bluuebunny/crossref_metadata_2025_split huggingface dataset:
Mapping of MRX81 in Xp11.2‐Xq12 suggests the presence of a new gene involved in nonspecific X‐linked mental retardation
Authors: Annunziata Ida , Lanzara Carmela , Conte Ivan , Zullo Alberto , Ventruto Valerio , Rinaldi Maria Michela , D'Urso Michele , Casari Giorgio , Ciccodicola Alfredo , Miano Maria Giuseppina 
Published: March 2003

AbstractX‐linked nonspecific mental retardation (MRX) accounts for ∼25% of mental retardation in males. A number of MRX loci have been mapped on the X chromosome, reflecting the complexity of gene action in central nervous system (CNS) specification and function. Eleven MRX genes have been identified, but many other causative loci remain to be refined to the single gene level. In 21 MRX families, the causative gene is located in the pericentromeric region; and we report here the identification by linkage analysis of a further such locus, MRX81. The new MRX locus was identified by two‐ and multi‐point parametric analysis carried out on a large Italian family. Tight linkage of MRX81 to DNA markers ALAS2, DXS991, and DXS7132 was observed with a maximum LOD score of 3.43. Haplotype construction delineates an MRX81 critical region of 8 cM, the smallest MRX pericentromeric interval so far described, between DXS1039 and DXS1216, and placing it in Xp11.2‐Xq12. So far, automated sequencing of two candidates in the region, the MRX gene oligophrenin (OPHN1) and the brain‐specific ephrinB1 (EFNB1) gene, in DNA from affected males excluded their candidacy for MRX81, suggesting a novel disease gene. © 2003 Wiley‐Liss, Inc.
Mechanism of intrachromosomal triplications 15q11‐q13: A new clinical report
Authors: Vialard François , Mignon‐Ravix Cécile , Parain Dominique , Depetris Danielle , Portnoï Marie‐France , Moirot Hélène , Mattei Marie‐Geneviève 
Published: March 2003

AbstractWe describe here a patient with intrachromosomal triplication 15q11‐q13, a rare chromosomal event associated with severe mental retardation and intractable epilepsy. Cytogenetic studies including FISH on interphasic nuclei showed that the middle segment of the triplication was inverted in orientation. Molecular analyses demonstrated that the rearrangement was of maternal origin. Based on these cytogenetic and molecular data and those of the nine cases reported in the literature, we discuss the mechanistic origins of these triplications. We present several arguments for the mechanism involving two U‐type exchanges occurring simultaneously at the pachytene stage of meiosis. © 2003 Wiley‐Liss, Inc.
Effective monosomy or trisomy of chromosome band 2q37.3 due to the unbalanced segregation of a 2;11 translocation
Authors: Batstone Paul J. , Simpson Sheila , Bonthron David T. , Keng Wee T. , Hamilton Doreen , Forsyth Linda , Sales Mark , Pratt Norman , Goudie David 
Published: March 2003

AbstractWe report a seven generation family in which a 2;11 chromosome translocation is segregating. Both unbalanced segregants have been found in the family, and cytogenetic analysis demonstrates that this results in effective monosomy or trisomy for chromosome band 2q37.3. Those family members who are monosomic exhibit a variable phenotype with a number of features associated with an Albright's Hereditary Osteodystrophy‐like phenotype (AHO‐like) whilst those who are trisomic have a phenotypic spectrum ranging from mild facial anomalies and growth retardation to apparent normality. The latter group of patients represent the first reported patients with pure trisomy for chromosome band 2q37.3. © 2003 Wiley‐Liss, Inc.
Characterization of a chromosome 8‐derived minute marker chromosome using microdissection and FISH in a boy with growth retardation
Authors: Engelen J.J.M. , Schrander‐Stumpel C.T.R.M. , Theunissen P.M.V.M. , Vaes‐Peeters G. , Albrechts J.C.M. , Hamers A.J.H. 
Published: March 2003

AbstractIn a 9‐year‐old boy referred because of growth retardation, chromosome analysis showed the presence of a minute marker chromosome in 75% of the metaphases examined. The application of microdissection in combination with fluorescence in situ hybridization demonstrated that the marker was derived from the centromere region of chromosome 8, the karyotype being: mos 47,XY,+mar.ish der(8)(D8Z1+)[75]/46,XY[25]. The clinical and cytogenetical findings are compared with cases previously reported in the literature. © 2003 Wiley‐Liss, Inc.
Behavioral assessment of children with Down syndrome using the Reiss psychopathology scale
Authors: Clark Debbie , Wilson Golder N. 
Published: March 2003

AbstractThe behavior of 60 children with Down syndrome (cDS), aged 4 to 21 years, was assessed by parent and teacher report using the Reiss psychopathology rating scale for dual diagnosis (mental disability plus mental illness). Standard forms contained 12 categories of abnormal behavior (e.g., Psychosis), each with five descriptive items (e.g., bizarre ideas) that could be scored as no problem, problem, and major problem (0, 1, or 2 points). Total scores for individual cDS (mean of two raters) ranged from 3 to 43 out of a potential 120 points, with a mean of 14.8 points and a standard deviation of 9.5. There were no significant differences by sex, age, or ethnicity. The highest aggregate scores among the 60 cDS were in the psychometric categories of Attention‐Deficit (156 points), Anger/Self Control (154.5), and Psychosis (109) and for component items such as communication problems (55 points) under the Psychosis category; distracted (48.5) or disobedient (42.5) under the Attention‐Deficit category; and temper tantrums (36.5), impulsive (32), or impatient (31.5) under the Anger/Self‐Control category. Agreement between parent and teacher raters was over 75% for 38 of the 60 items and above 60% for an additional 15. Selection of cDS with scores over 10 points yielded 24 families who chose parental guidance and 14 who chose professional referral. The structure of the Reiss instrument was useful for cDS, distinguishing behaviors potentially related to medical problems from true psychopathology. © 2003 Wiley‐Liss, Inc.
Stocco dos Santos X‐linked mental retardation syndrome: Clinical elucidation and localization to Xp11.3–Xq21.3
Authors: Stocco dos Santos Rita C. , Castro Nelson H.C. , Lillia Holmes A. , Beçak Willy , Tackels‐Horne Darci , Lindsey Charles J. , Lubs Herbert A. , Stevenson Roger E. , Schwartz Charles E. 
Published: March 2003

AbstractMental retardation (MR) affects an estimated 2–3% of the population. A considerable fraction of mental retardation is due to X‐linked genes. Of these genes, about 136 are responsible for syndromic X‐linked MR (XLMR). One such XLMR syndrome, Stocco dos Santos, was first described in 1991. This family was re‐visited, which allowed further delineation of the clinical phenotype. Additionally, linkage analysis was conducted, which resulted in the localization of this XLMR syndrome to the pericentric region, Xp11.3 to Xq21.1, with a maximum LOD score of 3.14 at loci AR and DXS983. © 2003 Wiley‐Liss, Inc.
Synthesis and swelling behavior of crosslinked copolymers of neutralized maleic anhydride with other monomers
Authors: You Ying‐Cai , Jiao Jing‐Liang , Li Zhen , Zhu Chang‐Ying 
Published: March 2003

AbstractA series of novel copolymer superabsorbents based on maleic anhydride (MLN), acrylamide (AAM), hydroxyethyl methacrylate (HEMA), and N,N′‐methylenebisacrylamide (NMBA) were prepared by inverse‐suspension polymerization. The influence of the reaction parameters on the water absorption was investigated to improve the understanding and to identify the optimum reaction conditions. The water absorbences or swelling behaviors for these absorbents in various salt solutions and various alcohol solutions were studied. The tendency of the absorbency for these absorbents in salt and alcohol solutions is in the order Na+ > Ca2+ > Al3+ for NaCl, CaCl2, and AlCl3 aqueous solutions and a glycerol > glycol > methanol > ethanol solution, respectively. This article also explains the IR and SEM characterization of the water‐absorbing copolymers and their practical use in soil for water retention. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 12: 2725–2731, 2003
Preparation and properties of polydimethylsiloxane/polyacrylate composite latex initiated by 60Co γ‐ray irradiation
Authors: Dai Qiu , Zhang Zhicheng , Wang Feng , Liu Jie 
Published: March 2003

AbstractIn this study, polydimethylsiloxane (PDMS)/polyacrylate composite polymer latex was synthesized via polymerization of the acrylate monomer in the presence of vinyl‐containing PDMS seeded latex. The polymerization was initiated by 60Co γ‐ray irradiation. The morphology of the PDMS/polyacrylate composite polymer latex was a core–shell structure with PDMS as the core and polyacrylate as the shell. There was an interpenetration layer between the PDMS core and the polyacrylate shell. The composition of the vinyl‐containing PDMS and the PDMS/polyacrylate composite latex were investigated with NMR and Fourier transform infrared spectroscopy, respectively. The effect of irradiation dose on the seeded emulsion polymerization conversion is discussed. Finally, the mechanical properties of latex film, such as water‐absorption ratio, tensile strength, pendulum hardness, and heat‐decomposed temperature, were tested. The results showed that the mechanical properties of the PDMS/polyacrylate film were remarkably improved when compared to the polyacrylate film. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 2732–2736, 2003
Thermal characterization of butadiene–isoprene copolymers with a 1,2/3,4 structure
Authors: Bertini Fabio , Canetti Maurizio , De Chirico Aurelio , Ricci Giovanni 
Published: March 2003

AbstractTwo series of butadiene–isoprene copolymers with a 1,2 and/or 3,4 structure were prepared at different polymerization temperatures, using CrCl2(dmpe)2‐MAO as a catalyst system. Copolymerization carried out at higher temperature resulted in polymers in the whole range of monomeric ratio, from the highly crystalline 1,2‐syndiotactic polybutadiene to the amorphous 3,4‐polyisoprene. The molar composition of the butadiene–isoprene copolymers and the syndiotactic index of the butadiene sequences, represented as molar fraction of the syndiotactic pentads, were evaluated by carbon‐13 nuclear magnetic resonance spectroscopy. The thermal behavior of the copolymers was investigated by differential scanning calorimetry. Nonisothermal crystallization kinetics were characterized by Ziabicki and Avrami methods as modified by Jeziorny. The crystallization and melting temperatures and the enthalpy of fusion of the copolymers were in good correlation with the syndiotactic index of butadiene sequences. The index was influenced by polymerization temperature and composition of butadiene–isoprene copolymers. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 12: 2737–2743, 2003
Poly(para‐dioxanone) and poly(L‐lactic acid) blends: thermal, mechanical, and morphological properties
Authors: Pezzin A. P. T. , Van Ekenstein G. O. R. Alberda , Zavaglia C. A. C. , Ten Brinke G. , Duek E. A. R. 
Published: March 2003

AbstractBlends of two semicrystalline polymers, poly(L‐lactic acid) (PLLA) and poly‐p‐dioxanone (PPD) have been prepared by solvent casting in different compositions. Thermal, morphological, and mechanical properties of the blends were studied using modulated differential scanning calorimetry, wide‐angle X‐ray diffractometry, scanning electron microscopy (SEM), polarizing light microscopy (PLM), and tensile tests. Thermal analysis showed two glass transition temperatures nearly constant and equal to the values of the homopolymers and constant values of melting temperature (Tm) for all blend compositions, suggesting that both polymers are immiscible. The PLM and SEM observations validated these results, and showed the different morphology obtained by changing the composition of the blend. The blends 40/60, 50/50, and 60/40 presented a clearly macroseparated system, while the 20/80 and 80/20 blends presented better homogeneity, probably due to the low amount of one component in the other. It was found by PLM that PPD is able to crystallize according to a spherulitic morphology when its content is above 40%. Under this content, the crystallization of PPD is hardly observed. The blend 20/80 is more flexible, and tough material and neck formation during elongation is also observed, due to PPD, which may act as a plasticizer. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 12: 2744–2755, 2003
Synthesis and rapid expansion in supercritical carbon dioxide through porous sintered metal plate of poly(1,1,2,2‐tetrahydroperfluorodecyl acrylate)
Authors: Dong Qingzhi , Young Thomas M. 
Published: March 2003

AbstractPoly(1,1,2,2‐tetrahydroperfluorodecyl acrylate) [poly(TA‐N)] was synthesized in dry benzene using AIBN as an initiator at 60°C. The effects of the monomer concentration (Cm), initiator concentration (Ci), and reaction time on the polymerization were investigated. The results of DSC and TGA showed that when the Ci remains constant, the higher the Cm value is, the better the thermal character for the product in the range of experiments. When the reaction was conducted for 30 h, polymerization is almost completed. The Ci should remain lower than 0.25 g/100 g monomer when the Cm is lower than 15 g/L. When the Cm is higher than 15 g/L, the Ci should be increased slightly. When the Cm remains constant, it was observed that an increase in the Ci increases the yield (mass of polymer after reaction/mass of monomer before reaction). On the other hand, the melting (Tm) and decomposition (Td) temperatures of the reaction product decrease, except when the Cm reaches 20 g/L and the reaction time is 30 h. High purity CO2 was continuously pumped using a high pressure syringe pump. Rapid expansion of poly(TA‐N) in supercritical CO2 happened under control through a porous sintered metal plate. The poly(TA‐N) morphology was analyzed with a scanning electron microscope. An amorphous polymer was formed at a preexpansion temperature of 45°C. Fibers were formed at temperatures of around 60–80°C. An increase of the temperature slightly increases the particle size. At 105°C, most of the particles are spheres and dendrites. The corresponding CO2 flow rate upon expansion was 2.5–5.0 ± 0.3 L/min (STP) and the pressure drop was 2 MPa. At the higher CO2 flow rate, the spheres and dendrites became smaller. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 2763–2768, 2003
Depolymerized chitosan nanoparticles for protein delivery: Preparation and characterization
Authors: Janes K. A. , Alonso M. J. 
Published: March 2003

AbstractIn this article we describe our preliminary work involving the use of depolymerized, low molecular weight chitosan nanoparticles as carriers for proteins and peptides. We hypothesized that the molecular weight of chitosan could favorably modulate the particle and protein release characteristics for the delivery of certain bioactive macromolecules. Our primary objectives were to develop nanoparticle formulations that were stable and reproducible across a range of chitosan molecular weights and then characterize the physicochemical and in vitro release properties as functions of the polymer size. Using depolymerized fragments generated by NaNO2 degradation of different chitosan salts, we prepared nanoparticle formulations based on ionotropic gelation with sodium tripolyphosphate (TPP). Regardless of the formulation, the nanoparticle size decreased with decreasing molecular weight and the ζ‐potential values remained unchanged. Similar comparisons were made with the encapsulation of insulin and tetanus toxoid as model proteins. The results indicated that the quantity of TPP in a given formulation has a greater effect on the protein encapsulation than the chitosan molecular weight. In fast release environments (i.e., buffered media), there was no significant molecular weight effect that could be discerned. These data lead to the conclusion that, under these experimental conditions, the chitosan molecular weight has a measurable effect on the particle properties, although this effect is modest relative to other formulation parameters (e.g., TPP content, type of protein loaded). Because these subtle differences could have dramatic effects physiologically, work is currently underway to elucidate the possible applications of depolymerized chitosans for peptide delivery in vivo. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 12: 2769–2776, 2003
Antibacterial and biodegradable properties of polyhydroxyalkanoates grafted with chitosan and chitooligosaccharides via ozone treatment
Authors: Hu S.‐G. , Jou C.‐H. , Yang M.‐C. 
Published: March 2003

AbstractAcrylic acid was grafted to ozone‐treated poly(3‐hydroxybutyric acid) (PHB) and poly(3‐hydroxybutyric acid‐co‐3‐hydroxyvaleric acid) (PHBV) membranes. The resulting membranes were further grafted with chitosan (CS) or chitooligosaccharide (COS) via esterification. These CS‐ or COS‐grafted membranes showed antibacterial activity against Escherichia coli, Pseudomonas aeruginosa, methicilin‐resistant Staphylococcus aureus (MRSA), and S. aureus. The antibacterial activity to E. coli was the highest, whereas the antibacterial activity to MRSA was the lowest among these four bacteria tested. Acrylic acid grafting can increase the biodegradability with Alcaligens faecalis, whereas CS and COS grafting can reduce the biodegradability. In addition, CS‐grafted PHBV membrane showed higher antibacterial activity and lower biodegradability than COS‐grafted PHBV membrane. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 12: 2797–2803, 2003
Effects of rosin‐type nucleating agent and low density polyethylene on the crystallization process of polypropylene
Authors: Li Chuncheng , Li Wei , Wang Hui , Zhang Dong , Li Zhenyi 
Published: March 2003

AbstractIn this article, the influence of rosin‐type nucleating agent (Nu–Na) and low density polyethylene (LDPE) on the crystallization process of polypropylene (PP) from the melt state was studied by differential scanning calorimeter and polarization microscope. It was found that LDPE obstructed the crystallization of PP, decreased the crystallization rate of PP. The rosin‐type nucleating agent Nu–Na substantially improved the rate of crystallization, and decreased the size of spherulites also. The cooperative effect of LDPE and Nu–Na made the crystallization rate of PP increase greatly, the spherulites of PP became much smaller and dispersed more uniformly, and the transparency of PP was further improved evidently. The crystallization temperature (Tc) and melting temperature (Tm) of PP and LDPE in PP/LDPE/Nu–Na (97:3:0.5) were not affected by the number of mixed passes—the nuclei migration from PP to PE had not happened in the mixed passes. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 2804–2809, 2003
Influence of temperature on the ultrasonic degradation of poly(vinyl acetate) and poly(vinyl chloride)
Authors: Chattopadhyay Sujay , Madras Giridhar 
Published: March 2003

AbstractThis study investigates the effect of temperature on the ultrasonic degradation of polyvinyl acetate and polyvinyl chloride in chlorobenzene. The time evolution of molecular weight distribution was determined using gel permeation chromatography. Continuous distribution kinetics was used to obtain the degradation rate coefficients. The rate coefficients decrease with increasing temperature, and this is attributed to the increase of vapor pressure and the decrease of kinematic viscosity. The degradation rate coefficient also changes sharply near the glass transition temperature, indicating that this factor may play a role in the degradation process. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 12: 2818–2822, 2003
Thin copper foil heater for measuring the thermal conductivity of polymers
Authors: Kazeminejad H. 
Published: March 2003

AbstractA new and rather simple apparatus is described for measuring the thermal conductivity of insulating materials. The technique employs a double‐sided, copper‐coated plastic sheet, known as a printed circuit board, to generate a nearly uniform wall heat flux. Heating is achieved by passing an electrical current through the copper coating. Identical sample slabs are placed against opposite sides of the heater, and the combination is placed in a bath having constant and uniform temperature. When thermal equilibrium is reached, the temperature drops across the central portions of the sample slabs are measured with thermocouples. The one‐dimensional form of Fourier heat transfer equation is used to compute thermal conductivity from the observed quantities. In preliminary tests with polymer materials, equilibrium is reached within half an hour. It is estimated that the apparatus is capable of giving measurements accurate to within 5%, and experimental results are consistent with this estimate. Thermal conductivity values are reported for pure polyethylene (PE) and PE mixed with aluminum powder and carbon black. Also reported is the thermal conductivity of pure polycarbonate (PC) and PC mixed with carbon black. The results obtained with the present apparatus are consistent with previous findings. The characteristics of the apparatus make it especially suitable for academic laboratory instruction and for low temperature thermal conductivity measurements. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 12: 2823–2827, 2003
Surface chemistry and moisture sorption properties of wood coated with multifunctional alkoxysilanes by sol‐gel process
Authors: Tshabalala Mandla A. , Kingshott Peter , VanLandingham Mark R. , Plackett David 
Published: March 2003

AbstractSol‐gel surface deposition of a hydrophobic polysiloxane coating on wood was accomplished by using a mixture of a low molecular weight multifunctional alkoxysilane, methyltrimethoxysilane (MTMOS), and a high molecular weight multifunctional alkoxysilane, hexadecyltrimethoxysilane (HDTMOS). Investigation of the surface chemistry and morphology of the wood specimens by means of ATR–FTIR, energy‐dispersive X‐ray analysis, X‐ray photoelectron spectroscopy, SEM, and atomic force microscopy indicated that the sol‐gel process results in deposition of polysiloxane networks that are bonded to the wood by polycondensation with surface hydroxyl groups. The surface hydroxyl groups involved in the bonds appear to be located predominantly on the cellulose component of the wood. The sol‐gel deposit on the wood substrates lowered the rates of water and water vapor sorption. The low molecular weight MTMOS apparently penetrated the outer surface layers of the wood and condensed with hydroxyls that may not be readily accessible to the high molecular weight HDTMOS. Once attached to such sites, it is reasonable to assume that some of these surface derivatives of MTMOS condensed with other molecules of MTMOS and HDTMOS with a long hydrocarbon chain to form a polysiloxane network that is hydrophobic. The ultimate effect of the sol‐gel deposit can therefore be regarded as not only to decrease the surface concentration of hydrogen‐bonding sites, but also to stereochemically hinder the formation of hydrogen bonds between such sites and water molecules. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 2828–2841, 2003