bluuebunny/crossref_metadata_2025_split huggingface dataset:
Polymerization of Diphenylacetylenes with Polar Functional Groups by the Grubbs–Hoveyda Ru Carbene Catalyst
Authors: Katsumata Toru , Shiotsuki Masashi , Masuda Toshio 
Published: July 2006

AbstractSummary: Polymerization of various diphenylacetylene derivatives was investigated by using Grubbs–Hoveyda catalyst (1). Owing to excellent tolerance for polar functional groups, catalyst 1 polymerized diphenylacetylene (2) and diphenylacetylene derivatives bearing silyl (3), siloxy (4 and 5), ester (6 and 7), amide (8–10), and carbamate (11) groups. It is noteworthy that polymerization of monomers 6–11, which have polar functional groups, has been impossible until now due to the deactivation of well‐known Ta catalysts. Although monomers having ester groups (6 and 7) hardly polymerized, their copolymerization with trimethylsilyl group‐containing diphenylacetylene (3) afforded copolymers, which incorporated ester moieties more than the monomer feed ratio. While polymers with relatively nonpolar groups [poly(3)–poly(5)] were soluble in hydrocarbon solvents such as cyclohexane and hexane, polar group‐bearing homo‐ and copolymers (poly(10), poly(11), etc.) dissolved in polar solvents (e.g., DMF and acetone). Polymerization of 1‐(4‐tert‐butyldimethylsiloxy)phenyl‐2‐(4‐fluorophenyl)acetylene (5) gave a high molecular weight polymer ($\overline M _{\rm n}$ = 178 000) suitable for membrane fabrication, and the membrane of this polymer showed higher gas permeability and permselectivity than that of the Ta‐based polymer.Polymerization of various diphenylacetylenes by the Ru Grubbs–Hoveyda catalyst.magnified imagePolymerization of various diphenylacetylenes by the Ru Grubbs–Hoveyda catalyst.
Electronic Transitions of Polyalkylthiophenes Partially Derivatized with NLO Chromophores: A Theoretical and Experimental Study
Authors: Lanzi Massimiliano , Bertinelli Franco , Paganin Luisa , Costa‐Bizzarri Paolo , Cesari Gaia 
Published: July 2006

AbstractSummary: The UV‐vis spectral profiles of some alkylthiophene copolymers in CHCl3 solutions, variously substituted with an azobenzenic NLO chromophore have been carefully analyzed and distinct intensity contributions have been assigned to the overlapped electronic transitions appearing in the lower energy part of the spectra. The different spectral behaviours are influenced by the chromophore content, the length of the alkylic side‐chain of the plastifying comonomer and, more significantly, by the number of the carbon atoms in the oligomethylenic spacer between the chromophoric group and the conjugated polythiophenic chain. This latter finding can be correlated with the strong steric hindrance caused by chromophore crowding in close proximity to the polymeric backbone. As the intensity distributions may be reasonably compared with the NLO properties, identification of the above parameters and of their role is an important step towards the synthesis of polyalkylthiophenes with predictable electronic properties and the development of materials with enhanced NLO characteristics.Graphical surfaces of the highest‐occupied (HOMO)s and the lowest unoccupied (LUMO) molecular orbitals involved in the first three π–π* electronic transitions of the chromophoric system.magnified imageGraphical surfaces of the highest‐occupied (HOMO)s and the lowest unoccupied (LUMO) molecular orbitals involved in the first three π–π* electronic transitions of the chromophoric system.
Phase Diagram for a System of Polydisperse Components Consisting of the Precursor of an Epoxy/Diamine Thermoset and a Thermoplastic: Analysis Based on a Lattice Theory Model
Authors: Rico Maite , Ramírez Carmen , Montero Belén , Díez Javier , López Joaquín 
Published: July 2006

AbstractSummary: The miscibility of a thermoplastic modifier with the precursors of an epoxy/diamine thermoset without chemical reaction was studied thermodynamically. The experimental cloud point curve showed a UCST behavior. A model based on the Flory‐Huggins lattice theory and on the Koningsveld approach was used for the thermodynamic analysis, in which the polydispersity of components was taken into account and the interaction parameter was considered depending on the temperature and composition. A phase diagram for the unreacted system was obtained. Calculations of species distributions in both separated phases were realized for different compositions of the modifier. Finally, the miscibility of our system was compared with that of the same system without diamine, obtaining a greater miscibility in the system with diamine.Phase diagram for the system formed by the precursors of an epoxy thermoset without chemical reaction modified with different amounts of polystyrene.magnified imagePhase diagram for the system formed by the precursors of an epoxy thermoset without chemical reaction modified with different amounts of polystyrene.
An inspection game: Taking account of fulfillment probabilities of players' aims
Authors: Hohzaki Ryusuke , Kudoh Diasuke , Komiya Toru 
Published: July 2006

AbstractThis paper deals with an inspection game of customs and a smuggler. The customs can take two options of assigning a patrol or not. The smuggler has two strategies of shipping its cargo of contraband or not. Two players have several opportunities to take actions during a limited number of days. When both players do, there are some possibilities that the customs captures the smuggler and, simultaneously, the smuggler possibly makes a success of the smuggling. If the smuggler is captured or there remain no days for playing the game, the game ends. In this paper, we formulate the problem into a multi‐stage two‐person zero‐sum stochastic game and investigate some characteristics of the equilibrium solution, some of which are given in a closed form in a special case. There have been some studies so far on the inspection game. However, some consider the case that the smuggler has only one opportunity of smuggling or the perfect‐capture case that the customs can certainly arrest the smuggler on patrol, and others think of a recursive game without the probabilities of fulfilling the players' purposes. In this paper, we consider the inspection game taking account of the fulfillment probabilities of the players' aims. © 2006 Wiley Periodicals, Inc. Naval Research Logistics, 2006
Recovering a time‐dependent coefficient in a parabolic equation from overspecified boundary data using the pseudospectral Legendre method
Authors: Shamsi M. , Dehghan Mehdi 
Published: July 2006

AbstractThe aim of this article is to discuss the problem of finding the unknown function u(x,t) and the time‐dependent coefficient a(t) in a parabolic partial differential equation. The pseudospectral Legendre method is employed to solve this problem. The results of numerical experiments are given. © 2006 Wiley Periodicals, Inc. Numer Methods Partial Differential Eq, 2007
Comparison of childhood myelodysplastic syndrome, AML FAB M6 or M7, CCG 2891: Report from the Children's Oncology Group
Authors: Barnard Dorothy R. , Alonzo Todd A. , Gerbing Robert B. , Lange Beverly , Woods William G. 
Published: July 2006

AbstractBackgroundMyelodysplastic syndromes (MDS), acute erythroleukemia (FAB M6), and acute megakaryocytic leukemia (FAB M7) have overlapping features.ProcedureChildren without Down syndrome or acute promyelocytic leukemia who were newly diagnosed with primary myelodysplastic syndrome or acute myeloid leukemia (AML) M6 or M7 were compared to children with de novo AML M0–M5. All children were entered on the Children's Cancer Group therapeutic research study CCG 2891.ResultsThe presentation and outcomes of the 132 children diagnosed with MDS (60 children), AML FAB M6 (19 children), or AML FAB M7 (53 children) were similar. Children with AML FAB M7 were diagnosed at a significantly younger age (P = 0.001). Children with MDS, M6, or M7 had significantly lower white blood cell (WBC) counts (P = 0.001), lower peripheral blast counts (P < 0.001), and an increased frequency of −7/7q‐ (P = 0.003) at presentation. All three groups had significantly inferior overall survival (OS) (P < 0.001) and event free survival (P < 0.001) compared with the 748 children diagnosed with AML FAB M0–M5 when assessed from entry on study. This poor survival was largely attributable to induction death and failure. However, when assessed from successful completion of induction therapy, the 5‐year OS (P = 0.090)(49.1 vs. 56.9%) and disease‐free survival (DFS) (P = 0.113)(38.0 vs. 46.3%) therapy were not significantly different from other children with AML.ConclusionsChildhood AML FAB M6 and AML M7 resemble MDS in presentation, poor induction success rates, and outcomes. Pediatr Blood Cancer 2007;49:17–22. © 2006 Wiley‐Liss, Inc.
Peripheral neuropathy associated with leflunomide: is there a risk patient profile?
Authors: Martin Karin , Bentaberry Fabrice , Dumoulin Chantal , Miremont‐Salamé Ghada , Haramburu Françoise , Dehais Joel , Schaeverbeke Thierry 
Published: July 2006

AbstractPurpose(i) To monitor the potential clinical neurotoxic symptoms in patients treated with leflunomide in daily practice and (ii) to describe the characteristics of patients presenting with this peripheral nervous system symptoms.MethodAll patients treated with leflunomide between May 2000 and April 2003 and followed in the rheumatology department of the University Hospital participated in the study. Data concerning treatment patterns with leflunomide, demographic and disease characteristics were obtained from clinical charts. Neuropathy was diagnosed with nerve conduction study (NCS). Cases of neuropathy were described and then compared to other patients using univariate analyses.ResultsOne hundred and thirteen patients were included in the study. M/F sex ratio was 0.45. Mean age at start of treatment was 55.6 years (range = 27–81). During the study period, eight incident cases of peripheral neuropathy and two cases of worsening of preexisting neuropathy were reported (incidence: 9.8%). Compared with other patients, neuropathy cases were older (69 vs. 54 years, p = 0.0006), more often diabetic (30% vs. 2.9%, p = 0.009) and more often treated with potentially neurotoxic drugs (20% vs. 1.9%, p = 0.039). At least one risk factor (potentially neurotoxic drug or diabetes) was found in 50% of patients with neuropathy versus 4% of patients without neuropathy (56% PPV, 96% NPV).ConclusionCases of toxic neuropathy have been observed during treatment of rheumatoid arthritis with leflunomide. Their occurrence seems to be associated with known risk factors. Careful monitoring of the patient's neurological status during leflunomide treatment is therefore mandatory. Copyright © 2006 John Wiley & Sons, Ltd.
Microwave‐assisted synthesis of a novel phosphorus‐containing spiroorthoester, characterization and cationic polymerization
Authors: Canadell J. , Mantecón A. , Cádiz V. 
Published: July 2006

AbstractA new phosphorus‐containing spiroorthoester, (1,4,6‐trioxaspiro [4,4] nonan‐2‐yl)‐methyl 3‐[10‐(9,10‐dihydro‐9‐oxa‐9‐phosphaphenanthrene‐10‐oxide)]‐propanoate (SOE‐P), was synthesized under microwave irradiation with a short reaction time (1 h), because classical thermal heating did not lead to the desired product. The structure of the new monomer was confirmed by 1H, 13C, and 31P. SOE‐P was homopolymerized and copolymerized with phenylglycidyl ether with ytterbium triflate as a cationic initiator in DSC experiments. These reactions were monitored by FTIR/ATR, and the formation of poly(ether‐ester)s with a pendant bulky phosphorylated group was shown. © 2006Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 4722–4730, 2006
Relationship between the liquid crystallinity and field‐effect‐transistor behavior of fluorene–thiophene‐based conjugated copolymers
Authors: Lim Eunhee , Kim Young Mi , Lee Jeong‐Ik , Jung Byung‐Jun , Cho Nam Sung , Lee Jaemin , Do Lee‐Mi , Shim Hong‐Ku 
Published: July 2006

AbstractA series of fluorene–thiophene‐based semiconducting materials, poly(9,9′‐dioctylfluorene‐alt‐α,α′‐bisthieno[3,2‐b]thiophene) (F8TT2), poly(9,9′‐di(3,6‐dioxaheptyl)fluorene‐alt‐thieno[3,2‐b]thiophene) (BDOHF8TT), poly(9,9′‐di(3,6‐dioxaheptyl)fluorene‐alt‐bithiophene) (BDOHF8T2), and poly(9,9′‐dioctylfluorene‐co‐bithiophene‐co‐[4‐(2‐ethylhexyloxyl)phenyl]diphenylamine) (F8T2TPA), was synthesized through a palladium‐catalyzed Suzuki coupling reaction. F8TT2, BDOHF8TT, BDOHF8T2, and F8T2TPA films exhibited photoluminescence maxima at 523, 550, 522, and 559 nm, respectively. Solution‐processed field‐effect transistors (FETs) fabricated with all the copolymers except F8T2TPA showed p‐type organic FET characteristics. Studies of the differential scanning calorimetry scans and FETs of the polymers revealed that more crystalline polymers gave better FET device performance. The greater planarity and rigidity of thieno[3,2‐b]thiophene in comparison with bithiophene resulted in higher crystallinity of the polymer backbone, which led to improved FET performance. On the other hand, the random incorporation of the triphenylamine moiety into F8T2TPA caused the polymer chains to lose crystallinity, resulting in an absence of FET characteristics. With this study, we could assess the liquid‐crystallinity dependence of the field‐effect carrier mobility on organic FETs based on liquid‐crystalline copolymers. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 4709–4721, 2006
Psychosocial factors and patients' preferences for adjuvant chemotherapy in early breast cancer
Authors: Duric Vlatka M. , Butow Phyllis N. , Sharpe Louise , Boyle Frances , Beith Jane , Wilcken Nicholas R.C. , Heritier Stephane , Coates Alan S. , John Simes R. , Stockler Martin R. 
Published: July 2006

AbstractPurpose: Many women who have had adjuvant chemotherapy for early breast cancer judge small benefits sufficient to make it worthwhile despite significant side effects and inconvenience. The rationality of these preferences has been questioned. We sought to better understand such preferences by assessing associations between preferences and psychosocial factors, and by asking women who judged negligible benefits sufficient to explain why.Methods: We recruited 83 consecutive consenting women who had completed adjuvant chemotherapy for early breast cancer 3–34 months earlier. Preferences were elicited during a structured, scripted interview using four sets of validated, hypothetical trade‐off scenarios about the possible benefits of adjuvant chemotherapy on survival times (5 and 15 years) and rates (65 and 85% at 5 years). Women completed questionnaires measuring anxiety, depression, optimism, quality and quantity of social support, and illness perceptions.Results: More than half the women judged benefits of 1 day or 0.1% sufficient to make adjuvant chemotherapy worthwhile. The most important factors in multivariable models were whether the woman had dependants and number of non‐specific symptoms attributed to breast cancer and adjuvant chemotherapy since completing treatment. The proportion of variance explained was modest. Preferences were not associated with: scores for anxiety, optimism, and perceived quality and quantity of social support. Explanations for judging negligible benefits sufficient included minimising regret, parenting concerns, doubts about the information provided and feeling that they had no choice.Conclusions: Preferences were highly variable and influenced by women's unique circumstances and attitudes, but not by their anxiety or optimism scores. Copyright © 2006 John Wiley & Sons, Ltd.
Electrostatic contribution to the binding stability of protein–protein complexes
Authors: Dong Feng , Zhou Huan‐Xiang 
Published: July 2006

AbstractTo investigate roles of electrostatic interactions in protein binding stability, electrostatic calculations were carried out on a set of 64 mutations over six protein–protein complexes. These mutations alter polar interactions across the interface and were selected for putative dominance of electrostatic contributions to the binding stability. Three protocols of implementing the Poisson‐Boltzmann model were tested. In vdW4 the dielectric boundary between the protein low dielectric and the solvent high dielectric is defined as the protein van der Waals surface and the protein dielectric constant is set to 4. In SE4 and SE20, the dielectric boundary is defined as the surface of the protein interior inaccessible to a 1.4‐Å solvent probe, and the protein dielectric constant is set to 4 and 20, respectively. In line with earlier studies on the barnase–barstar complex, the vdW4 results on the large set of mutations showed the closest agreement with experimental data. The agreement between vdW4 and experiment supports the contention of dominant electrostatic contributions for the mutations, but their differences also suggest van der Waals and hydrophobic contributions. The results presented here will serve as a guide for future refinement in electrostatic calculation and inclusion of nonelectrostatic effects. Proteins 2006. © 2006 Wiley‐Liss, Inc.
Influence of Mn valence bond on ferromagnetic properties of corn‐like Zn1−xMnx O nanorods
Authors: Cong C. J. , Zhang K. L. 
Published: July 2006

AbstractCorn‐like Zn1−x Mnx O nanorods were synthesized by the rheological phase reaction‐precursor method. X‐ray diffraction analysis reveals that nanocrystalline Zn1−x Mnx O has a wurtzite structure, and the lattice constants of Zn1−x Mnx O increase slightly with increasing Mn2+ contents. Transmission electron microscopy observation shows that the corn‐like Zn1−x Mnx O nanorods consisted of polycrystal nanoparticles, and the diameter of the nanoparticles is about 10–13 nm. The diameter and length of the nanorods are about 150–260 nm and 0.33–1.0 µm, respectively. X‐ray photoelectron spectroscopy measurement indicates that there are different Mn valence bonds in corn‐like Zn1−x Mnx O nanorods. Furthermore, two additional Raman peaks were observed. One peak is considered to have an origin related to the incorporation of Mn ions onto the Zn site of the ZnO lattice; the other may be attributed to the Mn‐based compounds phase. Magnetization measurements under field‐cooling conditions reveal that the Zn1−x Mnx O nanostructures exhibit ferromagnetic behaviors, and both the susceptibility and coercive force of Zn0.95Mn0.05O are larger than that of Zn0.97Mn0.03O and Zn0.93Mn0.07O. The difference of the ferromagnetic properties of Zn1−x Mnx O nanostructures may be attributed to the Mn2+ content. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Survey and mechanism of skin depigmenting and lightening agents
Authors: Parvez Shoukat , Kang Moonkyu , Chung Hwan‐Suck , Cho Chongwoon , Hong Moo‐Chang , Shin Min‐Kyu , Bae Hyunsu 
Published: July 2006

AbstractThe type and amount of melanin synthesized by the melanocyte, and its distribution pattern in the surrounding keratinocytes, determines the actual color of the skin. Melanin forms through a series of oxidative reactions involving the amino acid tyrosine in the presence of the enzyme tyrosinase.Tyrosinase catalyses three different reactions in the biosynthetic pathway of melanin in melanocytes: the hydroxylation of tyrosine to l‐DOPA and the oxidation of l‐DOPA to dopaquinone; furthermore, in humans, dopaquinone is converted by a series of complex reactions to melanin.Among the skin‐lightening and depigmenting agents, magnesium‐l‐ascorbyl‐2‐phosphate (MAP), hydroxyanisole, N‐acetyl‐4‐S‐cysteaminylphenol, arbutin (hydroquinone‐beta‐d‐glucopyranoside) and hydroquinone (HQ) are the most widely prescribed worldwide. However, with reports of potential mutagenicity and epidemics of ochronosis, there has been an increasing impetus to find alternative herbal and pharmaceutical depigmenting agents. A review of the literature reveals that numerous other depigmenting or skin‐lightening agents are either in use or in investigational stages. Some of these, such as kojic, glycolic and azelaic acids, are well known to most dermatologists. Others have been discovered and reported in the literature more recently.Several depigmentation and lightening agents are discussed, including their historical background, biochemical characteristics, type of inhibition and activators from various sources. In addition, the clinical importance of mushroom tyrosinase as a recent prospect is discussed in this paper. Copyright © 2006 John Wiley & Sons, Ltd.
Electrospray ionization tandem mass spectrometry of biphenyl‐modified oligo(deoxy)ribonucleotides
Authors: Tromp Jan M. , Schürch Stefan 
Published: July 2006

AbstractAntisense oligonucleotides and aptamers are important candidates for future therapeutic applications. Different structural modifications are introduced into oligonucleotides to obtain high affinity and binding specificity. Sequence elucidation of oligonucleotides incorporating a wide variety of modifications presents an analytical challenge, as the standard protocols cannot be applied. Mass spectrometry has the potential to solve complex structural problems. However, a better understanding of the fundamental aspects of gas‐phase dissociation of modified DNA and RNA is needed.In this work the influence of specific chemical modifications on backbone dissociation is pointed out. Biphenyl‐modified oligo(deoxy)ribonucleotides, which incorporate C‐glycosidic bound abasic nucleobase substitutes, were subjected to collision‐induced dissociation in an electrospray tandem mass spectrometer, with the goal to investigate the role of nucleobase loss on backbone dissociation. DNA bearing biphenyl nucleobase substitutes show abundant [a‐B]‐ and w‐ions generated by cleavage of the 3′‐CO bonds, except for the phosphodiester groups adjacent to the biphenyl modifications. At these positions no dissociation was observed, demonstrating the dependence of DNA backbone dissociation on nucleobase loss. Also, no evidence for a base loss independent mechanism responsible for formation of w‐ions was found. RNA incorporating biphenyl nucleobase substitutes fragment into c‐ and y‐ions resulting from cleavage of the 5′‐PO bond. Adjacent to the biphenyl modifications no altered dissociation behavior was found. This leads to the conclusion that dissociation of RNA is independent of the 1′‐modification and, therefore, independent of nucleobase loss. Copyright © 2006 John Wiley & Sons, Ltd.