bluuebunny/crossref_metadata_2025_split huggingface dataset:
Metal ion attachment to the matrix meso‐tetrakis(pentafluorophenyl)porphyrin, related matrices and analytes: an experimental and theoretical study
Authors: van Kampen Jeroen J. A. , Luider Theo M. , Ruttink Paul J. A. , Burgers Peter C. 
Published: June 2009

AbstractIn a previous study [van Kampen et al. Analytical Chemistry 2006; 78: 5403], we found that meso‐tetrakis (pentafluorophenyl)porphyrin (F20TPP), in combination with lithium salts, provides an efficient matrix to cationize small molecules by Li+ attachment and that this combination can be successfully applied to the quantitative analysis of drugs, such as antiretroviral compounds using matrix‐assisted laser desorption ionization in conjunction with a time‐of‐flight analyzer (MALDI–TOF). In the present study, we further explore the mechanism of metal ion attachment to F20TPP and analytes by MALDI–FTMS(/MS). To this end, we have studied the interaction of F20TPP and analytes with various mono‐, di‐ and trivalent metal ions (Li+, Na+, K+, Rb+, Cs+, Co2+, Cu2+, Zn2+, Fe2+, Fe3+ and Ga3+). For the alkali cations, we find that F20TPP forms complexes only with Li+ and Na+; in addition, model analyte molecules such as poly(ethyleneglycol)s, mixed with F20TPP and the alkali cations, also only form Li+ and Na+ adducts. This contrasts sharply with the commonly used matrix 2,5‐dihydroxybenzoic acid, where analytes are most efficiently cationized by Na+ or K+. Reasons for this difference are delineated. Ab initio calculations on porphyrin itself reveal that even the smallest alkali cation, Li+, does not fit in the porphyrin cavity, but lies on top of it, pushing the 21H and 23 H hydrogen atoms out of and below the plane with concomitant bending of the porphyrin skeleton in the opposite direction, i.e. toward the cation. Thus, the Li+ ion is not effectively sequestered and is in fact exposed and thus accessible for donation to analyte molecules. Interaction of F20TPP with di‐ and trivalent metal ions leads to protoporphyrin–metal ions, where the metal ion is captured within the protoporphyrin dianion cavity. The most intense signal is obtained when F20TPP is reacted with CuCl2 and then subjected to laser ablation. This method presents an easy general route to study the metal containing protoporphyrin molecules, which could all act as potential MALDI matrices. Copyright © 2009 John Wiley & Sons, Ltd.
International ICT policy frameworks: A multi‐country case study of success in interactivity, mobility, convertibility, connectivity, ubiquity, and globalization
Authors: Naidoo Jeff 
Published: June 2009

AbstractVarious countries have developed broad ICT policy frameworks that focus on enabling the knowledge economy through improving diffusion mechanisms and enhancing uptake conditions. In many cases these policies have failed to promote a forward‐looking information society or deliver anticipated economic growth and social development (Mui and Chun, 2004). However, Finland and Singapore, classified by the Central Intelligence Agency World Factbook as advanced economies (CIA, 2008), have shown exceptional leadership in developing and executing robust ICT policy frameworks that have effectively supported their successful transformations to high‐growth knowledge economies, thereby promoting prosperity, economic growth, and community cohesion within these regions. This study aims to analyze the unique characteristics of Finland and Singapore's national ICT policy frameworks that have contributed to their interactivity, mobility, convertibility, connectivity, ubiquity, and globalization. As it does so, it will identify several critical success factors that have shaped progress in these settings. Identification of these success factors will help policy makers and IT practitioners as they devise meaningful policies.
Splenectomy in two children with autoimmune lymphoproliferative syndrome and massive splenomegaly
Authors: Glerup Mia , Thelle Thomas , Grønbæk Kirsten , Hasle Henrik 
Published: June 2009

AbstractTreatment of patients with ALPS has varied but presently there is no consensus about the optimal therapy. Splenectomy is an option but data regarding the postsplenectomy outcome in pediatric ALPS patients remain very limited. We present two children who suffered from anemia and physical discomfort from the large spleen. Both patients underwent uneventful splenectomy and experienced significant improvement in cytopenia, daily activity and well‐being. Furthermore the youngest patient showed a significant catch‐up growth. We conclude that in selected patients with marked splenomegaly and ALPS, splenectomy may be considered a treatment option. Pediatr Blood Cancer 2009;53:1124–1126. © 2009 Wiley‐Liss, Inc.
Flow cytometric chemosensitivity assay as a predictive tool of early clinical response in acute lymphoblastic leukemia
Authors: Galderisi Faith , Stork Linda , Li Ju , Mori Motomi , Mongoue‐Tchokote Solange , Huang James 
Published: June 2009

AbstractBackgroundResidual disease or rapidity of response to induction therapy is among the most powerful predictors of outcome in pediatric acute lymphoblastic leukemia (ALL).MethodUtilizing a multiparameter flow cytometric chemosensitivity assay (FCCA), we studied the relationship between in vitro drug sensitivity of diagnostic leukemic blasts from 30 children with ALL and rapidity of response to induction therapy. We also analyzed the in vitro drug sensitivity of de novo leukemic blasts among various clinical subsets.ResultsCompared to rapid early responders (RERs), slow early responders (SERs) had a significantly greater in vitro drug resistance to dexamethasone (DEX; P = 0.04) and prednisone (P = 0.05). The studies with all other drugs showed a non‐significant trend with the SER having a higher in vitro drug resistance compared to the RER. Risk group stratified analyses indicated that in vitro resistance to asparaginase (ASP), DEX, and vincristine (VCR) were each significantly related to having very high risk ALL. Additionally, a significantly higher in vitro drug resistance to ASP and VCR was associated with unfavorable lymphoblast genetics and ultimate relapse.ConclusionOur data indicate that this FCCA is a potentially simple and rapid method to detect inherent resistance to initial ALL therapy very early in induction, thus allowing for treatment modification shortly thereafter. Pediatr Blood Cancer 2009;53:543–550. © 2009 Wiley‐Liss, Inc.
Compound heterozygous HAX1 mutations in a Swedish patient with severe congenital neutropenia and no neurodevelopmental abnormalities
Authors: Carlsson Göran , Elinder Göran , Malmgren Helena , Trebinska Alicja , Grzybowska Ewa , Dahl Niklas , Nordenskjöld Magnus , Fadeel Bengt 
Published: June 2009

AbstractKostmann disease or severe congenital neutropenia (SCN) is an autosomal recessive disorder of neutrophil production. Homozygous HAX1 mutations were recently identified in SCN patients belonging to the original family in northern Sweden described by Kostmann. Moreover, recent studies have suggested an association between neurological dysfunction and HAX1 deficiency. Here we describe a patient with a compound heterozygous HAX1 mutation consisting of a nonsense mutation (c.568C > T, p.Glu190X) and a frame‐shift mutation (c.91delG, p.Glu31LysfsX54) resulting in a premature stop codon. The patient has a history of neutropenia and a propensity for infections, but has shown no signs of neurodevelopmental abnormalities. Pediatr Blood Cancer 2009;53:1143–1146. © 2009 Wiley‐Liss, Inc.
Miscarriage after invasive prenatal diagnostic procedures: how much risk our pregnant women are willing to take?
Authors: Chan Yiu Man , Sahota Daljit Singh , Chan Oi Ka , Leung Tak Yeung , Lau Tze Kin 
Published: June 2009

AbstractObjectivesTo elicit the level of risk of prenatal diagnostic procedure‐related miscarriage that Chinese pregnant women were willing to accept.MethodsAn interviewer‐administered survey was conducted on 276 women who presented to the University Obstetric Unit. Using the standard gamble approach, subjects were asked to choose between a screening test with a 90% detection rate and a diagnostic test which is definitive but carries a finite risk of abortion. This probability of abortion was varied until the subject was indifferent between the two choices, and the value was called the utility score.ResultsWhen compared with a screening test with 90% detection rate, the median utility score was 0.989 (IQR: 0.970–0.999). The median risk of abortion below which the subjects would rather opt for an invasive test instead of a screening test was 1.1%. The percentage of patients who could accept a procedure‐related miscarriage risk of 0.2, 0.5, 1 and 2% were 76, 67, 59.8 and 38.4%, respectively.ConclusionsPregnant Chinese women agreed to trade a definitive chromosomal diagnostic test from a highly effective screening test with a small risk of undiagnosed aneuploidy provided that the procedure‐related miscarriage risk was 1.1% or lower. Copyright © 2009 John Wiley & Sons, Ltd.
Maternal serum angiopoietin‐2 at 11 to 13 weeks of gestation in hypertensive disorders of pregnancy
Authors: Akolekar Ranjit , Casagrandi Davide , Skyfta Evdoxia , Ahmed Abubaker Abdalla , Nicolaides Kypros H. 
Published: June 2009

AbstractObjectiveIn women with preeclampsia (PE), the serum concentration of the growth factor angiopoietin‐2 (Ang‐2) is significantly lower than in unaffected controls. The objective of this study is to determine if the decrease in serum Ang‐2 is evident from the first trimester of pregnancy before the clinical onset of PE.MethodsSerum Ang‐2 and uterine artery pulsatility index (PI) were measured at 11 to 13 weeks in 126 pregnancies that subsequently developed PE, 88 cases that developed gestational hypertension (GH) and 214 unaffected controls.ResultsMaternal serum Ang‐2 in the PE group [0.96 multiple of the median (MoM)] and in GH (1.12 MoM) was not significantly different from the unaffected group (1.07 MoM). Uterine artery PI was significantly higher in the PE group (1.32 MoM) but not in GH (1.11 MoM) compared to the unaffected group (1.05 MoM).ConclusionIn pregnancies that develop PE there is Doppler evidence of impaired placentation from the first trimester of pregnancy. However, the impaired placentation is not reflected in altered maternal serum levels of Ang‐2. Copyright © 2009 John Wiley & Sons, Ltd.
A comparison of teachers' and school psychologists' perceptions of the importance of CHC abilities in the classroom
Authors: Fiorello Catherine A. , Thurman S. Kenneth , Zavertnik Jennifer , Sher Robert , Coleman Schehera 
Published: June 2009

AbstractThe broad cognitive abilities defined by the Cattell–Horn–Carroll (CHC) theory have been shown to predict school achievement. However, the ecological validity of these constructs has not been studied in classroom settings. This study compares ratings by a sample of teachers (n= 53) and school psychologists (n= 86) of the importance of the CHC cognitive abilities in the classroom. The scale demonstrated adequate reliability (total scale α = .93, median α = .74), although evidence of construct validity varied between teachers and school psychologists. Both teachers and school psychologists rated quantitative ability, crystallized knowledge, and fluid reasoning as most important to school success. However, school psychologists rated short‐term memory and quantitative ability as more important than did the teachers. Importance of these differences for consultation is discussed. © 2009 Wiley Periodicals, Inc.
Confirmatory factor analysis of the KABC‐II in preschool children
Authors: Morgan Kimberly E. , Rothlisberg Barbara A. , McIntosh David E. , Hunt Madeline S. 
Published: June 2009

AbstractThe present study assessed the Kaufman Assessment Battery for Children, Second Edition (KABC‐II) in relation to the synthesized Cattell–Horn–Carroll (CHC) theory of intelligence with a preschool sample. Participants were 200 preschool children between four and five years of age. A confirmatory factor analysis (CFA) was conducted, and different variations of the CHC model were examined to determine which provided the best representation of the proposed underlying CHC constructs tested by the KABC‐II. The models included one similar to Spearman's g, a contemporary two‐stratum model consisting of fluid and crystallized intelligence (Gf‐Gc model), and a synthesized CHC broad factor +g model. The last was the empirically validated theory of interest in this study. Results of the CFA revealed that the broad factor +g CHC model was the best overall design to explain KABC‐II results. © 2009 Wiley Periodicals, Inc.
Synthesis and characterization of indeno[1,2‐b]fluorene‐based white light‐emitting copolymer
Authors: Jeong Eunjae , Kim Sun Hee , Jung In Hwan , Xia Yangjun , Lee Kwanghee , Suh Hongsuk , Shim Hong‐Ku , Woo Han Young 
Published: June 2009

AbstractAn indenofluorene‐based copolymer containing blue‐, green‐, and red light‐emitting moieties was synthesized by Suzuki polymerization and examined for application in white organic light‐emitting diodes (WOLEDs). Tetraoctylindenofluorene (IF), 2,1,3‐benzothiadiazole (BT), and 4,7‐bis(2‐thienyl)‐2,1,3‐benzothiadiazole (DBT) derivatives were used as the blue‐, green‐, and red‐light emitting structures, respectively. The number‐average molecular weight of the polymer was determined to be 25,900 g/mol with a polydispersity index of 2.02. The polymer was thermally stable (Td = ∼398 °C) and quite soluble in common organic solvents, forming an optical‐quality film by spin casting. The EL characteristics were fine‐tuned from the single copolymer through incomplete fluorescence energy transfer by adjusting the composition of the red/green/blue units in the copolymer. The EL device using the indenofluorene‐based copolymer containing 0.01 mol % BT and 0.02 mol % DBT units (PIF‐BT01‐DBT02) showed a maximum brightness of 4088 cd/m2 at 8 V and a maximum current efficiency of 0.36 cd/A with Commission Internationale de L'Eclairage (CIE) coordinates of (0.34, 0.32). The EL emission of PIF‐BT01‐DBT02 was stable with respect to changes in voltage. The color emitted was dependent on the thickness of the active polymer layer; layer (∼60 nm) too thin was unsuitable for realizing WOLED via energy transfer. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 3467–3479, 2009
Ethylenebis(5‐chlorosalicylideneiminato)vanadium dichloride immobilized on MgCl2‐based supports as a highly effective precursor for ethylene polymerization
Authors: Białek Marzena , Pietruszka Anna 
Published: June 2009

AbstractEthylenebis(5‐chlorosalicylideneiminato)vanadium dichloride supported on MgCl2(THF)2 or on the same carrier modified by EtnAlCl3−n, where n = 1–3, was used in ethylene polymerization in the presence of MAO or a common alkylaluminium compounds as a cocatalyst. The support type alter vanadium loading and also change the characteristic of the catalytic active sites. Et2AlCl is the best activator for a catalyst which has been immobilized on a nonmodified support, whereas the systems which contain a carrier which has been modified by an organoaluminium compound reveal the highest activity in conjunction with MAO. That difference, together with different temperature effects on polymerization efficiency (i.e., decrease and increase of catalytic activity for increasing temperatures, respectively) suggest the formation of different types of active sites in the catalytic systems supported on modified and nonmodified magnesium carrier. However, all supported precatalysts possess a long lifetime, still being active towards ethylene polymerization after 2 h. All the systems yield wide MWD polyethylene, while bimodal MWD is found for some part of analyzed samples. Polyethylene with bimodal particle size distribution is formed with the system which contain modified carriers at higher temperatures. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 3480–3489, 2009
Syntheses, characterization, and properties of multiblock copolymers consisting of polyisobutylene and poly(L‐lactide) segments
Authors: Ojha Umaprasana , Kulkarni Pallavi , Singh Jagdeep , Faust Rudolf 
Published: June 2009

AbstractThe syntheses of {‐poly(L‐lactide) (PLLA)‐b‐polyisobutylene (PIB)‐}n multiblock copolymers were accomplished for the first time by chain extension of PLLA‐b‐PIB‐b‐PLLA triblock copolymers. Well‐defined PLLA‐b‐PIB‐b‐PLLA triblock copolymers with predictable Mns, low PDIs (1.10–1.18) and excellent blocking efficiencies were prepared by anionic ring‐opening polymerizations of L‐lactide initiated with hydroxyallyl telechelic PIB (HO‐Allyl‐PIB‐Allyl‐OH) in toluene at 110 °C. The triblock copolymers were successfully chain extended with 4,4′‐methylenebis(phenylisocyanate) (MDI) to obtain the multiblock copolymers with good gravimetric yields of ∼86 to 96%. The chain‐extended polymers were soluble in a range of common organic solvents. The block copolymers showed two glass transition temperatures in differential scanning calorimetric analysis for the PIB and PLLA blocks indicating microphase separation, which was supported by atomic force microscopy images. The as‐synthesized compression molded multiblock copolymers exhibited tensile strengths in the range of 8–24 MPa with elongations at break in the range of 2.5–400%. The static and dynamic mechanical properties showed a strong dependence on the relative PLLA content in the copolymer. The dynamic mechanical analysis also indicated microphase separation at higher PLLA compositions. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 3490–3505, 2009
Synthesis and properties of conjugated polymers containing 3,9‐ and 2,9‐linked carbazole units in the main chain
Authors: Tamura Kosaku , Shiotsuki Masashi , Kobayashi Norihisa , Masuda Toshio , Sanda Fumio 
Published: June 2009

AbstractNovel conjugated polymers containing 3,9‐ or 2,9‐linked carbazole units in the main chain were synthesized by the polycondensation of ethynyl‐ and iodo‐substituted 9‐arylenecarbazolylene monomers, and their optical and electrical properties were studied. Polymers with weight‐average molecular weights of 3400–12,000 were obtained in 76–99% yields by the Sonogashira coupling polycondensation in piperidine or tetrahydrofuran (THF)/piperidine at 30 °C for 48 h. All the 3,9‐linked polymers absorbed light around 300 nm. The para‐phenylene‐linked polymer also absorbed light around 350 nm, while meta‐phenylene‐linked one did not. The 3,9‐linked polymers absorbed light at a wavelength longer than the 2,9‐linked one. The polymers emitted blue fluorescence with high quantum yields (0.21–0.78) upon excitation at the absorption maxima. The polymers were oxidized around 0.6 V, and reduced around 0.5 V. Poly(1) showed the dark conductivity of 3.7 × 10−11 S/cm (103 V/cm). © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 3506–3517, 2009
Supramacromolecular self‐assembly: Chain extension, star and block polymers via pseudorotaxane formation from well‐defined end‐functionalized polymers
Authors: Gibson Harry W. , Farcas Aurica , Jones Jason W. , Ge Zhongxin , Huang Feihe , Vergne Matthew , Hercules David M. 
Published: June 2009

AbstractDibenzo‐24‐crown‐8‐terminated polystyrene (5) was chain extended to “dimeric” 8 by pseudorotaxane formation with a ditopic guest, α,ω‐bis[p‐(N‐benzylammoniomethyl)phenoxy]heptane bis(hexafluorophosphate) (7). The three‐armed star polymer 11 was similarly formed by complexation of the dibenzo‐24‐crown‐8‐terminated polystyrene (5) with a tritopic secondary ammonium salt, 1,3,5‐tris[p‐(benzylammoniomethyl)phenyl]benzene tris(hexafluorophosphate) (10). Another three‐armed star polymer 13 was self‐assembled from dibenzo‐24‐crown‐8‐terminated polystyrene (5) and a tetratopic paraquat compound, 1,2,4,5‐tetrakis{p‐N‐[(N′‐methyl‐4,4′‐bipyridinium)methylphenyl]}benzene octakis(hexafluorophosphate) (12). The above chain extension and star polymer formation processes seemed to be cooperative; that is, the second and third complexation steps proceed with stepwise higher efficiencies than statistically expected. Dibenzo‐24‐crown‐8‐terminated polystyrene (5) was chain extended with secondary ammonium terminated polystyrene 14, forming 16, and also self‐assembled with a secondary ammonium ion terminated polyisoprene 15 to form supramolecular block copolymer 17. These processes were examined by NMR, mass spectrometry and viscometery. Thus, although binding in these systems is not particularly strong (association constants <104 M−1), these examples provide proof‐of‐principle that pseudorotaxane formation is a viable concept for chain extension and self‐assembly of novel types of block copolymers and star polymers. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 3518–3543, 2009
Sequential thiol‐ene/thiol‐ene and thiol‐ene/thiol‐yne reactions as a route to well‐defined mono and bis end‐functionalized poly(N‐isopropylacrylamide)
Authors: Yu Bing , Chan Justin W. , Hoyle Charles E. , Lowe Andrew B. 
Published: June 2009

AbstractSequential thiol‐ene/thiol‐ene and thiol‐ene/thiol‐yne reactions have been used as a facile and quantitative method for modifying end‐groups on an N‐isopropylacrylamide (NIPAm) homopolymer. A well‐defined precursor of polyNIPAm (PNIPAm) was prepared via reversible addition‐fragmentation chain transfer (RAFT) polymerization in DMF at 70 °C using the 1‐cyano‐1‐methylethyl dithiobenzoate/2,2′‐azobis(2‐methylpropionitrile) chain transfer agent/initiator combination yielding a homopolymer with an absolute molecular weight of 5880 and polydispersity index of 1.18. The dithiobenzoate end‐groups were modified in a one‐pot process via primary amine cleavage followed by phosphine‐mediated nucleophilic thiol‐ene click reactions with either allyl methacrylate or propargyl acrylate yielding ene and yne terminal PNIPAm homopolymers quantitatively. The ene and yne groups were then modified, quantitatively as determined by 1H NMR spectroscopy, via radical thiol‐ene and radical thiol‐yne reactions with three representative commercially available thiols yielding the mono and bis end functional NIPAm homopolymers. This is the first time such sequential thiol‐ene/thiol‐ene and thiol‐ene/thiol‐yne reactions have been used in polymer synthesis/end‐group modification. The lower critical solution temperatures (LCST) were then determined for all PNIPAm homopolymers using a combination of optical measurements and dynamic light scattering. It is shown that the LCST varies depending on the chemical nature of the end‐groups with measured values lying in the range 26–35 °C. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 3544–3557, 2009