bluuebunny/crossref_metadata_2025_split huggingface dataset:
Electrical and mechanical properties of some polymeric composites
Authors: Mansour S. H. , Abd‐El‐Messieh S. L. 
Published: August 2002

AbstractTwo unsaturated polyester resins based on poly[propylene‐phthalate‐hexane‐maleate] (PE1) and poly[oxydiethylene‐phthalate‐hexane‐maleate] (PE2) were prepared and crosslinked with styrene monomer. The structure of the prepared polyesters was detected using IR and NMR. The thermal behavior of the styrenated polyesters was determined using differential scanning calorimetry. The dielectric properties for the PE1 and PE2 styrenated polyesters and their mixtures with different ratios were also studied with a frequency range of 100 Hz to 100 kHz at room temperature (≈25°C). The mixture containing a 50/50 ratio of PE1/PE2 possessed the most promising dielectric properties. Thus, this sample was chosen along with the two separate styrenated polyesters to be loaded with three different types of fillers: calcium carbonate, clay, and quartz. This investigation led to the conclusion that the sample containing 50/50 PE1/PE2 loaded with 60–70% clay possessed the most promising dielectric properties. The compressive and tensile strength values were also studied for PE1, PE2, and their 50/50 mixture filled with the three types of fillers with the recommended concentrations (60 and 70%). The results indicated that the quartz composite (60%) had the best mechanical properties with respect to the clay and calcium carbonate. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 83: 1167–1180, 2002
Preparation of biodegradable polyesters/high‐amylose‐starch composites by reactive blending and their characterization
Authors: Avella Maurizio , Errico Maria Emanuela , Rimedio Raffaello , Sadocco Patrizia 
Published: August 2002

AbstractTwo different biodegradable polyesters [polycaprolactone (PCL) and poly(3‐hydroxybutyrate‐co‐valerate) (PHBV)] were blended with a maize starch that had high amylose content through the use different reactive approaches. The compatibilization of both systems was obtained. PCL/starch composites were obtained by the addition of a third reactive component that was able to act as a coupling agent, and the reactive interface of PHBV/starch composites was improved during blending with an organic peroxide. Thermal, morphological, and mechanical characterization showed that the compatibilized composite materials had better final proprieties than neat materials or composites prepared without compatibilization. Finally, the degradation of all prepared materials by a compost simulation test was investigated. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 83: 1432–1442, 2002
Chitosan modified by poly(ethylene oxide): Film and mixture properties
Authors: Budtova Tatiana , Belnikevich Nina , Kalyuzhnaya Ljudmila , Alexeev Vladimir , Bronnikov Sergei , Vesnebolotskaya Svetlana , Zoolshoev Zoolsho 
Published: August 2002

AbstractChitosan + poly(ethylene oxide) mixtures and films prepared from these mixtures were studied by rheological, absorption of solvent vapors, SANS, and mechanical testing methods. At a stoichiometric chitosan:poly(ethylene oxide) monomer:monomer composition, the mechanical properties of chitosan + poly(ethylene oxide) film are the best as compared with those of the initial components or of other compositions. This film composition is shown to be less heterogeneous. Chitosan and poly(ethylene oxide) are proved to be slightly incompatible polymers. This is supposed to induce the two components to align and to order at their stoichiometric composition, leading to the improvement in the mechanical properties. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 84: 1114–1122, 2002; DOI 10.1002/app.10319
Environmental impact of antifouling technologies: state of the art and perspectives
Authors: Terlizzi A. , Fraschetti S. , Gianguzza P. , Faimali M. , Boero F. 
Published: August 2002

Abstract1. Marine fouling affects most man‐made surfaces temporarily or permanently immersed in the sea, resulting in significant (or substantial) economic costs. Intense research is aimed at preventing or reducing fouling.2. The most widespread solution to avoid fouling formation is to make surfaces unsuitable for settlers, coating them with antifouling (AF) paints containing toxic compounds. Most AF agents (e.g. tributyltin, (TBT)) have undesirable effects on non‐target species, including commercially important organisms.3. To date, the use of TBT in AF paints has been restricted (but not prohibited) in a number of countries and new biocides are in use.4. The environmental problems posed to marine systems by AF technologies are here briefly reviewed.5. New approaches focusing on alternatives to the use of biocidal AF paints are also considered and discussed. Copyright © 2001 John Wiley & Sons, Ltd.
Qualitative modelling for the development of a sustainable management strategy for the Peruvian scallop Argopecten purpuratus (Lamarck 1819)
Authors: Ortiz Marco , Wolff Matthias , Mendo Jaime 
Published: August 2002

Abstract

This study is the first attempt using Levins's Theory (loop analysis) in order to develop a sustainable management for the scallop, Argopecten purpuratus, fishery in Peru during El Niño‐Southern Oscillation events (ENSO) and upwelling conditions. Based on this theoretical framework, it was possible to estimate the local stability for each of these model systems and to follow the qualitative changes of the variables in response to external factors.
Based on our results, we suggest the following management policies to be implemented: (1) during ENSO events the size at the first capture of the scallops should be >70 mm and (2) the increase in the number of fishermen during ENSO events must be prevented. Both measures increase the sustainability of fishery under ENSO and upwelling conditions. The ecological models predict that during ENSO and upwelling events, any management strategy to increase the recruitment of the scallop would not have a positive impact on the adult stock.
Finally, we suggest that more efforts must be focused on the development of extended eco‐social models, which incorporate further social and economic variables, increasing realism of the abstractions for this fishery activity.
Copyright © 2002 John Wiley & Sons, Ltd.
Evidence that dopamine‐beta‐hydroxylase immunoreactive neurons in the lateral reticular nucleus project to the spinal cord in the rat
Authors: Lee Hyun S. , Waterhouse Barry D. , Mihailoff Greg A. 
Published: August 2002

AbstractThe existence of noradrenergic projections from the lateral reticular nucleus (LRt) to the dorsal quadrant of cervical, thoracic, or lumbar spinal cord was investigated using a combined method of WGA‐apo‐HRP‐gold retrograde tracing and dopamine‐beta‐hydroxylase (DBH) immunocytochemistry. Preliminary retrograde tracing studies indicated that LRt neurons projecting to cervical, thoracic, or lumbar spinal cord were characteristically located near the perimeter of the LRt. Double‐labeling experiments demonstrated that a portion of these peripherally‐located, spinal‐projecting neurons were DBH‐immunoreactive. Double‐labeled neurons were also located at the parvocellular division of the contralateral LRt in the thoracic injection cases. Double‐labeled neurons were not observed at the subtrigeminal division in cervical, thoracic, or lumbar injection case. The results suggest the possibility that the noradrenergic LRt‐spinal pathway might be involved in a variety of pain processing and cardiovascular regulatory functions in the rat. Anat Rec 263:269–279, 2001. © 2001 Wiley‐Liss, Inc.
Sound‐generating and ‐detecting motor system in catfish: Design of swimbladder muscles in doradids and pimelodids
Authors: Ladich Friedrich 
Published: August 2002

AbstractCatfishes have evolved a diversity of swimbladder muscles serving in the generation of different sounds and probably other acoustic functions. In order to find out if anatomical and acoustical differences are parallelled by fine structural differences, I examined the sonic muscles of the doradid Platydoras and the pimelodid Pimelodus by gross dissections and ultrastructural methods. In Platydoras, the sound‐generating (drumming) muscle (DM) inserts on a dorsal bony plate that vibrates the swimbladder. In pimelodids, the large DM attaches directly on the ventral surface of the swimbladder, whereas the small tensor tripodis muscle (TT) inserts on the rostral surface near the tripus, the most caudal Weberian ossicle. Fibers of all three muscles possess an extensive development of sarcoplasmatic reticulum (SR) in association with very thin myofibrils (MF) but differed widely in their arrangement. In Platydoras, ribbons of MFs are arranged radially around a central core. Mitochondria were found within the core and the peripheral sarcoplasm. Pimelodus does not have a differentiated core and the cross‐sectional area of DM‐MFs is about 15% larger as determined by stereological measurements. The TT possesses shorter sarcomeres and more mitochondria than DMs, which were primarily found between MFs. This suggests faster contraction properties and greater resistence to fatigue compared with sonic muscles. Data indicate that the higher amount of DM‐myofibrils in pimelodids might result in stronger muscle contractions and, presumably, in higher sound intensities. The fine structure of the TT reveals that contractions most likely prevent transmission of swimbladder vibrations to the inner ear via the Weberian ossicles during vocalization. Anat Rec 263:297–306, 2001. © 2001 Wiley‐Liss, Inc.
Roles of peritrophic membranes in protecting herbivorous insects from ingested plant allelochemicals
Authors: Barbehenn Raymond V. 
Published: August 2002

AbstractFour mechanisms by which peritrophic membranes (PMs) potentially protect herbivorous insects from ingested allelochemicals are reviewed: adsorption, ultrafiltration, polyanion exclusion, and the capacity of PMs to act as antioxidants. Most of the research on the protective roles of PMs against ingested allelochemicals has focused on their impermeability to tannins. Adsorption of tannins by the PMs in grasshoppers may limit their permeability, but ultrafiltration of tannin complexes in the caeca is an alternative explanation. Polyanion exclusion does not explain the impermeability of caterpillar PMs to tannins (polyphenolate anions). Ultrafiltration remains the most likely mechanism by which tannins, and other tested allelochemicals, are retained in the endoperitrophic space. Although the pores in PMs are too large to impede the passage of most free allelochemicals, large allelochemical complexes are retained. Such complexes form in the gut fluid of caterpillars between tannic acid, proteins, lipids, and polyvalent metal cations, and also in the gut fluid of grasshoppers (Melanoplus sanguinipes) between some amphiphilic allelochemicals (digitoxin) and surfactant micelles. Further work is needed to examine the role of PMs as antioxidants in vivo, such as their potential to bind catalytically‐active metal ions. Arch. Insect Biochem. Physiol. 46:86–99, 2001. © 2001 Wiley‐Liss, Inc.
Molecular evidence for two vitellogenin genes and processing of vitellogenins in the American cockroach, Periplaneta americana
Authors: Tufail M. , Hatakeyama M. , Takeda M. 
Published: August 2002

AbstractThe American cockroach, Periplaneta americana has two vitellins (Vn1 and Vn2) and corresponding vitellogenins (Vg1 and Vg2). Vns/Vgs were separated on the SDS‐PAGE as three major polypeptide bands [170, 100 (multisubunits), and 50 kD] and a minor polypeptide band (150 kD) both in the egg (mature terminal oocyte) extract and in the female hemolymph. We previously cloned one Vg (Vg1) cDNA and showed that the 170‐kD polypeptide originated from the C‐terminus of the Vg1. In the present study, we cloned the other Vg (Vg2) cDNA. It is 5,826 bp long encoding 1,876 amino acid residues (including 16 residues for putative signal peptide) in a single ORF. The deduced amino acid sequences of both Vgs (Vg1 and Vg2) of P. americana showed 30% identity. The GL/ICG motif is followed by eight cysteine residues at conserved locations near the C‐terminal and the DGXR motif starts 18 residues upstream of the GL/ICG motif. The chemically determined N‐terminal amino acid sequences of the 150‐kD and of the 50‐kD polypeptides matched exactly with each other and with the deduced N‐terminal amino acid sequence of the Vg2 cDNA. The pattern of processing in P. americana Vns/Vgs is discussed. Arch. Insect Biochem. Physiol. 48:72–80, 2001. © 2001 Wiley‐Liss, Inc.
Effects of calcium channel antagonists on the corpora allata of adult male loreyi leafworm Mythimna loreyi: Juvenile hormone acids release and intracellular calcium level
Authors: Hsieh Yi‐Chun , Hsu Err‐Lieh , Chow Ying‐Shing , Kou Rong 
Published: August 2002

AbstractThe effects of voltage‐dependent calcium channel (VDCC) antagonists and the non‐specific calcium channel antagonists on both juvenile hormone acids (JHA) release and cytosolic free calcium concentration ([Ca2+]i) are investigated in the corpora allata (CA) of the adult males loreyi leafworm Mythimna loreyi. The VDCC antagonists used in this study are: the L‐type antagonists diltiazem, nifedipine, and verapamil, the N‐type antagonist ω‐Conotoxin (CgTx) GVIA, the N‐ and P/Q‐type antagonist ω‐CgTx MVIIC, and the T‐type antagonist amiloride. The non‐specific calcium channel antagonists used in this study were cadmium (Cd2+), cobalt (Co2+), nickle (Ni2+), and lanthanum (La3+). The results show that both the DHPs‐sensitive L‐type antagonist nifedipine and the N‐type antagonist ω‐CgTx GVIA were able to inhibit JHA release, but only ω‐CgTx GVIA was able to reduce the [Ca2+]i. Among the non‐specific calcium channel antagonists, Cd2+ is the most potent in reducing JHA release but without obvious effect on the [Ca2+]i, La3+ significantly increases the [Ca2+]i but without effect on JHA release. Arch. Insect Biochem. Physiol. 48:89–99, 2001. © 2001 Wiley‐Liss, Inc.
Prompt magnetic investigations of archaeological remains in areas of infrastructure development: Israeli experience
Authors: Eppelbaum Lev V. , Khesin Boris E. , Itkis Sonya E. 
Published: August 2002

AbstractMagnetic prospecting is the most widely used method for the investigation of archaeological remains in the world. This method is often applied before and during various engineering exploration (e.g. road construction, preparing areas for various types of building) and areas of agricultural utilization. Taking into account an extremely high concentration of archaeological sites of different age at Israeli territory, prompt geophysical–archaeological assessment of areas allocated for engineering and agricultural utilization, is a necessary preliminary component of the design process. However, noise both of natural and artificial origin strongly complicates interpretation of observed magnetic anomalies. The most significant disturbing factors are oblique magnetization (magnetization vector in the Israeli territory is inclined about 45°), complex geological structure (presence of a variety of disturbing bodies) of investigated site, influence of rugged topography, as well as influence of modern iron‐containing objects. The non‐conventional procedures developed by the authors are intended for application in such complicated environments and include elimination of noise from various sources, selection of ‘useful’ anomalies against the noise background, qualitative and quantitative interpretation of anomalies and three‐dimensional physical–geological modelling. Effective integration of these procedures with other interpretation methods allowed rapid localization of tens of archaeological remains and their protection from unpremeditated destruction. Copyright © 2001 John Wiley & Sons, Ltd.
Suppression of autoimmune arthritis in interleukin‐1‐deficient mice in which T cell activation is impaired due to low levels of CD40 ligand and OX40 expression on T cells
Authors: Saijo Shinobu , Asano Masahide , Horai Reiko , Yamamoto Hiroaki , Iwakura Yoichiro 
Published: August 2002

AbstractObjectiveTo elucidate the roles of interleukin‐1 (IL‐1) in the development of 2 etiologically different rheumatoid arthritis (RA) models: the type II collagen (CII)–induced arthritis (CIA) model and the human T cell leukemia virus type I transgenic (HTLV‐I Tg) mouse model.MethodsFor the CIA model, DBA/1J‐background IL‐1α−/−, IL‐1β−/−, IL‐1α/β−/−, and wild‐type littermate mice were immunized with CII. For the HTLV‐I Tg model, BALB/c IL‐1β−/− or IL‐1α/β−/− mice were crossed with HTLV‐I Tg mice. The effects of IL‐1 deficiency were assessed as follows: Development of arthritis was assessed both macroscopically and microscopically. Serum antibody titer was measured by enzyme‐linked immunosorbent assay. Proliferative response of lymph node cells was assayed by measurement of 3H‐thymidine incorporation. Expression of T cell surface molecule CD40 ligand (CD40L) and OX40 was determined by multicolor flow cytometric analysis.ResultsThe development of arthritis was markedly suppressed in IL‐1α/β−/− mice in both models, although the effect was less prominent in HTLV‐I Tg mice. Deficiency of only IL‐1α or only IL‐1β was also associated with disease suppression. Antibody production after immunization with CII was normal in IL‐1α/β−/− mice, while autoantibody production was suppressed in IL‐1α/β−/− HTLV‐I Tg mice. In IL‐1α/β−/− mice, the T cell proliferative response against CII was greatly reduced in both the CIA and the HTLV‐I Tg models, suggesting inefficiency of T cell activation. Furthermore, expression of CD40L and OX40 on T cells was greatly reduced in IL‐1α/β−/− mice.ConclusionThese observations suggest that T cell activation by IL‐1 is important for the development of autoimmunity and arthritis in these mice.
Pharmacokinetics and protein binding of the selective neuronal nitric oxide synthase inhibitor 7‐nitroindazole
Authors: Bush Mark A. , Pollack Gary M. 
Published: August 2002

AbstractUtilization of nitric oxide (NO) synthase (NOS) inhibitors to probe the role of NO in various central nervous system processes requires use of an inhibitor selective for neuronal NOS, and is facilitated by knowledge of the pharmacokinetics of the inhibitor. The present project was undertaken to elucidate the disposition of the selective neuronal NOS inhibitor 7‐nitroindazole (7‐NI). A simple, specific HPLC assay was developed with requisite sensitivity to quantitate 7‐NI in serum after administration of pharmacologically relevant doses. Further experiments were performed to assess the effects of administered dose on 7‐NI disposition. 7‐NI displayed marked nonlinearity, consistent with saturable elimination, when administered by ip injection in peanut oil. The nonlinearity was related to total dose, but not to the concentration of 7‐NI in the vehicle. Binding of 7‐NI in rat serum was concentration‐independent and does not contribute to the nonlinearity. Various formulations for iv administration of this water‐insoluble compound were evaluated; the optimal vehicle, from the standpoint of 7‐NI solubility, appeared to inhibit the clearance of 7‐NI from the systemic circulation. Considering the nonlinear disposition of 7‐NI, knowledge of the pharmacokinetics of this inhibitor is requisite to designing administration protocols to achieve the desired magnitude and duration of NOS inhibition. Copyright © 2000 John Wiley & Sons, Ltd.
Folinic acid protects against suppression of growth by Methotrexate in mice
Authors: Perwaiz Iqbal M. , Sultana Fakhara , Mehboobali Naseema , Pervez Shahid 
Published: August 2002

AbstractThe objective of this study was to investigate whether folinic acid supplementation would protect young mice against suppression of growth by methotrexate (MTX). Four equal groups of Balb/c young male mice (5 animals in each group; mean±SD body weight 9.64±0.85 g, in their rapid growth phase) were subjected to the following drug treatment: One group was given MTX (3.5 mg/kg body weight) intraperitoneally on every 2nd day, another received folinic acid (7.0 mg/kg body weight) intraperitoneally every 2nd day. The third group was given both of these drugs (MTX on every 2nd day and folinic acid 8 h post‐MTX injection). The fourth group was injected with physiological saline every other day to serve as a control group. Total body weight, food and water consumption by animals in each group were monitored every second day for a period of 3 weeks. After this period mice were sacrificed and liver, spleen and kidneys were excised, weighed and analyzed for MTX and dihydrofolate reductase activity. A small segment of the proximal part of small intestine and small pieces of liver and kidney were also removed to study morphological changes.Compared to the groups, which received folinic acid alone, folinic acid plus MTX or physiological saline, mean increase in body weight (6.8±0.8 g) of mice over a period of 3 weeks was minimal in the group receiving MTX alone (one‐way ANOVA p=0.0001). The mean weights of liver and kidney in this group receiving MTX alone were also found to be significantly less than the mean weights of these organs in the 3 groups (p<0.001). The negative effect on growth of animals appears not only due to malabsorption but inhibition of pathway of de novo DNA synthesis may also be involved. This is supported by loss of villous pattern in small intestine of mice treated with MTX alone and increased accumulation of free MTX and decreased dihydrofolate reductase in the liver of the group receiving MTX alone as compared with the group receiving MTX plus folinic acid. The data indicate that the administration of folinic acid protects mice against suppression of growth by MTX. On the basis of these observations it can be deduced that patients suffering from juvenile rheumatoid arthritis or acute lymphoblastic leukaemia receiving MTX over a long period of time might be at a risk of experiencing short‐term suppression of growth, however they could benefit from supplementation with folinic acid. Copyright © 2001 John Wiley & Sons, Ltd.
Predicted SAR in sprague‐dawley rat as a function of permittivity values*†
Authors: Gajšek P. , Ziriax J.M. , Hurt W.D. , Walters T.J. , Mason P.A. 
Published: August 2002

AbstractSpecific absorption rate (SAR) value is dependent on permittivity value. However, variability in the published permittivity values for human and animal tissue and the development of sophisticated 3‐dimensional digital anatomical models to predict SAR values has resulted in the need to understand how model parameters (permittivity value) affect the predicted whole body and localized SAR values. In this paper, we establish the partial derivative of whole body SARs and localized SAR values (defined as SAR for individual organs with respect to a change in the permittivity values of all tissue types, as well as for those tissues with the most variable permittivity values. Variations in the published permittivity values may substantially influence whole body and localized SAR values, but only under special conditions. Orientation of the exposed object to the incident electromagnetic wave is one of the most crucial factors. Bioelectromagnetics 22:384–400, 2001. Published 2001 Wiley‐Liss, Inc.