bluuebunny/crossref_metadata_2025_split huggingface dataset:
The physical properties of carbon nanoparticles dispersed into NBR/LLDPE nanocomposites for corrosion protection applications
Authors: Mahmoud Waleed E. 
Published: September 2011

AbstractIn this study, novel acrylonitrile butadiene rubber (NBR) nanocomposites with improved electrical conductivity and mechanical properties were synthesized. Carbon nanoparticles (CNP)/NBR composites and CNP‐polyethylene/NBR nanocomposites were prepared by mixing via two‐roll mill. The first type of the nanocomposite was produced to determine the percolation threshold concentration (Vc). The second type with constant CNP concentration, slightly over Vc (0.2 vol %), was synthesized to investigate the influence of polyethylene content on the mechanical, electrical and swelling behavior of nanocomposites. Only the nanocomposites with 3 vol % polyethylene loading showed electrical conductivity. However, the composites with higher polyethylene loadings showed insulating behavior due to hindrance of CNP network by polyethylene layers. Swelling measurements revealed that the change in entropy of the swelling increased with the increase in disorder level but decreased with the increase in intercalation level of CNP in the disordered intercalated nanocomposite. The increase in solvent uptake was comparable with the free volume in NBR matrix upon inclusion of nanoparticles, whereas the inhibition in solvent uptake for higher polyethylene loading was described by bridging flocculation. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
A comparative study of two polyelectrolyte complexes
Authors: Valdés Oscar , Alexandrova Larissa , Katime Issa , Zaldívar Dionisio 
Published: September 2011

AbstractInterpenetrating polymeric networks (IPNs) based on natural sodium alginate (NaAlg) biopolymer matrix and synthetic hydrophilic polymer were synthesized using sequential method. Poly(acryloxyethyl‐trimethylammonium chloride‐co‐2‐hydroxyethyl methacrylate) (poly(Q‐co‐H)) with high content of quaternary ammonium groups (Q units) was used as a synthetic polymer for the purpose. Since NaAlg has anionic nature and poly(Q‐co‐H) is a polycation polyelectrolyte complex (PEC) was also prepared via ion interaction between these natural and synthetic components by mixing their water solutions. The all prepared materials were characterized by thermogravimetric analysis (TGA) and Fourier transform infrared spectroscopy (ATR‐FTIR). The comparative analysis of IPNs of different compositions was carried out. Behavior of IPNs was also compared to PEC, material obtained via simple ionic interaction between oppositely charged polymers. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Sound absorption properties of polyurethane/nano‐silica nanocomposite foams
Authors: Lee Joonmo , Kim Gue‐Hyun , Ha Chang‐Sik 
Published: September 2011

AbstractIn this study, polyurethane (PU)/nano‐silica nancomposite foams were prepared. The effects of isocyanate index, cell size, density, and molecular weight of polyols on the sound absorption ratio of PU/nano‐silica foams were investigated. With increasing nano‐silica content, the sound absorption ratio of PU/nano‐silica foams increases over the entire frequency range investigated in this study. Decrease of isocyanate index, cell size, and increase of density leads to the increase of sound absorption ratio of PU/nano‐silica foams. PU/nano‐silica foams have a broad Tg centered around room temperature by decreasing molecular weight of polyol resulting in good sound absorbing ability. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Toughening effect of comonomer on acrylic denture base resin prepared via suspension copolymerization
Authors: Zheng Junping , Wang Lei , Hu Yumei , Yao Kangde 
Published: September 2011

AbstractIn this article, three copolymers used as denture base resins were prepared via suspension copolymerization using butyl acrylate (BA), butyl methacrylate (BMA), or methyl acrylate (MA) with methyl methacrylate (MMA), respectively. The homopolymers and copolymers were characterized by 13C nuclear magnetic resonance (13C NMR). The influence of the three comonomers on the mechanical property was investigated in details and the fracture surfaces of copolymer specimens were examined using scanning electron microscopy (SEM). Meanwhile, the Tg values of three copolymers were examined by differential scanning calorimetry (DSC). The results indicate that, poly(methyl methacrylate) (PMMA) copolymers with BA, BMA, or MA have been successfully prepared via suspension copolymerization. The presence of BA, BMA, or MA could improve the mechanical property especially the impact strength, the toughness of the materials was remarkably improved. The toughening effect of BMA monomer is most significant. When the content of BA is 2 wt %, the flexural strength improves by 51% and the impact strength improves by 81.3%. The Tg values of three copolymers all decrease. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Polyurethane foams derived from liquefied mountain pine beetle‐infested barks
Authors: Zhao Yong , Yan Ning , Feng Martin 
Published: September 2011

AbstractIn this study, lodgepole pine (Pinus contorta Dougl.) bark infested by the mountain pine beetles (Dendroctonus ponderosae hopkins) was liquefied using either polyethylene glycol (PEG) or polyethylene glycol/glycerol (PEG/G) as the solvent. It was found that the addition of glycerol to PEG reduced the residue ratio during bark liquefaction. The liquefied bark fraction obtained by using PEG/G had a slightly higher hydroxyl number than that obtained by using PEG. The residue from PEG/G liquefaction contained less lignin and more cellulose than the residue from PEG liquefaction. Various polyurethane foams containing liquefied bark fractions were made, and it was found that the weight ratios of liquefied bark to pMDI used in foam formulation and bark liquefaction solvents affected the density, gel content, thermal stability, mechanical properties, and the cell structure of the resulting foams. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Novel surface modifying macromolecules (SMMs) blended polysulfone gas separation membranes by phase inversion technique
Authors: Savoji Houman , Rana Dipak , Matsuura Takeshi , Soltanieh Mohammad , Tabe Shahram 
Published: September 2011

AbstractIn this article an attempt was made to fabricate defect‐free asymmetric polysulfone (PSf) membranes for the separation of oxygen and nitrogen. The approach is based on the enhanced delayed demixing by blending surface modifying macromolecules (SMMs) in the casting solution and by immersing the cast film in isopropanol for a certain period before it is immersed in water. Different SMMs, including hydrophobic and charged SMMs, were synthesized, characterized, and blended to the host PSf. It was found that the charged SMM could indeed contribute to the removal of defective pores from the skin layer and enhancement of oxygen/nitrogen selectivity. The experimental results were further interpreted based on the shift of the phase boundary line on the polymer/solvent/nonsolvent triangular diagram, which occurred when SMMs were blended to PSf, due to the change in the polymer/nonsolvent interaction. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Synthesis of Novel Thiazolyl‐Pyrimidines and Their Anticancer Activity in Vitro
Authors: Shi Hai‐Bo , Li Hai‐Bo , Lu Kong‐Qin , Zhu Xia‐Re , Hu Wei‐Xiao , Pei Wen 
Published: September 2011

AbstractA series of novel compounds 7–43 were prepared via the condensation of enaminones 4a–h and the guanidines carbonate 6a–f. The structures of these newly synthesized compounds were confirmed by 1H‐NMR, MS, EA and IR. All the compounds were tested for their cytotoxic activity in vitro against human cancer cell lines including Ishikawa, A549, BEL‐7404, SPC‐A‐01 and SGC‐7901. Most of them showed moderate cytotoxic against the tested cell lines. Among them, the most potent compounds 9 and 30 exhibited more efficient activity against Ishikawa, A549.
The Application of Tandem Aza‐Wittig Reaction to Synthesize Artemisinin–Guanidine Hybrids and Their Anti‐Tumor Activity
Authors: Xie Lijun , Zhao Yanfang , Zhai Xin , Li Peng , Liu Chun , Li Yangxiong , Gong Ping 
Published: September 2011

AbstractThree series of novel artemisinin–guanidine hybrids 4a–4f, 8a–8h and 9a–9h have been facilely synthesized via four‐component reaction (aza‐Wittig reaction) and evaluated for their anti‐tumor activities against A549, HT‐29 and MDA‐MB‐231 cell lines in vitro. All of the tested compounds showed enhanced anti‐tumor activities with IC50 values ranging from 0.02 µM to 12.0 µM as compared to DHA (dihydroartemisinin). Among them, artemisinin derived dimers, compounds 9b (IC50 = 0.05 µM), 9d (IC50 = 0.06 µM) and 9f (IC50 = 0.02 µM) were found to be most active against HT29 cells.
Dimethylarginine dimethylaminohydrolase 2, a newly identified mitochondrial protein modulating nitric oxide synthesis in normal human chondrocytes
Authors: Cillero‐Pastor Berta , Mateos Jesús , Fernández‐López Carlos , Oreiro Natividad , Ruiz‐Romero Cristina , Blanco Francisco J. 
Published: September 2011

AbstractObjectiveThe mitochondrion is known to be important to chondrocyte survival. This study was undertaken to analyze protein expression profiles in chondrocyte mitochondria that are affected by interleukin‐1β (IL‐1β).MethodsNormal human chondrocytes were isolated from knee cartilage obtained at autopsy from subjects with no history of joint disease. Cells were incubated for 48 hours with or without IL‐1β (5 ng/ml). Proteins were separated by 2‐dimensional electrophoresis and stained with Sypro Ruby, Coomassie brilliant blue, or silver. Qualitative and quantitative analyses were carried out using PDQuest software. Proteins were identified by mass spectrometry using matrix‐assisted laser desorption ionization–time‐of‐flight/time‐of‐flight technology. The proteomic results were validated by real‐time polymerase chain reaction, Western blotting, and microscopy. Nitric oxide (NO) was quantified using Griess reagent.ResultsComparative analysis revealed differential expression of signal transduction proteins that regulate cytoskeleton, transcription, metabolic, and stress‐related pathways. In total extracts, dimethylarginine dimethylaminohydrolase 2 (DDAH‐2) did not show any change in expression after stimulation with IL‐1β. However, in mitochondrial extracts, DDAH‐2 expression was significantly increased after exposure to IL‐1β. Conventional immunofluorescence and confocal microscopy revealed the presence of DDAH‐2 in the mitochondria of IL‐1β–stimulated chondrocytes. These results were reproducible in cartilage explants treated with IL‐1β. In addition, we demonstrated that inhibition of the expression of DDAH‐2, as well as interruption of its translocation to the mitochondria, reduced the NO production induced by IL‐1β. DDAH‐2 protein expression was higher in osteoarthritic (OA) cartilage than in normal cartilage.ConclusionIn the present study, the presence of DDAH‐2 in normal human chondrocytes and cartilage was identified for the first time. DDAH‐2 could play an important role in IL‐1β–induced NO production and in OA pathogenesis.
Macrophage positron emission tomography imaging as a biomarker for preclinical rheumatoid arthritis: Findings of a prospective pilot study
Authors: Gent Yoony Y. J. , Voskuyl Alexandre E. , Kloet Reina W. , van Schaardenburg Dirkjan , Hoekstra Otto S. , Dijkmans Ben A. C. , Lammertsma Adriaan A. , van der Laken Conny J. 
Published: September 2011

AbstractObjectiveTo conduct a prospective pilot study to determine whether macrophage targeting by 11C‐(R)‐PK11195 positron emission tomography (PET) can visualize subclinical synovitis in arthralgia patients who have anti–citrullinated protein antibodies (ACPAs).MethodsTwenty‐nine arthralgia patients who were positive for ACPAs but did not have clinical arthritis were studied. High (spatial)–resolution 11C‐(R)‐PK11195 PET scans of the hands and wrists were performed. For all metacarpophalangeal, proximal interphalangeal, and wrist joints (i.e., 22 joints per patient), tracer uptake was scored semiquantitatively (0–3 scale) by 2 observers who were blinded with regard to the clinical data. Patients were followed up prospectively for 24 months to investigate the development of clinical arthritis.ResultsOverall agreement and kappa values for the readings of the 2 observers were, respectively, 97% and 0.91 (95% confidence interval [95% CI] 0.74–1) at the patient level and 99% and 0.81 (95% CI 0.65–0.96) at the joint level. In 4 patients, at least 1 and as many as 5 PET‐positive joints (score ≥1) were found at baseline. Within 2 years of followup, 9 patients had developed clinical arthritis. This included all 4 patients with positive findings on the 11C‐(R)‐PK11195 scan, who developed clinical arthritis in the hand/wrist region, as identified on PET scans. Of the 5 remaining arthritis patients with negative findings on PET scans, 2 developed arthritis in the hand joints and 3 developed arthritis at locations outside the field of view of the PET scanner.ConclusionSubclinical arthritis in ACPA‐positive arthralgia patients could be visualized by 11C‐(R)‐PK11195 PET scanning and was associated with development of arthritis within 2 years of followup. This indicates that 11C‐(R)‐PK11195 PET may be useful in determining arthritis activity in the preclinical phase of RA.
Browsing software of the Visible Korean data used for teaching sectional anatomy
Authors: Shin Dong Sun , Chung Min Suk , Park Hyo Seok , Park Jin Seo , Hwang Sung Bae 
Published: September 2011

AbstractThe interpretation of computed tomographs (CTs) and magnetic resonance images (MRIs) to diagnose clinical conditions requires basic knowledge of sectional anatomy. Sectional anatomy has traditionally been taught using sectioned cadavers, atlases, and/or computer software. The computer software commonly used for this subject is practical and efficient for students but could be more advanced. The objective of this research was to present browsing software developed from the Visible Korean images that can be used for teaching sectional anatomy. One thousand seven hundred and two sets of MRIs, CTs, and sectioned images (intervals, one millimeter) of a whole male cadaver were prepared. Over 900 structures in the sectioned images were outlined and then filled with different colors to elaborate each structure. Software was developed where four corresponding images could be displayed simultaneously; in addition, the structures in the image data could be readily recognized with the aid of the color‐filled outlines. The software, distributed free of charge, could be a valuable tool to teach medical students. For example, sectional anatomy could be taught by showing the sectioned images with real color and high resolution. Students could then review the lecture by using the sectioned and color‐filled images on their own computers. Students could also be evaluated using the same software. Furthermore, other investigators would be able to replace the images for more comprehensive sectional anatomy. Anat Sci Educ. © 2011 American Association of Anatomists.
Ligand‐Assisted, Copper(II) Acetate‐Accelerated Azide–Alkyne Cycloaddition
Authors: Michaels Heather A. , Zhu Lei 
Published: September 2011

AbstractPolytriazole ligands such as the widely used tris[(1‐benzyl‐1 H‐1,2,3‐triazol‐4‐yl)methyl]amine (TBTA), are shown to assist copper(II) acetate‐mediated azide–alkyne cycloaddition (AAC) reactions that involve nonchelating azides. Tris(2‐{4‐[(dimethylamino)methyl]‐1 H‐1,2,3‐traizol‐1‐yl}ethyl)amine (DTEA) outperforms TBTA in a number of reactions. The satisfactory solubility of DTEA in a wide range of polar and nonpolar solvents, including water and toluene, renders it advantageous under copper(II) acetate‐mediated conditions. The copper(II) acetate‐mediated formation of the three triazolyl groups in a tris(triazolyl)‐based ligand occurs sequentially with an inhibitory effect in the last step. The kinetic investigations of the ligand‐assisted reactions reveal an interesting mechanistic dependence on the relative affinity of azide and alkyne to copper (II). In addition to expanding the scope of the copper(II) acetate‐mediated AAC reactions to include nonchelating azides, this work offers evidence for the mechanistic synergy between the title reaction and the alkyne oxidative homocoupling reaction. The elucidation of the structural details of the polytriazole‐ligand‐bound reactive species in copper(I/II)‐mediated AAC reactions, however, awaits further characterization of the metal coordination chemistry of polytriazole ligands.
Global maximum principle for the forward–backward stochastic optimal control problem with poisson jumps
Authors: Shi Jingtao 
Published: September 2011

AbstractThis paper is concerned with the forward–backward stochastic optimal control problem with Poisson jumps. A necessary condition of optimality in the form of a global maximum principle as well as a sufficient condition of optimality are presented under the assumption that the diffusion and jump coefficients do not contain the control variable, and the control domain need not be convex. The case where there are some state constraints is also discussed. A financial example is discussed to illustrate the application of our result.Copyright © 2011 John Wiley and Sons Asia Pte Ltd and Chinese Automatic Control Society
Consensus of data‐sampled multi‐agent systems with Markovian switching topologies
Authors: Zhao Huanyu , Xu Shengyuan , Yuan Deming 
Published: September 2011

AbstractThis paper studies the consensus problem of data‐sampled multi‐agent systems with Markovian switching topologies. Two different consensus algorithms are considered. By a system transformation, the mean‐square consensus problem of multi‐agent systems is converted into the mean‐square stability problem of Markov jump systems. Necessary and sufficient conditions of mean‐square consensus are obtained. The cone complementary linearization algorithm is used to get the allowable control gain. Simulation examples are given to show the effectiveness of the results.Copyright © 2011 John Wiley and Sons Asia Pte Ltd and Chinese Automatic Control Society
Factor analysis of the Parenting Stress Index‐Short Form with parents of young children with autism spectrum disorders
Authors: Zaidman‐Zait Anat , Mirenda Pat , Zumbo Bruno D. , Georgiades Stelios , Szatmari Peter , Bryson Susan , Fombonne Eric , Roberts Wendy , Smith Isabel , Vaillancourt Tracy , Volden Joanne , Waddell Charlotte , Zwaigenbaum Lonnie , Duku Eric , Thompson Ann ,   the Pathways in ASD Study Team
Published: September 2011

AbstractThe primary purpose of this study was to examine the underlying factor structure of the Parenting Stress Index‐Short Form (PSI‐SF) in a large cohort of parents of young children with autism spectrum disorder (ASD). A secondary goal was to examine relationships between PSI‐SF factors and autism severity, child behavior problems, and parental mental health variables that have been shown to be related to parental stress in previous research. A confirmatory factor analysis (CFA) was used to examine the three‐factor structure described in the PSI‐SF manual [Abidin, 1995]: parental distress, parent–child dysfunctional interaction, and difficult child. Results of the CFA indicated that the three‐factor structure was unacceptable when applied to the study sample. Thus, an exploratory factor analysis was conducted and suggested a six‐factor model as the best alternative for the PSI‐SF index. Spearman's correlations revealed significant positive correlations with moderate to large effect sizes between the revised PSI‐SF factors and autism severity, externalizing and internalizing child behaviors, and an index of parent mental health. The revised factors represent more narrowly defined aspects of the three original subscales of the PSI‐SF and might prove to be advantageous in both research and clinical applications. Autism Res 2011,4:336–346. © 2011 International Society for Autism Research, Wiley Periodicals, Inc.
What is the impact of autism on mother–child interactions within families with a child with autism spectrum disorder?
Authors: Meirsschaut Mieke , Warreyn Petra , Roeyers Herbert 
Published: September 2011

AbstractThis within‐family study investigated whether mothers differentiate between children in their interactive behavior. Mothers were observed during a play and a task interaction separately with their child with autism spectrum disorder (ASD) (between 46 and 84 months old, M = 68) and with a younger sibling (between 29 and 67 months old, M = 48). Additionally, the social behavior of the children with ASD and their non‐ASD siblings was compared. Results show that mothers differentiated in their responsiveness but not in their initiatives toward the children. Children with ASD and their non‐ASD siblings were equally responsive but children with ASD were more imperative toward their caregiver. Several interpretations of these findings are discussed. Finally, it is concluded that family‐based interventions will benefit from a better understanding of the effect of ASD on mother–child interactions within families with a child with ASD. Therefore, between‐family studies should be complemented with within‐family studies. Autism Res 2011,4:358–367. © 2011 International Society for Autism Research, Wiley Periodicals, Inc.
Outcomes following surgery for colorectal cancer with synchronous peritoneal metastases
Authors: Mulsow J , Merkel S , Agaimy A , Hohenberger W 
Published: September 2011

Abstract

Background
The optimal treatment of peritoneal carcinomatosis of colorectal origin appears to be a combination of systemic chemotherapy and complete surgical cytoreduction with synchronous intraperitoneal chemotherapy. The aim of this study was to assess the feasibility of, and outcomes following, surgical treatment and systemic chemotherapy alone.

Methods
Prospectively collated data from the Erlangen Registry for Colorectal Cancer were analysed for patients presenting with peritoneal carcinomatosis of colorectal origin between 1990 and 2006. Operative and adjuvant treatment, along with details of postoperative morbidity, were evaluated and correlated with survival outcomes after 5 years.

Results
Some 125 patients underwent surgical resection for colorectal cancer and synchronous peritoneal carcinomatosis. Two-thirds also had non-peritoneal distant metastases. R0/R1 resection was possible in 24 (59 per cent) of 41 patients with peritoneal metastases alone, and in a further seven patients with both peritoneal and distant metastases (overall R0/R1 resection rate 24·8 per cent). In-hospital morbidity and mortality rates were 32·0 and 12·0 per cent respectively. Twenty-three of the 31 patients who underwent R0/R1 resection developed recurrent disease. Median survival for the entire group was 12 months. Following R0/R1 resection median survival was 25 months and the 5-year survival rate 22 per cent. Six (4·8 per cent) of the 125 patients survived for more than 5 years.

Conclusion
Complete resection of all metastatic disease was associated with improved survival and was possible in almost 60 per cent of patients with peritoneal metastases alone.