bluuebunny/crossref_metadata_2025 huggingface dataset:
Familial cardioneuromyopathy with hyaline masses and nemaline rods: A novel phenotype
Authors: Selcen Duygu , Krueger Bruce R. , Engel Andrew G.
Published: August 2002

Two siblings (patients 1 and 2) had adult‐onset muscle weakness that was greater distally than proximally, as well as respiratory insufficiency, cardiomyopathy, and cervical spine anomalies. Electromyography studies indicated myopathy and findings consistent with neuropathy in both. In the deltoid muscle of patient 1 and the anterior tibial muscle of patient 2, myriad type 1 fibers harbored large, irregularly polygonal, and mostly central hyaline masses, small vacuoles, and nemaline rods flanking the hyaline masses or congregated under the sarcolemma. The hyaline masses are intensely congophilic; react strongly for desmin, αB‐crystallin, α1‐antichymotrypsin, and ubiquitin and variably for gelsolin and dystrophin; and are devoid of α‐actinin, nebulin, titin, and slow myosin. The presence of ubiquitin, gelsolin, and fragmented filaments, and the absence of nebulin, titin, α‐actinin, and slow myosin in the hyaline masses, signal nonlysosomal protein degradation. Ultrastructurally, the hyaline masses are composed of intermediate‐density amorphous material intermingled with fragmented filaments and irregularly branching, pleomorphic, highly electron‐dense material, resembling the hyaline structures of myofibrillar myopathy. We conclude that the pathological process in this syndrome is one that induces destruction of myofibrillar components, resulting in aggregation of the degraded residues in hyaline masses, and causes replication of Z disks, resulting in formation of nemaline rods.
Preliminary evidence for in vitro methylation of tributyltin in a marine sediment
Authors: Vella Alfred J. , Adami Jean Pierre Tabone
Published: August 2002

Recent reports from our laboratory on the occurrence of methylbutyltins in marine sediments and seawater suggest that these compounds are formed in the environment by the methylation of both tributyltin (TBT) and that­of its degradation products, i.e. dibutyltin and monobutyltin, to give MenBu(4−n)Sn for which n = 1, 2 and 3 respectively. We investigated the possibility of inducing methylation of TBT in seawater–sediment mixtures in experiments carried out in vitro using environmental materials collected from a yacht marina in Msida, Malta. Three water–sediment mixtures, which were shown to contain TBT, dibutyltin and monobutyltin but no other organotins, were spiked with tributyltin chloride (90 mg in 100 ml sea‐water/100 ml sediment); to one mixture was added sodium acetate and to another methanol, to act as possible additional carbon sources, and all mixtures were allowed to stand at 25 °C in stoppered clear‐glass bottles in diffused light for a maximum of 315 days. Speciation and quantification of organotins was performed using aqueous phase boroethylation with simultaneous solvent extraction followed by gas chromatography with flame photometric detection. The atmosphere inside the bottles quickly became reducing with abundant presence of H2S, and after an induction period of about 112 days, and only in the reaction mixture containing methanol, methyltributyltin (MeBu3Sn) was observed in both sediment (maximum concentration 0.87 µgSn g−1) and overlying water (maximum concentration 6.0 µgSn l−1). The minimum conversion yield of TBT into MeBu3Sn was estimated to be 0.3%. MeBu3Sn has a significantly lower affinity for sediment than TBT and, therefore, is more mobile in the marine environment, possibly also migrating into the atmosphere to generate a hitherto unsuspected flux of organotin into that phase. Copyright © 2001 John Wiley & Sons, Ltd.
Synthesis and properties of novel σ–π alternating polymers with triphenylamine and organosilicon units
Authors: Sakamaki Koichi , Ohshita Joji , Kunai Atsutaka , Nakao Hidenobu , Adachi Akira , Okita Koichi
Published: August 2002

We have synthesized novel σ–π conjugated polymers with N,N‐bis(p‐ethynylphenyl)‐N‐(p‐tolyl)amine as the π‐unit. The electroluminescent devices, with a double‐layer system composed of Alq and the present polymers as the emitting‐electron‐transporting and hole‐transporting layers respectively, emit green electroluminescence with a maximum intensity of 760 cd m−2. Copyright © 2001 John Wiley & Sons, Ltd.
New steroid‐group‐containing borazine compounds and their 13C NMR spectra
Authors: Yamashita Hiroshi , Koda Naoko , Murakami Teiichi , Uchimaru Yuko
Published: August 2002

New borazine compounds containing steroid units (cholesteryl and stigmasteryl) were prepared by the reactions of B,B′,B″‐trichloro‐N,N′,N″‐trimethylborazine with the 3‐chloro derivatives of the corresponding steroids under Grignard conditions. The products were characterized by 13C–1H correlation NMR measurements to give fully assigned 13C NMR data. Copyright © 2001 John Wiley & Sons, Ltd.
Amino‐acid hydroselenites: synthesis and cytotoxicity
Authors: Lukevics E. , Arsenyan P. , Rubina K. , Shestakova I. , Domracheva I. , Nesterova A. , Popelis J. , Pudova O.
Published: August 2002

Amino acids, di‐ and tri‐peptides readily react with selenic acid (H2SeO3, formed during solution of selenium(IV) oxide in water) to give the corresponding ammonium hydroselenites. Most selenites synthesized are very active (0.4–11 µg ml−1) against mouse hepatoma MG‐22A and readily increase NO concentration in the cultural medium on the HT‐1080 line (up to TG100 = 1500%). The amino‐acid hydroselenites studied influenced the cell phenotype. Copyright © 2002 John Wiley & Sons, Ltd.
Historical Review. Of garlic, mice and Gmelin: the odor of trimethylarsine
Authors: Chasteen Thomas G. , Wiggli Markus , Bentley Ronald
Published: August 2002

In the 19th century, rooms were frequently decorated with wallpaper containing arsenical pigments; illness and fatalities often resulted. In 1839, Leopold Gmelin described a mouse‐like odor under those conditions. Much later, it was recognized that the problem was the formation of toxic and volatile trimethylarsine by fungal action. Gmelin's observation was misreported as a garlic‐like odor that is characteristic of trimethylarsine. Gmelin's original article in German and an English translation are included, and possible explanations for the incorrect reporting and for the original observation are described. Copyright © 2002 John Wiley & Sons, Ltd.
The synthesis, characterization and polycondensation of metal‐containing diols: crystal structure of [(η5‐C5H5)(CO)2Fe(CH2)3O‐{2,6‐(CH2OH)2‐4‐CH3C6H2}]
Authors: Mapolie S. F. , Mavunkal I. J. , Moss J. R. , Smith G. S.
Published: August 2002

The synthesis of two new transition‐metal‐containing polyesters is described. The precursors are bifunctional organometallic monomers that were synthesized using 2,6‐bis(hydroxymethyl)‐p‐cresol as the key reagent. This was achieved by simple coupling reactions between the appropriate organometallic alkyl halide and the cresol reagent. Polycondensation reactions were carried out with terephthaloyl chloride using ambient temperature solution techniques. The new low molecular weight oligomeric polyesters were characterized using Fourier transform infrared and 1HNMR spectroscopy, differential scanning calorimetry, thermogravimetric analysis and size‐exclusion chromatography analyses. Copyright © 2002 John Wiley & Sons, Ltd.
Gas transport properties of a series of cardo polyarylethers
Authors: Wang Zhonggang , Chen Tianlu , Xu Jiping
Published: August 2002

Gas transport of H2, CO2, O2, N2, and CH4in a series of cardo polyarylethers were examined over a temperature range of 30 ∼ 100°C. These polymers include three poly(aryletherketone)s, two poly(arylethersulfone)s, and one poly(aryletherketoneketone). It was found that the large length/diameter ratio of the polymer repeat unit for cardo polyaryletherketoneketone (PEKK‐C) and strong intermolecular interaction in hydrogen‐bonded polyarylethersulfone (PES‐H) and hydrogen‐bonded polyaryletherketone (PEK‐H) resulted in a considerable increase in gas permselectivity. Alkyl‐substituted polyaryletherketone (PEK‐A), bearing a pendant bulky propyl group on the cardo ring, simultaneously exhibited 62.5% higher H2permeability and 59.8% higher H2/N2permselectivity than unmodified poly(aryletherketone) (PEK‐C). The causes of the trend were interpreted in terms of chain packing density, segmental motion ability, steric factor, and intermolecular interaction of polymers, together with gas kinetic diameter and critical temperature data. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 83: 791–801, 2002
Effects of crosslinking on thermal and mechanical properties of polyurethanes
Authors: Chiou Bor‐Sen , Schoen Paul E.
Published: August 2002

The effects of chemical crosslinking on the thermal and dynamic mechanical properties of a polyurethane system were examined. The polyurethanes were prepared from poly(propylene glycol), a diol; trimethylolpropane propoxylate, a triol; and poly(propylene glycol), tolylene 2,4‐diisocyanate terminated, a diisocyanate monomer. The crosslink density was controlled by varying the triol concentration from 10 to 70 mol % and the isocyanate‐to‐hydroxyl (NCO/OH) ratio from 1.0 to 1.3. All the samples had one glass‐transition temperature and no crystalline regions. In addition, there were larger increases in glass‐transition temperature over the range of triol concentrations studied than over the range of NCO/OH ratios studied. For all samples, the Dibenedetto equation relating glass‐transition temperature to extent of crosslinking fit the data very well. Also, samples with higher crosslink densities had much larger elastic moduli for temperatures above the glass‐transition temperature. By assuming the system was a phantom network, approximate crosslink densities for stoichiometric samples were obtained from the dynamic mechanical data and these agreed fairly well with theoretical predictions. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 83: 212–223, 2002
Chain‐extended polyurethane–acrylate ionomer for UV‐curable waterborne coatings
Authors: Yang Jianwen , Wang Zhiming , Zeng Zhaohua , Chen Yonglie
Published: August 2002

Conventional and chain‐extended UV‐curable waterborne polyurethane–acrylate (PUA) ionomers were prepared from diisocyanate, polyethylene glycol (PEG), dimethylolpropionic acid, and hydroxyethyl methacrylate, and identified with FTIR spectra and 500‐MHz 1H‐NMR spectra. The number‐average molecular weight (Mn) and polydispersity of chain‐extended PUA were determined by gel permeation chromatography. For the synthesis of chain‐extended PUA, water was employed as the chain extender. The two kinds of PUA prepolymer could be easily dispersed in water in the form of self‐emulsified latex after the carboxyl group attaching to the backbone of PUA was neutralized with tertiary amine. The effects of Mn of PEG, carboxyl content, and type of diisocyanate on the interfacial tension and rheological behavior of PUA dispersions were investigated. The chain‐extended PUA prepolymer could photopolymerize to a greater extent than the conventional PUA, as indicated by differential photocalorimetry. The photopolymerization kinetics of chain‐extended PUA, based on different substrates, were also investigated. The differential scanning calorimetry analysis for the photo‐cured films from PUA dispersions suggested that lower Mn of PEG tended to favor phase mixing between soft and hard segment phases, and higher Mn of PEG would provoke phase separation. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 84: 1818–1831, 2002; DOI 10.1002/app.10384
The kinetics of the thermal decomposition of poly(3‐hydroxybutyrate) and maleated poly(3‐hydroxybutyrate)
Authors: Chen Cheng , Fei Bin , Peng Shuwen , Zhuang Yugang , Dong Lisong , Feng Zhiliu
Published: August 2002

The thermal decomposition mechanism of maleated poly(3‐hydroxybutyrate) (PHB) was investigated by FTIR and 1H NMR. The results of experiments showed that the random chain scission of maleated PHB obeyed the six‐membered ring ester decomposition process. The thermal decomposition behavior of PHB and maleated PHB with different graft degree were studied by thermogravimetry (TGA) using various heating‐up rates. The thermal stability of maleated PHB was evidently better than that of PHB. With increase in graft degree, the thermal decomposition temperature of maleated PHB gradually increased and then declined. Activation energy Ea as a kinetic parameter of thermal decomposition was estimated by the Flynn‐Wall‐Ozawa and Kissinger methods, respectively. It could be seen that approximately equal values of activation energy were obtained by both methods. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 84: 1789–1796, 2002; DOI 10.1002/app.10463
The development of controllable complex curing agents for epoxy resins. II. Examining the dissociation and thermal behavior of transition metal‐diamine complex‐epoxy blends
Authors: Hamerton Ian , Hay John N. , Herman Henryk , Howlin Brendan J. , Jepson Peter , Gillies Duncan G.
Published: August 2002

A series of complexes incorporating diamine (o‐phenylene diamine and 2‐aminobenzylamine) ligands and containing the acetato and chloro salts of Ni(II) and Cu(II) was incorporated into two commercial epoxy resins recognized as industry standards (MY721 and MY750). The cure properties of the complexes are assessed alongside commercial curative systems. Thermal analysis (principally differential scanning calorimetry) shows that the nature of the cure mechanism can be dramatically affected by the nature of the transition metal and counterion (and the level of curing agent incorporation). For example, by using a nickel(II) acetato complex rather than its chloro analog, the onset of the cure reaction of MY721 may be reduced by 40 K. Thermogravimetric analysis, and visible, infrared, and electron spin resonance spectroscopy are employed to determine the point at which the complexes undergo dissociation. The data show that Cu(2‐ABA)2(ac)2 appear to dissociate at temperatures between 70 and 80°C in octan‐1‐ol. A multivariate approach is applied to the analysis of infrared data obtained for solvated complex samples subjected to a heating program and the results are consistent with the dissociation temperature obtained from the other spectral data. The data suggest that the aromatic amino function in the complex undergoes dissociation from the metal at a lower temperature than the aliphatic amine. The 2‐ABA‐based complexes containing chloride counterions undergo gelation at higher temperatures than their acetato analogs (for both commercial epoxy systems). The newly prepared complexes generally display ηmin values comparable with the commercial curative systems [the exceptions being Cu(2‐ABA)2Cl2 and Ni(OPD)3Cl2, which produce markedly higher values of 14 and 10 P, respectively], but it is believed that this is due to agglomeration and settling of the complex as the resin viscosity decreases during the heating cycle. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 84: 2411–2424, 2002
Surface modification of low‐density polyethylene films by UV‐induced graft copolymerization with a fluorescent monomer
Authors: Wu J. Z. , Kang E. T. , Neoh K. G. , Wu P.‐L. , Liaw D. J.
Published: August 2002

Surface modification of argon plasma–pretreated low‐density polyethylene (LDPE) film via UV‐induced graft copolymerization with a fluorescent monomer, (pyrenyl)methyl methacrylate (Py)MMA, was carried out. The chemical composition and morphology of the (Py)MMA‐graft‐copolymerized LDPE [(Py)MMA‐g‐LDPE] surfaces were characterized, respectively, by X‐ray photoelectron spectroscopy (XPS) and by atomic force microscopy (AFM). The concentration of the surface‐grafted (Py)MMA polymer increased with Ar plasma pretreatment time and UV graft copolymerization time. The photophysical properties of the (Py)MMA‐g‐LDPE surfaces were measured by fluorescence spectroscopy. After graft copolymerization with the fluorescent monomer, the surface of the LDPE film was found to have incorporated new and unique functionalities. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 80: 1526–1534, 2001
Synthesis of nylon 6,6 copolymers with aromatic polyamide structure
Authors: Wang Huei‐Hsiung
Published: August 2002

In this article, flexible nylon 6,6 was reinforced with rigid‐chain aromatic polyamides based on poly(4,4′‐diphenylsulfone terephthalamide) (PSA), poly(p‐diphenyl oxide terephthalamide) (POA), poly(p‐diphenylmethane terephthalamide) (PMA), and isophthaloyl chloride (IPC). Various high molecular weight block copolyamides were synthesized by solution polymerization using p‐aminophenylacetic acid (p‐APA) as a coupling agent. Their thermal properties show that the block copolyamides exhibit higher values of Tg and Tm and better thermal stability than those of nylon 6,6, especially the IPC‐modified nylon 6,6. The order of increased thermal properties of copolyamides is IPC > POA > PMA > PSA. From wide‐angle X‐ray diffraction patterns, it was found that nylon 6,6 has two diffraction peaks, that is, 2θ = 20.5° and 23°, while the multiblock copolymers showed only one at 2θ = 20°, indicating a different crystal structure. It was found that the mechanical properties of the IPC‐modified nylon 6,6 were improved more than those of the semirigid copolyamides. The order of tensile strength was IPC > PSA > PMA > POA, but for elongation, it was POA > PMA > PSA > IPC. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 80: 2167–2175, 2001
Characterization and application of high magnetic property chitosan particles
Authors: An Xiaoning , Su Zhixing
Published: August 2002

High magnetic property chitosan particles were prepared from chitosan coated on magnetic powder, glutaraldehyde modified, and then epichlorohydrin crosslinked. The magnetic properties, the surface, and the morphology of the magnetic particles were characterized. An optimum condition of immobilization of aprotinin on magnetic particles was obtained, then these particles were used for affinity purification of trypsin, and the condition of affinity purification was discussed. The proposed method was successfully applied to the purification of trypsin. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 81: 1175–1181, 2001
A novel determination technique of polymer viscosity‐average molecular weights with flow piezoelectric quartz crystal viscosity sensing
Authors: Mao Youan , Wei Wanzhi , Zhang Jinzhong , Li Yijin
Published: August 2002

A new method for the determination of polymer viscosity‐average molecular weights was developed with flow piezoelectric quartz crystal (PQC) viscosity sensing. The experimental setup with a 9 MHz AT‐cut quartz crystal and a flow detection cell was constructed and shown to be able to give highly reproducible data under the temperature of 25 ± 0.1°C and the fluid flow rate of 1.3–1.6 mL/min. A response model for PQC in contact with dilute polymer solutions (concentration <0.01 g/mL) was proposed in which the frequency change from the pure solvent, Δfs, follows Δfs = −k6ηl1/2 + k7, where ηl is the absolute viscosity of dilute polymer solution and k6 and k7 are the proportionality constants. This model was examined with poly(ethylene glycol) samples (PEG‐20000 and PEG‐10000) under the aforementioned experimental conditions using water as solvent. The result was Δfs = −1587ηl1/2 + 1443. Based on this model, the method for the determination of polymer viscosity‐average molecular weights, Mη, by flow PQC viscosity sensing was described and examined with an unknown poly(vinyl alcohol) (PVAL) sample. The new method proved to be an attractive and promising alternative for the determination of polymer molecular weights based on the good agreement between the molecular weight determined by the new method (Mη = 58600) for the unknown PVAL sample with that determined by the conventional capillary viscosity method. The new method has some advantages over the conventional viscosity method; for examples, operation is simpler and more rapid; the instruments required are cheaper and portable; the needed sample quantity is smaller; and the experimental setup constructed can be used in continuous measurement. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 82: 63–69, 2001
High dielectric constant composites based on metallophthalocyanine oligomer and poly(vinylidene fluoride‐trifluoroethylene) copolymer
Authors: Xu Haisheng , Bai Yi , Bharti Vivek , Cheng Z.‐Y.
Published: August 2002

Using a solution casting method, a high dielectric constant composite based on a copper‐phthalocyanine (CuPc) oligomer and a poly(vinylidene fluoride‐trifluoroethylene) copolymer is developed. The experimental data show that the low field dielectric constant of the composites (with 55 wt % CuPc) can reach 1000 and the loss is ∼0.5 at room temperature and 100 Hz. Because of the long‐range electron delocalization in CuPc, which results in a strong space charge response of the composite to the external field, there is a strong frequency dispersion of the dielectric properties. In addition, the dielectric properties exhibit a nonlinear behavior with electric field. At a field of 10 kV/cm, the dielectric constant at 10 Hz reaches 4500; meanwhile the dielectric loss is also high. One of the unique attributes of the composite is its mechanical properties that remain very much the same as those of the polymer matrix. Even for a composite with 55 wt % CuPc (the volume fraction of CuPc in the composite is also in the similar range), the composite film is still flexible, with a Young's modulus of 1.2 GPa at room temperature. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 82: 70–75, 2001
Caffeine selectivity of divinylbenzene crosslinked polymers in aqueous media
Authors: Villamena Frederick A. , De La Cruz Armah A.
Published: August 2002

The selective binding of caffeine to polymers is of interest in developing caffeine‐specific sensors. The influence of the nature and quantity of crosslinking agents and functional monomers on the selectivity and binding affinity of a polymer to caffeine is reported. A high binding affinity and selectivity of divinylbenzene (DVB) crosslinked polymers toward caffeine was exhibited by the binding competition of caffeine with several dimethylated and chlorinated xanthines and N‐methylated uric acids in aqueous media. To understand the nature of the caffeine–polymer interaction, we performed binding studies with solvents of different polarities and ionic strengths. The binding properties of DVB‐based polymers containing different functional monomers were compared with Amberlite® XAD resins. Analytes with hydrophilic and electron‐withdrawing groups lowered their binding affinity with the polymer in comparison with caffeine and its dimethylated derivatives. The caffeine–polymer interaction appeared to be predominantly a hydrophobic π–π interaction but partly due to the presence of caffeine‐specific sites. The reversibility of the caffeine–polymer binding was investigated, and the dissociation constants were approximated to be 27 and 6 mM. Dipole moments of caffeine and related molecules were estimated theoretically and were correlated with their corresponding B/T ratio, which is defined as the fraction of caffeine bound to the polymer. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 82: 195–205, 2001
Mill processability of brominated isobutylene‐co‐paramethylstyrene and its blends with EPDM
Authors: Kumar Bhuwneesh , De P. P. , De S. K. , Bhowmick A. K. , Peiffer D. G.
Published: August 2002

Milling behavior of brominated isobutylene‐co‐paramethylstyrene (BIMS) and its blends with ethylene propylene diene terpolymer (EPDM) rubber, was investigated over a range of temperatures and friction ratios in a drop mill operation. BIMS showed striking changes, that is, from a loose nervy band to a tight elastic band, as the temperature of the rolls was increased from 30°C to 90°C. For EPDM a loose band was observed at all temperatures and friction ratios studied. For the blends of BIMS and EPDM, the milling behavior changed from a tight elastic band to a loose bagging band on increasing the EPDM content. The critical nip gap (CNG), at which the front‐to‐back roll (F–B) transition occurred, was also measured. BIMS showed a much higher value of CNG than that of EPDM, indicating that the former had a significantly higher tendency for F–B transition than the latter material. For different blends of BIMS and EPDM, the CNG decreased on increasing the EPDM content, indicating a decrease in the tendency for F–B transition. The results were explained in terms of the rubber‐to‐metal adhesion and the viscosity of the polymers. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 82: 1483–1494, 2001
Polyimide surface modification by pulsed ultraviolet laser irradiation with low fluence
Authors: Lu Qing‐Hua , Li Mei , Yin Jie , Zhu Zi‐Kang , Wang Zong‐Guang
Published: August 2002

Surface modification on a polyimide film by pulsed ultraviolet (UV) laser irradiation with a fluence below its ablation threshold was studied by X‐ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM), and UV‐vis spectroscopy. It was observed that a photochemical reaction occurred and hydrophilic groups, such as —OH and —COOH, formed on the polyimide surface after irradiation. In addition, a ripple microstructure formed on the surface when the angle of incidence of the laser beam was 20–50o. The contact angle of the polyimide surface with water decreased and the adsorption ability of the surface to a water‐soluble dye clearly increased after laser irradiation. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 82: 2739–2743, 2001
Effects of silicone oil and polymeric modifiers on the mechanical properties of highly filled LLDPE
Authors: Zhu Song , Zhang Yong , Zhang Yinxi
Published: August 2002

The effects of coupling agents, silicone oil, and three types of polymeric modifiers on the mechanical properties of linear low density polyethylene (LLDPE) composites highly filled with aluminium hydroxide [Al(OH)3] were studied. Polymeric modifiers that contain polar groups, such as silane‐grafted polyethylene (Si‐g‐PE) and acrylic‐acid‐grafted ethylene‐vinyl acetate copolymer (AA‐g‐EVA), improve the mechanical properties dramatically, while nonpolar modifiers improve them to some extent. When Al(OH)3 was treated using a titanate coupling agent, the silicone oil increased the impact strength and elongation at break of the LLDPE/Al(OH)3 composites. Introduction of a polymeric modifier containing polar groups destroys the beneficial effects of silicone oil on film mechanical properties, while the introduction of a nonpolar elastomeric polymeric modifier retains the high impact strength and elongation at break. SEM analyses provide the indirect evidence of the encapsulation of silicone oil around the filler. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 83: 121–128, 2002
Evidence for the recent extinction of two Arctic charr Salvelinus alpinus (L.) populations in the West of Ireland
Authors: Igoe F. , O'Grady M. , Byrne C. , Gargan P. , Roche W. , O'Neill J.
Published: August 2002

1. This paper highlights the recent extinctions of two native Arctic charr populations in the West of Ireland, one population from the Lough Conn catchment, and a second from the Lough Corrib catchment, respectively.

2. The distribution of charr populations in the two catchments is reviewed. The current distribution information is drawn from recent fish stock surveys (Lough Corrib in 1996, and Lough Conn in 1997 and 1998). Previous records of charr in the literature and unpublished data are described to place the current distribution of charr within these catchments into a historical perspective.

3. The importance of the charr population in Lough Mask (Lough Corrib catchment) is emphasized, as it is one of the last extant examples of charr from a large Irish alkaline lake.

4. Impacts on charr populations in both catchments are discussed and conservation measures proposed. Copyright © 2001 John Wiley & Sons, Ltd.
Community participation in conserving and managing inland waters
Authors: Williams W.D.
Published: August 2002

Many international and national bodies have stressed the need for community participation in the conservation and management of inland waters. Community participation is needed for three basic reasons: to implement management measures difficult to enforce without community support; to act as a mechanism in protecting inland waters through support of conservation bodies; and, through voluntary actions, to monitor, restore and rehabilitate inland water‐bodies.

It is important to conserve and manage inland waters because of their many values and uses. To participate fully in conservation and management measures, the community needs to (a) recognize the importance of inland waters as a part of the global hydrological cycle, (b) have some knowledge of the nature and effects of major human impacts on inland waters, and (c) be aware of certain legal issues.

The ‘community’ is heterogeneous in nature but community groups of similar interest can be recognized. They vary from small, local action groups, through national groups to international bodies. They provide advice to and support government actions; others oppose and seek to change government actions. Community involvement can be at various levels, from the relatively inactive to the vigorously proactive.

Environmental education of the community should begin in childhood, continue at school and other educational institutions, and last throughout life. Information on the conservation and management of inland waters is available from many sources, but a powerful, modern source is the World Wide Web.

Four case studies are discussed with particular reference to community participation: Lake Washington and Mono Lake in the US (successful outcomes), the Aral Sea in central Asia and Lake Pedder in Australia (unsuccessful outcomes).

Copyright © 2002 John Wiley & Sons, Ltd.
Functional overexpression of wild‐type p53 correlates with alveolar cell differentiation in the developing human lung
Authors: Tebar Maria , Boex Joost J.M. , Ten Have‐Opbroek Ank A.W.
Published: August 2002

At 15 weeks after conception (a.c.), the human pulmonary acinus is lined by distal low‐columnar and more proximal cuboidal cells that are successive stages in alveolar type II cell differentiation (pseudoglandular period of lung development). From 16 weeks a.c. onward, there are also 'flatter' cells that are intermediate stages in the differentiation of cuboidal type II cells into squamous type I cells (canalicular period). We investigated the role of wild‐type p53 protein and the proliferation marker Ki‐67 in the differentiation of type II and type I cells in these two periods. Serial sections from fetal lungs (n = 30) were immunoincubated with antibodies against p53 and Ki‐67. The presence of prospective type II and type I cells was confirmed using immunohistochemistry for surfactant protein SP‐A as a differentiation marker and light and electron microscopy. The p53 and Ki‐67 positive nuclei were quantified per alveolar cell phenotype (i.e., low‐columnar; cuboidal; flatter). The occurrence of cell apoptosis was studied using propidium iodide (PI) and 4′,6′‐diamino‐2‐phenylindol dihydrochloride (DAPI) staining. The combined increase in p53 expression and decrease in Ki‐67 expression during alveolar epithelial cell differentiation suggests that wild‐type p53 protein plays a role in the differentiation of alveolar type II and type I cells in the human lung, and that this function is mediated through cell cycle arrest. The rare incidence of apoptotic nuclei in alveolar type II cells, together with their absence in alveolar type I cells, supports the view that p53 is involved in the differentiation, rather than the death, of alveolar epithelial cells. Anat Rec 263:25–34, 2001. © 2001 Wiley‐Liss, Inc.
Garlic prevents ultrastructural alterations caused by dehydration in mouse cerebral microvessels
Authors: Fahim Mohamed A. , El‐Sabban Farouk F.
Published: August 2002

Dehydration is known to significantly reduce both the time required for the first platelet aggregate and the time to full occlusion in photochemically‐induced thrombosis, in vivo. Ultrastructural changes that contribute to such events remain unknown. Therefore, the effect of water deprivation for 24 hr, (as a model for dehydration) on the ultrastructure of mouse pial microvessels was investigated. The possible beneficial effect of garlic in preventing such ultrastructural changes was also investigated. Four groups of TO strain: control, control‐garlic treated, dehydrated, and dehydrated‐garlic treated male mice, 10/group, were used. Dehydration was induced by water deprivation for 24 hr. Garlic solution was i.p. injected at 0.1 ml/10g body weight. In urethane‐anesthetized (2 mg/g, i.p.) mice, topical and transvessel bimodal fixation of pial microvessels was done with a phosphate buffered mixture of glutaraldehyde and paraformaldehyde, followed by a conventional electron microscopy procedure. Examination of control cerebral pial microvessels showed no evidence of cellular damage. Membranes of endothelial cells were intact. Within pial microvessels there was no evidence of platelet aggregation. Garlic treatments did not cause any ultrastructure abnormalities in control mice. Compared with control, dehydration caused the appearance of thrombi that consisted of platelet aggregates. Discoid platelets containing granules, spheroid degranulated platelets, and those with large pseudopodia were present in 80% of dehydrated mice. The venular endothelial surface of dehydrated mice revealed dilated profiles of endoplasmic reticulum and variously shaped vacuoles. Swelling of nuclear envelopes and mitochondrial distension were also present in dehydrated mice. Concomitant garlic treatment prevented most of these ultrastructural changes. These findings demonstrated the extent of damage to the pial microvessels in response to water deprivation and demonstrated the beneficial effect of garlic as a possible mean of protection against oncoming vascular pathology. Anat Rec 263:85–90, 2001. © 2001 Wiley‐Liss, Inc.
A letter from the executive editor
Authors: Stanley David W.
Published: August 2002

Colleagues,

One of the attractions of the position of Executive Editor is the opportunity to consider creative and experimental approaches to publishing findings from research on the frontiers of insect science. In future issues of Archives, we will be more active in publishing special issues. On one hand, we will continue working to publish special issues emerging from symposia presentations at scientific meetings. With cooperation from reviewers and from the publisher, we can arrange expedited reviews and rapid publication of issues that will appear in a timely manner relative to symposia presentations. On the other hand, we are also experimenting with Special Topics Issues, to appear no more than once each year. For these issues, papers from previous volumes of Archives will be published as a set of articles devoted to a single topic. The topics will emphasize research opportunities that are emerging or perhaps re‐emerging on the horizons of our field.

For this first Special Topics Issue, we have collected several papers devoted to insect cell culture. Studies of insect cell culture enjoy a lengthy history, dating back to the 1930’s when the practical goal of culturing insect cells related to research on insect‐borne viruses. In the years since this early work, we have seen marvelous progress in cell culture techniques and in the use of cell cultures to forge important advances in basic and applied research. The papers in this Special Topics Issue highlight some of the contemporary research with insect cell cultures, including analysis of an ion transport peptide, studies of glandular secretion, interactions of hormones and cells, the influence of an insect growth regulator on insect cells and activation of cellular immunity. We see, also, that basic work on cellular nutrition continues to yield important insights. It is hoped that Special Topics Issues will help facilitate further research. We welcome your suggestions for future Special Topics Issues.

In another innovative experiment in publishing, we have an opportunity to help bolster the careers of our colleagues in postdoctoral positions. As we all know, the postdoctoral phase of careers in insect science is growing in length and in the numbers of postdoctoral scientists. We invite nominations from mentors of active postdoctoral scientists (who have not yet accepted a permanent professional position), who may benefit from the experience of developing a sole‐authored mini‐review centered around their current research investigations. We are now developing guidelines for mini‐reviews, which will undergo the standard scrutiny of anonymous peer review. As always, your comments, and certainly your manuscripts are welcome. We look forward to working with you on these new initiatives.
Regulation of hexokinase in a freeze avoiding insect: Role in the winter production of glycerol
Authors: Muise Aleixo M. , Storey Kenneth B.
Published: August 2002

Hexokinase from larvae of the freeze‐avoiding goldenrod gall moth, Epiblema scudderiana, was purified 20‐fold using chromatography on DE52 Sephadex, phosphocellulose, and blue dextran. Final specific activity was 75.8 U/mg and SDS‐PAGE gave a molecular weight of 94,000 for the monomer. Arrhenius plot showed a break at 16° or 12°C in the absence vs. presence of 10% v/v glycerol, indicating a conformational change in the enzyme at lower temperatures but suggesting a stabilizing effect of glycerol. Comparison of hexokinase kinetic properties at 22° and 4°C showed higher affinity for both glucose and ATP (Km values were 45–50% lower), as well as for the cofactor Mg2+, at the lower temperature. Furthermore, product inhibition by glucose‐6‐phosphate and ADP was reduced at 4°C. Glucose levels rise in E. scudderiana as an apparent by‐product of high rates of glycogenolysis during glycerol synthesis. The temperature‐dependent properties of hexokinase would facilitate the recycling of this glucose back into the pathway of glycerol synthesis and could help to achieve the near stoichiometric conversion of glycogen to glycerol that is seen during cold hardening. Arch. Insect Biochem. Physiol. 47:29–34, 2001. © 2001 Wiley‐Liss, Inc.
The origin and functions of the insect peritrophic membrane and peritrophic gel
Authors: Terra Walter R.
Published: August 2002

There is a a fluid (peritrophic gel) or membranous (peritrophic membrane, PM) film surrounding the food bolus in most insects. The PM is composed of chitin and proteins, of which peritrophins are the most important. It is proposed here that, during evolution, midgut cells initially synthesized chitin and peritrophins derived from mucins by acquiring chitin‐binding domains, thus permitting the formation of PM. Since PM compartmentalizes the midgut, new physiological roles were added to those of the ancestral mucus (protection against abrasion and microorganism invasion). These new roles are reviewed in the light of data on PM permeability and on enzyme compartmentalization, fluid fluxes, and ultrastructure of the midgut. The importance of the new roles in relation to those of protection is evaluated from data obtained with insects having disrupted PM. Finally, there is growing evidence suggesting that a peritrophic gel occurs when a highly permeable peritrophic structure is necessary or when chitin‐binding molecules or chitinase are present in food. Arch. Insect Biochem. Physiol. 47:47–61, 2001. © 2001 Wiley‐Liss, Inc.
Cytoskeleton elements mediate the inhibition of the (Na++K+)atpase activity by PKC in Rhodnius prolixus malpighian tubules during hyperosmotic shock
Authors: Caruso‐Neves Celso , Silva Ian Victor , Morales Marcelo Marcos , Lopes AnÍBal Gil
Published: August 2002

In a previous paper, we observed that the specific activity of (Na++K+)ATPase of the isolated Malpighian tubules from Rhodnius prolixus is inhibited by protein kinase C (PKC) during hyperosmotic shock [Arenstein et al., J Membr Biol 146:47–57 [1995]; Caruso‐Neves et al., Z Naturforsch 53c:911–917 [1998]). In the present paper, we study the involvement of the cytoskeleton in this process using isolated Malpighian tubules of Rhodnius prolixus. We observed that pre‐incubation of the Malpighian tubule cells in hyperosmotic media decreases the specific activity of (Na++K+)ATPase by 90%. This effect was completely reversed when colchicine, which disrupts microtubules, or cytochalasin B, an inhibitor of actin microfilament polymerization, were added to the media in a dose‐dependent manner. The maximal reversion was obtained with colchicine 7.0 μM or cytochalasin B 5.0 μM. The simultaneous addition of sphingosine 50 ng/mL, an inhibitor of PKC, to 10 μM colchicine or 5 μM cytochalasin B, in hyperosmotic media, did not change the stimulatory effect of these drugs on the specific activity of (Na++K+)ATPase. On the other hand, the co‐incubation of TPA 20 ng/mL, an activator of PKC, to colchicine or cytochalasin B within hyperosmotic media, abolished the stimulatory effect of these drugs on the specific activity of (Na++K+)ATPase to a similar extent as hyperosmotic shock. These results suggest that inhibition of the (Na++K+)ATPase of the isolated Malpighian tubules from Rhodnius prolixus by PKC during hyperosmotic shock is mediated by cytoskeletal elements. Arch. Insect Biochem. Physiol. 48:81–88, 2001. © 2001 Wiley‐Liss, Inc.
Nitric oxide: An unconventional messenger in the nervous system of an orthopteroid insect
Authors: Bicker Gerd
Published: August 2002

Nitric oxide (NO) is a membrane‐permeant messenger molecule generated from the amino acid L‐arginine. NO can activate soluble guanylyl cyclase leading to the formation of cyclic GMP (cGMP) in target cells. In the nervous system, NO/cGMP signalling is thought to play essential roles in synaptic plasticity during development and also in the mature animal. This paper examines biochemical, cell biological, and physiological investigations of NO/cGMP signalling in the nervous system of the locust, a commonly used neurobiological preparation. Biochemical investigations suggest that an identical enzyme is responsible for both NO synthase (NOS) and NADPH‐diaphorase activity after tissue fixation. Immunocytochemical staining of an olfactory center in the locust brain shows that NOS‐immunoreactivity colocalizes with NADPH‐diaphorase at the cellular level. The cytochemical staining of NO donor and target cells in adult animals suggests functions in olfaction, vision, and sensorimotor integration. During development, NO is implicated in axonal outgrowth and synaptogenesis. The cellular distribution of NO‐responsive cells in neural circuits reflects potential functions of NO as a retrograde synaptic messenger, as an intracellular messenger, and as a lateral diffusible messenger independent of conventional synaptic connectivity. Arch. Insect Biochem. Physiol. 48:100–110, 2001. © 2001 Wiley‐Liss, Inc.
Distinctive hydrocarbons of the black dump fly, Hydrotaea aenescens (Diptera: Muscidae)
Authors: Carlson David A. , Bernier Ulrich R. , Hogsette Jerome A. , Sutton Bruce D.
Published: August 2002

Hydrotaea aenescens (Wiedemann), the black dump fly, is a potential biological control agent originally from the western hemisphere, now found in many parts of the Palearctic region except for the United Kingdom, where it cannot be imported for any reason. A complication of classical biological control is the problem of strain identification, as one must be able to somehow mark or follow a particular strain that has been introduced into the field or is contemplated for release. Gas chromatographic analysis of the surface hydrocarbons of pooled and individual dump fly adults resulted in reproducible hydrocarbon patterns that differentiated widely distributed strains of H. aenescens and showed similarities between strains that were related. Sexual dimorphism was observed in the surface hydrocarbons. Conspecific similarities included identities of the hydrocarbons found in colony material collected worldwide, with differences being found in the quantities of compounds present. Arch. Insect Biochem. Physiol. 48:167–178, 2001. Published 2001 Wiley‐Liss, Inc
Analysis of an insect neuropeptide, Schistocerca gregaria ion transport peptide (ITP), expressed in insect cell systems
Authors: Pfeifer T. A. , Hegedus D. , Wang Y.‐J. , Zhao Y. , Meredith J. , Brock H. W. , Phillips J. E. , Grigliatti T. A. , Theilmann D. A.
Published: August 2002

We have produced an active form of Schistocerca gregaria ion transport peptide (ITP) in an insect cell expression system. Transformed Drosophila Kc1 cells secreted a form of ITP into the cell culture medium that was proteolytically cleaved correctly at the amino (N)‐terminus. Concentrated culture supernatant from transformed Kc1 and Hi5 cells had high biological activity when tested on isolated locust ilea. Conversely, ITP expressed by baculovirus‐infected Sf9 cells was larger in size and had decreased specific activity compared to ITP produced by Kc1 cells due to incorrect cleavage of the peptide at the N‐terminus in the baculovirus system. This demonstrates how processing of the secreted foreign protein (ITP) expressed under the late polyhedrin promoter is compromised in a baculovirus‐infected cell. Transient transformation of Kc1 cells results in supernatants containing two forms of ITP; one form (A) co‐elutes with synthetic ITP and the other form (B) has reduced electrophoretic mobility. In contrast, in stably transformed Kc1 cell supernatant, ITP is expressed in a single form, which has the same electrophoretic mobility and specific biological activity as form A produced by transiently transformed Kc1 cells. Arch. Insect Biochem. Physiol. 42:245–252, 1999. © 1999 Wiley‐Liss, Inc.
Hormonal regulation of actin and tubulin in an epithelial cell line from Chironomus tentans
Authors: Fretz A. , Spindler K.‐D.
Published: August 2002

The morphogenetic changes in an epithelial cell line from Chironomus tentans that are evoked by molting hormones and molting hormone agonists are accompanied by transient changes in the concentration of actin and β‐tubulin protein and mRNA. As compared to controls, actin protein and mRNA concentrations increase by about 50%, whereas tubulin reaches maxima of 100% increase. The proportion between globular and filamentous actin remains constant after hormone treatment. Arch. Insect Biochem. Physiol. 41:71–78, 1999. © 1999 Wiley‐Liss, Inc.
Interleukin‐1α expression in capillaries and major histocompatibility complex class I expression in type II muscle fibers from polymyositis and dermatomyositis patients: Important pathogenic features independent of inflammatory cell clusters in muscle tissue
Authors: Englund Pernilla , Nennesmo Inger , Klareskog Lars , Lundberg Ingrid E.
Published: August 2002

Objective

To address the hypothesis that endothelial cells and/or muscle fibers are primary targets in the disease process by analysis of muscle tissue from patients with polymyositis (PM) and dermatomyositis (DM).

Methods

We included patients with laboratory signs and clinical symptoms typical of myositis, but without detectable infiltration of clusters of inflammatory cells in their muscle biopsy samples. An immunohistochemical technique was applied to identify CD3, CD68, lymphocyte function–associated antigen 1α, CD11b, very late activation antigen 4, endothelium 4, interleukin‐1α (IL‐1α), intercellular adhesion molecule 1, vascular cell adhesion molecule 1, IgG, IgM, IgA, and HLA–A/B/C in muscle tissue. Fiber type was defined by ATPase staining.

Results

IL‐1α expression was detected in endothelial cells of capillaries to a greater extent in patients than in controls, and class I major histocompatibility complex (MHC) expression was significantly increased in muscle fibers. We also observed that class I MHC expression was mainly confined to type II muscle fibers.

Conclusion

Our findings imply that defined molecular changes of blood vessels and muscle fibers are both independent of adjacent inflammatory infiltrates and could thus be primary events in the development of myositis. Moreover, both IL‐1α and class I MHC molecules might be important for the development of clinical symptoms in PM and DM patients.