bluuebunny/crossref_metadata_2025 huggingface dataset:
Ancient DNA as a multidisciplinary experience
Authors: Cipollaro M. , Galderisi U. , Di Bernardo G.
Published: June 2004

Investigation into DNA from archeological remains offers an inestimable tool for unraveling the history of humankind. However, a series of basic and technical difficulties renders the analysis of ancient DNA (aDNA) molecules troublesome, depending either on their own peculiar characteristics or on the complexity of processes affecting the bone matrix over time, all compromising the preservation of ancient DNA. This review underlines the contribution of many different disciplines, in particular molecular biology and genetics, to overcome these obstacles. The role of each expertise is illustrated to appropriately address the questions arising in aDNA investigations. © 2004 Wiley‐Liss, Inc.
Transvaginal color Doppler sonography for predicting response to concurrent chemoradiotherapy for locally advanced cervical carcinoma
Authors: Alcázar Juan Luis , Castillo Gerardo , Martínez‐Monge Rafael , Jurado Matías
Published: June 2004

Purpose

This study was conducted to evaluate the potential role of transvaginal color Doppler sonography (TVCD) in predicting response to concurrent chemoradiotherapy for locally advanced cervical cancer.

Methods and Materials

Tumor vascularity was assessed using TVCD before the start of concurrent chemoradiotherapy in 21 patients (median age, 47 years; range, 31–75 years) with histologically proven locally advanced cervical cancer. The lowest resistance index (RI), lowest pulsatility index (PI), and highest peak systolic velocity (PSV) from central vessels within the tumor were recorded and used for analysis. All patients were clinically evaluated by physical examination and CT scanning after completing the chemoradiotherapy protocol. Complete clinical response (CR) was determined when no residual tumor was found. Partial clinical response (PR) was determined when the tumor volume had decreased more than 50%.

Results

CR was achieved in 11 patients (52%), whereas 10 (48%) had PR. The initial median tumor volume was not statistically different between those with CR (26 cm3) and those with PR (28 cm3) (p = 0.71). RI was higher in those tumors with CR (median, 0.47) than in those with PR (median, 0.29) (p < 0.01). Likewise, PI was higher in tumors with CR (median, 0.81) than in those with PR (median, 0.41) (p < 0.01). No differences were found in PSV. The likelihood ratio for CR for tumors with a lowest RI of 0.35 or more was 2.7 (95% confidence interval, 1.8–3.6) and the likelihood ratio for CR for tumors with a lowest PI of 0.45 or more was 3.3 (95% confidence interval, 2.1–4.5).

Conclusions

The results suggest that TVCD may be useful in predicting clinical response to concurrent chemoradiation in patients with locally advanced cervical cancer. © 2004 Wiley Periodicals, Inc. J Clin Ultrasound 32:267–272, 2004
Testicular sonography: Is an echogenic ring a sign of a benign lesion?
Authors: Butteriss David J.A. , Elliott Simon T.
Published: June 2004

The differentiation of benign from malignant testicular lesions is important to avoid unnecessary surgical intervention but is often difficult, particularly in the case of focal hypoechoic lesions. We present the description of 3 cases of an echogenic ring that appeared around a hypoechoic testicular mass on sonograms. The ring proved to be a fibrous capsule around a benign lesion. If these observations are confirmed in larger series, the sonographic pattern described here may help reduce the number of orchiectomies performed for benign lesions. © 2004 Wiley Periodicals, Inc. J Clin Ultrasound 32:306–308, 2004
Hominins do not share a common postnatal facial ontogenetic shape trajectory
Authors: Cobb S.N. , O'Higgins P.
Published: June 2004

This paper examines the hypothesis raised by recent studies that postnatal trajectories of shape change in the facial skeleton are parallel between, at least, chimpanzees, modern humans and also fossil hominins, specifically australopithecines and possibly Neanderthals. In contrast, other studies point to divergences in postnatal shape trajectories within diverse groups of primates. As such there is some debate regarding the relative contributions of pre and postnatal ontogeny to adult morphological differences. This paper presents a series of geometric morphometric studies of the ontogeny of facial shape in hominins with the specific aim of resolving these issues. The results indicate that many differences in facial shape between hominins are established prenatally, however highly significant divergences of postnatal facial ontogeny are found among living hominins. Our studies point to possible differences between the shape ontogeny of theAustralopithecus africanusface and that of African apes on the one hand and humans on the other. However, sampling experiments indicate that the small sample size of available specimens ofA. africanusdoes not permit any conclusions to be drawn regarding comparative shape ontogeny of the face.J. Exp. Zool. (Mol. Dev. Evol.) 302B:302–321, 2004.© 2004 Wiley‐Liss, Inc.
Pressor effects of electrical stimulation of medial prefrontal cortex in unanesthetized rats
Authors: Tavares Rodrigo Fiacadori , Antunes‐Rodrigues José , de Aguiar Corrêa Fernando Morgan
Published: June 2004

The medial prefrontal cortex (MPFC) is involved in central nervous system (CNS)‐mediated cardiovascular modulation. We compared the cardiovascular effects of electrical stimulation (EE) of the MPFC in unanesthetized rats to those observed after stimulation of the same area in urethane‐anesthetized rats. Electrical stimulation (35, 106, 177, 247, 318, and 389 μA rms/10 sec, 60‐Hz sine wave) of the MPFC of urethane‐anesthetized rats caused depressor responses of stimulus‐related intensity. The cardiovascular response to electrical stimulation of the MPFC in unanesthetized rats was characterized by stimulus‐related pressor responses. No significant heart rate changes were observed during the EE period in any case. The pressor response to electrical stimulation (106 μA rms/10 sec, 60‐Hz sine wave) of the MPFC was not affected by intravenous pretreatment with the vasopressin antagonist dTyr(CH2)5(Me)AVP (50 μg/kg, intravenously), by hypophysectomy, or by intravenous pretreatment with the angiotensin II antagonist losartan (1 mg/kg, intravenously). The pressor response was blocked by intravenous pretreatment with the ganglionic blocker mecamylamine (2 mg/kg, intravenously) but was not affected by adrenal demedullation, thus suggesting involvement of the neural component of the sympathetic nervous system without a major involvement of its hormonal component. Our results confirmed the occurrence of depressor responses after electrical stimulation of the MPFC in urethane‐anesthetized rats and evidenced that only pressor responses are observed after its stimulation in unanesthetized rats. The fact that the pressor response to the stimulation of the MPFC was blocked by a ganglioplegic suggests that the MPFC has functional excitatory actions over the sympathetic nervous system. © 2004 Wiley‐Liss, Inc.
Treatment of cerebellar granule cell neurons with the neurotrophic factor pigment epithelium‐derived factor in vitro enhances expression of other neurotrophic factors as well as cytokines and chemokines
Authors: Yabe Takeshi , Herbert J. Taylor , Takanohashi Asako , Schwartz Joan P.
Published: June 2004

Microarray analyses demonstrated that a variety of genes was affected by treatment of cerebellar granule cell neurons with the neurotrophic factor pigment epithelium‐derived factor (PEDF). The genes for neurotrophins, glial cell‐derived neurotrophic factor (GDNF), and their receptors were regulated differentially in immature versus mature neurons; however, nerve growth factor (NGF), neurotrophin (NT)‐3, and GDNF did not contribute to the protective effect of PEDF. Brain‐derived neurotrophic factor (BDNF) seemed capable of inducing apoptosis, because a blocking antibody enhanced the protective effect of PEDF. In addition, PEDF exposure also stimulated expression of several cytokine and chemokine genes. Removal of the less than 1% of microglia in the cultures by treatment with L‐leucine methyl ester, combined with enzyme‐linked immunosorbent assays (ELISAs), demonstrated that the cerebellar granule cells constitutively produce three chemokines, macrophage inflammatory protein (MIP)‐1α, MIP‐2, and MIP‐3α, whose production is enhanced further by treatment with PEDF. Blocking antibodies to each of the chemokines was protective under control conditions, suggesting that they may contribute to the “natural” apoptosis occurring in the cultures, and enhanced the effects of PEDF. Although PEDF enhanced production of all three chemokines, the blocking antibodies did not increase its protective effect against induced apoptosis. These results suggest that although PEDF enhances expression of other neurotrophic factors or chemokines, it does not exert its neuroprotective effect on cerebellar granule cells through their production. © 2004 Wiley‐Liss, Inc.
Luminescence chronology of non‐glacial sediments in Changeable Lake, Russian High Arctic, and implications for limited Eurasian ice‐sheet extent during the LGM
Authors: Berger Glenn W. , Melles Martin , Banerjee Debabrata , Murray Andrew S. , Raab Alexandra
Published: June 2004

A 10.5 m core from Changeable Lake in the Severnaya Zemlya Archipelago just north of the Taymyr Peninsula intersects ca. 30 cm of diamicton at its base, interpreted as a basal till. Because the upper 10.13 m of this core consists of non‐glacial sediments, a maximum numeric age for these non‐glacial sediments would provide a clear lower limit to the timing of the last glaciation in the area of Changeable Lake. Radiocarbon (14C) dating of several materials from this core yielded widely scattered results. Consequently we applied photonic dating to sediments above the diamicton. The experimental single‐aliquot‐regenerative (SAR) dose fine‐grain method was applied to two samples, using the ‘double SAR’ approach. With one exception, these fine‐grain SAR results and the results of application of the SAR method to sand‐sized quartz grains from two samples, at ca. 9.95 m and ca. 10.05 m depth, are discrepant with age estimates from the multi‐aliquot infrared‐photon‐stimulated luminescence (IR‐PSL) method applied to fine grains. Multi‐aliquot IR‐PSL dating of 10 samples produces ages increasing monotonically from ca. 4 ka at 2 m to 53 ± 4 ka at 9.97 m. These self‐consistent multi‐aliquot IR‐PSL ages, along with limiting 14C ages of >47 ka at ca. 10 m, provide direct evidence that glacial ice did not advance over this lake basin during the Last Glacial Maximum, and thus delimit the northeastern margin of the Barents–Kara Sea ice‐sheet to somewhere west of this archipelago. The last regional glaciation probably occurred during marine isotope stage (MIS) 4 or earlier. Copyright © 2004 John Wiley & Sons, Ltd.
Pedosedimentary development of part of a Late Quaternary loess‐palaeosol sequence in northwest Argentina
Authors: Kemp Rob A. , King Matthew , Toms Philip , Derbyshire Edward , Sayago José Manuel , Collantes Miriam M.
Published: June 2004

The field properties, magnetic susceptibility, particle size, calcium carbonate content, soil micromorphology and optical luminescence ages of the upper 6.1 m and lowermost 4.7 m of the 45 m loess–palaeosol sequence at El Lambedero in the Tafí del Valle region of Tucumán Province (Sierras Pampeanas, northwest Argentina) have been used to set up a partial stratigraphy and chronology, as well as a basic pedosedimentary model of loess accumulation, palaeosol development, reworking and erosion for the site. The minimum ages derived from the basal part of the section suggest that loess began to accumulate some time before 165 ka. A thick and well‐developed pedocomplex in the upper profile is correlated with at least the latter part of marine isotope stage (MIS) 5, whereas the overlying palaeosol may be attributable to pedogenic activity during MIS 3. The absence of material younger than 33 ka close to the surface of this rounded spur landform is probably the result of either non‐deposition or erosional stripping in response to climatic change, or episodic uplift in this seismically active region. Copyright © 2004 John Wiley & Sons, Ltd.
Characterization of minerals and biogeochemical markers on Mars: A Raman and IR spectroscopic study of montmorillonite
Authors: Bishop Janice L. , Murad Enver
Published: June 2004

Raman spectroscopy is likely to be one of a number of instruments deployed to Mars on future landed missions. The goals of these missions will include characterizing the mineralogy of the rocks and soils, in addition to determining if the planet may be or may have been habitable for life. The astrobiology questions are linked to understanding the aqueous and biogeochemical history of Mars. Clay minerals are studied here because if they are found on Mars they may provide information about the geochemistry of the primary rocks and the aqueous history of the planet. This study compares Raman and IR spectra of the SWy‐1, STx‐1 and SAz‐1 montmorillonites. These samples contain admixtures of organic material, carbonate, amorphous silica and fine‐grained quartz, which can all be detected using Raman spectroscopy. Less than 0.1 wt% C as organic material was detected in each of the samples through peaks associated with CC or CH bonds. Carbonate was detected in the Raman spectra for the sample containing 1.65 wt% CO3 but not for 0.15 wt% CO3. Raman spectra exhibit unique bands near 200 and 700 cm−1 that are due to tetrahedral SiO4 in layer silicates and vary depending on the mineral structure. Raman spectra of clay minerals also have unique metal–OH bending vibrations between 840 and 920 cm−1 that provide information about the octahedral cations present. Copyright © 2004 John Wiley & Sons, Ltd.
Morphological, thermal, rheological and retrogradation properties of potato starch fractions varying in granule size
Authors: Singh Narpinder , Kaur Lovedeep
Published: June 2004

The physicochemical properties of small, medium and large starch granules separated from four potato cultivars were investigated to reveal whether functional properties differed among the various size classes of the starches. Large‐size fractions showed higher amylose content and light transmittance and lower swelling power than small‐size fractions. The granules from the three fractions had diameters of 5–20, 25–40 and 40–85 µm respectively. The large and medium granules were ellipsoidal to irregular or cuboidal while the small granules were spherical or ellipsoidal in shape. The transition temperatures and gelatinisation temperature range of the fractionated starches increased while the enthalpy of gelatinisation decreased with decreasing granule size. Rheological parameters such as peak storage (G′) and loss (G″) moduli increased in the order small‐, medium‐ and large‐granule starches when subjected to temperature sweep testing. The breakdown in peak G′ during the heating cycle and retrogradation during storage were found to be highest for large‐ and lowest for small‐size fractions. The differences in functional properties among the different size fractions suggested that the granule size distribution is an important parameter that can influence the behaviour of potato starch during processing. Copyright © 2004 Society of Chemical Industry
Lipid oxidation and colour in pressure‐ and heat‐treated minced chicken thighs
Authors: Beltran Elena , Pla Reyes , Capellas Marta , Yuste Josep , Mor‐Mur Montserrat
Published: June 2004

Lipid oxidation and colour in pressurised and heated chicken samples were evaluated. In a preliminary test, raw and overcooked (100 °C/60 min) minced chicken thighs were pressurised (500 MPa/50 °C/30 min). Samples were stored at 4 °C in contact with air. Thiobarbituric acid reactive substances (TBARS) were quantified at 1, 6 and 9 days. Pressure induced oxidation in chicken, but overcooking generated many more secondary oxidation compounds. In a second experiment, raw minced chicken thighs were pressurised (500 MPa/−10, 5, 20 and 50 °C/30 and 60 min) or cooked (90 °C/15 min). Samples were vacuum stored at 4 °C. TBARS were measured at 1 and 9 days, whereas colour parameters (L, a, b and ΔE) were determined at 1 day. No differences in TBARS values were observed between untreated and pressurised samples, whereas cooked samples presented the highest values. Pressurisation for 30 and 60 min generated similar TBARS contents. At 9 days, oxidation values did not increase. Pressurisation and cooking induced marked colour changes. Pressurised samples were lighter and less red than untreated ones. Samples pressurised at 50 °C were the palest and, together with cooked samples, presented the lowest a values. Therefore pressurised chicken thigh cannot be marketed as a fresh product but can be incorporated as an ingredient in ready‐to‐eat meals. Copyright © 2004 Society of Chemical Industry
Cover Picture: Macromol. Chem. Phys. 9/2004
Authors: Tohi Yasushi , Nakano Takashi , Makio Haruyuki , Matsui Shigekazu , Fujita Terunori , Yamaguchi Tsutomu
Published: June 2004

Cover: The cover shows the unique polymerization behavior of FI Catalysts, which is the production of well‐defined uni‐ and bimodal polyethylenes. This polymerization behavior stems from the fact that FI Catalysts can possess more than one catalytically active species arising from the coordination modes of two non‐symmetric ligands. The FI catalysis represents a notable example of the formation of bimodal polymers by a single precatalyst in a single‐stage polymerization process.

Further details can be found in the Full Paper by Y. Tohi, T. Nakano, H. Makio, S. Matsui, T. Fujita* and T. Yamaguchi on page 1179.
Thermal Stability of Gamma Irradiated Low Density Polyethylene Films Containing Hindered Amine Stabilizers
Authors: Zaharescu Traian , Kaci Mustapha , Hebal Ghania , Setnescu Radu , Setnescu Tanta , Khima Rochedine , Remili Chérifa , Jipa Silviu
Published: June 2004

Summary: The thermal stability of gamma irradiated low density polyethylene (LDPE) films in presence of various structures of hindered amine stabilizers (HAS) was investigated by the oxygen uptake method under constant temperature of 180 °C and normal pressure conditions. The thermo‐oxidation was run using air environment. The sigmoidal dependency of oxygen uptake allows the calculation of the main kinetic parameters: oxidation induction time and oxidation rate on the propagation step. The various steps involved in the thermal degradation process were detected by the derivative procedure applied to the dependencies of oxygen uptake on time. It was found that the kinetic parameters of the thermal degradation process, determined by oxygen uptake, revealed the antioxidant role of HAS in γ‐irradiated LDPE films by providing better stability, when compared with the unstabilized samples. Moreover, the results indicated that the dependencies of oxygen uptake on thermal degradation time involved two degradation stages: the former occurring in the ungrafted moiety and the latter taking place after the antioxidant depletion is achieved. The stabilization efficiency of these oxidation inhibitors provides satisfactory thermal resistance to LDPE films, especially those based on an alkoxyamine structure.

Dependencies of oxygen uptake on time at the thermal degradation of LDPE irradiated at 812 kGy. (‐□‐) free of additive; (‐○‐) Tinuvin 123; (‐▵‐) Sanduvor PR 31; (‐⋄‐) Uvasil 299.

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Dependencies of oxygen uptake on time at the thermal degradation of LDPE irradiated at 812 kGy. (‐□‐) free of additive; (‐○‐) Tinuvin 123; (‐▵‐) Sanduvor PR 31; (‐⋄‐) Uvasil 299.
Reactive Compatibilizer Precursors for LDPE/PA6 Blends, 4
Authors: Filippi Sara , Yordanov Hristo , Minkova Liliya , Polacco Giovanni , Talarico Marco
Published: June 2004

Summary: The effectiveness of some thermoplastic elastomers grafted with maleic anhydride (MA) or with glycidyl methacrylate (GMA) as compatibilizer precursors (CPs) for blends of low density polyethylene (LDPE) with polyamide‐6 (PA) has been studied. The CPs were produced by grafting different amounts of MA or GMA onto a styrene‐block‐(ethylene‐co‐1‐butene)‐block‐styrene copolymer (SEBS) (KRATON G 1652), either in the melt or in solution. A commercially available SEBS‐g‐MA copolymer with 1.7 wt.‐% MA (KRATON FG 1901X) was also used. The effect of the MA concentration and of other characteristics of the SEBS‐g‐MA CPs was also studied. The specific interactions between the CPs and the blends components were investigated through characterizations of the binary LDPE/CP and PA/CP blends, in the whole composition range. It was demonstrated that the SEBS‐g‐GMA copolymers display poor compatibilizing effectiveness due to cross‐linking resulting from reactions of the epoxy rings of these CPs with both the amine and the carboxyl end groups of PA. On the contrary, the compatibilizing efficiency of the MA‐grafted elastomers, as revealed by the thermal properties and the morphology of the compatibilized blends, was shown to be excellent. The results of this study confirm that the anhydride functional groups possess considerably higher efficiency, for the reactive compatibilization of LDPE/PA blends, than those of the ethylene‐acrylic acid and ethylene‐glycidyl methacrylate copolymers investigated in previous works.

SEM micrograph of the 75/25 LD08/PA blend (with 2 phr SEBSMA1).

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SEM micrograph of the 75/25 LD08/PA blend (with 2 phr SEBSMA1).
Elaboration of Poly(ε‐caprolactone)‐g‐TiNbO5 Nanocomposites via in situ Metal Complex Initiated Intercalative Polymerization
Authors: Bruzaud Stéphane , Carpentier Jean‐François , Grohens Yves
Published: June 2004

Summary: The preparation of poly(ε‐caprolactone)‐g‐TiNbO5 nanocomposites via in situ intercalative polymerization of ε‐caprolactone initiated by an aluminium complex is described. These nanocomposites were obtained in the presence of HTiNbO5 mineral pre‐treated by AlMe3, but non‐modified by tetraalkylammonium cations. These hybrid materials obtained have been characterized by Fourier transform infrared absorption spectroscopy, wide‐angle X‐ray scattering, scanning electron microscopy, and dynamic mechanical analysis. Layered structure delamination and homogeneous distribution of mineral lamellae in the poly(ε‐caprolactone) (PCL) is figured out and strong improvement of the mechanical properties achieved. The storage modulus of the nanocomposites is enhanced as compared to pure PCL and increases monotonously with the amount of the filler in the range 3 to 10 wt.‐%.

SEM image of the fractured surface of a PCL‐TiNbO5 nanocomposite film.

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SEM image of the fractured surface of a PCL‐TiNbO5 nanocomposite film.
Structural and Mechanical Properties Changes of Ethylene‐α‐olefin Copolymer Blends Induced by Thermal Treatments and Composition
Authors: Chen Fei , Shanks Robert A. , Amarasinghe Gandara
Published: June 2004

Summary:Blends of single‐site catalysed ethylene‐α‐butene (C4VLDPE) and ethylene‐α‐octene (C8VLDPE) copolymers were prepared by melt extrusion. The phase morphology, thermal and mechanical properties of the blends have been investigated by differential scanning calorimetry (DSC), scanning electron microscopy (SEM), tensile test and dynamic mechanical analysis (DMA). Depending on the composition and thermal history, significant differences in structure and behaviour were found. It was also found that some degree of co‐crystallization occurred for quenched blends; whereas most of the oven slowly cooled blends showed two well‐defined melting peaks, indicating that the slow cooling favoured partial segregation of the fractions with different degrees of branching to form two morphologies. Moreover, SEM revealed morphology of the thinner crystals distributed in‐between the thicker sheaf‐like crystals for the slowly cooled blends with 20–50% C8VLDPE. Therefore, the synergism in mechanical properties for the blends with 20–50% C8VLDPE is due to a combination of larger crystal size, more complete phase separation and interfacial interaction produced by the segregation effect of the slow cooling treatment. DMA studies showed that the storage modulus increased as the addition of C8VLDPE and modulus for the slowly cooled blends are about twice those measured for the quenched ones, indicating higher stiffness of the blends. The smooth shift ofβrelaxation temperature with addition of C8VLDPE for both sets of blends confirmed the miscibility in the amorphous phase.

SEM image of the C4VLDPE‐C8VLDPE (50/50) blend after oven slow cooling treatment.

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SEM image of the C4VLDPE‐C8VLDPE (50/50) blend after oven slow cooling treatment.
Methionine‐Containing Poly(amino acid) Hybrid Fibers via Self‐Assembly at Aqueous Interface
Authors: Satoyoshi Daijiro , Hachisu Masakazu , Amaike Masato , Ohkawa Kousaku , Yamamoto Hiroyuki
Published: June 2004

Summary: Using sulfonium groups to create a novel fiber material, methionine‐containing hybrid fibers were prepared from S‐methylated poly(L‐methionine) and poly(L‐lysine, L‐methionine) solutions with gellan solution by polyion complex (PIC) formation via self‐assembly at the aqueous interface. The breaking strain of the PIC fibers were increased by incorporation of methionine residues into the poly(L‐lysine). These findings may provide a new approach for preparing a wool‐like fiber in aqueous media using the synthetic water‐soluble methionine‐containing poly(amino acid)s.

SEM image of Met‐containing PIC fiber: (a) poly[Met19Met(SMe)81]‐gellan fiber (magnification, ×500).

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SEM image of Met‐containing PIC fiber: (a) poly[Met19Met(SMe)81]‐gellan fiber (magnification, ×500).
Recent Advances for Intumescent Polymers
Authors: Bourbigot Serge , Le Bras Michel , Duquesne Sophie , Rochery Maryline
Published: June 2004

Summary: This paper reviews recent approaches for making intumescent systems. The mechanisms of action involving intumescence are described and commented on. Synergistic aspects using zeolites and organoclays are also considered and discussed. New strategies are examined on the basis of the mechanism of intumescence. The approach of using char forming polymers as additives (blend technology) is also fully discussed. This consists of substituting classical polyols (char forming agents) with char forming polymers (polyamides and thermoplastic polyurethane). It will be shown that the advantages of this concept are to obtain flame‐retarded (FR) polymer blends with improved mechanical properties in comparison with polymers loaded with classical formulations, and the avoidance of problems due to the water solubility of the polyols and their migration. The “nanocomposite approach” enhances the performance of intumescent systems by using a nanostructured char forming polymer. It will be shown that this combination of intumescence via the blending approach and nanocomposites enhances both flame retardancy and mechanical properties, and allows many specifications to be produced (for example, the design of EVA‐based materials for flame retarded low voltage cables and wire). This appears to be one of the most promising ways for designing new efficient intumescent materials.

Intumescent residue after LOI test of an intumescent poly(propylene).

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Intumescent residue after LOI test of an intumescent poly(propylene).
Effects of Temperature and Surfactants on the Equilibrium Swelling Behavior of Poly[acrylamide‐co‐(itaconic acid)] Hydrogels
Authors: Çaykara Tuncer , Doğmuş Melike
Published: June 2004

Summary: The swelling equilibrium of poly(acrylamide) [PAAm] and poly[acrylamide‐co‐(itaconic acid)] [P(AAm/IA)] hydrogels was studied as a function of temperature and IA content in aqueous solutions of surfactants: sodium dodecyl sulfate (SDS, anionic) and hexadecyltrimethylammonium bromide (HTAB, cationic). P(AAm/IA) hydrogels in water exhibited reentrant conformational transitions depending on temperature, whereas PAAm hydrogels were not affected with the change of temperature. The equilibrium‐volume‐swelling ratio of P(AAm/IA) hydrogels increased sharply in SDS solutions, with an increase of the mole percent of IA. However, in HTAB solution, the equilibrium‐volume‐swelling ratio of these hydrogels decreased with an increase of IA content.

The equilibrium volume‐swelling ratios of the hydrogels in water shown as a function of temperature.

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The equilibrium volume‐swelling ratios of the hydrogels in water shown as a function of temperature.
Novel Hyperbranched Poly([1,2,3]‐triazole)s Derived from AB2 Monomers by a 1,3‐Dipolar Cycloaddition
Authors: Scheel Arnulf J. , Komber Hartmut , Voit Brigitte I.
Published: June 2004

Summary: Novel hyperbranched poly([1,2,3]‐triazole)s were synthesized from several AB2 monomers by a 1,3‐dipolar cycloaddition reaction. The compound 3,5‐bis(propargyloxy)benzyl azide was polymerized thermally at room temperature leading to 1,4‐ and 1,5‐disubstituted poly([1,2,3]‐triazole) and catalytically leading only to the 1,4‐disubstituted poly([1,2,3]‐triazole). Only the thermal reaction led to fully soluble products. The AB2 monomers containing an internal alkyne A unit could be autopolymerized thermally under mild reaction conditions leading to soluble, high‐molecular‐weight hyperbranched poly([1,2,3] triazole)s. All products were characterized by detailed NMR investigations.

Synthesis route for polymers 8a and 8b.

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Synthesis route for polymers 8a and 8b.
Self‐Assembly of Poly(γ‐benzyl L‐glutamate)‐graft‐Poly(ethylene glycol) and Its Mixtures with Poly(γ‐benzyl L‐glutamate) Homopolymer
Authors: Tang Dongmei , Lin Jiaping , Lin Shaoliang , Zhang Suning , Chen Tao , Tian Xiaohui
Published: June 2004

Summary: Self‐association behaviors of poly(γ‐benzyl L‐glutamate)‐graft‐poly(ethylene glycol) (PBLG‐graft‐PEG) and its mixtures with PBLG homopolymer in aqueous media were investigated by fluorescence spectroscopy, transmission electron microscopy (TEM), and nuclear magnetic resonance (NMR) spectroscopy. It was revealed that PBLG‐graft‐PEG could self‐assemble to form polymeric micelles with a core‐shell structure in the shape of spindle. The introduction of PBLG homopolymer not only decreases the critical micelle concentration, but also changes the morphology of the micelles.

The excitation fluorescence spectra of pyrene as a function of concentrations for the mixture of PBLG‐graft‐PEG with PBLG and a TEM image of the formed micelles.

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The excitation fluorescence spectra of pyrene as a function of concentrations for the mixture of PBLG‐graft‐PEG with PBLG and a TEM image of the formed micelles.
Polysilane‐Cycloimmonium Salts: New Materials for Organic Semiconductors
Authors: Ardeleanu Rodinel , Mangalagiu Ionel , Sacarescu Gabriela , Simionescu Mihaela , Sacarescu Liviu
Published: June 2004

Summary: This work presents the first synthesis of a new polymer obtained by catalytic addition of the SiH groups of a poly[methyl(H)silane‐co‐methylphenylsilane] backbone to an N‐(allyl)cycloimmonium salt. This hybrid polymer was characterized by spectroscopic analysis, thermogravimetric analysis and gel‐permeation chromatography (GPC). The pendant N‐(allyl)cycloimmonium segments lead to the formation of molecular dipoles, as evidenced by electrical polarization experiments.

Structure of the polysilane‐cycloimmonium salt.

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Structure of the polysilane‐cycloimmonium salt.
End‐Group Characterization of Poly(acrylic acid) Prepared by Nitroxide‐Mediated Controlled Free‐Radical Polymerization
Authors: Lefay Catherine , Belleney Joël , Charleux Bernadette , Guerret Olivier , Magnet Stéphanie
Published: June 2004

Summary: A low‐molar‐mass poly(acrylic acid) with a narrow molar‐mass distribution, prepared by SG1 nitroxide‐mediated controlled free‐radical polymerization, was subjected to end‐group analysis to confirm its living nature. 1H and 31P NMR spectroscopy confirmed the presence of the SG1‐based alkoxyamine end group. Furthermore, chain extension with styrene and n‐butyl acrylate demonstrated the ability of the homopolymer to initiate the polymerization of a second block. These results open the door to the synthesis of poly(acrylic acid)‐based block copolymers by direct nitroxide‐mediated polymerization of acrylic acid.

Acrylic acid polymerization using an alkoxyamine initiator based on SG1 (N‐tert‐butyl‐N‐(1‐diethyl phosphono‐2,2‐dimethylpropyl) nitroxide resulting in a homopolymer capable of initiating the polymerization of a second block.

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Acrylic acid polymerization using an alkoxyamine initiator based on SG1 (N‐tert‐butyl‐N‐(1‐diethyl phosphono‐2,2‐dimethylpropyl) nitroxide resulting in a homopolymer capable of initiating the polymerization of a second block.
Partially Sulfonated Polystyrene and Poly(2,6‐dimethyl‐1,4‐phenylene oxide) Blend Membranes for Fuel Cells
Authors: Kim Bokyung , Jung Bumsuk
Published: June 2004

Summary: Based on Flory–Huggins parameters (χ), the miscibility and the effect of morphological change on proton conductivity and methanol permeability of partially sulfonated polystyrene (SPS) and partially sulfonated poly(2,6‐dimethyl‐1,4‐phenylene oxide) (SPPO), having an identical ion exchange capacity, were investigated. When 50 wt.‐% of SPPO was blended, both the proton conductivity and methanol permeability had the highest values, which resulted from the change of amorphous domains and the hydrogen bonding between the two ionomers.

The proton conductivities, water uptake and methanol permeability for the SPPO/SPS blend membranes studied here. The membranes with 50 wt.‐% SPPO clearly showed the greatest increase in these properties.

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The proton conductivities, water uptake and methanol permeability for the SPPO/SPS blend membranes studied here. The membranes with 50 wt.‐% SPPO clearly showed the greatest increase in these properties.
Monomode Microwave‐Assisted Atom Transfer Radical Polymerization
Authors: Zhang Huiqi , Schubert Ulrich S.
Published: June 2004

Summary: The first monomode microwave‐assisted atom transfer radical polymerization (ATRP) is reported. The ATRP of methyl methacrylate was successfully performed with microwave heating, which was well controlled and provided almost the same results as experiments with conventional heating, demonstrating the absence of any “microwave effect” in ATRP (in contrast to several literature reports). Furthermore, we found that the main advantage of the microwave‐assisted reactions over conventional reactions, i.e., a significant increase of reaction rates, only had its limited application in ATRP, even in very slow ATRP systems with high targeted molecular weights.

Comparison of the kinetic plots of the ATRP of MMA ([MMA]0/[EBIB]0/[CuCl]0/[NHPMI]0 = 200:1:1:3, MMA/DMF = 1:1 v/v) carried out at 90 °C in DMF with microwave (▴) and conventional heating (•), respectively.

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Comparison of the kinetic plots of the ATRP of MMA ([MMA]0/[EBIB]0/[CuCl]0/[NHPMI]0 = 200:1:1:3, MMA/DMF = 1:1 v/v) carried out at 90 °C in DMF with microwave (▴) and conventional heating (•), respectively.
Novel Approach to Fabricate Carbon Molecular‐Sieve Membranes Based on Consideration of Interpenetrating Networks
Authors: Tin Pei Shi , Chung Tai‐Shung
Published: June 2004

Summary: Carbon molecular‐sieve membranes (CMSMs) have shown great potential for gas separation. They exhibit high selectivity by permitting effective size‐ and shape‐separation between gas molecules of similar molecular dimensions. Hence, the control of their pore size is very important. While previous studies have focused on the conditions of pyrolysis and its effect on CMSM properties, a novel approach is reported here whereby the precursor polymer is chemically modified prior to pyrolysis and the resultant CMSM was investigated for its gas separation properties. Pyrolysis of chemically crosslinked and uncrosslinked Matrimid® resulted in a change in d‐spacing from 5.6 to 3.6 and 3.7 Å, respectively. The crosslinked CMSM also exhibited greater ordering in its packing. The Matrimid‐derived CMSMs exhibited excellent separation properties for CO2/CH4.

Mechanism of chemical crosslinking modification.

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Mechanism of chemical crosslinking modification.
Cover Picture: Macromol. Rapid Commun. 12/2004
Authors: Michishita Takeshi , Takashima Yoshinori , Harada Akira
Published: June 2004

Cover: Polyisoprenes were found to form inclusion complexes with cyclodextrins with high selectivity to give crystalline compounds. β‐Cyclodextrin formed complexes only with polyisoprene of low molecular weight. γ‐Cyclodextrin formed complexes with polyisoprenes of high molecular weight. α‐Cyclodextrin did not form complexes with polyisoprene of any molecular weight.

Further details can be found in the Communication by T. Michishita, Y. Takashima, and A. Harada* on page 1159.
Consumer rationality and credit card pricing: An explanation based on the option value of credit lines
Authors: Park Sangkyun
Published: June 2004

An option is embedded in credit cards. Since credit cards offer open credit lines, cardholders can borrow at the same terms when they become riskier. This option value raises the zero‐profit card rate. Furthermore, adverse selection occurs if cardholders are better informed about the probability of becoming riskier in the future and borrow more when they become riskier. The adverse selection can limit rate competition and keep the card rate above the zero‐profit card rate. An up‐front fee is not a good alternative because it is also vulnerable to adverse selection. A low introductory card rate is an effective way to avoid the adverse selection problem when asymmetric information is mainly about the change in the borrower's risk profile in the future, as opposed to the riskiness in the present period. Copyright © 2004 John Wiley & Sons, Ltd.
Residual income claimancy, monitoring, and the R&D firm: Theory with application to biotechs
Authors: Chang Koyin , Garen John
Published: June 2004

This paper models the assignment of residual income claimancy to an R&D manager and applies the model to biotechnology firms. Residual income claimancy provides incentives for the manager to monitor the R&D process. Since the nature of R&D and of monitoring scientific effort is different, our model predicts stark differences in the residual income claimancy of managers and in other aspects of organization for innovative R&D firms like biotechs. In particular, R&D firms are expected to be more owner‐managed, more expert‐managed, and smaller in size. Cross‐sectional data on biotechnology firms is consistent with these implications. Additionally, longitudinal data indicate that as firms alter their focus on biotech research, their organizational structure changes as expected. Our approach suggests a process of firm and industry evolution related to technological maturity and points to the importance of incentives rather than risk sharing in determining organizational form, similar to the original analysis of franchising. Copyright © 2004 John Wiley & Sons, Ltd.
Movement Disorder Society Task Force report on the Hoehn and Yahr staging scale: Status and recommendations The Movement Disorder Society Task Force on rating scales for Parkinson's disease
Authors: Goetz Christopher G. , Poewe Werner , Rascol Olivier , Sampaio Cristina , Stebbins Glenn T. , Counsell Carl , Giladi Nir , Holloway Robert G. , Moore Charity G. , Wenning Gregor K. , Yahr Melvin D. , Seidl Lisa
Published: June 2004

The Movement Disorder Society Task Force for Rating Scales for Parkinson's disease (PD) prepared a critique of the Hoehn and Yahr scale (HY). Strengths of the HY scale include its wide utilization and acceptance. Progressively higher stages correlate with neuroimaging studies of dopaminergic loss, and high correlations exist between the HY scale and some standardized scales of motor impairment, disability, and quality of life. Weaknesses include the scale's mixing of impairment and disability and its non‐linearity. Because the HY scale is weighted heavily toward postural instability as the primary index of disease severity, it does not capture completely impairments or disability from other motor features of PD and gives no information on nonmotor problems. Direct clinimetric testing of the HY scale has been very limited, but the scale fulfills at least some criteria for reliability and validity, especially for the midranges of the scale (Stages 2–4). Although a “modified HY scale” that includes 0.5 increments has been adopted widely, no clinimetric data are available on this adaptation. The Task Force recommends that: (1) the HY scale be used in its original form for demographic presentation of patient groups; (2) when the HY scale is used for group description, medians and ranges should be reported and analysis of changes should use nonparametric methods; (3) in research settings, the HY scale is useful primarily for defining inclusion/exclusion criteria; (4) to retain simplicity, clinicians should “rate what you see” and therefore incorporate comorbidities when assigning a HY stage; and (5) because of the wide usage of the modified HY scale with 0.5 increments, this adaptation warrants clinimetric testing. Without such testing, however, the original five‐point scales should be maintained. © 2004 Movement Disorder Society
Risk and incidence of dementia in a cohort of older subjects with Parkinson's disease in the United Kingdom
Authors: Hobson Peter , Meara Jolyon
Published: June 2004

To determine the incidence and possible risk factors for dementia in patients with clinically probable Parkinson's disease (PD), a cohort (n = 86) of nondemented patients over 65 years of age with PD fulfilling the PD Brain Bank clinical diagnostic criteria were determined from community records. A similarly aged group of control subjects (n = 102) were recruited from the same area. Both groups were assessed at baseline and approximately 4 years later for cognition, mood, and motor function (PD patients only). The presence and severity of cognitive impairments was based on subject and informant interview, neuropsychological assessment based on the Cambridge Cognitive Examination (CAMCOG) and the application of the Diagnostic and Statistical Manual of Mental Disorders, 4th edition (DSM‐IV). At 4 years, 51 (59%) of the PD and 72 (71%) of the control cohort were available for reassessment. Of the PD cohort, 18 (35.3%) had developed dementia and 5 (9.4%) had evidence of mild cognitive impairments. In the control group, 5 (7%) had developed dementia. The incidence of dementia per 1,000 person‐years in the PD cohort was 107.1 (95% confidence interval [CI], 59.9–159.8) and in the control group was 17.9 (95% CI, 5.8–31.9). The relative risk of patients developing dementia was 5.1 times that of the controls (95% CI, 2.1–12.5). Increasing age, later age of onset of PD, longer duration of PD symptoms, the presence of hallucinations, and impairment of memory and language function were all predictive factors for the development of dementia (P < 0.05). Dementia was also found to be a significant predictor for institutional placement in the PD group. Compared with similarly aged controls, patients with clinically probable PD have a fivefold‐increased risk of developing dementia. This finding has significant implications for successful clinical management of this condition. © 2004 Movement Disorder Society
Inherited myoclonus‐dystonia and epilepsy: Further evidence of an association?
Authors: O'Riordan Sean , Ozelius Laurie J. , De Carvalho Aguiar Patricia , Hutchinson Michael , King Mary , Lynch Tim
Published: June 2004

Epilepsy and electroencephalogram (EEG) abnormalities have been considered exclusion criteria for the clinical diagnosis of myoclonus‐dystonia (M‐D). We report on the second M‐D family in which several clinically affected ϵ‐sarcoglycan gene (SGCE) mutation carriers have seizures in addition to myoclonus and dystonia, adding to the evidence that epilepsy and EEG abnormalities may form part of the phenotypic spectrum of the condition. A nonsense mutation in exon 3 (289C→T) of SGCE resulting in the insertion of a premature stop codon (R97X) was detected in affected members of this family. © 2004 Movement Disorder Society
An autopsy case of chronic inflammatory demyelinating polyradiculoneuropathy with respiratory failure
Authors: Sasaki Miho , Ohara Shinji , Oide Takashi , Hayashida Kensuke , Hayashi Ryoichi
Published: June 2004

An 85‐year‐old Japanese woman presented with progressive symmetrical proximal and distal muscle weakness, numbness in the distal extremities, and sudden onset of hemifacial weakness. The results of laboratory studies fulfilled the American Academy of Neurology criteria for chronic inflammatory demyelinating polyradiculoneuropathy (CIDP). She died of respiratory failure after two courses of intravenous immunoglobulin treatment, each resulting in transient improvement in strength and sensory symptoms. Autopsy revealed multifocal demyelinative or axonal lesions of varying severity affecting the cranial and peripheral nerves and including the phrenic nerve. These findings suggest that the clinical phenotype of CIDP depend on distribution and severity of the anatomical lesions. Muscle Nerve 30:382–387, 2004
Galvanic vestibular stimulation alters the onset of motor unit discharge
Authors: Kennedy Paul M. , Cresswell Andrew G. , Chua Romeo , Inglis J. Timothy
Published: June 2004

We have previously shown that galvanic vestibular stimulation (GVS) can modulate the amplitude of the passive soleus H‐reflex. This study examined whether the response resulted from a general change in excitability of the motoneuron pool or a specific modulation of individual motor units (MUs). Subjects performed slow isometric plantarflexor actions in a prone lying and kneeling position until the discharge of a single gastrocnemius MU was detected. During randomly selected trials, a 1‐mA bipolar, binaural galvanic stimulus was triggered just prior to the start of plantarflexor activity. With the knee extended and the medial gastrocnemius (MG) at a long muscle length, GVS did not have an effect on MU activity. However, when the knee was flexed and the MG muscle was shortened, GVS significantly modified the onset of activation and the initial firing frequency of MUs. This may reflect a change in the gain of the presynaptic inhibitory mechanisms that act on the motoneuron pool once a muscle reaches a shortened, nonoptimal force‐producing length. Thus, GVS may provide an important research tool for activating descending vestibulospinal pathways that act on lower‐limb motoneurons and may be applied to test the integrity of the spinal cord. Muscle Nerve 188–194, 2004
Morvan's syndrome: Clinical, laboratory, and in vitro electrophysiological studies
Authors: Löscher Wolfgang N. , Wanschitz Julia , Reiners Karlheinz , Quasthoff Stefan
Published: June 2004

Morvan's syndrome is a rare disorder characterized by neuromyotonia, hyperhidrosis, and central nervous system dysfunction. We report a patient with features of this syndrome, but who initially presented with breathing difficulties. Concentric needle electromyography showed an abundance of myokymic and neuromyotonic discharges. Exercise tests and repetitive nerve stimulation showed a decrement–increment response of compound muscle action potentials. Antibodies against voltage‐gated potassium channels were not detected on repeated testing, but the presence of oligoclonal bands in the cerebrospinal fluid (CSF) suggested an autoimmune etiology. At follow‐up over 3 years, no cancer was found. Electrophysiological in vitro studies of effects of patient serum and CSF on rat nerves provided no evidence of altered voltage‐gated sodium or potassium conductances. We conclude that putative humoral factors do not block ion channels acutely but may cause channel dysfunction with chronic exposure. Muscle Nerve 30: 157–163, 2004