bluuebunny/crossref_metadata_2025_split huggingface dataset:
Synthesis and characterization of donor–bridge–acceptor alternating copolymers containing perylene diimide units and their application to photovoltaic cells
Authors: Yuan Mao‐Chuan , Su Ming‐Hsin , Chiu Mao‐Yuan , Wei Kung‐Hwa 
Published: February 2010

AbstractWe have used Suzuki coupling to prepare a series of alternating copolymers featuring coplanar cyclopentadithiophene and hole‐transporting carbazole units. We observed quenching in the photoluminescence spectra of our polymers after incorporating pendent electron‐deficient perylene diimide (PDI) moieties on the side chains, indicating more efficient photoinduced electron transfer. Electrochemical measurements revealed that the PDI‐containing copolymers displayed reasonable and sufficient offsets of the energy levels of their lowest unoccupied molecular orbitals for efficient charge dissociation. The performance of bulk heterojunction photovoltaic cells incorporating the copolymer/[6,6]‐phenyl‐C61‐butyric acid methyl ester blends (1:4, w/w) was optimized when the active layer had a thickness of 70 nm. The photocurrents of the devices were enhanced as a result of the presence of the PDI moieties, thereby leading to improved power conversion efficiencies. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 1298–1309, 2010
Synthesis and properties of crosslinked chiral nanoparticles via RAFT miniemulsion polymerization
Authors: Xu Wenliang , Cheng Zhenping , Zhang Lifen , Zhang Zhengbiao , Zhu Jian , Zhou Nianchen , Zhu Xiulin 
Published: February 2010

AbstractCrosslinked chiral nanoparticles were successfully synthesized via reversible addition‐fragmentation chain transfer (RAFT) miniemulsion polymerization of 6‐O‐p‐vinylbenzyl‐1,2:3,4‐di‐O‐isopropylidene‐D‐galactopyranose (VBPG) using linear poly(VBPG) as the macro‐RAFT agent. The polymerization of VBPG in the absence of crosslinker was first studied and the kinetic results showed that the molecular weights of the obtained poly(VBPG) increased linearly with the monomer conversion and was in good consistency with the corresponding theoretical ones while there remained a relative narrow polydispersity. The effect of the amount of crosslinker, divinylbenzene, on the nanoparticle size and chiral separation properties of the obtained nanoparticles were investigated in detail using four racemates ±‐3‐Amino‐1,2‐propanediol, D,L‐arabinose, D,L‐tartaric acid, and D,L‐mandelic acid. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 1324–1331, 2010
Flexible nanocrystalline‐titania/polyimide hybrids with high refractive index and excellent thermal dimensional stability
Authors: Liou Guey‐Sheng , Lin Po‐Han , Yen Hung‐Ju , Yu Yang‐Yen , Chen Wen‐Chang 
Published: February 2010

AbstractIn this study, a novel synthetic route was developed to prepare polyimide–nanocrystalline–titania hybrid optical films with a relatively high titania content (up to 50 wt %) and thickness (20–30 μm) from soluble polyimides containing hydroxyl groups. Two series of newly soluble polyimides were synthesized from the hydroxy‐substituted diamines with various commercial tetracarboxylic dianhydrides. The hydroxyl groups on the backbone of the polyimides could provide the organic–inorganic bonding and resulted in homogeneous hybrid solutions by controlling the mole ratio of titanium butoxide/hydroxyl group. AFM, SEM, TEM, and XRD results indicated the formation of well‐dispersed nanocrystalline‐titania. The flexible hybrid films could be successfully obtained and revealed relatively good surface planarity, thermal dimensional stability, tunable refractive index, and high optical transparency. A three‐layer antireflection coating based on the hybrid films was prepared and showed a reflectance of less than 0.5% in the visible range indicated its potential optical applications. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 1433–1440, 2010
A novel type of optically active helical polymers: Synthesis and characterization of poly(α,β‐unsaturated ketone)
Authors: Wu Shi , Yang Nianfa , Yang Liwen , Cao Jing , Liu Ji 
Published: February 2010

AbstractNew α,β‐unsaturated ketone monomers, menthyl vinyl ketone (MVK), and 1‐menthylbut‐3‐en‐2‐one (MBEK) were synthesized. The monomers were polymerized using butyllithium as an initiator. The polymer derived from MVK (poly‐MVK) had a tremendous specific optical rotation [α], which was as 32 times large as that of its monomer MVK. Poly‐MVK was confirmed to keep a prevailing helicity of backbone in solution by means of comparing the specific optical rotation and the CD spectra with that of MVK and the model compound such as ethyl menthyl ketone (EMK) and n‐hexyl menthyl ketone (n‐HMK). This conclusion was also confirmed by the fact that the specific optical rotation and the CD signal intensity of poly‐MBEK were not enough large due to backbone flexibility caused by the effective isolation of the main chain from the bulky menthyl. The excess value of one‐handed helicity of poly‐MVK decreased with the increase of polymerization temperature. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 1441–1448, 2010
Nucleation characteristics of the α/β compounded nucleating agents and their influences on crystallization behavior and mechanical properties of isotactic polypropylene
Authors: Zhao Shicheng , Xin Zhong 
Published: February 2010

AbstractNucleation characteristics of isotactic polypropylene (iPP) nucleated by the α/β compounded nucleating agents (NAs) were investigated by wide‐angle X‐ray scattering, differential scanning calorimetry and mechanical testing. The results showed that the nucleation effect of the α/β compounded NAs depends on not only nucleation efficiency (NE) of individual β and α NAs and their ratios but also the processing conditions, especially the cooling rates. The nucleating characteristics of the α/β compounded NAs can be illustrated by competitive nucleation. The NA with high NE played a leading role during iPP crystallization even at a low weight ratio and at different cooling rates. The stiffness and toughness of iPP can be simultaneously improved by using suitable compositions at the appropriate ratios. Finally, the nonisothermal crystallization kinetics of iPP nucleated with the α/β compounded NAs was described by Caze method and the crystallization activation energy of nucleated iPP was calculated by Kissinger equation. The result indicated that the crystal growth pattern of nucleated iPP was heterogeneous nucleation followed by three‐dimension spherical growth. © 2010 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 48: 653–665, 2010
Synthesis and comparative study of biodegradable poly(alkylene sebacate)s
Authors: Papageorgiou George Z. , Bikiaris Dimitrios N. , Achilias Dimitris S. , Nanaki Stavroula , Karagiannidis Nikitas 
Published: February 2010

AbstractNovel biodegradable polyesters, such as poly(ethylene sebacate) (PESeb), poly(propylene sebacate) (PPSeb), and poly(butylene sebacate) (PBSeb), were synthesized and studied with respect to melting behavior, crystallization kinetics, and enzymatic hydrolysis. PESeb and PPSeb showed multiple melting behavior. Wide angle X‐ray diffractometry measurements at various temperatures, standard, step‐scan, and high‐rate differential scanning calorimetry methods were applied to elucidate the appearance of multiple endotherms in heating scans, which was interpreted in the context of partial melting‐recrystallization and final melting. PBSeb did not show any multiple melting behavior but only a weak tendency for recrystallization on heating. The melting temperatures of PESeb, PPSeb, and PBSeb were measured equal to 78, 57, and 71 °C, respectively. The equilibrium melting points were estimated to be Tm° = 90.2, 69.9, and 77.4 °C for PESeb, PPSeb, and PBSeb, while the corresponding enthalpy of fusion values were found to be ΔHf = 170 ± 10, 140 ± 10, and 155 ± 10 J/g, respectively. The polyesters showed fast crystallization rates under both isothermal and nonisothermal conditions. Crystallization kinetics was thoroughly investigated using macrokinetic models and isoconversional analysis. Enzymatic hydrolysis rate in the presence of lipases Rhizopus delemar and Pseudomonas cepacia was found to be fast for PPSeb, whereas PESeb and PBSeb showed slow rates and comparable with those of PCL. © 2010 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 48: 672–686, 2010
Associations of tonsillar hypertrophy and snoring with history of wheezing in childhood
Authors: Kaditis Athanasios G. , Kalampouka Efthimia , Hatzinikolaou Souzana , Lianou Loukia , Papaefthimiou Maria , Gartagani‐Panagiotopoulou Polytimi , Zintzaras Elias , Chrousos George 
Published: February 2010

AbstractBackgroundReports in adults and children have correlated history of wheezing or asthma with the presence of obstructive sleep‐disordered breathing but the mechanism of this epidemiologic association is unknown. The goal of the present study was to examine whether tonsillar hypertophy can explain this association.MethodsChildren were recruited from the Emergency Department and the Pediatric Pulmonology Clinic. History of wheezing requiring treatment (explanatory variable) and snoring ≥1 night/week (outcome) were recorded and presence of tonsillar hypertrophy (outcome) was assessed.ResultsFour hundred forty‐two children were recruited (mean age: 7.6 ± 3.6 years) and 210 of them had history of wheezing. History of wheezing was significantly associated with the presence of tonsillar hypertrophy and snoring even after adjustment for age, gender, obesity, and passive smoking [odds ratio (95% confidence interval): 2.23 (1.37–3.63); P = 0.001 and 1.73 (1.12–2.67); P = 0.013, respectively]. When only children with tonsillar hypertrophy were considered (n = 92), history of wheezing was significantly related to the presence of snoring, whereas in subjects without tonsillar hypertrophy (n = 350) wheezing did not affect snoring [odds ratio: 2.76 (1.10–6.93); P = 0.031 and 1.49 (0.92–2.43); P = 0.107, respectively].ConclusionsChildren with history of wheezing have more frequently tonsillar hypertrophy than those without wheezing. Tonsillar hypertrophy may mediate at least in part the reported association between asthma and obstructive sleep‐disordered breathing in childhood. Pediatr Pulmonol. 2010; 45:275–280. © 2010 Wiley‐Liss, Inc.
Liver proteins as sensor of human malignancies and inflammation
Authors: Peracaula Rosa , Sarrats Ariadna , Rudd Pauline M. 
Published: February 2010

AbstractIn this review we would like to highlight the importance of acute‐phase proteins as sensor of diseases. Both acute‐phase protein levels and glycosylation have been reported to be altered in inflammation and other diseases including cancer. Factors that promote acute‐phase protein synthesis and enhance the expression of specific glycosyltransferases, such as sialyltransferases and fucosyltransferases, may be up‐regulated in some tumours and would explain the changes in acute‐phase protein levels and the specific N‐glycosylation modifications of some acute‐phase proteins in cancer. However, further studies are required to define the potential clinical application of these acute‐phase protein cancer‐specific modifications as possible cancer diagnostic or monitoring tools.
Structural investigation of transcriptional regulator HlyIIR: Influence of a disordered region on protein fold and dimerization
Authors: Kovalevskiy Oleg V. , Solonin Alexander S. , Antson Alfred A. 
Published: February 2010

AbstractB. cereus HlyIIR belongs to the TetR family of dimeric transcriptional regulators. Unlike other members of the TetR family, HlyIIR contains an insert between α‐helices α8 and α9, which is located at the subunit–subunit interface. N‐terminal segment of this insert (amino acids, Pro161–Ser169) forms a short α‐helix α8* that occupies a complementary cavity on the surface of the adjacent subunit, whereas the C‐terminal segment comprising 16 amino acids (Leu170–Glu185) is disordered. To understand whether this disordered segment is important for protein's function, we determined crystal structures of two engineered HlyIIR proteins where this segment was either substituted by a seven‐residue flexible Ser‐Gly linker or replaced by a cleavable peptide containing proteolytic sites at both ends. Unexpectedly, alteration or proteolytic removal of the disordered segment resulted in changes in protein's conformation and in a remarkable rearrangement at the subunit–subunit interface. X‐ray structures of the two engineered proteins revealed an unusual plasticity at the dimerization interface of HlyIIR enabling it to form dimers stabilized by different sets of interactions. Structural comparison indicates that in spite of the flexible nature of the disordered segment, it is critical for maintaining the native structure as it influences the position of α8*. The data demonstrate how disordered loops on protein surfaces may affect folding and subunit–subunit interactions. Proteins 2010. © 2010 Wiley‐Liss, Inc.
Selective cleavage of an azaGly peptide bond by copper(II). Long‐range effect of histidine residue
Authors: Mhidia Reda , Melnyk Oleg 
Published: February 2010

AbstractSeveral reports have highlighted the interest of replacing Gly, a frequent amino acid within bioactive peptides, by azaGly (Agly) to improve their stability, activity or for the design of prodrugs. Because metal catalysis is increasingly used for tailoring peptide molecules, we have studied the stability of Agly peptides in the presence of metal ions. In this study, we show that Cu(II), unlike other metal ions such as Fe(II), Fe(III), Pd(II), or Pt(II), induces the cleavage of Agly peptides at room temperature and pH 7.3. The cleavage occurred in the absence of an anchoring His residue within the peptide but it was accelerated when this amino acid was present in the sequence. The influence of His residue on the cleavage rate was minimal when His and Agly were adjacent, whereas large effects were observed for distant His residues. The reaction between Cu(II) and Agly peptides induced the formation of Cu(I) species, which could be detected using bicinchoninic acid as a probe. The nature of products formed in this reaction allowed suggesting a mechanism for the Cu(II)‐induced cleavage of Agly peptides. Copyright © 2010 European Peptide Society and John Wiley & Sons, Ltd.
Problem‐based learning approach to application of statistical experimentation
Authors: Goh T. N. , Lam S. W. 
Published: February 2010

AbstractIn product development, statistical experimentation techniques can help to improve product quality so as to meet or even exceed customers' requirements. To integrate proper statistical techniques effectively and sustainably into new product development and innovation processes, it is important to train product development engineers who are usually experts in their respective engineering domain. In this paper, a problem‐based learning approach integrated within a Design for Six Sigma (DFSS) training program is described. It is illustrated that instead of relying on ad hoc implementation, statistical experimentation introduced through the DFSS methodology would enable product development engineers to appreciate its usefulness within a broader framework. Copyright © 2010 John Wiley & Sons, Ltd.
On monitoring process variance with individual observations
Authors: Yeh Arthur B. , Huwang Longcheen , McGrath Richard N. , Zhang Zhe 
Published: February 2010

AbstractThis paper proposes a new control chart to effectively monitor the decrease in variance of a normal process when only individual observations are available. The idea of the new control chart, which is called the exponentially weighted mean squared inverse error (EWMSI) chart, stems from the exponentially weighted mean squared error (EWMS) chart of MacGregor and Harris (J. Qual. Technol. 1993; 25(2):106–118). Simulation studies and an example demonstrate that the lower‐sided EWMSI chart is superior to the lower‐sided EWMS chart and the lower‐sided modified EWMS (M‐EWMS) chart of Huwang et al. (Nav. Res. Logist. 2009; 56(7):659–668) in detecting a decrease in process variance. Furthermore, the combination of a lower‐sided EWMSI chart and an upper‐sided EWMS chart is shown to outperform the two‐sided EWMS chart and the two‐sided M‐EWMS chart in monitoring the overall changes in process variance. Copyright © 2010 John Wiley & Sons, Ltd.
Guidelines for the placement of fiducial points in image‐guided neurosurgery
Authors: Wang Manning , Song Zhijian 
Published: February 2010

AbstractBackgroundPoint‐pair registration is widely used to register the patient and the image space in image‐guided neurosurgery. The registration accuracy at the target point is influenced by the distribution of the fiducial points, and it is not always easy to achieve a good distribution in clinical practice.MethodsWe propose one original configuration and three variants of the distribution of the fiducial points, in which each fiducial point has a definite position on the head surface. These configurations are conceived by considering both the theoretical value of the target registration error (TRE) and practical constraints on the positioning of the fiducial points. These configurations can guide the surgeon to place fiducial points directly onto the patient's head.ResultsExperiments with real clinical data showed that when using the original configuration, the TRE in the whole skull was < 2 mm and the TRE in the whole brain was < 1.5 mm if the fiducial registration error was 2.5 mm. When using variants of the original configuration, small TRE can also be achieved in the corresponding surgical field.ConclusionsThis study provides an easy‐to‐use approach to achieving good distribution of fiducial points in image‐guided neurosurgery. Copyright © 2010 John Wiley & Sons, Ltd.
Downstream environmental effects of dam operations: Changes in habitat quality for native fish species
Authors: García Alex , Jorde Klaus , Habit Evelyn , Caamaño Diego , Parra Oscar 
Published: February 2010

AbstractHydropeaking dam operation and water extractions for irrigation have been broadly stated as alterations to natural flow regimes, which have also been noticed in the Biobío Watershed, in Central Chile, since 1996. In the Biobío River, most of native fish species are endemic and very little is known about them. Their ecological and social values have never been estimated, and there is lack of information about their habitat preferences. Furthermore, changes on fish habitat availability due to natural and/or man‐made causes have not been evaluated. In this study, eight native fish species, in a representative reach of the Biobío River, were studied and their preferred habitats were surveyed and characterized. A hydrodynamic model was built and linked to the fish habitat simulation model CASiMiR. Fuzzy rules and fuzzy sets were developed for describing habitat preference of the native fish species. CASiMiR was then used to simulate how physical habitat conditions vary due to flow control (i.e. upstream dams). Results show how overall habitat quality, expressed as weighted usable area (WUA) and hydraulic habitat suitability (HHS), changes and fluctuates due to the dam operation and how the daily hydropeaking is influencing quantity, quality and location of different habitats. The study suggests that the analysed fish are highly susceptible to flow control, as dams are currently operated, and fish habitat improvement suggestions are proposed. Copyright © 2010 John Wiley & Sons, Ltd.
Automatic detection and replacement of syntactic constructs causing shift/reduce conflicts
Authors: Kramer Thomas R. 
Published: February 2010

AbstractA method is described for repairing some shift/reduce conflicts caused by limited lookahead in LALR(1) parsers such as those built by bison. Also, six types of Extended BNF (EBNF) construct are identified that cause a shift/reduce conflict when a Yet Another Compiler Compiler (YACC) file translated directly from EBNF is processed by bison. For each type, a replacement EBNF construct is described representing the same grammar and causing no shift/reduce conflict when its YACC equivalent is processed by bison. Algorithms are given for identifying instances of each type and transforming them into their replacements. The algorithms are implemented in an automatic parser builder that builds parsers for subsets of the DMIS language. The parser builder reads an EBNF file and writes C++ classes, a YACC file, and a Lex file, which are then processed to build a parser. The parsers build a parse tree using the C++ classes. The EBNF for DMIS is written in natural terms so that natural C++ classes are generated. However, if translated directly into YACC, the natural EBNF leads to 22 shift/reduce conflicts that fall into the six types. The parser builder recognizes the six constructs and replaces them automatically before generating YACC. The YACC that is generated parses in terms of unnatural constructs while building a parse tree using natural C++ classes. The six types of construct may occur in any statement‐based language that uses a minor separator, such as a comma; hence knowing how to recognize and replace them may be broadly useful. Published in 2010 by John Wiley & Sons, Ltd.
Growth of fetal lean mass and fetal fat mass in gestational diabetes
Authors: Nobile de Santis M. S. , Taricco E. , Radaelli T. , Spada E. , Rigano S. , Ferrazzi E. , Milani S. , Cetin I. 
Published: February 2010

AbstractObjectivesThis study was carried out to investigate growth indicators of fetal lean mass and fat mass in the second half of the gestational period in pregnancies complicated by gestational diabetes mellitus (GDM) in comparison to normal control pregnancies.MethodsForty‐three control and 171 GDM pregnancies were followed longitudinally by ultrasound examinations, measuring both traditional biometric parameters and six non‐traditional parameters for the evaluation of lean and fat mass. A mixed linear model derived from the log‐Count function was used to model fetal growth and to make comparisons between groups. Factor analysis was used to evaluate the associations between gestational diabetes and fetal size and fetal fat/lean mass ratios.ResultsA total of 506 scans were obtained in the 214 pregnancies, a mean of 2.4 scans per pregnancy (range 2–5). Maternal age, prepregnancy weight and body mass index were significantly higher in GDM pregnancies. Fetuses of GDM pregnancies showed greater growth, at the same gestational age, for each lean and fat non‐traditional parameter, having a significantly greater amount of total tissue mass and a higher fat mass/lean mass ratio, independent of gestational age, in comparison to control pregnancies.ConclusionsA non‐invasive, repeatable evaluation of fetal body composition in utero could represent a useful method for the early detection of growth abnormalities and for direct estimation of the fetal metabolic status. Copyright © 2010 ISUOG. Published by John Wiley & Sons, Ltd.