bluuebunny/crossref_metadata_2025_split huggingface dataset:
Preparation of a porous structure in a poly(4‐methyl‐1‐pentene)/diphenyl ether system with a thermally induced phase‐separation method
Authors: Zhang Qiang , Zhang Youquan , Xia Dewan , Zhao Yun , Shi Yanqiao , Jiao Qingze 
Published: January 2009

AbstractPoly(4‐methyl‐1‐pentene) was used to prepare porous structures by a thermally induced phase‐separation method. Different porous structures were obtained with poly(4‐methyl‐1‐pentene), which has excellent properties as a polymer, and diphenyl ether as a diluent. The affecting factors, including the polymer concentration and cooling temperature, are discussed. Scanning electron microscopy images and porosity values were obtained to investigate the affecting factors. According to the cloud‐point temperature and crystallization temperature, a phase diagram was also obtained to explain the phase‐separation process. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Nonisothermal cure kinetics of DGEBA with 2,7‐diaminofluorene
Authors: Ghaemy M. , Barghamadi M. 
Published: January 2009

AbstractCure kinetics of diglycidyl ether of a bisphenol A‐based epoxy resin (DGEBA) with 2,7‐diaminofluorene (DAF) as curing agent have been studied by using nonisothermal differential scanning calorimeter (DSC). The values of apparent activation energy (Ea) of nonisothermal cure reaction were calculated by using isoconversional and nonisoconversional methods. The Ea values of the samples containing stoichiometric amount of 26 phr DAF revealed a dependence on the conversion (α) by the isoconversional method of Flynn–Wall–Ozawa (FWO). The Ea values by nonisoconversional methods of Ozawa and Kissinger–Akahira–Sunose (KAS) were 58.27 and 55.68 kJ/mol, respectively. The cure process showed that the autocatalytic behavior dominates the mechanism in the initial stages where the rate‐controlling steps are located, but becomes diffusion‐controlled in the final stage. Techniques of predicting isothermal cure time from nonisothermal kinetic parameters by ASTM and Vyazovkin methods were used for the cure reaction of DGEBA/DAF system. Thermal stability of the cured resin was also determined by using thermogravimetry analysis (TGA). © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Synthesis and humidity sensitive properties of pyrrole‐based polyelectrolytes
Authors: Lv Xin , Hong Li‐Jie , Li Yang , Yang Mu‐Jie 
Published: January 2009

AbstractPyrrole (Py)‐based polyelectrolytes (Py‐PE): P(Py‐COOLi), P(Py‐COONa), and P(Py‐COOK) was synthesized, characterized, and used to prepare thin film resistive humidity sensors. Their humidity sensitive properties have been investigated, and sensing mechanism was presented. The Py‐PE contains PPy as backbone and the side chain bearing carboxylic salt group, which made its sensor exhibited a very wide humidity sensing range of 0–97% relative humidity (RH), high conductivity even at very low humidity, and both ionic and electronic conduction contributed to its conductivity. Among all the Py‐PE, P(Py‐COOK) showed high sensitivity, with the impedance changing of about three orders of magnitude (103–106 Ω) from 97 to 0% RH, whereas P(Py‐COONa) showed quick response for both absorption (12.5 s) and desorption (15.2 s). Py‐PE prepared is promising for preparation of thin film resistive humidity sensors capable of detecting low humidity. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Fabrication and mechanical properties of glass fiber‐reinforced wood plastic hybrid composites
Authors: Cui Yi‐Hua , Tao Jie 
Published: January 2009

AbstractTo fully utilize the resource in the municipal solid waste (MSW) and improve the strength and toughness of wood plastic composites, glass fiber (GF)‐reinforced wood plastic hybrid composites (GWPCs) were prepared through compounding of recycled high‐density polyethylene (HDPE) from MSW, waste wood fibers, and chopped GF. Mechanical tests of GWPCs specimens with varying amounts of GF content were carried out and the impact fractured surface of GWPCs was observed through scanning electron microscope (SEM). The tensile strength of GWPCs and the efficiency coefficient values were predicted by Kelly‐Tyson method. The results indicated that the tensile strength and impact strength of GWPCs could be improved simultaneously by adding type L chopped GF (L‐GF), and would be dropped down when type S chopped GF (S‐GF) was included. The tensile strength of GWPCs was well accordant with the experimental result. The efficiency coefficient values of S‐GF and L‐GF are −0.19 and 0.63, respectively. Inspection of SEM micrographs indicated that L‐GF had achieved full adhesion with the plastic matrix through addition of maleic anhydride‐g‐polyethylene. The main fracture modes of GWPCs included pullout of GF, broken of matrix, and interfacial debonding. Because of the synergistic effects between hybrid components in GF/wood fiber/HDPE hybrid system, a special 3D network microstructure was formed, which was the main contribution to the significant improvement in the tensile strength and impact strength of L‐GF‐reinforced hybrid composites. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Flocculation of fine particles in ceramic wastewater using new types of polymeric flocculants
Authors: Cengiz Ismail , Sabah Eyup , Ozgen Selcuk , Akyildiz Hatice 
Published: January 2009

AbstractIt appears to be quite a few national and international studies were reported regarding flocculation and settling properties of ceramic industry wastewater containing various mineral matters. Cleaning of ceramic industry wastewaters with ever increasing environmental standards needs effective and economical solid–liquid separation processes. In this study, quantity and type of optimum flocculant concentration were investigated for solid–liquid separation of Umpac ceramic plant (located at Usak, Turkey) wastewaters. A new generation of flocculants namely unique molecular architecture (UMA) are used to obtain high settling velocity along with high solid content waste and circulation water with low turbidity values. Zeta potential of the tailings including quartz, feldspar, clorite, and mica was also measured at different pH values. The flocculation tests were performed in the presence of different types of polymers at different polymer dosages. It seems that Magnafloc 5250 shows higher performance than the anionic flocculant SPK 508 and other anionic UMA flocculants Magnafloc 6260 and Magnafloc 3230. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Benefits of low kenaf loading in biobased composites of poly(L‐lactide) and kenaf fiber
Authors: Ogbomo Sunny M. , Chapman Kent , Webber Charles , Bledsoe Robert , D'Souza Nandika A. 
Published: January 2009

AbstractBast fibers from stems of kenaf (Hibiscus cannabinus, L.), a warm‐season tropical herbaceous annual plant, were dispersed into poly‐L‐lactide (PLLA) matrix by melt‐mixing followed by compression molding. Low fiber fractions (1–5%) were investigated. The composites showed a slight lowering of thermal stability when evaluated by thermogravimentric analysis. X‐ray diffraction and differential scanning calorimetry indicated an influence of kenaf on the crystallization of PLLA. The fiber dispersion in the polymer matrix was established by polarized optical microscopy. Scanning electron microscopy showed good fiber–matrix adhesion as revealed by the combination of dispersion, interaction, and crystallinity, which enabled an increase in the mechanical properties of the composite that scaled with concentration. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Preparation of core‐shell latexes for paper coatings
Authors: Koskinen Mia , Wilén Carl‐Eric 
Published: January 2009

AbstractNovel core‐shell latices with a partially crosslinked hydrophilic polymer core and a hard hydrophobic shell of polystyrene were prepared to improve optical properties of coated paper such as gloss and brightness. These core‐shell latices were prepared by sequential addition of a monomer mixture of styrene, n‐butylacrylate and methacrylic acid. Different crosslinkers were used to form the polymer core and in the second stage styrene to form the hard shell component. In addition, attempts were made to further improve optical properties by introducing a new polymerizable optical brightener, i.e., 1‐[(4‐vinylphenoxy)methyl]‐4‐(2‐phenylethylenyl)benzene during polymerization either into the core or into the shell. The prepared core‐shell latex particles were used as specialty plastic pigments for paper coating together with kaolin as the primary pigment. The runability of paper coating formulation by either using a laboratory scale Helicoater or pilot scale JET‐coating machine was very good. The produced coated papers were printed on both sides employing a heat set web offset (HSWO) printer to study the quality of image reproduction in terms of print gloss, print mottle, print through, etc. The core‐shell latices improved the overall print quality. Furthermore, the results demonstrated that by optimizing polymer composition one can significantly enhance the optical properties and surface smoothness of coated paper. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Deformation and alignment of lamellae in melt extension of blends of a styrene‐butadiene block copolymer with polystyrene
Authors: Handge Ulrich A. , Buschnakowski Matthias , Michler Goerg H. 
Published: January 2009

AbstractThe development of the morphology and the alignment of lamellae in melt elongation of blends of an asymmetric linear styrene‐butadiene block copolymer (LN3) and polystyrene (PS 158K) was investigated. PS 158K and LN3 formed two‐phase polymer blends with PS 158K resp. LN3 inclusions, depending on the concentration of polystyrene. The block copolymer was arranged in a lamellar phase with a lamellae thickness of ∼ 13 nm. Our rheological experiments revealed that the complex modulus, the elongational viscosity and the recovered stretch of the blends primarily resulted from a superposition of the properties of the blend components. In melt elongation, pure LN3 started to crumple at a small Hencky strain. In the blends, the presence of the PS 158K inclusions led to a macroscopically more uniform elongation, but with an anisotropic Poisson ratio. The LN3 inclusions in the PS 158K matrix were deformed into a filament‐like shape. In the blends with a LN3 matrix the alignment of the block copolymer lamellae parallel to the loading direction increased with applied extensional strain. In the latter case, the lamellae thickness did not decrease significantly. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Rheological characterization of UV‐curable epoxy systems: Effects of o‐Boehmite nanofillers and a hyperbranched polymeric modifier
Authors: Corcione Carola Esposito , Frigione Mariaenrica , Acierno Domenico 
Published: January 2009

AbstractAn organo‐modified Boehmite (o‐Boehmite) was used to prepare nanocomposite UV‐curing coatings, based on a cycloaliphatic epoxy resin (3,4‐epoxycyclohexylmethyl‐3′,4′‐epoxycyclohexane carboxylate). A hyperbranched polymer (HBP) based on highly branched polyester, was also added to the resin, with the aim to modify its reactivity, such as a possible route to increase the toughness of the resin. Different amounts of the nanofiller and the HBP, ranging from 5 up to 20 wt % of resin, were dispersed into the resin in the presence of triarylsulfonium hexafluoroantimonate, as a photoinitiator for the UV curing of the resin. The rheological behavior of the formulations produced was studied as function of the shear rate and of the content of each filler using a cone and plate rheometer. A general increase in viscosity was observed with increasing the volume fraction of each filler and a moderate pseudoplastic behavior was observed when o‐Boehmite filler was added. A non‐Newtonian behavior was observed with the incorporation of the HBP. The viscosity of the epoxy/boehmite resin mixtures was analyzed as function of the nanofiller volume fraction. In the case of epoxy/hyperbranched resin mixtures, the Cross equation was used to predict the viscosity of each formulation as a function of the shear rate and an appropriate relationship to predict the viscosity of each formulation as a function of the filler volume fraction, was determined. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Neural tube defects in Australia: Trends in encephaloceles and other neural tube defects before and after promotion of folic acid supplementation and voluntary food fortification
Authors: Bower Carol , D'Antoine Heather , Stanley Fiona J. 
Published: January 2009

AbstractBACKGROUND:Use of periconceptional folic acid supplementation has been promoted in Western Australia since late 1992, and voluntary fortification of some foods with folic acid has been permitted in Australia since 1996. Reduced rates of neural tube defects (NTDs) have been observed since 1995. Aboriginal infants have a higher rate of NTDs, but no fall in rates has been documented. Encephaloceles have not been examined separately.METHODS:Data on anencephaly, spina bifida, and encephalocele were obtained from the Western Australian Birth Defects Registry. The prevalence ratio for each type of NTD was calculated, comparing 1993 to 1995 (promotion of supplements, no fortification) and 1996 to 2006 (promotion of supplements and voluntary fortification) with 1980 to 1992 (no promotion or fortification).RESULTS:From 1996 to 2006, there was a 32% reduction in anencephaly, 23% in spina bifida, and 34% in encephalocele compared with 1980 to 1992. There were no differences seen from 1993 to 1995 compared with 1980 to 1992. For Aboriginal infants, the rates were higher than for non‐Aboriginal infants, for each type of NTD. The prevalence ratios, comparing 1996 to 2006 with 1980 to 1995, were 0.70 (CI, 0.61–0.79) for non‐Aboriginal infants and 0.90 (CI, 0.61–1.32) for Aboriginal infants.CONCLUSIONS:Overall, the rates of encephalocele, anencephaly, and spina bifida have fallen to a similar extent in association with promotion of folic acid supplements and voluntary fortification. No such falls were seen for Aboriginal infants. These data will provide a useful baseline against which to monitor the effects of mandatory fortification on NTDs when it is introduced in Australia in September 2009. Birth Defects Research (Part A), 2009. © 2009 Wiley‐Liss, Inc.
Regulation of folate receptor 1 gene expression in the visceral endoderm
Authors: Salbaum J. Michael , Finnell Richard H. , Kappen Claudia 
Published: January 2009

AbstractBACKGROUND:Nutrient supply to the developing mammalian embryo is a fundamental requirement. Before completion of the chorioallantoic placenta, the visceral endoderm plays a crucial role in nurturing the embryo. We have found that visceral endoderm cells express folate receptor 1, a high‐affinity receptor for the essential micronutrient folic acid, suggesting that the visceral endoderm has an important function for folate transport to the embryo. The mechanisms that direct expression of FOLR1 in the visceral endoderm are unknown.METHODS:Sequences were tested for transcriptional activation capabilities in the visceral endoderm utilizing reporter gene assays in a cell model for extraembryonic endoderm in vitro, and in transgenic mice in vivo.RESULTS:With F9 embryo carcinoma cells as a model for extraembryonic endoderm, we demonstrate that the P4 promoter of the human FOLR1 gene is active during differentiation of the cells towards visceral endoderm. However, transgenic mouse experiments show that promoter sequences alone are insufficient to elicit reporter gene transcription in vivo. Using sequence conservation as guide to choose genomic sequences from the human FOLR1 gene locus, we demonstrate that the sequence termed F1CE2 exhibits specific enhancer activity in F9 cells in vitro, in the visceral endoderm, and later the yolk sac in transgenic mouse embryos in vivo. We further show that the transcription factor HNF4‐alpha can activate this enhancer sequence.CONCLUSIONS:We have identified a transcriptional enhancer sequence from the FOLR1 locus with specific activity in vitro and in vivo, and suggest that FOLR1 is a target for regulation by HNF4‐alpha. Birth Defects Research (Part A), 2009. © 2009 Wiley‐Liss, Inc.
Effects of maternal hyperthermia on myogenesis‐related factors in developing upper limb
Authors: Lee Jin , Mirkes Philip E. , Paik Doo Jin , Kim Won Kyu 
Published: January 2009

AbstractBACKGROUND:Maternal hyperthermia is one causative factor in various congenital anomalies in experimental animals and humans. In the present study, we assessed the effects of high temperature on limb myogenesis in mice.METHODS:Pregnant mice, C57BL/6 strain, were exposed to hyperthermia (43°C, 5 minutes) on embryonic day (ED) 8. Fetuses on ED 11, 13, 15, and 17 and neonates on postnatal day (PD) 1 were collected. To characterize the effects of hyperthermia on myogenesis‐related factors Pax3, MyoD, myogenin, and myosin heavy chain (MyHC) during skeletal muscle development, we performed RT‐PCR, western blotting, immunohistochemistry, and transmission electron microscopy.RESULTS:Pax3 gene expression was still detected on ED 13 in hyperthermia‐exposed fetuses. The expression of MyoD protein was down‐regulated in fetuses exposed to hyperthermia. In contrast, myogenin and MyHC protein expression were up‐regulated on PD 1 and ED 17, respectively, in the group exposed to hyperthermia. Immunohistochemical analysis confirmed the findings from western blot analysis. Compared with control neonates, a TEM study revealed immature muscle fibers in PD 1 hyperthermia neonates. Thus, our studies showed that maternal hyperthermia induced delayed expression of Pax3 and inhibited expression of MyoD proteins, which are known to play important roles in migration of myogenic progenitor cells, and in myoblast proliferation. In addition, maternal hyperthermia also delayed the expression of myogenin protein for the formation of myotubes, and MyHC protein, which is one of the final muscle differentiation factors.CONCLUSION:Our data suggest that maternal hyperthermia delays limb myogenesis in part by disregulating the expression of key myogenesis‐related factors. Birth Defects Research (Part A), 2009. © 2009 Wiley‐Liss, Inc.
Understanding the causes and prevention of neural tube defects: Insights from the splotch mouse model
Authors: Greene Nicholas D.E. , Massa Valentina , Copp Andrew J. 
Published: January 2009

AbstractSplotch mutant mice develop neural tube defects (NTDs), comprising exencephaly and/or spina bifida, as well as neural crest–related defects and abnormalities of limb musculature. Defects in splotch mice result from mutations in Pax3, and some human NTDs may also result from mutations in the human PAX3 gene. Pax3 encodes a transcription factor whose function may influence expression of multiple downstream genes associated with a variety of cellular properties (including apoptosis, adhesion, proliferation, and differentiation), that could be important for neural tube closure. The frequency of NTDs varies between mutant alleles and is also influenced by genetic background and environmental factors. Notably, splotch provides a model for folic acid–preventable NTDs, and conversely, dietary folate deficiency exacerbates NTDs. Understanding the molecular and cellular basis of splotch NTDs, as well as the mechanisms by which the frequency of defects is influenced by genetic and environmental factors (such as sub‐optimal folate status), may provide insight into the causation of these severe congenital malformations in humans. Birth Defects Research (Part A) 2009. © 2009 Wiley‐Liss, Inc.
Maternal serum homocysteine and risk for neural tube defects in a Texas‐Mexico border population
Authors: Felkner Marilyn , Suarez Lucina , Canfield Mark A. , Brender Jean D. , Sun Qin 
Published: January 2009

AbstractBACKGROUND:To better understand the neural tube defect (NTD) causal pathway, the authors measured homocysteine, an indicator of tissue micronutrient deficiencies. The authors examined independent and joint associations of serum homocysteine, B12, and folate and red blood cell (RBC) folate with NTD‐affected pregnancies.METHODS:Case women in this population‐based study had NTD‐affected pregnancies and resided and delivered in one of the 14 Texas‐Mexico border counties from 1995 through 2000. Control women were study area residents delivering normal live births during the same period. The authors measured homocysteine levels using tandem mass spectroscopy; competitive binding was used for other biomarkers.RESULTS:Homocysteine testing was done on 103 cases and 139 controls. Odds ratios (ORs) were increased in all upper homocysteine quintiles compared to the lowest quintile (1.7, 1.3, 2.8, 2.4). Women with high homocysteine values had increased ORs regardless of high versus low levels for B12 (OR = 3.5, 4.8, respectively) or RBC folate (OR = 2.9, 3.5, respectively).CONCLUSIONS:High serum homocysteine levels are associated with NTD‐affected pregnancies. Moreover, high homocysteine levels have a detrimental effect on NTD‐risk even when serum B12 or RBC folate levels are high. Excess homocysteine might play an independent role in the development of NTDs. Birth Defects Research (Part A), 2009. © 2009 Wiley‐Liss, Inc.
Comparative study of clinical characteristics of amniotic rupture sequence with and without body wall defect: Further evidence for separation
Authors: Jamsheer Aleksander , Materna‐Kiryluk Anna , Badura‐Stronka Magdalena , Wiśniewska Katarzyna , Więckowska Barbara , Mejnartowicz Jan , Balcar‐Boroń Anna , Borszewska‐Kornacka Maria , Czerwionka‐Szaflarska Mieczysława , Gajewska Elżbieta , Godula‐Stuglik Urszula , Krawczynski Marian , Limon Janusz , Rusin Józef , Sawulicka‐Oleszczuk Henryka , Szwałkiewicz‐Warowicka Ewa , Świetliński Janusz , Walczak Mieczysław , Latos‐Bieleńska Anna 
Published: January 2009

AbstractBACKGROUND: Amniotic rupture sequence (ARS) is a disruption sequence presenting with fibrous bands, possibly emerging as a result of amniotic tear in the first trimester of gestation. Our comparative study aims to assess whether there is a difference in the clinical pattern of congenital limb and internal organ anomalies between ARS with body wall defect (ARS‐BWD) and ARS without BWD (ARS‐L). METHODS: Among 1,706,639 births recorded between 1998 and 2006, 50 infants with a diagnosis of ARS were reported to the Polish Registry of Congenital Malformations. The information on 3 infants was incomplete, thus only 47 cases were analyzed. These infants were classified into groups of ARS‐L (38 infants) and ARS‐BWD (9 infants). RESULTS: The ARS‐BWD cases were more frequently affected by various congenital defects (overall p < 0.0001), and in particular by urogenital malformations (p = 0.003). In both groups, limb reduction defects occurred in approximately 80% of cases; however, minor and distal limb defects (phalangeal or digital amputation, pseudosyndactyly, constriction rings) predominated in the ARS‐L group (p = 0.0008). The ARS‐L group also had a higher frequency of hand and upper limb involvement. CONCLUSIONS: This observation suggests that amniotic band adhesion in ARS‐L takes place at a later development stage. Although limited by a small sample size, our study contributes to the growing evidence that both ARS entities represent two nosologically distinct conditions. Birth Defects Research (Part A), 2009. © 2009 Wiley‐Liss, Inc.