bluuebunny/crossref_metadata_2025_split huggingface dataset:
Organische Halbleiter für aus Lösung prozessierbare Feldeffekttransistoren
Authors: Allard Sybille , Forster Michael , Souharce Benjamin , Thiem Heiko , Scherf Ullrich 
Published: March 2008

AbstractDie kostengünstige Fertigung flexibler elektronischer Bauelemente dürfte in Zukunft stark von der Entwicklung aus Lösung prozessierbarer, organischer Halbleitermaterialien profitieren. Besondere Aufmerksamkeit gilt dabei zurzeit löslichen Halbleitern für organische Feldeffekttransistoren (OFETs). Die bis vor einiger Zeit vorgenommene Trennung zwischen “kleinen Molekülen” und polymeren Materialien spielt mittlerweile keine Rolle mehr – entscheidend ist vielmehr die Verarbeitbarkeit der Materialien aus Lösung zu homogenen Halbleiterschichten mit optimalen elektronischen Eigenschaften (hohe Ladungsträgermobilität, geringe Schwellspannung, hohes An/Aus‐Verhältnis). Die Materialien der Wahl sind hier lösliche Oligoacene, lösliche Oligo‐ und Polythiophene oder entsprechende Copolymere sowie Oligo‐ und Polytriarylamine. Mikro‐ oder nanokristalline Materialien bieten dabei allgemein den Vorteil etwas höherer Ladungsträgermobilitäten; amorphe, glasartige Materialien könnten dies jedoch durch eine einfachere und besser reproduzierbare Verarbeitung wettmachen.
Gamma‐retroviral vectors enveloped with an antibody and an engineered fusogenic protein achieved antigen‐specific targeting
Authors: Yang Haiguang , Ziegler Leslie , Joo Kye‐Il , Cho Taehoon , Lei Yuning , Wang Pin 
Published: March 2008

AbstractDevelopment of methods to engineer gamma‐retroviral vectors capable of transducing target cells in a cell‐specific manner could impact the future of the clinical application of gene therapy as well as the understanding of the biology of transfer gene vectors. Two molecular events are critical for controlling the entry of gamma‐retroviral vectors to target cells: binding to cell‐surface receptors and the subsequent fusion of viral vector membrane and cellular membrane. In this report, we evaluated a method to incorporate a membrane‐bound antibody and a fusogenic molecule to provide binding and fusion functions respectively, into gamma‐retroviral vectors for targeted gene delivery. An anti‐CD20 antibody and a fusogenic protein derived from Sindbis virus glycoprotein could be efficiently co‐displayed on the surface of viral vectors. Vectors bearing anti‐CD20 antibody conferred their binding specificity to cells expressing CD20. Enhanced in vitro transduction towards CD20‐expressing cells was observed for gamma‐retroviral vectors displaying both an antibody and a fusogen. We found that the biological activity of the fusogen played an important role on the efficiency of such a targeting strategy and were able to engineer several mutant forms of the fusogen exhibiting elevated fusion function to improve the overall efficiency of targeted transduction. We devised an animal model to show that subcutaneous injection of such engineered vectors to the areas xenografted with target cells could achieve targeted gene delivery in vivo. Taken together, we demonstrated as proof‐of‐principle a flexible and modular two‐molecule strategy for engineering targeting gamma‐retroviral vectors. Biotechnol. Bioeng. 2008;101: 357–368. © 2008 Wiley Periodicals, Inc.
A new technique for primary hepatocyte expansion in vitro
Authors: Cho Cheul H. , Berthiaume François , Tilles Arno W. , Yarmush Martin L. 
Published: March 2008

AbstractThe current application for many potential cell‐based treatments for liver failure is limited by the low availability of mature functional hepatocytes. Although adult hepatocytes have a remarkable ability to proliferate in vivo, attempts to proliferate adult hepatocytes in vitro have been less successful. In this study, we investigated the effect of coculture cell type on the proliferative response and the functional activities of hepatocytes. We show, for the first time, a robust proliferative response of primary adult rat hepatocytes when cocultured with mouse 3T3‐J2 fibroblasts. Hepatocytes cultured at low density on growth‐arrested 3T3‐J2 fibroblast feeder layers underwent significantly higher proliferation rates than when cultured on feeder layers made of four other cell types. Increasing colony size correlated with an increase in hepatocellular functions. The proliferating hepatocytes retained their morphologic, phenotypic, and functional characteristics. Using a cell patterning technique, we found that 3T3‐J2 fibroblasts stimulate DNA synthesis in hepatocytes by short‐range heterotypic cell–cell interactions. When hepatocytes that proliferated in cocultures were harvested and further subcultured either on 3T3‐J2 fibroblast feeders or in the collagen sandwich configuration, their behavior was similar to that of freshly isolated hepatocytes. We conclude that adult rat hepatocytes can proliferate in vitro in a coculture cell type‐dependent manner, and can be serially propagated by coculturing with 3T3‐J2 fibroblasts while maintaining their differentiated characteristics. Our results also suggest that one of the major reasons for the functional differences in hepatocyte cocultures may be due to the different proliferative responses of hepatocytes as a function of coculture cell type. This study provides new insights in the roles of coculture cell types and cell–cell interactions in the modulation of hepatic proliferation and function. Biotechnol. Bioeng. 2008;101: 345–356. © 2008 Wiley Periodicals, Inc.
Thiophene Polymer Semiconductors for Organic Thin‐Film Transistors
Authors: Ong Beng S. , Wu Yiliang , Li Yuning , Liu Ping , Pan Hualong 
Published: March 2008

AbstractPrinted organic thin‐film transistors (OTFTs) have received great interests as potentially low‐cost alternative to silicon technology for application in large‐area, flexible, and ultra‐low‐cost electronics. One of the critical materials for TFTs is semiconductor, which has a dominant impact on the transistor properties. We review here the structural studies and design of thiophene‐based polymer semiconductors with respect to solution processability, ambient stability, molecular self‐organization, and field‐effect transistor properties for OTFT applications. We show that through judicial monomer design, delicately controlled π‐conjugation, and strategically positioned pendant side‐chain distribution, novel solution‐processable thiophene polymer semiconductors with excellent self‐organization ability to form extended lamellar π‐stacking orders can be developed. OTFTs using semiconductors of this nature processed in ambient conditions have provided excellent field‐effect transistor properties.
Systematic Reactions of [Pt(PF3)4]
Authors: Drews Thomas , Rusch Dieter , Seidel Stefan , Willemsen Stefan , Seppelt Konrad 
Published: March 2008

AbstractTetrahedral [Pt(PF3)4] reacts with H+ to form trigonal bipyramidal [Pt(PF3)4H]+. This in turn looses PF3 to form square‐planar [Pt(PF3)3H]+. The complex [Pt(PF3)4] can be oxidized with AsF5 to form the square‐planar complex, [Pt(PF3)4]2+, which can be more conveniently obtained from PtF4 and PF3 in HF/SbF5 solution. [Pt(PF3)4]2+ reacts with F− in HF under cluster formation to [Pt4(PF3)8H]+.
Sterically and Polarity‐Controlled Reactions of tBuLi with PCH‐NR Heterocycles: Novel Heterocyclic P‐ and P,O‐Ligands and Preliminary Tests in Transition‐Metal Catalysis
Authors: Aluri Bhaskar R. , Kindermann Markus K. , Jones Peter G. , Heinicke Joachim 
Published: March 2008

Abstract(1R)‐1,3‐Benzazaphospholes 1 a–c, PCH‐NR heterocycles of the indole type, react with tBuLi in two ways, depending on the steric demand of the N‐substituent and the polarity of the medium. The presence of small N‐alkyl groups induces CH‐deprotonation in the 2‐position to give hetaryllithium reagents 2 a and 2 b, whereas bulky N‐substituents and nonpolar solvents change the reactivity towards addition at the PC bond. The preferred regioselectivity is tert‐butylation at phosphorus, occurring with excellent diastereoselectivity for trans‐adducts 3 b and 3 c, but the inverse tert‐butylation at C2 to 5 b was also observed. N‐Neopentyl groups, with intermediate steric demand, give rise to formation of mixtures in ethers but allow switching either to selective CH lithiation in THF/KOtBu or to addition in pentane. Bulkier N‐adamantyl groups always cause preferred addition. Protonation, silylation, and carboxylation were used to convert the PCLi‐NR, (E)‐tBuP‐CHLi‐NR, and LiP‐CH(tBu)‐NR species into the corresponding σ2‐P or σ3‐P compounds 4 b and 6 a,b, 7 b,c, or 8 b–10 b with additional N and/or O donor sites. Slow diffusion‐controlled air oxidation of 10 b led to the meso‐diphosphine 11 b. Preferred η1‐P coordination was shown for an [Rh(cod)Cl] complex 12 b, and the potential of the new ligands 4 b and 7 b in catalysis was demonstrated by examples of Pd‐catalyzed CN coupling and Ni‐catalyzed ethylene oligomerization (TON>6300). Crystal structures of 6 b, 11 b, and 12 b are presented.
Inhibitors of Inducible NO Synthase Expression: Total Synthesis of (S)‐Curvularin and Its Ring Homologues
Authors: Elzner Stephan , Schmidt Denise , Schollmeyer Dieter , Erkel Gerhard , Anke Timm , Kleinert Hartmut , Förstermann Ulrich , Kunz Horst 
Published: March 2008

Abstract(S)‐Curvularin and its 13‐, 14‐, and 16‐membered lactone homologues were synthesized through a uniform strategy in which a Kochi oxidative decarboxylation and ring‐closing metathesis reactions constitute the key processes. In the evaluation of the anti‐inflammatory effects of the synthesized compounds in assays using cells stably transfected with a human iNOS promoter–luciferase reporter gene construct, the 14‐ and 16‐membered homologues showed a slightly higher inhibitory effect towards iNOS promoter activity than curvularin itself. However, the larger ring homologues also exhibited higher cytotoxicity, manifest in downregulated eNOS promoter activity. In contrast, the di‐O‐acetyl and 4‐chloro derivatives of (S)‐curvularin showed higher inhibitory efficiency towards induction of the iNOS promoter and less negative effect on eNOS promoter activity than curvularin.
Density Functional Theory Studies of the Magnetostructural Correlations in the Cyano‐Bridged Mo2Ni and Mo2Ni3 Systems
Authors: Zhang Yi‐Quan , Luo Cheng‐Lin 
Published: March 2008

AbstractA theoretical density functional study of the magnetostructural correlations in a series of cyano‐bridged MoNi systems is presented. Our calculations by two approaches with several local density approximations (LDAs) and generalized gradient approximations (GGAs) show that: (1) the influence of the next‐nearest‐neighbor MoMo interactions on the MoNi interactions can be omitted; (2) the MoNi interactions strengthen with an increase in the Ni–Nbrid–Cbrid angle in the range 135° to 175° for all the functionals; (3) increasing the number of exchange coupling interactions from one to two will decrease the ferromagnetic MoNi interactions, but the influence of further increasing the number of exchange coupling interactions from two to three or four on the MoNi interactions is very small, because the peripheral units do not surround the same central metal ion in the MoNi systems that we investigated. Kahn's theory was used to interpret the above results.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)
Facile Endoperoxypropellane Synthesis by Manganese(III) Acetate‐Mediated Aerobic Oxidation
Authors: Asahi Kentaro , Nishino Hiroshi 
Published: March 2008

AbstractManganese(III)‐catalyzed aerobic oxidation of combinations of 3‐(2‐oxoethyl)piperidine‐2,4‐diones and 1,1‐diarylethenes at room temperature produced structurally interesting trioxa‐aza[4.4.3]propellanes in good yields. Similar reactions using 2‐(2‐oxoethyl)cyclohexane‐1,3‐diones also produced the corresponding endoperoxy[4.4.3]propellanes. On the other hand, 3‐oxopropyl‐substituted cycloalkane‐1,3‐diones did not give the desired propellanes, 1,2‐dioxabicyclic propellane precursors were formed instead in excellent yields. The precursors could be converted into the corresponding propellanes in the presence of a Lewis acid. The mechanism for the formation of the propellanes is also described. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)
Synthesis of Enantiopure Aliphatic Acetylene Alcohols and Determination of Their Absolute Configurations by 1H NMR Anisotropy and/or X‐ray Crystallography
Authors: Sekiguchi Satoshi , Akagi Megumi , Naito Junpei , Yamamoto Yoko , Taji Hiromi , Kuwahara Shunsuke , Watanabe Masataka , Ozawa Yoshiki , Toriumi Koshiro , Harada Nobuyuki 
Published: March 2008

AbstractThe MαNP acid method has been applied to racemic aliphatic acetylene alcohols in order to simultaneously prepare enantiopure alcohols and to determine their absolute configurations by 1H NMR anisotropy. Racemic acetylene alcohols 6–8, 11, and 20 were esterified with MαNP acid (S)‐(+)‐1 to yield diastereomeric MαNP esters which were efficiently separated by HPLC on silica gel with separation factors α in the range 1.60–1.93. The 1H NMR anisotropy factors Δδ [= δ(2nd fr.) – δ(1st fr.)] were calculated from the data of the first‐ (22a–27a) and second‐eluted MαNP esters (22b–27b). The absolute configurations of the first‐eluted esters were determined from the distribution of Δδ values in the MαNP sector rule. In the case of MαNP ester 26b, the assigned absolute configuration was confirmed by X‐ray crystallography. The solvolysis of MαNP esters yielded enantiopure acetylene alcohols 5–8 with established absolute configurations. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)
Anthraquinones as Artificial DNA Building Blocks
Authors: Bouquin Nicolas , Malinovskii Vladimir L. , Häner Robert 
Published: March 2008

AbstractSynthesis and properties of oligodeoxynucleotides containing anthraquinone‐derived building blocks with flexible linkers are described. Starting from the 1,4‐, 1,5‐, 1,8‐ and 2,6‐dihydroxyanthraquinone isomers, the corresponding phosphoramidites were prepared and incorporated into oligonucleotides. The site of linker attachment was found to be of critical importance for hybrid stability. Whereas the 2,6‐isomer led to a significant stabilization, all other isomers had a negative effect on the stability of the duplex. Spectroscopic studies showed that the anthraquinones behave as fluorescence quenchers. Models of anthraquinone‐modified double‐stranded hybrids are proposed. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)
The Structure of the O‐Chain Polysaccharide from the Gram‐Negative Endophytic Bacterium Burkholderia phytofirmans Strain PsJN
Authors: Silipo Alba , Ierano Teresa , Lanzetta Rosa , Molinaro Antonio , Parrilli Michelangelo 
Published: March 2008

AbstractThe O‐chain polysaccharide of the lipopolysaccharide from the endophytic bacterium Burkholderia phytofirmans strain PsJN was characterized by means of a combined chemical degradation approach and NMR spectroscopic analyses. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)
MC1R variants, melanoma and red hair color phenotype: A meta‐analysis
Authors: Raimondi Sara , Sera Francesco , Gandini Sara , Iodice Simona , Caini Saverio , Maisonneuve Patrick , Fargnoli Maria Concetta 
Published: March 2008

AbstractMelanocortin‐1‐receptor (MC1R) is one of the major genes that determine skin pigmentation. MC1R variants were suggested to be associated with red hair, fair skin, and an increased risk of melanoma. We performed a meta‐analysis on the association between the 9 most studied MC1R variants (p.V60L, p.D84E, p.V92M, p.R142H, p.R151C, p.I155T, p.R160W, p.R163Q and p.D294H) and melanoma and/or red hair, fair skin phenotype. Eleven studies on MC1R and melanoma, and 9 on MC1R and phenotype were included in the analysis. The 7 variants p.D84E, p.R142H, p.R151C, p.I155T, p.R160W, p. R163Q and p.D294H were significantly associated with melanoma development, with ORs (95%CI) ranging from 1.42 (1.09–1.85) for p.R163Q to 2.45 (1.32–4.55) for p.I155T. The MC1R variants p.R160W and p.D294H were associated both with red hair and fair skin, while p.D84E, p.R142H, and p.R151C were strongly associated with red hair only‐ ORs (95%CI) ranged from 2.99 (1.51–5.91) for p.D84E to 8.10 (5.82–11.28) for p.R151C. No association with melanoma or phenotype was found for p.V60L and p.V92M variants. In conclusion this meta‐analysis provided evidence that some MC1R variants are associated both with melanoma and phenotype, while other are only associated with melanoma development. These results suggest that MC1R variants could play a role in melanoma development both via pigmentary and non‐pigmentary pathways. © 2008 Wiley‐Liss, Inc.
Socioeconomic inequalities and oral cancer risk: A systematic review and meta‐analysis of case‐control studies
Authors: Conway David I. , Petticrew Mark , Marlborough Helen , Berthiller Julien , Hashibe Mia , Macpherson Lorna M.D. 
Published: March 2008

AbstractThere is uncertainty and limited recognition of the relationship between socioeconomic inequalities and oral cancer. We aimed to quantitatively assess the association between socioeconomic status (SES) and oral cancer incidence risk. A systematic review of case‐control studies obtained published and unpublished estimates of the SES risk related to oral cancer. Studies were included which reported odds ratios (ORs) and corresponding 95% CIs of oral cancer with respect to SES, or if the estimates could be calculated or obtained. Meta‐analyses were performed on subgroups: SES measure, age, sex, global region, development level, time‐period and lifestyle factor adjustments; while sensitivity analyses were conducted based on study methodological issues. Forty‐one studies provided 15,344 cases and 33,852 controls which met our inclusion criteria. Compared with individuals who were in high SES strata, the pooled ORs for the risk of developing oral cancer were 1.85 (95%CI 1.60, 2.15; n = 37 studies) for those with low educational attainment; 1.84 (1.47, 2.31; n = 14) for those with low occupational social class; and 2.41 (1.59, 3.65; n = 5) for those with low income. Subgroup analyses showed that low SES was significantly associated with increased oral cancer risk in high and lower income‐countries, across the world, and remained when adjusting for potential behavioural confounders. Inequalities persist but are perhaps reducing over recent decades. Oral cancer risk associated with low SES is significant and comparable to lifestyle risk factors. Our results provide evidence to steer health policy which focus on lifestyles factors toward an integrated approach incorporating measures designed to tackle the root causes of disadvantage. © 2008 Wiley‐Liss, Inc.
Targeting of the N‐terminal coiled coil oligomerization interface by a helix‐2 peptide inhibits unmutated and imatinib‐resistant BCR/ABL
Authors: Beissert Tim , Hundertmark Alena , Kaburova Velina , Travaglini Lorena , Mian Afsar A. , Nervi Clara , Ruthardt Martin 
Published: March 2008

AbstractThe BCR/ABL oncogene is responsible for the phenotype of Philadelphia chromosome‐positive (Ph+) leukemia. BCR/ABL exhibits an aberrant ABL‐tyrosine kinase activity. The treatment of advanced Ph+ leukemia with selective ABL‐kinase inhibitors such as Imatinib, Nilotinib and Dasatinib is initially effective but rapidly followed by resistance mainly because of specific mutations in BCR/ABL. Tetramerization of ABL through the N‐terminal coiled‐coil region (CC) of BCR is essential for the ABL‐kinase activation. Targeting the CC‐domain forces BCR/ABL into a monomeric conformation reduces its kinase activity and increases the sensitivity for Imatinib. We show that (i) targeting the tetramerization by a peptide representing the Helix‐2 of the CC efficiently reduced the autophosphorylation of both unmutated and mutated BCR/ABL; (ii) Helix‐2 inhibited the transformation potential of BCR/ABL independently of the presence of mutations; and (iii) Helix‐2 efficiently cooperated with Imatinib as revealed by their effects on the transformation potential and the factor‐independence related to BCR/ABL with the exception of mutant T315I. These findings support earlier observations that BCR/ABL harboring the T315I mutation have a transformation potential that is at least partially independent of its kinase activity. These data provide evidence that the inhibition of tetramerization inhibits BCR/ABL‐mediated transformation and can contribute to overcome Imatinib‐resistance. © 2008 Wiley‐Liss, Inc.
Play and emotional availability in young children with Down syndrome
Authors: Venuti Paola , de Falco Simona , Giusti Zeno , Bornstein Marc H. 
Published: March 2008

AbstractThis study investigates mother–child interaction and its associations with play in children with Down syndrome (DS). There is consensus that mother–child interaction during play represents an important determinant of typical children's play development. Concerning children with DS, few studies have investigated mother–child interaction in terms of the overall emotional quality of dyadic interaction and its effect on child play. A sample of 28 children with DS (M age = 3 years) took part in this study. In particular, we studied whether the presence of the mother in an interactional context affects the exploratory and symbolic play of children with DS and the interrelation between children's level of play and dyadic emotional availability. Children showed significantly more exploratory play during collaborative play with mothers than during solitary play. However, the maternal effect on child symbolic play was higher in children of highly sensitive mothers relative to children whose mothers showed lower sensitivity, the former displaying more symbolic play than the latter in collaborative play. Results offer some evidence that dyadic emotional availability and child play level are associated in children with DS, consistent with the hypothesis that dyadic interactions based on a healthy level of emotional involvement may lead to enhanced cognitive functioning.
Effectiveness of the home‐start parenting support program: Behavioral outcomes for parents and children
Authors: Asscher Jessica J. , Hermanns Jo M.A. , Deković Maja 
Published: March 2008

AbstractThis study examined effectiveness of Home‐Start, a program designed to support parents with young children. The aims were (a) to examine whether Home‐Start improved maternal well‐being and (b) to examine whether Home‐Start led to changes in the behavior of mothers or children. Self‐reported and observational data were collected in two waves, using data from 54 mothers and their children between 1.5 and 3.5 years of age who participated in this intervention program for 6 months. These data were compared to 51 comparison families who reported need for parenting support. The results showed a significant improvement in perceived parenting competence, but no effects on maternal depressive moods. Mixed results were found for parenting behavior: Parental consistency and observed sensitivity improved significantly in the Home‐Start group whereas no effects were found on the other parenting variables. Child behavioral problems seemed to diminish at the second measurement in both groups, and therefore these changes cannot be attributed to Home‐Start.