bluuebunny/crossref_metadata_2025 huggingface dataset:
Detection of Nucleophosmin 1 Mutations by Quantitative Real-Time Polymerase Chain Reaction Versus Capillary Electrophoresis: A Comparative Study
Authors: Barakat Fareed H , Luthra Rajyalakshmi , Yin C. Cameron , Barkoh Bedia A , Hai Seema , Jamil Waqar , Bhakta Yaminiben I , Chen Su , Medeiros L. Jeffrey , Zuo Zhuang
Published: September 2011

Context.—Nucleophosmin 1 (NPM1) is the most commonly mutated gene in acute myeloid leukemia. Detection of NPM1 mutations is useful for stratifying patients for therapy, predicting prognosis, and assessing for minimal residual disease. Several methods have been developed to rapidly detect NPM1 mutations in genomic DNA and/or messenger RNA specimens.

Objective.—To directly compare a quantitative real-time polymerase chain reaction (qPCR) assay with a widely used capillary electrophoresis assay for detecting NPM1 mutations.

Design.—We adopted and modified a qPCR assay designed to detect the 6 most common NPM1 mutations and performed the assay in parallel with capillary electrophoresis assay in 207 bone marrow aspirate or peripheral blood samples from patients with a range of hematolymphoid neoplasms.

Results.—The qPCR assay demonstrated a higher analytical sensitivity than the capillary electrophoresis 1/1000 versus 1/40, respectively. The capillary electrophoresis assay generated 10 equivocal results that needed to be repeated, whereas the qPCR assay generated only 1 equivocal result. After test conditions were optimized, the qPCR and capillary electrophoresis methods produced 100% concordant results, 85 positive and 122 negative.

Conclusions.—Given the higher analytical sensitivity and specificity of the qPCR assay, that assay is less likely to generate equivocal results than the capillary electrophoresis assay. Moreover, the qPCR assay is quantitative, faster, cheaper, less prone to contamination, and well suited for monitoring minimal residual disease.
Embryonal Central Nervous System Neoplasms Arising in Infants and Young Children: A Pediatric Brain Tumor Consortium Study
Authors: McLendon Roger E , Adekunle Adesina , Rajaram Veena , Koçak Mehmet , Blaney Susan M
Published: September 2011

Context.—Medulloblastomas (MBs) and atypical teratoid/rhabdoid tumors (AT/RTs) arising in infants and children can be difficult to distinguish; however, histologic characterization is prognostically important.

Objective.—To determine histologic and phenotypic markers associated with utility with progression-free survival (PFS) and overall survival (OS) in children younger than 3 years with MBs and AT/RTs.

Design.—We undertook a histologic and immunophenotypic study of MBs and AT/RTs arising in infants and children younger than 3 years treated in a Pediatric Brain Tumor Consortium study. The 41 girls and 55 boys ranged in age from 2 to 36 months at enrollment. These infants and children exhibited 51 MBs, 26 AT/RTs, and 24 other tumors (not further studied). Median follow-up of the patients was 17.2 months from diagnosis (range: 1.4–93 months).

Results.—Infants and children with AT/RT exhibited a statistically significant shorter PFS and OS when compared to infants and children with MBs (both P < .001). A lack of nuclear BAF47 immunohistochemical reactivity proved reliable in identifying AT/RTs. Among MBs, our data suggest an association of nodularity and prolonged PFS and OS, which must be independently confirmed. Anaplasia correlated with OTX2 reactivity and both OTX2 and moderate to severe anaplasia correlated with PFS but not with OS.

Conclusion.—Distinguishing AT/RT from MBs is clinically important. For expert neuropathologists, the diagnoses of AT/RT and MB can be reliably made from hematoxylin-eosin stains in the vast majority of cases. However certain rare small cell variants of AT/RT can be confused with MB. We also found that immunohistochemical reactivity for BAF47 is clinically useful in distinguishing MBs from AT/RTs and for identifying certain small cell AT/RTs. Among MBs, nodularity may be an important prognostic factor for improved PFS and OS in infants and children.
Angiocentric Glioma: A Clinicopathologic Review of 5 Tumors With Identification of Associated Cortical Dysplasia
Authors: Marburger Trent , Prayson Richard
Published: September 2011

Context.—Angiocentric glioma is a rare, epilepsy-associated, low-grade neoplasm with a characteristic perivascular growth pattern.

Objective.—To describe the clinicopathologic features of 5 angiocentric gliomas and to evaluate for coexistent malformation of cortical development/cortical dysplasia.

Design.—Retrospective review of the clinicopathologic features of 5 angiocentric gliomas (3 males and 2 females; median age at surgery, 10 years; range, 3–19 years).

Results.—Seizures were the most common presenting symptom (n  =  4); 1 patient presented with headaches. Four of the tumors were located in the parieto-occipital, parietal, or temporal cortex and 1 case arose in the thalamus. All tumors consisted of an angiocentric growth pattern of bipolar spindle cells with mild pleomorphism. Three tumors also demonstrated a focal solid growth pattern. Evidence of adjacent malformation of cortical development/focal cortical dysplasia was observed in 4 of 4 cases with sufficient tissue for evaluation; all were Palmini et al type I lesions (type IA, n  =  1; type IB, n  =  3). All patients were alive at last known follow-up (17–131 months).

Conclusions.—The thalamic location of 1 tumor represents an undescribed location for this typically superficial cortical tumor. A subset of angiocentric gliomas, similar to other low-grade chronic epilepsy-related tumors of childhood, are associated with coexistent malformation of cortical development, suggesting a developmental basis to their origin.
Everyday Attention: Variation in Mind Wandering and Memory in a Lecture
Authors: Risko Evan F. , Anderson Nicola , Sarwal Amara , Engelhardt Megan , Kingstone Alan
Published: September 2011

Understanding the factors underlying variation in attentional state is critical in a number of domains. Here, we investigate the relation between time on task and mind wandering (i.e., a state of decoupled attention) in the context of a lecture. Lectures are the primary means of knowledge transmission in post secondary education rendering an understanding of attentional variations in lectures a pressing practical concern. We report two experiments wherein participants watched a video recorded lecture either alone (Experiment 1) or in a classroom context (Experiment 2). Participants responded to mind wandering probes at various times in the lecture in an effort to track variations in mind wandering over time. In addition, following the lecture, memory for the lecture material was tested. Results demonstrate that in a lecture mind wandering increases with time on task and memory for the lecture material decreases. In addition, there was a significant relation between mind wandering and memory for lecture material. Theoretical and practical applications of the present results are discussed. Copyright © 2011 John Wiley & Sons, Ltd.
Illness perceptions in patients with gout and the relationship with progression of musculoskeletal disability
Authors: Dalbeth Nicola , Petrie Keith J. , House Meaghan , Chong Jimmy , Leung Wingchi , Chegudi Rini , Horne Anne , Gamble Greg , McQueen Fiona M. , Taylor William J.
Published: September 2011

Objective

Illness perceptions are key determinants of behavior directed at managing disease. Although suboptimal disease management has been reported in patients with gout, patients' perceptions of illness have not been systematically studied. The aim of this study was to examine illness perceptions in patients with gout.

Methods

A total of 142 patients with gout for <10 years were recruited from primary and secondary care settings. Participants completed a gout‐specific Brief Illness Perception Questionnaire, questionnaires about medication beliefs and adherence to urate‐lowering therapy (ULT), and had a comprehensive assessment of gout disease activity. Serum urate, flare frequency, and Health Assessment Questionnaire (HAQ‐II) scores were recorded at baseline and after 1 year.

Results

Patients viewed gout as a chronic condition that was responsive to treatment but not strongly influenced by personal actions. Overall, gout was seen as having a moderate impact on their life. Most patients believed that gout was caused by dietary factors. Adherence to ULT was positively associated with a greater perceived understanding of gout and inversely associated with perceived severity and consequences of disease. Of the clinical factors assessed, pain scores were most strongly associated with negative illness perception scores at baseline. Baseline illness perception scores (perceived severity of symptoms and consequences, lower personal and treatment control) predicted worsening musculoskeletal disability at 1 year as determined by the HAQ‐II. This relationship was independent of baseline disability scores.

Conclusion

Negative or pessimistic views about gout are associated with poorly controlled disease, lower adherence to ULT, and progression of musculoskeletal disability in patients with gout.
Secular trend of adhesive capsulitis
Authors: White D. , Choi H. , Peloquin C. , Zhu Y. , Zhang Y.
Published: September 2011

Objective

Adhesive capsulitis (AC) is a painful shoulder disorder resulting in restrictions of daily activities. Given the recent increase in risk factors for AC, such as diabetes mellitus, research is needed to examine if the incidence of AC has also increased. Therefore, the purpose of this study was to describe the secular trend of AC.

Methods

Subjects were from The Health Improvement Network, an electronic medical record database of general practices across the UK from 1995–2008. General practitioners diagnosed AC. We included subjects ages 40–79 years and defined an incident case as the first diagnosis of AC following at least 1 year of enrollment in the database. We examined the potential independent effects of age, calendar time, and birth cohort using an age–period–cohort model. To approximate effect estimates, we applied proportional hazards models and separately adjusted for diabetes mellitus.

Results

Of 2,188,958 subjects (50.0% women), the incidence of AC was 2.36 and 3.38 per 1,000 person‐years for men and women, respectively. Age–period–cohort model graphs suggested a secular trend due to a birth cohort, but not calendar effect. For each 10‐year increment in birth cohort, the incidence rate increased by 8% in women (hazard ratio 1.08, 95% confidence interval 1.05–1.13). There was no increase in AC incidence for men. Adjusting for diabetes mellitus did not change these associations materially.

Conclusion

We found women born more recently are at a higher risk of developing AC compared with women born earlier. Future research is needed to identify risk factors that may be responsible for this increase.
Effectiveness of dexamethasone iontophoresis for temporomandibular joint involvement in juvenile idiopathic arthritis
Authors: Mina Rina , Melson Paula , Powell Stephanie , Rao Marepalli , Hinze Claas , Passo Murray , Graham T. Brent , Brunner Hermine I.
Published: September 2011

Objective

Temporomandibular joint (TMJ) involvement is common in juvenile idiopathic arthritis (JIA). Dexamethasone iontophoresis (DIP) uses low‐grade electric currents for transdermal dexamethasone delivery into deeper anatomic structures. The purpose of this study was to assess the safety and effectiveness of DIP for the treatment of TMJ involvement in JIA, and to delineate variables that are associated with improvement after DIP.

Methods

Medical records of all JIA patients who underwent DIP for TMJ involvement at a larger tertiary pediatric rheumatology center from 1997–2011 were reviewed. DIP was performed using a standard protocol. The effectiveness of DIP was assessed by comparing the maximal interincisor opening (MIOTMJ) and the maximal lateral excursion (MLETMJ) before and after treatment.

Results

Twenty‐eight patients (ages 2–21 years) who received an average of 8 DIP treatment sessions per involved TMJ were included in the analysis. Statistically significant improvement in the median MIOTMJ (P < 0.0001) was observed in 68%. The median MLETMJ (P = 0.03) improved in 69%, and resolution of TMJ pain occurred in 73% of the patients who had TMJ pain at baseline. Side effects of DIP were transient site erythema (86%), skin blister (4%), and metallic taste (4%). Improvement in TMJ range of motion from DIP is associated with lower MIOTMJ, lower MLETMJ, and absence of TMJ crepitus at baseline.

Conclusion

In this pilot study, DIP appeared to be an effective and safe initial treatment of TMJ involvement in JIA, especially among patients with decreased TMJ measurements. Prospective controlled studies are needed.
Microstructure and Properties of Spark Plasma Sintered Carbon Nanotube Reinforced Aluminum Matrix Composites
Authors: Yadav Vineet , Harimkar Sandip P.
Published: September 2011

In this paper, spark plasma sintering (SPS) of multi‐walled carbon nanotube (CNT) reinforced aluminum matrix composites is reported. Ball milling of the Al‐CNT mixture with polyacrylic acid (PAA) dispersion agent followed by SPS resulted in uniform dispersion of CNTs in dense composite compacts. Significant improvement in microhardness, nanohardness, and compressive yield strength was observed with 2 wt% CNT reinforcement in aluminum matrix composites. The Al‐CNT composites further exhibited improved wear resistance and lower friction coefficient due to strengthening and self‐lubricating effects of CNTs.
Ti–6Al–4V–0.5B—A Modified Alloy for Implants Produced by Metal Injection Molding
Authors: Ebel Thomas , Blawert Carsten , Willumeit Regine , Luthringer Bérengère J. C. , Ferri Orley Milagres , Feyerabend Frank
Published: September 2011

Permanent implants have to fulfill a great variety of requirements related to both material and geometry. In addition, manufacturing costs play a role, which is getting steadily more and more important. Metal Injection Molding (MIM) of titanium alloy powders may contribute to the development of implants with higher functionality without increasing the price. High degree of freedom with regard to geometry, high material efficiency, and the possibility to create even porous structures are main benefits from applying this technique. Today, even long‐term implants made from Ti–6Al–4V by MIM are commercially available. However, in order to improve fatigue behavior it is beneficial to perform a minor variation of Ti–6Al–4V by adding a low amount of boron. In this paper the mechanical, biological, and corrosion properties of specimens manufactured from Ti–6Al–4V–0.5B alloy by MIM are presented. In order to exclude unknown reactions in the body environment due to the boron content, corrosion, and biological tests are performed. Tensile and fatigue tests characterize the mechanical properties. Potentiodynamic polarization and electrochemical impedance spectroscopy are done in comparison to wrought and to MIM processed Ti–6Al–4V material. For cell experiments cancellous bone cells are cultured to perform adhesion, proliferation, and viability experiments. The results presented here show that the alloy Ti–6Al–4V–0.5B satisfies all basic needs of a material for highly loaded permanent implants manufactured by MIM.
Simultaneous Electrical and Thermoelectric Parameter Retrieval via Two Terminal Current–Voltage Measurements on Individual ZnO Nanowires
Authors: Liu Yang , Zhang Zhiyong , Wei Xianlong , Li Quan , Peng Lian‐Mao
Published: September 2011

The thermoelectric parameters, in particular the thermal conductivity and dimensionless figure of merit ZT, of ZnO nanowires, are estimated via two terminal current–voltage measurements. The measurements are carried out in situ in a transmission electron microscope and negative differential conductance is observed on individually suspended ZnO nanowires. From the low bias region of the current–voltage curve, the electrical parameters, including carrier concentration and mobility, are obtained by fitting the experimental data using a metal–semiconductor–metal model. The thermal conductivity is extracted from the high bias region of the same current–voltage curve using a self‐consistent method, which combines the self‐heating thermal conduction and electrical transport properties of ZnO nanowires. It is shown that the thermal conductivity of ZnO nanowires is suppressed significantly in comparison with that of bulk ZnO, which is attributed to the strong surface scattering of phonons. The thermal conductivity is also found to decrease more steeply than the expected $ {1 \mathord{\left/{\vphantom {1 T}} \right.} T} $ trend, but does obey a $ {1 \mathord{\left/{\vphantom {1 {\left({\alpha T + \beta T^2} \right)}}} \right. } {\left({\alpha T + \beta T^2} \right)}} $ relation; this is shown to result from four‐phonon processes at high temperatures. The dimensionless figure of merit ZT is determined to be about 0.1 at 970 K. Finally, the thermoelectric properties of individual ZnO nanowires are also discussed, indicating that ZnO nanowires are promising high temperature thermoelectric materials.
Electronic Granularity and the Work Function of Transparent Conducting ZnO:Al Thin Films
Authors: Jaramillo Rafael , Ramanathan Shriram
Published: September 2011

Controlling the efficiency of electron transport across oxide interfaces is essential for numerous emerging technologies including advanced photovoltaics and light emitting devices. This work illuminates the connections between granular structure, defect chemistry, and the work function of a technologically important transparent conductor, ZnO:Al. Visual evidence is provided for a model of grain boundary oxidation in the form of nanometer‐scale heterogeneity in the contact potential between grains and grain boundaries, a phenomenon referred to as electronic granularity. By correlating scanning probe data with photoemission spectroscopy we relate electronic granularity to defect chemistry and, importantly, account for the overall trends in work function. The resulting physical picture connects heterogeneity at the nanoscale to macroscopic properties, informs the design of transparent electrodes, and may be broadly relevant to granular oxide conductors.
Efficient Synthesis of Pt Nanoparticles Supported on Hydrophobic Graphitized Carbon Nanofibers for Electrocatalysts Using Noncovalent Functionalization
Authors: Oh Hyung‐Suk , Kim Hansung
Published: September 2011

As an alternative to the oxidative acid treatment, a noncovalent π–π interaction method is employed to deposit Pt electrocatalysts on highly hydrophobic carbon nanofibers (CNFs) for the application of polymer electrolyte membrane (PEM) fuel cells. Three different functionalization agents, namely benzyl mercaptan (BM), 1‐aminopyrene (AP), and 1‐pyrenecarboxylic acid (PCA), are used to functionalize CNFs and the effect of these groups on the electrochemical properties is examined. While the BM and AP act as a poison to Pt catalyst, the functionalization of CNF with PCA improves the distribution and loading of Pt as well as reducing the sintering of Pt particles. From the carbon corrosion test, unlike the oxidative acid treatment, the PCA treatment sustains the corrosion resistance of CNFs because it preserves the intrinsic properties of CNFs without damaging their surface structure. Therefore, the PCA treatment is a very effective way to prepare catalysts for PEM fuel cells and also extended to the fabrication of graphitized‐carbon‐supported catalysts of other precious metal for various applications.
Enamine‐Mediated Addition of Aldehydes to Cyclic Enones
Authors: Schietroma Daniele M. Scarpino , Monaco Mattia R. , Visca Valerio , Insogna Susanna , Overgaard Jacob , Bella Marco
Published: September 2011

The O‐trimethylsilylated α,α‐diphenylprolinol‐catalyzed addition of aldehydes to cyclic unsaturated enones is described. The apparently unusual stereochemical outcome is discussed.
Phosphine‐Free Palladium Catalytic System for the Selective Direct Arylation of Furans or Thiophenes bearing Alkenes and Inhibition of Heck‐Type Reaction
Authors: Chen Lu , Roger Julien , Bruneau Christian , Dixneuf Pierre H. , Doucet Henri
Published: September 2011

Palladium acetate associated to potassium carbonate as catalytic system has been found to efficiently catalyse the direct 5‐arylation of furans or thiophenes bearing enal, enone or acrylate functions at carbon C‐2, and to inhibit the Heck‐type reaction. The nature of the base is crucial to control the selectivity of the arylation. In the presence of electron‐deficient aryl bromides and potassium carbonate as the base, the direct arylation is favoured, whereas the use of potassium fluoride gave selectively the Heck‐type product, and tri‐n‐butylamine the reductive addition product.
Hydroxynitrile Lyase from Arabidopsis thaliana: Identification of Reaction Parameters for Enantiopure Cyanohydrin Synthesis by Pure and Immobilized Catalyst
Authors: Okrob Daniel , Paravidino Monica , Orru Romano V. A. , Wiechert Wolfgang , Hanefeld Ulf , Pohl Martina
Published: September 2011

The (R)‐selective hydroxynitrile lyase from Arabidopsis thaliana (AtHNL) is a promising biocatalyst for the synthesis of a broad range of chiral cyanohydrins. However, the enantiomeric excess of the reaction is strongly compromised by a non‐catalyzed side reaction resulting in racemic cyanohydrins besides the chiral product obtained by enzymatic catalysis. This reaction is influenced by the pH value, the temperature and the water content of the reaction medium. In aqueous media this side reaction can be suppressed at low pH (4–5) and by lowering the temperature. However both approaches are not possible with AtHNL, since the enzyme is rapidly inactivated below pH 5.4, which prevents its use in aqueous media or two‐phasic aqueous‐organic reaction systems. Alternatively the side reaction can be suppressed by lowering the water concentration in the reaction system as far as possible. This approach was successfully tested for AtHNL using buffer‐saturated methyl tert‐butyl ether (MTBE) as a reaction medium for the hydrocyanation of aromatic, heteroaromatic and aliphatic aldehydes. Here we compare the activity and stability of AtHNL immobilized on celite (celite‐AtHNL) and in solgel (solgel‐AtHNL) relative to the precipitated enzyme, which was directly used in the organic solvent. Surprisingly, AtHNL was activated (up to 10‐fold) upon solgel immobilization, an effect that was up to now only described for solgel‐immobilized lipases. In contrast to lipases, AtHNL is not stabilized by the solgel. Best results were obtained with AtHNL adsorbed on celite, which is an easy and efficient way of immobilization and shows good recyclability (>5 cycles), storability (τ1/2=71 days, 4 °C) and excellent catalytic properties upon adjustment of a relative water content of 26% water per g celite‐AtHNL as determined by thermogravimetry.
Synthesis of Enantiomerically Enriched Dimers of Vinylphenols by Tandem Action of Laccases and Lipases
Authors: Gavezzotti Paolo , Navarra Cristina , Caufin Stefania , Danieli Bruno , Magrone Pietro , Monti Daniela , Riva Sergio
Published: September 2011

The tandem use of laccases and lipases has been exploited for the simple preparative synthesis of enantiomerically enriched dimeric phenols. Laccase‐catalyzed oxidation of isoeugenol (1) and vinylguaiacol (7) in biphasic systems gave as main products the racemic compounds 6 and 8, possessing structures similar to the β‐5 dimers found in lignin. The synthesis of enantiomerically enriched 6 and 8 could be achieved by alcoholysis reactions catalyzed by commercial preparations of lipases in organic solvents. Although the E values were quite low (due to the “remote” stereocenters to be discriminated), the enantio‐complementary behavior of the tested lipases allowed the simple isolation of the target compounds with ee up to 90%. It is noteworthy that these results have been achieved in vitro exploiting commercially available enzymes, without using the so‐called “dirigent” proteins evolved by nature to direct the enantioselective coupling of phenols in vivo.
An Efficient Dynamic Kinetic Resolution of N‐Heterocyclic 1,2‐Amino Alcohols
Authors: Lihammar Richard , Millet Renaud , Bäckvall Jan‐E.
Published: September 2011

A chemoenzymatic dynamic kinetic resolution (DKR) of N‐heterocyclic amino alcohols is described. Various lipases were studied as biocatalysts for the kinetic resolution of N‐heterocyclic 1,2‐amino alcohols. The influence of the support of the enzymes on the enantioselectivity in the resolution of different substrates is highlighted. Various 3‐acetoxypyrrolidines and ‐piperidines were obtained in high yield and high enantiomeric excess in efficient DKR reactions.
Microwave material processing—a review
Authors: Chandrasekaran S. , Ramanathan Srinivasan , Basak Tanmay
Published: September 2011

Microwave heating is caused by the ability of the materials to absorb microwave energy and convert it to heat. This article represents a review on fundamentals of microwave heating and their interaction with materials for various applications in a comprehensive manner. Experimental studies of single, multimode, and variable frequency microwave processing were reviewed along with their applications. Modeling of microwave heating based on Lambert's law and Maxwell's electromagnetic field equations have also been reviewed along with their applications. Modeling approaches were used to predict the effect of resonances on microwave power absorption, the role of supports for microwave heating, and to determine the nonuniformity on heating rates. Various industrial applications on thermal processing have been reviewed. There is tremendous scope for theoretical and experimental studies on the athermal effects of microwaves. Some of the unresolved problems are identified and directions for further research are also suggested. © 2011 American Institute of Chemical Engineers AIChE J, 2012
Two‐dimensional model of methane thermal decomposition reactors with radiative heat transfer and carbon particle growth
Authors: Caliot Cyril , Flamant Gilles , Patrianakos Giorgos , Kostoglou Margaritis , Konstandopoulos Athanasios G.
Published: September 2011

A two‐dimensional model of methane thermal decomposition reactors is developed which accounts for coupled radiative heat and polydisperse carbon particle nucleation, growth, and transport. The model uses the Navier–Stokes equations for the fluid dynamics, the radiative transfer equation for methane and particle species radiation absorption, the advection–diffusion equation for gas and particle species transport, and a sectional method for particle species nucleation, heterogenous growth, and coagulation. The model is applied to a tubular laminar flow reactor. The simulation results indicate the development of a reaction boundary layer inside the reactor, which results in significant variation of the local particle size distribution across the reactor. © 2011 American Institute of Chemical Engineers AIChE J, 58: 2545–2556, 2012
Surface modification of polythiophene and poly(3‐methyl thiophene) films by graft copolymerization
Authors: Liu Fangjun , Chen Yubo , Wei Yuyan , Li Liang , Shang Songmin
Published: September 2011

Polythiophene (PTH) and poly(3‐methyl thiophene) (PMT) films were electrochemically polymerized in an electrolyte solution of boron fluoride–ethyl ether. Ozone‐pretreated PTH and PMT films were subjected to UV‐light‐induced graft copolymerization with different monomers, including poly(ethylene glycol) monomethacrylate, acrylic acid, and glycidyl methacrylate. Surface grafting with the hydrophilic polymers gave rise to more hydrophilic PTH and PMT films. The structure and chemical composition of each copolymer surface were studied by X‐ray photoelectron spectroscopy. The surface grafting with the hydrophilic polymers resulted in a more hydrophilic PTH film. The dependence of the density of surface grafting and the conductivities of the grafted PTH and PMT films on the ozone pretreatment was also studied. A large amount of the grafted groups at the surface of the PTH and PMT films remained free for further surface modification and functionalization. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Diazotization of anilines and diazo coupling with a coupling component mediated by a polymer‐supported sodium nitrite and a polymeric acid
Authors: Karimi Zarchi Mohammad Ali , Karimi Mohammad
Published: September 2011

Polymer‐supported reagents have become the subject of considerable and increasing interest as insoluble materials in the organic synthesis. In this study, diazonium salts are generated and are coupled with a coupling component by using a polymer supported nitrite and a polymeric acid. In this procedure, the azo chromophores are formed in a clean and efficient manner, the work–up is easy and yields are high to excellent. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Phase transformation mechanisms and piezoelectric properties of poly(vinylidene fluoride)/montmorillonite composite
Authors: Zhang Y. Y. , Jiang S. L. , Yu Y. , Xiong G. , Zhang Q. F. , Guang G. Z.
Published: September 2011

Poly(vinylidene fluoride) (PVDF)/montmorillonite (MMT) composite with different MMT contents were prepared by solutions‐casting method. The effects of MMT on crystalline structure, morphology, dielectric property, piezoelectric property and phase transformation mechanism were studied. The results showed that acted as effective nucleation agents, the orientation of MMT were almost parallel to the surface of the film. The beta phase in the PVDF matrix was increased and the alpha phase was decreased. Relative dielectric constant and loss of the composite were increased with the increasing of MMT. The d33 was also increased with MMT, which reached a maximum (5.8pC/N) with 2.0 wt % MMT. The mechanisms of changes in phase transformation and piezoelectric property were proposed based on experiment results. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Surface modification of ultra‐flat polydimethylsiloxane by UV‐grafted poly(acrylic acid) brushes
Authors: Yang HaiJun , Hou ZhengChi , Hu Jun
Published: September 2011

The graft density and surface topography of ultra‐flat polydimethylsiloxan films grafted with poly(acrylic acid) brushes by UV irradiation are investigated. The graft density keeps increase with the irradiation time and with the monomer concentration to a maximum, after which it remains unchanged in the former case or drops in the latter. Atomic force microscopy results show that a longer irradiation time, a higher monomer concentration and the addition of ethanol in the grafting solution are favorable to obtain the grafted polydimethylsiloxan films with flat surface. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Synthesis, characterization of the luminescent lanthanide complexes with copolymer of (Z)‐4‐oxo‐4‐phenyloxyl‐2‐butenoic acid and styrene
Authors: Li Tong , Su Yi‐Bing , Huang Yong , Yang Ying
Published: September 2011

The copolymers of (Z)‐4‐oxo‐4‐phenoxyl‐2‐butenoic acid with styrene (PSt/OPBA) and their macromolecular luminous lanthanide complexes (Ln‐PSt/OPBA) have been synthesized and characterized by means of GPC, elemental analysis, FTIR, X‐ray powder diffraction, spectral analysis, and thermal analysis. The IR studies showed that the carboxylic groups on the side chain of the polymer were coordinated to lanthanide ions by bidentate manner. However, the ethereal oxygen, instead of carbonyl, also bonded to the central lanthanide ions, which was an intriguing phenomenon for ester‐coordinated complexes. X‐ray diffraction experiments revealed that these PSt/OPBA copolymers were amorphous, but Ln‐PSt/OPBA were crystalline, in which the complex Eu‐Lc belonged to a high symmetric structure of orthorhombic quadratic system, with a = 10.59 ± 0.02 Å, c = 8.02 ± 0.01 Å; c/a = 0.763. In addition, the value δ (the number of free carboxylic groups) in Ln‐PSt/OPBA complexes increased with the decreasing mole ratio of styrene in the copolymers, while it decreased with increasing pH values of the solution. Eu3+ and Tb3+ complexes exhibited characteristic fluorescence with comparatively high brightness and good monochromaticity, and the fluorescence intensity was enhanced with increasing the content of lanthanide up to around 18 wt % without typical fluorescence concentration quenching behavior in the solid state. So using polymers as a matrix, Ln‐PSt/OPBA are likely to provide new materials that possess specific properties and desired features. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
The physical properties of carbon nanoparticles dispersed into NBR/LLDPE nanocomposites for corrosion protection applications
Authors: Mahmoud Waleed E.
Published: September 2011

In 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

Interpenetrating 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

In 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

In 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

In 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

In 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

A 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

Three 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

Objective

The 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).

Methods

Normal 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.

Results

Comparative 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.

Conclusion

In 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

Objective

To 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).

Methods

Twenty‐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.

Results

Overall 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.

Conclusion

Subclinical 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

The 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.