bluuebunny/crossref_metadata_2025_split huggingface dataset:
Brønsted Acid‐Catalyzed Three‐Component Hosomi–Sakurai Reactions
Authors: Kampen Daniela , Ladépêche Arnaud , Claßen Gerrit , List Benjamin 
Published: April 2008

AbstractAldehydes react with silyl ethers or the corresponding alcohols and allylsilanes in the presence of catalytic amounts of 2,4‐dinitrobenzenesulfonic acid (DNBA) to provide a wide range of homoallylic ethers in moderate to high yields.
Reduced dose of lenograstim is as efficacious as standard dose of filgrastim for peripheral blood stem cell mobilization and transplantation: A randomized study in patients undergoing autologous peripheral stem cell transplantation
Authors: Ataergin Selmin , Arpaci Fikret , Turan Mustafa , Solchaga Luis , Cetin Turker , Ozturk Mustafa , Ozet Ahmet , Komurcu Seref , Ozturk Bekir 
Published: April 2008

AbstractIn vitro studies have demonstrated a 27% increased efficacy of lenograstim over filgrastim. However, equal doses of 10 μg/kg/day of filgrastim and lenograstim have been recommended for mobilization of CD34+ cells without associated chemotherapy. In this study, we investigated whether a 25% reduced dose of lenograstim at 7.5 μg/kg/day is equavalent to 10 μg/kg/day filgrastim for autologous peripheral blood stem cell (PBSC) mobilization and transplantation. A total of 40 consecutive patients were randomized to either filgrastim (n = 20) or lenograstim (n = 20). The two cohorts were similar in regard to disease, sex, body weight, body surface area, conditioning regimens, previous chemotherapy cycles and radiotherapy. Each growth factor was administered for 4 consecutive days. The first PBSC apheresis was done on the 5th day. In the posttransplant period, the same G‐CSF was given at 5 μg/kg/day until leukocyte engraftment. Successful mobilization was achieved in 95% of patients. Successful mobilization with the first apheresis, was achieved in 10/20 (50%) patients in the filgrastim group versus 9/20 (46%) patients in the lenograstim group. No significant difference was seen in the median number of CD34+cells mobilized, as well as the median number of apheresis, median volume of apheresis, percentage of CD34+ cells, and CD34+ cell number. Leukocyte and platelet engraftments, the number of days requiring G‐CSF and parenteral antibiotics, the number of transfusions were similar in both groups in the posttransplant period. Lenograstim 7.5 μg/kg/day is as efficious as filgrastim 10 μg/kg/day for autologous PBSC mobilization and transplantation. Am. J. Hematol., 2008. © 2008 Wiley‐Liss, Inc.
Compound heterozygosity for two MSH6 mutations in a patient with early onset colorectal cancer, vitiligo and systemic lupus erythematosus
Authors: Rahner Nils , Höefler Gerald , Högenauer Christoph , Lackner Caroline , Steinke Verena , Sengteller Marlies , Friedl Waltraut , Aretz Stefan , Propping Peter , Mangold Elisabeth , Walldorf Constanze 
Published: April 2008

AbstractLynch syndrome (hereditary non‐polyposis colorectal cancer, HNPCC) is an autosomal dominant condition caused by heterozygous germline mutations in the DNA mismatch repair (MMR) genes MLH1, MSH2, MSH6, or PMS2. Rare cases have been reported of an inherited bi‐allelic deficiency of MMR genes, associated with multiple café‐au‐lait spots, early onset CNS tumors, hematological malignancies, and early onset gastrointestinal neoplasia. We report on a patient with vitiligo in segments of the integument who developed systemic lupus erythematosus (SLE) at the age of 16, and four synchronous colorectal cancers at age 17 years. Examination of the colorectal cancer tissue showed high microsatellite instability (MSI‐H) and an exclusive loss of expression of the MSH6 protein. Immunohistochemical analysis of normal colon tissue also showed loss of MSH6, pointing to a bi‐allelic MSH6 mutation. Sequencing of the MSH6 gene showed the two germline mutations; c.1806_1809delAAAG;p.Glu604LeufsX5 and c.3226C > T;p.Arg1076Cys. We confirmed that the two mutations are on two different alleles by allele‐specific PCR. To our knowledge, neither parent is clinically affected. They did not wish to be tested for the mutations identified in their daughter. These data suggest that bi‐allelic mutations of one of the MMR genes should be considered in patients who develop early‐onset multiple HNPCC‐associated tumors and autoimmune disorders, even in absence of either hematological malignancies or brain tumors. © 2008 Wiley‐Liss, Inc.
No major role for the EMX2 gene in schizencephaly
Authors: Merello Elisa , Swanson Eric , De Marco Patrizia , Akhter Murtaza , Striano Pasquale , Rossi Andrea , Cama Armando , Leventer Richard J. , Guerrini Renzo , Capra Valeria , Dobyns William B. 
Published: April 2008

AbstractSchizencephaly (SCH) is a rare disorder of cerebral cortical development, characterized by full thickness clefts spanning the wall of the cerebral hemispheres that are lined and surrounded by polymicrogyric cortex. Based on pathological analysis, SCH was originally considered to have multiple causes including infectious and vascular injuries, and toxic agents. However, a few reports of familial SCH have suggested a possible genetic etiology. Ten years ago two articles identified EMX2 as the first causative gene for human SCH in 13 of 18 patients, although for several putative mutations no pathogenic role was demonstrated. Here, we reinterpret the original articles as showing a significantly lower mutational rate (17%) than originally reported (72%), and provide results of EMX2 sequencing in 39 new SCH patients, detecting no pathogenic mutations. We conclude that the reported association between SCH and EMX2 mutations is not adequately supported by current data, and that diagnostic testing of EMX2 is not justified, as any results would be uninterpretable. © 2008 Wiley‐Liss, Inc.
Synthesis and characterization of aromatic/aliphatic co‐polyureas
Authors: Li Xue‐lian , Chen Da‐jun 
Published: April 2008

AbstractIn the present work, a series of aromatic/aliphatic co‐polyureas have been synthesized from 4,4‐diphenylmethane diisocyanate (MDI), m‐phenylene diamine (m‐PDA), and 1,6‐diaminohexane (HDA) in DMAc by a two‐stage solution polymerization route. Characterizations of the polyurea products have been carried out by 1H‐nuclear magnetic resonance (NMR) and Fourier transform infrared (FT‐IR) spectroscopic techniques. Thermal properties of the polyurea samples have been investigated by differential scanning calorimetry and thermogravimetric analysis. The mechanical properties of the polyurea samples have been measured. The results show that the polyurea samples with the expected structure have been synthesized. The results of DSC analysis show the glass transition temperatures of the co‐polyurea samples decrease with the increase of HDA content, and fit the Fox equation well. TGA data of the polyurea samples indicate that thermal stability of the aromatic polyurea is better than that of the co‐polyureas. The thermal degradation activation energies of the co‐polyureas are ∼60–70 kJ/mol. The results of mechanical measurement show that the initial modulus and tensile strength of the co‐polyurea samples decrease with the increase of HDA content. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Dispersion of nanoclay into polypropylene with carbon dioxide in the presence of maleated polypropylene
Authors: Nguyen Quang T. , Baird Donald G. 
Published: April 2008

AbstractThe effect of maleic anhydride grafted polypropylene (PP‐g‐MA) on the mechanical and rheological properties of polypropylene (PP)–clay nanocomposites prepared with nanoclay expanded with CO2 and direct melt blending was studied. The results from the studies of the mechanical properties, rheological properties, and transmission electron microscopy show that when PP‐g‐MA was combined with the technique that used CO2, greater enhancements in the mechanical properties and degree of dispersion of nanoclay in PP were observed. Furthermore, yieldlike behavior in the viscosity and a tail in the low‐frequency behavior of the elastic modulus was attributed to the reaction of PP‐g‐MA with the nanoclay surface and not exfoliation. A fairly well‐dispersed morphology was observed for concentrations as high 6.8 wt % clay when the clay was expanded and mixed with CO2. At this concentration, mechanical properties such as yield strength and modulus increased by as much as 13 and 69%, respectively, relative to the pure PP. Furthermore, the modulus of the composite samples prepared with PP‐g‐MA and CO2 was some 15% higher than that of samples prepared by direct melt compounding (without the use of CO2). © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Synthesis of a novel star polymer consisting of a dendritic polyamidoamine core and polystyrene arms and its self‐assembly to form large multimolecular micelles
Authors: Zhao Yili , Song Yantao , Jiang Wei , Zhang Bao , Li Yapeng , Sha Ke , Wang Shuwei , Chen Liang , Ma Lina , Wang Jingyuan 
Published: April 2008

AbstractThis work is focused on the synthesis and self‐assembly of novel dendritic star polymers with a dendritic polyamidoamine core and many linear polystyrene arms. The polymers can synchronously form unimolecular micelles (ca. 10 nm) and large multimolecular micelles (ca. 100 nm) in selected solvents (tetrahydrofuran/methanol) at room temperature. Atomic force microscopy, scanning electron microscopy, and dynamic light scattering measurements have provided direct evidence that the large micelles are a kind of multimicelle aggregate with the basic building units of unimolecular micelles. Accordingly, a possible self‐assembly process is put forward, and a new aggregate model, termed multimicelle aggregate, is suggested to explain the formation of the large micelles. In the multimicelle aggregate model, the large micelles are the aggregates of small micelles associated by intermicellar interactions such as hydrogen bonds and p–p stacking interactions. It is the first demonstration of the self‐assembly mechanism for the large multimolecular micelles generated from the solution self‐assembly of dendritic star polymers. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Effects of reactive melt mixing on the morphology and thermal behavior of linear low‐density polyethylene/rubber blends
Authors: Penco Maurizio , Sciucca Stefania Della , Passaglia Elisa , Giordani Guido , Coiai Serena , Di Landro Luca 
Published: April 2008

AbstractLinear low‐density polyethylene (LLDPE)/polybutadiene (PB) and LLDPE/poly(styrene‐b‐butadiene‐b‐styrene) (SBS) binary blends were prepared by simple melt mixing or by reactive blending in the presence of a free‐radical initiator, and for comparison, pure LLDPE was treated under the same conditions with a comparable free‐radical initiator concentration. The effect of the reactive melt mixing on the morphology of the blends was studied with transmission electron microscopy, and the corresponding particle size distributions were analyzed and compared to highlight the effects of the crosslinking and grafting phenomena. Thermal properties of the obtained materials were investigated with differential scanning calorimetry and dynamic mechanical thermal analysis (DMTA). In particular, the effect of the reactive mixing parameters on the amorphous phase mobility was investigated. The influence of the chemical modification on the crystallization behavior of LLDPE, neat and blended with PB and SBS, was also studied with dynamic and isothermal differential scanning calorimetry tests, and the isothermal thermograms were analyzed in light of the Avrami equation. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
A comparative study of the cure characteristics, processability, mechanical properties, ageing, and morphology of rice husk ash, silica and carbon black filled 75 : 25 NR/EPDM blends
Authors: Arayapranee Wanvimon , Rempel Garry L. 
Published: April 2008

AbstractThe performance of rice husk ash (RHA), obtained by burning rice husks, as a filler for natural rubber (NR)/ethylene–propylene–diene monomer (EPDM) blends was investigated. For comparison purposes, two commercial reinforcing fillers, silica and carbon black were also used. A fixed 75 : 25 blend ratio (wt %) of NR and EPDM was prepared using a two‐stage conventional mixing procedure. Filler loading was varied from 0 to 60 parts per hundred of resin (phr) at 15 phr intervals. The results indicated that RHA offers processing advantages over silica and carbon black. The use of RHA as an additional filler provided almost no improvement in the tensile strength and abrasion resistance of the 75 : 25 NR/EPDM blends. The ozone resistance of the blends was inferior to those obtained from the addition of RHA. However, RHA was better in resilience property than that of silica and carbon black. Scanning electron micrographs revealed that the dispersion of RHA filler in the rubber matrix is discontinuous, which in turn generates weak structure when compared with carbon black and silica. According to these observations, RHA could be used as a diluent filler for the 75 : 25 NR/EPDM blend, while silica and carbon black can be used as a reinforcing filler. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Study on the structure of mangrove polyflavonoid tannins with MALDI‐TOF mass spectrometry
Authors: Oo C. W. , Pizzi A. , Pasch H. , Kassim M. J. 
Published: April 2008

AbstractMatrix‐assisted laser desorption/ionization time‐of‐flight (MALDI‐TOF) mass spectrometry is a suitable method for examining polyflavonoid tannin oligomers as it is capable to determine aspects of their oligomeric structure and characteristics, which are otherwise too difficult to determine by other techniques. It has been possible to determine by MALDI‐TOF for Rhizophora apiculata mangrove polyflvonoid tannins that: (i) procyanidins oligomers formed by catechin/epicatechin, epigallocatechin, and epicatechin gallate monomers are present in great proportions; (ii) oligomers, up to nonamers, in which the repeating unit at 528–529 Da is a catechin gallate dimer that has lost both the gallic acid residues and an hydroxy group which are the predominant species; (iii) oligomers of the two types covalently linked to each other also occur. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Synthesis and Anticancer Activity of New 1‐Substituted‐6H‐pyrido[4,3‐b]carbazole Derivatives
Authors: Tylińska Beata , Jasztold‐Howorko Ryszard , Mastalarz Henryk , Szczaurska‐Nowak Katarzyna , Wietrzyk Joanna 
Published: April 2008

AbstractThis study examines the synthesis and cytostatic activity of new 5,6‐dimethyl‐1‐substituted‐6H‐pyrido[4,3‐b]carbazole derivatives. Their structures were confirmed by 1H‐NMR and elemental analysis. Seven of the new compounds were tested by the SRB method in vitro against human lung cancer (A549) and human kidney cancer (A498) cell lines. Biological tests indicated remarkable cytostatic effects of four compounds tested in comparison with ellipticine and cisplatin as reference drugs. One particular compound 3c was about four times more active on A498 than ellipticine with similar activity on the A549 cell line, and outperformed cisplatin activity on both tumor cell lines.
Investigations Concerning the Correlation of COX‐1 Inhibitory and Hydroxyl Radical Scavenging Activity
Authors: Scholz Michael , Ulbrich Holger , Mattern Andreas , Kramb Jan‐Peter , Kiefer Werner , Dannhardt Gerd 
Published: April 2008

AbstractThe aim was to study the COX‐1 inhibiting efficacy in context with hydroxyl radical scavenging properties of compounds bearing a carboxylic acid and ester function, respectively. In general, the acids are more potent radical scavengers than the corresponding esters but there is no clear correlation with their COX‐1 inhibiting potencies. A feasible scavenging mechanism of carboxylic acids is discussed.
The vortical response to penetrative convection and the associated gravity‐wave generation
Authors: Lane Todd P. 
Published: April 2008

AbstractThis study documents the vortical motions that arise due to penetrative convective updraughts. Using an idealized axisymmetric model of dry thermals it is shown that in a stable environment the baroclinic generation of vorticity forms a circulation that opposes updraught overshoot and manifests the first signature of gravity waves emanating from the thermal. Continued baroclinic generation of vorticity of oscillating sign completes the first full wavelength and populates the wave packet. These examples provide an alternate description of the generation of gravity waves by penetrative convection and provide further insight into the morphology of the wave source Copyright © 2008 Royal Meteorological Society
Hydrological aspects of meteorological verification
Authors: Pappenberger F. , Scipal K. , Buizza R. 
Published: April 2008

AbstractAll major weather forecast centres verify meteorological forecasts as a normal part of their operational duties, with verifications usually based on variables and methods of meteorological relevance. These forecasts are then often used to drive hydrological models, and this article demonstrates that a considerable gap exists between current meteorological practice and hydrological needs. This article discusses this gap in terms of the type of variables; the domain and resolution; the importance of choosing appropriate thresholds; and the smoothing and accumulation period. A list of recommendations for a user‐focused evaluation is given in the conclusions. We suggest that the meteorological community, and specifically the forecast centres, should consider making these adjustments and producing additional products suitable for hydrological applications. Copyright © 2008 Royal Meteorological Society
Percutaneous treatment of an iatrogenic cardiac fistula
Authors: Patterson Mark S. , Vaina Sophia , Serruys Patrick W. 
Published: April 2008

AbstractCoronary fistulae, defined as communications between coronary arteries and cardiac chambers or veins, are uncommon. We present a case where a fistula was inadvertently caused by the surgical anastomosis of an arterial coronary artery bypass graft to a coronary vein. This produced two coronary problems, the unrevascularized Cx territory and a coronary arteriovenous fistula, and left the patient with symptoms. Each of these problems was addressed in a tailored percutaneous intervention by deploying ostial and distal stents to revascularize the Cx, followed by coils to block the distal section of the graft. © 2008 Wiley‐Liss, Inc.
Low gradient aortic stenosis: Assessment, treatment, and outcome
Authors: Higgins James R. , Arimie Raluca , Currier Jesse 
Published: April 2008

AbstractAortic stenosis is a commonly encountered valvular disorder in the treatment of cardiovascular disease. Generally, symptomatic patients who undergo valve replacement experience a vast reduction in symptoms and a great improvement in survival. A subset of symptomatic patients in whom management is less clear are those with a small transvalvular gradient and low cardiac output, or low gradient aortic stenosis. The assessment, treatment, and outcome of this unique group of patients will be reviewed. © 2008 Wiley‐Liss, Inc.
Oxidative Homolysis of a Nitrosylchromium Complex
Authors: Song Wenjing , Bakac Andreja 
Published: April 2008

AbstractMetal(III)–polypyridine complexes [M(NN)3]3+ (M=Ru or Fe; NN=bipyridine (bpy), phenanthroline (phen), or 4,7‐dimethylphenanthroline (Me2‐phen)) oxidize the nitrosylpentaaquachromium(III) ion, [CraqNO]2+, with an overall 4:1 stoichiometry, 4 [Ru(bpy)3]3++[CraqNO]2++2 H2O→4 [Ru(bpy)3]2++[Craq]3++NO3−+4 H+. The kinetics follow a mixed second‐order rate law, −d[[M(NN)3]3+]/dt=nk[[M(NN)3]3+][[CraqNO]2+], in which k represents the rate constant for the initial one‐electron transfer step, and n=2–4 depending on reaction conditions and relative rates of the first and subsequent steps. With [CraqNO]2+ in excess, the values of nk are 283 M−1 s−1 ([Ru(bpy)3]3+), 7.4 ([Ru(Me2‐phen)3]3+), and 5.8 ([Fe(phen)3]3+). In the proposed mechanism, the one‐electron oxidation of [CraqNO]2+ releases NO, which is further oxidized to nitrite, k=1.04×106 M−1 s−1, 6.17×104, and 1.12×104 with the three respective oxidants. Further oxidation yields the observed nitrate. The kinetics of the first step show a strong correlation with thermodynamic driving force. Parallels were drawn with oxidative homolysis of a superoxochromium(III) ion, [CraqOO]2+, to gain insight into relative oxidizability of coordinated NO and O2, and to address the question of the “oxidation state” of coordinated NO in [CraqNO]2+.
On the Way to Selective PARP‐2 Inhibitors. Design, Synthesis, and Preliminary Evaluation of a Series of Isoquinolinone Derivatives
Authors: Pellicciari Roberto , Camaioni Emidio , Costantino Gabriele , Formentini Laura , Sabbatini Paola , Venturoni Francesco , Eren Gökçen , Bellocchi Daniele , Chiarugi Alberto , Moroni Flavio 
Published: April 2008

AbstractPARP‐1 and PARP‐2 are members of the family of poly(ADP‐ribose)polymerases, which are involved in the maintenance of genomic integrity under conditions of genotoxic stimuli. The different roles of the two isoforms under pathophysiological conditions have not yet been fully clarified, and this is partially due to the lack of selective inhibitors. We report herein the synthesis and preliminary pharmacological evaluation of a large series of isoquinolinone derivatives as PARP‐1/PARP‐2 inhibitors. Among them, we identified the 5‐benzoyloxyisoquinolin‐1(2 H)‐one derivative as the most selective PARP‐2 inhibitor reported so far, with a PARP‐2/PARP‐1 selectivity index greater than 60.
Competitive Activation of CH and CX Bonds in Reactions of Pt+ with CH3X (X=F,Cl): Experiment and Theory
Authors: Zhao Xiang , Hopkinson Alan C. , Bohme Diethard K. 
Published: April 2008

AbstractThe reactions of Pt+ with CH3X (X=F, Cl) are studied experimentally by employing an inductively coupled plasma/selected‐ion flow tube tandem mass spectrometer and theoretically by density functional theory. Dehydrogenation and HX elimination are found to be the primary reaction channels in the remarkably different ratios of 95:5 and 60:40 in the fast reactions of Pt+ with CH3F and CH3Cl, respectively. The observed kinetics are consistent with quantum chemistry calculations, which indicate that both channels in the reaction with CH3F are exothermic with ground‐state Pt+(2D), but that HF elimination is prohibited kinetically because of a transition state that lies above the reactant entrance. The observed HF‐elimination channel is attributed to a slow reaction of CH3F with excited‐state Pt+(4F) for which calculations predict a small barrier. The calculations also show that both the HCl‐elimination and dehydrogenation channels observed with CH3Cl are thermodynamically and kinetically allowed, although the state‐specific product distributions could not be ascertained experimentally. Further CH3F addition is observed with the primary products to produce PtCH2+(CH3F)1,2 and PtCHF+(CH3F)1,2. With CH3Cl, sequential HCl elimination is observed with PtCH2+ to form PtCnH2n+ with n=2, 3, which then add CH3Cl sequentially to form PtC2H4+(CH3Cl)1–3 and PtC3H6+(CH3Cl)1,2. Also, sequential addition is observed for PtCHCl+ to form PtCHCl+(CH3Cl)1,2.
Understanding the Supramolecular Self‐Assembly of the Fullerene Derivative PCBM on Gold Surfaces
Authors: Wang Yang , Alcamí Manuel , Martín Fernando 
Published: April 2008

AbstractWe report a DFT study on the self‐assembly of the fullerene derivative PCBM on the Au(111) surface. Recent STM experiments (Angew. Chem. 2007, 119, 8020–8023[1]) show a coverage‐dependent transition of the adsorption and self‐assembly of PCBM on this surface. To understand the origin of this observation, we compute the geometries and relative energies of ten PCBM dimers and four tetramers. The calculations show that the self‐assembly of PCBM at high coverage is mainly controlled by hydrogen bonding between the PCBM tails. Due to the large size of the fullerene cage, the hydrogen bonds are formed far away from the surface; hence they are very similar to those found in the gas phase. This picture successfully explains the observed site‐insensitive adsorption at high coverage and the 2D arrangement of PCBM on the surface.