bluuebunny/crossref_metadata_2025_split huggingface dataset:
Structural investigation of water‐induced phase transitions of poly(ethylene imine). III. The thermal behavior of hydrates and the construction of a phase diagram
Authors: Hashida Tomoko , Tashiro Kohji , Inaki Yoshiaki 
Published: October 2003

AbstractThe thermal behavior of poly(ethylene imine) (PEI) hydrates in a water vapor atmosphere was investigated through temperature‐dependent measurements of infrared spectra and X‐ray diffraction. Almost perfectly dried anhydrate melted at about 60 °C during the heating process. Anhydrate containing a small amount of water showed a phase transition to a mixture of hemihydrate and sesquihydrate around 40 °C, at which point the ethylene imine (EI)/water ratio was 1/0.5 in the hemihydrate and 1/1.5 in the sesquihydrate. The hemihydrate transferred to the sesquihydrate around 60 °C, and the latter melted above 80 °C. When the starting PEI sample contained a greater amount of water and consisted of hemihydrate and sesquihydrate, the hemihydrate transferred to the sesquihydrate via heating, and the latter melted around 75 °C. For a sample of dihydrate (EI/water ratio = 1/2) containing an appreciably large amount of water, it transferred to the sesquihydrate around 65 °C, and the latter melted above 90 °C. A sample of dihydrate with a much higher water content existed up to 110 °C and then melted; during this period, no transition to the sesquihydrate was observed. In this way, the starting crystalline phases were found to change for anhydrate and various types of hydrates. Their transition behaviors varied according to the water content. From these data, a phase diagram was successfully derived as a function of the temperature and water content. This phase diagram allowed us to predict the transition behavior during the hydration process at various constant temperatures. For example, at 60 °C, a molten sample should crystallize into a mixture of hemihydrate and sesquihydrate at first, and the hemihydrate should transfer to the sesquihydrate with increasing water content. The latter should change to the dihydrate in the final stage. This prediction was checked with time‐resolved measurements of X‐ray diffraction and infrared spectra during the hydration process at the corresponding temperature; this led to the establishment of the phase diagram. © 2003 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 41: 2937–2948, 2003
Crystallization behavior and thermal stability of poly(trimethylene terephthalate)/clay nanocomposites
Authors: Ou Cheng‐Fang 
Published: October 2003

AbstractPoly(trimethylene terephthalate) (PTT)/montmorillonite (MMT) nanocomposites were prepared by the solution intercalation method. Two different kinds of clay were organomodified with an intercalation agent of cetyltrimetylammonium chloride (CMC). X‐ray diffraction (XRD) indicated that the layers of MMT were intercalated by CMC, and interlayer spacing was a function of the cationic exchange capacity of clay. The XRD studies demonstrated that the interlayer spacing of organoclay in the nanocomposites depends on the amount of organoclay. From the results of differential scanning calorimetric analysis, it was found that clay behaves as a nucleating agent and enhances the crystallization rate of PTT. The maximum enhancement of the crystallization rate for the nanocomposites was observed in nanocomposites containing about 1 wt % organoclay with a range of 1–15 wt %. From thermogravimetric analysis, we found that the thermal stability of the nanocomposites was enhanced by the addition of 1–10 wt % organoclay. According to transmission electron microscopy, the organoclay particle was highly dispersed in the PTT matrix without a large agglomeration of particles for a low organoclay content (5 wt %). However, an agglomerated structure did form in the PTT matrix at a 15 wt % organoclay content. © 2003 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 41: 2902–2910, 2003
Characterization of heavy ion tracks in polymers by transmission electron microscopy
Authors: Adla A. , Fuess H. , Trautmann C. 
Published: October 2003

AbstractUltrathin sections of two polymers—poly(ethylene terephthalate) and polyimide—were irradiated with heavy ions of 11.1 MeV per nucleon. The size and morphology of the latent tracks were examined with transmission electron microscopy. Polymers readily decomposed under the imaging electron beam. Samples were therefore stained with either osmium tetroxide or ruthenium tetroxide before and/or after ion irradiation. This treatment significantly reduced the radiolytic sensitivity. In addition, however, with dynamic video electron imaging, quasi‐instantaneous damage processes were observed within seconds of observation, modifying in particular both tracks in the bulk and to a lesser extent those on the two confining surfaces. The staining agent was embedded into amorphous regions of the matrix as metallic nanoparticles. Prestained tracks appeared as bright cylindrical regions with diameters of ∼6–10 nm. In ultrathin samples, the central track region showed a significant loss of material and even an open hole. Following poststaining, tracks exhibited a dark contrast because of preferential diffusion of the staining agent into the tracks. Poststained tracks were larger than prestained tracks. © 2003 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 41: 2892–2901, 2003
Solubility of N2 in poly(α‐n‐hexyl‐β,L‐aspartate): Temperature and force‐field dependence
Authors: Zazueta D. Alfonso , Curcó David , Alemán Carlos , Muñoz‐Guerra Sebastián 
Published: October 2003

AbstractThe solubility of N2 in poly(α‐n‐hexyl‐β,L‐aspartate), a stereoregular poly(β‐peptide), was investigated with atomistic Monte Carlo simulations. The structure of this material is intermediate between that of polymers able to form a three‐dimensional crystal lattice and that of liquid‐crystalline polymers with a biphasic distribution. The dependence of the calculated solubility coefficients on both the parameters of the force field and the temperature was examined. The results are compared with recently reported experimental data. Furthermore, the motion of the penetrant molecules within the polymer matrix was analyzed. © 2003 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 41: 2928–2936, 2003
Time‐resolved Fourier transform infrared/attenuated total reflection spectroscopy for the measurement of molecular diffusion in polymers
Authors: Elabd Yossef A. , Baschetti Marco Giacinti , Barbari Timothy A. 
Published: October 2003

AbstractOver the past 2 decades, the use of time‐resolved Fourier transform infrared/attenuated total reflection (ATR) spectroscopy for the measurement of diffusion in polymers has grown. ATR is a powerful technique for the measurement of diffusion in polymers because it is an in situ technique that is relatively inexpensive, provides reliable short‐time data, and provides a wealth of information at the molecular level. This article highlights the technique and its application to numerous studies, ranging from the diffusion of drugs in human skin to chemical warfare agents in barrier materials. In addition to these topics, recent studies with ATR to quantify and model molecular interactions during the diffusion process are reviewed. In the future, the ATR technique may have an impact on a variety of emerging fields in which diffusion in polymers plays an important role, such as fuel cells, membrane separation, sensors, and drug delivery. © 2003 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 41: 2794–2807, 2003
Macromolecules at surfaces: Research challenges and opportunities from tribology to biology
Authors: Granick Steve , Kumar Sanat K. , Amis Eric J. , Antonietti Markus , Balazs Anna C. , Chakraborty Arup K. , Grest Gary S. , Hawker Craig , Janmey Paul , Kramer Edward J. , Nuzzo Ralph , Russell Thomas P. , Safinya Cyrus R. 
Published: October 2003

AbstractA comprehensive review of ongoing and recommended research directions concerning the structure, dynamics, and interfacial activity of synthetic and naturally occurring macromolecules at the solid–liquid interface is presented. Many new developments stem from the ability to target new size regimes of 1–100 nm. These rapid developments are reviewed critically with respect to chemical synthesis, processing, structural characterization, dynamic processes, and theoretical and computational analysis. The common problems shared by flat and particulate surfaces are emphasized. A broad spectrum of material properties are discussed, from the control of interfacial friction between surfaces in moving contact, to the mechanical strength and durability of the interfaces in hybrid materials, to optical and electronic properties. Future research opportunities are identified that involve (1) the emergence of nanoscale material properties, (2) polymer‐assisted nanostructures, and (3) the crossroads between interfacial science and biological and bioinspired applications. © 2003 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 41: 2755–2793, 2003
Acaricidal effects of cardiac glycosides, azadirachtin and neem oil against the camel tick, Hyalomma dromedarii (Acari: Ixodidae)
Authors: Al‐Rajhy DiefAlla H , Alahmed Azzam M , Hussein Hamdy I , Kheir Salah M 
Published: October 2003

AbstractThe cardiac glycoside, digitoxin, from Digitalis purpurea L (Scrophulariaceae), a cardiac glycosidal (cardenolide) extract from Calotropis procera (Ait) R Br (Asclepiadaceae), azadirachtin and neem oil from Azadirachta indica A Juss (Meliaceae) were tested for their effects against larvae and adult stages of the camel tick, Hyalomma dromedarii Koch (Acari: Ixodidae). The contact LC50 values of the first three materials against adults were 4.08, 9.63 and >40.7 µg cm−2, respectively, whereas the dipping LC50 values of the four materials were 409.9, 1096, >5000 and >5000 mg litre−1, respectively. Contact and dipping LC50 values of the extract and azadirachtin against larvae were 6.16, >20.3 µg cm−2 and 587.7 and >2500 mg litre−1, respectively. Azadirachtin had no effects on egg production or feeding of adults up to 5000 mg litre−1; however at 2500 mg litre−1, it caused significant reduction in feeding activity of larve, prolonged the period for moulting to nymphal stage, and caused 60% reduction in moultability. Results of the two cardiac glycoside materials are comparable with those of several commercial acaricides. The risks and benefits associated with the use of cardiac glycosides are considered. Copyright © 2003 Society of Chemical Industry
Association of MACE‐based insecticide resistance in Myzus persicae with reproductive rate, response to alarm pheromone and vulnerability to attack by Aphidius colemani
Authors: Foster Stephen P , Kift Neil B , Baverstock Jason , Sime Sue , Reynolds Kelly , Jones Julie E , Thompson Robin , Tatchell G Mark 
Published: October 2003

AbstractReproductive success and response to alarm pheromone, both potentially important components of fitness, were assessed using clones of Myzus persicae (Sulzer) to establish associations with insecticide resistance conferred by insensitive modified acetylcholinesterase (MACE). Both traits showed significant trends that were apparently related to this mechanism. MACE forms appeared to reproduce at slower rates than non‐MACE forms expressing moderate (R1) levels of another resistance mechanism based on elevated carboxylesterase. However, MACE forms were more responsive to alarm pheromone than their non‐MACE counterparts. The potential implications for parasitoid performance were tested using two clones showing clear differences in alarm response. The level of parasitism of M persicae by the parasitoid Aphidius colemani (Viereck) was significantly lower in MACE forms on pepper crops compared to non‐MACE forms. In addition, the distribution of MACE and non‐MACE forms differed on the pepper plants, with more MACE forms being found on the growing points. The presence of the parasitoid A colemani did not alter this change in distribution. Copyright © 2003 Society of Chemical Industry
Chlorpyrifos residue levels in avian food items following applications of a commercial EC formulation to alfalfa and citrus
Authors: Brewer Larry W , McQuillen Harry L , Mayes Monte A , Stafford Jennifer M , Tank Susan L 
Published: October 2003

AbstractTwo 10‐day field residue studies were conducted to measure the amount of chlorpyrifos residue found in typical avian food following applications of a commercial 480 g liter−1 EC (Lorsban® 4E) at 1.1 kg AI ha−1 (1 lb AI acre−1) to alfalfa and at 2.3 kg AI ha−1 (2.0 lb AI acre−1) to citrus. Avian food items used in these studies included: crickets (Acheta domestica (L)), earthworms (Lumbricus terrestris L), darkling ground beetle larvae (Tenebrio molitor L), seed heads (Triticum sp), and naturally occurring flying and ground‐dwelling insects. The studies incorporated a design involving three main study plots placed within larger treated areas of an alfalfa crop and a mature orange grove. The three main study plots represented three replications and each contained four sub‐plots. One sub‐plot, on each study plot, was sampled on day 0 (2‐h post‐application), day 1, day 5 and day 10 post‐application. Chlorpyrifos residues were present in all avian food sampled following the application; however, residue levels were lower than estimated residue values typically used by the US EPA to establish expected environmental concentration (EEC) used in screening assessments of risk to terrestrial wildlife. Copyright © 2003 Society of Chemical Industry
Inheritance of resistance to Bt canola in a field‐derived population of Plutella xylostella
Authors: Sayyed Ali H , Schuler Tanja H , Wright Denis J 
Published: October 2003

AbstractCrops expressing Bacillus thuringiensis (Bt) insecticidal Cry proteins are grown on millions of hectares. Recommendations to delay resistance are based on a high expression/refugia strategy that aims to kill resistant heterozygotes and enable some susceptible insects to survive. Leaf‐dip bioassays on F1 crosses of Malaysian populations of diamondback moth (Plutella xylostella (L)) showed that Cry1Ac resistance was not fully recessive. The survival of ca 50% of heterozygotes on Bt canola (Brassica napus L) leaves expressing low concentrations of Cry1Ac agreed with a non‐fully‐recessive model for resistance. Extrapolations based on log dose‐logit mortality regressions for heterozygotes using leaf‐dip bioassays showed that a relatively high level of expression, of ca 2000 ng Cry1Ac mg−1 total leaf protein, would be required to give 90% mortality to heterozygotes. If high enough levels of expression of Bt toxin to kill heterozygotes cannot be achieved and maintained under field conditions, the effectiveness of the high‐dose/refugia strategy would be reduced. Copyright © 2003 Society of Chemical Industry
The effects of repeated applications of the molluscicide metaldehyde and the biocontrol nematodePhasmarhabditis hermaphroditaon molluscs, earthworms, nematodes, acarids and collembolans: a two‐year study in north‐west Spain
Authors: Iglesias Javier , Castillejo José , Castro Ramón 
Published: October 2003

AbstractOver two years, six consecutive field experiments were done in which the chemical molluscicide metaldehyde and the nematode biocontrol agentPhasmarhabditis hermaphrodita(Schneider) were applied at the standard field rates to replicated mini‐plots successively planted with lettuce, Brussels sprouts, leaf beet and cabbage, to compare the effectiveness of different treatments in reducing slug damage to the crops. Soil samples from each plot were taken prior to the start of the experiments, and then monthly, to assess the populations of slugs, snails, earthworms, nematodes, acarids and collembolans. The experiments were done on the same site and each plot received the same treatment in the six experiments. The six treatments were: (1) untreated controls, (2) metaldehyde pellets, (3 and 4) nematodes applied to the planted area 3 days prior to planting without or with previous application of cow manure slurry, (5) nematodes applied to the area surrounding the planted area 3 days prior to planting, and (6) nematodes applied to the planted area once (only in the first of the six consecutive experiments). Only the metaldehyde treatment and the nematodes applied to the planted area at the beginning of each experiment without previous application of manure significantly reduced slug damage to the plants, and only metaldehyde reduced the number of slugs contaminating the harvested plants. The numbers of slugs, snails and earthworms in soil samples were compared among the six treatments tested: with respect to the untreated controls, the numbers ofDeroceras reticulatum(Müller) were significantly affected only in the metaldehyde plots, and the numbers ofArion aterL only in the plots treated with nematodes applied to the planted area 3 days prior to planting without previous application of manure; numbers of snails (Ponentina ponentina(Morelet) andOxychilus helveticus(Blum)) were not affected by the treatment. The total numbers of all earthworm species and ofLumbricusspp were unaffected by the treatment, butDendrobaenaspp increased significantly in the plots treated with manure. The numbers of nematodes, acarids and collembolans in soil samples were compared between the untreated controls and the treatments with nematodes applied 3 days prior to planting to the planted area or to the surrounding area, without previous application of manure: the treatment had a significant effect on the number of nematodes in soil samples, but acarids and collembolans were unaffected. Copyright © 2003 Society of Chemical Industry
Genetic basis of resistance and studies on cross‐resistance in a population of diamondback moth, Plutella xylostella (Lepidoptera: Plutellidae)
Authors: Liang Pei , Gao Xi‐Wu , Zheng Bing‐Zong 
Published: October 2003

AbstractThe genetic basis of abamectin resistance was studied in a strain of the diamondback moth, Plutella xylostella (L), following laboratory selection of a field population collected at Xuanhua, Hebei Province, China. Data from the testing of F1 progeny from reciprocal crosses between abamectin‐resistant and abamectin‐susceptible strains indicated that resistance might be autosomal and incompletely recessive with a degree of dominance of −0.13. Chi‐squared analyses from the response of a backcross of crossed F1 progeny and the resistant strain and F2 progeny were highly significant, suggesting that the resistance was probably controlled by more than one gene. The results of cross‐resistance studies showed that there was little cross‐resistance between abamectin and four pyrethroid insecticides (deltamethrin, beta‐cypermethrin, fenvalerate and bifenthrin) and no cross‐resistance between abamectin and the acylureas chlorfluazuron or flufenoxuron. Copyright © 2003 Society of Chemical Industry
Antitumor activity of total alkaloid fraction of solanum pseudocapsicum leaves
Authors: Badami Shrishailappa , Manohara Reddy S. A. , Kumar E. P. , Vijayan P. , Suresh B. 
Published: October 2003

AbstractThe total alkaloid fraction of the methanolic extract of Solanum pseudocapsicum leaves was tested for its in‐vivo antitumor activity against Dalton's Lymphoma Ascites model in mice. The total alkaloid fraction at 2.5 and 5.0 mg/kg body weight doses exhibited antitumor activity as revealed by the signiﬁcant increase in the mean survival time and the percentage increase in life span of tumor bearing mice. The antitumor activity observed may be due to its cytotoxic properties. However the treatment caused a signiﬁcant decrease in the body weight below the normal indicating the toxicity of the treatment. Copyright © 2003 John Wiley & Sons, Ltd.
Antiﬁlarial potential of the fruits and leaves extracts of Pongamia pinnata on cattle filarial parasite Setaria cervi
Authors: Uddin Qamar , Parveen Nazneen , Khan Nizam U. , Singhal K. C. 
Published: October 2003

AbstractThe effect of aqueous and alcohol extracts of the fruits and leaves of Pongamia pinnata (Linn.) Merr. (Syn. Pongamia glabra Vent, leguminosae) on the spontaneous movements of both the whole worm and the nerve–muscle preparation of Setaria cervi and on the survival of microﬁlariae in vitro was studied. The aqueous and alcohol extracts of fruits and the alcohol extract of leaves caused an inhibition of spontaneous movements of the whole worm and the nerve–muscle preparation of S. cervi. The initial stimulatory effect was not observed with the aqueous extract of fruits on the nerve–muscle preparation. The concentration required to inhibit the movements of the whole worm preparation was 250 µg/mL for aqueous, 120 µg/mL for alcohol extract of fruits and 270 µg/mL for alcohol extracts of the leaves. The concentrations of P. pinnata extracts required to produce an equivalent effect on the nerve–muscle preparation were 25 µg/mL, 5 µg/mL and 20 µg/mL, respectively, suggesting a cuticular permeability barrier. Copyright © 2003 John Wiley & Sons, Ltd.
Antimicrobial activity of essential oil and methanol extracts of Achillea sintenisii Hub. Mor. (Asteraceae)
Authors: Sökmen Atalay , Vardar‐Ünlü Gülhan , Polissiou Moschos , Daferera Dimitra , Sökmen Münevver , Dönmez Erol 
Published: October 2003

AbstractThe essential oil, obtained by Clevenger distillation, and water‐soluble and water‐insoluble parts of the methanol extracts of Achillea sintenisii Hub. Mor. were individually assayed for their antimicrobial activities against 12 bacteria and two yeasts, Candida albicans and C. krusei. No activity was exhibited by the water‐soluble subfraction, whereas both the water‐insoluble subfraction of the methanol extracts and the essential oil were found to be active against some test microorganisms studied. Since the essential oil possessed stronger activity than the other extracts tested, it was further fractionated and the fractions were evaluated for their antimicrobial activity, followed by GC‐MS analysis, resulting in the identiﬁcation of 32 compounds which constituted 90.2% of the total oil. The GC‐MS analysis of the oil and its fractions revealed that the main components of the oil, e.g. camphor and eucalyptol, possessed appreciable activity against C. albicans and Clostridium perfringens. The ﬁndings presented here also suggest that the other constituents of the oil, e.g. borneol and piperitone can also be taken into account for the activity observed. Copyright © 2003 John Wiley & Sons, Ltd.
Effect of 14‐deoxyandrographolide on calcium‐mediated rat uterine smooth muscle contractility
Authors: Burgos Rafael A. , Loyola Mario , Hidalgo María A. , Labranche Timothy P. , Hancke Juan L. 
Published: October 2003

AbstractIn this study, the effect of 14‐deoxyandrographolide (14‐DAP) on calcium channel‐dependent rat uterine smooth muscle contraction was evaluated. Using a tissue bath preparation, 14‐DAP was able to reduce the contractile response to 0.3 and 3.0 mm of CaCl2, with an IC50 of 1.24 ± 0.23 × 10−5 m and 5.94 ± 0.29 × 10−5 m, respectively. 14‐DAP shifted the CaCl2 cumulative dose response curve to the right, increasing the EC50 from 2.08 ± 0.20 × 10−4 m to 4.22 ± 0.22 × 10−4 m (5 µm 14‐DAP) and 2.5 ± 1.0 × 10−3 m (50 µm 14‐DAP). In order to determine if 14‐DAP had any effect on intracellular calcium, the relaxant response to 14‐DAP following contraction by oxytocin, PGF2α and vanadate in Ca+2‐free solution was compared with that of isoproterenol and phenylbutazone. While isoproterenol and phenylbutazone relaxed the smooth muscle in a dose‐dependent manner, 14‐DAP did not have any effect on either the oxytocin, PGF2α or vanadate‐induced smooth muscle contraction. Based on these data, it appears that 14‐DAP is an uterine smooth muscle relaxant which produces a selective blockade of voltage operated calcium channels. Copyright © 2003 John Wiley & Sons, Ltd.