemical pesticides to test the effect of the latter on cell proliferation. The main observation was that azadirachtin was a potent inhibitor of insect cell replication, with an EC50 of 1.5 × 10−10 M against Spodoptera cells and of 6.3 × 10−9 M against Aedes albopictus cells, whilst affecting mammalian cells only at high concentrations (>10−4 M). As expected, the other phytochemical pesticides, except for rotenone, had little effect on the growth of the cultured cells. Rotenone was highly effective in inhibiting the growth of insect cells (EC50:10−8 M) but slightly less toxic towards mammalian cells (EC50:2 × 10−7 M). Neem terpenoids other than azadirachtin and those very similar in structure significantly inhibited growth of the cell cultures, but to a lesser degree. The major neem seed terpenoids, nimbin and salannin, for example, inhibited insect cell growth by 23% and 15%, respectively.

© 2002 Society of Chemical Industry
Aerosolized essential oils and individual natural product compounds as brown treesnake repellents
Authors: Clark Larry , Shivik John
Published: September 2002

Chemical irritants useful as repellents for brown treesnakes (Boiga irregularis) were identified. Exposure to various compounds produced a range of intensities for locomotory behavior in snakes. Essential oils comprised of 10 g liter−1 solutions of cedarwood, cinnamon, sage, juniper berry, lavender and rosemary each were potent snake irritants. Brown treesnakes exposed to a 2‐s burst of aerosol of these oils exhibited prolonged, violent undirected locomotory behavior. In contrast, exposure to a 10 g liter−1 concentration of ginger oil aerosol caused snakes to locomote, but in a deliberate, directed manner. We also tested specific compounds, all derivative of food and flavor ingredients. 10 g liter−1 solutions delivered as aerosols of m‐anisaldehyde, trans‐anethole, cineole, cinnamaldehyde, citral, ethyl phenylacetate, eugenol, geranyl acetate or methyl salicylate all acted as potent irritants for brown treesnakes. The individual ingredients were classified using cluster analysis into groups that promoted different levels of response by snakes. This study is the first to systematically investigate the irritant potential of natural products for snakes. These data will be useful in the development of practical pest management tools for snakes.

Published in 2002 for SCI by John Wiley & Sons, Ltd.
Group effects on insecticide toxicity in workers of the Formosan subterranean termite, Coptotermes formosanus Shiraki
Authors: Valles Steven M , Woodson W David
Published: September 2002

Coptotermes formosanus workers were treated topically with insecticide and subsequently held individually or in groups to examine possible effects on insecticide toxicity. Chlorpyrifos, cypermethrin and chlordane toxicities were 1.4‐, 1.5‐, and 1.3‐fold greater, respectively, among workers held in groups compared with those held individually after insecticide treatment. Experiments were conducted to examine how enhanced toxicity occurred among termites held in groups after topical insecticide treatment. When workers were treated topically with chlordane and immediately placed with untreated workers, significantly greater numbers of untreated workers were killed compared with controls at all ratios examined (insecticide‐treated:untreated). These data indicated that workers treated topically with insecticide were capable of somehow transferring a lethal dose of insecticide to untreated workers confined in the vial. Chlordane was recovered from untreated workers which had been confined with chlordane‐treated workers; significantly higher quantities of chlordane were recovered from dead workers exposed to chlordane‐treated workers compared with surviving workers exposed to chlordane‐treated workers. Possible mechanisms of insecticide transfer from insecticide‐treated to untreated termites are discussed.

Published in 2002 for SCI by John Wiley & Sons, Ltd.
Location of Disulfide bonds in mature α‐L;‐fucosidase from pea
Authors: Codina Anna , Vilaseca Marta , Tarragó Teresa , Fernández Irene , Ludevid Dolors , Giralt Ernest
Published: September 2002

Fuc‐9 is the mature form of a vacuolar α‐L;‐fucosidase enzyme which seems to play an important role in plant growth regulation. Fuc‐9 is a 202‐residue protein containing five Cys residues located at positions 64, 109, 127, 162 and 169. In this study, the disulfide structure of Fuc‐9 was determined by MALDI‐TOF mass spectrometry (MS), with minimal clean‐up of the samples and at a nanomolar scale. Two strategies, based on a specific chemical cleavage (with 2‐nitro‐5‐thiocyanobenzoic acid and alkaline conditions) at the Cys residues and modification of Cys residues by acrylamide/deuterium labeled acrylamide alkylation, were used. Using these methods, the disulfide pairings Cys64‐Cys109 and Cys162‐Cys169 could be established. The advantages and limitations of our experimental approach are discussed. Copyright © 2001 European Peptide Society and John Wiley & Sons, Ltd.
Conformation of the tripeptide Cbz‐Pro‐Leu‐Trp‐OBzl(CF3)2 deduced from two‐dimensional 1H‐NMR and conformational energy calculations is related to its affinity for NK1‐receptor
Authors: Millet Régis , Goossens Laurence , Goossens Jean‐François , Chavatte Philippe , Bertrand‐Caumont Karine , Houssin Raymond , Hénichart Jean‐Pierre
Published: September 2002

Chemical modifications of dual NK1/NK2 ligand Cbz‐Gly‐Leu‐Trp‐OBzl(CF3)2 (1) enabled us to create a high NK1 selective ligand Cbz‐Pro‐Leu‐Trp‐OBzl(CF3)2 (2). A determination of the conformational behavior of tripeptide 2 in solution is described. The 1D and 2D 1H‐NMR techniques (COSY and ROESY) were used to assign resonances. Observed interproton distance restraints were considered to characterize conformational behavior. Spectral data indicate that tripeptide 2 presents a rigidified structure in DMSO stabilized by H‐bond in two γ‐turns. Agreement with experimental data was obtained by averaging the 1H‐NMR parameters over several combinations of low‐energy conformations. Copyright © 2001 European Peptide Society and John Wiley & Sons, Ltd.
Conformational solution studies of [Sar7]desamino‐ and [MeAla7]desamino‐ vasopressin analogues using NMR spectroscopy
Authors: Rodziewicz‐Motowidło Sylwia , Zhukov Igor , Kasprzykowski Franciszek , Grzonka Zbigniew , Ciarkowski Jerzy , Wójcik Jacek
Published: September 2002

Solution structures of two analogues of vasopressin with an amino acid sequence of c[Mpa1‐Tyr2‐Phe3‐Gln4‐Asn5‐Cys6]‐Xaa7‐Arg8‐Gly9‐NH2 (Xaa = Sar [I] or MeAla [II]) were established using ROE and the 3JHNHα couplings. Each of the peptides was found to exist in two stable isomers, pertaining to the cis or trans status of the Cys6‐Xaa7 peptide bond, thus giving rise to four study objects.

Two methods for studies of the conformational properties of the structures were compared. In the first, the algorithm consisted of three steps: (i) An Electrostatically Driven Monte‐Carlo (EDMC) search for low‐energy conformations. (ii) Simulations of the NOESY spectra and the vicinal couplings for these conformations. (iii) Determination of the statistical weights of the conformations with the ANALYZE package, so as to meet the best fit of the averaged NOE intensities and couplings to the experimental data. In the second method, the distance constraints and the torsion angles were used as the usual constraints in the Distance Geometry and Simulated Annealing algorithms. The flexibility of the pressin ring and the C‐terminus was characterized by a large number of families of conformations. The presence of the β‐turn at position 4,5 was confirmed for all low energy structures found. The use of the EDMC method for the elaboration of the NMR data for small flexible peptides yielded an adequate description of their conformational diversity and is the method of choice for the analysis of their solution structures. Copyright © 2002 European Peptide Society and John Wiley & Sons, Ltd.
The terminology of guanidine formation
Authors: Jones John H
Published: September 2002

The terminology in recent use for the conversion NH2 to NHC(NH)NH2 is surveyed and shown to be in a state of extreme confusion: a pragmatic recommendation is made that the word guanidinylation should be generally adopted for this conversion. Copyright © 2002 European Peptide Society and John Wiley & Sons, Ltd.
New potent hGH‐RH analogues with increased resistance to enzymatic degradation
Authors: Izdebski Jan , Witkowska Ewa , Kunce Danuta , Orłowska Alicja , Baranowska Bogusława , Radzikowska Małgorzata , Smoluch Marek
Published: September 2002

Four hGH‐RH analogues containing homoarginine (Har) and/or D‐Arg were obtained by solid‐phase methodology using Boc‐chemistry. To introduce Har residues, a Lys(Fmoc) protected Lys derivative was incorporated in the appropriate positions (11, 12, 20, 21 or 29); after assembly of the peptide chain the Fmoc group was removed and the peptide‐resin was guanidinylated by treatment with N, N′‐bis(tert‐butoxycarbonyl)‐S‐methylisothiourea. The peptides were cleaved from the resin by treatment with liquid HF, and the products were purified by RP‐HPLC. The peptides were subjected to digestion by trypsin, and the course of the reaction was followed by HPLC and ESI‐MS. It was found that peptide bonds formed by the carboxyl group of Har are completely stable to trypsin. The course of cleavage at Lys or Arg residues depends on the position of Har in the sequence. All the analogues investigated stimulate the release of GH in rats after subcutaneous administration, and were about 50–100 times as potent as rGH‐RH itself. The analogues had no effect on PRL, LH and FSH levels. Copyright © 2002 European Peptide Society and John Wiley & Sons, Ltd.
Reliability demonstration test for a finite population
Authors: Lu Ming‐Wei , Rudy Richard J.
Published: September 2002

In many situations, we want to accept or reject a population with small or finite population size. In this paper, we will describe Bayesian and non‐Bayesian approaches for the reliability demonstration test based on the samples from a finite population. The Bayesian method is an approach that combines prior experience with newer test data in the application of statistical tools for reliability quantification. When test time and/or sample quantity is limited, the Bayesian approach should be considered. In this paper, a non‐Bayesian reliability demonstration test is considered for both finite and large population cases. The Bayesian approach with ‘uniform’ prior distributions, Polya prior distributions, and sequential sampling is also presented. Copyright © 2001 John Wiley & Sons, Ltd.
Statistically constrained economic design of the multivariate exponentially weighted moving average control chart
Authors: Molnau Wade E. , Montgomery Douglas C. , Runger George C.
Published: September 2002

This paper shows that economic statistical design can provide for better statistical properties without significantly increasing optimal total costs. Cost comparisons between optimal economic statistical designs and optimal economic designs show no significant cost increases. The average run length (ARL) constraints added by economic statistical design significantly improve the statistical properties of the control chart scheme. False alarm frequency is limited while keeping good shift detection characteristics. In addition, the Multivariate Exponentially Weighted Moving Average (MEWMA) control schemes performed better from the cost standpoint than the benchmark pure statistical design—the Hotelling T2 control chart. This improvement held for unconstrained and constrained designs. Finally, cost comparisons at small values of n showed significant advantage for the MEWMA schemes. Copyright © 2001 John Wiley & Sons, Ltd.
Estimation of the expected ROCOF of a repairable system with bootstrap confidence region
Authors: Phillips M. J.
Published: September 2002

Bootstrap methods are presented for constructing confidence regions for the expected ROCOF of a repairable system. This is based on the work of Cowlinget al.(Journal of the American Statistical Association1996;91: 1516–1524) for the intensity function of a NHPP. The method is applied to the failure times of a photocopier given by Baker (Technometrics1996;38: 256–265). Copyright © 2001 John Wiley & Sons, Ltd.
Assessing the maintenance in a process using a semi‐parametric approach
Authors: Ansell Jake , Archibald Tom , Dagpunar John , Thomas Lyn , Abell Peter , Duncalf David
Published: September 2002

In developing any successful maintenance strategy it is important to be able to estimate the rate of occurrence of maintenance events. In a previous paper the authors have argued that there are advantages to using a non‐parametric or semi‐parametric approach to such analysis. In this paper the authors explore the use of the approach to data from the water industry using a case study. The approach provides insight into the context revealing the impact of maintenance on the process. The effect of the maintenance strategy can be evaluated. The paper explores the practical issues of missing values and implementation of an appropriate maintenance strategy. Copyright © 2001 John Wiley & Sons, Ltd.
Bayesian belief nets for managing expert judgement and modelling reliability
Authors: Sigurdsson J. H. , Walls L. A. , Quigley J. L.
Published: September 2002

Bayesian belief nets (BBNs) provide an effective way of reasoning under uncertainty. They have a firm mathematical background in probability theory and have been used in a variety of application areas, including reliability. BBNs can provide alternative representations of fault trees and reliability block diagrams. BBNs can be used to incorporate expert judgement formally into the modelling process. It has been claimed BBNs may overcome some of the limitations of standard reliability techniques. This paper presents an overview of BBNs and illustrates their use through a simple tutorial on system reliability modelling. The use of BBNs in reliability to date is reviewed. The challenge of using BBNs in reliability practice is explored and areas of research are identified. Copyright © 2001 John Wiley & Sons, Ltd.
Characterisation and determination of indole alkaloids in frog‐skin secretions by electrospray ionisation ion trap mass spectrometry
Authors: McClean Stephen , Robinson Robert C. , Shaw Chris , Smyth W. Franklin
Published: September 2002

The characterisation of selected indole alkaloids in a quadrupole ion trap mass spectrometer is presented. Fragmentation profiles for tryptamine, 5‐hydroxytryptamine (5‐HT), N′‐methyl 5‐hydroxytryptamine (N′‐methyl 5‐HT), N′,N′‐dimethyl 5‐hydroxytryptamine (bufotenine), N′,N′,N′‐trimethyl 5‐hydroxytryptamine (5‐HTQ), and N′,N′‐dimethyl 5‐methoxytryptamine (5‐MeODMT) are presented with proposed structures given for each product ion observed. Such MSn experiments can be used to differentiate the isobaric molecular ions of the compounds 5‐HTQ (M+) and 5‐MeODMT (MH+). The quantitative determination of certain indole alkaloids in the skin secretions of the Australian Golden Bell frog, Litoria aurea, by LC/ESI‐ion trap MS is also presented. The concentrations of 5‐HT, N′‐methyl 5‐HT and 5‐HTQ were found to be 2.68, 0.26 and 0.54 µg per mg of skin secretion, respectively. Copyright © 2002 John Wiley & Sons, Ltd.
Determination of naphthodianthrones and phloroglucinols from Hypericum perforatum extracts by liquid chromatography/tandem mass spectrometry
Authors: Tolonen Ari , Uusitalo Jouko , Hohtola Anja , Jalonen Jorma
Published: September 2002

Hypericum perforatum L. (St. John's Wort) has long been known as a medicinal plant, and has been used for the treatment of depression and neuralgic disorders. Its main active constituents are believed to be a naphthodianthrone, hypericin, and a phloroglucinol, hyperforin. A sensitive high performance liquid chromatography (HPLC)/electrospray tandem mass spectrometric method for fast simultaneous determination of six major naphthodianthrones and phloroglucinols of Hypericum perforatum extract has been developed. The method, based on multiple dissociation reaction monitoring (MRM), allows the analysis of hypericin, protohypericin, pseudohypericin, protopseudo‐hypericin, hyperforin and adhyperforin from the extract in less than 5 min. Good linearity over the range 0.1–1000 ng/mL for hyperforin and 2–500 ng/mL for hypericin was observed. Intra‐assay accuracy and precision varied from 2 to 19% within these ranges. Lower levels of quantitation for hyperforin were 0.5 ng/mL and 2 ng/mL for hypericin. Copyright © 2002 John Wiley & Sons, Ltd.
Fragmentation studies on monensin A and B by accurate‐mass electrospray tandem mass spectrometry
Authors: Lopes Norberto P. , Stark Christian B. W. , Hong Hui , Gates Paul J. , Staunton James
Published: September 2002

Monensin A and B were studied by electrospray ionisation tandem mass spectrometry (ESI‐MS/MS) and the fragment ions were confirmed by accurate‐mass measurements. Analyses were performed on both a quadrupole time‐of‐flight (QTOF) and a Fourier‐transform ion cyclotron resonance (FTICR) mass spectrometer. The analysis revealed that fragment ions were produced by Grob‐Wharton fragmentations and pericyclic rearrangements in addition to various simple neutral losses. A study of the protonated and sodiated sodium salt revealed different fragmentation pathways for these species, thus complementary structural information could be gained. A complete fragmentation pathway of monensin A and B protonated sodium salt [(M − H + Na) + H]+ and sodiated sodium salt [(M − H + Na) + Na]+ is proposed. MS3 analysis confirmed the separate fragmentation pathways. Copyright © 2002 John Wiley & Sons, Ltd.
Generic method for on‐line extraction of drug substances in the presence of biological matrices using turbulent flow chromatography
Authors: Herman J. L.
Published: September 2002

The use of liquid chromatography/mass spectrometry (LC/MS) to quantify drugs in biological matrices has been well established over the last decade. Extremely fast LC/MS methods are commonplace in the pharmaceutical industry for high‐throughput Absorption, Distribution, Metabolism and Excretion (ADME) screening. However, to truly take full advantage of high‐throughput ADME screening, a generic method is needed that eliminates the need to develop a new method for each new compound being screened. New developments in the stationary phase of turbulent flow columns has allowed us to develop an on‐line biological sample cleanup method that is suitable for over 99% of the compounds in the Cephalon database. Copyright © 2002 John Wiley & Sons, Ltd.