bluuebunny/crossref_metadata_2025_split huggingface dataset:
A method for deriving a future temporal spectrum of heavy precipitation on the basis of weather patterns in low mountain ranges
Authors: Franke Johannes , Bernhofer Christian 
Published: June 2009

AbstractA weather‐pattern‐based multiple regression model to derive future possible changes in the level of the higher temporal resolution spectrum of heavy precipitation has been developed. The temporal spectrum was described using statistical precipitation amounts as a function of the event's duration (1–24 h) and return period (once in 5 yr to once in 100 yr). The principle of the method consists in projecting a statistical relationship between the parameters of a transformed Gumbel distribution (theoretical extreme value distribution) and the distribution of classes of objective weather patterns to time slices in the near future of climate. Changes in distribution parameters were constructed in the model from changes in the distribution of weather patterns. Possible change signals were calculated for the catchment of the Weißeritz River (Ore Mountains, Germany) for the time slices centred around 2025 (2011–2040) and 2050 (2036–2065) as changes versus the reanalyses of the reference period 1961–2000 (May–September). For the climate conditions to be expected in the near future (IPCC A1B scenario), increases in the amounts of heavy precipitation, i.e. decreases in the return periods of equal amounts of heavy precipitation from the reference period, were obtained for the entire temporal spectrum covered by this paper. Overall, the change signals derived on the basis of a concept of weather patterns seem plausible because they represent a possible continuation of the already observed increase in frequency and intensification of events of heavy precipitation in the extended study area. Copyright © 2009 Royal Meteorological Society
Use of picosecond infrared laser for micromanipulation of early mammalian embryos
Authors: Karmenyan Artashes V. , Shakhbazyan Avetik K. , Sviridova‐Chailakhyan Tatiana A. , Krivokharchenko Alexander S. , Chiou Arthur E. , Chailakhyan Levon M. 
Published: June 2009

AbstractA high repetition rate (80 MHz) picosecond pulse (∼2 psec) infrared laser was used for the inactivation (functional enucleation) of oocytes and two‐cell mouse embryos and also for the fusion of blastomeres of two‐cell mouse embryos. The laser inactivation of both blastomeres of two‐cell mouse embryos by irradiation of nucleoli completely blocked further development of the embryo. The inactivation of one blastomere, however, did not affect the ability of the second intact blastomere to develop into a blastocyst after treatment. Laser inactivation of oocytes at Metaphase II (MII) stage and parthenogenetically activated pronuclear oocytes also completely blocked their ability for further development. Suitable doses of irradiation in cytoplasm region did not affect the ability of embryos and activated oocytes to development. The efficiency of laser induced fusion for blastomeres of two‐cell embryos was 66.7% and all the tetraploid embryos developed successfully into blastocysts in culture. Our results demonstrate unique opportunities of the applications of a suitable infrared periodic pulse laser as a universal microsurgery tool for individual living cells. Mol. Reprod. Dev. 76: 975–983, 2009. © 2009 Wiley‐Liss, Inc.
Retrieval of rhesus monkey (Macaca mulatta) oocytes by ultrasound‐guided needle aspiration: Problems and solutions
Authors: Rodriguez Nancy A. , Si Wei , Emmi Adelina M. , Layman Lawrence C. , Eroglu Ali 
Published: June 2009

AbstractOocytes of nonhuman primates such as rhesus monkeys are excellent models for diverse studies on developmental biology, epigenetics, human reproduction, and assisted reproductive technologies, as well as on transgenics. Such studies require numerous oocytes that can be retrieved after controlled ovarian stimulation. Currently, most primate centers use laparoscopic aspiration or laparotomy followed by aspiration to collect rhesus oocytes, although the ultrasound‐guided needle aspiration is more advantageous due to reduced infection risk, less injury, and a shorter recovery period. Yet, some initial difficulties associated with the ultrasound‐guided needle aspiration limit its broader application. The objective of the present study was to address these obstacles. By presenting practical solutions to the initial difficulties, results from our study show that it is possible to collect a mean number of 38 ± 10 rhesus oocytes per hormonally stimulated female. These results compare favorably to the average number of rhesus oocytes collected using the laparoscopic approach and suggest that when initial obstacles are overcome, the ultrasound‐guided oocyte retrieval represents a good alternative to more invasive approaches. Mol. Reprod. Dev. 76: 890–896, 2009. © 2009 Wiley‐Liss, Inc.
Gastrointestinal stromal tumors (GIST) in children and adolescents: A comprehensive review of the current literature
Authors: Benesch Martin , Wardelmann Eva , Ferrari Andrea , Brennan Bernadette , Verschuur Arnauld 
Published: June 2009

AbstractStandards for the management of gastrointestinal stromal tumors (GIST) in children do presently not exist. Thus a systematic review and summary of the current literature was conducted serving as a basis for the further development of optimal management strategies for childhood GIST within a cooperative network. Presently 21 cases with familial GIST, and more than 100 pediatric cases each with Carney triad or sporadic GIST have been published so far. An international prospective registration based on national registries has recently started to acquire more clinical and molecular data and to develop appropriate management strategies for children and adolescents with GIST. Pediatr Blood Cancer 2009; 53:1171–1179. © 2009 Wiley‐Liss, Inc.
Oxidative stress and executive function in children receiving chemotherapy for acute lymphoblastic leukemia
Authors: Caron Joshua E. , Krull Kevin R. , Hockenberry Marilyn , Jain Neelam , Kaemingk Kris , Moore Ida M. 
Published: June 2009

AbstractBackgroundNeurocognitive sequelae following treatment for pediatric acute lymphoblastic leukemia (ALL) has been reported in a significant proportion of survivors, including those treated only with chemotherapy. Early identification of children “at risk” for neurocognitive problems is not yet reliable. Biomarkers of oxidative stress (e.g., oxidated phosphatidylcholine) in cerebral spinal fluid (CSF) have been correlated with intensity of methotrexate (MTX) treatment, suggesting an association with acute central nervous system toxicity.ProcedureThis study examined the association between oxidized CSF phospholipids and executive functions throughout chemotherapy. Measures of oxidative stress and executive functions were examined in 88 children newly diagnosed with ALL. The children were followed over 3 years with neurocognitive testing and parent ratings of executive functions.ResultsResults demonstrated an association between increased oxidative stress following induction and consolidation and decreased executive function 2 years later. Younger age at diagnosis was associated with both an increase in oxidative stress and in executive dysfunction; younger age was associated with poorer ability to organize materials in one's environment (r(48) = 0.28, P < 0.05) and with greater oxidated phosphatidylcholine in CSF at the end of chemotherapy (r(48) = −0.27, P < 0.05). As such, younger age appears to be the most prominent moderator of neurocognitive decline.ConclusionsThese results link functional changes to CSF biomarkers and underscore the importance of monitoring cognitive development in young children treated for ALL. Children with less advanced central nervous system development may be particularly vulnerable to the effects of chemotherapy. Pediatr Blood Cancer 2009;53:551–556. © 2009 Wiley‐Liss, Inc.
Cationic photopolymerization of cis‐2,3‐tetramethylene‐1,4,6‐trioxaspiro[4,4]nonane
Authors: Hsu Ying‐Gev , Wan Yen‐Shen 
Published: June 2009

AbstractThe spiro‐orthoester, cis‐2,3‐tetramethylene‐1,4,6‐trioxaspiro[4,4]nonane (cis‐TTN) (I), underwent rapid cationic photopolymerization when exposed to UV light using diphenyliodonium salts as a photoinitiator. The polymer, poly[(trans‐OCB)x′‐(cis‐OCB)x″‐(CHO)y] thus formed consisted of poly(trans‐2‐oxycyclohexyl butanoate) (trans‐OCB)x′ (II), poly(cis‐2‐oxycyclohexyl butanoate) (cis‐OCB)x″ (III), and poly‐ (1,2‐cyclohexene oxide) (CHO)y segments, and no expected pure poly(ether‐ester), that is, poly(2‐oxycyclohexyl butanoate), was isolated. The structure of the polymer was identified, and the mechanism of the reaction was deduced. The polymer thus formed exhibited expansion in volume during cationic photopolymerization when compared to that obtained by conventional cationic polymerization using a Lewis acid (e.g., BF3OEt2, CH3OSO2CF3, or SnCl4) as an initiator, which demonstrated volume shrinkage during polymerization. The volume expansion of the polymer during polymerization was due to (1) the lower content of the higher density (CHO)y segment in the polymer chain and, more importantly, (2) the higher and optimal mole ratio of (trans‐OCB)x′ and (cis‐OCB)x″ segments that led the polymer in a more disordered, less dense, and higher volumetric state. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 3680–3690, 2009
Alternating terpyridine‐endfunctionalized copolymers of styrene and diphenylethylene via anionic polymerization techniques: A detailed characterization study
Authors: Ott Christina , Pavlov Georges M. , Guerrero‐Sanchez Carlos , Schubert Ulrich S. 
Published: June 2009

Abstract1,1‐Diphenylethylenene (DPE) was copolymerized anionically with styrene to yield well‐defined alternating copolymers, which were terminated by reacting the “living” polymeric carbanion species with 4′‐chloro‐2,2′:6′2″‐terpyridine. DPE containing polymers show improved long‐term service temperatures due to the stiffening of the polymer main chain by the bulky phenyl‐rings. In addition, the functionality provided by the terpyridine group allows the synthesis of attractive materials for various fields of application. The obtained polymers were fully characterized by means of nuclear magnetic resonance, gel permeations chromatography, elemental analysis, matrix‐assisted laser desorption/ionization time‐of‐flight mass spectrometry, ultraviolet‐visible spectroscopy, and macromolecular hydrodynamic methods (analytical ultracentrifugation, gel permeation chromatography, intrinsic viscosimetry). In the molar mass range of 2 < M < 25 kg/mol, the scaling relationships between M and hydrodynamic characteristics are obtained. The values of the Kuhn segment length (or persistence length) and hydrodynamic diameters are evaluated and compared with those of linear polystyrene. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 3691–3701, 2009
Poly(ester amide)/clay nanocomposites prepared by in situ polymerization of the sodium salt of N‐chloroacetyl‐6‐aminohexanoic acid
Authors: Morales Laura , Franco Lourdes , Casas María Teresa , Puiggalí Jordi 
Published: June 2009

AbstractPreparation of nanocomposites of organo‐modified montmorillonites and the biodegradable poly(ester amide) derived from glycolic acid and 6‐aminohexanoic acid has been evaluated by the in situ polymerization technique. The reaction was based on the thermal polycondensation of sodium chloroacetylaminohexanoate, which has the formation of the sodium chloride salt as the driving force of the process. Polymerized samples were studied by means of X‐ray diffraction and transmission electron microscopy. The most dispersed structure was obtained by addition of C25A organoclay. Evaluation of thermal stability and crystallization behavior of these samples showed significant differences between the neat polymer and its nanocomposite with C25A. Isothermal and nonisothermal calorimetric analyses of the polymerization reaction revealed that the kinetics was highly influenced by the presence of the silicate particles. Crystallization of the polymer was observed to occur when the process was isothermally conducted at temperatures lower than 145 °C. In this case, dynamic FTIR spectra and WAXD profiles obtained with synchrotron radiation were essential to study the polymerization kinetics. Clay particles seemed to reduce chain mobility and the Arrhenius preexponential factor. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 3616–3629, 2009
Microencapsulation of a functional dye and its UV crosslinking controlled releasing behavior
Authors: Li Gangqiang , Guo Jinbao , Wang Xiao , Wei Jie 
Published: June 2009

AbstractA new family of microcapsules containing photopolymerizable tripropylene glycol diacrylate (TPGDA) was synthesized by using interfacial polymerization. The release behavior of encapsulated dye could be controlled easily by changing the crosslink density of network formed from TPGDA. The chemical structure and properties of microcapsules were characterized by Fourier Transform infrared spectroscopy, scanning electron microscope, differential scanning calorimetry, optical microscope, wide angle X‐ray diffraction and UV‐visible spectrophotometer. The results demonstrate that the higher agitation rate results in a smaller particle size with a narrow size distribution. When core/shell ratio is low, the surface of the microcapsules becomes smooth. Additionally, it was found that UV radiation time is most effective factor to change the CC double bond conversion ratio. After microcapsules were synthesized, the release speed could be changed according to requirement by exposing them to UV light for minutes. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 3630–3639, 2009
Blends of different linear polyamides with hyperbranched aromatic AB2 and A2 + B3 polyesters
Authors: Fan Zhirong , Jaehnichen Klaus , Desbois Philippe , Haeussler Liane , Vogel Roland , Voit Brigitte 
Published: June 2009

AbstractTo explore the possible applications of hyperbranched polymers for modifying linear polyamides, two hyperbranched aromatic polyesters characterized as high Tg polymers possessing phenolic end groups were used in melt mixing with partly aromatic polyamide and commercially available aliphatic polyamide‐6, respectively. Different amounts of both hyperbranched polyesters (from 1 wt % up to 20 wt %) were added to the polyamides, and the influence of these hyperbranched polyesters on the properties of the polyamides was investigated. The hyperbranched polyester based on an AB2 approach was found to be the most effective modifier. A significant increase of the glass transition temperature of the final blend was detected. However, a remarkable reduction of crystallinity as well as complex melt viscosity of those blends was also observed. The use of an A2+B3 hyperbranched polyester as melt modifier for the polyamides was less effective for changing the thermal properties, and the complex melt viscosity of the final material increased since heterogeneous blends were formed. In contrast to that, generally, the addition of the AB2 hyperbranched polyester to the polyamides resulted in homogeneous blends with improved Tg and processability. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 3558–3572, 2009
Copolyfluorenes containing bridged triphenylamine or triphenylamine: Synthesis, characterization, and optoelectronic properties
Authors: Jiang Zuoquan , Zhang Wenjun , Yao Haiqing , Yang Chuluo , Cao Yue , Qin Jingui , Yu Gui , Liu Yunqi 
Published: June 2009

AbstractA novel aryl‐bridged triphenylamine derivative, 7‐t‐butyl‐5,5,9,9‐tetraaryl‐13b‐aza‐naphtho[3,2,1‐de]anthracene (ABTPA) was designed and synthesized. The alternating copolymers of ABTPA/dihexylfluorene (P1) and triphenylamine (TPA)/dihexylfluorene (P2) were synthesized by Suzuki coupling reaction. P1 shows excellent thermal stability with a decomposition temperature of 440 °C and a glass‐transition temperature of 326 °C. The HOMO energy levels of the two polymers are very close (−5.15 eV for P1 and −5.13 eV for P2). The maximum absorption peak of P1 is red shifted by 23 nm with respect to P2, because the incorporation of ABTPA units into the PF backbone enhances the electronic conjugation degree compared with the case of TPA units. The rigidity and the steric hindrance of the ABTPA in P1 result in a small Stokes shift and almost the same emission spectra of P1 between its film and solution. A PLED with simple configurations of ITO/P1/TNS (tetranaphthalen‐2‐yl‐silane)/Alq3 (tris(8‐hydroxyquinolinolato)aluminum)/Al emits a blue light with emission peak at 436 nm, and exhibits a maximum current efficiency of 1.89 cd/A and a maximum luminance of 4183 cd/m2, which is superior to the device with P2 as emissive layer under the identical conditions. These results indicate that ABTPA unit could be a very promising candidate to replace TPA unit and find widely application in organic/polymeric optoelectronic materials. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 3651–3661, 2009
Alkenyl‐functionalized precursors for renewable hydrogels design
Authors: Voepel Jens , Edlund Ulrica , Albertsson Ann‐Christine 
Published: June 2009

AbstractA library of crosslinking chemistries for the hydrogel synthesis based on the hemicellulose acetylated galactoglucomannan (AcGGM) has been developed, demonstrated, and evaluated. A three‐step route was elaborated including (1) the carbonyldiimidazole activation of primary hydroxylated vinylic molecules such as acrylates, vinyl alcohols, and vinyl ethers, (2) the covalent coupling of the alkenyl precursors to the polysaccharide backbone hydroxyls, and (3) the radical crosslinking of pendant vinyl functionalities affording a hydrophilic network. Crosslinking strategies explored include redox initiation and photo initiation, with an effort to adapt the suggested synthesis routes to benign conditions. The different functionalization strategies were shown to influence the resulting gel's properties. Varying the crosslinking media was found to be a strong tool to tune the properties of the gels. Modifications were in all cases verified by means of NMR and FTIR, and the gels were characterized with respect to swelling capacity and rheological parameters. It was shown that by adjusting the synthesis parameters, the resulting properties of the AcGGM gels could be custom‐made for a given performance. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 3595–3606, 2009
Anionic alternating copolymerization behavior of bifunctional six‐membered lactone and glycidyl phenyl ether
Authors: Uenishi Kazuya , Sudo Atsushi , Endo Takeshi 
Published: June 2009

AbstractA copolymerization of 10‐methyl‐2H,8H‐benzo‐[1,2‐b:5,4‐b′]bipyran‐2,8‐dione (1) and glycidyl phenyl ether (GPE) was studied. 1 was a bislactone designed as a bifunctional analogue of 3,4‐dihydrocoumarin (DHCM), of which anionic 1:1 alternating copolymerization with GPE has been reported by us, previously. This alternating nature was inherited by the present copolymerization of 1 and GPE, leading to an intriguing copolymerization behavior in contrast to the ordinary statistical copolymerizations of monofunctional monomers and bifunctional monomers usually controlled by the proportional dependence of the crosslinking density on the monomer feed ratio: (1) When the feed ratio [GPE]0/[1]0 was 1, the two monomers underwent the 1:1 alternating copolymerization. In this case, 1 behaved as a monofunctional monomer, that is, only one of the two lactones in 1 participated in the copolymerization allowing the other lactone moiety to be introduced into the side chain almost quantitatively. (2) Increasing the feed ratio [GPE]0/[1]0 to larger than 4 allowed almost all of the lactone moieties to participate in the copolymerization system to give the corresponding networked polymers efficiently. The compositions of the copolymers [GPE unit]/[1‐derived acyclic ester unit] were always biased to smaller values than the feed ratios [GPE]0/[lactone moiety in 1]0 by the intrinsic 1:1 alternating nature of the copolymerization. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 3662–3668, 2009
Raft polymerization of MMA in the presence of ferrocene: A new way to realize the rate enhancement
Authors: Chen Qifeng , Zhang Zhengbiao , Zhou Nianchen , Zhu Jian , Pan Qinmin , Zhu Xiulin 
Published: June 2009

AbstractFerrocene (Fe(Cp)2) was added to a thermal initiation of reversible addition‐fragmentation chain transfer (RAFT) polymerization of methyl methacrylate (MMA) with 2‐cyanoprop‐2‐yl 1‐dithionaphthalate (CPDN) as the RAFT agent at 115 °C. It was found that the polymerization was greatly promoted after the addition of Fe(Cp)2 while retaining the characteristics of a typical RAFT polymerization. It was proposed that the formation of a redox initiation system, in which the poly(methyl methacrylate) peroxide (PMMAP) generated in situ as the oxidizer and Fe(Cp)2 as the reducer, was possibly the reason for the interesting polymerization phenomenon. Such a redox initiation mechanism was further validated with ascorbic acid (VC) as the reducer instead of Fe(Cp)2. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 3607–3615, 2009
Large‐compound vesicle‐encapsulated multiwalled carbon nanotubes: A unique route to nanotube composites
Authors: Zou Peng , Shi Gang‐Yin , Pan Cai‐Yuan 
Published: June 2009

AbstractA simple and unique strategy for preparation of large‐compound vesicle (LCV)‐encapsulated multiwalled carbon nanotubes (MWCNTs) has been developed, and this involves dispersion of MWCNTs in H‐shaped copolymers solution in DMF and encapsulation of MWCNTs with LCVs formed from hydrolysis and polycondensation of Si(OCH3)3 groups in the amphiphilic H‐shaped copolymers, (PTMSPMA)2PEG(PTMSPMA)2. This unique noncovalent approach is nondestructive, and the original structure of MWCNTs remains in the resultant MWCNTs/LCVs nanocomposites. The morphologies of nanocomposites LCVs/MWCNTs are controlled by the chain length ratio (NPTMSPMA/NPEG) of PTMSPMA to PEG. For the H‐shaped copolymers with NPMSPMA/NPEG ≤ 1.7, they self‐assembled to form LCVs with dense cavities in the presence of MWCNTs in a mixture of DMF/H2O. When this ratio was more than 2.0, the large‐compound micelle‐wrapped MWCNTs were produced. This approach is potentially useful for preparation of MWCNTs encapsulated with various morphologies of polymers. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 3669–3679, 2009
Scaling of the strain hardening modulus of glassy polymers with the flow stress
Authors: Robbins Mark O. , Hoy Robert S. 
Published: June 2009

AbstractIn a recent letter, Govaert et al. examined the relationship between strain hardening modulus Gr and flow stress σflow for five different glassy polymers. In each case, results for Gr at different strain rates or different temperatures were linearly related to the flow stress. They suggested that this linear relation was inconsistent with simulations. Data from previous publications and new results are presented to show that simulations also yield a linear relation between modulus and flow stress. Possible explanations for the change in the ratio of modulus to flow stress with temperature and strain rate are discussed. © 2009 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 47: 1406–1411, 2009