bluuebunny/crossref_metadata_2025_split huggingface dataset:
Molecular dynamics of HIV‐1 reverse transcriptase indicates increased flexibility upon DNA binding
Authors: Madrid Marcela , Lukin Jonathan A. , Madura Jeffry D. , Ding Jianping , Arnold Edward 
Published: August 2002

AbstractHIV‐1 reverse transcriptase (RT) is one of the main targets for drugs used in the treatment of AIDS, among them, the non‐nucleoside RT inhibitors (NNRTIs). The flexibility of RT unliganded and complexed to double‐stranded DNA (RT/dsDNA), in water, has been studied by means of molecular dynamics. The simulations show that RT flexibility depends on its ligation state. The RT/dsDNA trajectories show larger fluctuations in the atomic positions than uncomplexed RT, particularly at the tips of the p66 fingers and thumb subdomains. This increased flexibility is consistent with the ability of the p66 fingers of the RT/dsDNA complex to close down after the binding of a deoxynucleoside triphosphate (dNTP) molecule, as observed in the crystal structures of RT/dsDNA bound to dNTP. The two complexation states present different patterns of concerted motions, indicating that the bound dsDNA alters RT flexibility. The motions of amino acid residues that form the non‐nucleoside RT inhibitor binding pocket upon complexation with a NNRTI are anticorrelated with the p66 fingers (in RT/dsDNA) and correlated to the RNase H subdomain (unliganded RT). These concerted motions indicate that binding of a NNRTI could alter the flexibility of the subdomains whose motions are correlated to those of the binding pocket. Proteins 2001;45:176–182. © 2001 Wiley‐Liss, Inc.
Involvement of cytochrome P‐450 enzyme activity in the selectivity and safening action of pyrazosulfuron‐ethyl
Authors: Yun Min Soo , Shim Ie Sung , Usui Kenji 
Published: August 2002

AbstractTo investigate the selectivity and safening action of the sulfonylurea herbicide pyrazosulfuron‐ethyl (PSE), pyrazosulfuron‐ethyl O‐demethylase (PSEOD) activity involving oxidative metabolism by cytochrome P‐450 was studied in rice (Oryza sativa L cv Nipponbare) and Cyperus serotinus Rottb. Cytochrome P‐450‐dependent activity was demonstrated by the use of the inducers 1,8‐naphthalic anhydride and ethanol, the herbicides PSE, bensulfuron‐methyl, dimepiperate and dymron, or the inhibitor piperonyl butoxide (PBO). Growth inhibition in C serotinus seedlings was more severe than that in rice seedlings. O‐Dealkylation activities of PSE were induced differently in rice and in C serotinus, with distinctly higher activity in rice seedlings. The induced PSEOD activities were slightly inhibited by PBO in rice seedlings, whereas they were strongly inhibited in C serotinus seedlings. Dimepiperate and dymron were effective safeners of rice against PSE treatment. Treatments with herbicide alone resulted in less induction of PSEOD activity compared with combined treatments of the herbicide and safener. PSEOD activity in rice seedlings induced with herbicide alone was strongly inhibited by PBO, whereas it was weakly inhibited in rice seedlings induced with combinations of PSE and two safeners. These results suggest that O‐demethylation by cytochrome P‐450 enzymes may be involved in the metabolism of PSE and may contribute to its selectivity and safening action. Furthermore, these results suggest the existence of a multiple form of cytochrome P‐450 in plants.© 2001 Society of Chemical Industry
Photolysis of pesticides: influence of epicuticular waxes from Persica laevis DC on the photodegradation in the solid phase of aminocarb, methiocarb and fenthion
Authors: Pirisi Filippo M , Angioni Alberto , Cabizza Maddalena , Cabras Paolo , Cao Clara Falqui 
Published: August 2002

AbstractPesticides with N,N‐dimethyl and thiomethyl moieties (aminocarb, methiocarb and fenthion) were irradiated under artificial light (λ > 290 nm) in an amorphous wax phase from Persica laevis DC. The effect of the presence of the wax on the photolysis rate differed in the three pesticides, increasing it in aminocarb, having little effect in methiocarb and slowing it down in fenthion. The presence of the wax affected the qualitative photodegradation behaviour of all the pesticides. The data obtained were compared with those for pirimicarb, which had been studied earlier.© 2001 Society of Chemical Industry
Neonicotinoid insecticides alter diapause behavior and survival of overwintering white grubs (Coleoptera: Scarabaeidae)
Authors: Grewal Parwinder S , Power Kevin T , Shetlar David J 
Published: August 2002

AbstractThe chloronicotinyl, imidacloprid, and the thianicotinyl, thiamethoxam, are effective insecticides against white grubs when applied as preventative treatments during or immediately after egg laying. Their efficacy sharply declines when the grubs reach late‐instar stage. As both imidacloprid and thiamethoxam act on post‐synaptic nicotinic acetylcholine receptors and modify insect behavior, we hypothesized that the two compounds will interfere with overwintering behavior of scarabs, thus reducing their ecological fitness and exposing them to increased winter mortality. We tested this hypothesis by applying the two compounds curatively against late second‐instar and early third‐instar Popillia japonica and Cyclocephala borealis grubs in turfgrass. Imidacloprid provided control of P japonica equivalent to the most widely used curative organophosphate, trichlorfon, by 14 days after treatment, but thiamethoxam had no affect. In contrast, both imidacloprid and thiamethoxam caused significant reductions in C borealis populations. Both insecticides altered the overwintering behavior of P japonica by significantly reducing the normal downward movement of grubs in October. Halofenozide, an ecdysone agonist, also caused rapid mortality of the late second‐instar C borealis equivalent to trichlorfon, but had no affect on P japonica. In another experiment on a site naturally infested with entomopathogenic nematodes, the exclusive treatment of third‐instar P japonica with imidacloprid resulted in no significant mortality in the autumn (up to 15 days after treatment), but caused a significant reduction in the survival of overwintered grubs. There was an increase in the numbers of grubs infected with nematodes in the imidacloprid and trichlorfon treatments compared with control, but these differences were significant only for trichlorfon. These results indicate that imidacloprid can effectively control late second‐instars of both P japonca and C borealis and can significantly reduce survival of overwintered third‐instar P japonica by altering their normal overwintering behavior.© 2001 Society of Chemical Industry
An ecological risk assessment for spinosad use on cotton
Authors: Cleveland Cheryl B , Mayes Monte A , Cryer Steven A 
Published: August 2002

AbstractSpinosad is a reduced‐risk insecticide with a novel mode of action that provides an alternative to older classes of insecticides such as organophosphates, carbamates and pyrethroids. A comprehensive ecological risk assessment for spinosad use in US cotton crops is presented within a framework of tiered levels of refinement following the guidelines of the US EPA for ecological risk assessments. Toxicity information for a variety of species is documented and utilized, environmental concentrations estimated, and risk characterizations in the form of risk quotients are quantified. Results indicate that spinosad use in cotton does not exceed the most conservative Tier I levels of concern (LOC) values for groundwater, mammals and birds or acute risk to aquatic organisms. Use of very conservative Tier I screening methods resulted in exceeding LOC values for chronic exposure for some aquatic organisms, thus prompting further refinement. When the exposure prediction was refined using less conservative, Tier II mechanistic environmental fate transport models to predict off‐site transport and environmental concentrations, chronic risk was not predicted for these species. Spinosad is acutely toxic to bees under laboratory conditions, but toxicity of residue studies and field studies indicate that under actual use conditions the impact on bees is minimal.© 2001 Society of Chemical Industry
Fumigant activity of (E)‐anethole identified in Illicium verum fruit against Blattella germanica
Authors: Chang Kyu‐Sik , Ahn Young‐Joon 
Published: August 2002

AbstractThe insecticidal activities of materials derived from the fruit of star anise, Illicium verum, against adults of Blattella germanica were examined by direct contact application and fumigation methods, and compared with those of DDVP, deltamethrin and hydramethylnon. The biologically active constituent of the Illicium fruit was characterized as the phenylpropene, (E)‐anethole, by spectroscopic analysis. In a filter paper diffusion test with females, (E)‐anethole caused 80.3% mortality at 0.159 mg cm−2 at 1 and 3 days after treatment (DAT), whereas 16.7% mortality at 3 DAT was achieved at 0.079 mg cm−2. DDVP and deltamethrin gave >90% mortality at 0.019 mg cm−2 at 1 DAT. At 0.009 mg cm−2, DDVP and deltamethrin showed 73.3 and 60% mortality at 1 DAT, respectively, but 93.3 and 76.7% mortality at 3 DAT. Hydramethylnon exhibited 0 and 93.3% mortality at 0.159 mg cm−2 at 1 and 3 DAT, respectively, whereas 6.7% mortality at 3 DAT was observed at 0.079 mg cm−2. In a fumigation test with females, (E)‐anethole was much more effective in closed cups than in open ones, indicating that the insecticidal activity of the compound was largely attributable to fumigant action. (E)‐Anethole and DDVP caused 100% mortality at 0.398 and 0.051 mg cm−2 4 and 1 h after treatment, respectively. (E)‐Anethole showed 46.7% mortality at 0.199 mg cm−2 at 3 DAT, whereas deltamethrin and hydramethylnon at 0.796 mg cm−2 was ineffective for 3‐day period. As naturally occurring insect‐control agents, the I verum fruit‐derived materials described could be useful for managing populations of B germanica.© 2001 Society of Chemical Industry
Discharge consents in Scotland
Authors: Rosie Andrew J , Singleton Peter T R 
Published: August 2002

AbstractThe Scottish Environment Protection Agency (SEPA) is charged with the protection of the Scottish environment, and this is achieved through the regulation of polluting discharges and through consulting, influencing and educating others who interact with it. This paper describes aspects of the agency's regulatory work as it applies to the Scottish fish‐farming industry. By far the largest sector of the industry in Scotland involves the rearing of fin‐fish in cages, presently still dominated by Atlantic salmon, and the paper is based on experiences gained within this sector. The present circumstances affecting its development are described with reference to the environmental impacts associated with cage‐rearing techniques used for production in marine waters. This paper briefly reviews the statutory background behind Scotland's system of discharge consents, including relevant aspects of European legislation. Methods developed to control the environmental risks posed by sea louse treatment chemicals are described. The concept of farming the sea is explored in relation to SEPA's ‘allowable zone of effects’ approach and the growing public concern about perceived environmental damage. Finally, the future prospects for the industry in Scotland are reviewed in relation to sea louse control.© 2002 Society of Chemical Industry
Solid‐phase synthesis of a dendritic peptide related to a retinoblastoma protein fragment utilizing a combined boc‐ and fmoc‐chemistry approach
Authors: Cavallaro Vittoria , Thompson Philip , Hearn Milton 
Published: August 2002

AbstractDendritic peptides, often presented as multiple antigen peptides (MAPs), are widely used in immunological‐based fields of research, although their synthesis can be extremely challenging. In this paper, a tetrameric dendritic MAP‐like presentation of the retinoblastoma protein [649‐654] sequence (4RB649‐654) has been prepared using solid‐phase peptide synthesis (SPPS) methods. During the synthesis of this dendritic molecule, numerous modifications to the synthetic protocols were examined. These modifications included the introduction of a combination Boc‐ and Fmoc‐chemistry approach and also the use of 1,8‐diazabicyclo[5.4.0]‐undec‐7‐ene as a Fmoc‐deprotection agent. The use in combination of Boc‐ and Fmoc‐based synthetic strategies resulted in the production of the desired peptide molecule, 4RB649‐654, in high purity and acceptable yields following purification by reversed phase HPLC. Copyright © 2001 European Peptide Society and John Wiley & Sons, Ltd.
Synthesis of oligopeptides with the sequence SXWS and their chemotactic effects on a ciliated protozoan Tetrahymena pyriformis
Authors: Illyés Eszter , Hudecz Ferenc , Köhidai László , Láng Orsolya , Szabó Pál , Sebestyén Ferenc 
Published: August 2002

AbstractIn this paper, the solid phase synthesis and chemical characterization of members of an SXWS sub‐library (SAWS, SDWS and SKWS) as well as the comparison of their chemotactic properties with those of SEWS, which exhibits a prominent effect at 10−12 M on a ciliated protozoan, Tetrahymena pyriformis, are described. We found that the chemotaxis of cells induced with the SXWS peptides varied according to the nature of the amino acid residue (Ala, Asp, Lys) in position X. The chemotactic activity of SEWS was not surpassed by any of three new tetrapeptides, although SAWS was also chemoattractant. Interestingly, SDWS, with an acidic side chain at position X, could not elicit any chemotactic response. SKWS, however, showed mild but significant chemorepellent activity over a wide concentration range. Chemotactic selection studies showed that the two chemoattractant peptides (SAWS and SEWS) had an expressed ability to select high‐responder offspring cell populations. Peptides with neutral (SDWS) or chemorepellent (SKWS) properties were not able to select such subpopulations from the mixed cultures of Tetrahymena, indicating that the chemotactic response elicited by SXWS peptides is ligand‐specific. For ligand‐binding experiments N‐terminally labelled fluorescent derivatives of SXWS peptides were prepared, applying [4‐[7‐hydroxycoumaryl]]acetic acid (Hca‐OH) or 4‐ethoxymethylene‐2‐[1]‐naphthyl‐5(4H)‐oxazolone (naOx‐OEt) as markers. Hca‐OH was introduced using an active ester technique as the last step of SPPS, or after cleavage in solution. The oxazolone naOx‐OEt reacted with the amino group of the peptide by liberation of EtOH. The binding characteristics of fixed Tetrahymena cells with the naOx‐labelled peptides showed good correlation between binding profiles and chemotactic responsiveness (SEWS > SAWS > SDWS ∼ SKWS). A similar binding pattern was observed in the case of Hca‐peptides (SEWS > SAWS > SDWS). Hca‐SKWS, however, bound remarkably to the cell surface. The binding activity of the Hca‐peptides was less pronounced than that of the naOx‐peptides, indicating the importance of the fluorophores applied. Copyright © 2002 European Peptide Society and John Wiley & Sons, Ltd.
Passive control technologies for seismic‐resistant buildings in Europe
Authors: Mazzolani Federico M 
Published: August 2002

AbstractA bird's‐eye view of the main passive control technologies used in European earthquake‐prone countries for seismic protection of civil buildings is presented. After some remarks on the general situation in Europe, which identify Italy as a leading country in this field, the special types of devices used in passive control technologies are analysed. Some relevant examples of applications are illustrated, both for seismic protection of new buildings and for rehabilitation of existing buildings. Current developments in codification (design codes and guidelines) are also examined. Finally, an overview of recent European research projects recognise some interesting issues, which promise future improvements in passive control technology.
Effect of the traditional medicinal plants Rhazya stricta, Balanitis aegyptiaca and Haplophylum tuberculatum on paracetamol‐induced hepatotoxicity in mice
Authors: Ali B. H. , Bashir A. K. , Rasheed R. A. 
Published: August 2002

AbstractThis work examines the effects of lyophilized extracts of the medicinal plants Rhazya stricta, Balanites aegyptiaca and Haplophylum tuberculatum on liver damage induced by paracetamol in mice. Rapid HPLC finger prints for some of these extracts were made. The hepatoprotective effects of the plant extracts were compared with that of the standard hepatoprotective agent silymarin. The extracts (1 g/kg) and silymarin (0.1 g/kg) were given orally for 5 consecutive days .On the last day of treatment a hepatotoxic oral dose of paracetamol (0.6 g/kg) was given, and 3 h later, the hepatic function of mice was evaluated using pentobarbitone ‐induced sleeping time, the concentration of reduced glutathione (GSH) in liver, and the activities of aspartate aminotransferase (AST), alanine aminotransferase (ALT), γ‐glutamyl transferase (GGT) and cholesterol concentration in plasma. The livers were weighed and examined for macro‐ and microscopic changes. Pretreatment with R. stricta or with silymarin protected the livers of treated mice against paracetamol hepatotoxicity as evidenced by a significant improvement of the above liver function tests. B. Aegyptiaca had a relatively modest hepatoprotective activity, while H. tuberculatum was almost ineffective.Oral pretreatment of mice for 5 consecutive days with an extract of R. stricta or silymarin protected about 57% and 92% of the treated mice, respectively, against the lethal effect of paracetamol (1 g/kg). B. aegyptiaca and H. tuberculatum protected only 27% and 16% of the animals, respectively. Copyright © 2001 John Wiley and Sons, Ltd.
The effect of Polbax extract on lipofuscin accumulation in cultured neonatal rat cardiac myocytes
Authors: Terman Alexei , Brunk Ulf T. 
Published: August 2002

AbstractPolbax®, a water‐soluble extract of fresh pollen grains and pistils, was tested for its ability to influence the accumulation of lipofuscin (age pigment) in cultured neonatal rat cardiac myocytes. Exposure for 3 weeks to Polbax at concentrations of 0.1, 1.0 or 10 mg/L decreased lipofuscin accumulation morphometrically assayed using laser scanning microscopy images (green excitation light) of formaldehyde‐fixed cells, by 24%, 41% or 43%, respectively. Based on the knowledge that oxidative stress and iron‐catalysed peroxidation play an important role in lipofuscinogenesis, we suggest that Polbax may slow lipofuscin formation due to antioxidant activities, perhaps involving intralysosomal dismutation of superoxide produced by autophagocytosed mitochondria and/or iron‐chelation. Copyright © 2002 John Wiley & Sons, Ltd.
Antimicrobial properties of the essential oil of Artemisia asiatica Nakai
Authors: Kalemba D. , Kusewicz D. , Świa̧der K. 
Published: August 2002

AbstractThe antibacterial and antifungal activity of the essential oil of Artemisia asiatica Nakai, its main constituents: 1,8‐cineole and selin‐11‐en‐4α‐ol and monoterpene alcohols fraction were determined against Bacillus subtilis, Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, Candida albicans, Rhodotorula rubra and Aspergillus fumigatus. The oil exhibited a good inhibitory activity against bacteria and fungi. The monoterpene alcohols fraction showed the highest antibacterial activity. Copyright © 2002 John Wiley & Sons. Ltd.
Synthesis of plumbagin derivatives and their inhibitory activities against Ehrlich ascites carcinoma in vivo and Leishmania donovani Promastigotes in vitro
Authors: Hazra Banasri , Sarkar Rajes , Bhattacharyya Saswati , Ghosh Prabir K. , Chel Gautam , Dinda Biswanath 
Published: August 2002

AbstractPlumbagin, a plant‐derived bioactive naphthoquinonoid compound, was converted to a hydroquinonoid derivative, which was studied for its tumour‐inhibitory and antileishmanial activities for the first time. A similar chemical transformation was undertaken on an analogous dimeric compound, diospyrin, and its bioassay results were compared with those of the plumbagin derivative. Synthesis of the derivative of plumbagin did not result in a marked enhancement of the tumour‐inhibitory activity, whereas the improvement was obvious in the case of diospyrin vis à vis its hydroquinonoid analogue. The conversion of diospyrin to the hydroquinonoid compound also led to a substantial increase in the antileishmanial activity, while a similar conversion of plumbagin failed to do so. Copyright © 2002 John Wiley & Sons, Ltd.
Antiulcerogenic and analgesic effects of the Austroplenckia populnea extracts in mice
Authors: Seito L. N. , Mazaro R. , Di Stasi L. C. 
Published: August 2002

AbstractAustroplenckia populnea (Reiss.) Lund. is a Brazilian Cerrado plant belonging to the Celastraceae family. Hexane and methanol extracts of leaves were investigated for their antiulcerogenic (ethanol and indomethacin/bethanecol induced gastric damage) and analgesic (writhing and tail‐flick tests) activities in mice. Acute toxic effects also were evaluated. Oral administration of both extracts at a dose of 1000 mg/kg significantly reduced the total area of the lesion, the relative area of lesion and the ulcerative index in ethanol‐induced gastric damage, but both extracts were inactive in the indomethacin/bethanecol‐induced gastric damage test. A dose dependent effect was determined with the hexane extract in the ethanol‐induced lesions test. The hexane and methanol extracts reduced the number of contortions in the writhing test, but both extracts were inactive in the tail‐flick immersion test. Copyright © 2002 John Wiley & Sons, Ltd.
A new method for the determination of cushion curves
Authors: Sek Michael A. , Minett Merv , Rouillard Vincent , Bruscella Ben 
Published: August 2002

AbstractA new method for the measurement of shock‐absorbing characteristics of cushioning materials and determination of ‘cushion curves’ is discussed in this paper. The method not only significantly reduces testing time but also improves the accuracy of the estimate of a cushion curve. Cushion curves are determined from the material's static compression characteristics and the impact data (static load/peak acceleration) obtained from a small number of impacts on a cushion tester. However, the method is capable of producing a cushion curve from the measurement of just a single impact. The process involves an iterative least mean squares (ILMS) minimisation of the discrepancy between peak acceleration values predicted from a theoretical model and measured in the impact tests. The algorithm of the ILMS method, examples demonstrating its application and the dynamic effect in impacts of various materials such as the EPU, the EPS and corrugated fibreboard are presented. Copyright © 2000 John Wiley & Sons, Ltd.
Determination of ϵ‐caprolactam migration from polyamide plastics: a new approach
Authors: Pogorzelska Z. , Mielniczuk Z. 
Published: August 2002

AbstractA new gas chromatography method for determination of ϵ‐caprolactam (CPR) migration from packaging materials such as: polyamide (PA) films, PA granulates, PA/PE (polyethylene) laminates, PA casings, etc., to food simulants has been developed. Water, 3% w/v acetic acid, 15% and 95% v/v ethanol and olive oil have been used as a food simulants. Using the 1,4‐butanediol (BUG) as an internal standard (instead of aza‐2‐cyclononanone), calibration curves were constructed. Very good separation of CPR from BUG was achieved by using a Nukol fused silica capillary column (Supelco), 25 m × 0.32 mm. The time of analysis is shorter than 12 min: 7.69 min for BUG and 11.60 min for CPR. The regression line equation for CPR migration to water is: y = 0.080x + 0.14; to olive oil: y = 0.010x. The sensitivity of the developed method is appropriate for the quantitative determination of CPR in an analyte concentration of approximately 0.2 mg/kg, when the specific migration limit (SML) for this compound, according to Directive 90/128/EEC, is 15 mg/kg food simulant. Copyright © 2001 John Wiley & Sons, Ltd.