bluuebunny/crossref_metadata_2025_split huggingface dataset:
Fetal intracranial calcification: Pseudo‐TORCH phenotype and discussion of related phenotypes
Authors: Kulkarni Akhil Muralidhar , Baskar Shankar , Kulkarni Muralidhar Laxmanrao , Kulkarni Abhishek Jayateerth , Mahuli Amit Vasanth , Vittalrao Suhasini , Kulkarni Preethi Muralidar 
Published: March 2010

AbstractFetal intracranial calcification (ICC) noted during antenatal imaging poses a diagnostic challenge. Although this presentation is most commonly associated with intrauterine infection, non‐infectious causes of fetal ICC have been reported and include metabolic, genetic, or hemodynamic conditions. We report on a patient with antenatally detected extensive ICC, in whom postnatal imaging revealed a distinctive band‐like ICC with abnormal gyral pattern and a negative serology for TORCH infections. Such a constellation of findings have been previously described under the terminology of “pseudo‐TORCH phenotype,” and we posit that our patient represents this entity. Our patient had unreported dysmorphic features, which expands the phenotypic spectrum of this recently described heterogenous condition. In addition we report on the progression of the phenotype both clinically and radiologically. In view of the limited information available for the differential diagnosis of fetal ICC, we also review the available literature on this topic. © 2010 Wiley‐Liss, Inc.
Familial Aicardi–Goutières syndrome due to SAMHD1 mutations is associated with chronic arthropathy and contractures
Authors: Dale Russell C. , Gornall Hannah , Singh‐Grewal Davinder , Alcausin Melanie , Rice Gillian I. , Crow Yanick J. 
Published: March 2010

AbstractWe report on two siblings doubly heterozygous for null mutations in the recently identified AGS5 gene SAMHD1. The older female child showed mild intellectual disability with microcephaly. Her brother demonstrated a significant spastic paraparesis with normal intellect and head size. Both children had an unclassified chronic inflammatory skin condition with chilblains, and recurrent mouth ulcers. One child had a chronic progressive deforming arthropathy of the small and large joints, with secondary contractures. This family illustrate the remarkable phenotypic diversity accruing from mutations in genes associated with Aicardi–Goutières syndrome (AGS). The association of arthropathy with SAMHD1 mutations highlights a phenotypic overlap of AGS with familial autoinflammatory disorders such as chronic infantile neurological cutaneous and articular syndrome (CINCA). This family therefore illustrate the need to consider mutation analysis of SAMHD1 in non‐specific inflammatory phenotypes of childhood. We propose that arthropathy with progressive contractures should now be considered part of the spectrum of Aicardi–Goutières syndrome because of SAMHD1 mutations. © 2010 Wiley‐Liss, Inc.
New subtype of familial intracranial calcification in a mother and two children
Authors: Elsaid Mahmoud F. , Crow Yanick J. , Livingston John H. , Ben‐Omran Tawfeg 
Published: March 2010

AbstractWe report on a mother and two children from a consanguineous Arab Qatari family demonstrating a highly distinctive pattern of intracranial calcification involving the globus pallidus, posterior limb of the internal capsule, genu of the corpus callosum, and deep white matter. Both siblings, a girl and boy, presented with neonatal seizures without subsequent deterioration in neurological function. The girl demonstrated mild to moderate psychomotor delay but her brother and mother showed completely normal development. All three affected individuals were normocephalic. To the best of our knowledge this phenotype represents a novel disorder of inherited brain calcification, which may be recognizable on computerized tomography brain imaging in other cases. Although the disease shows apparent autosomal dominant inheritance, the high degree of consanguinity in the family leaves open the possibility of pseudo‐dominance for an autosomal recessive trait. © 2010 Wiley‐Liss, Inc.
Flocculation of reed pulp suspensions by quaternary chitosan‐nanoparticle SiO2retention aid systems
Authors: Zhang Xiaohui , Gu Wen Juan , Li Houbin , Chi Huang , Chen Lingyun 
Published: March 2010

AbstractThe microparticle retention aid system has been a focus on the studies of paper‐making chemicals.N‐(2‐Hydroxy‐3‐trimethylammonio)‐propyl chitosan chlorider [quaternary chitosan (QCS)]—nanoparticle SiO2dual component system was investigated in this work. The adsorpton kinetic experiments indicated that there was a very fast (<1 min) polymer adsorption under good mixing conditions. Adsorption of QCS onto the fiber surface was followed by a rearrangement to reach an equilibrium conformation. At the same time, QCS chains, existing on the surface of fiber, could permeate into the porous of the fiber, resulting in the reducing of zeta potential of the cellulosic fiber. In addition, the flocculation would be increased with the increasing of SiO2when the fiber substrates surfaces was net positively charged by an adsorbed QCS layer. It was also found that ionic strength decreased significantly the flocculation efficiency in pure QCS system, whereas the turbidity of the reed pulp suspension increased slightly with the increasing of NaCl concentration in QCS‐SiO2systems. The effect of shear force on the flocculation was tested. It was shown shear led to floc breakage and decreased the flocculation. These phenomena were very obvious for one‐component system (QCS or C‐St), but the microparticle system (QCS‐SiO2or C‐St‐SiO2) was shear resistance. Dynamic drainage experiment indicated that the turbidity of white water was decreased with the increasing of dosage of SiO2in experimental level. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Synthesis and thermal characterization of random poly(butylene terephthalate‐co‐2‐methyl‐ethylene terephthalate) copolyesters
Authors: Wu Fangjuan , Yang Guisheng 
Published: March 2010

AbstractPoly(butylene terephthalate‐co‐2‐methyl‐ethylene terephthalate) (PBT/MET) was synthesized by incorporating 1,2‐propandiol(1,2‐PDO) into PBT chains. The molar composition and chemical structure of PBT/MET copolyesters were confirmed by means of FT‐IR and 1H‐NMR. To investigate the effect of 1,2‐PDO on the thermal properties of PBT/MET copolyesters, the copolymerizations were carried out by varying various contents of MET units, and the prepared materials were evaluated by differential scanning calorimetry and thermogravimetric analysis. Results suggested that with the increase of the content of 1,2‐PDO, the amount of crystallinity and the melting temperature decline, while the glass transition temperature increases and the copolyesters become more transparent and brittle with respect to PBT homopolymer. In addition, the Tg‐composition and Tm‐composition data are well subjected to the Wood equation and Flory's equation, respectively. All these copolyesters are found to consist of the general trend displayed by copolymers reported elsewhere. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Elaboration of superparamagnetic cobalt–ferrite nanocomposites from films of chitosan chelates
Authors: Garza‐Navarro M. A. , González‐González V. A. , Torres‐Castro A. , Hinojosa M. , García‐Loera A. , José‐Yacamán M. 
Published: March 2010

AbstractCobalt–ferrite nanocomposites were synthesized from polymeric films of chelates of Co(II) and Fe(III) ions within a chitosan matrix by a solid‐state coprecipitation reaction with weight content ratios of chitosan to cobalt–ferrite of 50/50 and 25/75 w/w. Morphological and crystalline studies of the composites were performed by high‐resolution transmission electron microscopy, X‐ray diffraction, and selected area electron diffraction with a nanobeam diffraction probe. The results show nanoparticles around 4 nm with a spinel structure, consistent with the cobalt–ferrite phase. The magnetic behavior was evaluated with curves of the applied‐field‐dependent magnetization [M(H)] and the temperature‐dependent magnetization [M(T)]. Both theM(H) andM(T) curves showed typical superparamagnetic behavior, depicting an absence of hysteretic characteristics and the characteristic peak at blocking temperature in the zero‐field‐cooled curve. There was also evidence of strong interparticle and intraparticle interactions, which suggested magnetic frustration in the particle magnetic moment alignment with the applied field. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Novel comb‐structured‐polymer‐grafted carbon black by surface‐initiated atom transfer radical polymerization and ring‐opening polymerization
Authors: Yang Qiang , Wang Li , Huo Jia , Ding Jianhua , Xiang Weidong 
Published: March 2010

AbstractNovel comb‐structured‐polymer‐grafted carbon black (CB) was synthesized with a combination of surface‐initiated atom transfer radical polymerization and ring‐opening polymerization. First, poly(2‐hydroxyethyl methacrylate) (PHEMA) was grafted onto the CB surface by surface‐initiated atom transfer radical polymerization. The prepared CB‐g‐PHEMA contained 35.6–71.8% PHEMA, with the percentage depending on the molar ratio of the reagents and the reaction temperature. Then, with PHEMA in CB‐g‐PHEMA as the macroinitiator, poly(ϵ‐caprolactone) (PCL) was grown from the CB‐g‐PHEMA surface by ring‐opening polymerization in the presence of stannous octoate. CB‐g‐PHEMA and CB‐g‐(PHEMA‐g‐PCL) were characterized with Fourier transform infrared, 1H‐NMR, thermogravimetric analysis, dynamic light scattering, and transmission electron microscopy. The resultant grafted CB had a shell of PHEMA‐g‐PCL. On the whole, the CB nanoparticles were oriented in dendritic lamellae formed by these shells. This hopefully will result in applications in gas sensor materials and nanoparticle patterns. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Swelling characteristics of poly(N‐isopropylmethacrylamide‐co‐itaconic acid) gels prepared in various conditions
Authors: Vakıflı Ayşe , Demirel Gökçen Birlik , Caykara Tuncer 
Published: March 2010

AbstractThermo‐ and pH‐sensitive gels composed of N‐isopropylmethacrylamide (NIPMA) and itaconic acid (IA) were prepared by free‐radical crosslinking copolymerization in poly(ethylene glycol) (PEG) solution at 22°C and in water at −22°C and at 22°C, which were called as the macroporous gel (MGel), the cryogel (CGel), and the conventional gel (NGel), respectively. The gels were characterized by the equilibrium swelling, interior morphology, and deswelling kinetics. With increasing temperature in water, the gels exhibit reentrant conformational phase transition. During this transition, the gels first deswell in the range of temperature between 5 and 29°C, then drastically reswell if temperature is monotonically increased. The reswelling of the collapsed gels occurs above 45°C. It was shown that the reentrant transition in poly(N‐isopropylmethacrylamide‐co‐itaconic acid) [poly(NIPMA‐co‐IA)] gels requires moderate temperature, so that the hydrophobic interactions between chains dominate the swelling process. Scanning electron micrographs revealed that the interior network structure of MGel is more porous compared with those of CGel and NGel. This more porous structure provided numerous water channels for water diffusion out of the matrix and, therefore, an improved response rate to the external temperature and pH changes during the deswelling process. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Miscibility, crystallization kinetics, and mechanical properties of poly(3‐hydroxybutyrate‐co‐3‐hydroxyvalerate)(PHBV)/poly(3‐hydroxybutyrate‐co‐4‐hydroxybutyrate)(P3/4HB) blends
Authors: Wang Xiaojuan , Chen Zhifei , Chen Xianyu , Pan Jueyu , Xu Kaitian 
Published: March 2010

AbstractPoly(3‐hydroxybutyrate‐co‐3‐hydroxyvalerate)(PHBV)/poly(3‐hydroxybutyrate‐co‐4‐hydroxybutyrate) (P3/4HB) blend films were prepared by solvent‐cast method. The nonisothermal crystallization results showed that PHBV and P3/4HB are miscible due to a single glass transition temperature (Tg), which is dependent on blend composition. The isothermal crystallization results demonstrate that the crystallization rate of PHBV becomes slower after adding amorphous P3/4HB with 19.2 mol% 4HB, which could be proved through depression of equilibrium melt point ($T_m^o$) from 183.7°C to 177.6°C. For pure PHBV and PHBV/P3/4HB (80/20) blend, the maximum crystallization rate appeared at 88°C and 84°C, respectively. FTIR analysis showed that PHBV/P3/4HB blend films would maintain the helical structure, similar to pure PHBV. Meanwhile, with increasing P3/4HB content, the inter‐ and intra‐interactions of PHBV and P3/4HB decrease gradually. Besides, a lower elastic modulus and a higher elongation at break were obtained, which show that the addition of P3/4HB would make the brittle PHBV to ductile materials. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Mechanical properties of poly(ether ether ketone)/poly(ether ketone) blends: Use of simple models relating normalized tensile parameters
Authors: Mandal Subhash , Alam Sarfaraz 
Published: March 2010

AbstractIn this study, mechanical properties such as tensile properties, flexural properties, and Izod impact strength of poly(ether ether ketone) (PEEK) and poly(ether ketone) (PEK) blends at PEK concentration from 0 to 0.42 volume fraction were studied. The blends of PEEK and PEK of different compositions were prepared by extrusion in a single‐screw extruder. With increase in the PEK concentrations, the tensile strength, flexural strength, and modulus increased whereas the tensile modulus and the impact strength decreased. Homogeneous dispersion and adhesion of PEK in PEEK was shown by the morphological studies. Crystallinity of blends influenced the tensile modulus and the impact strength. Using simple models to relate normalized tensile parameters where the data were divided by the crystallinity of the blends and of the PEEK matrix, respectively, supported the experimental results. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Structure and antimicrobial activity relationship of quaternary N‐alkyl chitosan derivatives against some plant pathogens
Authors: Badawy Mohamed E. I. 
Published: March 2010

AbstractIn the present work, quaternary chitosans as water‐soluble compounds were prepared based on three‐step process. Schiff bases were firstly synthesized by the reaction between the amino groups of chitosan with aliphatic aldehydes followed by a reduction with sodium borohydride (NaBH4) to form N‐(alkyl) chitosans. N,N,N‐(dimethyl alkyl) chitosans were then obtained by a reaction of chitosan containing N‐butyl, N‐pentyl, N‐hexyl, N‐heptyl, and N‐octyl substituents with methyl iodide. The compounds were characterized using IR and NMR spectroscopy. Subsequent experiments were conducted to test their antimicrobial activities against the most economic plant pathogenic bacteria of crown gall disease Agrobacterium tumefaciens, soft mold disease Erwinia carotovora, fungi of grey mold Botrytis cinerea, root rot disease Fusarium oxysporum, and damping off disease Pythium debaryanum. Quaternary chitosans enhanced the antibacterial activity and N,N,N‐(dimethyl pentyl) chitosan was the most active one with Minimum Inhibitory Concentration (MIC) of 750 and 1225 mg/L against A. tumefaciens and E. carotovora, respectively. All quaternized chitosans gave stronger antifungal activities than chitosan where N,N,N‐(dimethyl pentyl) chitosan and N,N,N‐(dimethyl octyl) chitosan were significantly the highest in mycelial growth inhibiation against B. cinerea (EC50 = 908 and 383 mg/L, respectively), F. oxysporum (EC50 = 871 and 812 mg/L, respectively), and P. debaryanum (EC50 = 624 and 440 mg/L, respectively). In addition, spore germination of B. cinerea and F. oxysporum was significantly affected with the compounds at the tested concentrations and the inhibition activity was increased with an increase in the chain length of the alkyl substituent. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Synthesis and characterization of polypyrrole dodecylbenzenesulfonate‐titanium dioxide nanocomposites
Authors: Shakoor Abdul , Rizvi Tasneem Zahra 
Published: March 2010

AbstractNanocomposites of polypyrrole dodecylbenzenesulfonate‐titanium dioxide have been prepared from a colloidal solution of titanium dioxide (TiO2) nanoparticles. The DC conductivity of samples with different concentrations of TiO2 has been investigated under dark and light. The doping effect of TiO2 has been characterized and evaluated by transmission electron microscopy (TEM), Fourier transform infrared spectroscopy, and X‐ray diffraction. TEM shows that TiO2 nanoparticles have strong effects on the morphology of composites, and conductivity measurements show that the conductivity first increases and then decreases as the percentage of TiO2 is increased in the composites exhibiting a maximum in conductivity at about 20 wt % of TiO2. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Telechelic siloxanes with hydrogen‐bonded polymerizable end‐groups. II. IR studies of end‐groups interactions—Model amides and ureas
Authors: Mazurek M. , Leir C. M. , Galkiewicz R. K. 
Published: March 2010

AbstractHydrogen‐bonding phenomena in amides and ureas are of great practical and theoretical importance. In this article, we report on infrared temperature studies aimed at the elucidation of the hydrogen‐bonding phenomena of (meth)acrylamide groups directly linked to the alkyl groups of telechelic polydimethylsiloxane (PDMS) which serve as models of monoamides, or linked to the alkyl groups of telechelic PDMS through amide spacers‐models of diamides (dipeptides). Similarly, we have examined the hydrogen‐bonding phenomena in urea‐terminated telechelic PDMSs to which free‐radically polymerizable groups (methacrylate, α‐methylstyryl) are attached. Hydrogen bonding in the derivatives of these substituted silicone amides and ureas in the unreacted (liquid) state has been studied, as well as in films formed via ultraviolet‐initiated free‐radical polymerization of those reactive end‐groups. The extreme flexibility of the silicones provides a medium in which polar, hydrogen‐bonding end‐groups (amides, diamides, and ureas) phase‐separate to form their own domains wherein they can freely aggregate in an essentially unperturbed state, when in the liquid form. When the vinyl end‐groups are polymerized, interactions between the hydrogen bonding groups attached to them can be studied in a spatially constrained environment. High thermal stability of the silicones allows the study of the hydrogen bonding (H‐bonding) phenomena of these models within a broad temperature range. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Preparation and physico‐mechanical, thermal and acoustic properties of flexible polyurethane foams based on hydroxytelechelic natural rubber
Authors: Saetung Anuwat , Rungvichaniwat Adisai , Campistron Irène , Klinpituksa Pairote , Laguerre Albert , Phinyocheep Pranee , Doutres Olivier , Pilard Jean‐François 
Published: March 2010

AbstractNovel flexible polyurethane foams were successfully prepared from a renewable source, hydroxytelechelic natural rubber (HTNR) having different molecular weights (1000–3400 g mol−1) and variation of epoxide contents (EHTNR, 0–35% epoxidation) by a one‐shot technique. The chemical and cell structures as well as physico‐mechanical, thermal, and acoustic properties were characterized and compared with commercial polyol analogs. The obtained HTNR based foams are open cell structures with cell dimensions between 0.38 and 0.47 mm. The HTNR1000 based foam exhibits better mechanical properties but lower elongation at break than those of commercial polyol analog. However, the HTNR3400 based foam shows the best elastic properties. In a series of EHTNR based foams, the tensile and compressive strengths show a tendency to increase with increasing epoxide content and amount of 1,4‐butanediol (BD). The HTNR based foams demonstrate better low temperature flexibility than that of the foam based on commercial polyol. Moreover, the HTNR based polyurethane foams was found to be an excellent absorber of acoustics. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Effect of the structure at the micrometer and nanometer scales on the light transmission of isotactic polypropylene
Authors: Zia Qamer , Androsch René , Radusch Hans‐Joachim 
Published: March 2010

AbstractThe spherulitic superstructure, crystallinity, and structure and morphology of crystals of isotactic polypropylene were controlled by the conditions of melt crystallization and related to the transmittance of visible light. Spherulitic samples, which contained monoclinic lamellae, were prepared by slow cooling of the quiescent melt at rates lower than 10 K/s and by isothermal melt crystallization at temperatures between 373 and 413 K. Nonspherulitic specimens, which contained nonlamellar mesomorphic domains, in contrast, were obtained by rapid cooling of the melt with rates faster than 100 K/s. The crystallinity and the size of crystals were furthermore fine‐tuned by subsequent annealing at elevated temperatures. Analysis of such films of different structure by ultraviolet–visible spectroscopy revealed that the light transmission was independent of (1) the fraction, (2) the internal structure, and (3) the size of the crystals. In contrast, the light transmission increased with decreasing size of spherulites and finally exceeded 90% in films of 100 μm thickness when spherulites were completely absent. The crystallinity and the structure and size of the crystals of the films of isotactic polypropylene could be adjusted within wide limits without affecting the light transmission. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Aspects of network formation in glassy thermosets
Authors: Detwiler Andrew T. , Lesser Alan J. 
Published: March 2010

AbstractAspects of network formation and the physical properties of stoichiometric amine‐cured epoxy resins are investigated. The state of network formation is systematically controlled by using isothermal cure conditions and a linear temperature ramp condition. Affine deformation in compression at a constant true strain rate is used to measure the true stress–strain response from small strains to large strains. Beginning with the low‐strain responses and continuing through yielding, partially cured samples demonstrate characteristics of physical ageing that diminish as the networks approach full conversion. The postyield properties are characterized by a strong dependence on network connectivity with little influence of the curing method. The mechanical responses are also applied to necking and shear banding analyses. The resins are unable to achieve stable necking in tension. However, shear bands are able to be stabilized, as predicted by a model developed in this work. These results suggest that physical ageing is inherent in epoxy network formation, and the resulting strain localization significantly degrades the mechanical integrity of epoxy resins in the partially cured state, regardless of the cure conditions. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Measurement of the pressure dependence of viscosity of polymer melts using a back pressure‐regulated capillary rheometer
Authors: Aho Johanna , Syrjälä Seppo 
Published: March 2010

AbstractThe effect of pressure on the melt viscosity was experimentally investigated for five polymers: polycarbonate (PC), acrylonitrile‐butadiene‐styrene (ABS), polystyrene (PS), polypropylene (PP), and low‐density polyethylene (LDPE). Measurements were carried out using capillary rheometer modified to allow regulation of back pressure. To enable correction for the entrance pressure drop, two round‐hole dies were used: a 1‐mm diameter die of length 10 mm and an orifice die of the same diameter. For determining the pressure coefficient from the experimental viscosity data, time‐pressure superposition was applied to generate a master curve to which the Carreau‐Yasuda model was fitted. The resulting pressure coefficients revealed that for the polymers studied the order of the degree of the pressure dependence is as follows: PS > ABS > PC > PP > LDPE. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010