bluuebunny/crossref_metadata_2025 huggingface dataset:
Preparation and properties investigation of PMMA/silica composites derived from silicic acid
Authors: Fu H. P. , Hong R. Y. , Zhang Y. J. , Li H. Z. , Xu B. , Zheng Y. , Wei D. G.
Published: December 2008

Hybrid materials based on silicic acid and polymethyl methacrylate (PMMA) were prepared by in situ bulk polymerization of a silicic acid sol and MMA mixture. Silicic acid sol was obtained by tetrahydrofuran (THF) extraction of silicic acid from water. Silicic acid was prepared by hydrolysis and condensation of sodium silicate in the presence of 3.6 M HCl. As a comparative study, PMMA composites filled by silica particles, which were derived from calcining the silicic acid gel, were prepared by a comparable in situ polymerization. Each set of PMMA/silica composites was subjected to thermal and mechanical studies. Residual THF in PMMA/silicic acid composites impacted the properties of the polymer composites. With increase in silica content, the PMMA composites filled with silica particles showed improved thermal and mechanical properties, whereas a decrease in thermal stability and mechanical strength was found for PMMA composites filled with silicic acid dissolved in THF. With a better compatibility with polymer matrix, silicic acid sol shows better reinforcement than silica particles in PMMA films prepared via blending of the corresponding THF solutions. Copyright © 2008 John Wiley & Sons, Ltd.
Photopolymerization of alicyclic methacrylate hydrogels for controlled release
Authors: Han Jing , He Yong , Xiao Ming , Ma Guiping , Nie Jun
Published: December 2008

Alicyclic hydroxy methacrylate monomer, o‐hydroxycyclohexyl methacrylate (HCMA), was synthesized and characterized by Fourier transformed infrared spectroscopy (FT‐IR) and proton nuclear magnetic resonance spectroscopy (1H‐NMR). Photopolymerization kinetics of HCMA was investigated via real‐time infrared spectroscopy (RT‐IR). Polymeric network hydrogels based on hydroxyethyl methacrylate (HEMA) and HCMA were prepared by using the photopolymerization technique. Mechanical strength, swelling characteristic, and controlled release behavior of hydrogels with various feed compositions were studied. Poly(HEMA‐co‐HCMA) hydrogel had higher storage modulus than that of poly(HEMA) hydrogel as investigated by dynamic mechanical analysis (DMA). Acid orange 8 was used as a model drug for the investigation of drug release behavior of copolymeric hydrogels. Results indicated that increase in HCMA ratio in hydrogel composition could reduce the swelling rate and prolong the release time. Scanning electron microscopy (SEM) was also utilized to study the surface morphology of hydrogels, and the results indicated that HCMA content influenced pore diameter on the hydrogel surface. Copyright © 2008 John Wiley & Sons, Ltd.
Composite thin films of poly(phenylene oxide)/poly(styrene) and PPO/silver via vapor phase deposition
Authors: Bayer I. S. , Biswas A. , Tripathi A. , Avasthi D. K. , Singh J. P. , Megaridis C. M.
Published: December 2008

We report fabrication of thin (100∼300 nm) poly(phenylene oxide) (PPO) films and their composites with poly (styrene) (PS) and silver (Ag) nanoparticles using a one‐step electron beam‐assisted vapor phase co‐deposition technique. Surface morphology and the structure of the deposited polymer thin film composites were characterized by FTIR, Raman, X‐ray spectroscopy, and contact angle measurements. As‐deposited PPO films and PPO/Ag composites were of porous nature and contrary to solvent casting techniques were free from nodular growth. In the case of PPO/PS thin film polymer composites, however, film morphology displayed nodular growth of PPO with nodule diameters of about ∼200 nm and height of approximately 50 nm. Unique morphological changes on the porous PPO thin film surface were noticed at different Ag filling ratios. Further, the capacitance of PPO/Ag composites (<16 wt%) were measured under radio‐frequency conditions and they were functional up to 100 MHz with an average capacitance density of about 2 nF/cm2. The fabricated PPO‐based composite systems are discussed for their potential applications including embedded capacitor technology. Copyright © 2008 John Wiley & Sons, Ltd.
Preparation and barrier properties of the microcapsules added nanoclays in the wall
Authors: Chuanjie Fan , Xiaodong Zhou
Published: December 2008

Preparation of microcapsules applied to the fabrication of self‐healing composites has attracted a lot of attention. However, the leakage of core material from the microcapsule is a major problem in self‐healing microcapsules. Proper dispersion of layered silicates within the wall of microcapsule is a strategy for improving the barrier properties of the microcapsule. In the present study, poly(urea‐formaldehyde) (PUF) microcapsules containing dicyclopentadiene (DCPD) were prepared by in situ polymerization. For the preparation of UF/clay nanocomposite microcapsules, acid‐modified montmorillonite (H‐MMT) was used as an effective catalyst for the condensation of urea and formaldehyde, and the condensation polymerization in the galleries resulted in the delamination of the clay, as confirmed by TEM and XRD analysis. Scanning electron microscopy (SEM) was applied to observe the morphology of the microcapsules and the barrier property of microcapsules was investigated by thermal gravimetry (TG) analysis and mass release method. On comparison with conventional microcapsules (CMs), nanocomposite microcapsules (NCMs) have better barrier property. This can be attributed to the nanocomposite structure of the microcapsules, where nanosized montmorillonite dispersed in UF to decrease the core material cross‐over. Copyright © 2008 John Wiley & Sons, Ltd.
Preparation of nano‐chitosan Schiff‐base copper complexes and their anticancer activity
Authors: Wang Rong‐Min , He Nai‐Pu , Song Peng‐Fei , He Yu‐Feng , Ding Lan , Lei Zi‐Qiang
Published: December 2008

A new kind of nano‐chitosan Schiff‐base Cu complexes with particle sizes of 350 nm were prepared by combination of nano‐chitosan, Cu and Schiff‐base, and characterized by FT‐IR spectra, TEM, DLS and elemental analysis. The modes and mechanism of interaction of the copper complexes with DNA were studied by the fluorescent probe method and electrophoresis analysis. The results suggest that the Cu complexes bound to DNA by electrostatic and intercalation modes. The anticancer activity of the Cu complexes was evaluated by Sulforhodamine B (SRB) assay in vitro. Nano‐chitosan and their Schiff‐base Cu complexes inhibited the growth of the liver cancer cell lines SMMC‐7721 in vitro. The inhibition rate of Schiff‐base Cu complexes was higher than that of nano‐chitosan. Nano‐chitosan combining with Schiff‐base and Cu improved their anticancer activity, which ascribed to the synergistic effect between the chitosan matrix and the planar construction of the Cu complexes. Copyright © 2008 John Wiley & Sons, Ltd.
Bilateral primary renal lymphoma with orbital metastasis in a child
Authors: Jindal Bibekanand , Agarwala Sandeep , Bakhshi Sameer , Jain Vaibhav , Gupta Arun Kumar , Kumar Rakesh , Bal Chandra Shekhar , Iyer Venkateswaram K. , Gupta Siddharth Datta
Published: December 2008

Primary renal lymphoma (PRL) is a rare condition and bilateral PRL even rarer. Most of these bilateral PRL have been reported in adults. We describe a 3‐year‐old male with bilateral primary renal B cell lymphoma with orbital metastases. We discuss the difficulties in diagnosis and management of this rare presentation of lymphoma. Pediatr Blood Cancer 2009;52:539–541. © 2008 Wiley‐Liss, Inc.
Therapy and outcome of orbital primitive neuroectodermal tumor
Authors: Bakhshi Sameer , Meel Rachna , Naqvi Syed Ghaffar Hasan , Mohanti B.K. , Kashyap Seema , Pushker Neelam , Sen Seema
Published: December 2008

Primary orbital primitive neuroectodermal tumor (PNET) is rare with no reported series. We report six cases of orbital PNET treated at a tertiary care oncology center in northern India from 2003 to 2008. None of them had distant metastases. All were treated with neoadjuvant chemotherapy followed by exenteration in two, radiotherapy and adjuvant chemotherapy in five cases. Three out of six achieved complete remission at end of therapy with globe salvage in three and vision in two cases. Chemoradiotherapy may help us to avoid mutilating surgery in large or locally advanced tumors, allowing preservation of vision or the globe. Pediatr Blood Cancer 2009;52:544–547. © 2008 Wiley‐Liss, Inc.
Tracing survivors of childhood cancer in Australia
Authors: Wilson Carmen L. , Cohn Richard J. , Johnson Karen A. , Ashton Lesley J.
Published: December 2008

Background

A major challenge when establishing a retrospective cohort of childhood cancer survivors is maximizing the enrolment of individuals treated as children. In Australia, several public databases can facilitate tracing of childhood cancer survivors; these include the Births, Deaths and Marriage Registers (BDMR), the telephone white pages (EWP), and the Australian Electoral Roll (AER). The aim of this study was to evaluate the characteristics of survivors traced for a cohort study examining the late effects of childhood cancer.

Procedure

Eligible participants included 1,198 individuals treated for cancer during childhood at Sydney Children's Hospital. Of these, 1,156 individuals were confirmed alive and subsequently traced by cross matching against the AER, BDMR, WP, and clinical records. Characteristics influencing the likelihood of tracing were evaluated using logistic regression analyses.

Results

Current addresses were obtained for 810 (70.1%) survivors. Overall, those diagnosed within the last decade were more easily traced than those diagnosed in an earlier decade (Test for trend, P < 0.01). In addition, older age at diagnosis and diagnosis of a sympathetic nervous system or renal malignancy were associated with a decreased likelihood of tracing in survivors, aged ≥18 years (P < 0.05). In survivors aged <18 years, age at diagnosis, sex, and cancer diagnosis were not associated with the likelihood of tracing (P > 0.05).

Conclusions

Our findings show that cancer type and year of diagnosis are independent factors influencing the ability to trace survivors of childhood cancer. Linkage to public databases provides a unique opportunity to recruit a representative hospital‐based cohort of childhood cancer survivors in Australia. Pediatr Blood Cancer 2009;52:510–515. © 2008 Wiley‐Liss, Inc.
Pediatric Hodgkin lymphoma survivors at negligible risk for significant bone mineral density deficits
Authors: Kaste Sue C. , Metzger Monika L. , Minhas Anum , Xiong Zang , Rai Shesh N. , Ness Kirsten K. , Hudson Melissa M.
Published: December 2008

Background

We hypothesized that pediatric Hodgkin lymphoma (HL) survivors would have bone mineral density (BMD) deficits compared to their peers because of osteotoxic chemotherapy during the time of greatest BMD accretion.

Methods

We retrospectively reviewed records of HL survivors returning for follow‐up between 1990 and 2002. Of the 133 eligible survivors, 109 who underwent quantitative computed tomography (QCT) comprised the study group. QCT‐determined BMD Z‐scores were correlated with patient characteristics and therapeutic exposures by Wilcoxon rank sum or Chi‐square tests. Logistic regression models were used to explore risk factors for diminished BMD.

Results

The study cohort was half male (50.5%) and 85.3% reported their race as white. Participants were representative of all survivors potentially eligible for study, except that more study participants were female, had hypothyroidism, and had received cyclophosphamide. Median age at diagnosis was 15.1 years (range, 3.1–20.7 years); median time between diagnosis and QCT was 7.5 years (range, 5.0–12.4 years). The proportion of HL survivors with BMD below the mean did not significantly differ from the general population (P = 0.503). However, those with BMD −1.5 SD and BMD −2.0 SD or lower (14.7% and 7.3%, respectively) exceeded that in the general population (6.7% and 2.3%, respectively; P < 0.001 for both degrees of severity). Males, diagnosed at 14 years or older, were at 6.5 times higher risk than females (OR 95% CI: 1.24–34.14; P = 0.027) for BMD deficits.

Conclusions

Overall, pediatric HL survivors had negligible BMD deficits. Male gender was associated with an increased risk of developing BMD deficits. Pediatr Blood Cancer 2009;52:516–521. © 2008 Wiley‐Liss, Inc.
Synthesis and properties of water soluble single‐walled carbon nanotube graft ionic polyacetylene nanocomposites
Authors: Ku Bon‐Cheol , Kim Dae Kyom , Lee Jun Seok , Blumstein Alexandre , Kumar Jayant , Samuelson Lynne A.
Published: December 2008

Water‐soluble single‐walled carbon nanotube‐polyacetylene [SWNT‐PA, SWNT‐P(2EPy‐MeTf)] nanocomposites have been synthesized by using the surface initiated “grafting‐from” method. The FT‐IR spectra confirmed the formation of an amide bond between the functionalized SWNTs and the initiator, 4‐(2‐Aminoethyl) pyridine, to polymerize N‐Methyl‐2‐ethynlypyridinium triflate (2EPy‐MeTf). UV‐vis spectroscopy indicated that the degree of polymerization of P(2EPy‐MeTf) in the SWNT‐polyacetylene composites is 15, based on the Lewis‐Calvin equation. The SWNT‐polyacetylene composites have been characterized by TGA, AFM, and TEM. From TGA analysis, the loading of SWNTs in the SWNT grafted ionic polyacetylenes is estimated to be 22%. AFM and TEM images clearly showed that the nanotube is wrapped with the PA. The SWNT‐polyacetylene composites displayed high water solubility (8 mg/ml). The room temperature electrical conductivity of the doped SWNT‐polyacetylene composites was found to be in the range of 10−3 to 10−4 S/cm, an order of magnitude of increase over neat P(2EPy‐MeTf) and a two order of magnitude increase over Dendrimer‐polyacetylen composites. POLYM. COMPOS., 2009. © 2008 Society of Plastics Engineers
PLAC4 and β‐HCG mRNA levels are not altered in the maternal circulation of pregnancies with trisomy 21
Authors: Banzola Irina , Rusterholz Corinne , Zannoni Letizia , Rizzo Nicola , Zhong Xiao Yan , Caramelli Elisabetta , Holzgreve Wolfgang , Farina Antonio , Hahn Sinuhe
Published: December 2008

Objective

β‐Human chorionic gonadotropin (HCG) and pregnancy‐associated plasma protein (PAPP‐A) are placentally produced proteins whose levels are altered in pregnancies with trisomy 21. PLAC4 is located on chromosome 21 and its expression is restricted to the placenta. Here we investigated whether the levels of β‐HCG‐, PAPP‐A‐ and PLAC4 mRNA could be able to discriminate pregnancies whose fetus is affected by trisomy 21.

Method

Hundred and forty‐three blood samples from normal pregnancies and eight samples from trisomic pregnancies were collected. Total RNA was extracted from whole maternal blood, reverse‐transcribed and the three mRNAs were quantified by real‐time quantitative PCR. Hundred and nine controls were also tested for the serum levels of PAPP‐A and HCG proteins.

Results

β‐HCG and PLAC4 mRNAs were detected in all samples, in higher amounts than in plasma, whereas the detection rate for PAPP‐A mRNA was below 10%. The levels of β‐HCG mRNA significantly correlated with the circulatory concentrations of the HCG protein. However, neither β‐HCG‐ nor PLAC4 mRNAs show a significant difference between cases and controls.

Conclusion

Maternal blood levels of β‐HCG‐, PLAC4‐ and PAPP‐A mRNAs are not useful markers for the screening of pregnancies with trisomy 21 as their concentrations are either not significantly altered (β‐HCG and PLAC4) or too low to be detected (PAPP‐A). Copyright © 2008 John Wiley & Sons, Ltd.
Prevention of homozygous beta thalassemia by premarital screening and prenatal diagnosis in India
Authors: Tamhankar Parag M. , Agarwal Sarita , Arya Vandana , Kumar Ravindra , Gupta U. R. , Agarwal S. S.
Published: December 2008

Aim

To determine the feasibility and acceptability of premarital screening for beta thalassemia/related hemoglobinopathies followed by prenatal diagnosis in India.

Materials and Methods

Premarital testing for thalassemia carrier state was carried out in (1) extended family members (EFM) of diagnosed cases of thalassemia/hemoglobinopathies, (2) unmarried adult cases of anemia attending the hospitals' outpatient department (OPD) and (3) adult college students (CG). Hemoglobin, red cell indices were measured by a cell counter and hemoglobin fractionation was carried out by high performance liquid chromatography (HPLC). In cases with HbA2 > 3.5%, or with variant hemoglobin, mutation screen was done by amplification refractory mutation system polymerase chain reaction (ARMS‐PCR). In high‐risk prospective couples, premarital genetic counseling was done and prenatal diagnosis possibilities were explained.

Results

The yield of carriers from EFM, OPD and CG groups was 78.17% (308/394), 19.51% (263/1348) and 4.04% (38/939), respectively. The number of prospective high‐risk couples detected were 154, 48 and 2 from EFM, OPD and CG, respectively. As much as 99% of prospective carrier couples married even after knowing their high‐risk status and opted for prenatal diagnosis. The program averted the birth of 33 thalassemic children; 28 in EFM group (by screening of 394 individuals), 4 in the OPD group (by screening 1348 anemic patients), and 1 in CG group (by screening of 939 students).

Conclusion

Premarital screening in extended family members, followed by prenatal diagnosis is acceptable and the most effective strategy for control of thalassemia in developing countries like India. Copyright © 2008 John Wiley & Sons, Ltd.
Validating a method that deals with missing drug information in the Saskatchewan Drug Plan database
Authors: Tamim Hani M. , Tagalakis Vicky
Published: December 2008

Introduction

An important limitation of Saskatchewan Drug Plan is the incomplete prescription data during an 18‐month period (1987–1988), referred to here as the “black‐hole”.

Objective

To assess the impact of assuming drug non‐exposure during the “black‐hole” on measures of effect.

Methods

We used data from a matched case‐control study carried out to assess the association between warfarin use and risk of prostate cancer. All subjects diagnosed with prostate cancer between 1981 and 2002 were matched to six controls. In order to avoid the “black‐hole”, we included subjects whose cancer was diagnosed after 1994. Conditional logistic regression was used to calculate adjusted incidence rates and 95% confidence intervals (CIs) of prostate cancer in relation to warfarin. Two analyses were carried out: (a) without a “black‐hole” and (b) with a random “black‐hole” of 18 months imposed in the drug history, during which time subjects were assumed to be unexposed.

Results

Compared to non‐use, the OR of prostate cancer for ever‐use of warfarin in the preceding 5 years was 0.91 (95%CI: 0.81–1.02) (without “black‐hole”) and 0.89 (95%CI: 0.79–1.01) (with “black‐hole”). Compared to non‐use, cumulative use of 1, 2, 3, and 4 years were associated with ORs of 1.02, 0.94, 0.77, and 0.76, respectively in the analyses without a “black‐hole”, and 1.02, 0.88, 0.75, and 0.76, respectively in the analyses with a “black‐hole” imposed.

Conclusion

When using Saskatchewan Drug Plan data, assuming non‐exposure to warfarin during the “black‐hole” has a minor effect on the measures of association. Copyright © 2008 John Wiley & Sons, Ltd.
Poly[(3‐hydroxybutyrate)‐co‐(3‐hydroxyvalerate)]/layered double hydroxide nanocomposites
Authors: Dagnon Koffi L , Chen Hua H , Innocentini‐Mei Lucia H , D'Souza Nandika A
Published: December 2008

BACKGROUND: The thermomechanical performance of poly[(3‐hydroxybutyrate)‐co‐(3‐hydroxyvalerate)] (PHBV) is associated with its crystallization. Enhanced nucleation using a stearate‐functionalized synthetic layered double hydroxide (LDH) presents a potential solution.

RESULTS: PHBV crystallization varied with concentration of LDH. At lower LDH concentration, thermal history‐induced cold crystallization was present. The extent of this order–disorder transition decreased with increasing LDH concentration and was completely eliminated at 7 wt% LDH. PHBV did not have a melt recrystallization peak but the introduction of LDH resulted in an increasingly pronounced melt recrystallization with increasing LDH concentration. Polarized optical microscopy coupled with differential scanning calorimetry and wide angle X‐ray diffraction (WAXD) analysis indicated increased lamella thickness in the nanocomposites compared to pure PHBV. WAXD and transmission electron microscopy showed that the nanocomposites had an intercalated but aggregated dispersion.

CONCLUSION: The concentration of nanofiller provides unique effects in PHBV. Mechanical performance was found to scale with composition as determined using dynamic mechanical analysis and tensile testing. Copyright © 2008 Society of Chemical Industry
Swelling mechanism of porous P(VP‐co‐MAA)/PNIPAM semi‐IPN hydrogels with various pore sizes prepared by a freeze treatment
Authors: Jin Shuping , Bian Fengling , Liu Mingzhu , Chen Shilan , Liu Hongliang
Published: December 2008

BACKGROUND: The objective of the work reported was to investigate the effect of gel microstructure on the swelling mechanism. A series of porous gels with various pore sizes were prepared by freeze‐treating a conventional hydrogel that contained various amounts of water at − 20 °C. Scanning electron microscopy and differential scanning calorimetry were used to characterize the microstructure of the porous gels.

RESULTS: The experimental results showed that the water content during freezing was the key factor controlling the microstructure. Measurement of swelling kinetics showed that a greater amount of water during the freezing process would lead to a rapid swelling rate. The apparent diffusion coefficients (Dp) at all times during the swelling process were obtained by fitting the experimental data to the diffusion equation. The values of Dp suggested that the swelling mechanism of the gels depends on the pore size. The diffusion exponent (n) obtained by fitting the fractional mass change (Mt/M∞) to equation of Fick's law further confirmed that the swelling mechanism of the gels is determined by the pore size.

CONCLUSION: The swelling mechanism of the gels is determined by the microstructure related to the pore size and the thickness of struts. The microstructure can be controlled by adjusting the water content of the hydrogels by changing the pH of the swelling medium prior to freezing. Copyright © 2008 Society of Chemical Industry
Photochromic properties of polyimide and polysiloxane azopolymers
Authors: Sava Ion , Sacarescu Liviu , Stoica Iuliana , Apostol Ileana , Damian Victor , Hurduc Nicolae
Published: December 2008

BACKROUND: One of the most important properties of the azobenzene chromophores is the photochemical trans–cis isomerization induced by UV or visible light. In azopolymers, the photoisomerization induces conformational changes in the polymer chains, which in turn lead to macroscopic variations in the chemical and physical properties of the surroundings and media.

RESULTS: This work reports the photochromic behaviour and surface structuring capacity of azopolymers having rigid polyimide and flexible polysiloxane structures, respectively. These polymers have good thermostabilities, with the degradation process starting above 315 °C. The glass transition temperature of the azopolyimide is 228 °C, while that of the azopolysiloxane modified with thymine is 34 °C.

CONCLUSION: The experiments show that the azobenzene groups can isomerize even in the case of the rigid polyimide, but the maximum degree of conversion to the cis isomer is less than in the case of the flexible polysiloxane. This behaviour is reversed in solution, probably due to both the thymine and azo group interactions and for conformational reasons. The azopolymers show a good surface structuring capacity. The polysiloxane is more sensitive in the case of low irradiation energy and irradiation time. By increasing the irradiation time for both polymers, the modulation depth increases and has comparable values. Copyright © 2008 Society of Chemical Industry
Peer victimization in children with Attention‐Deficit/Hyperactivity Disorder
Authors: Wiener Judith , Mak Meghan
Published: December 2008

This study explored peer victimization in 9‐ to 14‐year‐old children with and without Attention‐Deficit/Hyperactivity Disorder (ADHD). The sample comprised 104 children, 52 of whom had a previous ADHD diagnosis. Children with ADHD had higher overall rates of self‐reported victimization by peers and parent‐ and teacher‐reported bullying behavior than did children without ADHD. The rates of victimization were especially high for girls with ADHD. Furthermore, children with ADHD reported higher frequencies of verbal, physical, and relational victimization than did children without ADHD. When data were pooled from children, parents, and teachers, children with ADHD were categorized as victims, bullies, and bully/victims significantly more often than were children without ADHD. Parent ratings of ADHD symptoms predicted self‐reported victimization by peers. Neither parent‐rated anxious‐shy behaviors nor parent‐ and teacher‐rated social skills predicted victimization by peers over and above ADHD symptoms. Parent ratings of oppositional behavior mediated the relationship between ADHD symptoms and parent‐ and teacher‐rated bullying. © 2008 Wiley Periodicals, Inc.
Enthalpies of formation and isomerization of aromatic hydrocarbons and ethers by G3(MP2)//B3LYP calculations
Authors: Taskinen Esko
Published: December 2008

A computational method for estimation of the gas‐phase enthalpies of formation of aromatic hydrocarbons and ethers has been developed. The method is based on high‐level G3(MP2)//B3LYP calculations, atomization reactions, and structure‐dependent correction terms. By this method, enthalpies of formation ΔfHm°(g, 298.15 K) of 86 aromatic compounds were evaluated. The calculated enthalpies of formation raise questions of the reliability of several experimental enthalpies of formation reported in the literature. As an application of the computational enthalpies of formation, reaction enthalpies for several types of isomerization reactions of aromatic compounds were calculated. In cases in which experimental reaction enthalpies were available for comparison, the agreement between the computational and experimental data proved to be excellent. Copyright © 2008 John Wiley & Sons, Ltd.
Synthesis of 1H‐quinazoline‐2,4‐diones from 2‐aminobenzonitriles by fixation of carbon dioxide with amidine moiety supported polymer at atmospheric pressure
Authors: Nagai Daisuke , Endo Takeshi
Published: December 2008

1H‐Quinazoline‐2,4‐diones, which are key intermediates in the synthesis of medicines, were successfully synthesized from 2‐aminobenzonitriles by the fixation of CO2 in the presence of a polystyrene derivative bearing amidine moiety [poly(amidine)]. A model reaction, that is, the reaction of 2‐aminobenzonitrile (1a) with CO2 in the presence of N‐methyltetrahydropyrimidine (MTHP) revealed that a catalytic amount of MTHP afforded 1H‐quinazoline‐2,4‐dione (2a) quantitatively at atmospheric pressure. Several 1H‐quinazoline‐2,4‐diones (2a‐2c) were successfully synthesized from the corresponding 2‐aminobenzonitriles (1a‐1c) in the presence of poly(amidine). The poly(amidine) could easily be separated from the reaction mixture by filtration and reused in subsequent reactions owing to the heterogeneous system. These demonstrated that poly(amidine) is a useful heterogeneous polymer‐supported reagent for the synthesis of 1H‐quinazoline‐2,4‐diones from CO2. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 653–657, 2009
Nano‐hydroxyapatite/polyamide66 composite tissue‐engineering scaffolds with anisotropy in morphology and mechanical behaviors
Authors: Wang Huanan , Zuo Yi , Zou Qin , Cheng Lin , Huang Di , Wang Li , Li Yubao
Published: December 2008

Based on a biomimetic conception, nano‐hydroxyapatite (n‐HA)/polyamide66 (PA66) composite scaffolds were prepared with anisotropic properties both in morphology and mechanical behavior. A novel improved thermally induced phase separation (TIPS) technique was developed to generate orientation‐structured scaffolds for tissue engineering. The physiochemical, morphological, and mechanical properties of the resultant scaffolds were evaluated. According to the results, the improved TIPS method exhibited good processability and reproducibility and enabled the composite scaffolds to have a high content of inorganic fillers. The morphological study proved that the n‐HA/PA66 scaffolds exhibited unidirectional microtubular architecture with high porosity (ca. 80–85%) and an optimal pore size ranging from 200 to 500 μm. Besides, the effect of n‐HA content on the morphology of the scaffolds was studied, and the results indicated that the obtained scaffolds presented an improvement in anisotropic morphology with increase of n‐HA content. The anisotropy was also evaluated in the mechanical properties of the scaffolds, that is, the longitudinal compressive strength and modulus were ∼1.5 times of the transverse ones. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 658–669, 2009
Thermoplastic amphiphilic conetworks
Authors: Kang Jungmee , Erdodi Gabor , Kennedy Joseph P.
Published: December 2008

Our main objective was the design, synthesis, characterization, and testing of a novel class of materials, thermoplastic amphiphilic conetworks (TP‐APCNs). A further objective was the evaluation of TP‐APCNs as biomaterials, for example, as immunoisolatory membranes in a bioartificial pancreas, or as extended‐wear soft contact lenses. The synthesis of the first TP‐APCNs was accomplished by blending an amphiphilic graft polymer, poly(dimethyl acryl amide)‐g‐polydimethylsiloxane (PDMAAm‐g‐PDMS), with a commercial PDMS‐containing polyurethane (PU). The common PDMS segments coalesce and form a single phase, whereas the hard/crystalline segments of the PU physically crosslink the blend. The properties of TP‐APCNs can be controlled by the graft/PU ratio and segment molecular weights. TP‐APCNs with cocontinuous hydrophilic and hydrophobic phases were prepared as demonstrated by swelling in water and n‐heptane. Depending on the blend ratio and molecular weights, optically clear water‐swollen TP‐APCNs with 0.5–4 MPa tensile strength, 70–280% elongation, together with 2–11 × 10−7 cm2/s glucose permeability, and 1.2–8 × 10−8 cm2/s insulin permeability were prepared. TP‐APCNs are processible by casting and molding. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 682–691, 2009
Synthesis, characterization, and thermal properties of piezoelectric polyimides
Authors: Gonzalo B. , Vilas J. L. , Breczewski T. , Pérez‐Jubindo M. A. , De La Fuente M. R. , Rodriguez M. , León L. M.
Published: December 2008

Three amorphous piezoelectric polyimides have been synthesized and characterized to analyze their utility for high‐temperature applications. The studied polyimides have been prepared from 4,4′‐oxydiphthalic anhydride and the diamines 2,4‐di(3‐aminophenoxy)benzonitrile (poly2‐4), 2,6‐bis(3‐aminophenoxy)benzonitrile (poly2‐6), and 1,3‐bis‐2‐cyano‐3‐(3‐aminophenoxy)phenoxybenzene (poly2CN). These polyimides differ in the position of the dipolar groups CN in the aromatic ring (poly2‐4 and poly2‐6) and in the number of these groups in the repetitive unit (poly2‐6 and poly2CN). The imidization degree has been studied by Fourier transform infrared (FTIR) and thermogravimetry‐mass spectrometry (TG‐MS) and thermal properties by differential scanning calorimetry (DSC) and thermogravimetry (TG). The piezoelectric behavior has been analyzed from remnant polarization measurements. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 722–730, 2009
Influence of number of functional groups of hyperbranched polyol on cure kinetics and physical properties of polyurethanes
Authors: Maji Pradip K. , Bhowmick Anil K.
Published: December 2008

Curing of polyurethane prepolymer with three hyperbranched polyol was studied using FTIR spectroscopy. The disappearance of the strong isocyanate absorption peak was followed with time and temperature to determine the reaction kinetics. It was shown that all the hyperbranched polyols followed the second order kinetic equation and the reaction rate enhanced with increase in the number of the functional groups of the hyperbranched polyol. Activation energy, activation enthalpy, and activation entropy were also measured. The swelling character of the polyurethanes was investigated with the help of gel fraction, degree of crosslinking, and average molecular weight between crosslinks. Atomic force microscopy indicated phase separated morphology of the cured polyurethanes. The thermal, mechanical, and thermomechanical properties were enhanced when the number of the functional groups in the hyperbranched polyols was increased. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 731–745, 2009
Microemulsion polymerization of cationic pyrroles bearing an imidazolum‐ionic liquid moiety
Authors: Zhao Jie , Yan Feng , Chen Zhenzhen , Diao Hanbin , Chu Fuqiang , Yu Shaomei , Lu Jianmei
Published: December 2008

A cationic pyrrole derivative, N‐(4‐butyl‐(1‐methylimidazole)) pyrrole bromide (Py‐Br) bearing an imidazolium‐type ionic liquid moiety was synthesized. Microemulsion polymerization of Py‐Br in water/oil microemulsions produced poly(N‐(4‐butyl‐(1‐methylimidazole)) pyrrole bromide) (PPy‐Br) nanoparticles. The bromide anion of the resultant PPy‐Br nanoparticles was exchanged in water with different anions, including BF and PF to produce new nanoparticles bearing different counteranions. The results of thermal analysis indicate that the thermal stability of cationic PPy nanoparticles strongly depends on the nature of counteranion. As an application, water‐soluble PPy‐Br with fine fluorescence property was used as a new sensor for DNA detection. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 746–753, 2009
Heterogeneous polymerization with polyaspartate macromonomer having vinyl pendant groups. I. Synthesis of macromonomer and dispersion copolymerization of styrene
Authors: Tomita Keisuke , Ono Tsutomu
Published: December 2008

Sodium polyaspartate (PAspNa) derivatives with vinylbenzyl pendant groups (VBA‐PAspNa) were synthesized by reaction of poly(succinimide) (PSI) and vinylbenzylamine (VBA), and hydrolysis by sodium hydroxide (NaOH) solution. VBA‐PAspNa is a macromonomer with multiple vinyl groups in the side chain. Submicron sized polymeric particles were prepared by dispersion copolymerization of styrene with VBA‐PAspNa in a mixture of ethanol and water. Particle diameter decreased with increasing concentration and vinyl group fraction of VBA‐PAspNa. When compared with the particle diameter prepared using PAspNa or benzylamine‐modified PAspNa (BA‐PAspNa) as a dispersion stabilizer without vinyl groups, the particles prepared with VBA‐PAspNa were an order smaller than those prepared with PAspNa or BA‐PAspNa. The particles after refinement show an adequate negative ζ‐potential. From this result, we clarified the presence of PAspNa chains anchored onto the particle surface. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 762–770, 2009
Polymerization kinetics of rac‐lactide initiated with alcohol/stannous octoate using in situ attenuated total reflectance‐fourier transform infrared spectroscopy: An initiator study
Authors: Moravek Scott J. , Messman Jamie M. , Storey Robson F.
Published: December 2008

rac‐Lactide polymerization kinetics in THF at 72 °C were monitored in real‐time using mid‐infrared ATR‐FTIR spectroscopy, with diamond composite insertion probe and light conduit technology. Monomer concentration as a function of time was acquired using the 1240 cm−1 resonance associated with the COOC stretch. Polymerizations were initiated with either n‐propanol (PrOH), ethylene glycol (EG), trimethylol propane (TMP), or pentaerythritol (PENTA) with the coinitiator stannous octoate (Sn(Oct)2). Polymerizations were found to be reversible at high monomer conversions, with a residual monomer concentration at 72 °C (345 K) of 0.081 M. The polymerizations were internally first‐order with respect to monomer, indicating a constant concentration of propagating centers. For a typical reaction with [rac‐LA]0 = 1.0 M, [PENTA]0 = 1.3 × 10−2 M, and [Sn(Oct)2] = 2.5 × 10−2 M, the first‐order rate constant, kapp was measured as 1.8 × 10−4 s−1. First‐order rate constants were determined to be independent of polymer architecture (i.e., initiator functionality) and proportional to [Sn(Oct)2] for [Sn(Oct)2]0/[ROH]0 ≪ 1, where [ROH]0 represents the initial concentration of initiating hydroxyl groups. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 797–803, 2009
Synthesis and characterization of polypropylene‐based block copolymers possessing polar segments via controlled radical polymerization
Authors: Kaneko Hideyuki , Saito Junji , Kawahara Nobuo , Matsuo Shingo , Matsugi Tomoaki , Kashiwa Norio
Published: December 2008

A new method to prepare the polypropylene (PP) macroinitiator for controlled radical polymerization was described. Bromination of terminally‐unsaturated PP was carried out by using N‐bromosuccinimide and 2,2′‐azobis(isobutyronitrile) to give a brominated PP (PP‐Br), that has allylic bromide moieties at or near the chain ends. Thus, the obtained PP‐Br was successfully used as a macroinitiator for radical polymerization of styrene, methyl methacrylate, and n‐butyl acrylate using a copper catalyst system. From 1H NMR analysis, it was confirmed that the chain extension polymerization was certainly initiated from allylic bromide moieties with high efficiency, leading to the PP‐based block copolymers linking the polar segment. From differential scanning calorimetry, it was observed that peak melting temperature of block copolymers was higher than that of PP‐Br and the obtained PP‐PS block copolymers with different compositions of each segment demonstrated the unique morphological features due to the microphase separation between both segments. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 812–823, 2009
Sexual health issues in Sudanese women before and during hormonal treatment for breast cancer
Authors: Abasher Sanaa M.
Published: December 2008

Objective: Recent Sudanese studies have focused on depression and anxiety in women treated for breast cancer (BrCa). Less is known about whether such women suffer from sexual disturbances due to different cancer treatments. This study compares BrCa patients with a healthy control group and assessed the impact of cancer treatment types.

Methods: The BrCa group included women treated for BrCa with mastectomies, chemotherapy and radiotherapy (N=100). Some received hormonal therapy (N=60) and others had not yet received it (N=40). The control group comprised women who had never had BrCa, non‐BrCa (N=100). Outcomes were assessed using the Watts Sexual Function Questionnaire.

Results: It was found that many women treated for BrCa suffered from sexual disturbances before hormonal treatment while some regained sexual activity during hormonal treatment. Demographic data show negative correlation (P=0.03) between sexual function and age of the patients, positive correlation (P=0.002) between sexual function and educational level and positive correlation (P=0.031) as well between sexual function and the patient's length of marriage.

Conclusion: This study helps to fill the gap in the literature about Sudanese women's sexuality, as many studies indicate the effect of some psychological disturbance (depression and anxiety) and ignoring the effect of sexual function in enhancing patient's quality of life. Copyright © 2008 John Wiley & Sons, Ltd.
Separation and Determination of PETN and TNT by HPTLC
Authors: Chaloosi Marzieh , Nejad‐Darzi Seyed Karim Hassani , Ghoulipour Vanik
Published: December 2008

This article was published in Early View with DOI 10.1002/prep.200800012 – what is wrong. It has appeared with the correct DOI 10.1002/prep.200900012 – in Propellants, Explosives, Pyrotechnics 2009 (34) issue 1/2009 on pp 50‐52.
Lack of fitness costs associated with pyriproxyfen resistance in the B biotype of Bemisia tabaci
Authors: Crowder David W , Ellers‐Kirk Christa , Tabashnik Bruce E , Carrière Yves
Published: December 2008

BACKGROUND: The insect growth regulator pyriproxyfen has provided effective control of the whitefly Bemisia tabaci Gennadius in many countries. Here, whether or not fitness costs were associated with pyriproxyfen resistance in a laboratory‐selected resistant strain (QC02‐R) of the B biotype was determined.

RESULTS: Mortality caused by pyriproxyfen and fitness traits over time were measured in unselected and selected hybrid strains, which were created by crossing individuals of the resistant strain with individuals of a susceptible strain. Fitness costs were not associated with resistance in QC02‐R, as mortality caused by pyriproxyfen did not increase over time in unselected hybrid strains and fitness traits were similar in unselected and selected hybrid strains. Using a new method to examine the inheritance of resistance, based on data from fitness cost experiments, it was estimated that pyriproxyfen resistance is controlled by two loci in the QC02‐R strain.

CONCLUSION: The lack of fitness costs associated with pyriproxyfen resistance could promote the evolution of resistance in field populations with similar traits to QC02‐R. Copyright © 2008 Society of Chemical Industry
Improvement of peptide vectors for gene delivery with active targeting profiles for phosphatidylserine
Authors: Kuriyama Shinichi , Taguchi Yasushi , Nishimura Kanako , Yanagibashi Kazutoshi , Katayama, Yoshiki , Niidoime Takuro
Published: December 2008

A cationic peptide, Td3701, which was derived from factor VIII that has affinity with phosphatidylserine (PS), showed efficient transfection ability for cells that express PS on the cell surface. PS is exposed on tumor cell surfaces therefore we have focused on PS as the target molecule for tumor specific gene delivery. In this article, to improve transfection efficiency and specificity in targeting tumor cells, some amino acid residues of Td3701 were replaced. The resulting peptide, Td3717, shows higher transfection efficiency (more than 30 times that of Td3701). The transfection efficiency was dependent on the amount of PS on the cell surface, suggesting that Td3717 bound with plasmid DNA could recognize PS on the cell surface. Td3717 is expected to be useful as an efficient gene carrier molecule specific to PS‐presenting tumor cells. Copyright © 2008 European Peptide Society and John Wiley & Sons, Ltd.
Interstate migration, spatial assimilation, and the incorporation of US immigrants
Authors: Hall Matthew
Published: December 2008

The recent trend of immigrant geographical diffusion in the United States has increased the relevance of a detailed understanding of the consequences of secondary migration for immigrant families, and a consideration of what is to be learned about immigrant incorporation from their patterns of domestic migration. In this paper, a regional variant of the spatial assimilation model is tested using longitudinal data on immigrant economic well‐being. The results of this research indicate that, like their native counterparts, immigrants benefit, both in terms of employment and earnings, from making interstate moves. Consistent with the spatial assimilation model, immigrants migrating to states with smaller relative foreign‐born populations see additional gains, with higher‐skilled and better‐acculturated immigrants enjoying the greatest returns. Copyright © 2009 John Wiley & Sons, Ltd.
Mining the bulk positron lifetime
Authors: Aourag H. , Guittom A.
Published: December 2008

We introduce a new approach to investigate the bulk positron lifetimes of new systems based on data‐mining techniques. Through data mining of bulk positron lifetimes, we demonstrate the ability to predict the positron lifetimes of new semiconductors on the basis of available semiconductor data already studied. Informatics techniques have been applied to bulk positron lifetimes for different tetrahedrally bounded semiconductors in order to discover computational design rules. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Electronic structure, optical and X‐ray emission spectra in FeS2
Authors: Antonov V. N. , Germash L. P. , Shpak A. P. , Yaresko A. N.
Published: December 2008

The electronic structure, optical spectra, X‐ray emission (XE) and X‐ray absorption (XA) spectra of FeS2 were investigated theoretically from first principles, using the fully relativistic Dirac LMTO band structure method in local density approximation (LDA). Theory produces correct semiconductor ground state in FeS2 with the energy gap of Eg = 0.9 eV in good agreement with the experimental data. Densities of valence states are analyzed and discussed. The origin of the optical, XA and XE spectra in the FeS2 compound is examined. The calculated results are compared with available experimental data. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Novel electronic structure and transport properties of confined disordered carbon layers
Authors: Bhattacharyya Somnath
Published: December 2008

We propose a generalized spectral conductivity model for combined delocalized and localized π‐states of low‐dimensional carbon to explain their temperature dependent conductivity and its crossover. This model also interprets the origin of weakly localized coherent transport in carbon super‐structures such as nano‐crystalline diamond and 2D carbon films. From the enhanced phase coherence length the unique microstructure of these films is revealed. The corresponding electron's dephasing time also shows their potential for fast electronic device applications. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Improved luminescence efficiency of InAs quantum dots grown on atomic terraced GaAs surface prepared with in‐situ chemical etching
Authors: Idutsu Yasuhiro , Miyamura Souta , Suemune Ikuo
Published: December 2008

Observation of the enhanced luminescence efficiency of InAs quantum dots (QDs) grown on atomically controlled GaAs surfaces is reported. With the trisdimethylaminoarsenic (TDMAAs) in‐situ surface etching process, formation of atomic steps and terraces on GaAs surfaces were clearly observed. InAs QDs grown on the processed GaAs surfaces showed the clear dependence of QDs size, density and optical characteristics on the surface properties, i.e., the increase of the QDs height and diameter the decrease of the QDs density. About 6‐times enhancement of photoluminescence efficiency which has the peak around 1550‐nm wavelength was observed by growing InAs QDs on atomically controlled GaAs surfaces. This is due to the migration enhancement of InAs during thegrowth the QDs. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Quantum dot spin pure‐dephasing due to bulk magnons at low temperatures
Authors: Jacak Witold , Krasnyj Jurij , Jacak Lucjan
Published: December 2008

We demonstrate disappearance at 0 T = 0, and strong reduction at low temperatures, of pure‐dephasing of exciton spin located in a quantum dot (QD) embedded in a magnetic medium, e.g. in a diluted magnetic semiconductor. The off‐diagonal spin decoherence results due to hybridization of local QD exciton spin with magnons from surrounding crystal–we estimate the corresponding time‐scale and formulate a general rule for the scaling of dephasing time versus QD diameter derived within the Green function approach (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)