bluuebunny/crossref_metadata_2025_split huggingface dataset:
Morphology and thermal properties of nylon copolymers containing dimer acid, adipic acid, and hexamethylenediamine
Authors: Wang Xiaohui , Fang Xianli , Yao Cheng , Wu Fucun 
Published: September 2010

AbstractThe effects of the molar ratio of adipic acid to total diacid on the phase morphology and thermal properties of nylon copolymers containing dimer acid, adipic acid, and hexamethylenediamine were investigated. A significant structural transition from the γ form to α and β mixture forms occurred with increasing molar ratio. Meanwhile, the content of the crystals increased markedly. A σ–π* hyper conjugation effect was present in all of the as‐prepared samples. A strong σ–π* hyper conjugation effect could decrease the average distance between interchain amide groups and suppress the scission of the CN bond through the formation of highly combining aza double‐bond CN groups, which would, consequently, make the nylon copolymer much more stable. Differential scanning calorimetry–thermogravimetric analysis results indicate that the low thermal stability of the nylon copolymers with higher molar ratios of adipic acid to total diacid was simply due to the formation of cyclopentanone and caprolactam at 350–420°C, whereas for the nylon copolymers with lower molar ratios, the scission of the CC bond at 430–500°C directed the pyrolysis of the main chain. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Tensile properties of kenaf/unsaturated polyester composites filled with a montmorillonite filler
Authors: Rozman H. D. , Musa L. , Azniwati A. A. , Rozyanty A. R. 
Published: September 2010

AbstractKenaf/unsaturated polyester composites filled with montmorillonite (MMT) filler were produced. Overall, the study showed that, for samples with kenaf filler only, the strength properties decreased as the kenaf filler loading was increased from 40 to 60%. The increase in the kenaf filler loading reduced the amount of matrix material. This subsequently lowered the ability of the sample to absorb energy or distribute stress efficiently. However, with MMT, the tensile properties improved because of the high aspect ratio and surface area of the MMT. The study of the effect of kenaf filler size on the tensile properties showed that the samples with the smallest size (74 μm) displayed the lowest tensile properties compared to the larger ones. This was attributed to the agglomeration of the kenaf fillers. The addition of MMT resulted in an overall increase in the tensile strength of the composites compared to those without MMT. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
In Situsynthesis of inorganic filler‐filled polyethylene using polyethersulfone‐supported TiCl4catalyst system
Authors: Rajesh Smitha , Parikh Parimal A. , Murthy Z. V. P. 
Published: September 2010

AbstractIn situethylene polymerizations with inorganic fillers were performed using catalyst based on titanium tetrachloride supported on polyethersulfone. The inorganic fillers used were MgO, TiO2, and CaCO3, which were pretreated with cocatalyst (methylaluminoxine) for better dispersion onto the polymer matrix. The formation of polyethylene (PE) within the whole matrix was confirmed by Fourier transform infrared studies. The wide‐angle X‐ray diffraction profile of the synthesized PEs indicated the presence of crystalline region. It was found that the nature of inorganic filler did not have any remarkable effect on the melting characteristics of the polymer, but the degree of crystallinity of PE was found to be higher for TiO2‐filled PE. The amount of filler incorporated into the matrix was also evaluated through thermogravimetric analysis, where TiO2‐filled PE showed ∼ 49% of filler material, which was also reflected in the higher productivity obtained by this system. The morphology of the filler‐filled PEs was different, whereas the elemental dispersion was found to be uniform on the surface as elucidated through energy‐dispersive X‐ray spectroscopy. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Effects of MgAlCe‐CO3 layered double hydroxides on the thermal stability of PVC resin
Authors: Yi Shi , Yang Zhan‐Hong , Wang Sheng‐Wei , Liu Dong‐Ren , Wang Su‐Qin , Liu Qing‐Yan , Chi Wei‐Wei 
Published: September 2010

AbstractMgAlCe‐CO3 layered double hydroxides (LDHs) with different Ce/Al molar ratios were prepared by the constant pH coprecipitation method. The synthesized materials were characterized by XRD and FTIR, and the results showed that the hydrotalcite‐like materials have a layered structure. Different LDHs as stabilizers were mixed with PVC resin. The tests of thermal aging and Congo red for the PVC composites were carried out at 180 ± 1°C, respectively. The results showed when MgAlCe‐CO3‐LDHs were added into PVC as single thermal stabilizers, 3 phr (parts per hundred PVC resin) MgAlCe‐CO3‐LDH with Ce/Al (molar ratio) = 0.075 has a better stabilizing effect on PVC than others. Compared with single thermal stabilizers (LDHs or Ca/Zn systems), the composite thermal stabilizers including 0.3 g calcium stearate (Cast2), 1 g zinc stearate (Znst2), and 3 g MgAlCe‐CO3‐LDH have significantly enhanced the thermal stability of PVC sample, and the thermal stable time was over 190 min. The main reason could be concluded to the special structure of Ce element and the synergistic reaction among MgAlCe‐CO3‐LDHs, Cast2, and Znst2. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Modified katira gum for colon targeted drug delivery
Authors: Bharaniraja B. , Jayaram Kumar K. , Prasad C. M. , Sen A. K. 
Published: September 2010

AbstractThe aim of the this study is to develop colon targeted drug delivery systems for Ibuprofen using grafted katira gum as a carrier. Polyacrylamide‐grafted katira gum was synthesized by grafting acrylamide onto katira gum in presence of varying concentration of ceric ammonium nitrate (CAN) as initiator. Elemental analysis, FTIR, TGA, DTA, DSC, and SEM were used to characterize the grafting of acrylamide onto katira gum. Matrix tablets containing various proportions of grafted katira gum were prepared by wet granulation method. All the formulations were evaluated for hardness, drug content, swelling index, and in vitro release studies in simulated gastric fluid, small intestinal fluid, and simulated colonic fluid with and without enzymes. Ibuprofen was used for controlled release study. The drug release mechanism was studied by fitting into Peppas model and was found to be supercase‐II transport. Matrix tablets containing 0.3 g of CAN/gm of acrylamide showed optimum value and retained its physical integrity in simulated gastric, small intestinal and colonic fluid, where as other composition disintegrated within 2 h of dissolution testing in pH 1.2 buffer, simulated gastric fluid. The results of this study indicates that Ibuprofen matrix tablet containing 60 wt % composition of the above grafted katira gum would be potential formulations in delivering the drug to the colon and the more susceptible for enzymatic degradation. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Effect of pressure on the structure and electrical conductivity of cardanol–furfural–polyaniline blends
Authors: Souza Fernando G. , Orlando Marcos T. D. , Michel Ricardo C. , Pinto José Carlos , Cosme Tainá , Oliveira Geiza E. 
Published: September 2010

AbstractPressure‐sensitive polymers that simultaneously present reasonable electrical conducting properties, useful thermosetting behavior, and softness are hard to develop. To combine these properties into a single material, a cardanol‐based phenolic resin was prepared and blended in situ with polyaniline (PAni). The final polymer blend was composed of a soft solid material that could not be dissolved in ordinary solvents. Samples were characterized through X‐ray scattering, Fourier transform infrared (FTIR) spectroscopy, and electrical conductivity and pressure sensitivity measurements. FTIR results indicate that the insertion of PAni into the blends did not change the chemical nature of the resin. According to wide‐angle X‐ray scattering results, PAni was dispersed homogeneously in the final polymer samples; this improved the sensitivity of the electrical conductivity to pressure variations, as confirmed through electromechanical tests. Pressure sensitivity and electromechanical analyses indicated that the produced blends could be used as pressure‐sensing materials. Among the tested materials, the blends containing 5 wt % PAni·H2SO4 presented the largest compression sensitivity values. Finally, it was shown for the first time through XRD analyses under pressure that PAni chains were considerably disturbed by compressive stresses. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Synthesis and characterization of an acrylate‐copolymer‐based antistatic agent composed of a single‐ion conductive polymer electrolyte
Authors: Guo Dongyang , Wang Jiliang , Lei Jingxin 
Published: September 2010

AbstractMonomethoxy poly(ethylene glycol) acrylate (MPEGA) was synthesized through the esterification reaction of acrylic acid and methoxy poly(ethylene glycol)s (MPEGs) of different molecular weights. Then, MPEGA was copolymerized with methyl methacrylate, butyl acrylate, and β‐carboxyethyl acrylate neutralized with potassium hydroxide via conventional solution polymerization. In this way, a single‐ion conductive polymer‐electrolyte‐based antistatic agent (PEAA), in which potassium (K) ions were used as charge carriers, was obtained. The molecular structure, coordination effects between ether oxygen (EO) groups and K cations, ionic conductivity, and crystallization ability of the copolymer were characterized with Fourier transform infrared, conductivity measurements, polarizing optical microscopy, and differential scanning calorimetry, respectively. The crystallinity of the synthesized PEAA apparently decreased with the molecular weight of MPEG and the EO/K molar ratio decreasing, and this led to a corresponding enhancement of the conductivity. The dependence of the conductivity of the copolymer on temperature could be divided into different linear parts, and each was in good agreement with the Arrhenius equation. Moreover, the dependence of the conductivity on the relative humidity (RH) revealed that the PEAA could maintain high ionic conductivity (∼10−6 S/cm) even at the low RH of 10%. This implies the potential widespread application of PEAAs for the preparation of antistatic composites and especially poly(vinyl chloride)‐ and poly(methyl methacrylate)‐related composites because of their considerable miscibility. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Burning‐rate enhancement of a high‐energy rocket composite solid propellant based on ferrocene‐grafted hydroxyl‐terminated polybutadiene binder
Authors: Saravanakumar D. , Sengottuvelan N. , Narayanan V. , Kandaswamy M. , Varghese T. L. 
Published: September 2010

AbstractFour different samples of ferrocene‐grafted hydroxyl‐terminated polybutadiene (Fc‐HTPB), containing 0.20, 0.52, 0.90, and 1.50 wt % iron, were synthesized by the Friedel–Crafts alkylation of ferrocene with hydroxyl‐terminated polybutadiene (HTPB) in the presence of AlCl3 as a (Lewis acid) catalyst. The effects of the reaction conditions on the extent of ferrocene substitution were investigated. The Fc‐HTPBs were characterized by IR, ultraviolet–visible, 1H‐NMR, and 13C‐NMR spectra. The iron content and number of hydroxyl groups were estimated, and the properties, including thermal degradation, viscosity, and propellant burning rates (BRs), were also studied. The thermogravimetric data indicated two major weight loss stages around 395 and 500°C. These two weight losses were due to the depolymerization and decomposition of the cyclized product, respectively, with increasing temperature. The Fc‐HTPB was cured with toluene diisocyanate and isophorone diisocyanate separately with butanediol–trimethylolpropane crosslinker to study their mechanical properties. Better mechanical properties were obtained for the gumstock of Fc‐HTPB polyurethanes with higher NCO/OH ratios. The BRs of the ammonium perchlorate (AP)‐based propellant compositions having these Fc‐HTPBs (without dilution) as a binder were much higher (8.66 mm/s) than those achieved with the HTPB/AP propellant (5.4 mm/s). © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Effect of vegetable‐based polyols in unimodal glass‐transition polyurethane slabstock viscoelastic foams and some guidance for the control of their structure–property behavior. II
Authors: Vaughan Benjamin R. , Wilkes Garth L. , Dounis Dimitrios V. , McLaughlin Cam 
Published: September 2010

AbstractBuilding on the dynamic mechanical analysis (DMA) characterization of the viscoelastic (VE) foam materials discussed in part I of this two‐part sequential series of articles, in this second part, we provide further information on the general physical properties of many of the same soy polyol and castor‐oil VE foams. In particular, the tensile, tear, elongation, indentation force deflection, support factor, compression set, hysteresis and ball‐rebound (resilience), and density properties are addressed in this article. The air flow and force buildup after compression deformation are also considered. Particular attention is also given to noting the degree of correlation of ball‐rebound behavior to that of the DMA damping data provided in part I. We concluded that when all of the properties of these vegetable‐based VE foams were taken as a whole, they had acceptable structure–property behaviors for VE applications, although certainly, the formulations could undoubtedly be further fine‐tuned for additional optimization. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
17β‐Estradiol Exposure Accelerates Skeletal Development in Xenopus laevis Tadpoles
Authors: Bauer‐Dantoin Angela C. , Meinhardt Daniel J. 
Published: September 2010

AbstractAlthough it is well established that estrogen regulates skeletal growth and ossification in mammals, the effects of estrogen on skeletal development in amphibians are relatively uncharacterized. This study was conducted to characterize the impact of 17β‐estradiol exposure on skeletal development in Xenopus laevis tadpoles. On day 48 postfertilization, tadpoles were placed in tanks containing 50% Holtfreter's Solution ±17β‐estradiol at one of four concentrations (10−11, 10−10, 10−9, and 10−8 M). At 7–11 day intervals until day 91, 7–10 tadpoles per group were killed, fixed, measured, and staged. Specimens were then cleared and double‐stained for cartilage and bone, and 34 skeletal elements were analyzed for ossification. Results from the study indicate that both low (10−11 M) and high (10−8 M) concentrations of 17β‐estradiol have a significant stimulatory effect on tadpole development. Both the larval stage and ossification index of tadpoles exposed to 10−11 or 10−8 M 17β‐estradiol were significantly greater than those observed in control animals by day 91 postfertilization. These results are consistent with the hypothesis that endogenous and exogenous estrogen could play a role in the regulation of bone ossification in amphibians. Anat Rec, 2010. © 2010 Wiley‐Liss, Inc.
Morphometric Analysis of Yak Placentomes During Gestation
Authors: Liu Ben , Cui Yan , Yang Bo , Fan Jiangfeng , Zhao Zhiwen , Yu Sijiu 
Published: September 2010

AbstractTo study the morphological characteristics of placentomes during gestation, thirty‐one yaks were used to determine anatomical and histological data of placentomes by morphometric method. The results showed that there were no significant changes in the total number of yak placentomes during gestation, but remarkably fewer placentomes in the non‐pregnant horn compared with the pregnant horn. The mean size of placentomes increased significantly from <61 days to 181–210 days and decreased in 211+ days. The development of placentomes in the pregnant horn were obviously different from that of the non‐pregnant horn except <61 days, which were longer, wider, and thicker. The volume density of fetal villi increased during gestation, with a concomitant reduction in the volume density of caruncular endometrium. However, there was no significant change in the surface density of fetal villi. The volume density of binucleate cell increased in prophase and then decreased. No apparent changes in the volume densities of maternal and fetal pyknotic cell occurred throughout gestation. There was a significant increase in the average total volume of yak placentomes from 61–90 days to 181–210 days and a significant decrease in 211+ days. The same patterns were showed in the average total volumes of caruncular endometrium and binucleate cell as well as the mean total surface area of fetal villi. However, the mean total volumes of fetal villi, maternal and fetal pyknotic cell increased constantly with increasing gestation time. Three types of placentome shape were identified in yak. The results showed that the maternal‐fetal contact area of yak was enlarged by increasing the placentome size as well as the total volume and surface area of placentome component during pregnancy, so placental function could be enhanced further to meet the needs of fetal development. Anat Rec, 2010. © 2010 Wiley‐Liss, Inc.
COX‐2‐Mediated Regulation of VEGF‐C in Association With Lymphangiogenesis and Lymph Node Metastasis in Lung Cancer
Authors: Liu Huidong , Yang Yanmei , Xiao Jianbing , Lv Yanhong , Liu Yan , Yang Huike , Zhao Linghui 
Published: September 2010

AbstractThe mechanisms underlying the effects of COX‐2 on tumor lymphangiogenesis remain largely undefined. Here, the human lung cancer cell lines A549, 95D, Anip973, and AGZY83‐a with different metastatic capacities were investigated by immunostaining, western blotting, and real‐time RT‐PCR. We observed increased expressions of COX‐2 and VEGF‐C in the three highly metastatic cell lines compared with the less metastatic AGZY83‐a cell line. The COX‐2‐specific inhibitor Celecoxib suppressed VEGF‐C expression whereas the main COX‐2 metabolite PGE2 elevated VEGF‐C expression in Anip973 and AGZY83‐a cells in positive and negative experiments. To determine the functional link to COX‐2 more specifically and elucidate the mechanistic pathway, we used a siRNA to knock down the high COX‐2 expression in Anip973 cells and transfected a COX‐2 cDNA to enhance the low COX‐2 expression in AGZY83‐a cells, and then treated the cells with EP1/EP4 agonists or antagonists, respectively. The results revealed that the EP1/EP4 agonists significantly increased VEGF‐C production in the COX‐2‐knockdown Anip973 cells. In contrast, the EP1/EP4 antagonists diminished VEGF‐C production in the COX‐2‐overexpressing AGZY83‐a cells. Furthermore, animal models provided evidence that Celecoxib decreased VEGF‐C expression, lymphangiogenesis, and lymph node metastases in Anip973 cells, whereas PGE2 treatment increased the same factors in the parental AGZY83‐a cells. A positive correlation between COX‐2 and VEGF‐C was also confirmed in vivo. The present data suggest that COX‐2 regulates VEGF‐C expression via the PGE2 pathway, and that EP1/EP4 receptors are involved in PGE2‐mediated VEGF‐C production. Thus, COX‐2 may represent a candidate gene for blocking tumor lymphangiogenesis and lymph node metastasis. Anat Rec, 2010. © 2010 Wiley‐Liss, Inc.
Structural Organization of Hepatic Portal Vein in Rat with Special Reference to Musculature, Intimal Folds, and Endothelial Cell Alignment
Authors: Dong Hong‐Ming , Ichimura Koichiro , Sakai Tatsuo 
Published: September 2010

AbstractStructural organization of hepatic portal vein (HPV) was examined in adult rats by means of light and electron microscopy. Three characteristic features were found in the wall structure of rat HPV. (1) Tunica media consisted of two kinds of smooth muscle. The inner circular smooth muscle (CSM) was composed with one or two layer of smooth muscle cells, and was found in the entire length of the HPV and its tributaries. The outer longitudinal smooth muscle (LSM) was limited to a specific region of HPV; in particular it was well‐developed at distal half of HPV. CSM counteracts luminal hydrostatic pressure to prevent circumferential hyperextension of venous wall, whereas LSM is likely to counteract a tractive force produced by gravity and movement of small intestine. (2) Intima of HPV showed a unique feature, intimal folds, which protruded into the lumen and were aligned almost circumferentially. Intimal folds were found only at the same region where the LSM was well‐developed. Thus, LSM is presumably involved in the formation of intimal folds. (3) The endothelial cells between intimal folds were circumferentially aligned along the folds, although those in the other regions of HPV were arrayed along the longitudinal axis of HPV or the direction of blood flow as reported in other kinds of blood vessel. This finding implied that the circumferential blood flow locally occurs on the surface of intima between the intimal folds. Anat Rec, 2010. © 2010 Wiley‐Liss, Inc.
Epithelial Thickness of the Palatal Mucosa: A Histomorphometric Study in Koreans
Authors: Lee Yong‐Jae , Kwon Young‐Hyuk , Park Joon‐Bong , Herr Yeek , Shin Seung‐Il , Heo Seong‐Joo , Chung Jong‐Hyuk 
Published: September 2010

AbstractSubepithelial connective tissue grafting (SCTG) is a frequently used method in the field of periodontal plastic surgery. There are relatively few reports defining epithelial thickness criteria for palatal mucosal SCTG. The aim of this study was to histologically measure the epithelial thickness of the palatal mucosa in a sample of Korean patients, with the goal of minimizing epithelium‐associated complications after root coverage procedures. A total of 30 Korean patients (12 males and 18 females) were enrolled in this study. To measure epithelial thicknesses, palatal mucosa adjacent to premolars and molars was obtained during procurement of SCTG. The effects of donor site, age and gender on the thickness of the epithelium were assessed and compared by histomorphometric analysis. The mean epithelial thickness of the palatal mucosa in our 30 patients was 430.63 μm, ranging from 113 to 823 μm. Epithelial thickness was not associated with donor site or age, but there were significant differences between genders, with males having much thicker palates than females. Anat Rec, 2010. © 2010 Wiley‐Liss, Inc.
The expression patterns of a eukaryotic initiation factor 3 subunit H in the silk glands in Bombyx mori
Authors: Wang Jia‐Lin , Wang Li‐fu , Wang Jin‐Xing , Zhao Xiao‐Fan 
Published: September 2010

AbstractEukaryotic initiation factor 3 subunit H has been characterized in many organisms, and it has been found to play many roles including help regulate translation initiation. In this work, we studied the tissue distribution and expression profiles of Bombyx mori (B. mori) eIF3 subunit H (BmeIF3h). BmeIF3h was prominently expressed in silk glands, with anterior silk glands (ASGs), middle silk glands (MSGs), and posterior silk glands (PSGs) all expressing BmeIF3h. The expression levels of BmeIF3h in MSGs and PSGs were higher than that in ASGs during 0 d and 2 d of the 5th instar larvae. The expression levels of BmeIF3h in MSGs and PSGs were up‐regulated once the silk glands began to synthesize silk protein during the feeding stage of the 4th instar larvae. Immunohistochemistry showed that BmeIF3h was distributed in the cytoplasm of MSGs cells and in both the nucleus and the cytoplasm of PSGs cells. These data suggest that BmeIF3h had different action behaviors in the MSGs and PSGs related to the production of the silk glue proteins and silk fibre proteins, respectively. © 2010 Wiley Periodicals, Inc.